| Message ID | 20220115092705.491-4-nuno.sa@analog.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | Add support for LTC2688 | expand |
On Sat, 15 Jan 2022 10:27:05 +0100 Nuno Sá <nuno.sa@analog.com> wrote: > Document the LTC2688 devicetree properties. > > Signed-off-by: Nuno Sá <nuno.sa@analog.com> Hi Nuno, A few minor comments inline. I've reviewed this first so might find answers to some of them when reading the driver code. Thanks, Jonathan > --- > .../bindings/iio/dac/adi,ltc2688.yaml | 147 ++++++++++++++++++ > MAINTAINERS | 1 + > 2 files changed, 148 insertions(+) > create mode 100644 Documentation/devicetree/bindings/iio/dac/adi,ltc2688.yaml > > diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ltc2688.yaml b/Documentation/devicetree/bindings/iio/dac/adi,ltc2688.yaml > new file mode 100644 > index 000000000000..ecd0943fb813 > --- /dev/null > +++ b/Documentation/devicetree/bindings/iio/dac/adi,ltc2688.yaml > @@ -0,0 +1,147 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/iio/dac/adi,ltc2688.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Analog Devices LTC2688 DAC > + > +maintainers: > + - Nuno Sá <nuno.sa@analog.com> > + > +description: | > + Analog Devices LTC2688 16 channel, 16 bit, +-15V DAC > + https://www.analog.com/media/en/technical-documentation/data-sheets/ltc2688.pdf > + > +properties: > + compatible: > + enum: > + - adi,ltc2688 > + > + reg: > + maxItems: 1 > + > + vcc-supply: > + description: Analog Supply Voltage Input. > + > + iovcc-supply: > + description: Digital Input/Output Supply Voltage. > + > + vref-supply: > + description: > + Reference Input/Output. The voltage at the REF pin sets the full-scale > + range of all channels. By default, the internal reference is routed to > + this pin. Perhaps "If not provided the internal reference is used and also provided on the VREF pin". > + > + clr-gpios: > + description: > + If specified, it will be asserted during driver probe. As the line is > + active low, it should be marked GPIO_ACTIVE_LOW. > + maxItems: 1 > + > + '#address-cells': > + const: 1 > + > + '#size-cells': > + const: 0 > + > +patternProperties: > + "^channel@([0-9]|1[0-5])$": > + type: object > + > + properties: > + reg: > + description: The channel number representing the DAC output channel. > + maximum: 15 > + > + adi,toggle-mode: > + description: > + Set the channel as a toggle enabled channel. Toggle operation enables > + fast switching of a DAC output between two different DAC codes without > + any SPI transaction. It will result in a different ABI for the > + channel. The ABI bit is a linux specific part so shouldn't be in the binding. Just leave it unsaid. > + type: boolean > + > + adi,output-range-microvolt: > + description: Specify the channel output full scale range. > + oneOf: > + - items: > + - const: 0 > + - enum: [5000000, 10000000] > + - items: > + - const: -5000000 > + - const: 5000000 > + - items: > + - const: -10000000 > + - const: 10000000 > + - items: > + - const: -15000000 > + - const: 15000000 Not necessarily a thing to do now, but this is common enough we should make it a standard DAC channel property. > + > + adi,overrange: > + description: Enable 5% overrange over the selected full scale range. > + type: boolean > + > + clocks: > + maxItems: 1 > + > + adi,toggle-dither-input: > + description: > + Selects the TGPx pin to be associated with this channel. This setting > + only makes sense for toggle or dither enabled channels. If > + @adi,toggle-mode is not set and this property is given, the channel is > + assumed to be a dither capable channel. Note that multiple channels > + can be mapped to the same pin. If this setting is given, the > + respective @clock must also be provided. Mappings between this and > + clocks That's not clear, mapping between this an input pin is probably more accurate? > + 0 - TGP1 > + 1 - TGP2 > + 2 - TGP3 > + $ref: /schemas/types.yaml#/definitions/uint32 > + enum: [0, 1, 2] > + > + dependencies: > + adi,toggle-dither-input: [ clocks ] > + > + required: > + - reg > + > +required: > + - compatible > + - reg > + > +additionalProperties: false > + > +examples: > + - | > + > + spi { > + #address-cells = <1>; > + #size-cells = <0>; > + ltc2688: ltc2688@0 { > + compatible = "adi,ltc2688"; > + reg = <0>; > + > + vcc-supply = <&vcc>; > + iovcc-supply = <&vcc>; > + vref-supply = <&vref>; > + > + #address-cells = <1>; > + #size-cells = <0>; > + channel@0 { > + reg = <0>; > + adi,toggle-mode; Can do this without adi,toggle-dither-input? > + adi,overrange; > + }; > + > + channel@1 { > + reg = <1>; > + adi,output-range-microvolt = <0 10000000>; > + > + clocks = <&clock_tgp3>; > + adi,toggle-dither-input = <2>; > + }; > + }; > + }; > + > +... > diff --git a/MAINTAINERS b/MAINTAINERS > index 16a7fd7f98ee..137d4ed992cf 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -11188,6 +11188,7 @@ L: linux-iio@vger.kernel.org > S: Supported > W: http://ez.analog.com/community/linux-device-drivers > F: Documentation/ABI/testing/sysfs-bus-iio-dac-ltc2688 > +F: Documentation/devicetree/bindings/iio/dac/adi,ltc2688.yaml > F: drivers/iio/dac/ltc2688.c > > LTC2947 HARDWARE MONITOR DRIVER
> -----Original Message----- > From: Jonathan Cameron <jic23@kernel.org> > Sent: Sunday, January 16, 2022 1:02 PM > To: Sa, Nuno <Nuno.Sa@analog.com> > Cc: linux-iio@vger.kernel.org; devicetree@vger.kernel.org; Rob > Herring <robh+dt@kernel.org>; Lars-Peter Clausen > <lars@metafoo.de>; Hennerich, Michael > <Michael.Hennerich@analog.com> > Subject: Re: [PATCH v2 3/3] dt-bindings: iio: Add ltc2688 > documentation > > [External] > > On Sat, 15 Jan 2022 10:27:05 +0100 > Nuno Sá <nuno.sa@analog.com> wrote: > > > Document the LTC2688 devicetree properties. > > > > Signed-off-by: Nuno Sá <nuno.sa@analog.com> > Hi Nuno, > > A few minor comments inline. I've reviewed this first so might > find answers to some of them when reading the driver code. > > Thanks, > > Jonathan > > > --- > > .../bindings/iio/dac/adi,ltc2688.yaml | 147 > ++++++++++++++++++ > > MAINTAINERS | 1 + > > 2 files changed, 148 insertions(+) > > create mode 100644 > Documentation/devicetree/bindings/iio/dac/adi,ltc2688.yaml > > > > diff --git > a/Documentation/devicetree/bindings/iio/dac/adi,ltc2688.yaml > b/Documentation/devicetree/bindings/iio/dac/adi,ltc2688.yaml > > new file mode 100644 > > index 000000000000..ecd0943fb813 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/iio/dac/adi,ltc2688.yaml > > @@ -0,0 +1,147 @@ > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > > +%YAML 1.2 > > +--- > > +$id: > https://urldefense.com/v3/__http://devicetree.org/schemas/iio/dac/ > adi,ltc2688.yaml*__;Iw!!A3Ni8CS0y2Y!qhcjFFDY939hv3Lo2iT1fAIbSObt > YscKoXjAnLgWZRNG6_WE2WXgZ8AdE4FUwg$ > > +$schema: > https://urldefense.com/v3/__http://devicetree.org/meta- > schemas/core.yaml*__;Iw!!A3Ni8CS0y2Y!qhcjFFDY939hv3Lo2iT1fAIbS > ObtYscKoXjAnLgWZRNG6_WE2WXgZ8BOzIvN9g$ > > + > > +title: Analog Devices LTC2688 DAC > > + > > +maintainers: > > + - Nuno Sá <nuno.sa@analog.com> > > + > > +description: | > > + Analog Devices LTC2688 16 channel, 16 bit, +-15V DAC > > + https://www.analog.com/media/en/technical- > documentation/data-sheets/ltc2688.pdf > > + > > +properties: > > + compatible: > > + enum: > > + - adi,ltc2688 > > + > > + reg: > > + maxItems: 1 > > + > > + vcc-supply: > > + description: Analog Supply Voltage Input. > > + > > + iovcc-supply: > > + description: Digital Input/Output Supply Voltage. > > + > > + vref-supply: > > + description: > > + Reference