Re: [PATCH 1/4] ARM: dts: am437x-gp-evm: add HDMI support

[Tony Lindgren <tony@atomide.com>]

* Tony Lindgren <tony@atomide.com> [191212 17:21]:
> Hi,
> 
> * Tomi Valkeinen <tomi.valkeinen@ti.com> [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