On Wed, Dec 13, 2023 at 10:09:09AM +0100, Mike Looijmans wrote: > Add a driver for generic serial shift register DACs like TI DAC714. This is not a driver. > > Signed-off-by: Mike Looijmans <mike.looijmans@xxxxxxxx> > > --- > > .../devicetree/bindings/iio/dac/spidac.yaml | 69 +++++++++++++++++++ > 1 file changed, 69 insertions(+) > create mode 100644 Documentation/devicetree/bindings/iio/dac/spidac.yaml > > diff --git a/Documentation/devicetree/bindings/iio/dac/spidac.yaml b/Documentation/devicetree/bindings/iio/dac/spidac.yaml > new file mode 100644 > index 000000000000..be98da728594 > --- /dev/null > +++ b/Documentation/devicetree/bindings/iio/dac/spidac.yaml > @@ -0,0 +1,69 @@ > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/iio/dac/spidac.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Generic "shift register" SPI DAC > + > +description: > + Supports simple SPI "shift register" DACs, like TI's DAC714. These DACs have > + no control registers or commands, they just use a clock and serial data to > + shift in a raw DAC value. Multiple DACs can be daisy-chained together. > + > +maintainers: > + - Mike Looijmans <mike.looijmans@xxxxxxxx> > + > +properties: > + compatible: > + enum: > + - spi-dac > + - ti,dac714 Why does TI chip need a specific compatible and others don't? Are power supplies on these chips the same? > + > + reg: > + maxItems: 1 > + > + ldac-gpios: > + description: > + LDAC pin to be used as a hardware trigger to update the DAC outputs. Not > + needed when the DACs use the chip select to update their output. > + maxItems: 1 > + > + reset-gpios: > + description: > + Optional reset pin that resets all DACs. > + maxItems: 1 > + > + num-channels: > + description: > + Number of channels (usually the number of DAC chips in series) usually? What other possible option is there? If something else, how is the driver going to distinguish that? default: 1 > + $ref: /schemas/types.yaml#/definitions/uint32 > + > + bits-per-channel: Perhaps 'channel-bits' as -bits is a standard unit suffix. > + description: > + Number of bits for each DAC output. > + $ref: /schemas/types.yaml#/definitions/uint32 Constraints? I assume all DACs are much less than 2^32 bits. default? > + > +required: > + - compatible > + - reg Don't you always need to know how many bits? > + > +allOf: > + - $ref: /schemas/spi/spi-peripheral-props.yaml# > + > +unevaluatedProperties: false > + > +examples: > + - | > + #include <dt-bindings/gpio/gpio.h> > + spi { > + #address-cells = <1>; > + #size-cells = <0>; > + > + dac@1 { > + compatible = "spidac"; > + reg = <0x1>; > + ldac-gpios = <&gpio 42 GPIO_ACTIVE_LOW>; > + }; > + }; > +... > -- > 2.34.1 > > > Met vriendelijke groet / kind regards, > > Mike Looijmans > System Expert > > > TOPIC Embedded Products B.V. > Materiaalweg 4, 5681 RJ Best > The Netherlands > > T: +31 (0) 499 33 69 69 > E: mike.looijmans@xxxxxxxx > W: www.topic.nl > > Please consider the environment before printing this e-mail
