Re: [PATCH V4 1/4] backlight: qcom-wled: convert the wled bindings to .yaml format

[Rob Herring]

On Mon, Mar 23, 2020 at 11:16:55PM +0530, Kiran Gunda wrote:
> Convert the qcom-wled bindings from .txt to .yaml format.
> 
> Signed-off-by: Kiran Gunda <kgunda@xxxxxxxxxxxxxx>
> Signed-off-by: Subbaraman Narayanamurthy <subbaram@xxxxxxxxxxxxxx>
> Acked-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
> ---
>  .../bindings/leds/backlight/qcom-wled.txt          | 154 -----------------
>  .../bindings/leds/backlight/qcom-wled.yaml         | 184 +++++++++++++++++++++
>  2 files changed, 184 insertions(+), 154 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
>  create mode 100644 Documentation/devicetree/bindings/leds/backlight/qcom-wled.yaml

> diff --git a/Documentation/devicetree/bindings/leds/backlight/qcom-wled.yaml b/Documentation/devicetree/bindings/leds/backlight/qcom-wled.yaml
> new file mode 100644
> index 0000000..8a388bf
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/backlight/qcom-wled.yaml
> @@ -0,0 +1,184 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/backlight/qcom-wled.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Binding for Qualcomm Technologies, Inc. WLED driver
> +
> +maintainers:
> +  - Lee Jones <lee.jones@xxxxxxxxxx>

Should be the h/w owner (you), not who applies patches.

> +
> +description: |
> +  WLED (White Light Emitting Diode) driver is used for controlling display
> +  backlight that is part of PMIC on Qualcomm Technologies, Inc. reference
> +  platforms. The PMIC is connected to the host processor via SPMI bus.
> +
> +properties:
> +  compatible :

Drop the space ^

> +    enum:
> +       - qcom,pm8941-wled
> +       - qcom,pmi8998-wled
> +       - qcom,pm660l-wled

Wrong indent (1 space too many).

> +
> +  reg:
> +    maxItems: 1
> +
> +  default-brightness:
> +    maxItems: 1

maxItems is for arrays and this is a single scalar.

> +    description:
> +      brightness value on boot, value from 0-4095.

0-4095 sounds like a constraint.

> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32

There should be a common definition for this.

> +        default: 2048
> +
> +  label:
> +    maxItems: 1
> +    description:
> +      The name of the backlight device.
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/string

Already has a type. Just 'label: true' is enough.

> +
> +  qcom,cs-out:
> +    description:
> +      enable current sink output.
> +      This property is supported only for PM8941.
> +    type: boolean
> +
> +  qcom,cabc:
> +    description:
> +      enable content adaptive backlight control.
> +    type: boolean
> +
> +  qcom,ext-gen:
> +    description:
> +      use externally generated modulator signal to dim.
> +      This property is supported only for PM8941.
> +    type: boolean
> +
> +  qcom,current-limit:
> +    maxItems: 1

Not an array.

> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +    description:
> +      mA; per-string current limit; value from 0 to 25 with

25 sounds like a constraint.

> +      1 mA step. This property is supported only for pm8941.
> +    default: 20
> +
> +  qcom,current-limit-microamp:
> +    maxItems: 1
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32

properties with unit suffix already have a type.

> +    description:
> +      uA; per-string current limit; value from 0 to 30000 with
> +      2500 uA step.

steps can be expressed using 'multipleOf'

> +    default: 25

25 can never be a multiple of 2500

> +
> +  qcom,current-boost-limit:
> +    maxItems: 1
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +    description:
> +      mA; boost current limit.
> +      For pm8941 one of 105, 385, 525, 805, 980, 1260, 1400, 1680.
> +      Default, 805 mA.
> +      For pmi8998 one of 105, 280, 450, 620, 970, 1150, 1300,
> +      1500. Default 970 mA.

Constraints.

> +
> +  qcom,switching-freq:
> +    maxItems: 1
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +    description:
> +      kHz; switching frequency; one of 600, 640, 685, 738,
> +      800, 872, 960, 1066, 1200, 1371, 1600, 1920, 2400, 3200,
> +      4800, 9600.
> +      Default for pm8941 1600 kHz
> +               for pmi8998 800 kHz

Constraints!

> +
> +  qcom,ovp:
> +    maxItems: 1
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +    description:
> +      V; Over-voltage protection limit; one of 27, 29, 32, 35. Default 29V
> +      This property is supported only for PM8941.
> +
> +  qcom,ovp-millivolt:
> +    maxItems: 1
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +    description:
> +      mV; Over-voltage protection limit;
> +      For pmi8998 one of 18100, 19600, 29600, 31100.
> +      Default 29600 mV.
> +      If this property is not specified for PM8941, it
> +      falls back to "qcom,ovp" property.
> +
> +  qcom,num-strings:
> +    maxItems: 1
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +    description:
> +      number of led strings attached;
> +      value for PM8941 from 1 to 3. Default 2
> +      For PMI8998 from 1 to 4.
> +
> +  interrupts:
> +    maxItems: 2

items:
  - description: ...
  - description: ...

> +    description:
> +      Interrupts associated with WLED. This should be
> +      "short" and "ovp" interrupts. Interrupts can be
> +      specified as per the encoding listed under
> +      Documentation/devicetree/bindings/spmi/
> +      qcom,spmi-pmic-arb.txt.

encoding is outside the scope of the binding.

> +
> +  interrupt-names:
> +    description:
> +      Interrupt names associated with the interrupts.
> +      Must be "short" and "ovp". The short circuit detection
> +      is not supported for PM8941.

Names should be constraints.

> +
> +  qcom,enabled-strings:
> +    maxItems: 1
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32-array
> +    description:
> +      Array of the WLED strings numbered from 0 to 3. Each
> +      string of leds are operated individually. Specify the
> +      list of strings used by the device. Any combination of
> +      led strings can be used.
> +
> +  qcom,external-pfet:
> +    description:
> +      Specify if external PFET control for short circuit
> +      protection is used. This property is supported only
> +      for PMI8998.
> +    type: boolean
> +
> +  qcom,auto-string-detection:
> +    description:
> +      Enables auto-detection of the WLED string configuration.
> +      This feature is not supported for PM8941.
> +    type: boolean
> +
> +required:
> +  - compatible
> +  - reg
> +  - label
> +
> +examples:
> +  - |
> +    pm8941-wled@d800 {

backlight@...

> +        compatible = "qcom,pm8941-wled";
> +        reg = <0xd800 0x100>;
> +        label = "backlight";
> +
> +        qcom,cs-out;
> +        qcom,current-limit = <20>;
> +        qcom,current-boost-limit = <805>;
> +        qcom,switching-freq = <1600>;
> +        qcom,ovp = <29>;
> +        qcom,num-strings = <2>;
> +        qcom,enabled-strings = <0 1>;
> +     };
> -- 
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>