On Tue, Aug 12, 2014 at 07:15:41AM -0700, Alexandre Courbot wrote: > On Tue, Aug 12, 2014 at 3:01 AM, Mika Westerberg > <mika.westerberg@xxxxxxxxxxxxxxx> wrote: > > On Fri, Aug 08, 2014 at 02:36:02PM +0200, Linus Walleij wrote: > >> On Thu, Jul 24, 2014 at 5:51 PM, Tomasz Nowicki > >> <tomasz.nowicki@xxxxxxxxxx> wrote: > >> > >> > GPIO signaled events is quite new thing in Linux kernel. > >> > AFAIK, there are not many board which can take advantage of it. > >> > However, GPIO events are very useful feature during work on ACPI > >> > subsystems. > >> > >> Overall this seems like a pretty nice debug feature. > >> > >> > This commit emulates GPIO h/w behaviour and consists on read/write > >> > operation to debugfs file. GPIO device instance is still required in DSDT > >> > table along with _AEI resources and event methods. > >> > > >> > Reading from file provides pin to GPIO device map e.g. : > >> > $ cat /sys/kernel/debug/acpi/gpio_event > >> > GPIO device name: /__SB.GPI0 > >> > Available GPIO pin map: > >> > /__SB.GPI0 <-> pin 0x100 > >> > > >> > Based on that, user can trigger method corresponding to device pin number: > >> > $ echo "/__SB.GPI0 0x100" > /sys/kernel/debug/acpi/gpio_event > >> > >> I need input from Rafael and Mika as to whether this is a > >> good interface. > > > > Maybe it would make sense to move this into drivers/gpio/gpiolib-acpi.c > > and hide it behind some Kconfig entry? > > I actually like that this feature is contained in its own file - it > makes it easier to Kconfig-isolate and keeps the base ACPI code short > and readable. We spent some effort decoupling the sysfs and legacy > interfaces from the main gpiolib source file, let's keep that policy > going. ;) Well, OK but then it needs to make some functions available through the private gpiolib.h so that the gpiolib-acpi.c is able to call them. Of course it depends on whether the idea of exporting debugfs entries from acpi_gpiochip_request_interrupt() instead is going to be implemented. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
