diff mbox series

[v3,2/2] dt-bindings: iio: Add ltc2983 documentation

Message ID 20191004135519.191657-2-nuno.sa@analog.com (mailing list archive)
State New, archived
Headers show
Series [v3,1/2] iio: temperature: Add support for LTC2983 | expand

Commit Message

Nuno Sa Oct. 4, 2019, 1:55 p.m. UTC
Document the LTC2983 temperature sensor devicetree bindings.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
---
Changes in v2:
 * Drop maxItems in non-array elements;
 * Set adi,mux-delay-config-us instead of adi,mux-delay-config;
 * Wrapped lines at 80 char;
 * Added comas to enum elements;
 * Use real units in adi,excitation-current;
 * Moved some enums to minimum and maximum;
 * Grouped patternProperties and moved reg property as a generic property.

Changes in v3:
 * Add meaning to adi,sensor-type values which are not const;
 * Add meaning to adi,filter-notch-freq values;
 * Break up adi,sensor-config into human readable elements;
 * Set maxItems/minItems at the same identation as allOf in adi,custom-sensor;
 * Fixed the maximum value for adi,sensor-type for sensors with custom support;
 * Changed license to GPL-2.0-only as it should be for new bindings;
 * Changed spi0 to spi in the dts example;
 * Updated the dts example to the new properties.

 .../bindings/iio/temperature/adi,ltc2983.yaml | 479 ++++++++++++++++++
 MAINTAINERS                                   |   1 +
 2 files changed, 480 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml

Comments

Jonathan Cameron Oct. 6, 2019, 10:29 a.m. UTC | #1
On Fri, 4 Oct 2019 15:55:19 +0200
Nuno Sá <nuno.sa@analog.com> wrote:

> Document the LTC2983 temperature sensor devicetree bindings.
> 
> Signed-off-by: Nuno Sá <nuno.sa@analog.com>
I'm out of my depth on this one so will be relying on Rob or Mark to take
a look.

Thanks,

Jonathan

> ---
> Changes in v2:
>  * Drop maxItems in non-array elements;
>  * Set adi,mux-delay-config-us instead of adi,mux-delay-config;
>  * Wrapped lines at 80 char;
>  * Added comas to enum elements;
>  * Use real units in adi,excitation-current;
>  * Moved some enums to minimum and maximum;
>  * Grouped patternProperties and moved reg property as a generic property.
> 
> Changes in v3:
>  * Add meaning to adi,sensor-type values which are not const;
>  * Add meaning to adi,filter-notch-freq values;
>  * Break up adi,sensor-config into human readable elements;
>  * Set maxItems/minItems at the same identation as allOf in adi,custom-sensor;
>  * Fixed the maximum value for adi,sensor-type for sensors with custom support;
>  * Changed license to GPL-2.0-only as it should be for new bindings;
>  * Changed spi0 to spi in the dts example;
>  * Updated the dts example to the new properties.
> 
>  .../bindings/iio/temperature/adi,ltc2983.yaml | 479 ++++++++++++++++++
>  MAINTAINERS                                   |   1 +
>  2 files changed, 480 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> new file mode 100644
> index 000000000000..b7101a0e84db
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> @@ -0,0 +1,479 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/temperature/adi,ltc2983.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Analog Devices LTC2983 Multi-sensor Temperature system
> +
> +maintainers:
> +  - Nuno Sá <nuno.sa@analog.com>
> +
> +description: |
> +  Analog Devices LTC2983 Multi-Sensor Digital Temperature Measurement System
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/2983fc.pdf
> +
> +properties:
> +  compatible:
> +    enum:
> +      - adi,ltc2983
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  adi,temperature-celcius:
> +    description:
> +      If this property is present, the temperature is reported in Celsius.
> +    type: boolean
> +
> +  adi,mux-delay-config-us:
> +    description:
> +      The LTC2983 performs 2 or 3 internal conversion cycles per temperature
> +      result. Each conversion cycle is performed with different excitation and
> +      input multiplexer configurations. Prior to each conversion, these
> +      excitation circuits and input switch configurations are changed and an
> +      internal 1ms delay ensures settling prior to the conversion cycle in most
> +      cases. An extra delay can be configured using this property. The value is
> +      rounded to nearest 100us.
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +      - maximum: 255
> +
> +  adi,filter-notch-freq:
> +    description:
> +      Set's the default setting of the digital filter. The default is
> +      simultaneous 50/60Hz rejection.
> +      0 - 50/60Hz rejection
> +      1 - 60Hz rejection
> +      2 - 50Hz rejection
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +      - minimum: 0
> +      - maximum: 2
> +
> +  '#address-cells':
> +    const: 1
> +
> +  '#size-cells':
> +    const: 0
> +
> +patternProperties:
> +  ".*@([1-9]|1[0-9]|20)$":
> +    type: object
> +
> +    properties:
> +      reg:
> +        description: |
> +          The channel number. It can be connected to one of the 20 channels of
> +          the device.
> +        minimum: 1
> +        maximum: 20
> +
> +    required:
> +      - reg
> +
> +    patternProperties:
> +      "^thermocouple@.*":
> +        type: object
> +        description: |
> +          Represents a thermocouple sensor which is connected to one of the device
> +          channels.
> +
> +        properties:
> +          adi,sensor-type:
> +            description: |
> +              Identifies the type of thermocouple connected to the device.
> +              1 - Type J Thermocouple
> +              2 - Type K Thermocouple
> +              3 - Type E Thermocouple
> +              4 - Type N Thermocouple
> +              5 - Type R Thermocouple
> +              6 - Type S Thermocouple
> +              7 - Type T Thermocouple
> +              8 - Type B Thermocouple
> +              9 - Custom Thermocouple
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32
> +              - minimum: 1
> +              - maximum: 9
> +
> +          adi,single-ended:
> +            description: |
> +              Boolean property which set's the thermocouple as single-ended.
> +            type: boolean
> +
> +          adi,sensor-oc-current-microamp:
> +            description: |
> +              This property set's the pulsed current value applied during
> +              open-circuit detect.
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32
> +              - enum: [10, 100, 500, 1000]
> +
> +          adi,cold-junction-handle:
> +            description: |
> +              Phandle which points to a sensor object responsible for measuring
> +              the thermocouple cold junction temperature.
> +            $ref: "/schemas/types.yaml#/definitions/phandle"
> +
> +          adi,custom-sensor:
> +            description: |
> +              This is a table, where each entry should be a pair of
> +              voltage(mv)-temperature(K). The entries must be given in nv and uK
> +              so that, the original values must be multiplied by 1000000. For
> +              more details look at table 69 and 70.
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/int64-array
> +            minItems: 6
> +            maxItems: 128
> +
> +        required:
> +          - adi,sensor-type
> +
> +      "^diode@.*":
> +        type: object
> +        description: |
> +          Represents a diode sensor which is connected to one of the device
> +          channels.
> +
> +        properties:
> +          adi,sensor-type:
> +            description: Identifies the sensor as a diode.
> +            const: 28
> +
> +          adi,single-ended:
> +            description: Boolean property which set's the diode as single-ended.
> +            type: boolean
> +
> +          adi,three-conversion-cycles:
> +            description: |
> +              Boolean property which set's three conversion cycles removing
> +              parasitic resistance effects between the LTC2983 and the diode.
> +            type: boolean
> +
> +          adi,average-on:
> +            description: |
> +              Boolean property which enables a running average of the diode
> +              temperature reading. This reduces the noise when the diode is used
> +              as a cold junction temperature element on an isothermal block
> +              where temperatures change slowly.
> +            type: boolean
> +
> +          adi,excitation-current-microamp:
> +            description: |
> +              This property controls the magnitude of the excitation current
> +              applied to the diode. Depending on the number of conversions
> +              cycles, this property will assume different predefined values on
> +              each cycle. Just set the value of the first cycle (1l).
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32
> +              - enum: [10, 20, 40, 80]
> +
> +          adi,ideal-factor-value:
> +            description: |
> +              This property sets the diode ideality factor. The real value must
> +              be multiplied by 1000000 to remove the fractional part. For more
> +              information look at table 20 of the datasheet.
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32
> +
> +        required:
> +          - adi,sensor-type
> +
> +      "^rtd@.*":
> +        type: object
> +        description: |
> +          Represents a rtd sensor which is connected to one of the device channels.
> +
> +        properties:
> +          reg:
> +            minimum: 2
> +
> +          adi,sensor-type:
> +            description: |
> +              Identifies the type of RTD connected to the device.
> +              10 - RTD PT-10
> +              11 - RTD PT-50
> +              12 - RTD PT-100
> +              13 - RTD PT-200
> +              14 - RTD PT-500
> +              15 - RTD PT-1000
> +              16 - RTD PT-1000 (0.00375)
> +              17 - RTD NI-120
> +              18 - RTD Custom
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32
> +              - minimum: 10
> +              - maximum: 18
> +
> +          adi,rsense-handle:
> +            description: |
> +              Phandle pointing to a rsense object associated with this RTD.
> +            $ref: "/schemas/types.yaml#/definitions/phandle"
> +
> +          adi,number-of-wires:
> +            description: |
> +              Identifies the number of wires used by the RTD. Setting this
> +              property to 5 means 4 wires with Kelvin Rsense.
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32
> +              - enum: [2, 3, 4, 5]
> +
> +          adi,rsense-share:
> +            description: |
> +              Boolean property which enables Rsense sharing, where one sense
> +              resistor is used for multiple 2-, 3-, and/or 4-wire RTDs.
> +            type: boolean
> +
> +          adi,current-rotate:
> +            description: |
> +              Boolean property which enables excitation current rotation to
> +              automatically remove parasitic thermocouple effects. Note that
> +              this property is not allowed for 2- and 3-wire RTDs.
> +            type: boolean
> +
> +          adi,excitation-current-microamp:
> +            description: |
> +              This property controls the magnitude of the excitation current
> +              applied to the RTD.
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32
> +              - enum: [5, 10, 25, 50, 100, 250, 500, 1000]
> +
> +          adi,rtd-curve:
> +            description: |
> +              This property set the RTD curve used and the corresponding
> +              Callendar-VanDusen constants. Look at table 30 of the datasheet.
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32
> +              - minimum: 0
> +              - maximum: 3
> +
> +          adi,custom-sensor:
> +            description: |
> +              This is a table, where each entry should be a pair of
> +              resistance(ohm)-temperature(K). The entries added here are in uohm
> +              and uK. For more details values look at table 74 and 75.
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint64-array
> +            minItems: 6
> +            maxItems: 128
> +
> +        required:
> +          - adi,sensor-type
> +          - adi,rsense-handle
> +
> +        dependencies:
> +          adi,current-rotate: [ adi,rsense-share ]
> +
> +      "^thermistor@.*":
> +        type: object
> +        description: |
> +          Represents a thermistor sensor which is connected to one of the device
> +          channels.
> +
> +        properties:
> +          adi,sensor-type:
> +            description: |
> +              Identifies the type of thermistor connected to the
> +              device.
> +              19 - Thermistor 44004/44033 2.252kohm at 25°C
> +              20 - Thermistor 44005/44030 3kohm at 25°C
> +              21 - Thermistor 44007/44034 5kohm at 25°C
> +              22 - Thermistor 44006/44031 10kohm at 25°C
> +              23 - Thermistor 44008/44032 30kohm at 25°C
> +              24 - Thermistor YSI 400 2.252kohm at 25°C
> +              25 - Thermistor Spectrum 1003k 1kohm
> +              26 - Thermistor Custom Steinhart-Hart
> +              27 - Custom Thermistor
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32
> +              - minimum: 19
> +              - maximum: 27
> +
> +          adi,rsense-handle:
> +            description: |
> +              Phandle pointing to a rsense object associated with this
> +              thermistor.
> +            $ref: "/schemas/types.yaml#/definitions/phandle"
> +
> +          adi,single-ended:
> +            description: |
> +              Boolean property which set's the thermistor as single-ended.
> +            type: boolean
> +
> +          adi,rsense-share:
> +            description: |
> +              Boolean property which enables Rsense sharing, where one sense
> +              resistor is used for multiple thermistors. Note that this property
> +              is ignored if adi,single-ended is set.
> +            type: boolean
> +
> +          adi,current-rotate:
> +            description: |
> +              Boolean property which enables excitation current rotation to
> +              automatically remove parasitic thermocouple effects.
> +            type: boolean
> +
> +          adi,excitation-current-nanoamp:
> +            description: |
> +              This property controls the magnitude of the excitation current
> +              applied to the thermistor. Value 0 set's the sensor in auto-range
> +              mode.
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32
> +              - enum: [0, 250, 500, 1000, 5000, 10000, 25000, 50000, 100000,
> +                       250000, 500000, 1000000]
> +
> +          adi,custom-sensor:
> +            description: |
> +              This is a table, where each entry should be a pair of
> +              resistance(ohm)-temperature(K). The entries added here are in uohm
> +              and uK only for custom thermistors. For more details look at table
> +              78 and 79. Steinhart-Hart coefficients are also supported and can
> +              be programmed into the device memory using this property. For
> +              Steinhart sensors, this table has a constant size of 6 entries
> +              (defining the coefficients) and the values are given in the raw
> +              format. Look at table 82 for more information.
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint64-array
> +            minItems: 6
> +            maxItems: 128
> +
> +        required:
> +          - adi,sensor-type
> +          - adi,rsense-handle
> +
> +        dependencies:
> +          adi,current-rotate: [ adi,rsense-share ]
> +
> +      "^adc@.*":
> +        type: object
> +        description: Represents a channel which is being used as a direct adc.
> +
> +        properties:
> +          adi,sensor-type:
> +            description: Identifies the sensor as a direct adc.
> +            const: 30
> +
> +          adi,single-ended:
> +            description: Boolean property which set's the adc as single-ended.
> +            type: boolean
> +
> +        required:
> +          - adi,sensor-type
> +
> +      "^rsense@.*":
> +        type: object
> +        description: |
> +          Represents a rsense which is connected to one of the device channels.
> +          Rsense are used by thermistors and RTD's.
> +
> +        properties:
> +          reg:
> +            minimum: 2
> +
> +          adi,sensor-type:
> +            description: Identifies the sensor as a rsense.
> +            const: 29
> +
> +          adi,rsense-val-micro-ohms:
> +            description: |
> +              Sets the value of the sense resistor. Look at table 20 of the
> +              datasheet for information.
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint64
> +
> +        required:
> +          - adi,sensor-type
> +          - adi, rsense-val
> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    spi {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        sensor_ltc2983: ltc2983@0 {
> +                compatible = "adi,ltc2983";
> +                reg = <0>;
> +
> +                #address-cells = <1>;
> +                #size-cells = <0>;
> +
> +                adi,temperature-celcius;
> +                interrupts = <20 IRQ_TYPE_EDGE_RISING>;
> +                interrupt-parent = <&gpio>;
> +
> +                thermocouple@18 {
> +                        reg = <18>;
> +                        adi,sensor-type = <8>; //Type B
> +                        adi,sensor-oc-current-microamp = <10>;
> +                        adi,cold-junction-handle = <&diode5>;
> +                };
> +
> +                diode5: diode@5 {
> +                        reg = <5>;
> +                        adi,sensor-type = <28>;
> +                };
> +
> +                rsense2: rsense@2 {
> +                        reg = <2>;
> +                        adi,sensor-type = <29>;
> +                        adi,rsense-val-micro-ohms = /bits/ 64 <1200000000>; //1.2Kohms
> +                };
> +
> +                rtd@14 {
> +                        reg = <14>;
> +                        adi,sensor-type = <15>; //PT1000
> +                        /*2-wire, internal gnd, no current rotation*/
> +                        adi,number-of-wires = <2>;
> +                        adi,rsense-share;
> +                        adi,excitation-current-microamp = <500>;
> +                        adi,rsense-handle = <&rsense2>;
> +                };
> +
> +                adc@10 {
> +                        reg = <10>;
> +                        adi,sensor-type = <30>;
> +                        adi,single-ended;
> +                };
> +
> +                thermistor@12 {
> +                        reg = <12>;
> +                        adi,sensor-type = <26>; //Steinhart
> +                        adi,rsense-handle = <&rsense2>;
> +                        adi,custom-sensor = /bits/ 64 <0x00F371EC 0x12345678
> +                                        0x2C0F8733 0x10018C66 0xA0FEACCD
> +                                        0x90021D99>; //6 entries
> +                };
> +
> +                thermocouple@20 {
> +                        reg = <20>;
> +                        adi,sensor-type = <9>; //custom thermocouple
> +                        adi,single-ended;
> +                        adi,custom-sensor = /bits/ 64
> +                                 <(-50220000) 0
> +                                  (-30200000) 99100000
> +                                  (-5300000) 135400000
> +                                  0 273150000
> +                                  40200000 361200000
> +                                  55300000 522100000
> +                                  88300000 720300000
> +                                  132200000 811200000
> +                                  188700000 922500000
> +                                  460400000 1000000000>; //10 pairs
> +               };
> +
> +        };
> +    };
> +...
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 14a256e785ca..f747a9dc27f5 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -9497,6 +9497,7 @@ W:	http://ez.analog.com/community/linux-device-drivers
>  L:	linux-iio@vger.kernel.org
>  S:	Supported
>  F:	drivers/iio/temperature/ltc2983.c
> +F:	Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
>  
>  LTC4261 HARDWARE MONITOR DRIVER
>  M:	Guenter Roeck <linux@roeck-us.net>
Rob Herring Oct. 7, 2019, 2:45 p.m. UTC | #2
On Fri, Oct 4, 2019 at 8:55 AM Nuno Sá <nuno.sa@analog.com> wrote:
>
> Document the LTC2983 temperature sensor devicetree bindings.
>
> Signed-off-by: Nuno Sá <nuno.sa@analog.com>
> ---
> Changes in v2:
>  * Drop maxItems in non-array elements;
>  * Set adi,mux-delay-config-us instead of adi,mux-delay-config;
>  * Wrapped lines at 80 char;
>  * Added comas to enum elements;
>  * Use real units in adi,excitation-current;
>  * Moved some enums to minimum and maximum;
>  * Grouped patternProperties and moved reg property as a generic property.
>
> Changes in v3:
>  * Add meaning to adi,sensor-type values which are not const;
>  * Add meaning to adi,filter-notch-freq values;
>  * Break up adi,sensor-config into human readable elements;
>  * Set maxItems/minItems at the same identation as allOf in adi,custom-sensor;
>  * Fixed the maximum value for adi,sensor-type for sensors with custom support;
>  * Changed license to GPL-2.0-only as it should be for new bindings;
>  * Changed spi0 to spi in the dts example;
>  * Updated the dts example to the new properties.
>
>  .../bindings/iio/temperature/adi,ltc2983.yaml | 479 ++++++++++++++++++
>  MAINTAINERS                                   |   1 +
>  2 files changed, 480 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
>
> diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> new file mode 100644
> index 000000000000..b7101a0e84db
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> @@ -0,0 +1,479 @@
> +# SPDX-License-Identifier: GPL-2.0-only

(GPL-2.0-only OR BSD-2-Clause) for new bindings please.

> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/temperature/adi,ltc2983.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Analog Devices LTC2983 Multi-sensor Temperature system
> +
> +maintainers:
> +  - Nuno Sá <nuno.sa@analog.com>
> +
> +description: |
> +  Analog Devices LTC2983 Multi-Sensor Digital Temperature Measurement System
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/2983fc.pdf
> +
> +properties:
> +  compatible:
> +    enum:
> +      - adi,ltc2983
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  adi,temperature-celcius:

-celsius. However, that suffix is reserved for properties whose value
is in Celsius, so you'll have to come up with something else.

How does one decide how to set this? Seems like the driver should just
decide based on what it needs to present to the user.

> +    description:
> +      If this property is present, the temperature is reported in Celsius.
> +    type: boolean
> +
> +  adi,mux-delay-config-us:
> +    description:
> +      The LTC2983 performs 2 or 3 internal conversion cycles per temperature
> +      result. Each conversion cycle is performed with different excitation and
> +      input multiplexer configurations. Prior to each conversion, these
> +      excitation circuits and input switch configurations are changed and an
> +      internal 1ms delay ensures settling prior to the conversion cycle in most
> +      cases. An extra delay can be configured using this property. The value is
> +      rounded to nearest 100us.
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +      - maximum: 255

Standard unit suffixes already have a type, so just:

maximum: 255

> +
> +  adi,filter-notch-freq:
> +    description:
> +      Set's the default setting of the digital filter. The default is
> +      simultaneous 50/60Hz rejection.
> +      0 - 50/60Hz rejection
> +      1 - 60Hz rejection
> +      2 - 50Hz rejection
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +      - minimum: 0
> +      - maximum: 2

Drop the '-' on the last entry (making the min/max a single schema).

> +
> +  '#address-cells':
> +    const: 1
> +
> +  '#size-cells':
> +    const: 0
> +
> +patternProperties:
> +  ".*@([1-9]|1[0-9]|20)$":

'.*' can be dropped.

> +    type: object
> +
> +    properties:
> +      reg:
> +        description: |
> +          The channel number. It can be connected to one of the 20 channels of
> +          the device.
> +        minimum: 1
> +        maximum: 20
> +
> +    required:
> +      - reg
> +
> +    patternProperties:
> +      "^thermocouple@.*":

You've made this node a child of '.*@([1-9]|1[0-9]|20)$'. This needs
to be at the same level.

> +        type: object
> +        description: |

You can drop the '|' where you don't need any formatting.

> +          Represents a thermocouple sensor which is connected to one of the device
> +          channels.
> +
> +        properties:
> +          adi,sensor-type:
> +            description: |
> +              Identifies the type of thermocouple connected to the device.
> +              1 - Type J Thermocouple
> +              2 - Type K Thermocouple
> +              3 - Type E Thermocouple
> +              4 - Type N Thermocouple
> +              5 - Type R Thermocouple
> +              6 - Type S Thermocouple
> +              7 - Type T Thermocouple
> +              8 - Type B Thermocouple
> +              9 - Custom Thermocouple
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32

You can move the type definition under ".*@([1-9]|1[0-9]|20)$" and
then just have the min/max here.

