Re: [PATCH v3 3/3] dt-bindings: iio: adc: Add docs for ad7124

From: Rob Herring
Date: Tue Oct 30 2018 - 16:56:29 EST


On Mon, Oct 29, 2018 at 06:39:30PM +0200, Stefan Popa wrote:
> Add support for Analog Devices AD7124 4-channels and 8-channels ADC.
>
> Signed-off-by: Stefan Popa <stefan.popa@xxxxxxxxxx>
> ---
> Changes in v2:
> - Nothing changed.
> Changes in v3:
> - Removed the "adi,channels" property.
> - Used the "reg" property to get the channel number and "adi,diff-channels"
> for the differential pins. The "adi,channel-number" property was removed.
> - adi,bipolar is of boolean type.
>
> .../devicetree/bindings/iio/adc/adi,ad7124.txt | 90 ++++++++++++++++++++++
> MAINTAINERS | 1 +
> 2 files changed, 91 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,ad7124.txt
>
> diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7124.txt b/Documentation/devicetree/bindings/iio/adc/adi,ad7124.txt
> new file mode 100644
> index 0000000..46a9b71
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7124.txt
> @@ -0,0 +1,90 @@
> +Analog Devices AD7124 ADC device driver
> +
> +Required properties for the AD7124:
> + - compatible: Must be one of "adi,ad7124-4" or "adi,ad7124-8"
> + - reg: SPI chip select number for the device
> + - spi-max-frequency: Max SPI frequency to use
> + see: Documentation/devicetree/bindings/spi/spi-bus.txt
> + - clocks: phandle to the master clock (mclk)
> + see: Documentation/devicetree/bindings/clock/clock-bindings.txt
> + - clock-names: Must be "mclk".
> + - interrupts: IRQ line for the ADC
> + see: Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
> +
> + Required properties:
> + * #address-cells: Must be 1.
> + * #size-cells: Must be 0.
> +
> + Subnode(s) represent the external channels which are connected to the ADC.
> + Each subnode represents one channel and has the following properties:
> + Required properties:
> + * reg: The channel number. It can have up to 4 channels on ad7124-4
> + and 8 channels on ad7124-8, numbered from 0 to 15.
> + * adi,diff-channels: Pins the channel is connected to. The first value
> + specifies the positive input pin, the second value the negative input pin.
> +
> + Optional properties:
> + * adi,bipolar: Boolean, if set the channel is used in bipolar mode.

Both this and Xilinx AMS which I just reviewed are defining a bipolar
property. Can we come up with a common property please.

> + * adi,reference-select: Select the reference source to use when
> + converting on the the specific channel. Valid values are:
> + 0: REFIN1(+)/REFIN1(â).
> + 1: REFIN2(+)/REFIN2(â).
> + 3: AVDD
> + If this field is left empty, internal reference is selected.
> + * adi,gain: Select the gain when converting on the specific channel.
> + Valid values are: 1, 2, 4, 8, 16, 32, 64, 128.
> + If this field is left empty, gain of 1 is selected.
> + * adi,odr-hz: The output data rate can be programmed from:
> + 9 to 19200 for full power mode (when the master clock is 614.4 kHz)
> + 2 to 4800 for mid power mode (when the master clock is 153.6 kHz)
> + 1 to 2400 for low power mode (when the master clock is 76.8 kHz)
> + If this field is left empty, odr of 9 is selected.
> +
> +Optional properties:
> + - refin1-supply: refin1 supply can be used as reference for conversion.
> + - refin2-supply: refin2 supply can be used as reference for conversion.
> + - avdd-supply: avdd supply can be used as reference for conversion.
> +
> +Example:
> + adc@0 {
> + compatible = "adi,ad7124-4";
> + reg = <0>;
> + spi-max-frequency = <5000000>;
> + interrupts = <25 2>;
> + interrupt-parent = <&gpio>;
> + refin1-supply = <&adc_vref>;
> + clocks = <&ad7124_mclk>;
> + clock-names = "mclk";
> +
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + channel@0 {
> + reg = <0>;
> + adi,diff-channels = <0 1>;
> + adi,reference-select = <0>;
> + adi,gain = <2>;
> + adi,odr-hz = <10>;
> + };
> +
> + channel@1 {
> + reg = <1>;
> + adi,bipolar;
> + adi,diff-channels = <2 3>;
> + adi,reference-select = <0>;
> + adi,gain = <4>;
> + adi,odr-hz = <50>;
> + };
> +
> + channel@2 {
> + reg = <2>;
> + adi,diff-channels = <4 5>;
> + adi,gain = <128>;
> + adi,odr-hz = <19200>;
> + };
> +
> + channel@3 {
> + reg = <3>;
> + adi,diff-channels = <6 7>;
> + };
> + };
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 3a1bfcb..f2fa508 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -845,6 +845,7 @@ L: linux-iio@xxxxxxxxxxxxxxx
> W: http://ez.analog.com/community/linux-device-drivers
> S: Supported
> F: drivers/iio/adc/ad7124.c
> +F: Documentation/devicetree/bindings/iio/adc/adi,ad7124.txt
>
> ANALOG DEVICES INC AD9389B DRIVER
> M: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> --
> 2.7.4
>