From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [RESEND PATCH v3 06/11] drm: add DT bindings documentation for atmel-hlcdc-dc driver Date: Mon, 21 Jul 2014 14:12:47 +0200 Message-ID: <20140721121245.GA15238@ulmo> References: <1404751384-5077-1-git-send-email-boris.brezillon@free-electrons.com> <20140721085908.GI8843@ulmo> <20140721112438.60452e09@bbrezillon> <1486972.oIqOcvGYCb@avalon> <20140721115737.1377a5fd@bbrezillon> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="YZ5djTAD1cGYuMQK" Return-path: Content-Disposition: inline In-Reply-To: <20140721115737.1377a5fd@bbrezillon> Sender: linux-pwm-owner@vger.kernel.org To: Boris BREZILLON Cc: Laurent Pinchart , Samuel Ortiz , Lee Jones , linux-pwm@vger.kernel.org, David Airlie , dri-devel@lists.freedesktop.org, Nicolas Ferre , Jean-Christophe Plagniol-Villard , Alexandre Belloni , Andrew Victor , Jean-Jacques Hiblot , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , devicetree@vger.kernel.org, Bo Shen , Thomas Petazzoni , linux-arm-kernel@lists.infradead.org, Robert Nelson , Tim Niemeyer List-Id: devicetree@vger.kernel.org --YZ5djTAD1cGYuMQK Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable 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: >=20 > > Hi Boris, > >=20 > > 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: > > > > [...] > > > >=20 > > > >>>>>>> + - 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 > > > >>>>>>=20 > > > >>>>>> These are properties of the panel and should be obtained from > > > >>>>>> the panel directly rather than an additional cell in this spec= ifier. > > > >>>>>=20 > > > >>>>> Okay. > > > >>>>> What's the preferred way of doing this ? > > > >>>>> What about defining an rgb-mode property in the panel node. > > > >>>>=20 > > > >>>> 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 a= lready > > > >>>> covered. > > > >>=20 > > > >> 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. > > > >=20 > > > > Yes, I agree that bps is not a good fit for what you need here. > > >=20 > > > Okay, then I think we can replace bpc and color_formats by a bus_form= ats > > > 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. > > >=20 > > > 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. > >=20 > > I think it is, but just to make sure I understand you correctly, could = you=20 > > just show how the drm_display_info structure would look like ? > >=20 >=20 > 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. >=20 > [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? Thierry --YZ5djTAD1cGYuMQK Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBAgAGBQJTzQO9AAoJEN0jrNd/PrOhdGMP/1zw1jrjhI+/9vr39+6aOHNc b4NI71DFifeBrwY2uZMClkJkPxv7NX2xtDw2QsyQor69Lv3v/V/oKvDFoEQEO2UD 4QqzrdO3WdERY1UGmGE5jHWk1FQqbpB7FThhDYj37E/+bP5wYOQBWnHV/bTTN5xZ W3awOzTjG50pb4XUqnh9v2lIt/gTPWgT8ZAWHUhy9gL9mlqLwhSDA6dvBNcReGFh Z8AZ/dmOVG2UyMwK6vApGHmp3vSw/etHYl0KwFtjLfm1Y+lOt5/4TZDt9kPZGbeG cmyO2Yyr1njABRKV99Vh30nBZe1kXaDGq1k3pBlWWPJkJwVPvru8xelq6uyTCSzl KWO1ej/63BafYd9ErNK9YzJrC4O+Aub0OLrc2Oi7pwgtDeQ/BcX30jjafRX4nknU zJsMbVvXb0WzLmBhXrGB/eosMylA+hmTWCqNxU4RJQBRMrv+1DENTwPaE+x8kYQD UFwFDedDLNEIsAMBrSAPdxV6uOIvXfV22eWq3LFVlU1nzxYobr5VWYzTdWXMQlRo PUrMlv42EZtWNlRKo/wK1gl+CpowbpMY4/7oKmTKG3ZBSsUgyWC+Om5eWD7cHE+b zCbk5hiIwRgUvfI6mpWMbffjgz0GX5DqqdepX3Zd6EMewZKFNM7VdJd2YM4hacKm jtI6PpYL2HkFkxqCGQM0 =5ebJ -----END PGP SIGNATURE----- --YZ5djTAD1cGYuMQK--