> On Thu, Dec 05, 2013 at 04:43:37PM +0100, Denis Carikli wrote: > > pwmr has to be set to get the imxfb backlight work, > > though pwmr was only configurable trough the platform data. > > > > Cc: Rob Herring <[email protected]> > > Cc: Pawel Moll <[email protected]> > > Cc: Mark Rutland <[email protected]> > > Cc: Stephen Warren <[email protected]> > > Cc: Ian Campbell <[email protected]> > > Cc: [email protected] > > Cc: Jean-Christophe Plagniol-Villard <[email protected]> > > Cc: Tomi Valkeinen <[email protected]> > > Cc: [email protected] > > Cc: Sascha Hauer <[email protected]> > > Cc: [email protected] > > Cc: Eric Bénard <[email protected]> > > Signed-off-by: Denis Carikli <[email protected]> > > Acked-by: Jean-Christophe PLAGNIOL-VILLARD <[email protected]> > > Acked-by: Grant Likely <[email protected]> > > --- > > .../devicetree/bindings/video/fsl,imx-fb.txt | 3 +++ > > drivers/video/imxfb.c | 2 ++ > > 2 files changed, 5 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/video/fsl,imx-fb.txt > > b/Documentation/devicetree/bindings/video/fsl,imx-fb.txt > > index 46da08d..ac457ae 100644 > > --- a/Documentation/devicetree/bindings/video/fsl,imx-fb.txt > > +++ b/Documentation/devicetree/bindings/video/fsl,imx-fb.txt > > @@ -17,6 +17,9 @@ Required nodes: > > Optional properties: > > - fsl,dmacr: DMA Control Register value. This is optional. By default, the > > register is not modified as recommended by the datasheet. > > +- fsl,pwmr: LCDC PWM Contrast Control Register value. That property is > > + optional, but defining it is necessary to get the backlight working. If > > that > > + property is ommited, the register is zeroed. > > Why isn't this implemented as a backlight driver? Static devicetree > provided values is very limiting.
Let's understand the terminology. This register should be renamed according to the datasheet, i.e. LPCCR. As I pointed out earlier, it is NOT control the backlight, this is a contrast control. Yes, it works as PWM, but nothing do with the backlight subsystem. Yes, we can make a driver for this PWM, but how are we going to control it? I misunderstood something? ---
