On Mon, 21 Jul 2014 10:59:12 +0200 Thierry Reding <thierry.reding@xxxxxxxxx> 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. Best Regards, Boris [1]http://lxr.free-electrons.com/source/include/uapi/linux/v4l2-mediabus.h#L37 -- 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
