Messages in this thread |  | | From | Andy Shevchenko <> | Date | Thu, 9 Jul 2020 12:07:44 +0300 | Subject | Re: [PATCH v3 3/6] gpio: max77620: Don't set of_node |
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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!
-- With Best Regards, Andy Shevchenko
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