> -----Original Message----- > From: Jonathan Cameron <jic23@xxxxxxxxxx> > Sent: Sunday, January 16, 2022 1:02 PM > To: Sa, Nuno <Nuno.Sa@xxxxxxxxxx> > Cc: linux-iio@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; Rob > Herring <robh+dt@xxxxxxxxxx>; Lars-Peter Clausen > <lars@xxxxxxxxxx>; Hennerich, Michael > <Michael.Hennerich@xxxxxxxxxx> > 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@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 > > +--- > > +$id: > https://urldefense.com/v3/__http://devicetree.org/schemas/iio/dac/ > adi,ltc2688.yaml*__;Iw!!A3Ni8CS0y2Y!qhcjFFDY939hv3Lo2iT1fAIbSObt > YscKoXjAnLgWZRNG6_WE2WXgZ8AdE4FUwg$ > > +$schema: > https://urldefense.com/v3/__http://devicetree.org/meta- > schemas/core.yaml*__;Iw!!A3Ni8CS0y2Y!qhcjFFDY939hv3Lo2iT1fAIbS > ObtYscKoXjAnLgWZRNG6_WE2WXgZ8BOzIvN9g$ > > + > > +title: Analog Devices LTC2688 DAC > > + > > +maintainers: > > + - Nuno Sá <nuno.sa@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". 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