> +              - minimum: 1
> +              - maximum: 9
> +
> +          adi,single-ended:
> +            description: |
> +              Boolean property which set's the thermocouple as single-ended.
> +            type: boolean
> +
> +          adi,sensor-oc-current-microamp:
> +            description: |
> +              This property set's the pulsed current value applied during
> +              open-circuit detect.
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32
> +              - enum: [10, 100, 500, 1000]
> +
> +          adi,cold-junction-handle:
> +            description: |
> +              Phandle which points to a sensor object responsible for measuring
> +              the thermocouple cold junction temperature.
> +            $ref: "/schemas/types.yaml#/definitions/phandle"
> +
> +          adi,custom-sensor:
> +            description: |
> +              This is a table, where each entry should be a pair of
> +              voltage(mv)-temperature(K). The entries must be given in nv and uK
> +              so that, the original values must be multiplied by 1000000. For

We normally do things in microVolts. It seems strange to need 64-bits
of range for voltage and temperature.

> +              more details look at table 69 and 70.
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/int64-array

Fails on 'make dt_binding_check':

Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml:
Unresolvable JSON pointer: 'definitions/int64-array'

If this is pairs of values, it should really be defined as a matrix:

minItems: 3
maxItems: 64
items:
  minItems: 2
  maxItems: 2

Though I'll need to add uint64-matrix as a type (assuming this really
needs to be 64-bit).


> +            minItems: 6
> +            maxItems: 128
> +
> +        required:
> +          - adi,sensor-type
> +
> +      "^diode@.*":
> +        type: object
> +        description: |
> +          Represents a diode sensor which is connected to one of the device
> +          channels.
> +
> +        properties:
> +          adi,sensor-type:
> +            description: Identifies the sensor as a diode.
> +            const: 28
> +
> +          adi,single-ended:
> +            description: Boolean property which set's the diode as single-ended.
> +            type: boolean
> +
> +          adi,three-conversion-cycles:
> +            description: |
> +              Boolean property which set's three conversion cycles removing
> +              parasitic resistance effects between the LTC2983 and the diode.
> +            type: boolean
> +
> +          adi,average-on:
> +            description: |
> +              Boolean property which enables a running average of the diode
> +              temperature reading. This reduces the noise when the diode is used
> +              as a cold junction temperature element on an isothermal block
> +              where temperatures change slowly.
> +            type: boolean
> +
> +          adi,excitation-current-microamp:
> +            description: |
> +              This property controls the magnitude of the excitation current
> +              applied to the diode. Depending on the number of conversions
> +              cycles, this property will assume different predefined values on
> +              each cycle. Just set the value of the first cycle (1l).
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32
> +              - enum: [10, 20, 40, 80]
> +
> +          adi,ideal-factor-value:
> +            description: |
> +              This property sets the diode ideality factor. The real value must
> +              be multiplied by 1000000 to remove the fractional part. For more
> +              information look at table 20 of the datasheet.
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32
> +
> +        required:
> +          - adi,sensor-type
> +
> +      "^rtd@.*":
> +        type: object
> +        description: |
> +          Represents a rtd sensor which is connected to one of the device channels.
> +
> +        properties:
> +          reg:
> +            minimum: 2
> +
> +          adi,sensor-type:
> +            description: |
> +              Identifies the type of RTD connected to the device.
> +              10 - RTD PT-10
> +              11 - RTD PT-50
> +              12 - RTD PT-100
> +              13 - RTD PT-200
> +              14 - RTD PT-500
> +              15 - RTD PT-1000
> +              16 - RTD PT-1000 (0.00375)
> +              17 - RTD NI-120
> +              18 - RTD Custom
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32
> +              - minimum: 10
> +              - maximum: 18
> +
> +          adi,rsense-handle:
> +            description: |
> +              Phandle pointing to a rsense object associated with this RTD.
> +            $ref: "/schemas/types.yaml#/definitions/phandle"
> +
> +          adi,number-of-wires:
> +            description: |
> +              Identifies the number of wires used by the RTD. Setting this
> +              property to 5 means 4 wires with Kelvin Rsense.
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32
> +              - enum: [2, 3, 4, 5]
> +
> +          adi,rsense-share:
> +            description: |
> +              Boolean property which enables Rsense sharing, where one sense
> +              resistor is used for multiple 2-, 3-, and/or 4-wire RTDs.
> +            type: boolean
> +
> +          adi,current-rotate:
> +            description: |
> +              Boolean property which enables excitation current rotation to
> +              automatically remove parasitic thermocouple effects. Note that
> +              this property is not allowed for 2- and 3-wire RTDs.
> +            type: boolean
> +
> +          adi,excitation-current-microamp:
> +            description: |
> +              This property controls the magnitude of the excitation current
> +              applied to the RTD.
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32

You can drop the type here too.

> +              - enum: [5, 10, 25, 50, 100, 250, 500, 1000]
> +
> +          adi,rtd-curve:
> +            description: |
> +              This property set the RTD curve used and the corresponding
> +              Callendar-VanDusen constants. Look at table 30 of the datasheet.
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32
> +              - minimum: 0
> +              - maximum: 3
> +
> +          adi,custom-sensor:
> +            description: |
> +              This is a table, where each entry should be a pair of
> +              resistance(ohm)-temperature(K). The entries added here are in uohm
> +              and uK. For more details values look at table 74 and 75.

It's not great to make one property name have different meanings.

> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint64-array
> +            minItems: 6
> +            maxItems: 128
> +
> +        required:
> +          - adi,sensor-type
> +          - adi,rsense-handle
> +
> +        dependencies:
> +          adi,current-rotate: [ adi,rsense-share ]
> +
> +      "^thermistor@.*":
> +        type: object
> +        description: |
> +          Represents a thermistor sensor which is connected to one of the device
> +          channels.
> +
> +        properties:
> +          adi,sensor-type:
> +            description: |
> +              Identifies the type of thermistor connected to the
> +              device.
> +              19 - Thermistor 44004/44033 2.252kohm at 25°C
> +              20 - Thermistor 44005/44030 3kohm at 25°C
> +              21 - Thermistor 44007/44034 5kohm at 25°C
> +              22 - Thermistor 44006/44031 10kohm at 25°C
> +              23 - Thermistor 44008/44032 30kohm at 25°C
> +              24 - Thermistor YSI 400 2.252kohm at 25°C
> +              25 - Thermistor Spectrum 1003k 1kohm
> +              26 - Thermistor Custom Steinhart-Hart
> +              27 - Custom Thermistor
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32
> +              - minimum: 19
> +              - maximum: 27
> +
> +          adi,rsense-handle:
> +            description: |
> +              Phandle pointing to a rsense object associated with this
> +              thermistor.
> +            $ref: "/schemas/types.yaml#/definitions/phandle"
> +
> +          adi,single-ended:
> +            description: |
> +              Boolean property which set's the thermistor as single-ended.
> +            type: boolean
> +
> +          adi,rsense-share:
> +            description: |
> +              Boolean property which enables Rsense sharing, where one sense
> +              resistor is used for multiple thermistors. Note that this property
> +              is ignored if adi,single-ended is set.
> +            type: boolean
> +
> +          adi,current-rotate:
> +            description: |
> +              Boolean property which enables excitation current rotation to
> +              automatically remove parasitic thermocouple effects.
> +            type: boolean
> +
> +          adi,excitation-current-nanoamp:
> +            description: |
> +              This property controls the magnitude of the excitation current
> +              applied to the thermistor. Value 0 set's the sensor in auto-range
> +              mode.
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32
> +              - enum: [0, 250, 500, 1000, 5000, 10000, 25000, 50000, 100000,
> +                       250000, 500000, 1000000]
> +
> +          adi,custom-sensor:
> +            description: |
> +              This is a table, where each entry should be a pair of
> +              resistance(ohm)-temperature(K). The entries added here are in uohm
> +              and uK only for custom thermistors. For more details look at table
> +              78 and 79. Steinhart-Hart coefficients are also supported and can
> +              be programmed into the device memory using this property. For
> +              Steinhart sensors, this table has a constant size of 6 entries
> +              (defining the coefficients) and the values are given in the raw
> +              format. Look at table 82 for more information.
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint64-array
> +            minItems: 6
> +            maxItems: 128
> +
> +        required:
> +          - adi,sensor-type
> +          - adi,rsense-handle
> +
> +        dependencies:
> +          adi,current-rotate: [ adi,rsense-share ]
> +
> +      "^adc@.*":
> +        type: object
> +        description: Represents a channel which is being used as a direct adc.
> +
> +        properties:
> +          adi,sensor-type:
> +            description: Identifies the sensor as a direct adc.
> +            const: 30
> +
> +          adi,single-ended:
> +            description: Boolean property which set's the adc as single-ended.
> +            type: boolean
> +
> +        required:
> +          - adi,sensor-type
> +
> +      "^rsense@.*":
> +        type: object
> +        description: |
> +          Represents a rsense which is connected to one of the device channels.
> +          Rsense are used by thermistors and RTD's.
> +
> +        properties:
> +          reg:
> +            minimum: 2
> +
> +          adi,sensor-type:
> +            description: Identifies the sensor as a rsense.
> +            const: 29
> +
> +          adi,rsense-val-micro-ohms:
> +            description: |
> +              Sets the value of the sense resistor. Look at table 20 of the
> +              datasheet for information.
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint64

-micro-ohms is already defined to be 32-bit.

> +
> +        required:
> +          - adi,sensor-type
> +          - adi, rsense-val

spurious space.

> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    spi {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        sensor_ltc2983: ltc2983@0 {
> +                compatible = "adi,ltc2983";
> +                reg = <0>;
> +
> +                #address-cells = <1>;
> +                #size-cells = <0>;
> +
> +                adi,temperature-celcius;
> +                interrupts = <20 IRQ_TYPE_EDGE_RISING>;
> +                interrupt-parent = <&gpio>;
> +
> +                thermocouple@18 {
> +                        reg = <18>;
> +                        adi,sensor-type = <8>; //Type B
> +                        adi,sensor-oc-current-microamp = <10>;
> +                        adi,cold-junction-handle = <&diode5>;
> +                };
> +
> +                diode5: diode@5 {
> +                        reg = <5>;
> +                        adi,sensor-type = <28>;
> +                };
> +
> +                rsense2: rsense@2 {
> +                        reg = <2>;
> +                        adi,sensor-type = <29>;
> +                        adi,rsense-val-micro-ohms = /bits/ 64 <1200000000>; //1.2Kohms
> +                };
> +
> +                rtd@14 {
> +                        reg = <14>;
> +                        adi,sensor-type = <15>; //PT1000
> +                        /*2-wire, internal gnd, no current rotation*/
> +                        adi,number-of-wires = <2>;
> +                        adi,rsense-share;
> +                        adi,excitation-current-microamp = <500>;
> +                        adi,rsense-handle = <&rsense2>;
> +                };
> +
> +                adc@10 {
> +                        reg = <10>;
> +                        adi,sensor-type = <30>;
> +                        adi,single-ended;
> +                };
> +
> +                thermistor@12 {
> +                        reg = <12>;
> +                        adi,sensor-type = <26>; //Steinhart
> +                        adi,rsense-handle = <&rsense2>;
> +                        adi,custom-sensor = /bits/ 64 <0x00F371EC 0x12345678
> +                                        0x2C0F8733 0x10018C66 0xA0FEACCD
> +                                        0x90021D99>; //6 entries
> +                };
> +
> +                thermocouple@20 {
> +                        reg = <20>;
> +                        adi,sensor-type = <9>; //custom thermocouple
> +                        adi,single-ended;
> +                        adi,custom-sensor = /bits/ 64
> +                                 <(-50220000) 0
> +                                  (-30200000) 99100000
> +                                  (-5300000) 135400000
> +                                  0 273150000
> +                                  40200000 361200000
> +                                  55300000 522100000
> +                                  88300000 720300000
> +                                  132200000 811200000
> +                                  188700000 922500000
> +                                  460400000 1000000000>; //10 pairs
> +               };
> +
> +        };
> +    };
> +...
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 14a256e785ca..f747a9dc27f5 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -9497,6 +9497,7 @@ W:        http://ez.analog.com/community/linux-device-drivers
>  L:     linux-iio@vger.kernel.org
>  S:     Supported
>  F:     drivers/iio/temperature/ltc2983.c
> +F:     Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
>
>  LTC4261 HARDWARE MONITOR DRIVER
>  M:     Guenter Roeck <linux@roeck-us.net>
> --
> 2.23.0
>
Nuno Sa Oct. 7, 2019, 4:17 p.m. UTC | #3
On Mon, 2019-10-07 at 09:45 -0500, Rob Herring wrote:
> On Fri, Oct 4, 2019 at 8:55 AM Nuno Sá <nuno.sa@analog.com> wrote:
> > Document the LTC2983 temperature sensor devicetree bindings.
> > 
> > Signed-off-by: Nuno Sá <nuno.sa@analog.com>
> > ---
> > Changes in v2:
> >  * Drop maxItems in non-array elements;
> >  * Set adi,mux-delay-config-us instead of adi,mux-delay-config;
> >  * Wrapped lines at 80 char;
> >  * Added comas to enum elements;
> >  * Use real units in adi,excitation-current;
> >  * Moved some enums to minimum and maximum;
> >  * Grouped patternProperties and moved reg property as a generic
> > property.
> > 
> > Changes in v3:
> >  * Add meaning to adi,sensor-type values which are not const;
> >  * Add meaning to adi,filter-notch-freq values;
> >  * Break up adi,sensor-config into human readable elements;
> >  * Set maxItems/minItems at the same identation as allOf in
> > adi,custom-sensor;
> >  * Fixed the maximum value for adi,sensor-type for sensors with
> > custom support;
> >  * Changed license to GPL-2.0-only as it should be for new
> > bindings;
> >  * Changed spi0 to spi in the dts example;
> >  * Updated the dts example to the new properties.
> > 
> >  .../bindings/iio/temperature/adi,ltc2983.yaml | 479
> > ++++++++++++++++++
> >  MAINTAINERS                                   |   1 +
> >  2 files changed, 480 insertions(+)
> >  create mode 100644
> > Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> > 
> > diff --git
> > a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > l
> > b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > l
> > new file mode 100644
> > index 000000000000..b7101a0e84db
> > --- /dev/null
> > +++
> > b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > l
> > @@ -0,0 +1,479 @@
> > +# SPDX-License-Identifier: GPL-2.0-only
> 
> (GPL-2.0-only OR BSD-2-Clause) for new bindings please.

ack.

> > +%YAML 1.2
> > +---
> > +$id: 
> > http://devicetree.org/schemas/iio/temperature/adi,ltc2983.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Analog Devices LTC2983 Multi-sensor Temperature system
> > +
> > +maintainers:
> > +  - Nuno Sá <nuno.sa@analog.com>
> > +
> > +description: |
> > +  Analog Devices LTC2983 Multi-Sensor Digital Temperature
> > Measurement System
> > +  
> > https://www.analog.com/media/en/technical-documentation/data-sheets/2983fc.pdf
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - adi,ltc2983
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +
> > +  adi,temperature-celcius:
> 
> -celsius. However, that suffix is reserved for properties whose value
> is in Celsius, so you'll have to come up with something else.
> 
> How does one decide how to set this? Seems like the driver should
> just
> decide based on what it needs to present to the user.

The device can report temperature in Celsius or Fahrenheit and that
should be decided once. Hmm but now that I think about this, the iio
standard attributes expect the value to be reported in milli degrees
Celsius so I guess I should just drop this and don't report in
Fahrenheit. Would this be ok Jonathan?

> > +    description:
> > +      If this property is present, the temperature is reported in
> > Celsius.
> > +    type: boolean
> > +
> > +  adi,mux-delay-config-us:
> > +    description:
> > +      The LTC2983 performs 2 or 3 internal conversion cycles per
> > temperature
> > +      result. Each conversion cycle is performed with different
> > excitation and
> > +      input multiplexer configurations. Prior to each conversion,
> > these
> > +      excitation circuits and input switch configurations are
> > changed and an
> > +      internal 1ms delay ensures settling prior to the conversion
> > cycle in most
> > +      cases. An extra delay can be configured using this property.
> > The value is
> > +      rounded to nearest 100us.
> > +    allOf:
> > +      - $ref: /schemas/types.yaml#/definitions/uint32
> > +      - maximum: 255
> 
> Standard unit suffixes already have a type, so just:
> 
> maximum: 255

got it.

> > +
> > +  adi,filter-notch-freq:
> > +    description:
> > +      Set's the default setting of the digital filter. The default
> > is
> > +      simultaneous 50/60Hz rejection.
> > +      0 - 50/60Hz rejection
> > +      1 - 60Hz rejection
> > +      2 - 50Hz rejection
> > +    allOf:
> > +      - $ref: /schemas/types.yaml#/definitions/uint32
> > +      - minimum: 0
> > +      - maximum: 2
> 
> Drop the '-' on the last entry (making the min/max a single schema).

got it.

> > +
> > +  '#address-cells':
> > +    const: 1
> > +
> > +  '#size-cells':
> > +    const: 0
> > +
> > +patternProperties:
> > +  ".*@([1-9]|1[0-9]|20)$":
> 
> '.*' can be dropped.
> 
> > +    type: object
> > +
> > +    properties:
> > +      reg:
> > +        description: |
> > +          The channel number. It can be connected to one of the 20
> > channels of
> > +          the device.
> > +        minimum: 1
> > +        maximum: 20
> > +
> > +    required:
> > +      - reg
> > +
> > +    patternProperties:
> > +      "^thermocouple@.*":
> 
> You've made this node a child of '.*@([1-9]|1[0-9]|20)$'. This needs
> to be at the same level.

You mean dropping "patternProperties" and having "^thermocouple@.*": on
the same indent as ".*@([1-9]|1[0-9]|20)$":? It seems to be only one
working. I understood and tried something like:

patternProperties:
  "@([1-9]|1[0-9]|20)$":
   (...)
   
   patternProperties:
     "^thermocouple@.*"
     description: "..."
     type: object
     properties:
     (...)

But this throws "'^thermocouple@' is not one of ['$ref',
'additionalItems', 'additionalProperties', 'allOf', 'anyOf', 'const',
'contains', 'default', 'dependencies', 'deprecated', 'description',
'else', 'enum', 'items', 'if', 'minItems', 'minimum', 'maxItems',
'maximum', 'not', 'oneOf', 'pattern', 'patternProperties',
'properties', 'required', 'then', 'type', 'typeSize']"

Also, should I also drop the ".*" in "^thermocouple@.*"?
> > +        type: object
> > +        description: |
> 
> You can drop the '|' where you don't need any formatting.

got it.

> > +          Represents a thermocouple sensor which is connected to
> > one of the device
> > +          channels.
> > +
> > +        properties:
> > +          adi,sensor-type:
> > +            description: |
> > +              Identifies the type of thermocouple connected to the
> > device.
> > +              1 - Type J Thermocouple
> > +              2 - Type K Thermocouple
> > +              3 - Type E Thermocouple
> > +              4 - Type N Thermocouple
> > +              5 - Type R Thermocouple
> > +              6 - Type S Thermocouple
> > +              7 - Type T Thermocouple
> > +              8 - Type B Thermocouple
> > +              9 - Custom Thermocouple
> > +            allOf:
> > +              - $ref: /schemas/types.yaml#/definitions/uint32
> 
> You can move the type definition under ".*@([1-9]|1[0-9]|20)$" and
> then just have the min/max here.

And how could I add meaning to the values. Could I add all in the
"parent" node?

> > +              - minimum: 1
> > +              - maximum: 9
> > +
> > +          adi,single-ended:
> > +            description: |
> > +              Boolean property which set's the thermocouple as
> > single-ended.
> > +            type: boolean
> > +
> > +          adi,sensor-oc-current-microamp:
> > +            description: |
> > +              This property set's the pulsed current value applied
> > during
> > +              open-circuit detect.
> > +            allOf:
> > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > +              - enum: [10, 100, 500, 1000]
> > +
> > +          adi,cold-junction-handle:
> > +            description: |
> > +              Phandle which points to a sensor object responsible
> > for measuring
> > +              the thermocouple cold junction temperature.
> > +            $ref: "/schemas/types.yaml#/definitions/phandle"
> > +
> > +          adi,custom-sensor:
> > +            description: |
> > +              This is a table, where each entry should be a pair
> > of
> > +              voltage(mv)-temperature(K). The entries must be
> > given in nv and uK
> > +              so that, the original values must be multiplied by
> > 1000000. For
> 
> We normally do things in microVolts. It seems strange to need 64-bits
> of range for voltage and temperature.

This device support very high resolutions (so we have fractional
values). That is why I'm multiplying by 1000000 and using nV. And even
so, I already loose some bits. The 64bits are needed mainly because of
the Temperature and again the resolution I want to maximize. Doing
int(max(temp)) * 1000000, we need 64bits.

> 
> > +              more details look at table 69 and 70.
> > +            allOf:
> > +              - $ref: /schemas/types.yaml#/definitions/int64-array
> 
> Fails on 'make dt_binding_check':
> 
> Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml:
> Unresolvable JSON pointer: 'definitions/int64-array'

I was aware of this but I do not know how to proceed so I was waiting
for your comment. I do have negative values, so uint does not apply.
What can I use here?

> If this is pairs of values, it should really be defined as a matrix:
> 
> minItems: 3
> maxItems: 64
> items:
>   minItems: 2
>   maxItems: 2
> 
> Though I'll need to add uint64-matrix as a type (assuming this really
> needs to be 64-bit).

I reinforce that I do need signed values here.

