On Thu, Jul 9, 2020 at 12:44 AM Dmitry Osipenko <digetx@xxxxxxxxx> wrote: > 08.07.2020 23:57, Andy Shevchenko пишет: > > On Wednesday, July 8, 2020, Dmitry Osipenko <digetx@xxxxxxxxx > > <mailto:digetx@xxxxxxxxx>> 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
