Re: [PATCH 3/3] dt-bindings: iio: Add ltc2688 documentation

Rob Herring
2021-12-15T21:30:40Z

On Tue, Dec 14, 2021 at 05:56:08PM +0100, Nuno Sá wrote:
> Document the LTC2688 devicetree properties.
>
> Signed-off-by: Nuno Sá <nuno.sa@analog.com>
> ---
> .../bindings/iio/dac/adi,ltc2688.yaml | 146 ++++++++++++++++++
> MAINTAINERS | 1 +
> 2 files changed, 147 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..7919cd8ec7c9
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/dac/adi,ltc2688.yaml
> @@ -0,0 +1,146 @@
> +# 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.
> +
> + reset-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
> +
> + clocks:
> + minItems: 1
> + maxItems: 3
> +
> + clock-names:
> + minItems: 1
> + maxItems: 3
> + items:
> + enum: [TGP1, TGP2, TGP3]

pattern: '^TGP[1-3]$'

> +
> + '#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-millivolt:

Not one of the defined units. Use '-microvolt'
> + description:
> + Specify the channel output full scale range. Allowed values are
> + <0 5000>
> + <0 10000>
> + <-5000 5000>
> + <-10000 10000>
> + <-15000 15000>

Looks like constraints.

items:
- enum: [ -15000, -10000, -5000, 0 ]
- enum: [ 5000, 10000, 15000 ]

though that will need to all be x1000.

> + $ref: /schemas/types.yaml#/definitions/int32-array

And drop the type.

> +
> + adi,overrange:
> + description: Enable 5% overrange over the selected full scale range.
> + type: boolean
> +
> + 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]
> +
> + 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>;
> +
> + clocks = <&clock_tgp2>;
> + clock-names = "TGP2";
> +
> + #address-cells = <1>;
> + #size-cells = <0>;
> + channel@0 {
> + reg = <0>;
> + adi,toggle-mode;
> + adi,overrange;
> + };
> +
> + channel@1 {
> + reg = <1>;
> + adi,output-range-millivolt = <(-10000) 10000>;
> + adi,toggle-dither-input = <2>;
> + };
> + };
> + };
> +
> +...
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 61b1eaad4611..4ee2a1b6bf62 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -11168,6 +11168,7 @@ 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
> --
> 2.17.1
>
>