On Mon, Mar 30, 2015 at 03:55:14PM +0300, Octavian Purdila wrote: > On Mon, Mar 30, 2015 at 12:52 PM, Mika Westerberg > <mika.westerberg@xxxxxxxxxxxxxxx> wrote: > > On Fri, Mar 27, 2015 at 11:36:25AM +0100, Linus Walleij wrote: > >> On Fri, Mar 27, 2015 at 11:06 AM, Mika Westerberg > >> <mika.westerberg@xxxxxxxxxxxxxxx> wrote: > >> > On Thu, Mar 26, 2015 at 06:28:19PM +0200, Octavian Purdila wrote: > >> > >> >> For the sleep case I think the GPIO controller needs to do the pin > >> >> enable and set input direction operation in it's irq_bus_sync_unlock. > >> > > >> > I wonder how DT handles all this? Is it the boot firmware that sets up > >> > the pins accordingly or is there something we are missing? > >> > >> DT systems mostly do not have firmware for power usecases, they > >> handle it all using pin control. I would more say that is a feature of > >> all-SW systems without power-firmware ideas, without ACPI and > >> without PSCI (well PSCI systems do not care about much more > >> than CPU power down in firmware anyway...) > > > > OK, thanks. > > > > In case of ACPI (where firmware does lot more) it is supposed to > > configure pins based on what is connected, if the firmware knows that. > > Due to bugs in the boot firmware that obviously does not happen in all > > cases (like this one). > > > > Ah, interesting, I was not aware that the firmware was supposed to do > the pin configuration. In this case I think your patch can be merged > as it is Mika, mine doesn't make sense anymore. Unfortunately because of bugs we can't rely that the firmware (BIOS) gets those always right :-( > This particular case is special since we did not performed the tests > on a full system that has the component integrated. We instead used > and I2C to USB bridge to which we connected the component and we > loaded the ACPI table dynamically. Regardless of how did the device appear this always works: 1) request the GPIO (with GPIOD_IN) 2) convert it to IRQ using gpiod_to_irq() Since we cannot be sure that the firmware has configured the pin properly, rather than adding automatic IRQ <-> GPIO translation for ACPI GpioInt I think we are better off if drivers explictly request their GPIOs and configure them as needed. -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html