From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mitch Bradley Date: Mon, 08 Oct 2012 16:34:12 +0000 Subject: Re: [PATCH 1/2 v6] of: add helper to parse display timings Message-Id: <50730084.3060805@firmworks.com> List-Id: References: <1349373560-11128-1-git-send-email-s.trumtrar@pengutronix.de> <1349373560-11128-2-git-send-email-s.trumtrar@pengutronix.de> <506F0833.1090704@wwwdotorg.org> <1349686878.3227.40.camel@deskari> In-Reply-To: <1349686878.3227.40.camel@deskari> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Tomi Valkeinen Cc: linux-fbdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, Laurent Pinchart , Steffen Trumtrar , Guennadi Liakhovetski , linux-media-u79uwXL29TY76Z2rM5mHXA@public.gmane.org On 10/7/2012 11:01 PM, Tomi Valkeinen wrote: > On Mon, 2012-10-08 at 10:25 +0200, Guennadi Liakhovetski wrote: > >> In general, I might be misunderstanding something, but don't we have to >> distinguish between 2 types of information about display timings: (1) is >> defined by the display controller requirements, is known to the display >> driver and doesn't need to be present in timings DT. We did have some of >> these parameters in board data previously, because we didn't have proper >> display controller drivers... (2) is board specific configuration, and is >> such it has to be present in DT. >> >> In that way, doesn't "interlaced" belong to type (1) and thus doesn't need >> to be present in DT? > > As I see it, this DT data is about the display (most commonly LCD > panel), i.e. what video mode(s) the panel supports. If things were done > my way, the panel's supported timings would be defined in the driver for > the panel, and DT would be left to describe board specific data, but > this approach has its benefits. > > Thus, if you connect an interlaced panel to your board, Do interlaced panels exist? I have never seen one. you need to tell > the display controller that this panel requires interlace signal. Also, > pixel clock source doesn't make sense in this context, as this doesn't > describe the actual used configuration, but only what the panel > supports. > > Of course, if this is about describing the hardware, the default-mode > property doesn't really fit in... > > Tomi > > > > _______________________________________________ > devicetree-discuss mailing list > devicetree-discuss@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/devicetree-discuss >