[U-Boot] [PATCH v6 11/20] tegra: fdt: Add clock bindings for Tegra2 Seaboard

[Simon Glass]

Hi Tom,

On Mon, Mar 5, 2012 at 12:46 PM, Tom Rini <trini at ti.com> wrote:
> On Tue, Feb 28, 2012 at 10:41:15AM -0800, Stephen Warren wrote:
>> Simon Glass wrote at Tuesday, February 28, 2012 11:37 AM:
>> > On Tue, Feb 28, 2012 at 10:31 AM, Stephen Warren <swarren at nvidia.com> wrote:
>> > > Simon Glass wrote at Tuesday, February 28, 2012 10:38 AM:
>> > > ...
>> > >> I am going to add your binding, less the #clock-cells which U-Boot
>> > >> currently can't support because it conflicts with the C preprocessor
>> > >> (at some point I may look at a patch to use sed or some other means of
>> > >> avoiding this).
>> > >
>> > > Out of curiosity, why does the C preprocessor come into it? Is U-Boot's
>> > > build process running cpp on the .dts files or something? That's non-
>> > > standard, although perhaps it could be a useful standard...
>> >
>> > Yes, but at the moment we only use it for '/include/ ARCH_CPU_DTS'.
>>
>> Uggh. That's going to make the device tree files look different between
>> the kernel and U-Boot:-( With # disallowed in particular, it's going to
>> prevent U-Boot from /ever/ using the correct protocols for parsing the
>> device tree. This seems like an extremely bad idea.
>
> Keeping my TI hat on, I think it'd be a bad idea to have dts stuff
> divergent from the kernel.  Have you raised the problem you're trying to
> solve to the general DT gurus?  My very high level hope is that someday
> we can have them shared between kernel and u-boot (either directly or
> something silly like a .dtss that spits out a kernel dts and a u-boot
> dts).  Going with a manual sync from kernel form to u-boot form seems
> like adding a burden on ourselves we might not have to.

I agree, of course. I think the best solution may be to implement
search paths in dtc. I sent a patch today so let's see what people
think.

It is even worse when we copy the .dts and .dtsi files somewhere else
(e.g. losing the original directory tree relationship by copying all
into one directory).

Regards,
Simon

>
> --
> Tom