Re: [PATCH 2/3] dt-bindings: input: Add bindings for Immersion ISA1200

[Rob Herring <robh@kernel.org>]

On Wed, Mar 16, 2022 at 12:35:27AM +0100, Linus Walleij wrote:
> This adds device tree bindings for the Immersion ISA1200
> haptic feedback unit.
> 
> Cc: phone-devel@vger.kernel.org
> Cc: devicetree@vger.kernel.org
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
>  .../bindings/input/immersion,isa1200.yaml     | 74 +++++++++++++++++++
>  1 file changed, 74 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/input/immersion,isa1200.yaml
> 
> diff --git a/Documentation/devicetree/bindings/input/immersion,isa1200.yaml b/Documentation/devicetree/bindings/input/immersion,isa1200.yaml
> new file mode 100644
> index 000000000000..e6bbefce74a8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/immersion,isa1200.yaml
> @@ -0,0 +1,74 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/input/immersion,isa1200.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Immersion ISA1200 Haptic Feedback Unit
> +
> +maintainers:
> +  - Linus Walleij <linus.walleij@linaro.org>
> +
> +description:
> +  The Immersion ISA1200 is a haptic feedback chip using two motors of
> +  LRA or ERM type. It can generate a PWM signal to control the motors from
> +  a fixed input clock, or it can amplify and modify an existing PWM
> +  input. It is communicating with the host system using I2C.
> +
> +properties:
> +  compatible:
> +    description: One compatible per product using this chip. Each product
> +      need deliberate custom values for things such as LRA resonance
> +      frequency and these are not stored in the device tree, rather we
> +      let the operating system look up the appropriate parameters from a
> +      table.
> +    enum:
> +      - immersion,isa1200-janice
> +      - immersion,isa1200-gavini

Same device, different boards. I think I would put necessary properties 
in the DT.

> +
> +  reg:
> +    description: I2C address for the ISA1200
> +
> +  hen-gpios:
> +    description: GPIO line that drives the HEN (Motor Hardware Enable) pin
> +      on the chip.
> +    maxItems: 1
> +
> +  len-gpios:
> +    description: GPIO line that drives the LEN (LDO Enable) pin on the chip.
> +    maxItems: 1
> +
> +  clocks:
> +    description: Clock that drives the chip if using the chip to generate a
> +      PWM from a clock. Either clocks or pwms must be defined.
> +    maxItems: 1
> +
> +  pwms:
> +    description: PWM that drives the chip if using an external PWM generator.
> +      Either pwms or clocks must be defined.

That can be expressed as:

oneOf:
 - required: [ clocks ]
 - required: [ pwms ]

(or 'anyOf' if you want to allow both)

> +    maxItems: 1
> +
> +required:
> +  - compatible
> +  - reg
> +  - hen-gpios
> +  - len-gpios
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/gpio/gpio.h>
> +
> +    i2c {
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +
> +      haptic@49 {
> +        compatible = "immersion,isa1200-janice";
> +        reg = <0x49>;
> +        hen-gpios = <&gpio6 2 GPIO_ACTIVE_HIGH>;
> +        len-gpios = <&gpio6 3 GPIO_ACTIVE_HIGH>;
> +        clocks = <&clkout_clk>;
> +      };
> +    };
> -- 
> 2.35.1
> 
>