From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Subject: Re: [RESEND PATCH v3 06/11] drm: add DT bindings documentation for atmel-hlcdc-dc driver Date: Mon, 21 Jul 2014 14:16:42 +0200 Message-ID: <1616525.bcHvjgnZ4T@avalon> References: <1404751384-5077-1-git-send-email-boris.brezillon@free-electrons.com> <20140721115737.1377a5fd@bbrezillon> <20140721121245.GA15238@ulmo> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0790857044==" Return-path: In-Reply-To: <20140721121245.GA15238@ulmo> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Thierry Reding Cc: Mark Rutland , devicetree@vger.kernel.org, Nicolas Ferre , dri-devel@lists.freedesktop.org, Alexandre Belloni , 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 --===============0790857044== Content-Type: multipart/signed; boundary="nextPart2318571.3OQhy1Jbvp"; micalg="pgp-sha1"; protocol="application/pgp-signature" --nextPart2318571.3OQhy1Jbvp Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="us-ascii" 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:= > >>>> [...] > >>>>=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] (excep= t > > that color_formats and bpc have not be removed yet), and [1] is jus= t > > 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 > =09+ const enum video_bus_format *bus_formats; > =09+ int nbus_formats; >=20 > Do we really need more than one? We do if we want to replace the color_formats and bpc fields. =2D-=20 Regards, Laurent Pinchart --nextPart2318571.3OQhy1Jbvp Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. 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