linux/drivers
Mika Westerberg 473ed7be0d gpio / ACPI: Add support for ACPI GPIO operation regions
GPIO operation regions is a new feature introduced in ACPI 5.0
specification. This feature adds a way for platform ASL code to call back
to OS GPIO driver and toggle GPIO pins.

An example ASL code from Lenovo Miix 2 tablet with only relevant part
listed:

 Device (\_SB.GPO0)
 {
     Name (AVBL, Zero)
     Method (_REG, 2, NotSerialized)
     {
         If (LEqual (Arg0, 0x08))
         {
             // Marks the region available
             Store (Arg1, AVBL)
         }
     }

     OperationRegion (GPOP, GeneralPurposeIo, Zero, 0x0C)
     Field (GPOP, ByteAcc, NoLock, Preserve)
     {
         Connection (
             GpioIo (Exclusive, PullDefault, 0, 0, IoRestrictionOutputOnly,
                     "\\_SB.GPO0", 0x00, ResourceConsumer,,)
             {
                 0x003B
             }
         ),
         SHD3,   1,
     }
 }

 Device (SHUB)
 {
     Method (_PS0, 0, Serialized)
     {
         If (LEqual (\_SB.GPO0.AVBL, One))
         {
             Store (One, \_SB.GPO0.SHD3)
             Sleep (0x32)
         }
     }
     Method (_PS3, 0, Serialized)
     {
         If (LEqual (\_SB.GPO0.AVBL, One))
         {
             Store (Zero, \_SB.GPO0.SHD3)
         }
     }
 }

How this works is that whenever _PS0 or _PS3 method is run (typically when
SHUB device is transitioned to D0 or D3 respectively), ASL code checks if
the GPIO operation region is available (\_SB.GPO0.AVBL). If it is we go and
store either 0 or 1 to \_SB.GPO0.SHD3.

Now, when ACPICA notices ACPI GPIO operation region access (the store
above) it will call acpi_gpio_adr_space_handler() that then toggles the
GPIO accordingly using standard gpiolib interfaces.

