Commit Graph

86 Commits

Author SHA1 Message Date
Vladimir Zapolskiy 60befd2ea1 gpio: update gpiochip .get() callback description
Since gpiochip .get() callback may return a negative error value, it
strictly limits the range of possible non-error returned values to
a subset of [30:0] bitmask, however on practice on success all
gpiochip drivers return either 0 for low signal or 1 for high signal,
this is assured by "gpio: *: Be sure to clamp return value" series of
changes. To avoid any confusion, misinterpretation and potential
errors while developing gpiochip drivers in future convert this
implicit assumption to a mandatory rule.

For output signals with unknown output signal state gpiochip drivers
should return a negative error instead of 0.

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-12-26 22:28:43 +01:00
Linus Walleij 58383c7842 gpio: change member .dev to .parent
The name .dev in a struct is normally reserved for a struct device
that is let us say a superclass to the thing described by the struct.
struct gpio_chip stands out by confusingly using a struct device *dev
to point to the parent device (such as a platform_device) that
represents the hardware. As we want to give gpio_chip:s real devices,
this is not working. We need to rename this member to parent.

This was done by two coccinelle scripts, I guess it is possible to
combine them into one, but I don't know such stuff. They look like
this:

@@
struct gpio_chip *var;
@@
-var->dev
+var->parent

and:

@@
struct gpio_chip var;
@@
-var.dev
+var.parent

and:

@@
struct bgpio_chip *var;
@@
-var->gc.dev
+var->gc.parent

Plus a few instances of bgpio that I couldn't figure out how
to teach Coccinelle to rewrite.

This patch hits all over the place, but I *strongly* prefer this
solution to any piecemal approaches that just exercise patch
mechanics all over the place. It mainly hits drivers/gpio and
drivers/pinctrl which is my own backyard anyway.

Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Rafał Miłecki <zajec5@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Cc: Alek Du <alek.du@intel.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-11-19 09:24:35 +01:00
Jonas Gorski c771c2f484 gpiolib: provide generic request/free implementations
Provide generic request/free implementations that pinctrl aware gpio
drivers can use instead of open coding if they use a 1:1 pin to gpio
signal mapping.

Signed-off-by: Jonas Gorski <jogo@openwrt.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-10-16 22:11:16 +02:00
Grygorii Strashko 41d6bb4c89 gpiolib: add description for gpio irqchip fields in struct gpio_chip
Add missed description for GPIO irqchip fields in struct gpio_chip.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-08-26 09:29:50 +02:00
Grygorii Strashko a0a8bcf467 gpiolib: irqchip: use different lockdep class for each gpio irqchip
Since IRQ chip helpers were introduced drivers lose ability to
register separate lockdep classes for each registered GPIO IRQ
chip and the gpiolib now is using shared lockdep class for
all GPIO IRQ chips (gpiochip_irq_lock_class).
As result, lockdep will produce warning when there are min two
stacked GPIO chips and all of them are interrupt controllers.

HW configuration which generates lockdep warning (TI dra7-evm):

[SOC GPIO bankA.gpioX]
  <- irq - [pcf875x.gpioY]
            <- irq - DevZ.enable_irq_wake(pcf_gpioY_irq);
The issue was reported in [1] and discussed [2].

=============================================
[ INFO: possible recursive locking detected ]
4.2.0-rc6-00013-g5d050ed-dirty #55 Not tainted
---------------------------------------------
sh/63 is trying to acquire lock:
 (class){......}, at: [<c009b91c>] __irq_get_desc_lock+0x50/0x94

but task is already holding lock:
 (class){......}, at: [<c009b91c>] __irq_get_desc_lock+0x50/0x94

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(class);
  lock(class);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

7 locks held by sh/63:
 #0:  (sb_writers#4){.+.+.+}, at: [<c016bbb8>] vfs_write+0x13c/0x164
 #1:  (&of->mutex){+.+.+.}, at: [<c01debf4>] kernfs_fop_write+0x4c/0x1a0
 #2:  (s_active#36){.+.+.+}, at: [<c01debfc>] kernfs_fop_write+0x54/0x1a0
 #3:  (pm_mutex){+.+.+.}, at: [<c009758c>] pm_suspend+0xec/0x4c4
 #4:  (&dev->mutex){......}, at: [<c03f77f8>] __device_suspend+0xd4/0x398
 #5:  (&gpio->lock){+.+.+.}, at: [<c009b940>] __irq_get_desc_lock+0x74/0x94
 #6:  (class){......}, at: [<c009b91c>] __irq_get_desc_lock+0x50/0x94

