On Fri, Mar 10, 2023 at 12:42 PM Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> wrote: > > On Thu, Mar 09, 2023 at 02:40:51PM +0100, Benjamin Tissoires wrote: > > While trying to set up an SSDT override for a USB-2-I2C chip [0], > > I realized that the function acpi_gpiochip_find() was using the parent > > of the gpio_chip to do the ACPI matching. > > > > This works fine on my icelake laptop because AFAICT, the DSDT presents > > the PCI device INT3455 as the "Device (GPI0)", but is in fact handled > > by the pinctrl driver in Linux. > > The pinctrl driver then creates a gpio_chip device. This means that the > > gc->parent device in that case is the GPI0 device from ACPI and everything > > works. > > > > However, in the hid-cp2112 case, the parent is the USB device, and the > > gpio_chip is directly under that USB device. Which means that in this case > > gc->parent points at the USB device, and so we can not do an ACPI match > > towards the GPIO device. > > > > I think it is safe to resolve the ACPI matching through the fwnode > > because when we call gpiochip_add_data(), the first thing it does is > > setting a proper gc->fwnode: if it is not there, it borrows the fwnode > > of the parent. > > > > So in my icelake case, gc->fwnode is the one from the parent, meaning > > that the ACPI handle we will get is the one from the GPI0 in the DSDT > > (the pincrtl one). And in the hid-cp2112 case, we get the actual > > fwnode from the gpiochip we created in the HID device, making it working. > > > > Link: https://lore.kernel.org/linux-input/20230227140758.1575-1-kaehndan@xxxxxxxxx/T/#m592f18081ef3b95b618694a612ff864420c5aaf3 [0] > > Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> > > Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> > Thanks to both of you for the reviews. Andy, should I resend a v2 with the rev-by from Mika and the Ice Lake changes? Cheers, Benjamin
