From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH 1/4] ARM: dts: am437x-gp-evm: add HDMI support Date: Thu, 12 Dec 2019 09:31:10 -0800 Message-ID: <20191212173110.GA35479@atomide.com> References: <20191125131100.9839-1-tomi.valkeinen@ti.com> <20191212172104.GY35479@atomide.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20191212172104.GY35479@atomide.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, dri-devel@lists.freedesktop.org, robh+dt@kernel.org, linux-omap@vger.kernel.org List-Id: linux-omap@vger.kernel.org * Tony Lindgren [191212 17:21]: > Hi, > > * Tomi Valkeinen [191125 05:11]: > > Add HDMI support for AM437x GP EVM. The HDMI uses SiI9022 HDMI encoder, > > and is mutually exclusive with the LCD. The choice between LCD and HDMI > > is made by booting either with am437x-gp-evm.dtb or > > am437x-gp-evm-hdmi.dtb. > > So Linux kernel needs a new board device tree file to toggle a GPIO line > to switch between LCD mode and HDMI? > > That does not sound very user friendly for something that's supposed > to be hot pluggabe :) > > > +/* Override SelLCDorHDMI from am437x-gp-evm.dts to select HDMI */ > > +&gpio5 { > > + p8 { > > + output-low; > > + }; > > +}; > > How about just leave the gpio unconfigured and document that a userspace > tool or /sys/kernel/debug/gpio is needed to toggle between the modes? Adding also Linus Walleij to Cc in case he has some ideas here. Anyways, I'm applying the changes to dra76-evm am57xx-idk-common into omap-for-v5.6/dt as they have no GPIO pin limitation. I'd like to hear comments from folks on the first two though. Regards, Tony