stack backtrace:
CPU: 0 PID: 63 Comm: sh Not tainted 4.2.0-rc6-00013-g5d050ed-dirty #55
Hardware name: Generic DRA74X (Flattened Device Tree)
[<c0016e24>] (unwind_backtrace) from [<c0013338>] (show_stack+0x10/0x14)
[<c0013338>] (show_stack) from [<c05f6b24>] (dump_stack+0x84/0x9c)
[<c05f6b24>] (dump_stack) from [<c00903f4>] (__lock_acquire+0x19c0/0x1e20)
[<c00903f4>] (__lock_acquire) from [<c0091098>] (lock_acquire+0xa8/0x128)
[<c0091098>] (lock_acquire) from [<c05fd61c>] (_raw_spin_lock_irqsave+0x38/0x4c)
[<c05fd61c>] (_raw_spin_lock_irqsave) from [<c009b91c>] (__irq_get_desc_lock+0x50/0x94)
[<c009b91c>] (__irq_get_desc_lock) from [<c009c4f4>] (irq_set_irq_wake+0x20/0xfc)
[<c009c4f4>] (irq_set_irq_wake) from [<c0393ac4>] (pcf857x_irq_set_wake+0x24/0x54)
[<c0393ac4>] (pcf857x_irq_set_wake) from [<c009c560>] (irq_set_irq_wake+0x8c/0xfc)
[<c009c560>] (irq_set_irq_wake) from [<c04a02ac>] (gpio_keys_suspend+0x70/0xd4)
[<c04a02ac>] (gpio_keys_suspend) from [<c03f6a00>] (dpm_run_callback+0x50/0x124)
[<c03f6a00>] (dpm_run_callback) from [<c03f7830>] (__device_suspend+0x10c/0x398)
[<c03f7830>] (__device_suspend) from [<c03f90f0>] (dpm_suspend+0x134/0x2f4)
[<c03f90f0>] (dpm_suspend) from [<c0096e20>] (suspend_devices_and_enter+0xa8/0x728)
[<c0096e20>] (suspend_devices_and_enter) from [<c00977cc>] (pm_suspend+0x32c/0x4c4)
[<c00977cc>] (pm_suspend) from [<c0096060>] (state_store+0x64/0xb8)
[<c0096060>] (state_store) from [<c01dec64>] (kernfs_fop_write+0xbc/0x1a0)
[<c01dec64>] (kernfs_fop_write) from [<c016b280>] (__vfs_write+0x20/0xd8)
[<c016b280>] (__vfs_write) from [<c016bb0c>] (vfs_write+0x90/0x164)
[<c016bb0c>] (vfs_write) from [<c016c330>] (SyS_write+0x44/0x9c)
[<c016c330>] (SyS_write) from [<c000f500>] (ret_fast_syscall+0x0/0x54)

Lets fix it by using separate lockdep class for each registered GPIO
IRQ Chip. This is done by wrapping gpiochip_irqchip_add call into macros.

The implementation of this patch inspired by solution done by Nicolas
Boichat for regmap [3]

[1] http://www.spinics.net/lists/linux-gpio/msg05844.html
[2] http://www.spinics.net/lists/linux-gpio/msg06021.html
[3] http://www.spinics.net/lists/arm-kernel/msg429834.html

Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roger Quadros <rogerq@ti.com>
Reported-by: Roger Quadros <rogerq@ti.com>
Tested-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-08-17 15:32:03 +02:00
Geert Uytterhoeven 30bb6fb39e gpio: Remove double "base" in comment
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-07-16 00:12:24 +02:00
Linus Walleij af6c235d1a gpio: discourage passing base to gpio_chip
Passing a fixed base in struct gpio_chip is done for legacy
systems that cannot handle dynamic allocation. Discourage this
behaviour in the kerneldoc.

Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-14 12:19:48 +02:00
Dmitry Eremin-Solenikov 25e4fe92a2 gpiolib: cleanup chained handler and data
Clean up chained handler and handler data if they were set by
gpiochip_set_chained_irqchip().

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-13 13:02:36 +02:00
Johan Hovold 6a4b6b0a3b gpio: sysfs: clean up chip class-device handling
Clean gpio-chip class device registration and deregistration.

The class device is registered when a gpio-chip is added (or from
gpiolib_sysfs_init post-core init call), and deregistered when the chip
is removed.

Store the class device in struct gpio_chip directly rather than do a
class-device lookup on deregistration. This also removes the need for
the exported flag.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:46:44 +02:00
Linus Walleij 964cb34188 gpio: move pincontrol calls to <linux/gpio/driver.h>
These functions do not belong in <asm-generic/gpio.h> since the
split into separate GPIO headers under <linux/gpio/*>. Move them
to <linux/gpio/driver.h> as is apropriate.

Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-03-19 09:45:54 +01:00
Rojhalat Ibrahim 5f42424354 gpiolib: allow simultaneous setting of multiple GPIO outputs
Introduce new functions gpiod_set_array & gpiod_set_raw_array to the consumer
interface which allow setting multiple outputs with just one function call.
Also add an optional set_multiple function to the driver interface. Without an
implementation of that function in the chip driver outputs are set
sequentially.

Implementing the set_multiple function in a chip driver allows for:
- Improved performance for certain use cases. The original motivation for this
  was the task of configuring an FPGA. In that specific case, where 9 GPIO
  lines have to be set many times, configuration time goes down from 48 s to
  20 s when using the new function.
- Simultaneous glitch-free setting of multiple pins on any kind of parallel
  bus attached to GPIOs provided they all reside on the same chip and bank.

Limitations:
  Performance is only improved for normal high-low outputs. Open drain and
  open source outputs are always set separately from each other. Those kinds
  of outputs could probably be accelerated in a similar way if we could
  forgo the error checking when setting GPIO directions.

Change log:
  v6: - rebase on current linux-gpio devel branch
  v5: - check can_sleep property per chip
      - remove superfluous checks
      - supplement documentation
  v4: - add gpiod_set_array function for setting logical values
      - change interface of the set_multiple driver function to use
        unsigned long as type for the bit fields
      - use generic bitops (which also use unsigned long for bit fields)
      - do not use ARCH_NR_GPIOS any more
  v3: - add documentation
      - change commit message
  v2: - use descriptor interface
      - allow arbitrary groups of GPIOs spanning multiple chips

Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-11-27 15:01:18 +01:00
Alexandre Courbot e3a2e87893 gpio: rename gpio_lock_as_irq to gpiochip_lock_as_irq
This function actually operates on a gpio_chip, so its prefix should
reflect that fact for consistency with other functions defined in
gpio/driver.h.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-10-28 17:30:59 +01:00
Linus Torvalds ea584595fc This is the bulk of GPIO changes for the v3.18 development
cycle:
 
 - Increase the default ARCH_NR_GPIO from 256 to 512. This
   was done to avoid having a custom <asm/gpio.h> header for
   the x86 architecture - GPIO is custom and complicated
   enough as it is already! We want to move to a radix to
   store the descriptors going forward, and finally get rid
   of this fixed array size altogether.
 
 - Endgame patching of the gpio_remove() semantics initiated
   by Abdoulaye Berthe. It is not accepted by the system that
   the removal of a GPIO chip fails during e.g. reboot or
   shutdown, and therefore the return value has now painfully
   been refactored away. For special cases like GPIO expanders
   on a hot-pluggable bus like USB, we may later add some
   gpiochip_try_remove() call, but for the cases we have now,
   return values are moot.
 
 - Some incremental refactoring of the gpiolib core and ACPI
   GPIO library for more descriptor usage.
 
 - Refactor the chained IRQ handler set-up method to handle
   also threaded, nested interrupts and set up the parent IRQ
   correctly. Switch STMPE and TC3589x drivers to use this
   registration method.
 
 - Add a .irq_not_threaded flag to the struct gpio_chip, so
   that also GPIO expanders that block but are still not
   using threaded IRQ handlers.
 
 - New drivers for the ARM64 X-Gene SoC GPIO controller.
 
 - The syscon GPIO driver has been improved to handle the
   "DSP GPIO" found on the TI Keystone 2 SoC:s.
 
 - ADNP driver switched to use gpiolib irqchip helpers.
 
 - Refactor the DWAPB driver to support being instantiated
   from and MFD cell (platform device).
 
 - Incremental feature improvement in the Zynq, MCP23S08,
   DWAPB, OMAP, Xilinx and Crystalcove drivers.
 
 - Various minor fixes.
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Merge tag 'gpio-v3.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO changes from Linus Walleij:
 "This is the bulk of GPIO changes for the v3.18 development cycle:

   - Increase the default ARCH_NR_GPIO from 256 to 512.  This was done
     to avoid having a custom <asm/gpio.h> header for the x86
     architecture - GPIO is custom and complicated enough as it is
     already! We want to move to a radix to store the descriptors going
     forward, and finally get rid of this fixed array size altogether.