> 
> > +            minItems: 6
> > +            maxItems: 128
> > +
> > +        required:
> > +          - adi,sensor-type
> > +
> > +      "^diode@.*":
> > +        type: object
> > +        description: |
> > +          Represents a diode sensor which is connected to one of
> > the device
> > +          channels.
> > +
> > +        properties:
> > +          adi,sensor-type:
> > +            description: Identifies the sensor as a diode.
> > +            const: 28
> > +
> > +          adi,single-ended:
> > +            description: Boolean property which set's the diode as
> > single-ended.
> > +            type: boolean
> > +
> > +          adi,three-conversion-cycles:
> > +            description: |
> > +              Boolean property which set's three conversion cycles
> > removing
> > +              parasitic resistance effects between the LTC2983 and
> > the diode.
> > +            type: boolean
> > +
> > +          adi,average-on:
> > +            description: |
> > +              Boolean property which enables a running average of
> > the diode
> > +              temperature reading. This reduces the noise when the
> > diode is used
> > +              as a cold junction temperature element on an
> > isothermal block
> > +              where temperatures change slowly.
> > +            type: boolean
> > +
> > +          adi,excitation-current-microamp:
> > +            description: |
> > +              This property controls the magnitude of the
> > excitation current
> > +              applied to the diode. Depending on the number of
> > conversions
> > +              cycles, this property will assume different
> > predefined values on
> > +              each cycle. Just set the value of the first cycle
> > (1l).
> > +            allOf:
> > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > +              - enum: [10, 20, 40, 80]
> > +
> > +          adi,ideal-factor-value:
> > +            description: |
> > +              This property sets the diode ideality factor. The
> > real value must
> > +              be multiplied by 1000000 to remove the fractional
> > part. For more
> > +              information look at table 20 of the datasheet.
> > +            allOf:
> > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > +
> > +        required:
> > +          - adi,sensor-type
> > +
> > +      "^rtd@.*":
> > +        type: object
> > +        description: |
> > +          Represents a rtd sensor which is connected to one of the
> > device channels.
> > +
> > +        properties:
> > +          reg:
> > +            minimum: 2
> > +
> > +          adi,sensor-type:
> > +            description: |
> > +              Identifies the type of RTD connected to the device.
> > +              10 - RTD PT-10
> > +              11 - RTD PT-50
> > +              12 - RTD PT-100
> > +              13 - RTD PT-200
> > +              14 - RTD PT-500
> > +              15 - RTD PT-1000
> > +              16 - RTD PT-1000 (0.00375)
> > +              17 - RTD NI-120
> > +              18 - RTD Custom
> > +            allOf:
> > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > +              - minimum: 10
> > +              - maximum: 18
> > +
> > +          adi,rsense-handle:
> > +            description: |
> > +              Phandle pointing to a rsense object associated with
> > this RTD.
> > +            $ref: "/schemas/types.yaml#/definitions/phandle"
> > +
> > +          adi,number-of-wires:
> > +            description: |
> > +              Identifies the number of wires used by the RTD.
> > Setting this
> > +              property to 5 means 4 wires with Kelvin Rsense.
> > +            allOf:
> > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > +              - enum: [2, 3, 4, 5]
> > +
> > +          adi,rsense-share:
> > +            description: |
> > +              Boolean property which enables Rsense sharing, where
> > one sense
> > +              resistor is used for multiple 2-, 3-, and/or 4-wire
> > RTDs.
> > +            type: boolean
> > +
> > +          adi,current-rotate:
> > +            description: |
> > +              Boolean property which enables excitation current
> > rotation to
> > +              automatically remove parasitic thermocouple effects.
> > Note that
> > +              this property is not allowed for 2- and 3-wire RTDs.
> > +            type: boolean
> > +
> > +          adi,excitation-current-microamp:
> > +            description: |
> > +              This property controls the magnitude of the
> > excitation current
> > +              applied to the RTD.
> > +            allOf:
> > +              - $ref: /schemas/types.yaml#/definitions/uint32
> 
> You can drop the type here too.

got it.

> > +              - enum: [5, 10, 25, 50, 100, 250, 500, 1000]
> > +
> > +          adi,rtd-curve:
> > +            description: |
> > +              This property set the RTD curve used and the
> > corresponding
> > +              Callendar-VanDusen constants. Look at table 30 of
> > the datasheet.
> > +            allOf:
> > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > +              - minimum: 0
> > +              - maximum: 3
> > +
> > +          adi,custom-sensor:
> > +            description: |
> > +              This is a table, where each entry should be a pair
> > of
> > +              resistance(ohm)-temperature(K). The entries added
> > here are in uohm
> > +              and uK. For more details values look at table 74 and
> > 75.
> 
> It's not great to make one property name have different meanings.

Would you prefer to have something like "custom-rtd", "custom-
thermoucouple" and so on? I would have to adapt the code but I don't
think it would need to much of a change.

> > +            allOf:
> > +              - $ref: /schemas/types.yaml#/definitions/uint64-
> > array
> > +            minItems: 6
> > +            maxItems: 128
> > +
> > +        required:
> > +          - adi,sensor-type
> > +          - adi,rsense-handle
> > +
> > +        dependencies:
> > +          adi,current-rotate: [ adi,rsense-share ]
> > +
> > +      "^thermistor@.*":
> > +        type: object
> > +        description: |
> > +          Represents a thermistor sensor which is connected to one
> > of the device
> > +          channels.
> > +
> > +        properties:
> > +          adi,sensor-type:
> > +            description: |
> > +              Identifies the type of thermistor connected to the
> > +              device.
> > +              19 - Thermistor 44004/44033 2.252kohm at 25°C
> > +              20 - Thermistor 44005/44030 3kohm at 25°C
> > +              21 - Thermistor 44007/44034 5kohm at 25°C
> > +              22 - Thermistor 44006/44031 10kohm at 25°C
> > +              23 - Thermistor 44008/44032 30kohm at 25°C
> > +              24 - Thermistor YSI 400 2.252kohm at 25°C
> > +              25 - Thermistor Spectrum 1003k 1kohm
> > +              26 - Thermistor Custom Steinhart-Hart
> > +              27 - Custom Thermistor
> > +            allOf:
> > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > +              - minimum: 19
> > +              - maximum: 27
> > +
> > +          adi,rsense-handle:
> > +            description: |
> > +              Phandle pointing to a rsense object associated with
> > this
> > +              thermistor.
> > +            $ref: "/schemas/types.yaml#/definitions/phandle"
> > +
> > +          adi,single-ended:
> > +            description: |
> > +              Boolean property which set's the thermistor as
> > single-ended.
> > +            type: boolean
> > +
> > +          adi,rsense-share:
> > +            description: |
> > +              Boolean property which enables Rsense sharing, where
> > one sense
> > +              resistor is used for multiple thermistors. Note that
> > this property
> > +              is ignored if adi,single-ended is set.
> > +            type: boolean
> > +
> > +          adi,current-rotate:
> > +            description: |
> > +              Boolean property which enables excitation current
> > rotation to
> > +              automatically remove parasitic thermocouple effects.
> > +            type: boolean
> > +
> > +          adi,excitation-current-nanoamp:
> > +            description: |
> > +              This property controls the magnitude of the
> > excitation current
> > +              applied to the thermistor. Value 0 set's the sensor
> > in auto-range
> > +              mode.
> > +            allOf:
> > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > +              - enum: [0, 250, 500, 1000, 5000, 10000, 25000,
> > 50000, 100000,
> > +                       250000, 500000, 1000000]
> > +
> > +          adi,custom-sensor:
> > +            description: |
> > +              This is a table, where each entry should be a pair
> > of
> > +              resistance(ohm)-temperature(K). The entries added
> > here are in uohm
> > +              and uK only for custom thermistors. For more details
> > look at table
> > +              78 and 79. Steinhart-Hart coefficients are also
> > supported and can
> > +              be programmed into the device memory using this
> > property. For
> > +              Steinhart sensors, this table has a constant size of
> > 6 entries
> > +              (defining the coefficients) and the values are given
> > in the raw
> > +              format. Look at table 82 for more information.
> > +            allOf:
> > +              - $ref: /schemas/types.yaml#/definitions/uint64-
> > array
> > +            minItems: 6
> > +            maxItems: 128
> > +

If I'm to replace this property as proposed before, would it make sense
also to split this in custom-thermistor and custom-steinhart or just
steinhart?

> > +        required:
> > +          - adi,sensor-type
> > +          - adi,rsense-handle
> > +
> > +        dependencies:
> > +          adi,current-rotate: [ adi,rsense-share ]
> > +
> > +      "^adc@.*":
> > +        type: object
> > +        description: Represents a channel which is being used as a
> > direct adc.
> > +
> > +        properties:
> > +          adi,sensor-type:
> > +            description: Identifies the sensor as a direct adc.
> > +            const: 30
> > +
> > +          adi,single-ended:
> > +            description: Boolean property which set's the adc as
> > single-ended.
> > +            type: boolean
> > +
> > +        required:
> > +          - adi,sensor-type
> > +
> > +      "^rsense@.*":
> > +        type: object
> > +        description: |
> > +          Represents a rsense which is connected to one of the
> > device channels.
> > +          Rsense are used by thermistors and RTD's.
> > +
> > +        properties:
> > +          reg:
> > +            minimum: 2
> > +
> > +          adi,sensor-type:
> > +            description: Identifies the sensor as a rsense.
> > +            const: 29
> > +
> > +          adi,rsense-val-micro-ohms:
> > +            description: |
> > +              Sets the value of the sense resistor. Look at table
> > 20 of the
> > +              datasheet for information.
> > +            allOf:
> > +              - $ref: /schemas/types.yaml#/definitions/uint64
> 
> -micro-ohms is already defined to be 32-bit.
 
I do need a 64-bit variable here. Should I still remove the $ref or how
can I proceed?

> > +
> > +        required:
> > +          - adi,sensor-type
> > +          - adi, rsense-val
> 
> spurious space.

got it.

> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - interrupts
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/interrupt-controller/irq.h>
> > +    spi {
> > +        #address-cells = <1>;
> > +        #size-cells = <0>;
> > +
> > +        sensor_ltc2983: ltc2983@0 {
> > +                compatible = "adi,ltc2983";
> > +                reg = <0>;
> > +
> > +                #address-cells = <1>;
> > +                #size-cells = <0>;
> > +
> > +                adi,temperature-celcius;
> > +                interrupts = <20 IRQ_TYPE_EDGE_RISING>;
> > +                interrupt-parent = <&gpio>;
> > +
> > +                thermocouple@18 {
> > +                        reg = <18>;
> > +                        adi,sensor-type = <8>; //Type B
> > +                        adi,sensor-oc-current-microamp = <10>;
> > +                        adi,cold-junction-handle = <&diode5>;
> > +                };
> > +
> > +                diode5: diode@5 {
> > +                        reg = <5>;
> > +                        adi,sensor-type = <28>;
> > +                };
> > +
> > +                rsense2: rsense@2 {
> > +                        reg = <2>;
> > +                        adi,sensor-type = <29>;
> > +                        adi,rsense-val-micro-ohms = /bits/ 64
> > <1200000000>; //1.2Kohms
> > +                };
> > +
> > +                rtd@14 {
> > +                        reg = <14>;
> > +                        adi,sensor-type = <15>; //PT1000
> > +                        /*2-wire, internal gnd, no current
> > rotation*/
> > +                        adi,number-of-wires = <2>;
> > +                        adi,rsense-share;
> > +                        adi,excitation-current-microamp = <500>;
> > +                        adi,rsense-handle = <&rsense2>;
> > +                };
> > +
> > +                adc@10 {
> > +                        reg = <10>;
> > +                        adi,sensor-type = <30>;
> > +                        adi,single-ended;
> > +                };
> > +
> > +                thermistor@12 {
> > +                        reg = <12>;
> > +                        adi,sensor-type = <26>; //Steinhart
> > +                        adi,rsense-handle = <&rsense2>;
> > +                        adi,custom-sensor = /bits/ 64 <0x00F371EC
> > 0x12345678
> > +                                        0x2C0F8733 0x10018C66
> > 0xA0FEACCD
> > +                                        0x90021D99>; //6 entries
> > +                };
> > +
> > +                thermocouple@20 {
> > +                        reg = <20>;
> > +                        adi,sensor-type = <9>; //custom
> > thermocouple
> > +                        adi,single-ended;
> > +                        adi,custom-sensor = /bits/ 64
> > +                                 <(-50220000) 0
> > +                                  (-30200000) 99100000
> > +                                  (-5300000) 135400000
> > +                                  0 273150000
> > +                                  40200000 361200000
> > +                                  55300000 522100000
> > +                                  88300000 720300000
> > +                                  132200000 811200000
> > +                                  188700000 922500000
> > +                                  460400000 1000000000>; //10
> > pairs
> > +               };
> > +
> > +        };
> > +    };
> > +...
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 14a256e785ca..f747a9dc27f5 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -9497,6 +9497,7 @@ W:        
> > http://ez.analog.com/community/linux-device-drivers
> >  L:     linux-iio@vger.kernel.org
> >  S:     Supported
> >  F:     drivers/iio/temperature/ltc2983.c
> > +F:     Documentation/devicetree/bindings/iio/temperature/adi,ltc29
> > 83.yaml
> > 
> >  LTC4261 HARDWARE MONITOR DRIVER
> >  M:     Guenter Roeck <linux@roeck-us.net>
> > --
> > 2.23.0
> >
Rob Herring Oct. 7, 2019, 5:46 p.m. UTC | #4
On Mon, Oct 7, 2019 at 11:17 AM Sa, Nuno <Nuno.Sa@analog.com> wrote:
>
> On Mon, 2019-10-07 at 09:45 -0500, Rob Herring wrote:
> > On Fri, Oct 4, 2019 at 8:55 AM Nuno Sá <nuno.sa@analog.com> wrote:
> > > Document the LTC2983 temperature sensor devicetree bindings.
> > >
> > > Signed-off-by: Nuno Sá <nuno.sa@analog.com>
> > > ---
> > > Changes in v2:
> > >  * Drop maxItems in non-array elements;
> > >  * Set adi,mux-delay-config-us instead of adi,mux-delay-config;
> > >  * Wrapped lines at 80 char;
> > >  * Added comas to enum elements;
> > >  * Use real units in adi,excitation-current;
> > >  * Moved some enums to minimum and maximum;
> > >  * Grouped patternProperties and moved reg property as a generic
> > > property.
> > >
> > > Changes in v3:
> > >  * Add meaning to adi,sensor-type values which are not const;
> > >  * Add meaning to adi,filter-notch-freq values;
> > >  * Break up adi,sensor-config into human readable elements;
> > >  * Set maxItems/minItems at the same identation as allOf in
> > > adi,custom-sensor;
> > >  * Fixed the maximum value for adi,sensor-type for sensors with
> > > custom support;
> > >  * Changed license to GPL-2.0-only as it should be for new
> > > bindings;
> > >  * Changed spi0 to spi in the dts example;
> > >  * Updated the dts example to the new properties.
> > >
> > >  .../bindings/iio/temperature/adi,ltc2983.yaml | 479
> > > ++++++++++++++++++
> > >  MAINTAINERS                                   |   1 +
> > >  2 files changed, 480 insertions(+)
> > >  create mode 100644
> > > Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> > >
> > > diff --git
> > > a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > > l
> > > b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > > l
> > > new file mode 100644
> > > index 000000000000..b7101a0e84db
> > > --- /dev/null
> > > +++
> > > b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > > l
> > > @@ -0,0 +1,479 @@
> > > +# SPDX-License-Identifier: GPL-2.0-only
> >
> > (GPL-2.0-only OR BSD-2-Clause) for new bindings please.
>
> ack.
>
> > > +%YAML 1.2
> > > +---
> > > +$id:
> > > http://devicetree.org/schemas/iio/temperature/adi,ltc2983.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: Analog Devices LTC2983 Multi-sensor Temperature system
> > > +
> > > +maintainers:
> > > +  - Nuno Sá <nuno.sa@analog.com>
> > > +
> > > +description: |
> > > +  Analog Devices LTC2983 Multi-Sensor Digital Temperature
> > > Measurement System
> > > +
> > > https://www.analog.com/media/en/technical-documentation/data-sheets/2983fc.pdf
> > > +
> > > +properties:
> > > +  compatible:
> > > +    enum:
> > > +      - adi,ltc2983
> > > +
> > > +  reg:
> > > +    maxItems: 1
> > > +
> > > +  interrupts:
> > > +    maxItems: 1
> > > +
> > > +  adi,temperature-celcius:
> >
> > -celsius. However, that suffix is reserved for properties whose value
> > is in Celsius, so you'll have to come up with something else.
> >
> > How does one decide how to set this? Seems like the driver should
> > just
> > decide based on what it needs to present to the user.
>
> The device can report temperature in Celsius or Fahrenheit and that
> should be decided once. Hmm but now that I think about this, the iio
> standard attributes expect the value to be reported in milli degrees
> Celsius so I guess I should just drop this and don't report in
> Fahrenheit. Would this be ok Jonathan?
>
> > > +    description:
> > > +      If this property is present, the temperature is reported in
> > > Celsius.
> > > +    type: boolean
> > > +
> > > +  adi,mux-delay-config-us:
> > > +    description:
> > > +      The LTC2983 performs 2 or 3 internal conversion cycles per
> > > temperature
> > > +      result. Each conversion cycle is performed with different
> > > excitation and
> > > +      input multiplexer configurations. Prior to each conversion,
> > > these
> > > +      excitation circuits and input switch configurations are
> > > changed and an
> > > +      internal 1ms delay ensures settling prior to the conversion
> > > cycle in most
> > > +      cases. An extra delay can be configured using this property.
> > > The value is
> > > +      rounded to nearest 100us.
> > > +    allOf:
> > > +      - $ref: /schemas/types.yaml#/definitions/uint32
> > > +      - maximum: 255
> >
> > Standard unit suffixes already have a type, so just:
> >
> > maximum: 255
>
> got it.
>
> > > +
> > > +  adi,filter-notch-freq:
> > > +    description:
> > > +      Set's the default setting of the digital filter. The default
> > > is
> > > +      simultaneous 50/60Hz rejection.
> > > +      0 - 50/60Hz rejection
> > > +      1 - 60Hz rejection
> > > +      2 - 50Hz rejection
> > > +    allOf:
> > > +      - $ref: /schemas/types.yaml#/definitions/uint32
> > > +      - minimum: 0
> > > +      - maximum: 2
> >
> > Drop the '-' on the last entry (making the min/max a single schema).
>
> got it.
>
> > > +
> > > +  '#address-cells':
> > > +    const: 1
> > > +
> > > +  '#size-cells':
> > > +    const: 0
> > > +
> > > +patternProperties:
> > > +  ".*@([1-9]|1[0-9]|20)$":
> >
> > '.*' can be dropped.
> >
> > > +    type: object
> > > +
> > > +    properties:
> > > +      reg:
> > > +        description: |
> > > +          The channel number. It can be connected to one of the 20
> > > channels of
> > > +          the device.
> > > +        minimum: 1
> > > +        maximum: 20
> > > +
> > > +    required:
> > > +      - reg
> > > +
> > > +    patternProperties:
> > > +      "^thermocouple@.*":
> >
> > You've made this node a child of '.*@([1-9]|1[0-9]|20)$'. This needs
> > to be at the same level.
>
> You mean dropping "patternProperties" and having "^thermocouple@.*": on
> the same indent as ".*@([1-9]|1[0-9]|20)$":? It seems to be only one

Yes.

> working. I understood and tried something like:
>
> patternProperties:
>   "@([1-9]|1[0-9]|20)$":
>    (...)
>
>    patternProperties:

What you are saying here is you have a patternProperty called 'patternProperty'.

>      "^thermocouple@.*"

And then this is not a valid json-schema keyword for the property's schema.

>      description: "..."
>      type: object
>      properties:
>      (...)
>
> But this throws "'^thermocouple@' is not one of ['$ref',
> 'additionalItems', 'additionalProperties', 'allOf', 'anyOf', 'const',
> 'contains', 'default', 'dependencies', 'deprecated', 'description',
> 'else', 'enum', 'items', 'if', 'minItems', 'minimum', 'maxItems',
> 'maximum', 'not', 'oneOf', 'pattern', 'patternProperties',
> 'properties', 'required', 'then', 'type', 'typeSize']"
>
> Also, should I also drop the ".*" in "^thermocouple@.*"?

Yes.

> > > +        type: object
> > > +        description: |
> >
> > You can drop the '|' where you don't need any formatting.
>
> got it.
>
> > > +          Represents a thermocouple sensor which is connected to
> > > one of the device
> > > +          channels.
> > > +
> > > +        properties:
> > > +          adi,sensor-type:
> > > +            description: |
> > > +              Identifies the type of thermocouple connected to the
> > > device.
> > > +              1 - Type J Thermocouple
> > > +              2 - Type K Thermocouple
> > > +              3 - Type E Thermocouple
> > > +              4 - Type N Thermocouple
> > > +              5 - Type R Thermocouple
> > > +              6 - Type S Thermocouple
> > > +              7 - Type T Thermocouple
> > > +              8 - Type B Thermocouple
> > > +              9 - Custom Thermocouple
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> >
> > You can move the type definition under ".*@([1-9]|1[0-9]|20)$" and
> > then just have the min/max here.
>
> And how could I add meaning to the values. Could I add all in the
> "parent" node?

No, they have to be at the correct level. You can keep the
descriptions here. Just do:

adi,sensor-type:
 description: ...
 $ref: /schemas/types.yaml#/definitions/uint32

under ".*@([1-9]|1[0-9]|20)$" and drop the 'allOf: [ $ref: ...]' part.

