| Message ID | 20210703173456.4002549-1-linus.walleij@linaro.org (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | [v2] dt-bindings: hwmon: Convert NTC thermistor to YAML | expand |
On Sat, Jul 03, 2021 at 07:34:56PM +0200, Linus Walleij wrote: > This converts the NTC thermistor DT bindings to YAML. Some care had to > be taken since I had to add some illustrations to make the connection > layouts graspable. > > Cc: Javier Martinez Canillas <javier@dowhile0.org> > Cc: Johannes Pointner <johannes.pointner@gmail.com> > Cc: Peter Rosin <peda@axentia.se> > Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> > Cc: devicetree@vger.kernel.org > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> > --- > ChangeLog v1->v2: > - Realize I need to CC devicetree@vger.kernel.org on this. > - Fix Javier's mail address. > - Drop Naveen's mail (bouncing) > --- > .../bindings/hwmon/ntc-thermistor.yaml | 142 ++++++++++++++++++ > .../bindings/hwmon/ntc_thermistor.txt | 44 ------ > 2 files changed, 142 insertions(+), 44 deletions(-) > create mode 100644 Documentation/devicetree/bindings/hwmon/ntc-thermistor.yaml > delete mode 100644 Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt > > diff --git a/Documentation/devicetree/bindings/hwmon/ntc-thermistor.yaml b/Documentation/devicetree/bindings/hwmon/ntc-thermistor.yaml > new file mode 100644 > index 000000000000..87589da631c9 > --- /dev/null > +++ b/Documentation/devicetree/bindings/hwmon/ntc-thermistor.yaml > @@ -0,0 +1,142 @@ > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) > +--- > +$id: http://devicetree.org/schemas/hwmon/ntc-thermistor.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: NTC thermistor temperature sensors > + > +maintainers: > + - Naveen Krishna Chatradhi <ch.naveen@samsung.com> > + - Linus Walleij <linus.walleij@linaro.org> > + > +description: | > + Thermistors with negative temperature coefficient (NTC) are resistors that > + vary in resistance in an often non-linear way in relation to temperature. > + The negative temperature coefficient means that the resistance decreases > + as the temperature rises. Since the relationship between resistance and > + temperature is non-linear, software drivers most often need to use a look > + up table and interpolation to get from resistance to temperature. > + > + When used in practice, a thermistor is often connected between ground, a > + pull-up resistor or/and a pull-down resistor and a fixed voltage like this: > + > + + e.g. 5V = pull-up voltage (puv) > + | > + +-+ > + | | > + | | Pull-up resistor > + | | (puo) > + +-+ > + |-------------------------o > + +-+ | ^ > + | |/ | > + | / | > + |/| Thermistor | Measured voltage (mv) > + / | | "connected ground" > + /| | | > + +-+ | > + |-------------------------o > + +-+ ^ > + | | | > + | | Pull-down resistor | Measured voltage (mv) > + | | (pdo) | "connected positive" > + +-+ | > + | | > + | v > + + GND GND > + > + The arrangements of where we measure the voltage over the thermistor are > + called "connected ground" and "connected positive" and shall be understood as > + the cases when either pull-up or pull-down resistance is zero. > + > + If the pull-up resistance is 0 one end of the thermistor is connected to the > + positive voltage and we get the thermistor on top of a pull-down resistor > + and we take the measure between the thermistor and the pull-down resistor. > + > + Conversely if the pull-down resistance is zero, one end of the thermistor is > + connected to ground and we get the thermistor under the pull-up resistor > + and we take the measure between the pull-up resistor and the thermistor. > + > + We can use both pull-up and pull-down resistors at the same time, and then > + the figure illustrates where the voltage will be measured for the "connected > + ground" and "connected positive" cases. > + > +properties: > + $nodename: > + pattern: "^thermistor(.