linux/include
Felipe Balbi c4b5be98fe gpiolib: introduce set_debounce method
A few architectures, like OMAP, allow you to set a debouncing time for the
gpio before generating the IRQ.  Teach gpiolib about that.

Mark said:
: This would be generally useful for embedded systems, especially where
: the interrupt concerned is a wake source.  It allows drivers to avoid
: spurious interrupts from noisy sources so if the hardware supports it
: the driver can avoid having to explicitly wait for the signal to become
: stable and software has to cope with fewer events.  We've lived without
: it for quite some time, though.

David said:
: I looked at adding debounce support to the generic GPIO calls (and thus
: gpiolib) some time back, but decided against it.  I forget why at this
: time (check list archives) but it wasn't because of lack of utility in
: certain contexts.
:
: One thing to watch out for is just how variable the hardware capabilities
: are.  Atmel GPIOs have something like a fixed number of 32K clock cycles
: for debounce, twl4030 had something odd, OMAPs were more like the Atmel
: chips but with a different clock.  In some cases debouncing had to be
: ganged, not per-GPIO.  And so forth.

Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: David Brownell <david-b@pacbell.net>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:42 -07:00
..
acpi ACPICA: Update version to 20100428. 2010-05-06 03:05:54 -04:00
asm-generic gpiolib: introduce set_debounce method 2010-05-27 09:12:42 -07:00
crypto crypto: skcipher - Add ablkcipher_walk interfaces 2010-05-19 14:13:07 +10:00
drm Merge branch 'drm-for-2.6.35' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2010-05-21 11:14:52 -07:00
keys
linux gpiolib: introduce set_debounce method 2010-05-27 09:12:42 -07:00
math-emu
media V4L/DVB: v4l2-subdev.h: Add support for enum_dv_preset 2010-05-19 12:59:01 -03:00
mtd
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 2010-05-25 16:59:51 -07:00
pcmcia pcmcia: remove unused mem_op.h 2010-05-10 10:23:20 +02:00
rdma IB/core: Allow device-specific per-port sysfs files 2010-05-21 10:34:44 -07:00
rxrpc
scsi [SCSI] libfc: Move the port_id into lport 2010-05-16 22:22:34 -04:00
sound Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6 2010-05-20 09:41:44 -07:00
trace Merge branch 'kvm-updates/2.6.35' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2010-05-21 17:16:21 -07:00
video fbdev: move FBIO_WAITFORVSYNC to linux/fb.h 2010-05-25 08:07:09 -07:00
xen
Kbuild