>
> > > +              - minimum: 1
> > > +              - maximum: 9
> > > +
> > > +          adi,single-ended:
> > > +            description: |
> > > +              Boolean property which set's the thermocouple as
> > > single-ended.
> > > +            type: boolean
> > > +
> > > +          adi,sensor-oc-current-microamp:
> > > +            description: |
> > > +              This property set's the pulsed current value applied
> > > during
> > > +              open-circuit detect.
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > +              - enum: [10, 100, 500, 1000]
> > > +
> > > +          adi,cold-junction-handle:
> > > +            description: |
> > > +              Phandle which points to a sensor object responsible
> > > for measuring
> > > +              the thermocouple cold junction temperature.
> > > +            $ref: "/schemas/types.yaml#/definitions/phandle"
> > > +
> > > +          adi,custom-sensor:
> > > +            description: |
> > > +              This is a table, where each entry should be a pair
> > > of
> > > +              voltage(mv)-temperature(K). The entries must be
> > > given in nv and uK
> > > +              so that, the original values must be multiplied by
> > > 1000000. For
> >
> > We normally do things in microVolts. It seems strange to need 64-bits
> > of range for voltage and temperature.
>
> This device support very high resolutions (so we have fractional
> values). That is why I'm multiplying by 1000000 and using nV. And even
> so, I already loose some bits. The 64bits are needed mainly because of
> the Temperature and again the resolution I want to maximize. Doing
> int(max(temp)) * 1000000, we need 64bits.
>
> >
> > > +              more details look at table 69 and 70.
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/int64-array
> >
> > Fails on 'make dt_binding_check':
> >
> > Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml:
> > Unresolvable JSON pointer: 'definitions/int64-array'
>
> I was aware of this but I do not know how to proceed so I was waiting
> for your comment. I do have negative values, so uint does not apply.
> What can I use here?
>
> > If this is pairs of values, it should really be defined as a matrix:
> >
> > minItems: 3
> > maxItems: 64
> > items:
> >   minItems: 2
> >   maxItems: 2
> >
> > Though I'll need to add uint64-matrix as a type (assuming this really
> > needs to be 64-bit).
>
> I reinforce that I do need signed values here.

I can add those as well. At least for now, they are going to end up
being the exact same definition because IIRC while dtc takes signed
input, that's lost by the time we emit the output.

>
> >
> > > +            minItems: 6
> > > +            maxItems: 128
> > > +
> > > +        required:
> > > +          - adi,sensor-type
> > > +
> > > +      "^diode@.*":
> > > +        type: object
> > > +        description: |
> > > +          Represents a diode sensor which is connected to one of
> > > the device
> > > +          channels.
> > > +
> > > +        properties:
> > > +          adi,sensor-type:
> > > +            description: Identifies the sensor as a diode.
> > > +            const: 28
> > > +
> > > +          adi,single-ended:
> > > +            description: Boolean property which set's the diode as
> > > single-ended.
> > > +            type: boolean
> > > +
> > > +          adi,three-conversion-cycles:
> > > +            description: |
> > > +              Boolean property which set's three conversion cycles
> > > removing
> > > +              parasitic resistance effects between the LTC2983 and
> > > the diode.
> > > +            type: boolean
> > > +
> > > +          adi,average-on:
> > > +            description: |
> > > +              Boolean property which enables a running average of
> > > the diode
> > > +              temperature reading. This reduces the noise when the
> > > diode is used
> > > +              as a cold junction temperature element on an
> > > isothermal block
> > > +              where temperatures change slowly.
> > > +            type: boolean
> > > +
> > > +          adi,excitation-current-microamp:
> > > +            description: |
> > > +              This property controls the magnitude of the
> > > excitation current
> > > +              applied to the diode. Depending on the number of
> > > conversions
> > > +              cycles, this property will assume different
> > > predefined values on
> > > +              each cycle. Just set the value of the first cycle
> > > (1l).
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > +              - enum: [10, 20, 40, 80]
> > > +
> > > +          adi,ideal-factor-value:
> > > +            description: |
> > > +              This property sets the diode ideality factor. The
> > > real value must
> > > +              be multiplied by 1000000 to remove the fractional
> > > part. For more
> > > +              information look at table 20 of the datasheet.
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > +
> > > +        required:
> > > +          - adi,sensor-type
> > > +
> > > +      "^rtd@.*":
> > > +        type: object
> > > +        description: |
> > > +          Represents a rtd sensor which is connected to one of the
> > > device channels.
> > > +
> > > +        properties:
> > > +          reg:
> > > +            minimum: 2
> > > +
> > > +          adi,sensor-type:
> > > +            description: |
> > > +              Identifies the type of RTD connected to the device.
> > > +              10 - RTD PT-10
> > > +              11 - RTD PT-50
> > > +              12 - RTD PT-100
> > > +              13 - RTD PT-200
> > > +              14 - RTD PT-500
> > > +              15 - RTD PT-1000
> > > +              16 - RTD PT-1000 (0.00375)
> > > +              17 - RTD NI-120
> > > +              18 - RTD Custom
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > +              - minimum: 10
> > > +              - maximum: 18
> > > +
> > > +          adi,rsense-handle:
> > > +            description: |
> > > +              Phandle pointing to a rsense object associated with
> > > this RTD.
> > > +            $ref: "/schemas/types.yaml#/definitions/phandle"
> > > +
> > > +          adi,number-of-wires:
> > > +            description: |
> > > +              Identifies the number of wires used by the RTD.
> > > Setting this
> > > +              property to 5 means 4 wires with Kelvin Rsense.
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > +              - enum: [2, 3, 4, 5]
> > > +
> > > +          adi,rsense-share:
> > > +            description: |
> > > +              Boolean property which enables Rsense sharing, where
> > > one sense
> > > +              resistor is used for multiple 2-, 3-, and/or 4-wire
> > > RTDs.
> > > +            type: boolean
> > > +
> > > +          adi,current-rotate:
> > > +            description: |
> > > +              Boolean property which enables excitation current
> > > rotation to
> > > +              automatically remove parasitic thermocouple effects.
> > > Note that
> > > +              this property is not allowed for 2- and 3-wire RTDs.
> > > +            type: boolean
> > > +
> > > +          adi,excitation-current-microamp:
> > > +            description: |
> > > +              This property controls the magnitude of the
> > > excitation current
> > > +              applied to the RTD.
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> >
> > You can drop the type here too.
>
> got it.
>
> > > +              - enum: [5, 10, 25, 50, 100, 250, 500, 1000]
> > > +
> > > +          adi,rtd-curve:
> > > +            description: |
> > > +              This property set the RTD curve used and the
> > > corresponding
> > > +              Callendar-VanDusen constants. Look at table 30 of
> > > the datasheet.
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > +              - minimum: 0
> > > +              - maximum: 3
> > > +
> > > +          adi,custom-sensor:
> > > +            description: |
> > > +              This is a table, where each entry should be a pair
> > > of
> > > +              resistance(ohm)-temperature(K). The entries added
> > > here are in uohm
> > > +              and uK. For more details values look at table 74 and
> > > 75.
> >
> > It's not great to make one property name have different meanings.
>
> Would you prefer to have something like "custom-rtd", "custom-
> thermoucouple" and so on? I would have to adapt the code but I don't
> think it would need to much of a change.

I don't really know enough about this device to say... What does
'custom' mean here?

>
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint64-
> > > array
> > > +            minItems: 6
> > > +            maxItems: 128
> > > +
> > > +        required:
> > > +          - adi,sensor-type
> > > +          - adi,rsense-handle
> > > +
> > > +        dependencies:
> > > +          adi,current-rotate: [ adi,rsense-share ]
> > > +
> > > +      "^thermistor@.*":
> > > +        type: object
> > > +        description: |
> > > +          Represents a thermistor sensor which is connected to one
> > > of the device
> > > +          channels.
> > > +
> > > +        properties:
> > > +          adi,sensor-type:
> > > +            description: |
> > > +              Identifies the type of thermistor connected to the
> > > +              device.
> > > +              19 - Thermistor 44004/44033 2.252kohm at 25°C
> > > +              20 - Thermistor 44005/44030 3kohm at 25°C
> > > +              21 - Thermistor 44007/44034 5kohm at 25°C
> > > +              22 - Thermistor 44006/44031 10kohm at 25°C
> > > +              23 - Thermistor 44008/44032 30kohm at 25°C
> > > +              24 - Thermistor YSI 400 2.252kohm at 25°C
> > > +              25 - Thermistor Spectrum 1003k 1kohm
> > > +              26 - Thermistor Custom Steinhart-Hart
> > > +              27 - Custom Thermistor
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > +              - minimum: 19
> > > +              - maximum: 27
> > > +
> > > +          adi,rsense-handle:
> > > +            description: |
> > > +              Phandle pointing to a rsense object associated with
> > > this
> > > +              thermistor.
> > > +            $ref: "/schemas/types.yaml#/definitions/phandle"
> > > +
> > > +          adi,single-ended:
> > > +            description: |
> > > +              Boolean property which set's the thermistor as
> > > single-ended.
> > > +            type: boolean
> > > +
> > > +          adi,rsense-share:
> > > +            description: |
> > > +              Boolean property which enables Rsense sharing, where
> > > one sense
> > > +              resistor is used for multiple thermistors. Note that
> > > this property
> > > +              is ignored if adi,single-ended is set.
> > > +            type: boolean
> > > +
> > > +          adi,current-rotate:
> > > +            description: |
> > > +              Boolean property which enables excitation current
> > > rotation to
> > > +              automatically remove parasitic thermocouple effects.
> > > +            type: boolean
> > > +
> > > +          adi,excitation-current-nanoamp:
> > > +            description: |
> > > +              This property controls the magnitude of the
> > > excitation current
> > > +              applied to the thermistor. Value 0 set's the sensor
> > > in auto-range
> > > +              mode.
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > +              - enum: [0, 250, 500, 1000, 5000, 10000, 25000,
> > > 50000, 100000,
> > > +                       250000, 500000, 1000000]
> > > +
> > > +          adi,custom-sensor:
> > > +            description: |
> > > +              This is a table, where each entry should be a pair
> > > of
> > > +              resistance(ohm)-temperature(K). The entries added
> > > here are in uohm
> > > +              and uK only for custom thermistors. For more details
> > > look at table
> > > +              78 and 79. Steinhart-Hart coefficients are also
> > > supported and can
> > > +              be programmed into the device memory using this
> > > property. For
> > > +              Steinhart sensors, this table has a constant size of
> > > 6 entries
> > > +              (defining the coefficients) and the values are given
> > > in the raw
> > > +              format. Look at table 82 for more information.
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint64-
> > > array
> > > +            minItems: 6
> > > +            maxItems: 128
> > > +
>
> If I'm to replace this property as proposed before, would it make sense
> also to split this in custom-thermistor and custom-steinhart or just
> steinhart?

Seems like it as the data is completely different.

>
> > > +        required:
> > > +          - adi,sensor-type
> > > +          - adi,rsense-handle
> > > +
> > > +        dependencies:
> > > +          adi,current-rotate: [ adi,rsense-share ]
> > > +
> > > +      "^adc@.*":
> > > +        type: object
> > > +        description: Represents a channel which is being used as a
> > > direct adc.
> > > +
> > > +        properties:
> > > +          adi,sensor-type:
> > > +            description: Identifies the sensor as a direct adc.
> > > +            const: 30
> > > +
> > > +          adi,single-ended:
> > > +            description: Boolean property which set's the adc as
> > > single-ended.
> > > +            type: boolean
> > > +
> > > +        required:
> > > +          - adi,sensor-type
> > > +
> > > +      "^rsense@.*":
> > > +        type: object
> > > +        description: |
> > > +          Represents a rsense which is connected to one of the
> > > device channels.
> > > +          Rsense are used by thermistors and RTD's.
> > > +
> > > +        properties:
> > > +          reg:
> > > +            minimum: 2
> > > +
> > > +          adi,sensor-type:
> > > +            description: Identifies the sensor as a rsense.
> > > +            const: 29
> > > +
> > > +          adi,rsense-val-micro-ohms:
> > > +            description: |
> > > +              Sets the value of the sense resistor. Look at table
> > > 20 of the
> > > +              datasheet for information.
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint64
> >
> > -micro-ohms is already defined to be 32-bit.
>
> I do need a 64-bit variable here. Should I still remove the $ref or how
> can I proceed?

We could add -milli-ohms. According to the datasheet, it's 0-131kohms
in 1/1024ohm steps.

Rob
Nuno Sa Oct. 8, 2019, 7:45 a.m. UTC | #5
On Mon, 2019-10-07 at 12:46 -0500, Rob Herring wrote:
> 
> On Mon, Oct 7, 2019 at 11:17 AM Sa, Nuno <Nuno.Sa@analog.com> wrote:
> > On Mon, 2019-10-07 at 09:45 -0500, Rob Herring wrote:
> > > On Fri, Oct 4, 2019 at 8:55 AM Nuno Sá <nuno.sa@analog.com>
> > > wrote:
> > > > Document the LTC2983 temperature sensor devicetree bindings.
> > > > 
> > > > Signed-off-by: Nuno Sá <nuno.sa@analog.com>
> > > > ---
> > > > Changes in v2:
> > > >  * Drop maxItems in non-array elements;
> > > >  * Set adi,mux-delay-config-us instead of adi,mux-delay-config;
> > > >  * Wrapped lines at 80 char;
> > > >  * Added comas to enum elements;
> > > >  * Use real units in adi,excitation-current;
> > > >  * Moved some enums to minimum and maximum;
> > > >  * Grouped patternProperties and moved reg property as a
> > > > generic
> > > > property.
> > > > 
> > > > Changes in v3:
> > > >  * Add meaning to adi,sensor-type values which are not const;
> > > >  * Add meaning to adi,filter-notch-freq values;
> > > >  * Break up adi,sensor-config into human readable elements;
> > > >  * Set maxItems/minItems at the same identation as allOf in
> > > > adi,custom-sensor;
> > > >  * Fixed the maximum value for adi,sensor-type for sensors with
> > > > custom support;
> > > >  * Changed license to GPL-2.0-only as it should be for new
> > > > bindings;
> > > >  * Changed spi0 to spi in the dts example;
> > > >  * Updated the dts example to the new properties.
> > > > 
> > > >  .../bindings/iio/temperature/adi,ltc2983.yaml | 479
> > > > ++++++++++++++++++
> > > >  MAINTAINERS                                   |   1 +
> > > >  2 files changed, 480 insertions(+)
> > > >  create mode 100644
> > > > Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.y
> > > > aml
> > > > 
> > > > diff --git
> > > > a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983
> > > > .yam
> > > > l
> > > > b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983
> > > > .yam
> > > > l
> > > > new file mode 100644
> > > > index 000000000000..b7101a0e84db
> > > > --- /dev/null
> > > > +++
> > > > b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983
> > > > .yam
> > > > l
> > > > @@ -0,0 +1,479 @@
> > > > +# SPDX-License-Identifier: GPL-2.0-only
> > > 
> > > (GPL-2.0-only OR BSD-2-Clause) for new bindings please.
> > 
> > ack.
> > 
> > > > +%YAML 1.2
> > > > +---
> > > > +$id:
> > > > http://devicetree.org/schemas/iio/temperature/adi,ltc2983.yaml#
> > > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > > +
> > > > +title: Analog Devices LTC2983 Multi-sensor Temperature system
> > > > +
> > > > +maintainers:
> > > > +  - Nuno Sá <nuno.sa@analog.com>
> > > > +
> > > > +description: |
> > > > +  Analog Devices LTC2983 Multi-Sensor Digital Temperature
> > > > Measurement System
> > > > +
> > > > https://www.analog.com/media/en/technical-documentation/data-sheets/2983fc.pdf
> > > > +
> > > > +properties:
> > > > +  compatible:
> > > > +    enum:
> > > > +      - adi,ltc2983
> > > > +
> > > > +  reg:
> > > > +    maxItems: 1
> > > > +
> > > > +  interrupts:
> > > > +    maxItems: 1
> > > > +
> > > > +  adi,temperature-celcius:
> > > 
> > > -celsius. However, that suffix is reserved for properties whose
> > > value
> > > is in Celsius, so you'll have to come up with something else.
> > > 
> > > How does one decide how to set this? Seems like the driver should
> > > just
> > > decide based on what it needs to present to the user.
> > 
> > The device can report temperature in Celsius or Fahrenheit and that
> > should be decided once. Hmm but now that I think about this, the
> > iio
> > standard attributes expect the value to be reported in milli
> > degrees
> > Celsius so I guess I should just drop this and don't report in
> > Fahrenheit. Would this be ok Jonathan?
> > 
> > > > +    description:
> > > > +      If this property is present, the temperature is reported
> > > > in
> > > > Celsius.
> > > > +    type: boolean
> > > > +
> > > > +  adi,mux-delay-config-us:
> > > > +    description:
> > > > +      The LTC2983 performs 2 or 3 internal conversion cycles
> > > > per
> > > > temperature
> > > > +      result. Each conversion cycle is performed with
> > > > different
> > > > excitation and
> > > > +      input multiplexer configurations. Prior to each
> > > > conversion,
> > > > these
> > > > +      excitation circuits and input switch configurations are
> > > > changed and an
> > > > +      internal 1ms delay ensures settling prior to the
> > > > conversion
> > > > cycle in most
> > > > +      cases. An extra delay can be configured using this
> > > > property.
> > > > The value is
> > > > +      rounded to nearest 100us.
> > > > +    allOf:
> > > > +      - $ref: /schemas/types.yaml#/definitions/uint32
> > > > +      - maximum: 255
> > > 
> > > Standard unit suffixes already have a type, so just:
> > > 
> > > maximum: 255
> > 
> > got it.
> > 
> > > > +
> > > > +  adi,filter-notch-freq:
> > > > +    description:
> > > > +      Set's the default setting of the digital filter. The
> > > > default
> > > > is
> > > > +      simultaneous 50/60Hz rejection.
> > > > +      0 - 50/60Hz rejection
> > > > +      1 - 60Hz rejection
> > > > +      2 - 50Hz rejection
> > > > +    allOf:
> > > > +      - $ref: /schemas/types.yaml#/definitions/uint32
> > > > +      - minimum: 0
> > > > +      - maximum: 2
> > > 
> > > Drop the '-' on the last entry (making the min/max a single
> > > schema).
> > 
> > got it.
> > 
> > > > +
> > > > +  '#address-cells':
> > > > +    const: 1
> > > > +
> > > > +  '#size-cells':
> > > > +    const: 0
> > > > +
> > > > +patternProperties:
> > > > +  ".*@([1-9]|1[0-9]|20)$":
> > > 
> > > '.*' can be dropped.
> > > 
> > > > +    type: object
> > > > +
> > > > +    properties:
> > > > +      reg:
> > > > +        description: |
> > > > +          The channel number. It can be connected to one of
> > > > the 20
> > > > channels of
> > > > +          the device.
> > > > +        minimum: 1
> > > > +        maximum: 20
> > > > +
> > > > +    required:
> > > > +      - reg
> > > > +
> > > > +    patternProperties:
> > > > +      "^thermocouple@.*":
> > > 
> > > You've made this node a child of '.*@([1-9]|1[0-9]|20)$'. This
> > > needs
> > > to be at the same level.
> > 
> > You mean dropping "patternProperties" and having
> > "^thermocouple@.*": on
> > the same indent as ".*@([1-9]|1[0-9]|20)$":? It seems to be only
> > one
> 
> Yes.
> 
> > working. I understood and tried something like:
> > 
> > patternProperties:
> >   "@([1-9]|1[0-9]|20)$":
> >    (...)
> > 
> >    patternProperties:
> 
> What you are saying here is you have a patternProperty called
> 'patternProperty'.
> 
> >      "^thermocouple@.*"
> 
> And then this is not a valid json-schema keyword for the property's
> schema.
> 
> >      description: "..."
> >      type: object
> >      properties:
> >      (...)
> > 
> > But this throws "'^thermocouple@' is not one of ['$ref',
> > 'additionalItems', 'additionalProperties', 'allOf', 'anyOf',
> > 'const',
> > 'contains', 'default', 'dependencies', 'deprecated', 'description',
> > 'else', 'enum', 'items', 'if', 'minItems', 'minimum', 'maxItems',
> > 'maximum', 'not', 'oneOf', 'pattern', 'patternProperties',
> > 'properties', 'required', 'then', 'type', 'typeSize']"
> > 
> > Also, should I also drop the ".*" in "^thermocouple@.*"?
> 
> Yes.
> 
> > > > +        type: object
> > > > +        description: |
> > > 
> > > You can drop the '|' where you don't need any formatting.
> > 
> > got it.
> > 
> > > > +          Represents a thermocouple sensor which is connected
> > > > to
> > > > one of the device
> > > > +          channels.
> > > > +
> > > > +        properties:
> > > > +          adi,sensor-type:
> > > > +            description: |
> > > > +              Identifies the type of thermocouple connected to
> > > > the
> > > > device.
> > > > +              1 - Type J Thermocouple
> > > > +              2 - Type K Thermocouple
> > > > +              3 - Type E Thermocouple
> > > > +              4 - Type N Thermocouple
> > > > +              5 - Type R Thermocouple
> > > > +              6 - Type S Thermocouple
> > > > +              7 - Type T Thermocouple
> > > > +              8 - Type B Thermocouple
> > > > +              9 - Custom Thermocouple
> > > > +            allOf:
> > > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > 
> > > You can move the type definition under ".*@([1-9]|1[0-9]|20)$"
> > > and
> > > then just have the min/max here.
> > 
> > And how could I add meaning to the values. Could I add all in the
> > "parent" node?
> 
> No, they have to be at the correct level. You can keep the
> descriptions here. Just do:
> 
> adi,sensor-type:
>  description: ...
>  $ref: /schemas/types.yaml#/definitions/uint32
> 
> under ".*@([1-9]|1[0-9]|20)$" and drop the 'allOf: [ $ref: ...]'
> part.
> 
> > > > +              - minimum: 1
> > > > +              - maximum: 9
> > > > +
> > > > +          adi,single-ended:
> > > > +            description: |
> > > > +              Boolean property which set's the thermocouple as
> > > > single-ended.
> > > > +            type: boolean
> > > > +
> > > > +          adi,sensor-oc-current-microamp:
> > > > +            description: |
> > > > +              This property set's the pulsed current value
> > > > applied
> > > > during
> > > > +              open-circuit detect.
> > > > +            allOf:
> > > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > > +              - enum: [10, 100, 500, 1000]
> > > > +
> > > > +          adi,cold-junction-handle:
> > > > +            description: |
> > > > +              Phandle which points to a sensor object
> > > > responsible
> > > > for measuring
> > > > +              the thermocouple cold junction temperature.
> > > > +            $ref: "/schemas/types.yaml#/definitions/phandle"
> > > > +
> > > > +          adi,custom-sensor:
> > > > +            description: |
> > > > +              This is a table, where each entry should be a
> > > > pair
> > > > of
> > > > +              voltage(mv)-temperature(K). The entries must be
> > > > given in nv and uK
> > > > +              so that, the original values must be multiplied
> > > > by
> > > > 1000000. For
> > > 
> > > We normally do things in microVolts. It seems strange to need 64-
> > > bits
> > > of range for voltage and temperature.
> > 
> > This device support very high resolutions (so we have fractional
> > values). That is why I'm multiplying by 1000000 and using nV. And
> > even
> > so, I already loose some bits. The 64bits are needed mainly because
> > of
> > the Temperature and again the resolution I want to maximize. Doing
> > int(max(temp)) * 1000000, we need 64bits.
> > 
> > > > +              more details look at table 69 and 70.
> > > > +            allOf:
> > > > +              - $ref: /schemas/types.yaml#/definitions/int64-
> > > > array
> > > 
> > > Fails on 'make dt_binding_check':
> > > 
> > > Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > > l:
> > > Unresolvable JSON pointer: 'definitions/int64-array'
> > 
> > I was aware of this but I do not know how to proceed so I was
> > waiting
> > for your comment. I do have negative values, so uint does not
> > apply.
> > What can I use here?
> > 
> > > If this is pairs of values, it should really be defined as a
> > > matrix:
> > > 
> > > minItems: 3
> > > maxItems: 64
> > > items:
> > >   minItems: 2
> > >   maxItems: 2
> > > 
> > > Though I'll need to add uint64-matrix as a type (assuming this
> > > really
> > > needs to be 64-bit).
> > 
> > I reinforce that I do need signed values here.
> 
> I can add those as well. At least for now, they are going to end up
> being the exact same definition because IIRC while dtc takes signed
> input, that's lost by the time we emit the output.

So, can I just add something like int64-matrix?

> > > > +            minItems: 6
> > > > +            maxItems: 128
> > > > +
> > > > +        required:
> > > > +          - adi,sensor-type
> > > > +
> > > > +      "^diode@.*":
> > > > +        type: object
> > > > +        description: |
> > > > +          Represents a diode sensor which is connected to one
> > > > of
> > > > the device
> > > > +          channels.
> > > > +
> > > > +        properties:
> > > > +          adi,sensor-type:
> > > > +            description: Identifies the sensor as a diode.
> > > > +            const: 28
> > > > +
> > > > +          adi,single-ended:
> > > > +            description: Boolean property which set's the
> > > > diode as
> > > > single-ended.
> > > > +            type: boolean
> > > > +
> > > > +          adi,three-conversion-cycles:
> > > > +            description: |
> > > > +              Boolean property which set's three conversion
> > > > cycles
> > > > removing
> > > > +              parasitic resistance effects between the LTC2983
> > > > and
> > > > the diode.
> > > > +            type: boolean
> > > > +
> > > > +          adi,average-on:
> > > > +            description: |
> > > > +              Boolean property which enables a running average
> > > > of
> > > > the diode
> > > > +              temperature reading. This reduces the noise when
> > > > the
> > > > diode is used
> > > > +              as a cold junction temperature element on an
> > > > isothermal block
> > > > +              where temperatures change slowly.
> > > > +            type: boolean
> > > > +
> > > > +          adi,excitation-current-microamp:
> > > > +            description: |
> > > > +              This property controls the magnitude of the
> > > > excitation current
> > > > +              applied to the diode. Depending on the number of
> > > > conversions
> > > > +              cycles, this property will assume different
> > > > predefined values on
> > > > +              each cycle. Just set the value of the first
> > > > cycle
> > > > (1l).
> > > > +            allOf:
> > > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > > +              - enum: [10, 20, 40, 80]
> > > > +
> > > > +          adi,ideal-factor-value:
> > > > +            description: |
> > > > +              This property sets the diode ideality factor.
> > > > The
> > > > real value must
> > > > +              be multiplied by 1000000 to remove the
> > > > fractional
> > > > part. For more
> > > > +              information look at table 20 of the datasheet.
> > > > +            allOf:
> > > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > > +
> > > > +        required:
> > > > +          - adi,sensor-type
> > > > +
> > > > +      "^rtd@.*":
> > > > +        type: object
> > > > +        description: |
> > > > +          Represents a rtd sensor which is connected to one of
> > > > the
> > > > device channels.
> > > > +
> > > > +        properties:
> > > > +          reg:
> > > > +            minimum: 2
> > > > +
> > > > +          adi,sensor-type:
> > > > +            description: |
> > > > +              Identifies the type of RTD connected to the
> > > > device.
> > > > +              10 - RTD PT-10
> > > > +              11 - RTD PT-50
> > > > +              12 - RTD PT-100
> > > > +              13 - RTD PT-200
> > > > +              14 - RTD PT-500
> > > > +              15 - RTD PT-1000
> > > > +              16 - RTD PT-1000 (0.00375)
> > > > +              17 - RTD NI-120
> > > > +              18 - RTD Custom
> > > > +            allOf:
> > > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > > +              - minimum: 10
> > > > +              - maximum: 18
> > > > +
> > > > +          adi,rsense-handle:
> > > > +            description: |
> > > > +              Phandle pointing to a rsense object associated
> > > > with
> > > > this RTD.
> > > > +            $ref: "/schemas/types.yaml#/definitions/phandle"
> > > > +
> > > > +          adi,number-of-wires:
> > > > +            description: |
> > > > +              Identifies the number of wires used by the RTD.
> > > > Setting this
> > > > +              property to 5 means 4 wires with Kelvin Rsense.
> > > > +            allOf:
> > > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > > +              - enum: [2, 3, 4, 5]
> > > > +
> > > > +          adi,rsense-share:
> > > > +            description: |
> > > > +              Boolean property which enables Rsense sharing,
> > > > where
> > > > one sense
> > > > +              resistor is used for multiple 2-, 3-, and/or 4-
> > > > wire
> > > > RTDs.
> > > > +            type: boolean
> > > > +
> > > > +          adi,current-rotate:
> > > > +            description: |
> > > > +              Boolean property which enables excitation
> > > > current
> > > > rotation to
> > > > +              automatically remove parasitic thermocouple
> > > > effects.
> > > > Note that
> > > > +              this property is not allowed for 2- and 3-wire
> > > > RTDs.
> > > > +            type: boolean
> > > > +
> > > > +          adi,excitation-current-microamp:
> > > > +            description: |
> > > > +              This property controls the magnitude of the
> > > > excitation current
> > > > +              applied to the RTD.
> > > > +            allOf:
> > > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > 
> > > You can drop the type here too.
> > 
> > got it.
> > 
> > > > +              - enum: [5, 10, 25, 50, 100, 250, 500, 1000]
> > > > +
> > > > +          adi,rtd-curve:
> > > > +            description: |
> > > > +              This property set the RTD curve used and the
> > > > corresponding
> > > > +              Callendar-VanDusen constants. Look at table 30
> > > > of
> > > > the datasheet.
> > > > +            allOf:
> > > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > > +              - minimum: 0
> > > > +              - maximum: 3
> > > > +
> > > > +          adi,custom-sensor:
> > > > +            description: |
> > > > +              This is a table, where each entry should be a
> > > > pair
> > > > of
> > > > +              resistance(ohm)-temperature(K). The entries
> > > > added
> > > > here are in uohm
> > > > +              and uK. For more details values look at table 74
> > > > and
> > > > 75.
> > > 
> > > It's not great to make one property name have different meanings.
> > 
> > Would you prefer to have something like "custom-rtd", "custom-
> > thermoucouple" and so on? I would have to adapt the code but I
> > don't
> > think it would need to much of a change.
> 
> I don't really know enough about this device to say... What does
> 'custom' mean here?

Custom, is really if a user wants to provide a custom sensor, which is
only supported for thermocouples, thermistors and RTDs. In those cases,
the user provides a table of points describing the sensor response,
which for example, on a thermocouple is voltage-temperature.

> > > > +            allOf:
> > > > +              - $ref: /schemas/types.yaml#/definitions/uint64-
> > > > array
> > > > +            minItems: 6
> > > > +            maxItems: 128
> > > > +
> > > > +        required:
> > > > +          - adi,sensor-type
> > > > +          - adi,rsense-handle
> > > > +
> > > > +        dependencies:
> > > > +          adi,current-rotate: [ adi,rsense-share ]
> > > > +
> > > > +      "^thermistor@.*":
> > > > +        type: object
> > > > +        description: |
> > > > +          Represents a thermistor sensor which is connected to
> > > > one
> > > > of the device
> > > > +          channels.
> > > > +
> > > > +        properties:
> > > > +          adi,sensor-type:
> > > > +            description: |
> > > > +              Identifies the type of thermistor connected to
> > > > the
> > > > +              device.
> > > > +              19 - Thermistor 44004/44033 2.252kohm at 25°C
> > > > +              20 - Thermistor 44005/44030 3kohm at 25°C
> > > > +              21 - Thermistor 44007/44034 5kohm at 25°C
> > > > +              22 - Thermistor 44006/44031 10kohm at 25°C
> > > > +              23 - Thermistor 44008/44032 30kohm at 25°C
> > > > +              24 - Thermistor YSI 400 2.252kohm at 25°C
> > > > +              25 - Thermistor Spectrum 1003k 1kohm
> > > > +              26 - Thermistor Custom Steinhart-Hart
> > > > +              27 - Custom Thermistor
> > > > +            allOf:
> > > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > > +              - minimum: 19
> > > > +              - maximum: 27
> > > > +
> > > > +          adi,rsense-handle:
> > > > +            description: |
> > > > +              Phandle pointing to a rsense object associated
> > > > with
> > > > this
> > > > +              thermistor.
> > > > +            $ref: "/schemas/types.yaml#/definitions/phandle"
> > > > +
> > > > +          adi,single-ended:
> > > > +            description: |
> > > > +              Boolean property which set's the thermistor as
> > > > single-ended.
> > > > +            type: boolean
> > > > +
> > > > +          adi,rsense-share:
> > > > +            description: |
> > > > +              Boolean property which enables Rsense sharing,
> > > > where
> > > > one sense
> > > > +              resistor is used for multiple thermistors. Note
> > > > that
> > > > this property
> > > > +              is ignored if adi,single-ended is set.
> > > > +            type: boolean
> > > > +
> > > > +          adi,current-rotate:
> > > > +            description: |
> > > > +              Boolean property which enables excitation
> > > > current
> > > > rotation to
> > > > +              automatically remove parasitic thermocouple
> > > > effects.
> > > > +            type: boolean
> > > > +
> > > > +          adi,excitation-current-nanoamp:
> > > > +            description: |
> > > > +              This property controls the magnitude of the
> > > > excitation current
> > > > +              applied to the thermistor. Value 0 set's the
> > > > sensor
> > > > in auto-range
> > > > +              mode.
> > > > +            allOf:
> > > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > > +              - enum: [0, 250, 500, 1000, 5000, 10000, 25000,
> > > > 50000, 100000,
> > > > +                       250000, 500000, 1000000]
> > > > +
> > > > +          adi,custom-sensor:
> > > > +            description: |
> > > > +              This is a table, where each entry should be a
> > > > pair
> > > > of
> > > > +              resistance(ohm)-temperature(K). The entries
> > > > added
> > > > here are in uohm
> > > > +              and uK only for custom thermistors. For more
> > > > details
> > > > look at table
> > > > +              78 and 79. Steinhart-Hart coefficients are also
> > > > supported and can
> > > > +              be programmed into the device memory using this
> > > > property. For
> > > > +              Steinhart sensors, this table has a constant
> > > > size of
> > > > 6 entries
> > > > +              (defining the coefficients) and the values are
> > > > given
> > > > in the raw
> > > > +              format. Look at table 82 for more information.
> > > > +            allOf:
> > > > +              - $ref: /schemas/types.yaml#/definitions/uint64-
> > > > array
> > > > +            minItems: 6
> > > > +            maxItems: 128
> > > > +
> > 
> > If I'm to replace this property as proposed before, would it make
> > sense
> > also to split this in custom-thermistor and custom-steinhart or
> > just
> > steinhart?
> 
> Seems like it as the data is completely different.

I'm also feeling like I should have this property split in 2.

> > > > +        required:
> > > > +          - adi,sensor-type
> > > > +          - adi,rsense-handle
> > > > +
> > > > +        dependencies:
> > > > +          adi,current-rotate: [ adi,rsense-share ]
> > > > +
> > > > +      "^adc@.*":
> > > > +        type: object
> > > > +        description: Represents a channel which is being used
> > > > as a
> > > > direct adc.
> > > > +
> > > > +        properties:
> > > > +          adi,sensor-type:
> > > > +            description: Identifies the sensor as a direct
> > > > adc.
> > > > +            const: 30
> > > > +
> > > > +          adi,single-ended:
> > > > +            description: Boolean property which set's the adc
> > > > as
> > > > single-ended.
> > > > +            type: boolean
> > > > +
> > > > +        required:
> > > > +          - adi,sensor-type
> > > > +
> > > > +      "^rsense@.*":
> > > > +        type: object
> > > > +        description: |
> > > > +          Represents a rsense which is connected to one of the
> > > > device channels.
> > > > +          Rsense are used by thermistors and RTD's.
> > > > +
> > > > +        properties:
> > > > +          reg:
> > > > +            minimum: 2
> > > > +
> > > > +          adi,sensor-type:
> > > > +            description: Identifies the sensor as a rsense.
> > > > +            const: 29
> > > > +
> > > > +          adi,rsense-val-micro-ohms:
> > > > +            description: |
> > > > +              Sets the value of the sense resistor. Look at
> > > > table
> > > > 20 of the
> > > > +              datasheet for information.
> > > > +            allOf:
> > > > +              - $ref: /schemas/types.yaml#/definitions/uint64
> > > 
> > > -micro-ohms is already defined to be 32-bit.
> > 
> > I do need a 64-bit variable here. Should I still remove the $ref or
> > how
> > can I proceed?
> 
> We could add -milli-ohms. According to the datasheet, it's 0-131kohms
> in 1/1024ohm steps.

We will loose a bit of resolution, but I guess milli-ohms is more than
sufficient for practical/real usage.

> Rob
Nuno Sa Oct. 8, 2019, 10:22 a.m. UTC | #6
Hi Rob,

Somethings that I would like to clarify before sending a v4 since I'm
having errors and I'm not really sure about the fix I'm using.

On Tue, 2019-10-08 at 07:45 +0000, Sa, Nuno wrote:
> 
> On Mon, 2019-10-07 at 12:46 -0500, Rob Herring wrote:
> > On Mon, Oct 7, 2019 at 11:17 AM Sa, Nuno <Nuno.Sa@analog.com>
> > wrote:
> > > On Mon, 2019-10-07 at 09:45 -0500, Rob Herring wrote:
> > > > On Fri, Oct 4, 2019 at 8:55 AM Nuno Sá <nuno.sa@analog.com>
> > > > wrote:
> > > > > Document the LTC2983 temperature sensor devicetree bindings.
> > > > > 
> > > > > Signed-off-by: Nuno Sá <nuno.sa@analog.com>
> > > > > ---
> > > > > Changes in v2:
> > > > >  * Drop maxItems in non-array elements;
> > > > >  * Set adi,mux-delay-config-us instead of adi,mux-delay-
> > > > > config;
> > > > >  * Wrapped lines at 80 char;
> > > > >  * Added comas to enum elements;
> > > > >  * Use real units in adi,excitation-current;
> > > > >  * Moved some enums to minimum and maximum;
> > > > >  * Grouped patternProperties and moved reg property as a
> > > > > generic
> > > > > property.
> > > > > 
> > > > > Changes in v3:
> > > > >  * Add meaning to adi,sensor-type values which are not const;
> > > > >  * Add meaning to adi,filter-notch-freq values;
> > > > >  * Break up adi,sensor-config into human readable elements;
> > > > >  * Set maxItems/minItems at the same identation as allOf in
> > > > > adi,custom-sensor;
> > > > >  * Fixed the maximum value for adi,sensor-type for sensors
> > > > > with
> > > > > custom support;
> > > > >  * Changed license to GPL-2.0-only as it should be for new
> > > > > bindings;
> > > > >  * Changed spi0 to spi in the dts example;
> > > > >  * Updated the dts example to the new properties.
> > > > > 
> > > > >  .../bindings/iio/temperature/adi,ltc2983.yaml | 479
> > > > > ++++++++++++++++++
> > > > >  MAINTAINERS                                   |   1 +
> > > > >  2 files changed, 480 insertions(+)
> > > > >  create mode 100644
> > > > > Documentation/devicetree/bindings/iio/temperature/adi,ltc2983
> > > > > .y
> > > > > aml
> > > > > 
> > > > > diff --git
> > > > > a/Documentation/devicetree/bindings/iio/temperature/adi,ltc29
> > > > > 83
> > > > > .yam
> > > > > l
> > > > > b/Documentation/devicetree/bindings/iio/temperature/adi,ltc29
> > > > > 83
> > > > > .yam
> > > > > l
> > > > > new file mode 100644
> > > > > index 000000000000..b7101a0e84db
> > > > > --- /dev/null
> > > > > +++
> > > > > b/Documentation/devicetree/bindings/iio/temperature/adi,ltc29
> > > > > 83
> > > > > .yam
> > > > > l
> > > > > @@ -0,0 +1,479 @@
> > > > > +# SPDX-License-Identifier: GPL-2.0-only
> > > > 
> > > > (GPL-2.0-only OR BSD-2-Clause) for new bindings please.
> > > 
> > > ack.
> > > 
> > > > > +%YAML 1.2
> > > > > +---
> > > > > +$id:
> > > > > http://devicetree.org/schemas/iio/temperature/adi,ltc2983.yaml#
> > > > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > > > +
> > > > > +title: Analog Devices LTC2983 Multi-sensor Temperature
> > > > > system
> > > > > +
> > > > > +maintainers:
> > > > > +  - Nuno Sá <nuno.sa@analog.com>
> > > > > +
> > > > > +description: |
> > > > > +  Analog Devices LTC2983 Multi-Sensor Digital Temperature
> > > > > Measurement System
> > > > > +
> > > > > https://www.analog.com/media/en/technical-documentation/data-sheets/2983fc.pdf
> > > > > +
> > > > > +properties:
> > > > > +  compatible:
> > > > > +    enum:
> > > > > +      - adi,ltc2983
> > > > > +
> > > > > +  reg:
> > > > > +    maxItems: 1
> > > > > +
> > > > > +  interrupts:
> > > > > +    maxItems: 1
> > > > > +
> > > > > +  adi,temperature-celcius:
> > > > 
> > > > -celsius. However, that suffix is reserved for properties whose
> > > > value
> > > > is in Celsius, so you'll have to come up with something else.
> > > > 
> > > > How does one decide how to set this? Seems like the driver
> > > > should
> > > > just
> > > > decide based on what it needs to present to the user.
> > > 
> > > The device can report temperature in Celsius or Fahrenheit and
> > > that
> > > should be decided once. Hmm but now that I think about this, the
> > > iio
> > > standard attributes expect the value to be reported in milli
> > > degrees
> > > Celsius so I guess I should just drop this and don't report in
> > > Fahrenheit. Would this be ok Jonathan?
> > > 
> > > > > +    description:
> > > > > +      If this property is present, the temperature is
> > > > > reported
> > > > > in
> > > > > Celsius.
> > > > > +    type: boolean
> > > > > +
> > > > > +  adi,mux-delay-config-us:
> > > > > +    description:
> > > > > +      The LTC2983 performs 2 or 3 internal conversion cycles
> > > > > per
> > > > > temperature
> > > > > +      result. Each conversion cycle is performed with
> > > > > different
> > > > > excitation and
> > > > > +      input multiplexer configurations. Prior to each
> > > > > conversion,
> > > > > these
> > > > > +      excitation circuits and input switch configurations
> > > > > are
> > > > > changed and an
> > > > > +      internal 1ms delay ensures settling prior to the
> > > > > conversion
> > > > > cycle in most
> > > > > +      cases. An extra delay can be configured using this
> > > > > property.
> > > > > The value is
> > > > > +      rounded to nearest 100us.
> > > > > +    allOf:
> > > > > +      - $ref: /schemas/types.yaml#/definitions/uint32
> > > > > +      - maximum: 255
> > > > 
> > > > Standard unit suffixes already have a type, so just:
> > > > 
> > > > maximum: 255
> > > 
> > > got it.
> > > 
> > > > > +
> > > > > +  adi,filter-notch-freq:
> > > > > +    description:
> > > > > +      Set's the default setting of the digital filter. The
> > > > > default
> > > > > is
> > > > > +      simultaneous 50/60Hz rejection.
> > > > > +      0 - 50/60Hz rejection
> > > > > +      1 - 60Hz rejection
> > > > > +      2 - 50Hz rejection
> > > > > +    allOf:
> > > > > +      - $ref: /schemas/types.yaml#/definitions/uint32
> > > > > +      - minimum: 0
> > > > > +      - maximum: 2
> > > > 
> > > > Drop the '-' on the last entry (making the min/max a single
> > > > schema).
> > > 
> > > got it.
> > > 
> > > > > +
> > > > > +  '#address-cells':
> > > > > +    const: 1
> > > > > +
> > > > > +  '#size-cells':
> > > > > +    const: 0
> > > > > +
> > > > > +patternProperties:
> > > > > +  ".*@([1-9]|1[0-9]|20)$":
> > > > 
> > > > '.*' can be dropped.
> > > > 
> > > > > +    type: object
> > > > > +
> > > > > +    properties:
> > > > > +      reg:
> > > > > +        description: |
> > > > > +          The channel number. It can be connected to one of
> > > > > the 20
> > > > > channels of
> > > > > +          the device.
> > > > > +        minimum: 1
> > > > > +        maximum: 20
> > > > > +
> > > > > +    required:
> > > > > +      - reg
> > > > > +
> > > > > +    patternProperties:
> > > > > +      "^thermocouple@.*":
> > > > 
> > > > You've made this node a child of '.*@([1-9]|1[0-9]|20)$'. This
> > > > needs
> > > > to be at the same level.
> > > 
> > > You mean dropping "patternProperties" and having
> > > "^thermocouple@.*": on
> > > the same indent as ".*@([1-9]|1[0-9]|20)$":? It seems to be only
> > > one
> > 
> > Yes.
> > 
> > > working. I understood and tried something like:
> > > 
> > > patternProperties:
> > >   "@([1-9]|1[0-9]|20)$":
> > >    (...)
> > > 
> > >    patternProperties:
> > 
> > What you are saying here is you have a patternProperty called
> > 'patternProperty'.
> > 
> > >      "^thermocouple@.*"
> > 
> > And then this is not a valid json-schema keyword for the property's
> > schema.
> > 
> > >      description: "..."
> > >      type: object
> > >      properties:
> > >      (...)
> > > 
> > > But this throws "'^thermocouple@' is not one of ['$ref',
> > > 'additionalItems', 'additionalProperties', 'allOf', 'anyOf',
> > > 'const',
> > > 'contains', 'default', 'dependencies', 'deprecated',
> > > 'description',
> > > 'else', 'enum', 'items', 'if', 'minItems', 'minimum', 'maxItems',
> > > 'maximum', 'not', 'oneOf', 'pattern', 'patternProperties',
> > > 'properties', 'required', 'then', 'type', 'typeSize']"
> > > 
> > > Also, should I also drop the ".*" in "^thermocouple@.*"?
> > 
> > Yes.
> > 
> > > > > +        type: object
> > > > > +        description: |
> > > > 
> > > > You can drop the '|' where you don't need any formatting.
> > > 
> > > got it.
> > > 
> > > > > +          Represents a thermocouple sensor which is
> > > > > connected
> > > > > to
> > > > > one of the device
> > > > > +          channels.
> > > > > +
> > > > > +        properties:
> > > > > +          adi,sensor-type:
> > > > > +            description: |
> > > > > +              Identifies the type of thermocouple connected
> > > > > to
> > > > > the
> > > > > device.
> > > > > +              1 - Type J Thermocouple
> > > > > +              2 - Type K Thermocouple
> > > > > +              3 - Type E Thermocouple
> > > > > +              4 - Type N Thermocouple
> > > > > +              5 - Type R Thermocouple
> > > > > +              6 - Type S Thermocouple
> > > > > +              7 - Type T Thermocouple
> > > > > +              8 - Type B Thermocouple
> > > > > +              9 - Custom Thermocouple
> > > > > +            allOf:
> > > > > +              - $ref:
> > > > > /schemas/types.yaml#/definitions/uint32
> > > > 
> > > > You can move the type definition under ".*@([1-9]|1[0-9]|20)$"
> > > > and
> > > > then just have the min/max here.
> > > 
> > > And how could I add meaning to the values. Could I add all in the
> > > "parent" node?
> > 
> > No, they have to be at the correct level. You can keep the
> > descriptions here. Just do:
> > 
> > adi,sensor-type:
> >  description: ...
> >  $ref: /schemas/types.yaml#/definitions/uint32
> > 
> > under ".*@([1-9]|1[0-9]|20)$" and drop the 'allOf: [ $ref: ...]'
> > part.
> > 

