Re: [RFC] tegra: dpaux: pinctrl proposal

[Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>]

On 22/05/15 08:03, Linus Walleij wrote:
> On Thu, May 21, 2015 at 4:03 PM, Thierry Reding
> <thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> 
>>>> I don't see any conceptual reason why the driver that binds to that node
>>>> can't register as both a pinctrl driver plus anything else it needs to.
> (...)
>>> Looking at it there should not be a problem here with regard to the
>>> driver_data member of the device struct and so I don't see why the
>>> tegra_dpaux_probe() could not call pinctrl_register() to register the
>>> device.
>>
>> Yes, I think that'd be the best solution.
> 
> I'm pretty much ready to go to any compromises to get DRM/GPU
> drivers to use internal kernel subsystems. The tendency there
> is to reimplement all kernel driver frameworks and hammer registers
> they need to access.

Thanks Linus, but after looking at this further I don't think this
approach will work after all. In order to call pinctrl_register() from
outside the pinctrl directory, also means exposing the pinctrl_dev and
pinctrl_desc structures and so this will get messy. Or at least a bigger
churn than I would have hoped for.

Thierry, what if we add a drivers/pinctrl/pinctrl-tegra-dpaux.c and then
simply call platform_device_register_data() from tegra_dpaux_probe() to
register the device? I could still use the parent of_node to match the
platform data for the dpaux pin controller.

Cheers
Jon