[U-Boot] [PATCH v3 06/11] arm: rpi: Enable device tree control for Rasberry Pi

Simon Glass
2015-08-14T19:20:04Z

Hi Stephen,

On 10 August 2015 at 21:47, Stephen Warren <swarren@wwwdotorg.org> wrote:
> On 08/07/2015 07:42 AM, Simon Glass wrote:
>> Enable device tree control so that we can use driver model fully and avoid
>> using platform data.
>
> I'm still not convinced about this change.
>
> Re: the commit message about: What about the driver model is not being
> fully used without DT?

Device tree control?

>
> Overall: What advantage does using DT have to either a developer or an
> end-user?
>
> I don't believe this patch fixes and bugs or enables any new features
> for an end-user.
>
> From the maintainer perspective: It seems to me that it's far simpler to
> have a tiny struct for each device in the C code than to pull in a whole
> slew of DT parsing cruft just to work out the same struct at run-time.
> As such, this patch can only make it harder to maintain the code since
> there's more of it, and it's more complex.
>
> I just don't see the advantage of switching to DT for U-Boot control.

It allows us to share configuration with the kernel (same device tree
file). This should be more familiar to people coming from there than
our own configuration system. It's nice to have all the configuration
in one place. We can then avoid using platform data in U-Boot unless
it is necessary.

I really don't like the idea of filling up the code with platform data
when that approach has already been rejected by Linux.

Regards,
Simon