Re: [PATCH v1 3/3] dt-bindings: iio: afe: Add hwmon example

From: Peter Rosin
Date: Tue Jun 11 2019 - 07:18:45 EST


On 2019-06-11 11:56, MylÃne Josserand wrote:
> With the support of CHAN_INFO_PROCESSED in voltage-divider,
> it is possible to read the processed values directly from iio's
> sysfs entries or by using iio-hwmon. Add an example for this last
> use case.

As I wrote in response to the cover letter, I think iio-hwmon
could "consume" voltage dividers just fine before adding the
processed channel, and while more examples might be good,
there is really no specific relation between iio-hwmon and
voltage dividers. Adding iio-hwmon examples to each and every
iio binding seems pointless. So, I see little reason to add
such examples here.

But if everyone else wants it, don't let me stand in the way...

Cheers,
Peter

> Signed-off-by: MylÃne Josserand <mylene.josserand@xxxxxxxxxxx>
> ---
> .../bindings/iio/afe/voltage-divider.txt | 24 ++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/iio/afe/voltage-divider.txt b/Documentation/devicetree/bindings/iio/afe/voltage-divider.txt
> index b452a8406107..f7e1c7cb2744 100644
> --- a/Documentation/devicetree/bindings/iio/afe/voltage-divider.txt
> +++ b/Documentation/devicetree/bindings/iio/afe/voltage-divider.txt
> @@ -51,3 +51,27 @@ sysv {
> spi-max-frequency = <1000000>;
> };
> };
> +
> +It is also possible to retrieve the processed values using hwmon node:
> +
> +div0: div0 {
> + compatible = "voltage-divider";
> + io-channels = <&adc0 0>; /* Channel 0 of the ADC */
> + output-ohms = <47>; /* R2 */
> + full-ohms = <73>; /* R1 (26) + R2 (47) */
> + #io-channel-cells = <1>;
> +};
> +
> +div1: div1 {
> + compatible = "voltage-divider";
> + io-channels = <&adc0 1>; /* Channel 1 of the ADC */
> + output-ohms = <47>; /* R2 */
> + full-ohms = <115>; /* R1 (68) + R2 (47) */
> + #io-channel-cells = <1>;
> +};
> +
> +iio-hwmon {
> + compatible = "iio-hwmon";
> + io-channels = <&div0 0>, <&div1 0>;
> + io-channel-names = "3v3", "usb";
> +};
>