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

From: Rob Herring
Date: Tue Mar 31 2020 - 13:54:21 EST


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>;
> + };
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>