Re: pinctrl-amd: What hardware does it apply to?

From: Andrew Cooks
Date: Thu Dec 21 2017 - 20:17:51 EST


Hi Christian

On 21/12/17 23:02, Christian Lamparter wrote:
> On Thursday, December 21, 2017 8:25:03 AM CET Andrew Cooks wrote:
>> I'm working on gpio for an AMD Family 16h Model 30h system[1].
>> The SoC is the same as the GX412-TC used in the PC Engines APU2.
>>
>> There is an out-of-tree gpio driver (gpio-amd) for this SoC in the
>> meta-amd yocto layer[2]. Another driver (gpio-sb8xx) was submitted
>> for upstream inclusion, but was knocked back with the suggestion
>> that pinctrl is the way forward[3].
>>
>> I would much prefer to use a mainline driver for the system I'm
>> working on, so I'm looking at the pinctrl-amd driver to see
>> whether it applies to our SoC, or whether it could be extended,
>> or used as starting point for a new driver.
>>
>> The out-of-tree drivers apply to the GX412-TC SoC and uses PCI
>> for probing:
>
> Just a FYI: due to these difficulties with getting a gpio driver
> upstream, Alan Mizrahi upstreamed an in-kernel led-apu.c driver [0]
> that sort of bypasses the whole pinctrl vs gpio issue.

Thanks, I saw that and was somewhat surprised to see it accepted.

>
> If you are just after LEDs or gpio-keys you probably can go the same
> route?

I could. The gpio-amd driver in the meta-amd yocto layer, which is already functional, is another workable alternative. However, I would prefer the more elegant mainline pinctrl solution, if it's attainable.

Thanks

Andrew