*)?$" > + > + compatible: > + oneOf: > + - const: epcos,b57330v2103 > + - const: epcos,b57891s0103 > + - const: murata,ncp15wb473 > + - const: murata,ncp18wb473 > + - const: murata,ncp21wb473 > + - const: murata,ncp03wb473 > + - const: murata,ncp15wl333 > + - const: murata,ncp03wf104 > + - const: murata,ncp15xh103 All these can be 1 enum. > + # Deprecated "ntp," compatible strings > + - const: ntc,ncp15wb473 > + deprecated: true > + - const: ntc,ncp18wb473 > + deprecated: true > + - const: ntc,ncp21wb473 > + deprecated: true > + - const: ntc,ncp03wb473 > + deprecated: true > + - const: ntc,ncp15wl333 > + deprecated: true And these too. > + > + # See /schemas/thermal/thermal-sensor.yaml for details Drop. (I hope to generate documentation from the schema and automagically create references/links.) > + "#thermal-sensor-cells": > + description: Thermal sensor cells if used for thermal sensoring. > + const: 0 > + > + pullup-uv: > + $ref: /schemas/types.yaml#/definitions/uint32 > + description: Pull-up voltage in micro volts. Must always be specified. > + > + pullup-ohm: > + $ref: /schemas/types.yaml#/definitions/uint32 > + description: Pull-up resistance in ohms. Must always be specified, even > + if zero. > + > + pulldown-ohm: > + $ref: /schemas/types.yaml#/definitions/uint32 > + description: Pull-down resistance in ohms. Must always be specified, even > + if zero. > + > + connected-positive: > + $ref: /schemas/types.yaml#/definitions/flag > + description: Indicates how the thermistor is connected in series with > + a pull-up and/or a pull-down resistor. See the description above for > + an illustration. If this flag is NOT specified, the thermistor is assumed > + to be connected-ground, which usually means a pull-down resistance of > + zero but complex arrangements are possible. > + > + # See /schemas/iio/adc/adc.yaml > + io-channels: > + maxItems: 1 > + description: IIO ADC channel to read the voltage over the resistor. Must > + always be specified. > + > +required: > + - compatible > + - pullup-uv > + - pullup-ohm > + - pulldown-ohm > + - io-channels > + > +additionalProperties: false > + > +examples: > + - | > + thermistor0 { > + compatible = "murata,ncp18wb473"; > + io-channels = <&gpadc 0x06>; > + pullup-uv = <1800000>; > + pullup-ohm = <220000>; > + pulldown-ohm = <0>; > + #thermal-sensor-cells = <0>; > + };
On Mon, Jul 12, 2021 at 4:57 PM Rob Herring <robh@kernel.org> wrote: > On Sat, Jul 03, 2021 at 07:34:56PM +0200, Linus Walleij wrote: > > + compatible: > > + oneOf: > > + - const: epcos,b57330v2103 > > + - const: epcos,b57891s0103 > > + - const: murata,ncp15wb473 > > + - const: murata,ncp18wb473 > > + - const: murata,ncp21wb473 > > + - const: murata,ncp03wb473 > > + - const: murata,ncp15wl333 > > + - const: murata,ncp03wf104 > > + - const: murata,ncp15xh103 > > All these can be 1 enum. Yes that works fine. > > + # Deprecated "ntp," compatible strings > > + - const: ntc,ncp15wb473 > > + deprecated: true > > + - const: ntc,ncp18wb473 > > + deprecated: true > > + - const: ntc,ncp21wb473 > > + deprecated: true > > + - const: ntc,ncp03wb473 > > + deprecated: true > > + - const: ntc,ncp15wl333 > > + deprecated: true > > And these too. How? I'm lost here. This: compatible: enum: - epcos,b57330v2103 - epcos,b57891s0103 - murata,ncp15wb473 - murata,ncp18wb473 - murata,ncp21wb473 - murata,ncp03wb473 - murata,ncp15wl333 - murata,ncp03wf104 - murata,ncp15xh103 # Deprecated "ntp," compatible strings - ntc,ncp15wb473 deprecated: true - ntc,ncp18wb473 deprecated: true - ntc,ncp21wb473 deprecated: true - ntc,ncp03wb473 deprecated: true - ntc,ncp15wl333 deprecated: true Yields this: uamel.yaml.scanner.ScannerError: mapping values are not allowed here in "<unicode string>", line 81, column 19: deprecated: true ^ (line: 81) make[3]: *** [../Documentation/devicetree/bindings/Makefile:20: Documentation/devicetree/bindings/hwmon/ntc-thermistor.example.dts] Error 1 make[3]: *** Deleting file 'Documentation/devicetree/bindings/hwmon/ntc-thermistor.example.dts' ../Documentation/devicetree/bindings/hwmon/ntc-thermistor.yaml:81:19: [error] syntax error: mapping values are not allowed here (syntax) This does not happen with oneOf const:s. Yours, Linus Walleij
diff --git a/Documentation/devicetree/bindings/hwmon/ntc-thermistor.yaml b/Documentation/devicetree/bindings/hwmon/ntc-thermistor.yaml new file mode 100644 index 000000000000..87589da631c9 --- /dev/null +++ b/Documentation/devicetree/bindings/hwmon/ntc-thermistor.yaml @@ -0,0 +1,142 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) +--- +$id: http://devicetree.org/schemas/hwmon/ntc-thermistor.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: NTC thermistor temperature sensors + +maintainers: + - Naveen Krishna Chatradhi <ch.naveen@samsung.com> + - Linus Walleij <linus.walleij@linaro.org> + +description: | + Thermistors with negative temperature coefficient (NTC) are resistors that + vary in resistance in an often non-linear way in relation to temperature. + The negative temperature coefficient means that the resistance decreases + as the temperature rises. Since the relationship between resistance and + temperature is non-linear, software drivers most often need to use a look + up table and interpolation to get from resistance to temperature. + + When used in practice, a thermistor is often connected between ground, a + pull-up resistor or/and a pull-down resistor and a fixed voltage like this: + + + e.g. 5V = pull-up voltage (puv) + | + +-+ + | | + | | Pull-up resistor + | | (puo) + +-+ + |-------------------------o + +-+ | ^ + | |/ | + | / | + |/| Thermistor | Measured voltage (mv) + / | | "connected ground" + /| | | + +-+ | + |-------------------------o + +-+ ^ + | | | + | | Pull-down resistor | Measured voltage (mv) + | | (pdo) | "connected positive" + +-+ | + | | + | v + + GND GND + + The arrangements of where we measure the voltage over the thermistor are + called "connected ground" and "connected positive" and shall be understood as + the cases when either pull-up or pull-down resistance is zero. + + If the pull-up resistance is 0 one end of the thermistor is connected to the + positive voltage and we get the thermistor on top of a pull-down resistor + and we take the measure between the thermistor and the pull-down resistor. + + Conversely if the pull-down resistance is zero, one end of the thermistor is + connected to ground and we get the thermistor under the pull-up resistor + and we take the measure between the pull-up resistor and the thermistor. + + We can use both pull-up and pull-down resistors at the same time, and then + the figure illustrates where the voltage will be measured for the "connected + ground" and "connected positive" cases. + +properties: + $nodename: + pattern: "^thermistor(.*)?$" + + compatible: + oneOf: + - const: epcos,b57330v2103 + - const: epcos,b57891s0103 + - const: murata,ncp15wb473 + - const: murata,ncp18wb473 + - const: murata,ncp21wb473 + - const: murata,ncp03wb473 + - const: murata,ncp15wl333 + - const: murata,ncp03wf104 + - const: murata,ncp15xh103 + # Deprecated "ntp," compatible strings + - const: ntc,ncp15wb473 + deprecated: true + - const: ntc,ncp18wb473 + deprecated: true + - const: ntc,ncp21wb473 + deprecated: true + - const: ntc,ncp03wb473 + deprecated: true + - const: ntc,ncp15wl333 + deprecated: true + + # See /schemas/thermal/thermal-sensor.yaml for details + "#thermal-sensor-cells": + description: Thermal sensor cells if used for thermal sensoring. + const: 0 + + pullup-uv: + $ref: /schemas/types.yaml#/definitions/uint32 + description: Pull-up voltage in micro volts. Must always be specified. + + pullup-ohm: + $ref: /schemas/types.yaml#/definitions/uint32 + description: Pull-up resistance in ohms. Must always be specified, even + if zero. + + pulldown-ohm: + $ref: /schemas/types.yaml#/definitions/uint32 + description: Pull-down resistance in ohms. Must always be specified, even + if zero. + + connected-positive: + $ref: /schemas/types.yaml#/definitions/flag + description: Indicates how the thermistor is connected in series with + a pull-up and/or a pull-down resistor. See the description above for + an illustration. If this flag is NOT specified, the thermistor is assumed + to be connected-ground, which usually means a pull-down resistance of + zero but complex arrangements are possible. + + # See /schemas/iio/adc/adc.yaml + io-channels: + maxItems: 1 + description: IIO ADC channel to read the voltage over the resistor. Must + always be specified. + +required: + - compatible + - pullup-uv + - pullup-ohm + - pulldown-ohm + - io-channels + +additionalProperties: false + +examples: + - | + thermistor0 { + compatible = "murata,ncp18wb473"; + io-channels = <&gpadc 0x06>; + pullup-uv = <1800000>; + pullup-ohm = <220000>; + pulldown-ohm = <0>; + #thermal-sensor-cells = <0>; + }; diff --git a/Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt b/Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt deleted file mode 100644 index 4c5c3712970e..000000000000 --- a/Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt +++ /dev/null @@ -1,44 +0,0 @@ -NTC Thermistor hwmon sensors -------------------------------- - -Requires node properties: -- "compatible" value : one of - "epcos,b57330v2103" - "epcos,b57891s0103" - "murata,ncp15wb473" - "murata,ncp18wb473" - "murata,ncp21wb473" - "murata,ncp03wb473" - "murata,ncp15wl333" - "murata,ncp03wf104" - "murata,ncp15xh103" - -/* Usage of vendor name "ntc" is deprecated */ -<DEPRECATED> "ntc,ncp15wb473" -<DEPRECATED> "ntc,ncp18wb473" -<DEPRECATED> "ntc,ncp21wb473" -<DEPRECATED> "ntc,ncp03wb473" -<DEPRECATED> "ntc,ncp15wl333" - -- "pullup-uv" Pull up voltage in micro volts -- "pullup-ohm" Pull up resistor value in ohms -- "pulldown-ohm" Pull down resistor value in ohms -- "connected-positive" Always ON, If not specified. - Status change is possible. -- "io-channels" Channel node of ADC to be used for - conversion. - -Optional node properties: -- "#thermal-sensor-cells" Used to expose itself to thermal fw. - -Read more about iio bindings at - https://github.com/devicetree-org/dt-schema/blob/master/schemas/iio/ - -Example: - ncp15wb473@0 { - compatible = "murata,ncp15wb473"; - pullup-uv = <1800000>; - pullup-ohm = <47000>; - pulldown-ohm = <0>; - io-channels = <&adc 3>; - };
This converts the NTC thermistor DT bindings to YAML. Some care had to be taken since I had to add some illustrations to make the connection layouts graspable. Cc: Javier Martinez Canillas <javier@dowhile0.org> Cc: Johannes Pointner <johannes.pointner@gmail.com> Cc: Peter Rosin <peda@axentia.se> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: devicetree@vger.kernel.org Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- ChangeLog v1->v2: - Realize I need to CC devicetree@vger.kernel.org on this. - Fix Javier's mail address. - Drop Naveen's mail (bouncing) --- .../bindings/hwmon/ntc-thermistor.yaml | 142 ++++++++++++++++++ .../bindings/hwmon/ntc_thermistor.txt | 44 ------ 2 files changed, 142 insertions(+), 44 deletions(-) create mode 100644 Documentation/devicetree/bindings/hwmon/ntc-thermistor.yaml delete mode 100644 Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt