On Mon, 21 Jul 2014 11:32:55 +0200 Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote: > Hi Boris, > > 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 -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
