Re: [PATCH v6 1/2] dt-bindings: leds: backlight: Add Kinetic KTZ8866 backlight
From: Jianhua Lu
Date: Wed Jan 18 2023 - 09:19:42 EST
On Wed, Jan 18, 2023 at 02:40:00PM +0100, Krzysztof Kozlowski wrote:
> On 18/01/2023 14:10, Jianhua Lu wrote:
> > Add Kinetic KTZ8866 backlight binding documentation.
> >
> > Signed-off-by: Jianhua Lu <lujianhua000@xxxxxxxxx>
> > ---
> > Changes in v2:
> > - Remove "items" between "compatible" and "const: kinetic,ktz8866"
> > - Change "additionalProperties" to "unevaluatedProperties"
> >
> > Changes in v3:
> > - Add Krzysztof's R-b
> >
> > Changes in v4:
> > - Drop Krzysztof's R-b
> > - Add some new properties
> >
> > Changes in v5:
> > - Add missing enum under property description.
> > - Rename uncorrect properties.
> >
> > Changes in v6:
> > - Correct wrong property suffix and description.
> >
> > .../leds/backlight/kinetic,ktz8866.yaml | 59 +++++++++++++++++++
> > 1 file changed, 59 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml b/Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml
> > new file mode 100644
> > index 000000000000..ca0deba14523
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml
> > @@ -0,0 +1,59 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/leds/backlight/kinetic,ktz8866.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Kinetic Technologies KTZ8866 backlight
> > +
> > +maintainers:
> > + - Jianhua Lu <lujianhua000@xxxxxxxxx>
> > +
> > +description: |
> > + The Kinetic Technologies KTZ8866 is a high efficiency 6-sinks led backlight
> > + with dual lcd bias power.
> > + https://www.kinet-ic.com/ktz8866/
> > +
> > +allOf:
> > + - $ref: common.yaml#
> > +
> > +properties:
> > + compatible:
> > + const: kinetic,ktz8866
> > +
> > + current-num-sinks:
> > + description: Number of LED current sinks.
> > + enum: [1, 2, 3, 4, 5, 6]
> > +
> > + current-ramping-time-ms:
> > + description: LED current ramping time in milliseconds.
> > + enum: [2, 4, 8, 16, 32, 64, 128, 192, 256, 320, 384, 448, 512, 576, 640]
> > +
> > + led-ramping-time-ms:
> > + description: |
> > + LED on/off ramping time in milliseconds, note that the case 0 will be mapped
> > + to 512μs because ktz8866 can't ramp faster than it.
>
> Aren't you just missing supplies here and their ramp up time?
>
backlight ic supply bias power to panel, but downsteam devicetree adds power supplies node to panel node,
so I'm not sure if need to add power supplies to backlight node.
> > + enum: [0, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384]
> > +
> > + enable-lcd-bias:
> > + description: Set if we want to output bias power supply for LCD.
>
> Is it a generic property? I don't see any other users, so this looks
> device specific thus needs vendor prefix.
>
> This applies to all of the properties. They might be generic or might
> not, I don't know the backlight hardware that much.
It surely is device specific, thanks.
>
> > + type: boolean
> > +
> > +required:
> > + - compatible
> > +
> > +unevaluatedProperties: false
> > +
> > +examples:
> > + - |
> > + backlight {
> > + compatible = "kinetic,ktz8866";
> > +
> > + pinctrl-names = "default";
> > + pinctrl-0 = <&bl_en_default>;
> > +
> > + current-num-sinks = <5>;
> > + current-ramping-time-ms = <128>;
> > + led-ramping-time-ms = <1>;
> > + enable-lcd-bias;
> > + };
>
> Best regards,
> Krzysztof
>