From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Subject: Re: [PATCH 1/4] ARM: dts: am437x-gp-evm: add HDMI support Date: Fri, 13 Dec 2019 14:28:45 +0200 Message-ID: <20191213122845.GD4860@pendragon.ideasonboard.com> References: <20191125131100.9839-1-tomi.valkeinen@ti.com> <20191212172104.GY35479@atomide.com> <20191212173110.GA35479@atomide.com> <20191213104204.GB4860@pendragon.ideasonboard.com> <2f5cfca4-d36d-da2d-59ba-b76669daeded@ti.com> <20191213114207.GC4860@pendragon.ideasonboard.com> <36d8dde1-1a76-5a5f-2a41-8bc52dfcf2fa@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <36d8dde1-1a76-5a5f-2a41-8bc52dfcf2fa@ti.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Tomi Valkeinen Cc: mark.rutland@arm.com, devicetree@vger.kernel.org, Tony Lindgren , dri-devel@lists.freedesktop.org, robh+dt@kernel.org, linux-omap@vger.kernel.org List-Id: linux-omap@vger.kernel.org Hi Tomi, On Fri, Dec 13, 2019 at 02:04:30PM +0200, Tomi Valkeinen wrote: > On 13/12/2019 13:42, Laurent Pinchart wrote: > > On Fri, Dec 13, 2019 at 12:56:31PM +0200, Tomi Valkeinen wrote: > >> On 13/12/2019 12:42, Laurent Pinchart wrote: > >> > >>>> I think the correct way would be to have DRM framework understand that we have two displays, which > >>>> are mutually exclusive, and the display pipeline drivers would have the means to switch the gpio. > >>>> And that the display setup could be communicated properly to the userspace, and the userspace would > >>>> understand it. I don't think any of those exists. > >>> > >>> Isn't this what possible_clones in drm_encoder is for ? It notifies > >>> userspace of mutual exclusions between encoders. > >> > >> Hmm, how would that work here? Isn't encoder cloning about having two encoders, which take the input > >> from the same video source, and then outputting to two displays? > > > > That's the idea. If you have one encoder for HDMI and one for the panel, > > you can mark them as non-clonable, and then only one of the two can be > > active at a time. > > We have a single DPI output from the SoC. That goes to the panel, or to SiI9022 bridge, depending on > the GPIO switch. > > So... In the DT file, we would have multiple endpoints in the same output port in DSS, one going to > the panel, one to the SiI9022? omapdrm could then create two encoders, one abstracting the DPI > output and the connection to the panel, one abstracting the DPI output and SiI9022? That's the idea, yes. > And then someone would need to handle the GPIO, and set it based on the output used. These kind of > gpios are always difficult, as they don't belong anywhere =). https://lore.kernel.org/lkml/20191211061911.238393-5-hsinyi@chromium.org/ Still, the infrastructure in omapdrm would need quite a bit of work. We're just about to get a helper layer for linear pipelines merged, and we already need to go one step further :-) -- Regards, Laurent Pinchart