So, Im doing like:

".*@([1-9]|1[0-9]|20)$":
  type: object

  properties:
    reg:
      description: ...
      minimum: 1
      maximum: 20
   
    adi,sensor-type:
      description: ...
      $ref: /schemas/types.yaml#/definitions/uint32
  
  required:
    - reg
    - adi,sensor-type

Then in:

"^thermocouple@":
  type: object
  description: ...
  
  properties:
    adi,sensor-type:
      description: ...
      minimum: 1
      maximum: 9
   
This gives me that adi,sensor-type is not a valid schema. Adding allOf
before min/max fixes it. The same error comes in:

"^diode@":
type: object
  description: ...
  
  properties:
    adi,sensor-type:
      description: ...
      const: 28 #adding allOf here also fixes it...

One last issue that I was not seeing before is with the reg property.
If you recall, you also suggested to have it under ".*@([1-9]|1[0-
9]|20)$": and then add the 'minimum: 2' where needed. Doing that now
also gives me invalid schema:

"^rtd@":
type: object
  description: ...

  properties:
    reg:
      minimum: 2

Changing to
    reg:
      items:
        minimum: 2

fixes it but it feels that the first one should work?
The other issue I have is with int64-matrix which for now i guess it's
expected...

I updated the dtschema with `pip3 install --upgrade git+
https://github.com/devicetree-org/dt-schema.git@master`

Thanks for your help!
Nuno Sá

> > > > > +              - minimum: 1
> > > > > +              - maximum: 9
> > > > > +
> > > > > +          adi,single-ended:
> > > > > +            description: |
> > > > > +              Boolean property which set's the thermocouple
> > > > > as
> > > > > single-ended.
> > > > > +            type: boolean
> > > > > +
> > > > > +          adi,sensor-oc-current-microamp:
> > > > > +            description: |
> > > > > +              This property set's the pulsed current value
> > > > > applied
> > > > > during
> > > > > +              open-circuit detect.
> > > > > +            allOf:
> > > > > +              - $ref:
> > > > > /schemas/types.yaml#/definitions/uint32
> > > > > +              - enum: [10, 100, 500, 1000]
> > > > > +
> > > > > +          adi,cold-junction-handle:
> > > > > +            description: |
> > > > > +              Phandle which points to a sensor object
> > > > > responsible
> > > > > for measuring
> > > > > +              the thermocouple cold junction temperature.
> > > > > +            $ref: "/schemas/types.yaml#/definitions/phandle"
> > > > > +
> > > > > +          adi,custom-sensor:
> > > > > +            description: |
> > > > > +              This is a table, where each entry should be a
> > > > > pair
> > > > > of
> > > > > +              voltage(mv)-temperature(K). The entries must
> > > > > be
> > > > > given in nv and uK
> > > > > +              so that, the original values must be
> > > > > multiplied
> > > > > by
> > > > > 1000000. For
> > > > 
> > > > We normally do things in microVolts. It seems strange to need
> > > > 64-
> > > > bits
> > > > of range for voltage and temperature.
> > > 
> > > This device support very high resolutions (so we have fractional
> > > values). That is why I'm multiplying by 1000000 and using nV. And
> > > even
> > > so, I already loose some bits. The 64bits are needed mainly
> > > because
> > > of
> > > the Temperature and again the resolution I want to maximize.
> > > Doing
> > > int(max(temp)) * 1000000, we need 64bits.
> > > 
> > > > > +              more details look at table 69 and 70.
> > > > > +            allOf:
> > > > > +              - $ref:
> > > > > /schemas/types.yaml#/definitions/int64-
> > > > > array
> > > > 
> > > > Fails on 'make dt_binding_check':
> > > > 
> > > > Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.y
> > > > am
> > > > l:
> > > > Unresolvable JSON pointer: 'definitions/int64-array'
> > > 
> > > I was aware of this but I do not know how to proceed so I was
> > > waiting
> > > for your comment. I do have negative values, so uint does not
> > > apply.
> > > What can I use here?
> > > 
> > > > If this is pairs of values, it should really be defined as a
> > > > matrix:
> > > > 
> > > > minItems: 3
> > > > maxItems: 64
> > > > items:
> > > >   minItems: 2
> > > >   maxItems: 2
> > > > 
> > > > Though I'll need to add uint64-matrix as a type (assuming this
> > > > really
> > > > needs to be 64-bit).
> > > 
> > > I reinforce that I do need signed values here.
> > 
> > I can add those as well. At least for now, they are going to end up
> > being the exact same definition because IIRC while dtc takes signed
> > input, that's lost by the time we emit the output.
> 
> So, can I just add something like int64-matrix?
> 
> > > > > +            minItems: 6
> > > > > +            maxItems: 128
> > > > > +
> > > > > +        required:
> > > > > +          - adi,sensor-type
> > > > > +
> > > > > +      "^diode@.*":
> > > > > +        type: object
> > > > > +        description: |
> > > > > +          Represents a diode sensor which is connected to
> > > > > one
> > > > > of
> > > > > the device
> > > > > +          channels.
> > > > > +
> > > > > +        properties:
> > > > > +          adi,sensor-type:
> > > > > +            description: Identifies the sensor as a diode.
> > > > > +            const: 28
> > > > > +
> > > > > +          adi,single-ended:
> > > > > +            description: Boolean property which set's the
> > > > > diode as
> > > > > single-ended.
> > > > > +            type: boolean
> > > > > +
> > > > > +          adi,three-conversion-cycles:
> > > > > +            description: |
> > > > > +              Boolean property which set's three conversion
> > > > > cycles
> > > > > removing
> > > > > +              parasitic resistance effects between the
> > > > > LTC2983
> > > > > and
> > > > > the diode.
> > > > > +            type: boolean
> > > > > +
> > > > > +          adi,average-on:
> > > > > +            description: |
> > > > > +              Boolean property which enables a running
> > > > > average
> > > > > of
> > > > > the diode
> > > > > +              temperature reading. This reduces the noise
> > > > > when
> > > > > the
> > > > > diode is used
> > > > > +              as a cold junction temperature element on an
> > > > > isothermal block
> > > > > +              where temperatures change slowly.
> > > > > +            type: boolean
> > > > > +
> > > > > +          adi,excitation-current-microamp:
> > > > > +            description: |
> > > > > +              This property controls the magnitude of the
> > > > > excitation current
> > > > > +              applied to the diode. Depending on the number
> > > > > of
> > > > > conversions
> > > > > +              cycles, this property will assume different
> > > > > predefined values on
> > > > > +              each cycle. Just set the value of the first
> > > > > cycle
> > > > > (1l).
> > > > > +            allOf:
> > > > > +              - $ref:
> > > > > /schemas/types.yaml#/definitions/uint32
> > > > > +              - enum: [10, 20, 40, 80]
> > > > > +
> > > > > +          adi,ideal-factor-value:
> > > > > +            description: |
> > > > > +              This property sets the diode ideality factor.
> > > > > The
> > > > > real value must
> > > > > +              be multiplied by 1000000 to remove the
> > > > > fractional
> > > > > part. For more
> > > > > +              information look at table 20 of the datasheet.
> > > > > +            allOf:
> > > > > +              - $ref:
> > > > > /schemas/types.yaml#/definitions/uint32
> > > > > +
> > > > > +        required:
> > > > > +          - adi,sensor-type
> > > > > +
> > > > > +      "^rtd@.*":
> > > > > +        type: object
> > > > > +        description: |
> > > > > +          Represents a rtd sensor which is connected to one
> > > > > of
> > > > > the
> > > > > device channels.
> > > > > +
> > > > > +        properties:
> > > > > +          reg:
> > > > > +            minimum: 2
> > > > > +
> > > > > +          adi,sensor-type:
> > > > > +            description: |
> > > > > +              Identifies the type of RTD connected to the
> > > > > device.
> > > > > +              10 - RTD PT-10
> > > > > +              11 - RTD PT-50
> > > > > +              12 - RTD PT-100
> > > > > +              13 - RTD PT-200
> > > > > +              14 - RTD PT-500
> > > > > +              15 - RTD PT-1000
> > > > > +              16 - RTD PT-1000 (0.00375)
> > > > > +              17 - RTD NI-120
> > > > > +              18 - RTD Custom
> > > > > +            allOf:
> > > > > +              - $ref:
> > > > > /schemas/types.yaml#/definitions/uint32
> > > > > +              - minimum: 10
> > > > > +              - maximum: 18
> > > > > +
> > > > > +          adi,rsense-handle:
> > > > > +            description: |
> > > > > +              Phandle pointing to a rsense object associated
> > > > > with
> > > > > this RTD.
> > > > > +            $ref: "/schemas/types.yaml#/definitions/phandle"
> > > > > +
> > > > > +          adi,number-of-wires:
> > > > > +            description: |
> > > > > +              Identifies the number of wires used by the
> > > > > RTD.
> > > > > Setting this
> > > > > +              property to 5 means 4 wires with Kelvin
> > > > > Rsense.
> > > > > +            allOf:
> > > > > +              - $ref:
> > > > > /schemas/types.yaml#/definitions/uint32
> > > > > +              - enum: [2, 3, 4, 5]
> > > > > +
> > > > > +          adi,rsense-share:
> > > > > +            description: |
> > > > > +              Boolean property which enables Rsense sharing,
> > > > > where
> > > > > one sense
> > > > > +              resistor is used for multiple 2-, 3-, and/or
> > > > > 4-
> > > > > wire
> > > > > RTDs.
> > > > > +            type: boolean
> > > > > +
> > > > > +          adi,current-rotate:
> > > > > +            description: |
> > > > > +              Boolean property which enables excitation
> > > > > current
> > > > > rotation to
> > > > > +              automatically remove parasitic thermocouple
> > > > > effects.
> > > > > Note that
> > > > > +              this property is not allowed for 2- and 3-wire
> > > > > RTDs.
> > > > > +            type: boolean
> > > > > +
> > > > > +          adi,excitation-current-microamp:
> > > > > +            description: |
> > > > > +              This property controls the magnitude of the
> > > > > excitation current
> > > > > +              applied to the RTD.
> > > > > +            allOf:
> > > > > +              - $ref:
> > > > > /schemas/types.yaml#/definitions/uint32
> > > > 
> > > > You can drop the type here too.
> > > 
> > > got it.
> > > 
> > > > > +              - enum: [5, 10, 25, 50, 100, 250, 500, 1000]
> > > > > +
> > > > > +          adi,rtd-curve:
> > > > > +            description: |
> > > > > +              This property set the RTD curve used and the
> > > > > corresponding
> > > > > +              Callendar-VanDusen constants. Look at table 30
> > > > > of
> > > > > the datasheet.
> > > > > +            allOf:
> > > > > +              - $ref:
> > > > > /schemas/types.yaml#/definitions/uint32
> > > > > +              - minimum: 0
> > > > > +              - maximum: 3
> > > > > +
> > > > > +          adi,custom-sensor:
> > > > > +            description: |
> > > > > +              This is a table, where each entry should be a
> > > > > pair
> > > > > of
> > > > > +              resistance(ohm)-temperature(K). The entries
> > > > > added
> > > > > here are in uohm
> > > > > +              and uK. For more details values look at table
> > > > > 74
> > > > > and
> > > > > 75.
> > > > 
> > > > It's not great to make one property name have different
> > > > meanings.
> > > 
> > > Would you prefer to have something like "custom-rtd", "custom-
> > > thermoucouple" and so on? I would have to adapt the code but I
> > > don't
> > > think it would need to much of a change.
> > 
> > I don't really know enough about this device to say... What does
> > 'custom' mean here?
> 
> Custom, is really if a user wants to provide a custom sensor, which
> is
> only supported for thermocouples, thermistors and RTDs. In those
> cases,
> the user provides a table of points describing the sensor response,
> which for example, on a thermocouple is voltage-temperature.
> 
> > > > > +            allOf:
> > > > > +              - $ref:
> > > > > /schemas/types.yaml#/definitions/uint64-
> > > > > array
> > > > > +            minItems: 6
> > > > > +            maxItems: 128
> > > > > +
> > > > > +        required:
> > > > > +          - adi,sensor-type
> > > > > +          - adi,rsense-handle
> > > > > +
> > > > > +        dependencies:
> > > > > +          adi,current-rotate: [ adi,rsense-share ]
> > > > > +
> > > > > +      "^thermistor@.*":
> > > > > +        type: object
> > > > > +        description: |
> > > > > +          Represents a thermistor sensor which is connected
> > > > > to
> > > > > one
> > > > > of the device
> > > > > +          channels.
> > > > > +
> > > > > +        properties:
> > > > > +          adi,sensor-type:
> > > > > +            description: |
> > > > > +              Identifies the type of thermistor connected to
> > > > > the
> > > > > +              device.
> > > > > +              19 - Thermistor 44004/44033 2.252kohm at 25°C
> > > > > +              20 - Thermistor 44005/44030 3kohm at 25°C
> > > > > +              21 - Thermistor 44007/44034 5kohm at 25°C
> > > > > +              22 - Thermistor 44006/44031 10kohm at 25°C
> > > > > +              23 - Thermistor 44008/44032 30kohm at 25°C
> > > > > +              24 - Thermistor YSI 400 2.252kohm at 25°C
> > > > > +              25 - Thermistor Spectrum 1003k 1kohm
> > > > > +              26 - Thermistor Custom Steinhart-Hart
> > > > > +              27 - Custom Thermistor
> > > > > +            allOf:
> > > > > +              - $ref:
> > > > > /schemas/types.yaml#/definitions/uint32
> > > > > +              - minimum: 19
> > > > > +              - maximum: 27
> > > > > +
> > > > > +          adi,rsense-handle:
> > > > > +            description: |
> > > > > +              Phandle pointing to a rsense object associated
> > > > > with
> > > > > this
> > > > > +              thermistor.
> > > > > +            $ref: "/schemas/types.yaml#/definitions/phandle"
> > > > > +
> > > > > +          adi,single-ended:
> > > > > +            description: |
> > > > > +              Boolean property which set's the thermistor as
> > > > > single-ended.
> > > > > +            type: boolean
> > > > > +
> > > > > +          adi,rsense-share:
> > > > > +            description: |
> > > > > +              Boolean property which enables Rsense sharing,
> > > > > where
> > > > > one sense
> > > > > +              resistor is used for multiple thermistors.
> > > > > Note
> > > > > that
> > > > > this property
> > > > > +              is ignored if adi,single-ended is set.
> > > > > +            type: boolean
> > > > > +
> > > > > +          adi,current-rotate:
> > > > > +            description: |
> > > > > +              Boolean property which enables excitation
> > > > > current
> > > > > rotation to
> > > > > +              automatically remove parasitic thermocouple
> > > > > effects.
> > > > > +            type: boolean
> > > > > +
> > > > > +          adi,excitation-current-nanoamp:
> > > > > +            description: |
> > > > > +              This property controls the magnitude of the
> > > > > excitation current
> > > > > +              applied to the thermistor. Value 0 set's the
> > > > > sensor
> > > > > in auto-range
> > > > > +              mode.
> > > > > +            allOf:
> > > > > +              - $ref:
> > > > > /schemas/types.yaml#/definitions/uint32
> > > > > +              - enum: [0, 250, 500, 1000, 5000, 10000,
> > > > > 25000,
> > > > > 50000, 100000,
> > > > > +                       250000, 500000, 1000000]
> > > > > +
> > > > > +          adi,custom-sensor:
> > > > > +            description: |
> > > > > +              This is a table, where each entry should be a
> > > > > pair
> > > > > of
> > > > > +              resistance(ohm)-temperature(K). The entries
> > > > > added
> > > > > here are in uohm
> > > > > +              and uK only for custom thermistors. For more
> > > > > details
> > > > > look at table
> > > > > +              78 and 79. Steinhart-Hart coefficients are
> > > > > also
> > > > > supported and can
> > > > > +              be programmed into the device memory using
> > > > > this
> > > > > property. For
> > > > > +              Steinhart sensors, this table has a constant
> > > > > size of
> > > > > 6 entries
> > > > > +              (defining the coefficients) and the values are
> > > > > given
> > > > > in the raw
> > > > > +              format. Look at table 82 for more information.
> > > > > +            allOf:
> > > > > +              - $ref:
> > > > > /schemas/types.yaml#/definitions/uint64-
> > > > > array
> > > > > +            minItems: 6
> > > > > +            maxItems: 128
> > > > > +
> > > 
> > > If I'm to replace this property as proposed before, would it make
> > > sense
> > > also to split this in custom-thermistor and custom-steinhart or
> > > just
> > > steinhart?
> > 
> > Seems like it as the data is completely different.
> 
> I'm also feeling like I should have this property split in 2.
> 
> > > > > +        required:
> > > > > +          - adi,sensor-type
> > > > > +          - adi,rsense-handle
> > > > > +
> > > > > +        dependencies:
> > > > > +          adi,current-rotate: [ adi,rsense-share ]
> > > > > +
> > > > > +      "^adc@.*":
> > > > > +        type: object
> > > > > +        description: Represents a channel which is being
> > > > > used
> > > > > as a
> > > > > direct adc.
> > > > > +
> > > > > +        properties:
> > > > > +          adi,sensor-type:
> > > > > +            description: Identifies the sensor as a direct
> > > > > adc.
> > > > > +            const: 30
> > > > > +
> > > > > +          adi,single-ended:
> > > > > +            description: Boolean property which set's the
> > > > > adc
> > > > > as
> > > > > single-ended.
> > > > > +            type: boolean
> > > > > +
> > > > > +        required:
> > > > > +          - adi,sensor-type
> > > > > +
> > > > > +      "^rsense@.*":
> > > > > +        type: object
> > > > > +        description: |
> > > > > +          Represents a rsense which is connected to one of
> > > > > the
> > > > > device channels.
> > > > > +          Rsense are used by thermistors and RTD's.
> > > > > +
> > > > > +        properties:
> > > > > +          reg:
> > > > > +            minimum: 2
> > > > > +
> > > > > +          adi,sensor-type:
> > > > > +            description: Identifies the sensor as a rsense.
> > > > > +            const: 29
> > > > > +
> > > > > +          adi,rsense-val-micro-ohms:
> > > > > +            description: |
> > > > > +              Sets the value of the sense resistor. Look at
> > > > > table
> > > > > 20 of the
> > > > > +              datasheet for information.
> > > > > +            allOf:
> > > > > +              - $ref:
> > > > > /schemas/types.yaml#/definitions/uint64
> > > > 
> > > > -micro-ohms is already defined to be 32-bit.
> > > 
> > > I do need a 64-bit variable here. Should I still remove the $ref
> > > or
> > > how
> > > can I proceed?
> > 
> > We could add -milli-ohms. According to the datasheet, it's 0-
> > 131kohms
> > in 1/1024ohm steps.
> 
> We will loose a bit of resolution, but I guess milli-ohms is more
> than
> sufficient for practical/real usage.
> 
> > Rob
Rob Herring (Arm) Oct. 10, 2019, 8:03 p.m. UTC | #7
On Tue, Oct 08, 2019 at 10:22:04AM +0000, Sa, Nuno wrote:
> Hi Rob,
> 
> Somethings that I would like to clarify before sending a v4 since I'm
> having errors and I'm not really sure about the fix I'm using.
> 
> On Tue, 2019-10-08 at 07:45 +0000, Sa, Nuno wrote:
> > 
> > On Mon, 2019-10-07 at 12:46 -0500, Rob Herring wrote:
> > > On Mon, Oct 7, 2019 at 11:17 AM Sa, Nuno <Nuno.Sa@analog.com>
> > > wrote:
> > > > On Mon, 2019-10-07 at 09:45 -0500, Rob Herring wrote:
> > > > > On Fri, Oct 4, 2019 at 8:55 AM Nuno Sá <nuno.sa@analog.com>
> > > > > wrote:
> > > > > > Document the LTC2983 temperature sensor devicetree bindings.
> > > > > > 
> > > > > > Signed-off-by: Nuno Sá <nuno.sa@analog.com>


