Re: Question: DTS and redundant board IDs

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

On 05/04/2012 02:47 AM, David Lanzendörfer wrote:
> Hi
> Thanks a lot for your answer!
> 
>> The machine ID isn't relevant with device tree; just supply the correct
>> content in device tree and it'll work out fine.
>
> How do I tell the kernel on which device within the tree it's running on?

The kernel shouldn't really care; the DT support is designed to mostly
only directly know about Tegra20 vs. Tegra30.

> Where can I get the correct string from for adding into pinmux_configs?

You'll have to create it yourself by translating the content of the
board pinmux file in whatever kernel the board currently uses.

I do have a very rough Python script that mostly converts the format,
but it's got a lot of warts. I can email that to you directly if you
want. You will need to manually patch up some of the results though.

> In upstream there are strings like "compulab,trimslice" or "nvidia,harmony".
> Where can I extract the correct string for adam?

You will have to create it yourself based on the vendor and board name.
I think what you want is something like:

compatible = "notionink,adam", "nvidia,tegra20";

> Sry, but until now, I've just used the hw id and it worked... :-/
> 
> Is there a documentation and I'm just unable to find it?

In the kernel source, Documentation/devicetree/bindings describes the
format of all the device tree nodes. See e.g.
pinctrl/nvidia,tegra20-pinmux.txt. Also, be sure to become familiar with
how the other Tegra device trees are constructed; see
arch/arm/board/dts/tegra*.