linux-toradex.git/drivers/gpio/gpiolib.c, branch v3.4.45 Linux kernel for Apalis and Colibri modules gpiolib: Don't return -EPROBE_DEFER to sysfs, or for invalid gpios 2012-11-05T08:50:41+00:00 Mathias Nyman mathias.nyman@linux.intel.com 2012-10-25T11:03:03+00:00 e7355f1112773a015e914b4f815460b7bbe88954 commit ad2fab36d7922401c4576fb7ea9b21a47a29a17f upstream. gpios requested with invalid numbers, or gpios requested from userspace via sysfs should not try to be deferred on failure. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit ad2fab36d7922401c4576fb7ea9b21a47a29a17f upstream.

gpios requested with invalid numbers, or gpios requested from userspace via sysfs
should not try to be deferred on failure.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gpiolib: Add comments explaining the _cansleep() WARN_ON()s 2012-03-05T15:05:08+00:00 Mark Brown broonie@opensource.wolfsonmicro.com 2012-02-17T18:46:00+00:00 e4e449e82871c53ef3b22bd3a50fceabc0638926 I've seen users getting very confused by the WARN_ON()s for can_sleep GPIOs in the atomic-safe paths, the discoverability of the non-atomic version of the API seems to be hampered by the fact that it's defined in a header file not the .c file where the warnings are. Add a couple of comments next to the warnings to help people on their way. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Reviwed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca> 
I've seen users getting very confused by the WARN_ON()s for can_sleep
GPIOs in the atomic-safe paths, the discoverability of the non-atomic
version of the API seems to be hampered by the fact that it's defined
in a header file not the .c file where the warnings are.

Add a couple of comments next to the warnings to help people on their
way.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Reviwed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
gpio: gpiolib: Support for open source/emitter gpios 2012-03-05T14:49:44+00:00 Laxman Dewangan ldewangan@nvidia.com 2012-02-17T14:56:22+00:00 25553ff0756c59b617af6bdd280c94e943164184 Adding support for the open source gpio on which client can specify the open source property through GPIO flag GPIOF_OPEN_SOURCE at the time of gpio request. The open source pins are normally pulled low and it cannot be driven to output with value of 0 and so when client request for setting the pin to LOW, the gpio will be set to input direction to make pin in tristate and hence PULL-DOWN on pins will make the state to LOW. The open source pin can be driven to HIGH by setting output with value of 1. Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com> Reviwed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Grant Likely <grant.likely@secretlab.ca> 
Adding support for the open source gpio on which client
can specify the open source property through GPIO flag
GPIOF_OPEN_SOURCE at the time of gpio request.
The open source pins are normally pulled low and it
cannot be driven to output with value of 0 and so
when client request for setting the pin to LOW, the
gpio will be set to input direction to make pin in tristate
and hence PULL-DOWN on pins will make the state to LOW.
The open source pin can be driven to HIGH by setting output
with value of 1.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviwed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
gpio: gpiolib: Support for open drain/collector gpios 2012-03-05T14:49:44+00:00 Laxman Dewangan ldewangan@nvidia.com 2012-02-17T14:56:21+00:00 aca5ce14eb773a75e5d935968b2e390dc5bd29c3 Adding support for the open drain gpio on which client can specify the open drain property through GPIO flag GPIOF_OPEN_DRAIN at the time of gpio request. The open drain pins are normally pulled high and it cannot be driven to output with value of 1 and so when client request for setting the pin to HIGH, the gpio will be set to input direction to make pin in tristate and hence PULL-UP on pins will make the state to HIGH. The open drain pin can be driven to LOW by setting output with value of 0. Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com> Reviwed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Grant Likely <grant.likely@secretlab.ca> 
Adding support for the open drain gpio on which client
can specify the open drain property through GPIO flag
GPIOF_OPEN_DRAIN at the time of gpio request.
The open drain pins are normally pulled high and it
cannot be driven to output with value of 1 and so
when client request for setting the pin to HIGH, the
gpio will be set to input direction to make pin in tristate
and hence PULL-UP on pins will make the state to HIGH.