Implement the support by registering GPIO operation region handlers for all
GPIO devices that have an ACPI handle. First time the GPIO is used by the
ASL code we make sure that the GPIO stays requested until the GPIO chip
driver itself is unloaded. If we find out that the GPIO is already
requested we just toggle it according to the value got from ASL code.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-03-14 17:25:02 +01:00
..
accessibility
acpi Revert "ACPI / sleep: pm_power_off needs more sanity checks to be installed" 2014-03-09 13:48:36 -07:00
amba
ata Merge branch 'for-3.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata 2014-03-08 11:52:45 -08:00
atm
auxdisplay
base PM / hibernate: Fix restore hang in freeze_processes() 2014-02-26 01:13:15 +01:00
bcma Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2014-01-30 17:20:32 -08:00
block Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2014-03-07 09:59:44 -08:00
bluetooth
bus drivers: bus: fix CCI driver kcalloc call parameters swap 2014-01-31 15:15:13 -08:00
cdrom Merge branch 'for-3.14/drivers' of git://git.kernel.dk/linux-block 2014-01-30 11:40:10 -08:00
char Char/Misc fixes for 3.14-rc3 2014-02-14 16:13:00 -08:00
clk Single fix for a clock driver merged in 3.14-rc1. Without this fix the 2014-03-08 10:51:30 -08:00
clocksource clocksource: Kona: Print warning rather than panic 2014-02-06 16:01:40 +01:00
connector
cpufreq cpufreq: Initialize governor for a new policy under policy->rwsem 2014-03-06 13:25:30 +01:00
cpuidle powerpc/powernv/cpuidle: Back-end cpuidle driver for powernv platform. 2014-01-29 17:02:24 +11:00
crypto crypto/nx/nx-842: Fix handling of vmalloc addresses 2014-02-11 11:24:49 +11:00
dca
devfreq Merge branches 'pm-cpufreq' and 'pm-devfreq' 2014-01-29 11:48:23 +01:00
dio
dma Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma 2014-03-01 21:30:43 -06:00
edac i7300_edac: Fix device reference count 2014-02-25 09:43:13 +01:00
eisa
extcon ASoC: dapm: Add locking to snd_soc_dapm_xxxx_pin functions 2014-02-20 18:40:07 +09:00
firewire Merge branch 'for-3.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2014-03-08 11:51:13 -08:00
firmware firmware/google: drop 'select EFI' to avoid recursive dependency 2014-01-27 21:02:40 -08:00
fmc drivers/fmc/fmc-write-eeprom.c: fix decimal permissions 2014-02-25 15:25:43 -08:00
gpio gpio / ACPI: Add support for ACPI GPIO operation regions 2014-03-14 17:25:02 +01:00
gpu Merge branch 'drm-fixes-3.14' of git://people.freedesktop.org/~agd5f/linux into drm-fixes 2014-03-07 09:27:22 +10:00
hid Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid 2014-02-18 16:29:46 -08:00
hsi
hv Drivers: hv: vmbus: Don't timeout during the initial connection with host 2014-02-07 08:27:34 -08:00
hwmon hwmon: (max1668) Fix writing the minimum temperature 2014-02-18 15:53:49 -08:00
hwspinlock
i2c i2c: mv64xxx: refactor message start to ensure proper initialization 2014-02-15 15:42:31 +01:00
ide drivers: ide: Include appropriate header file in ide-pio-blacklist.c 2014-01-28 23:35:09 -08:00
idle ACPI and power management updates for 3.14-rc1 2014-01-24 15:51:02 -08:00
iio iio:gyro: bug on L3GD20H gyroscope support 2014-02-18 10:24:49 +00:00
infiniband Merge git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2014-03-09 13:50:14 -07:00
input ASoC: dapm: Add locking to snd_soc_dapm_xxxx_pin functions 2014-02-20 18:40:07 +09:00
iommu drivers/iommu/omap-iommu-debug.c: fix decimal permissions 2014-02-25 15:25:42 -08:00
ipack
irqchip irq-metag*: stop set_affinity vectoring to offline cpus 2014-02-25 22:35:06 +00:00
isdn isdn/hisax: hex vs decimal typo in prfeatureind() 2014-02-06 21:18:06 -08:00
leds Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds 2014-01-28 18:53:01 -08:00
lguest
macintosh Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2014-01-27 21:11:26 -08:00
mailbox drivers/mailbox/omap: make mbox->irq signed for error handling 2014-01-23 16:36:53 -08:00
md dm space map metadata: fix refcount decrement below 0 which caused corruption 2014-03-07 12:02:47 -05:00
media [media] adv7842: Composite free-run platfrom-data fix 2014-02-04 06:46:10 -02:00
memory
memstick drivers/memstick/host/rtsx_pci_ms.c: fix ms card data transfer bug 2014-01-23 16:37:04 -08:00
message drivers/message/i2o/i2o_config.c: fix deadlock in compat_ioctl(I2OGETIOPS) 2014-02-10 16:01:40 -08:00
mfd sound fixes for 3.14-rc4 2014-02-21 09:55:32 -08:00
misc mei: set client's read_cb to NULL when flow control fails 2014-02-18 10:07:36 -08:00
mmc Fix uses of dma_max_pfn() when converting to a limiting address 2014-02-17 23:08:41 +00:00
mtd Just a single fix for the UBI module unload path which makes sure we do not 2014-02-27 10:36:50 -08:00
net USB fixes for 3.14-rc6 2014-03-09 18:59:14 -07:00
nfc
ntb
nubus
of Device tree compatible match order bug fix 2014-02-21 14:35:05 -08:00
oprofile
parisc
parport TTY/Serial driver patches for 3.14-rc1 2014-01-20 16:05:23 -08:00
pci PCI updates for v3.14: 2014-02-20 12:46:24 -08:00
pcmcia PCI changes for the v3.14 merge window: 2014-01-22 16:39:28 -08:00
phy phy: let phy_provider_register be the last step in registering PHY 2014-02-18 12:13:16 -08:00
pinctrl ARM: SoC fixes for 3.14-rc 2014-03-09 19:27:31 -07:00
platform platform/chrome: Cleanups and improvements 2014-01-29 20:06:01 -08:00
pnp
power Few fixes: 2014-02-14 10:32:28 -08:00
powercap
pps
ps3
ptp
pwm pwm: lp3943: Fix potential memory leak during request 2014-02-26 15:45:12 +01:00
rapidio rapidio/tsi721: fix tasklet termination in dma channel release 2014-03-04 07:55:49 -08:00
regulator regulator: Fixes for v3.14-rc5 2014-03-04 08:41:42 -08:00
remoteproc
reset
rpmsg
rtc drivers/rtc/rtc-s3c.c: fix incorrect way of save/restore of S3C2410_TICNT for TYPE_S3C64XX 2014-03-04 07:55:48 -08:00
s390 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-03-04 08:44:32 -08:00
sbus Sparc: sparc_cpu_model isn't in asm/system.h any more [ver #2] 2014-02-20 13:34:11 -05:00
scsi Merge git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2014-03-01 21:33:09 -06:00
sfi
sh
sn
spi Merge remote-tracking branches 'spi/fix/ath79', 'spi/fix/atmel', 'spi/fix/coldfire', 'spi/fix/fsl-dspi', 'spi/fix/imx' and 'spi/fix/topcliff-pch' into spi-linus 2014-03-07 11:08:13 +08:00
ssb Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2014-01-30 17:20:32 -08:00
staging staging/cxt1e1/linux.c: Correct arbitrary memory write in c4_ioctl() 2014-03-04 16:20:01 -08:00
target Target/sbc: Fix sbc_copy_prot for offset scatters 2014-03-06 20:52:11 -08:00
tc
thermal Thermal: thermal zone governor fix 2014-03-03 23:15:57 +08:00
tty Revert "tty: Set correct tty name in 'active' sysfs attribute" 2014-02-22 14:31:04 -08:00
uio
usb Revert "xhci 1.0: Limit arbitrarily-aligned scatter gather." 2014-03-07 11:48:13 -08:00
uwb
vfio mm: close PageTail race 2014-03-04 07:55:47 -08:00
vhost Merge git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2014-03-01 21:33:09 -06:00
video video: Kconfig: Allow more broad selection of the imxfb framebuffer driver. 2014-02-14 10:44:52 +02:00
virt
virtio A few simple fixes. Quiet cycle. 2014-01-22 22:24:35 -08:00
vlynq drivers/vlynq/vlynq.c: fix another resource size off by 1 error 2014-01-23 16:36:55 -08:00
vme VME: Correct read/write alignment algorithm 2014-02-07 08:16:14 -08:00
w1 drivers/w1/masters/w1-gpio.c: add strong pullup emulation 2014-01-23 16:37:04 -08:00
watchdog watchdog: w83697hf_wdt: return ENODEV if no device was found 2014-02-21 20:36:46 +01:00
xen Bug-fix: 2014-02-12 12:28:05 -08:00
zorro
Kconfig
Makefile