Hi Conor, ... > On Fri, Oct 20, 2023 at 03:54:33PM +0200, Flavio Suligoi wrote: > > The two properties: > > > > - max-brightness > > - default brightness > > > > are not really required, so they can be removed from the "required" > > section. > > Why are they not required? You need to provide an explanation. The "max-brightness" is not more used now in the driver (I used it in the first version of the driver). The "default-brightness", if omitted in the DT, is managed by the device driver, using a default value. This 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; if it is omitted, the driver uses a default array of 0..255 and the "default-brightness" is the last one, which is "255". > > 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 > > Why is this more useful? I introduced the "brightness-levels" instead of "max-brightness" for homogeneity, since the "analog mode" dimming has a brightness-levels array fixed by hardware (0..31). In this way also the "pwm" mode can use the same concepts of array of levels. > > Cheers, > Conor. Thanks for your help. Flavio. > > > > > 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 > >
