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 14:55:23 +0200 Message-ID: <20140721125522.GE15238@ulmo> References: <1404751384-5077-1-git-send-email-boris.brezillon@free-electrons.com> <20140721115737.1377a5fd@bbrezillon> <20140721121245.GA15238@ulmo> <1616525.bcHvjgnZ4T@avalon> <20140721143428.078b68a4@bbrezillon> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1413851757==" Return-path: In-Reply-To: <20140721143428.078b68a4@bbrezillon> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Boris BREZILLON Cc: Mark Rutland , devicetree@vger.kernel.org, Nicolas Ferre , dri-devel@lists.freedesktop.org, Alexandre Belloni , Laurent Pinchart , Bo Shen , Lee Jones , Jean-Jacques Hiblot , Samuel Ortiz , Tim Niemeyer , Jean-Christophe Plagniol-Villard , linux-pwm@vger.kernel.org, Pawel Moll , Ian Campbell , Rob Herring , Andrew Victor , linux-arm-kernel@lists.infradead.org, Thomas Petazzoni , Kumar Gala List-Id: devicetree@vger.kernel.org --===============1413851757== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="0H629O+sVkh21xTi" Content-Disposition: inline --0H629O+sVkh21xTi Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Jul 21, 2014 at 02:34:28PM +0200, Boris BREZILLON wrote: > On Mon, 21 Jul 2014 14:16:42 +0200 > Laurent Pinchart wrote: >=20 > > Hi Thierry, > >=20 > > 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: > > > >>>> [...] > > > >>>>=20 > > > >>>>>>>>>> + - atmel,panel: Should contain a phandle with 2 parameter= s. > > > >>>>>>>>>> + The first cell is a phandle to a DRM panel device > > > >>>>>>>>>> + The second cell encodes the RGB mode, which can take t= he > > > >>>>>>>>>> following values: > > > >>>>>>>>>> + * 0: RGB444 > > > >>>>>>>>>> + * 1: RGB565 > > > >>>>>>>>>> + * 2: RGB666 > > > >>>>>>>>>> + * 3: RGB888 > > > >>>>>>>>>=20 > > > >>>>>>>>> These are properties of the panel and should be obtained fr= om > > > >>>>>>>>> the panel directly rather than an additional cell in this > > > >>>>>>>>> specifier. > > > >>>>>>>>=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 co= uld > > > >>>>>>> be used for this. Alternatively, maybe we could extend the li= st > > > >>>>>>> of color formats that go into drm_display_info.color_formats? > > > >>>>>>> RGB444 is already covered. > > > >>>>>=20 > > > >>>>> I forgot to ask about bpc meaning. If, as I think, it means "bi= ts > > > >>>>> 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 bi= ts. > > > >>>>=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_formats table containing all supported formats, and use an en= um > > > >>> (something similar to v4l2_mbus_pixelcode defined in v4l2-mediabu= s.h > > > >>> [1]) to list the available formats. > > > >>>=20 > > > >>> As this implies quite a few changes in crtc core and some drm dri= vers > > > >>> (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, c= ould > > > >> you just show how the drm_display_info structure would look like ? > > > >=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 > > >=20 > > > Quoting from your paste: > > >=20 > > > + const enum video_bus_format *bus_formats; > > > + int nbus_formats; > > >=20 > > > Do we really need more than one? > >=20 > > We do if we want to replace the color_formats and bpc fields. > >=20 >=20 > Yes, that's what I was about to answer :-). Maybe we don't need to replace color_formats and bpc field immediately. That could be done in a follow-up patch. Thierry --0H629O+sVkh21xTi Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBAgAGBQJTzQ26AAoJEN0jrNd/PrOhXpwP/1jw6XI6V+3qM3p3tiungob8 C19a/s9lrO3kteMAy5wG5WmV5/WoLUrqOY4hTqJPHUgzck0x8oOI3YG7/pbseP9u Yg44Ohd4Xz4WTU9h/ZoI4P521facXzfMVhAgN/SfJl+t/2i7aqL/LZCn7qX9MMFz UK/guAGRfNgOLhJ4moMZEcs8VE1++XTVGUL3vVBNBMjp0YCavnPxvhhaxfZVttIm V6FUxCQ4M6ou0mLyU9QBEp5UiBC9elckcBM38p+OkN5X0IoY59e7hBL5QpUqzSKl PeRFXCdvG6JsKzcyzOOSxAlhsJLOcciuvVtLz38aN1MXTb6p31JlS8XZUVpNP6K9 GED6dG0SPQ1EAiuM2eQ7xzB0b69cyfuWXQNT4tIDrwPM+KPt0TTwCYq7odNiMXD5 3ICmpH3fOYS3Od1ux0eXLV4+nUvnSX8KmfD1GlBeXqne9qwP/ipgoWPvKFRu5yvI Ov0Rvh6eiqZwb09MSLmb9o0MUoqWnINy8SvxyKhd+OQCwsFTtYzqYO49KE66RhYy 2coZ0W00bGnDLJmt0vi38hwdP4gd9LaaB0czxb7F6Tcvj429Ebf9XK7nET32RdvG dfUALqRAx4NlPPtPsWFab2hGWOT3PH/xI7D8Wp5009n7JCT2jS6rD5Pk3YoDncA7 zSjXvY2GBTd9tnvJJuId =xLJw -----END PGP SIGNATURE----- --0H629O+sVkh21xTi-- --===============1413851757== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel --===============1413851757==--