The open drain pin can be driven to LOW by setting output
with value of 0.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviwed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
gpio: constify the data parameter to gpiochip_find() 2012-03-02T22:56:03+00:00 Grant Likely grant.likely@secretlab.ca 2012-03-02T22:56:03+00:00 6e2cf6514066cdd5a0844b34760029a5a4870318 Signed-off-by: Grant Likely <grant.likely@secretlab.ca> 
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Fix circular locking dependency (3.3-rc2) 2012-02-15T20:06:07+00:00 Ming Lei tom.leiming@gmail.com 2012-02-13T14:53:20+00:00 864533ceb6db336dead389577c102a8b792a121a Hi, On Wed, Feb 8, 2012 at 8:41 PM, Felipe Balbi <balbi@ti.com> wrote: > Hi guys, > > I have just triggered the folllowing: > > [   84.860321] ====================================================== > [   84.860321] [ INFO: possible circular locking dependency detected ] > [   84.860321] 3.3.0-rc2-00026-ge4e8a39 #474 Not tainted > [   84.860321] ------------------------------------------------------- > [   84.860321] bash/949 is trying to acquire lock: > [   84.860321]  (sysfs_lock){+.+.+.}, at: [<c0275358>] gpio_value_store+0x24/0xcc > [   84.860321] > [   84.860321] but task is already holding lock: > [   84.860321]  (s_active#22){++++.+}, at: [<c016996c>] sysfs_write_file+0xdc/0x184 > [   84.911468] > [   84.911468] which lock already depends on the new lock. > [   84.911468] > [   84.920043] > [   84.920043] the existing dependency chain (in reverse order) is: > [   84.920043] > [   84.927886] -> #1 (s_active#22){++++.+}: > [   84.927886]        [<c008f640>] check_prevs_add+0xdc/0x150 > [   84.927886]        [<c008fc18>] validate_chain.clone.24+0x564/0x694 > [   84.927886]        [<c0090cdc>] __lock_acquire+0x49c/0x980 > [   84.951660]        [<c0091838>] lock_acquire+0x98/0x100 > [   84.951660]        [<c016a8e8>] sysfs_deactivate+0xb0/0x100 > [   84.962982]        [<c016b1b4>] sysfs_addrm_finish+0x2c/0x6c > [   84.962982]        [<c016b8bc>] sysfs_remove_dir+0x84/0x98 > [   84.962982]        [<c02590d8>] kobject_del+0x10/0x78 > [   84.974670]        [<c02c29e8>] device_del+0x140/0x170 > [   84.974670]        [<c02c2a24>] device_unregister+0xc/0x18 > [   84.985382]        [<c0276894>] gpio_unexport+0xbc/0xdc > [   84.985382]        [<c02768c8>] gpio_free+0x14/0xfc > [   85.001708]        [<c0276a28>] unexport_store+0x78/0x8c > [   85.001708]        [<c02c5af8>] class_attr_store+0x18/0x24 > [   85.007293]        [<c0169990>] sysfs_write_file+0x100/0x184 > [   85.018981]        [<c0109d48>] vfs_write+0xb4/0x148 > [   85.018981]        [<c0109fd0>] sys_write+0x40/0x70 > [   85.018981]        [<c0013cc0>] ret_fast_syscall+0x0/0x3c > [   85.035003] > [   85.035003] -> #0 (sysfs_lock){+.+.+.}: > [   85.035003]        [<c008f54c>] check_prev_add+0x680/0x698 > [   85.035003]        [<c008f640>] check_prevs_add+0xdc/0x150 > [   85.052093]        [<c008fc18>] validate_chain.clone.24+0x564/0x694 > [   85.052093]        [<c0090cdc>] __lock_acquire+0x49c/0x980 > [   85.052093]        [<c0091838>] lock_acquire+0x98/0x100 > [   85.069885]        [<c047e280>] mutex_lock_nested+0x3c/0x2f4 > [   85.069885]        [<c0275358>] gpio_value_store+0x24/0xcc > [   85.069885]        [<c02c18dc>] dev_attr_store+0x18/0x24 > [   85.087158]        [<c0169990>] sysfs_write_file+0x100/0x184 > [   85.087158]        [<c0109d48>] vfs_write+0xb4/0x148 > [   85.098297]        [<c0109fd0>] sys_write+0x40/0x70 > [   85.098297]        [<c0013cc0>] ret_fast_syscall+0x0/0x3c > [   85.109069] > [   85.109069] other info that might help us debug this: > [   85.109069] > [   85.117462]  Possible unsafe locking scenario: > [   85.117462] > [   85.117462]        CPU0                    CPU1 > [   85.128417]        ----                    ---- > [   85.128417]   lock(s_active#22); > [   85.128417]                                lock(sysfs_lock); > [   85.128417]                                lock(s_active#22); > [   85.142486]   lock(sysfs_lock); > [   85.151794] > [   85.151794]  *** DEADLOCK *** > [   85.151794] > [   85.151794] 2 locks held by bash/949: > [   85.158020]  #0:  (&buffer->mutex){+.+.+.}, at: [<c01698b8>] sysfs_write_file+0x28/0x184 > [   85.170349]  #1:  (s_active#22){++++.+}, at: [<c016996c>] sysfs_write_file+0xdc/0x184 > [   85.170349] > [   85.178588] stack backtrace: > [   85.178588] [<c001b824>] (unwind_backtrace+0x0/0xf0) from [<c008de64>] (print_circular_bug+0x100/0x114) > [   85.193023] [<c008de64>] (print_circular_bug+0x100/0x114) from [<c008f54c>] (check_prev_add+0x680/0x698) > [   85.193023] [<c008f54c>] (check_prev_add+0x680/0x698) from [<c008f640>] (check_prevs_add+0xdc/0x150) > [   85.212524] [<c008f640>] (check_prevs_add+0xdc/0x150) from [<c008fc18>] (validate_chain.clone.24+0x564/0x694) > [   85.212524] [<c008fc18>] (validate_chain.clone.24+0x564/0x694) from [<c0090cdc>] (__lock_acquire+0x49c/0x980) > [   85.233306] [<c0090cdc>] (__lock_acquire+0x49c/0x980) from [<c0091838>] (lock_acquire+0x98/0x100) > [   85.233306] [<c0091838>] (lock_acquire+0x98/0x100) from [<c047e280>] (mutex_lock_nested+0x3c/0x2f4) > [   85.242614] [<c047e280>] (mutex_lock_nested+0x3c/0x2f4) from [<c0275358>] (gpio_value_store+0x24/0xcc) > [   85.261840] [<c0275358>] (gpio_value_store+0x24/0xcc) from [<c02c18dc>] (dev_attr_store+0x18/0x24) > [   85.261840] [<c02c18dc>] (dev_attr_store+0x18/0x24) from [<c0169990>] (sysfs_write_file+0x100/0x184) > [   85.271240] [<c0169990>] (sysfs_write_file+0x100/0x184) from [<c0109d48>] (vfs_write+0xb4/0x148) > [   85.290008] [<c0109d48>] (vfs_write+0xb4/0x148) from [<c0109fd0>] (sys_write+0x40/0x70) > [   85.298400] [<c0109fd0>] (sys_write+0x40/0x70) from [<c0013cc0>] (ret_fast_syscall+0x0/0x3c) > -bash: echo: write error: Operation not permitted > > the way to trigger is: > > root@legolas:~# cd /sys/class/gpio/ > root@legolas:/sys/class/gpio# echo 2 > export > root@legolas:/sys/class/gpio# echo 2 > unexport > root@legolas:/sys/class/gpio# echo 2 > export > root@legolas:/sys/class/gpio# cd gpio2/ > root@legolas:/sys/class/gpio/gpio2# echo 1 > value Looks 'sysfs_lock' needn't to be held for unregister, so the patch below may fix the problem. Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Grant Likely <grant.likely@secretlab.ca> 
Hi,

On Wed, Feb 8, 2012 at 8:41 PM, Felipe Balbi <balbi@ti.com> wrote:
> Hi guys,
>
> I have just triggered the folllowing:
>
> [   84.860321] ======================================================
> [   84.860321] [ INFO: possible circular locking dependency detected ]
> [   84.860321] 3.3.0-rc2-00026-ge4e8a39 #474 Not tainted
> [   84.860321] -------------------------------------------------------
> [   84.860321] bash/949 is trying to acquire lock:
> [   84.860321]  (sysfs_lock){+.+.+.}, at: [<c0275358>] gpio_value_store+0x24/0xcc
> [   84.860321]
> [   84.860321] but task is already holding lock:
> [   84.860321]  (s_active#22){++++.+}, at: [<c016996c>] sysfs_write_file+0xdc/0x184
> [   84.911468]
> [   84.911468] which lock already depends on the new lock.
