On Sat, 15 Jan 2022 10:27:05 +0100 Nuno Sá <nuno.sa@xxxxxxxxxx> wrote: > Document the LTC2688 devicetree properties. > > Signed-off-by: Nuno Sá <nuno.sa@xxxxxxxxxx> 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@xxxxxxxxxx> > + > +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@xxxxxxxxxxxxxxx > 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
