[PATCH RFC] gpio: Fix probing of gpio-hogs

[Chris Webb]

Hi Simon,

Simon Glass <sjg at chromium.org> wrote:

> Well, yes, mt7981_pinctrl is wrong since it is not actually binding
> the GPIO devices until it itself is probed. It should do it when it is
> bound.

Oh I see! Yes, I can see the mtk_gpiochip_register(dev) in  
mtk_pinctrl_common_probe() exactly as you say.

> Better still, those GPIO devices should be in the devicetree and bound
> automatically by driver model. But, sigh, I see that there is no
> compatible string in the gpio subnode of pinctrl at 11d00000. It should
> really have one and avoid all this pointless code and problems.
>
> mtk_pinctrl_common_probe() is misnamed, as it actually binds and then  
> probes.
>
> So (unless Linux allows a patch to add a compatible string) it needs a
> new mtk_pinctrl_common_bind() (called from mtk_pinctrl_mt7981_bind())
> which calls mtk_gpiochip_register(). Then you won't need to add your
> dev_or_flags() into mtk_pinctrl_mt7981_bind().

Yes, that makes complete sense. Many thanks! I'm very happy to write that  
patch and grab back the physical hardware to double-check on if you like?  
(Or equally happy to leave it if you'd prefer to fix yourself?)

Presumably it needs to apply to every mtk soc that uses  
mtk_pinctrl_common_probe() as they'll all be affected by this problem.

Best wishes,

Chris.