Re: [PATCH 2/2] staging: iio: ad2s1210: Add devicetree yaml doc

[Jonathan Cameron <jic23@kernel.org>]

On Sat, 18 May 2019 19:15:58 -0300
Tallys Martins <tallysmartins@gmail.com> wrote:

> The driver currently has no devicetree documentation. This commit adds a
> devicetree folder and documentation for it. Documentation must be moved
> as well when the driver gets out of staging.
> 
> Signed-off-by: Tallys Martins <tallysmartins@gmail.com>
> Signed-off-by: Souza Guilherme <gdsdsilva@inf.ufpel.edu.br>
> Co-developed-by: Souza Guilherme <gdsdsilva@inf.ufpel.edu.br>

Hi,

There is no need for a direct relationship between a binding and a driver
at all. As such, we normally don't take binding documents in staging.

Just put it directly in it's final destination.  The driver can catch
up with it later!

I'm still not that comfortable with yaml (haven't gotten around
to doing any conversions myself yet) so I'll be looking for additional
review on these from others.

A few comments inline.

> ---
>  .../Documentation/devicetree/ad2s1210.yaml    | 41 +++++++++++++++++++
>  1 file changed, 41 insertions(+)
>  create mode 100644 drivers/staging/iio/Documentation/devicetree/ad2s1210.yaml
> 
> diff --git a/drivers/staging/iio/Documentation/devicetree/ad2s1210.yaml b/drivers/staging/iio/Documentation/devicetree/ad2s1210.yaml
> new file mode 100644
> index 000000000000..733aa07b4626
> --- /dev/null
> +++ b/drivers/staging/iio/Documentation/devicetree/ad2s1210.yaml
> @@ -0,0 +1,41 @@
> +# SPDX-License-Identifier: GPL-2.0
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/iio/ad2s1210.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: |
> +  Analog Devices Inc. AD2S1210 10-Bit to 16-Bit R/D Converters
> +
> +maintainers:
> +  - Graff Yang <graff.yang@gmail.com>
I would check that one with the Analog devices team.

> +
> +description: |
> +  Analog Devices AD2S1210 Resolver to Digital SPI driver
> +
> +  https://www.analog.com/en/products/ad2s1210.html
> +
> +properties:
> +  compatible:
> +    enum:
> +      - adi,ad2s1210
> +
> +  reg:
> +    maxItems: 1
> +
> +  clock-frequency:
> +    minimum: 2000
> +    maximum: 20000
> +    default: 8192
This doesn't look like a modern clock binding.
If we are going to end up changing this, then we should probably delay
having a binding doc until after that change is made.

We often only do binding docs for drivers in staging just before moving
them out so as to avoid this sort of issue.
 
> +
> +required:
> +  - compatible
> +  - reg
> +
> +examples:
> +  - |
> +  resolver@0 {
> +    compatible = "adi,ad2s1210";
> +    reg = <0>;
An example is probably more useful if it includes all the optional properties
as well.
> +  };
> +...

Thanks,

Jonathan