[PATCH 1/2] pinctrl: add pinctrl-mxs support

[Linus Walleij]

On Tue, Apr 24, 2012 at 4:25 PM, Dong Aisheng
<aisheng.dong at freescale.com> wrote:
> On Tue, Apr 24, 2012 at 09:26:51PM +0800, Shawn Guo wrote:
>> On Tue, Apr 24, 2012 at 03:07:35PM +0200, Linus Walleij wrote:
>> > Hm, that's pretty interesting - but are imx and mxs even going to use the
>> > same driver then? Maybe I'm not following - are they similar
>> > in all other aspects than for this pin config stuff?
>> >
>> The mach-mxs (i.MX23 and i.MX28) is a totally different sub-architecture
>> from mach-imx.  Freescale acquired it from SigmaTel a few years back.
>> These two sub-architectures have completely different pin controllers.
>> So, no, they are not going to use the same pinctrl driver but two
>> different ones, pinctrl-mxs and pinctrl-imx.
>>
>> The only common aspect is both two controllers only supports pin basis
>> configuration (no hardware pingroup).  I think many other
>> sub-architectures including omap are same on this aspect.
>>
> The key point is not the hw difference, it is if we can find common part
> on a higher abstract layer, that's what a subsystem or a good
> designed common driver do, right?

Yep if there are similarities between i.MX and MXS I guess these
similarities will be between these and Tegra/OMAP etc also.

And then it goes into the pinctrl subsystem of course.

> My key point is to do common things like dt binding in pinctrl-imx and
> handle hw difference in each SoC pinctrl driver.

I think we tried to create common device tree bindings and
partly failed to reach common ground so we now have a compromise
where each driver needs to plug in its own parser in the
dt_node_to_map() and dt_free_map() hooks...

(OMG these two are not kerneldoc:ed, I need to poke Stephen.)

Yours,
Linus Walleij