Re: [PATCH 2/2] ARM: tegra: Add high speed UARTs to Jetson TK1 device tree

[Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>]

On 01/19/2016 06:12 AM, Ralf Ramsauer wrote:
> This patch enables the APB DMA high speed UARTs of the Jetson TK1.

In the cover letter, you mentioned that these ports are exposed on the 
expansion connector. It'd be useful to mention that fact here too, since 
the cover letter doesn't make it into the git commit log.

However, given that, I don't think we should apply this patch. We can't 
know ahead of time what hardware is connected to the expansion header; 
the pins aren't dedicated to be serial ports (they could be GPIOs and 
probably other functions too depending on the pinmux settings), and 
different people will connect different hardware or none at all. Hence, 
the default DT should not enable IO controllers for the pins on the 
expansion connector. The best approach these days is to use DT overlays. 
You may need to add some "hooks" into the Tegra base DT files to allow 
overlays to be used; they weren't written with overlays in mind.