> [   84.911468]
> [   84.920043]
> [   84.920043] the existing dependency chain (in reverse order) is:
> [   84.920043]
> [   84.927886] -> #1 (s_active#22){++++.+}:
> [   84.927886]        [<c008f640>] check_prevs_add+0xdc/0x150
> [   84.927886]        [<c008fc18>] validate_chain.clone.24+0x564/0x694
> [   84.927886]        [<c0090cdc>] __lock_acquire+0x49c/0x980
> [   84.951660]        [<c0091838>] lock_acquire+0x98/0x100
> [   84.951660]        [<c016a8e8>] sysfs_deactivate+0xb0/0x100
> [   84.962982]        [<c016b1b4>] sysfs_addrm_finish+0x2c/0x6c
> [   84.962982]        [<c016b8bc>] sysfs_remove_dir+0x84/0x98
> [   84.962982]        [<c02590d8>] kobject_del+0x10/0x78
> [   84.974670]        [<c02c29e8>] device_del+0x140/0x170
> [   84.974670]        [<c02c2a24>] device_unregister+0xc/0x18
> [   84.985382]        [<c0276894>] gpio_unexport+0xbc/0xdc
> [   84.985382]        [<c02768c8>] gpio_free+0x14/0xfc
> [   85.001708]        [<c0276a28>] unexport_store+0x78/0x8c
> [   85.001708]        [<c02c5af8>] class_attr_store+0x18/0x24
> [   85.007293]        [<c0169990>] sysfs_write_file+0x100/0x184
> [   85.018981]        [<c0109d48>] vfs_write+0xb4/0x148
> [   85.018981]        [<c0109fd0>] sys_write+0x40/0x70
> [   85.018981]        [<c0013cc0>] ret_fast_syscall+0x0/0x3c
> [   85.035003]
> [   85.035003] -> #0 (sysfs_lock){+.+.+.}:
> [   85.035003]        [<c008f54c>] check_prev_add+0x680/0x698
> [   85.035003]        [<c008f640>] check_prevs_add+0xdc/0x150
> [   85.052093]        [<c008fc18>] validate_chain.clone.24+0x564/0x694
> [   85.052093]        [<c0090cdc>] __lock_acquire+0x49c/0x980
> [   85.052093]        [<c0091838>] lock_acquire+0x98/0x100
> [   85.069885]        [<c047e280>] mutex_lock_nested+0x3c/0x2f4
> [   85.069885]        [<c0275358>] gpio_value_store+0x24/0xcc
> [   85.069885]        [<c02c18dc>] dev_attr_store+0x18/0x24
> [   85.087158]        [<c0169990>] sysfs_write_file+0x100/0x184
> [   85.087158]        [<c0109d48>] vfs_write+0xb4/0x148
> [   85.098297]        [<c0109fd0>] sys_write+0x40/0x70
> [   85.098297]        [<c0013cc0>] ret_fast_syscall+0x0/0x3c
> [   85.109069]
> [   85.109069] other info that might help us debug this:
> [   85.109069]
> [   85.117462]  Possible unsafe locking scenario:
> [   85.117462]
> [   85.117462]        CPU0                    CPU1
> [   85.128417]        ----                    ----
> [   85.128417]   lock(s_active#22);
> [   85.128417]                                lock(sysfs_lock);
> [   85.128417]                                lock(s_active#22);
> [   85.142486]   lock(sysfs_lock);
> [   85.151794]
> [   85.151794]  *** DEADLOCK ***
> [   85.151794]
> [   85.151794] 2 locks held by bash/949:
> [   85.158020]  #0:  (&buffer->mutex){+.+.+.}, at: [<c01698b8>] sysfs_write_file+0x28/0x184
> [   85.170349]  #1:  (s_active#22){++++.+}, at: [<c016996c>] sysfs_write_file+0xdc/0x184
> [   85.170349]
> [   85.178588] stack backtrace:
> [   85.178588] [<c001b824>] (unwind_backtrace+0x0/0xf0) from [<c008de64>] (print_circular_bug+0x100/0x114)
> [   85.193023] [<c008de64>] (print_circular_bug+0x100/0x114) from [<c008f54c>] (check_prev_add+0x680/0x698)
> [   85.193023] [<c008f54c>] (check_prev_add+0x680/0x698) from [<c008f640>] (check_prevs_add+0xdc/0x150)
> [   85.212524] [<c008f640>] (check_prevs_add+0xdc/0x150) from [<c008fc18>] (validate_chain.clone.24+0x564/0x694)
> [   85.212524] [<c008fc18>] (validate_chain.clone.24+0x564/0x694) from [<c0090cdc>] (__lock_acquire+0x49c/0x980)
> [   85.233306] [<c0090cdc>] (__lock_acquire+0x49c/0x980) from [<c0091838>] (lock_acquire+0x98/0x100)
> [   85.233306] [<c0091838>] (lock_acquire+0x98/0x100) from [<c047e280>] (mutex_lock_nested+0x3c/0x2f4)
> [   85.242614] [<c047e280>] (mutex_lock_nested+0x3c/0x2f4) from [<c0275358>] (gpio_value_store+0x24/0xcc)
> [   85.261840] [<c0275358>] (gpio_value_store+0x24/0xcc) from [<c02c18dc>] (dev_attr_store+0x18/0x24)
> [   85.261840] [<c02c18dc>] (dev_attr_store+0x18/0x24) from [<c0169990>] (sysfs_write_file+0x100/0x184)
