On Fri, May 26, 2023 at 1:20 PM Daniel Thompson <daniel.thompson@xxxxxxxxxx> wrote: > > On Fri, May 19, 2023 at 11:05:20PM +0300, Alexandru Ardelean wrote: > > From: Yannick Fertre <yannick.fertre@xxxxxxxxxxx> > > > > Add documentation for new default-brightness-level property. > > > > Reviewed-by: Philippe CORNU <philippe.cornu@xxxxxxxxxxx> > > Signed-off-by: Yannick Fertre <yannick.fertre@xxxxxxxxxxx> > > Signed-off-by: Alexandru Ardelean <alex@xxxxxxxxxxx> > > --- > > > > Link to original patch: > > https://github.com/STMicroelectronics/linux/commit/c4067d7bd883c6fa14ffd49892c4ce663cdafe98 > > > > .../bindings/leds/backlight/gpio-backlight.yaml | 9 +++++++++ > > 1 file changed, 9 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.yaml b/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.yaml > > index 584030b6b0b9..b96c08cff0f0 100644 > > --- a/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.yaml > > +++ b/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.yaml > > @@ -23,6 +23,15 @@ properties: > > description: enable the backlight at boot. > > type: boolean > > > > + default-brightness-level: > > + description: > > + The default brightness level (index into the array defined by the > > + "brightness-levels" property). > > gpio-backlight does not have a brightness-levels array property! > > I think it is also necessary to improve the docs of both properties to > distinguish between the meaning of default-on and > default-brightness-level. The result of setting default-on and > default-brightness level to zero is that the GPIO will be off (this is > correct behaviour but hard to figure out from the current text). > > default-on is a control that can "enable" the backlight at boot when it > is not linked to a display in the DT (e.g. it is mostly for legacy > cases). When the backlight is linked to a display then the backlight > enable state will be automatically linked to the display enable state > instead. > > default-brightness-level is useful for handling displays that > are still readable with the backlight off (e-ink, reflective/ > transflexive LCD, etc), otherwise is should be absent or set to 1. ack will do in V2 thanks > > > > + $ref: /schemas/types.yaml#/definitions/uint32 > > + > > +dependencies: > > + default-brightness-level: [ "brightness-levels" ] > > As above, depending on brightness-levels doesn't make any sense here. > > > Daniel.