> > > > > > +          Represents a thermocouple sensor which is
> > > > > > connected
> > > > > > to
> > > > > > one of the device
> > > > > > +          channels.
> > > > > > +
> > > > > > +        properties:
> > > > > > +          adi,sensor-type:
> > > > > > +            description: |
> > > > > > +              Identifies the type of thermocouple connected
> > > > > > to
> > > > > > the
> > > > > > device.
> > > > > > +              1 - Type J Thermocouple
> > > > > > +              2 - Type K Thermocouple
> > > > > > +              3 - Type E Thermocouple
> > > > > > +              4 - Type N Thermocouple
> > > > > > +              5 - Type R Thermocouple
> > > > > > +              6 - Type S Thermocouple
> > > > > > +              7 - Type T Thermocouple
> > > > > > +              8 - Type B Thermocouple
> > > > > > +              9 - Custom Thermocouple
> > > > > > +            allOf:
> > > > > > +              - $ref:
> > > > > > /schemas/types.yaml#/definitions/uint32
> > > > > 
> > > > > You can move the type definition under ".*@([1-9]|1[0-9]|20)$"
> > > > > and
> > > > > then just have the min/max here.
> > > > 
> > > > And how could I add meaning to the values. Could I add all in the
> > > > "parent" node?
> > > 
> > > No, they have to be at the correct level. You can keep the
> > > descriptions here. Just do:
> > > 
> > > adi,sensor-type:
> > >  description: ...
> > >  $ref: /schemas/types.yaml#/definitions/uint32
> > > 
> > > under ".*@([1-9]|1[0-9]|20)$" and drop the 'allOf: [ $ref: ...]'
> > > part.
> > > 
> 
> So, Im doing like:
> 
> ".*@([1-9]|1[0-9]|20)$":
>   type: object
> 
>   properties:
>     reg:
>       description: ...
>       minimum: 1
>       maximum: 20
>    
>     adi,sensor-type:
>       description: ...
>       $ref: /schemas/types.yaml#/definitions/uint32
>   
>   required:
>     - reg
>     - adi,sensor-type
> 
> Then in:
> 
> "^thermocouple@":
>   type: object
>   description: ...
>   
>   properties:
>     adi,sensor-type:
>       description: ...
>       minimum: 1
>       maximum: 9
>    
> This gives me that adi,sensor-type is not a valid schema. Adding allOf
> before min/max fixes it. The same error comes in:

Forget what I said, you're going to need to keep '$ref: 
/schemas/types.yaml#/definitions/uint32' here.

The problem is the meta-schema enforces that a vendor specific property 
(one with a comma) have a type defined and there's not really any way to 
say it already does elsewhere. I don't want to loosen that up globally 
either.

> 
> "^diode@":
> type: object
>   description: ...
>   
>   properties:
>     adi,sensor-type:
>       description: ...
>       const: 28 #adding allOf here also fixes it...

I need to fix the meta-schema to check what's under 'allOf'. :)

> 
> One last issue that I was not seeing before is with the reg property.
> If you recall, you also suggested to have it under ".*@([1-9]|1[0-
> 9]|20)$": and then add the 'minimum: 2' where needed. Doing that now
> also gives me invalid schema:
> 
> "^rtd@":
> type: object
>   description: ...
> 
>   properties:
>     reg:
>       minimum: 2
> 
> Changing to
>     reg:
>       items:
>         minimum: 2
> 
> fixes it but it feels that the first one should work?

The problem is we require both minimum and maximum to be defined. So 
really the second one should fail too. Or we should loosen this 
requirement.

Rob
Jonathan Cameron Oct. 12, 2019, 10:41 a.m. UTC | #8
On Mon, 7 Oct 2019 16:17:02 +0000
"Sa, Nuno" <Nuno.Sa@analog.com> wrote:

> On Mon, 2019-10-07 at 09:45 -0500, Rob Herring wrote:
> > On Fri, Oct 4, 2019 at 8:55 AM Nuno Sá <nuno.sa@analog.com> wrote:  
> > > Document the LTC2983 temperature sensor devicetree bindings.
> > > 
> > > Signed-off-by: Nuno Sá <nuno.sa@analog.com>
> > > ---
> > > Changes in v2:
> > >  * Drop maxItems in non-array elements;
> > >  * Set adi,mux-delay-config-us instead of adi,mux-delay-config;
> > >  * Wrapped lines at 80 char;
> > >  * Added comas to enum elements;
> > >  * Use real units in adi,excitation-current;
> > >  * Moved some enums to minimum and maximum;
> > >  * Grouped patternProperties and moved reg property as a generic
> > > property.
> > > 
> > > Changes in v3:
> > >  * Add meaning to adi,sensor-type values which are not const;
> > >  * Add meaning to adi,filter-notch-freq values;
> > >  * Break up adi,sensor-config into human readable elements;
> > >  * Set maxItems/minItems at the same identation as allOf in
> > > adi,custom-sensor;
> > >  * Fixed the maximum value for adi,sensor-type for sensors with
> > > custom support;
> > >  * Changed license to GPL-2.0-only as it should be for new
> > > bindings;
> > >  * Changed spi0 to spi in the dts example;
> > >  * Updated the dts example to the new properties.
> > > 
> > >  .../bindings/iio/temperature/adi,ltc2983.yaml | 479
> > > ++++++++++++++++++
> > >  MAINTAINERS                                   |   1 +
> > >  2 files changed, 480 insertions(+)
> > >  create mode 100644
> > > Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> > > 
> > > diff --git
> > > a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > > l
> > > b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > > l
> > > new file mode 100644
> > > index 000000000000..b7101a0e84db
> > > --- /dev/null
> > > +++
> > > b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > > l
> > > @@ -0,0 +1,479 @@
> > > +# SPDX-License-Identifier: GPL-2.0-only  
> > 
> > (GPL-2.0-only OR BSD-2-Clause) for new bindings please.  
> 
> ack.
> 
> > > +%YAML 1.2
> > > +---
> > > +$id: 
> > > http://devicetree.org/schemas/iio/temperature/adi,ltc2983.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: Analog Devices LTC2983 Multi-sensor Temperature system
> > > +
> > > +maintainers:
> > > +  - Nuno Sá <nuno.sa@analog.com>
> > > +
> > > +description: |
> > > +  Analog Devices LTC2983 Multi-Sensor Digital Temperature
> > > Measurement System
> > > +  
> > > https://www.analog.com/media/en/technical-documentation/data-sheets/2983fc.pdf
> > > +
> > > +properties:
> > > +  compatible:
> > > +    enum:
> > > +      - adi,ltc2983
> > > +
> > > +  reg:
> > > +    maxItems: 1
> > > +
> > > +  interrupts:
> > > +    maxItems: 1
> > > +
> > > +  adi,temperature-celcius:  
> > 
> > -celsius. However, that suffix is reserved for properties whose value
> > is in Celsius, so you'll have to come up with something else.
> > 
> > How does one decide how to set this? Seems like the driver should
> > just
> > decide based on what it needs to present to the user.  
> 
> The device can report temperature in Celsius or Fahrenheit and that
> should be decided once. Hmm but now that I think about this, the iio
> standard attributes expect the value to be reported in milli degrees
> Celsius so I guess I should just drop this and don't report in
> Fahrenheit. Would this be ok Jonathan?

Guessing you've already done this, but yes I'm fine with just not
supporting Fahrenheit at all.