> [   85.271240] [<c0169990>] (sysfs_write_file+0x100/0x184) from [<c0109d48>] (vfs_write+0xb4/0x148)
> [   85.290008] [<c0109d48>] (vfs_write+0xb4/0x148) from [<c0109fd0>] (sys_write+0x40/0x70)
> [   85.298400] [<c0109fd0>] (sys_write+0x40/0x70) from [<c0013cc0>] (ret_fast_syscall+0x0/0x3c)
> -bash: echo: write error: Operation not permitted
>
> the way to trigger is:
>
> root@legolas:~# cd /sys/class/gpio/
> root@legolas:/sys/class/gpio# echo 2 > export
> root@legolas:/sys/class/gpio# echo 2 > unexport
> root@legolas:/sys/class/gpio# echo 2 > export
> root@legolas:/sys/class/gpio# cd gpio2/
> root@legolas:/sys/class/gpio/gpio2# echo 1 > value

Looks 'sysfs_lock' needn't to be held for unregister, so the patch below may
fix the problem.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
gpio/powerpc: Eliminate duplication of of_get_named_gpio_flags() 2011-12-12T20:40:16+00:00 Grant Likely grant.likely@secretlab.ca 2011-12-12T16:25:57+00:00 1a2d397a6eb5cf40c382d9e3d4bc04aaeb025336 A large chunk of qe_pin_request() is unnecessarily cut-and-paste directly from of_get_named_gpio_flags(). This patch cuts out the duplicate code and replaces it with a call to of_get_gpio(). v2: fixed compile error due to missing gpio_to_chip() Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Kumar Gala <galak@kernel.crashing.org> 
A large chunk of qe_pin_request() is unnecessarily cut-and-paste
directly from of_get_named_gpio_flags().  This patch cuts out the
duplicate code and replaces it with a call to of_get_gpio().

v2: fixed compile error due to missing gpio_to_chip()

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Kumar Gala <galak@kernel.crashing.org>
gpiolib: output basic details and consolidate gpio device drivers 2011-12-12T20:40:16+00:00 Grant Likely grant.likely@secretlab.ca 2011-11-06T18:36:18+00:00 64842aad5ec5ea3b6f6e716ce53a863f7c409da8 This patch adds a kernel message, containing GPIO range and device name on successful device registration, and removes duplicate messages from the following drivers: * gpio-adp5588 * gpio-bt8xx * gpio-cs5535 * gpio-janz-ttl * gpio-nomadik * gpio-pcf857x * gpio-xilinx * drivers/of/gpio.c Signed-off-by: Hartmut Knaack <knaack.h@gmx.de> [grant.likely@secretlab.ca: squashed 2 patches together] Signed-off-by: Grant Likely <grant.likely@secretlab.ca> 
This patch adds a kernel message, containing GPIO range and device
name on successful device registration, and removes duplicate messages from the following drivers:
	* gpio-adp5588
	* gpio-bt8xx
	* gpio-cs5535
	* gpio-janz-ttl
	* gpio-nomadik
	* gpio-pcf857x
	* gpio-xilinx
	* drivers/of/gpio.c

Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
[grant.likely@secretlab.ca: squashed 2 patches together]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
gpio: make gpio_{request,free}_array gpio array parameter const 2011-05-27T23:56:45+00:00 Lars-Peter Clausen lars@metafoo.de 2011-05-25T23:20:31+00:00 7c295975a85b049385dfe0d5ee0d4d543619fbdc gpio_{request,free}_array should not (and do not) modify the passed gpio array, so make the parameter const. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Eric Miao <eric.y.miao@gmail.com> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Grant Likely <grant.likely@secretlab.ca> 
gpio_{request,free}_array should not (and do not) modify the passed gpio
array, so make the parameter const.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Eric Miao <eric.y.miao@gmail.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
gpio: add trace events for setting direction and value 2011-05-20T06:40:19+00:00 Uwe Kleine-König u.kleine-koenig@pengutronix.de 2011-05-20T06:40:19+00:00 3f397c2144e46d9127662fdb6314f21960d8563d This patch allows to trace gpio operations using ftrace Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Grant Likely <grant.likely@secretlab.ca> 
This patch allows to trace gpio operations using ftrace

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>