Re: [PATCH v3 3/6] gpio: max77620: Don't set of_node

Dmitry Osipenko
2020-07-09T10:38:31Z

09.07.2020 12:07, Andy Shevchenko пишет:
> On Thu, Jul 9, 2020 at 12:44 AM Dmitry Osipenko <digetx@gmail.com> wrote:
>> 08.07.2020 23:57, Andy Shevchenko пишет:
>>> On Wednesday, July 8, 2020, Dmitry Osipenko <digetx@gmail.com
>>> <mailto:digetx@gmail.com>> wrote:
>
> ...
>
>>> I gave a second look and I think my suggestion is wrong. Here is an
>>> interesting propagation of the parent device node to its grand son,
>>> leaving son’s one untouched. Original code has intentions to do that way.
>>
>> The [1] says that gpio_chip.parent should point at the "device providing
>> the GPIOs".
>
> Yes, physical device I believe.
>
>> That's the pdev->dev.parent in the case of this driver.
>> MAX77620 is an MFD PMIC device that has virtual sub-devices like GPIO
>> controller, PINCTRL and RTC. The MFD is the parent device that provides
>> the GPIOs [2].
>>
>> [1]
>> https://elixir.bootlin.com/linux/v5.8-rc3/source/include/linux/gpio/driver.h#L276
>>
>> [2]
>> https://elixir.bootlin.com/linux/v5.8-rc3/source/arch/arm64/boot/dts/nvidia/tegra210-p2180.dtsi#L48
>>
>> I think the old code was wrong and this patch is correct, please correct
>> me if I'm missing something.
>
> Hmm... I have checked through GPIO drivers I have knowledge of / care
> about and PMIC ones do like you suggested in this patch, the rest
> (which are instantiated from MFD) take a virtual platform device.
>
> Looking at DT excerpt I think you're rather right than wrong, so I
> leave it to you and maintainers.
> Thanks!

Okay, waiting for the maintainers then :)

Thank you very much for the review!