> 
> > > +    description:
> > > +      If this property is present, the temperature is reported in
> > > Celsius.
> > > +    type: boolean
> > > +
> > > +  adi,mux-delay-config-us:
> > > +    description:
> > > +      The LTC2983 performs 2 or 3 internal conversion cycles per
> > > temperature
> > > +      result. Each conversion cycle is performed with different
> > > excitation and
> > > +      input multiplexer configurations. Prior to each conversion,
> > > these
> > > +      excitation circuits and input switch configurations are
> > > changed and an
> > > +      internal 1ms delay ensures settling prior to the conversion
> > > cycle in most
> > > +      cases. An extra delay can be configured using this property.
> > > The value is
> > > +      rounded to nearest 100us.
> > > +    allOf:
> > > +      - $ref: /schemas/types.yaml#/definitions/uint32
> > > +      - maximum: 255  
> > 
> > Standard unit suffixes already have a type, so just:
> > 
> > maximum: 255  
> 
> got it.
> 
> > > +
> > > +  adi,filter-notch-freq:
> > > +    description:
> > > +      Set's the default setting of the digital filter. The default
> > > is
> > > +      simultaneous 50/60Hz rejection.
> > > +      0 - 50/60Hz rejection
> > > +      1 - 60Hz rejection
> > > +      2 - 50Hz rejection
> > > +    allOf:
> > > +      - $ref: /schemas/types.yaml#/definitions/uint32
> > > +      - minimum: 0
> > > +      - maximum: 2  
> > 
> > Drop the '-' on the last entry (making the min/max a single schema).  
> 
> got it.
> 
> > > +
> > > +  '#address-cells':
> > > +    const: 1
> > > +
> > > +  '#size-cells':
> > > +    const: 0
> > > +
> > > +patternProperties:
> > > +  ".*@([1-9]|1[0-9]|20)$":  
> > 
> > '.*' can be dropped.
> >   
> > > +    type: object
> > > +
> > > +    properties:
> > > +      reg:
> > > +        description: |
> > > +          The channel number. It can be connected to one of the 20
> > > channels of
> > > +          the device.
> > > +        minimum: 1
> > > +        maximum: 20
> > > +
> > > +    required:
> > > +      - reg
> > > +
> > > +    patternProperties:
> > > +      "^thermocouple@.*":  
> > 
> > You've made this node a child of '.*@([1-9]|1[0-9]|20)$'. This needs
> > to be at the same level.  
> 
> You mean dropping "patternProperties" and having "^thermocouple@.*": on
> the same indent as ".*@([1-9]|1[0-9]|20)$":? It seems to be only one
> working. I understood and tried something like:
> 
> patternProperties:
>   "@([1-9]|1[0-9]|20)$":
>    (...)
>    
>    patternProperties:
>      "^thermocouple@.*"
>      description: "..."
>      type: object
>      properties:
>      (...)
> 
> But this throws "'^thermocouple@' is not one of ['$ref',
> 'additionalItems', 'additionalProperties', 'allOf', 'anyOf', 'const',
> 'contains', 'default', 'dependencies', 'deprecated', 'description',
> 'else', 'enum', 'items', 'if', 'minItems', 'minimum', 'maxItems',
> 'maximum', 'not', 'oneOf', 'pattern', 'patternProperties',
> 'properties', 'required', 'then', 'type', 'typeSize']"
> 
> Also, should I also drop the ".*" in "^thermocouple@.*"?
> > > +        type: object
> > > +        description: |  
> > 
> > You can drop the '|' where you don't need any formatting.  
> 
> got it.
> 
> > > +          Represents a thermocouple sensor which is connected to
> > > one of the device
> > > +          channels.
> > > +
> > > +        properties:
> > > +          adi,sensor-type:
> > > +            description: |
> > > +              Identifies the type of thermocouple connected to the
> > > device.
> > > +              1 - Type J Thermocouple
> > > +              2 - Type K Thermocouple
> > > +              3 - Type E Thermocouple
> > > +              4 - Type N Thermocouple
> > > +              5 - Type R Thermocouple
> > > +              6 - Type S Thermocouple
> > > +              7 - Type T Thermocouple
> > > +              8 - Type B Thermocouple
> > > +              9 - Custom Thermocouple
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint32  
> > 
> > You can move the type definition under ".*@([1-9]|1[0-9]|20)$" and
> > then just have the min/max here.  
> 
> And how could I add meaning to the values. Could I add all in the
> "parent" node?
> 
> > > +              - minimum: 1
> > > +              - maximum: 9
> > > +
> > > +          adi,single-ended:
> > > +            description: |
> > > +              Boolean property which set's the thermocouple as
> > > single-ended.
> > > +            type: boolean
> > > +
> > > +          adi,sensor-oc-current-microamp:
> > > +            description: |
> > > +              This property set's the pulsed current value applied
> > > during
> > > +              open-circuit detect.
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > +              - enum: [10, 100, 500, 1000]
> > > +
> > > +          adi,cold-junction-handle:
> > > +            description: |
> > > +              Phandle which points to a sensor object responsible
> > > for measuring
> > > +              the thermocouple cold junction temperature.
> > > +            $ref: "/schemas/types.yaml#/definitions/phandle"
> > > +
> > > +          adi,custom-sensor:
> > > +            description: |
> > > +              This is a table, where each entry should be a pair
> > > of
> > > +              voltage(mv)-temperature(K). The entries must be
> > > given in nv and uK
> > > +              so that, the original values must be multiplied by
> > > 1000000. For  
> > 
> > We normally do things in microVolts. It seems strange to need 64-bits
> > of range for voltage and temperature.  
> 
> This device support very high resolutions (so we have fractional
> values). That is why I'm multiplying by 1000000 and using nV. And even
> so, I already loose some bits. The 64bits are needed mainly because of
> the Temperature and again the resolution I want to maximize. Doing
> int(max(temp)) * 1000000, we need 64bits.
> 
> >   
> > > +              more details look at table 69 and 70.
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/int64-array  
> > 
> > Fails on 'make dt_binding_check':
> > 
> > Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml:
> > Unresolvable JSON pointer: 'definitions/int64-array'  
> 
> I was aware of this but I do not know how to proceed so I was waiting
> for your comment. I do have negative values, so uint does not apply.
> What can I use here?
> 
> > If this is pairs of values, it should really be defined as a matrix:
> > 
> > minItems: 3
> > maxItems: 64
> > items:
> >   minItems: 2
> >   maxItems: 2
> > 
> > Though I'll need to add uint64-matrix as a type (assuming this really
> > needs to be 64-bit).  
> 
> I reinforce that I do need signed values here.
> 
> >   
> > > +            minItems: 6
> > > +            maxItems: 128
> > > +
> > > +        required:
> > > +          - adi,sensor-type
> > > +
> > > +      "^diode@.*":
> > > +        type: object
> > > +        description: |
> > > +          Represents a diode sensor which is connected to one of
> > > the device
> > > +          channels.
> > > +
> > > +        properties:
> > > +          adi,sensor-type:
> > > +            description: Identifies the sensor as a diode.
> > > +            const: 28
> > > +
> > > +          adi,single-ended:
> > > +            description: Boolean property which set's the diode as
> > > single-ended.
> > > +            type: boolean
> > > +
> > > +          adi,three-conversion-cycles:
> > > +            description: |
> > > +              Boolean property which set's three conversion cycles
> > > removing
> > > +              parasitic resistance effects between the LTC2983 and
> > > the diode.
> > > +            type: boolean
> > > +
> > > +          adi,average-on:
> > > +            description: |
> > > +              Boolean property which enables a running average of
> > > the diode
> > > +              temperature reading. This reduces the noise when the
> > > diode is used
> > > +              as a cold junction temperature element on an
> > > isothermal block
> > > +              where temperatures change slowly.
> > > +            type: boolean
> > > +
> > > +          adi,excitation-current-microamp:
> > > +            description: |
> > > +              This property controls the magnitude of the
> > > excitation current
> > > +              applied to the diode. Depending on the number of
> > > conversions
> > > +              cycles, this property will assume different
> > > predefined values on
> > > +              each cycle. Just set the value of the first cycle
> > > (1l).
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > +              - enum: [10, 20, 40, 80]
> > > +
> > > +          adi,ideal-factor-value:
> > > +            description: |
> > > +              This property sets the diode ideality factor. The
> > > real value must
> > > +              be multiplied by 1000000 to remove the fractional
> > > part. For more
> > > +              information look at table 20 of the datasheet.
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > +
> > > +        required:
> > > +          - adi,sensor-type
> > > +
> > > +      "^rtd@.*":
> > > +        type: object
> > > +        description: |
> > > +          Represents a rtd sensor which is connected to one of the
> > > device channels.
> > > +
> > > +        properties:
> > > +          reg:
> > > +            minimum: 2
> > > +
> > > +          adi,sensor-type:
> > > +            description: |
> > > +              Identifies the type of RTD connected to the device.
> > > +              10 - RTD PT-10
> > > +              11 - RTD PT-50
> > > +              12 - RTD PT-100
> > > +              13 - RTD PT-200
> > > +              14 - RTD PT-500
> > > +              15 - RTD PT-1000
> > > +              16 - RTD PT-1000 (0.00375)
> > > +              17 - RTD NI-120
> > > +              18 - RTD Custom
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > +              - minimum: 10
> > > +              - maximum: 18
> > > +
> > > +          adi,rsense-handle:
> > > +            description: |
> > > +              Phandle pointing to a rsense object associated with
> > > this RTD.
> > > +            $ref: "/schemas/types.yaml#/definitions/phandle"
> > > +
> > > +          adi,number-of-wires:
> > > +            description: |
> > > +              Identifies the number of wires used by the RTD.
> > > Setting this
> > > +              property to 5 means 4 wires with Kelvin Rsense.
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > +              - enum: [2, 3, 4, 5]
> > > +
> > > +          adi,rsense-share:
> > > +            description: |
> > > +              Boolean property which enables Rsense sharing, where
> > > one sense
> > > +              resistor is used for multiple 2-, 3-, and/or 4-wire
> > > RTDs.
> > > +            type: boolean
> > > +
> > > +          adi,current-rotate:
> > > +            description: |
> > > +              Boolean property which enables excitation current
> > > rotation to
> > > +              automatically remove parasitic thermocouple effects.
> > > Note that
> > > +              this property is not allowed for 2- and 3-wire RTDs.
> > > +            type: boolean
> > > +
> > > +          adi,excitation-current-microamp:
> > > +            description: |
> > > +              This property controls the magnitude of the
> > > excitation current
> > > +              applied to the RTD.
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint32  
> > 
> > You can drop the type here too.  
> 
> got it.
> 
> > > +              - enum: [5, 10, 25, 50, 100, 250, 500, 1000]
> > > +
> > > +          adi,rtd-curve:
> > > +            description: |
> > > +              This property set the RTD curve used and the
> > > corresponding
> > > +              Callendar-VanDusen constants. Look at table 30 of
> > > the datasheet.
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > +              - minimum: 0
> > > +              - maximum: 3
> > > +
> > > +          adi,custom-sensor:
> > > +            description: |
> > > +              This is a table, where each entry should be a pair
> > > of
> > > +              resistance(ohm)-temperature(K). The entries added
> > > here are in uohm
> > > +              and uK. For more details values look at table 74 and
> > > 75.  
> > 
> > It's not great to make one property name have different meanings.  
> 
> Would you prefer to have something like "custom-rtd", "custom-
> thermoucouple" and so on? I would have to adapt the code but I don't
> think it would need to much of a change.
> 
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint64-
> > > array
> > > +            minItems: 6
> > > +            maxItems: 128
> > > +
> > > +        required:
> > > +          - adi,sensor-type
> > > +          - adi,rsense-handle
> > > +
> > > +        dependencies:
> > > +          adi,current-rotate: [ adi,rsense-share ]
> > > +
> > > +      "^thermistor@.*":
> > > +        type: object
> > > +        description: |
> > > +          Represents a thermistor sensor which is connected to one
> > > of the device
> > > +          channels.
> > > +
> > > +        properties:
> > > +          adi,sensor-type:
> > > +            description: |
> > > +              Identifies the type of thermistor connected to the
> > > +              device.
> > > +              19 - Thermistor 44004/44033 2.252kohm at 25°C
> > > +              20 - Thermistor 44005/44030 3kohm at 25°C
> > > +              21 - Thermistor 44007/44034 5kohm at 25°C
> > > +              22 - Thermistor 44006/44031 10kohm at 25°C
> > > +              23 - Thermistor 44008/44032 30kohm at 25°C
> > > +              24 - Thermistor YSI 400 2.252kohm at 25°C
> > > +              25 - Thermistor Spectrum 1003k 1kohm
> > > +              26 - Thermistor Custom Steinhart-Hart
> > > +              27 - Custom Thermistor
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > +              - minimum: 19
> > > +              - maximum: 27
> > > +
> > > +          adi,rsense-handle:
> > > +            description: |
> > > +              Phandle pointing to a rsense object associated with
> > > this
> > > +              thermistor.
> > > +            $ref: "/schemas/types.yaml#/definitions/phandle"
> > > +
> > > +          adi,single-ended:
> > > +            description: |
> > > +              Boolean property which set's the thermistor as
> > > single-ended.
> > > +            type: boolean
> > > +
> > > +          adi,rsense-share:
> > > +            description: |
> > > +              Boolean property which enables Rsense sharing, where
> > > one sense
> > > +              resistor is used for multiple thermistors. Note that
> > > this property
> > > +              is ignored if adi,single-ended is set.
> > > +            type: boolean
> > > +
> > > +          adi,current-rotate:
> > > +            description: |
> > > +              Boolean property which enables excitation current
> > > rotation to
> > > +              automatically remove parasitic thermocouple effects.
> > > +            type: boolean
> > > +
> > > +          adi,excitation-current-nanoamp:
> > > +            description: |
> > > +              This property controls the magnitude of the
> > > excitation current
> > > +              applied to the thermistor. Value 0 set's the sensor
> > > in auto-range
> > > +              mode.
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint32
> > > +              - enum: [0, 250, 500, 1000, 5000, 10000, 25000,
> > > 50000, 100000,
> > > +                       250000, 500000, 1000000]
> > > +
> > > +          adi,custom-sensor:
> > > +            description: |
> > > +              This is a table, where each entry should be a pair
> > > of
> > > +              resistance(ohm)-temperature(K). The entries added
> > > here are in uohm
> > > +              and uK only for custom thermistors. For more details
> > > look at table
> > > +              78 and 79. Steinhart-Hart coefficients are also
> > > supported and can
> > > +              be programmed into the device memory using this
> > > property. For
> > > +              Steinhart sensors, this table has a constant size of
> > > 6 entries
> > > +              (defining the coefficients) and the values are given
> > > in the raw
> > > +              format. Look at table 82 for more information.
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint64-
> > > array
> > > +            minItems: 6
> > > +            maxItems: 128
> > > +  
> 
> If I'm to replace this property as proposed before, would it make sense
> also to split this in custom-thermistor and custom-steinhart or just
> steinhart?
> 
> > > +        required:
> > > +          - adi,sensor-type
> > > +          - adi,rsense-handle
> > > +
> > > +        dependencies:
> > > +          adi,current-rotate: [ adi,rsense-share ]
> > > +
> > > +      "^adc@.*":
> > > +        type: object
> > > +        description: Represents a channel which is being used as a
> > > direct adc.
> > > +
> > > +        properties:
> > > +          adi,sensor-type:
> > > +            description: Identifies the sensor as a direct adc.
> > > +            const: 30
> > > +
> > > +          adi,single-ended:
> > > +            description: Boolean property which set's the adc as
> > > single-ended.
> > > +            type: boolean
> > > +
> > > +        required:
> > > +          - adi,sensor-type
> > > +
> > > +      "^rsense@.*":
> > > +        type: object
> > > +        description: |
> > > +          Represents a rsense which is connected to one of the
> > > device channels.
> > > +          Rsense are used by thermistors and RTD's.
> > > +
> > > +        properties:
> > > +          reg:
> > > +            minimum: 2
> > > +
> > > +          adi,sensor-type:
> > > +            description: Identifies the sensor as a rsense.
> > > +            const: 29
> > > +
> > > +          adi,rsense-val-micro-ohms:
> > > +            description: |
> > > +              Sets the value of the sense resistor. Look at table
> > > 20 of the
> > > +              datasheet for information.
> > > +            allOf:
> > > +              - $ref: /schemas/types.yaml#/definitions/uint64  
> > 
> > -micro-ohms is already defined to be 32-bit.  
>  
> I do need a 64-bit variable here. Should I still remove the $ref or how
> can I proceed?
> 
> > > +
> > > +        required:
> > > +          - adi,sensor-type
> > > +          - adi, rsense-val  
> > 
> > spurious space.  
> 
> got it.
> 
> > > +
> > > +required:
> > > +  - compatible
> > > +  - reg
> > > +  - interrupts
> > > +
> > > +examples:
> > > +  - |
> > > +    #include <dt-bindings/interrupt-controller/irq.h>
> > > +    spi {
> > > +        #address-cells = <1>;
> > > +        #size-cells = <0>;
> > > +
> > > +        sensor_ltc2983: ltc2983@0 {
> > > +                compatible = "adi,ltc2983";
> > > +                reg = <0>;
> > > +
> > > +                #address-cells = <1>;
> > > +                #size-cells = <0>;
> > > +
> > > +                adi,temperature-celcius;
> > > +                interrupts = <20 IRQ_TYPE_EDGE_RISING>;
> > > +                interrupt-parent = <&gpio>;
> > > +
> > > +                thermocouple@18 {
> > > +                        reg = <18>;
> > > +                        adi,sensor-type = <8>; //Type B
> > > +                        adi,sensor-oc-current-microamp = <10>;
> > > +                        adi,cold-junction-handle = <&diode5>;
> > > +                };
> > > +
> > > +                diode5: diode@5 {
> > > +                        reg = <5>;
> > > +                        adi,sensor-type = <28>;
> > > +                };
> > > +
> > > +                rsense2: rsense@2 {
> > > +                        reg = <2>;
> > > +                        adi,sensor-type = <29>;
> > > +                        adi,rsense-val-micro-ohms = /bits/ 64
> > > <1200000000>; //1.2Kohms
> > > +                };
> > > +
> > > +                rtd@14 {
> > > +                        reg = <14>;
> > > +                        adi,sensor-type = <15>; //PT1000
> > > +                        /*2-wire, internal gnd, no current
> > > rotation*/
> > > +                        adi,number-of-wires = <2>;
> > > +                        adi,rsense-share;
> > > +                        adi,excitation-current-microamp = <500>;
> > > +                        adi,rsense-handle = <&rsense2>;
> > > +                };
> > > +
> > > +                adc@10 {
> > > +                        reg = <10>;
> > > +                        adi,sensor-type = <30>;
> > > +                        adi,single-ended;
> > > +                };
> > > +
> > > +                thermistor@12 {
> > > +                        reg = <12>;
> > > +                        adi,sensor-type = <26>; //Steinhart
> > > +                        adi,rsense-handle = <&rsense2>;
> > > +                        adi,custom-sensor = /bits/ 64 <0x00F371EC
> > > 0x12345678
> > > +                                        0x2C0F8733 0x10018C66
> > > 0xA0FEACCD
> > > +                                        0x90021D99>; //6 entries
> > > +                };
> > > +
> > > +                thermocouple@20 {
> > > +                        reg = <20>;
> > > +                        adi,sensor-type = <9>; //custom
> > > thermocouple
> > > +                        adi,single-ended;
> > > +                        adi,custom-sensor = /bits/ 64
> > > +                                 <(-50220000) 0
> > > +                                  (-30200000) 99100000
> > > +                                  (-5300000) 135400000
> > > +                                  0 273150000
> > > +                                  40200000 361200000
> > > +                                  55300000 522100000
> > > +                                  88300000 720300000
> > > +                                  132200000 811200000
> > > +                                  188700000 922500000
> > > +                                  460400000 1000000000>; //10
> > > pairs
> > > +               };
> > > +
> > > +        };
> > > +    };
> > > +...
> > > diff --git a/MAINTAINERS b/MAINTAINERS
> > > index 14a256e785ca..f747a9dc27f5 100644
> > > --- a/MAINTAINERS
> > > +++ b/MAINTAINERS
> > > @@ -9497,6 +9497,7 @@ W:        
> > > http://ez.analog.com/community/linux-device-drivers
> > >  L:     linux-iio@vger.kernel.org
> > >  S:     Supported
> > >  F:     drivers/iio/temperature/ltc2983.c
> > > +F:     Documentation/devicetree/bindings/iio/temperature/adi,ltc29
> > > 83.yaml
> > > 
> > >  LTC4261 HARDWARE MONITOR DRIVER
> > >  M:     Guenter Roeck <linux@roeck-us.net>
> > > --
> > > 2.23.0
> > >   
>
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
new file mode 100644
index 000000000000..b7101a0e84db
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
@@ -0,0 +1,479 @@ 
+# SPDX-License-Identifier: GPL-2.0-only
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/temperature/adi,ltc2983.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices LTC2983 Multi-sensor Temperature system
+
+maintainers:
+  - Nuno Sá <nuno.sa@analog.com>
+
+description: |
+  Analog Devices LTC2983 Multi-Sensor Digital Temperature Measurement System
+  https://www.analog.com/media/en/technical-documentation/data-sheets/2983fc.pdf
+
+properties:
+  compatible:
+    enum:
+      - adi,ltc2983
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  adi,temperature-celcius:
+    description:
+      If this property is present, the temperature is reported in Celsius.
+    type: boolean
+
+  adi,mux-delay-config-us:
+    description:
+      The LTC2983 performs 2 or 3 internal conversion cycles per temperature
+      result. Each conversion cycle is performed with different excitation and
+      input multiplexer configurations. Prior to each conversion, these
+      excitation circuits and input switch configurations are changed and an
+      internal 1ms delay ensures settling prior to the conversion cycle in most
+      cases. An extra delay can be configured using this property. The value is
+      rounded to nearest 100us.
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32
+      - maximum: 255
+
+  adi,filter-notch-freq:
+    description:
+      Set's the default setting of the digital filter. The default is
+      simultaneous 50/60Hz rejection.
+      0 - 50/60Hz rejection
+      1 - 60Hz rejection
+      2 - 50Hz rejection
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32
+      - minimum: 0
+      - maximum: 2
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+patternProperties:
+  ".*@([1-9]|1[0-9]|20)$":
+    type: object
+
+    properties:
+      reg:
+        description: |
+          The channel number. It can be connected to one of the 20 channels of
+          the device.
+        minimum: 1
+        maximum: 20
+
+    required:
+      - reg
+
+    patternProperties:
+      "^thermocouple@.*":
+        type: object
+        description: |
+          Represents a thermocouple sensor which is connected to one of the device
+          channels.
+
+        properties:
+          adi,sensor-type:
+            description: |
+              Identifies the type of thermocouple connected to the device.
+              1 - Type J Thermocouple
+              2 - Type K Thermocouple
+              3 - Type E Thermocouple
+              4 - Type N Thermocouple
+              5 - Type R Thermocouple
+              6 - Type S Thermocouple
+              7 - Type T Thermocouple
+              8 - Type B Thermocouple
+              9 - Custom Thermocouple
+            allOf:
+              - $ref: /schemas/types.yaml#/definitions/uint32
+              - minimum: 1
+              - maximum: 9
+
+          adi,single-ended:
+            description: |
+              Boolean property which set's the thermocouple as single-ended.
+            type: boolean
+
+          adi,sensor-oc-current-microamp:
+            description: |
+              This property set's the pulsed current value applied during
+              open-circuit detect.
+            allOf:
+              - $ref: /schemas/types.yaml#/definitions/uint32
+              - enum: [10, 100, 500, 1000]
+
+          adi,cold-junction-handle:
+            description: |
+              Phandle which points to a sensor object responsible for measuring
+              the thermocouple cold junction temperature.
+            $ref: "/schemas/types.yaml#/definitions/phandle"
+
+          adi,custom-sensor:
+            description: |
+              This is a table, where each entry should be a pair of
+              voltage(mv)-temperature(K). The entries must be given in nv and uK
+              so that, the original values must be multiplied by 1000000. For
+              more details look at table 69 and 70.
+            allOf:
+              - $ref: /schemas/types.yaml#/definitions/int64-array
+            minItems: 6
+            maxItems: 128
+
+        required:
+          - adi,sensor-type
+
+      "^diode@.*":
+        type: object
+        description: |
+          Represents a diode sensor which is connected to one of the device
+          channels.
+
+        properties:
+          adi,sensor-type:
+            description: Identifies the sensor as a diode.
+            const: 28
+
+          adi,single-ended:
+            description: Boolean property which set's the diode as single-ended.
+            type: boolean
+
+          adi,three-conversion-cycles:
+            description: |
+              Boolean property which set's three conversion cycles removing
+              parasitic resistance effects between the LTC2983 and the diode.
+            type: boolean
+
+          adi,average-on:
+            description: |
+              Boolean property which enables a running average of the diode
+              temperature reading. This reduces the noise when the diode is used
+              as a cold junction temperature element on an isothermal block
+              where temperatures change slowly.
+            type: boolean
+
+          adi,excitation-current-microamp:
+            description: |
+              This property controls the magnitude of the excitation current
+              applied to the diode. Depending on the number of conversions
+              cycles, this property will assume different predefined values on
+              each cycle. Just set the value of the first cycle (1l).
+            allOf:
+              - $ref: /schemas/types.yaml#/definitions/uint32
+              - enum: [10, 20, 40, 80]
+
+          adi,ideal-factor-value:
+            description: |
+              This property sets the diode ideality factor. The real value must
+              be multiplied by 1000000 to remove the fractional part. For more
+              information look at table 20 of the datasheet.
+            allOf:
+              - $ref: /schemas/types.yaml#/definitions/uint32
+
+        required:
+          - adi,sensor-type
+
+      "^rtd@.*":
+        type: object
+        description: |
+          Represents a rtd sensor which is connected to one of the device channels.
+
+        properties:
+          reg:
+            minimum: 2
+
+          adi,sensor-type:
+            description: |
+              Identifies the type of RTD connected to the device.
+              10 - RTD PT-10
+              11 - RTD PT-50
+              12 - RTD PT-100
+              13 - RTD PT-200
+              14 - RTD PT-500
+              15 - RTD PT-1000
+              16 - RTD PT-1000 (0.00375)
+              17 - RTD NI-120
+              18 - RTD Custom
+            allOf:
+              - $ref: /schemas/types.yaml#/definitions/uint32
+              - minimum: 10
+              - maximum: 18
+
+          adi,rsense-handle:
+            description: |
+              Phandle pointing to a rsense object associated with this RTD.
+            $ref: "/schemas/types.yaml#/definitions/phandle"
+
+          adi,number-of-wires:
+            description: |
+              Identifies the number of wires used by the RTD. Setting this
+              property to 5 means 4 wires with Kelvin Rsense.
+            allOf:
+              - $ref: /schemas/types.yaml#/definitions/uint32
+              - enum: [2, 3, 4, 5]
+
+          adi,rsense-share:
+            description: |
+              Boolean property which enables Rsense sharing, where one sense
+              resistor is used for multiple 2-, 3-, and/or 4-wire RTDs.
+            type: boolean
+
+          adi,current-rotate:
+            description: |
+              Boolean property which enables excitation current rotation to
+              automatically remove parasitic thermocouple effects. Note that
+              this property is not allowed for 2- and 3-wire RTDs.
+            type: boolean
+
+          adi,excitation-current-microamp:
+            description: |
+              This property controls the magnitude of the excitation current
+              applied to the RTD.
+            allOf:
+              - $ref: /schemas/types.yaml#/definitions/uint32
+              - enum: [5, 10, 25, 50, 100, 250, 500, 1000]
+
+          adi,rtd-curve:
+            description: |
+              This property set the RTD curve used and the corresponding
+              Callendar-VanDusen constants. Look at table 30 of the datasheet.
+            allOf:
+              - $ref: /schemas/types.yaml#/definitions/uint32
+              - minimum: 0
+              - maximum: 3
+
+          adi,custom-sensor:
+            description: |
+              This is a table, where each entry should be a pair of
+              resistance(ohm)-temperature(K). The entries added here are in uohm
+              and uK. For more details values look at table 74 and 75.
+            allOf:
+              - $ref: /schemas/types.yaml#/definitions/uint64-array
+            minItems: 6
+            maxItems: 128
+
+        required:
+          - adi,sensor-type
+          - adi,rsense-handle
+
+        dependencies:
+          adi,current-rotate: [ adi,rsense-share ]
+
+      "^thermistor@.*":
+        type: object
+        description: |
+          Represents a thermistor sensor which is connected to one of the device
+          channels.
+
+        properties:
+          adi,sensor-type:
+            description: |
+              Identifies the type of thermistor connected to the
+              device.
+              19 - Thermistor 44004/44033 2.252kohm at 25°C
+              20 - Thermistor 44005/44030 3kohm at 25°C
+              21 - Thermistor 44007/44034 5kohm at 25°C
+              22 - Thermistor 44006/44031 10kohm at 25°C
+              23 - Thermistor 44008/44032 30kohm at 25°C
+              24 - Thermistor YSI 400 2.252kohm at 25°C
+              25 - Thermistor Spectrum 1003k 1kohm
+              26 - Thermistor Custom Steinhart-Hart
+              27 - Custom Thermistor
+            allOf:
+              - $ref: /schemas/types.yaml#/definitions/uint32
+              - minimum: 19
+              - maximum: 27
+
+          adi,rsense-handle:
+            description: |
+              Phandle pointing to a rsense object associated with this
+              thermistor.
+            $ref: "/schemas/types.yaml#/definitions/phandle"
+
+          adi,single-ended:
+            description: |
+              Boolean property which set's the thermistor as single-ended.
+            type: boolean
+
+          adi,rsense-share:
+            description: |
+              Boolean property which enables Rsense sharing, where one sense
+              resistor is used for multiple thermistors. Note that this property
+              is ignored if adi,single-ended is set.
+            type: boolean
+
+          adi,current-rotate:
+            description: |
+              Boolean property which enables excitation current rotation to
+              automatically remove parasitic thermocouple effects.
+            type: boolean
+
+          adi,excitation-current-nanoamp:
+            description: |
+              This property controls the magnitude of the excitation current
+              applied to the thermistor. Value 0 set's the sensor in auto-range
+              mode.
+            allOf:
+              - $ref: /schemas/types.yaml#/definitions/uint32
+              - enum: [0, 250, 500, 1000, 5000, 10000, 25000, 50000, 100000,
+                       250000, 500000, 1000000]
+
+          adi,custom-sensor:
+            description: |
+              This is a table, where each entry should be a pair of
+              resistance(ohm)-temperature(K). The entries added here are in uohm
+              and uK only for custom thermistors. For more details look at table
+              78 and 79. Steinhart-Hart coefficients are also supported and can
+              be programmed into the device memory using this property. For
+              Steinhart sensors, this table has a constant size of 6 entries
+              (defining the coefficients) and the values are given in the raw
+              format. Look at table 82 for more information.
+            allOf:
+              - $ref: /schemas/types.yaml#/definitions/uint64-array
+            minItems: 6
+            maxItems: 128
+
+        required:
+          - adi,sensor-type
+          - adi,rsense-handle
+
+        dependencies:
+          adi,current-rotate: [ adi,rsense-share ]
+
+      "^adc@.*":
+        type: object
+        description: Represents a channel which is being used as a direct adc.
+
+        properties:
+          adi,sensor-type:
+            description: Identifies the sensor as a direct adc.
+            const: 30
+
+          adi,single-ended:
+            description: Boolean property which set's the adc as single-ended.
+            type: boolean
+
+        required:
+          - adi,sensor-type
+
+      "^rsense@.*":
+        type: object
+        description: |
+          Represents a rsense which is connected to one of the device channels.
+          Rsense are used by thermistors and RTD's.
+
+        properties:
+          reg:
+            minimum: 2
+
+          adi,sensor-type:
+            description: Identifies the sensor as a rsense.
+            const: 29
+
+          adi,rsense-val-micro-ohms:
+            description: |
+              Sets the value of the sense resistor. Look at table 20 of the
+              datasheet for information.
+            allOf:
+              - $ref: /schemas/types.yaml#/definitions/uint64
+
+        required:
+          - adi,sensor-type
+          - adi, rsense-val
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        sensor_ltc2983: ltc2983@0 {
+                compatible = "adi,ltc2983";
+                reg = <0>;
+
+                #address-cells = <1>;
+                #size-cells = <0>;
+
+                adi,temperature-celcius;
+                interrupts = <20 IRQ_TYPE_EDGE_RISING>;
+                interrupt-parent = <&gpio>;
+
+                thermocouple@18 {
+                        reg = <18>;
+                        adi,sensor-type = <8>; //Type B
+                        adi,sensor-oc-current-microamp = <10>;
+                        adi,cold-junction-handle = <&diode5>;
+                };
+
+                diode5: diode@5 {
+                        reg = <5>;
+                        adi,sensor-type = <28>;
+                };
+
+                rsense2: rsense@2 {
+                        reg = <2>;
+                        adi,sensor-type = <29>;
+                        adi,rsense-val-micro-ohms = /bits/ 64 <1200000000>; //1.2Kohms
+                };
+
+                rtd@14 {
+                        reg = <14>;
+                        adi,sensor-type = <15>; //PT1000
+                        /*2-wire, internal gnd, no current rotation*/
+                        adi,number-of-wires = <2>;
+                        adi,rsense-share;
+                        adi,excitation-current-microamp = <500>;
+                        adi,rsense-handle = <&rsense2>;
+                };
+
+                adc@10 {
+                        reg = <10>;
+                        adi,sensor-type = <30>;
+                        adi,single-ended;
+                };
+
+                thermistor@12 {
+                        reg = <12>;
+                        adi,sensor-type = <26>; //Steinhart
+                        adi,rsense-handle = <&rsense2>;
+                        adi,custom-sensor = /bits/ 64 <0x00F371EC 0x12345678
+                                        0x2C0F8733 0x10018C66 0xA0FEACCD
+                                        0x90021D99>; //6 entries
+                };
+
+                thermocouple@20 {
+                        reg = <20>;
+                        adi,sensor-type = <9>; //custom thermocouple
+                        adi,single-ended;
+                        adi,custom-sensor = /bits/ 64
+                                 <(-50220000) 0
+                                  (-30200000) 99100000
+                                  (-5300000) 135400000
+                                  0 273150000
+                                  40200000 361200000
+                                  55300000 522100000
+                                  88300000 720300000
+                                  132200000 811200000
+                                  188700000 922500000
+                                  460400000 1000000000>; //10 pairs
+               };
+
+        };
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 14a256e785ca..f747a9dc27f5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9497,6 +9497,7 @@  W:	http://ez.analog.com/community/linux-device-drivers
 L:	linux-iio@vger.kernel.org
 S:	Supported
 F:	drivers/iio/temperature/ltc2983.c
+F:	Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
 
 LTC4261 HARDWARE MONITOR DRIVER
 M:	Guenter Roeck <linux@roeck-us.net>