On Thu, Jul 16, 2020 at 4:00 PM Maxime Ripard <maxime@xxxxxxxxxx> wrote: > > On Tue, Jul 14, 2020 at 03:13:01PM +0800, Chen-Yu Tsai wrote: > > From: Chen-Yu Tsai <wens@xxxxxxxx> > > > > Some LCD panels do not support 24-bit true color, or 8bits per channel > > RGB. Many low end ones only support up to 6 bits per channel natively. > > > > Add a device tree property to describe the native bit depth of the > > panel. This is separate from the bus width or format of the connection > > to the display output. > > > > Signed-off-by: Chen-Yu Tsai <wens@xxxxxxxx> > > --- > > .../devicetree/bindings/display/panel/panel-dpi.yaml | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/display/panel/panel-dpi.yaml b/Documentation/devicetree/bindings/display/panel/panel-dpi.yaml > > index 0cd74c8dab42..8eb013fb1969 100644 > > --- a/Documentation/devicetree/bindings/display/panel/panel-dpi.yaml > > +++ b/Documentation/devicetree/bindings/display/panel/panel-dpi.yaml > > @@ -26,6 +26,9 @@ properties: > > height-mm: true > > label: true > > panel-timing: true > > + bits-per-color: > > + description: > > + Shall contain an integer describing the number of bits per color. > > You should specify its type (u32), range (1-8 I guess?) and default > value (which seems to be 8). Ok. > Also, it's not unusual to have a different number of bits per color, > like for 16 bits panels where we usually use RGB565. I guess we could > make that an array? So for different number of bits per color, I'm not sure whether that's a function of the panel itself, or the bus format. I don't really have any 16-bit panels on hand. As it stands DRM only handles a common color depth. ChenYu
