On Wed, Oct 25, 2023 at 05:50:57PM +0200, Flavio Suligoi wrote:
> The two properties:
>
> - max-brightness
> - default brightness
>
> are not really required, so they can be removed from the "required"
> section.
> The "max-brightness" is no longer used in the current version
> of the driver (it was used only in the first version).
> The "default-brightness", if omitted in the DT, is managed by the
> device driver, using a default value. This value depends on the dimming
> mode used:
>
> - for the "analog mode", via I2C commands, this value is fixed by
> hardware (=31)
> - while in case of pwm mode the default used is the last value of the
> brightness-levels array.
>
> Also the brightness-levels array is not required:
>
> - in "analog mode", via I2C commands, the brightness-level array is
> fixed by hardware (0..31).;
> - in pwm dimming mode, the driver uses a default array of 0..255 and
> the "default-brightness" is the last one, which is "255"
>
> NOTE: there are no compatibility problems with the previous version,
> since the device driver has not yet been included in any kernel.
> Only this dt-binding yaml file is already included in the
> "for-backlight-next" branch of the "backlight" kernel repository.
> No developer may have used it.
I'd argue
Fixes: 02c4e661658f ("dt-bindings: backlight: Add MPS MP3309C")
but that's up to Lee.
Acked-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
Thanks,
Conor.
>
> Other changes:
>
> - improve the backlight working mode description, in the "description"
> section
> - update the example, removing the "max-brightness" and introducing the
> "brightess-levels" property
>
> Signed-off-by: Flavio Suligoi <f.suligoi@xxxxxxx>
> ---
> .../bindings/leds/backlight/mps,mp3309c.yaml | 10 ++++------
> 1 file changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml b/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
> index 4191e33626f5..527a37368ed7 100644
> --- a/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
> +++ b/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
> @@ -14,8 +14,8 @@ description: |
> programmable switching frequency to optimize efficiency.
> It supports two different dimming modes:
>
> - - analog mode, via I2C commands (default)
> - - PWM controlled mode.
> + - analog mode, via I2C commands, as default mode (32 dimming levels)
> + - PWM controlled mode (optional)
>
> The datasheet is available at:
> https://www.monolithicpower.com/en/mp3309c.html
> @@ -50,8 +50,6 @@ properties:
> required:
> - compatible
> - reg
> - - max-brightness
> - - default-brightness
>
> unevaluatedProperties: false
>
> @@ -66,8 +64,8 @@ examples:
> compatible = "mps,mp3309c";
> reg = <0x17>;
> pwms = <&pwm1 0 3333333 0>; /* 300 Hz --> (1/f) * 1*10^9 */
> - max-brightness = <100>;
> - default-brightness = <80>;
> + brightness-levels = <0 4 8 16 32 64 128 255>;
> + default-brightness = <6>;
> mps,overvoltage-protection-microvolt = <24000000>;
> };
> };
> --
> 2.34.1
>
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