Re: [PATCH v3 1/4] dt-bindings: iio: magnetometer: ak8975: convert txt format to yaml

[Stephan Gerhold <stephan@gerhold.net>]

On Tue, May 19, 2020 at 02:43:51PM +0200, Jonathan Albrieux wrote:
> Converts documentation from txt format to yaml.
> 
> Signed-off-by: Jonathan Albrieux <jonathan.albrieux@gmail.com>
> ---
>  .../bindings/iio/magnetometer/ak8975.txt      | 30 ---------
>  .../bindings/iio/magnetometer/ak8975.yaml     | 66 +++++++++++++++++++
>  2 files changed, 66 insertions(+), 30 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt
>  create mode 100644 Documentation/devicetree/bindings/iio/magnetometer/ak8975.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt b/Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt
> deleted file mode 100644
> index aa67ceb0d4e0..000000000000
> --- a/Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt
> +++ /dev/null
> @@ -1,30 +0,0 @@
> -* AsahiKASEI AK8975 magnetometer sensor
> -
> -Required properties:
> -
> -  - compatible : should be "asahi-kasei,ak8975"
> -  - reg : the I2C address of the magnetometer
> -
> -Optional properties:
> -
> -  - gpios : should be device tree identifier of the magnetometer DRDY pin
> -  - vdd-supply: an optional regulator that needs to be on to provide VDD
> -  - mount-matrix: an optional 3x3 mounting rotation matrix
> -
> -Example:
> -
> -ak8975@c {
> -        compatible = "asahi-kasei,ak8975";
> -        reg = <0x0c>;
> -        gpios = <&gpj0 7 0>;
> -        vdd-supply = <&ldo_3v3_gnss>;
> -        mount-matrix = "-0.984807753012208",  /* x0 */
> -                       "0",                   /* y0 */
> -                       "-0.173648177666930",  /* z0 */
> -                       "0",                   /* x1 */
> -                       "-1",                  /* y1 */
> -                       "0",                   /* z1 */
> -                       "-0.173648177666930",  /* x2 */
> -                       "0",                   /* y2 */
> -                       "0.984807753012208";   /* z2 */
> -};
> diff --git a/Documentation/devicetree/bindings/iio/magnetometer/ak8975.yaml b/Documentation/devicetree/bindings/iio/magnetometer/ak8975.yaml
> new file mode 100644
> index 000000000000..86e3efa693a8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/magnetometer/ak8975.yaml
> @@ -0,0 +1,66 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/magnetometer/ak8975.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: AsahiKASEI AK8975 magnetometer sensor
> +
> +maintainers:
> +  - can't find a mantainer, author is Laxman Dewangan <ldewangan@nvidia.com>

Should probably add someone here, although I'm not sure who either.

> +
> +properties:
> +  compatible:
> +    enum:
> +      - "asahi-kasei,ak8975"
> +      - "ak8975"
> +      - "asahi-kasei,ak8963"
> +      - "ak8963"
> +      - "asahi-kasei,ak09911"
> +      - "ak09911"
> +      - "asahi-kasei,ak09912"
> +      - "ak09912"
> +

I wonder if the ones without vendor prefix (asahi-kasei,) should be
marked as deprecated somehow?

Looking at some other schemas I see either a "# deprecated" comment, or:

properties:
  compatible:
    oneOf:
      - const: asahi-kasei,ak8975
      - const: asahi-kasei,ak8963
      - const: asahi-kasei,ak09911
      - const: asahi-kasei,ak09912
      - const: ak8975
        deprecated: true
      - const: ak8963
        deprecated: true
      - const: ak09911
        deprecated: true
      - const: ak09912
        deprecated: true

(e.g. in Documentation/devicetree/bindings/sound/samsung,odroid.yaml)
I guess this one is preferred since it allows parsing those
compatibles as deprecated?

> +  reg:
> +    maxItems: 1
> +    description: the I2C address of the magnetometer
> +
> +  gpios:
> +    description: should be device tree identifier of the magnetometer DRDY pin
> +
> +  vdd-supply:
> +    maxItems: 1
> +    description: |
> +      an optional regulator that needs to be on to provide VDD power to
> +      the sensor.
> +
> +  mount-matrix:
> +    description: an optional 3x3 mounting rotation matrix
> +
> +required:
> +  - compatible
> +  - reg
> +
> +examples:
> +  - |
> +    i2c@78b7000 {
> +        reg = <0x78b6000 0x600>;
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        ak8975@c {

Per device tree specification this should preferably use a generic name
describing the function of the device, i.e. magnetometer@c.

> +            compatible = "asahi-kasei,ak8975";
> +            reg = <0x0c>;
> +            gpios = <&gpj0 7 0>;

I think using the dt-bindings constants for the GPIO flags is preferred
now, i.e. gpios = <&gpj0 7 GPIO_ACTIVE_HIGH>.

> +            vdd-supply = <&ldo_3v3_gnss>;
> +            mount-matrix = "-0.984807753012208",  /* x0 */
> +                           "0",                   /* y0 */
> +                           "-0.173648177666930",  /* z0 */
> +                           "0",                   /* x1 */
> +                           "-1",                  /* y1 */
> +                           "0",                   /* z1 */
> +                           "-0.173648177666930",  /* x2 */
> +                           "0",                   /* y2 */
> +                           "0.984807753012208";   /* z2 */
> +        };
> +    };
> -- 
> 2.17.1