Messages in this thread | | | Date | Mon, 18 Aug 2014 11:31:53 +0200 | From | Tomasz Nowicki <> | Subject | Re: [RFC] ACPI: Add GPIO-signaled event simulator. |
| |
On 12.08.2014 16:15, Alexandre Courbot wrote: > On Tue, Aug 12, 2014 at 3:01 AM, Mika Westerberg > <mika.westerberg@linux.intel.com> 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@linaro.org> 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. ;)
I will keep that isolation.
> > Maybe the source file could be renamed to highlight the fact this is > an ACPI-only feature, e.g. gpio-acpi-evt-emu.c? (let's also use '-' as > separator since this is what all GPIO drivers do). >
Yes, I will rename it as you suggested. I will address all comments based on feedback I have got and send another version. Thanks!
Regards, Tomasz Nowicki
| |