Hi Thierry, On Monday 21 July 2014 14:12:47 Thierry Reding wrote: > On Mon, Jul 21, 2014 at 11:57:37AM +0200, Boris BREZILLON wrote: > > On Mon, 21 Jul 2014 11:32:55 +0200 Laurent Pinchart wrote: > >> On Monday 21 July 2014 11:24:38 Boris BREZILLON wrote: > >>> On Mon, 21 Jul 2014 10:59:12 +0200 Thierry Reding wrote: > >>>> On Fri, Jul 18, 2014 at 05:43:34PM +0200, Boris BREZILLON wrote: > >>>> [...] > >>>> > >>>>>>>>>> + - atmel,panel: Should contain a phandle with 2 parameters. > >>>>>>>>>> + The first cell is a phandle to a DRM panel device > >>>>>>>>>> + The second cell encodes the RGB mode, which can take the > >>>>>>>>>> following values: > >>>>>>>>>> + * 0: RGB444 > >>>>>>>>>> + * 1: RGB565 > >>>>>>>>>> + * 2: RGB666 > >>>>>>>>>> + * 3: RGB888 > >>>>>>>>> > >>>>>>>>> These are properties of the panel and should be obtained from > >>>>>>>>> the panel directly rather than an additional cell in this > >>>>>>>>> specifier. > >>>>>>>> > >>>>>>>> Okay. > >>>>>>>> What's the preferred way of doing this ? > >>>>>>>> What about defining an rgb-mode property in the panel node. > >>>>>>> > >>>>>>> There's .bpc in struct drm_display_info, I suspect that it could > >>>>>>> be used for this. Alternatively, maybe we could extend the list > >>>>>>> of color formats that go into drm_display_info.color_formats? > >>>>>>> RGB444 is already covered. > >>>>> > >>>>> I forgot to ask about bpc meaning. If, as I think, it means "bits > >>>>> per color" then it cannot be used to encode RGB565 where green > >>>>> color is encoded on 6 bits and red and blue are encoded on 5 bits. > >>>> > >>>> Yes, I agree that bps is not a good fit for what you need here. > >>> > >>> Okay, then I think we can replace bpc and color_formats by a > >>> bus_formats table containing all supported formats, and use an enum > >>> (something similar to v4l2_mbus_pixelcode defined in v4l2-mediabus.h > >>> [1]) to list the available formats. > >>> > >>> As this implies quite a few changes in crtc core and some drm drivers > >>> (nouveau, i915 and radeon), I'd like to be sure this is what both of > >>> you had in mind. > >> > >> I think it is, but just to make sure I understand you correctly, could > >> you just show how the drm_display_info structure would look like ? > > > > The new drm_display_info structure should look like this [2] (except > > that color_formats and bpc have not be removed yet), and [1] is just > > here to show how the video_bus_format enum would look like. > > > > [1] http://code.bulix.org/rfd0yx-86557 > > [2] http://code.bulix.org/7n03b4-86556 > > Quoting from your paste: > > + const enum video_bus_format *bus_formats; > + int nbus_formats; > > Do we really need more than one? We do if we want to replace the color_formats and bpc fields. -- Regards, Laurent Pinchart
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