Input/Output. The voltage at the REF pin sets the full- > scale > > + range of all channels. By default, the internal reference is routed > to > > + this pin. > > Perhaps "If not provided the internal reference is used and also > provided on the > VREF pin". Sure... > > + > > + clr-gpios: > > + description: > > + If specified, it will be asserted during driver probe. As the line is > > + active low, it should be marked GPIO_ACTIVE_LOW. > > + maxItems: 1 > > + > > + '#address-cells': > > + const: 1 > > + > > + '#size-cells': > > + const: 0 > > + > > +patternProperties: > > + "^channel@([0-9]|1[0-5])$": > > + type: object > > + > > + properties: > > + reg: > > + description: The channel number representing the DAC output > channel. > > + maximum: 15 > > + > > + adi,toggle-mode: > > + description: > > + Set the channel as a toggle enabled channel. Toggle operation > enables > > + fast switching of a DAC output between two different DAC > codes without > > + any SPI transaction. It will result in a different ABI for the > > + channel. > > The ABI bit is a linux specific part so shouldn't be in the binding. Just > leave > it unsaid. Makes sense... > > + type: boolean > > + > > + adi,output-range-microvolt: > > + description: Specify the channel output full scale range. > > + oneOf: > > + - items: > > + - const: 0 > > + - enum: [5000000, 10000000] > > + - items: > > + - const: -5000000 > > + - const: 5000000 > > + - items: > > + - const: -10000000 > > + - const: 10000000 > > + - items: > > + - const: -15000000 > > + - const: 15000000 > > Not necessarily a thing to do now, but this is common enough we > should > make it a standard DAC channel property. > > > + > > + adi,overrange: > > + description: Enable 5% overrange over the selected full scale > range. > > + type: boolean > > + > > + clocks: > > + maxItems: 1 > > + > > + adi,toggle-dither-input: > > + description: > > + Selects the TGPx pin to be associated with this channel. This > setting > > + only makes sense for toggle or dither enabled channels. If > > + @adi,toggle-mode is not set and this property is given, the > channel is > > + assumed to be a dither capable channel. Note that multiple > channels > > + can be mapped to the same pin. If this setting is given, the > > + respective @clock must also be provided. Mappings between > this and > > + clocks > > That's not clear, mapping between this an input pin is probably more > accurate? Yeah, you're right. When I added this, I had the clock-names properties with these exact names. So, in the first version it was more acceptable but since I removed clock-names, this is not clear anymore... > > + 0 - TGP1 > > + 1 - TGP2 > > + 2 - TGP3 > > + $ref: /schemas/types.yaml#/definitions/uint32 > > + enum: [0, 1, 2] > > + > > + dependencies: > > + adi,toggle-dither-input: [ clocks ] > > + > > + required: > > + - reg > > + > > +required: > > + - compatible > > + - reg > > + > > +additionalProperties: false > > + > > +examples: > > + - | > > + > > + spi { > > + #address-cells = <1>; > > + #size-cells = <0>; > > + ltc2688: ltc2688@0 { > > + compatible = "adi,ltc2688"; > > + reg = <0>; > > + > > + vcc-supply = <&vcc>; > > + iovcc-supply = <&vcc>; > > + vref-supply = <&vref>; > > + > > + #address-cells = <1>; > > + #size-cells = <0>; > > + channel@0 { > > + reg = <0>; > > + adi,toggle-mode; > > Can do this without adi,toggle-dither-input? Yes, In this case it will assume SW toggle and expose the _symbol interface... - Nuno Sá
diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ltc2688.yaml b/Documentation/devicetree/bindings/iio/dac/adi,ltc2688.yaml new file mode 100644 index 000000000000..ecd0943fb813 --- /dev/null +++ b/Documentation/devicetree/bindings/iio/dac/adi,ltc2688.yaml @@ -0,0 +1,147 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/iio/dac/adi,ltc2688.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Analog Devices LTC2688 DAC + +maintainers: + - Nuno Sá <nuno.sa@analog.com> + +description: | + Analog Devices LTC2688 16 channel, 16 bit, +-15V DAC + https://www.analog.com/media/en/technical-documentation/data-sheets/ltc2688.pdf + +properties: + compatible: + enum: + - adi,ltc2688 + + reg: + maxItems: 1 + + vcc-supply: + description: Analog Supply Voltage Input. + + iovcc-supply: + description: Digital Input/Output Supply Voltage. + + vref-supply: + description: + Reference Input/Output. The voltage at the REF pin sets the full-scale + range of all channels. By default, the internal reference is routed to + this pin. + + clr-gpios: + description: + If specified, it will be asserted during driver probe. As the line is + active low, it should be marked GPIO_ACTIVE_LOW. + maxItems: 1 + + '#address-cells': + const: 1 + + '#size-cells': + const: 0 + +patternProperties: + "^channel@([0-9]|1[0-5])$": + type: object + + properties: + reg: + description: The channel number representing the DAC output channel. + maximum: 15 + + adi,toggle-mode: + description: + Set the channel as a toggle enabled channel. Toggle operation enables + fast switching of a DAC output between two different DAC codes without + any SPI transaction. It will result in a different ABI for the + channel. + type: boolean + + adi,output-range-microvolt: + description: Specify the channel output full scale range. + oneOf: + - items: + - const: 0 + - enum: [5000000, 10000000] + - items: + - const: -5000000 + - const: 5000000 + - items: + - const: -10000000 + - const: 10000000 + - items: + - const: -15000000 + - const: 15000000 + + adi,overrange: + description: Enable 5% overrange over the selected full scale range. + type: boolean + + clocks: + maxItems: 1 + + adi,toggle-dither-input: + description: + Selects the TGPx pin to be associated with this channel. This setting + only makes sense for toggle or dither enabled channels. If + @adi,toggle-mode is not set and this property is given, the channel is + assumed to be a dither capable channel. Note that multiple channels + can be mapped to the same pin. If this setting is given, the + respective @clock must also be provided. Mappings between this and + clocks + 0 - TGP1 + 1 - TGP2 + 2 - TGP3 + $ref: /schemas/types.yaml#/definitions/uint32 + enum: [0, 1, 2] + + dependencies: + adi,toggle-dither-input: [ clocks ] + + required: + - reg + +required: + - compatible + - reg + +additionalProperties: false + +examples: + - | + + spi { + #address-cells = <1>; + #size-cells = <0>; + ltc2688: ltc2688@0 { + compatible = "adi,ltc2688"; + reg = <0>; + + vcc-supply = <&vcc>; + iovcc-supply = <&vcc>; + vref-supply = <&vref>; + + #address-cells = <1>; + #size-cells = <0>; + channel@0 { + reg = <0>; + adi,toggle-mode; + adi,overrange; + }; + + channel@1 { + reg = <1>; + adi,output-range-microvolt = <0 10000000>; + + clocks = <&clock_tgp3>; + adi,toggle-dither-input = <2>; + }; + }; + }; + +... diff --git a/MAINTAINERS b/MAINTAINERS index 16a7fd7f98ee..137d4ed992cf 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11188,6 +11188,7 @@ L: linux-iio@vger.kernel.org S: Supported W: http://ez.analog.com/community/linux-device-drivers F: Documentation/ABI/testing/sysfs-bus-iio-dac-ltc2688 +F: Documentation/devicetree/bindings/iio/dac/adi,ltc2688.yaml F: drivers/iio/dac/ltc2688.c LTC2947 HARDWARE MONITOR DRIVER
Document the LTC2688 devicetree properties. Signed-off-by: Nuno Sá <nuno.sa@analog.com> --- .../bindings/iio/dac/adi,ltc2688.yaml | 147 ++++++++++++++++++ MAINTAINERS | 1 + 2 files changed, 148 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/dac/adi,ltc2688.yaml