   - Endgame patching of the gpio_remove() semantics initiated by
     Abdoulaye Berthe.  It is not accepted by the system that the
     removal of a GPIO chip fails during eg reboot or shutdown, and
     therefore the return value has now painfully been refactored away.
     For special cases like GPIO expanders on a hot-pluggable bus like
     USB, we may later add some gpiochip_try_remove() call, but for the
     cases we have now, return values are moot.

   - Some incremental refactoring of the gpiolib core and ACPI GPIO
     library for more descriptor usage.

   - Refactor the chained IRQ handler set-up method to handle also
     threaded, nested interrupts and set up the parent IRQ correctly.
     Switch STMPE and TC3589x drivers to use this registration method.

   - Add a .irq_not_threaded flag to the struct gpio_chip, so that also
     GPIO expanders that block but are still not using threaded IRQ
     handlers.

   - New drivers for the ARM64 X-Gene SoC GPIO controller.

   - The syscon GPIO driver has been improved to handle the "DSP GPIO"
     found on the TI Keystone 2 SoC:s.

   - ADNP driver switched to use gpiolib irqchip helpers.

   - Refactor the DWAPB driver to support being instantiated from and
     MFD cell (platform device).

   - Incremental feature improvement in the Zynq, MCP23S08, DWAPB, OMAP,
     Xilinx and Crystalcove drivers.

   - Various minor fixes"

* tag 'gpio-v3.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (52 commits)
  gpio: pch: Build context save/restore only for PM
  pinctrl: abx500: get rid of unused variable
  gpio: ks8695: fix 'else should follow close brace '}''
  gpio: stmpe: add verbose debug code
  gpio: stmpe: fix up interrupt enable logic
  gpio: staticize xway_stp_init()
  gpio: handle also nested irqchips in the chained handler set-up
  gpio: set parent irq on chained handlers
  gpiolib: irqchip: use irq_find_mapping while removing irqchip
  gpio: crystalcove: support virtual GPIO
  pinctrl: bcm281xx: make Kconfig dependency more strict
  gpio: kona: enable only on BCM_MOBILE or for compile testing
  gpio, bcm-kona, LLVMLinux: Remove use of __initconst
  gpio: Fix ngpio in gpio-xilinx driver
  gpio: dwapb: fix pointer to integer cast
  gpio: xgene: Remove unneeded #ifdef CONFIG_OF guard
  gpio: xgene: Remove unneeded forward declation for struct xgene_gpio
  gpio: xgene: Fix missing spin_lock_init()
  gpio: ks8695: fix switch case indentation
  gpiolib: add irq_not_threaded flag to gpio_chip
  ...
2014-10-09 14:58:15 -04:00
Linus Torvalds 28596c9722 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull "trivial tree" updates from Jiri Kosina:
 "Usual pile from trivial tree everyone is so eagerly waiting for"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  Remove MN10300_PROC_MN2WS0038
  mei: fix comments
  treewide: Fix typos in Kconfig
  kprobes: update jprobe_example.c for do_fork() change
  Documentation: change "&" to "and" in Documentation/applying-patches.txt
  Documentation: remove obsolete pcmcia-cs from Changes
  Documentation: update links in Changes
  Documentation: Docbook: Fix generated DocBook/kernel-api.xml
  score: Remove GENERIC_HAS_IOMAP
  gpio: fix 'CONFIG_GPIO_IRQCHIP' comments
  tty: doc: Fix grammar in serial/tty
  dma-debug: modify check_for_stack output
  treewide: fix errors in printk
  genirq: fix reference in devm_request_threaded_irq comment
  treewide: fix synchronize_rcu() in comments
  checkstack.pl: port to AArch64
  doc: queue-sysfs: minor fixes
  init/do_mounts: better syntax description
  MIPS: fix comment spelling
  powerpc/simpleboot: fix comment
  ...
2014-10-07 21:16:26 -04:00
Octavian Purdila 295494af06 gpiolib: add irq_not_threaded flag to gpio_chip
Some GPIO chips (e.g. the DLN2 USB adapter) have blocking get/set
operation but do not need a threaded irq handler.

Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-09-24 10:53:42 +02:00
abdoulaye berthe e1db1706c8 gpio: gpiolib: set gpiochip_remove retval to void
This avoids handling gpiochip remove error in device
remove handler.

Signed-off-by: Abdoulaye Berthe <berthe.ab@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-09-23 17:51:36 +02:00
Paul Bolle 7d75a87188 gpio: fix 'CONFIG_GPIO_IRQCHIP' comments
These two typos were introduced in commit 1425052097 ("gpio: add IRQ
chip helpers in gpiolib").

The correct symbol name is CONFIG_GPIOLIB_IRQCHIP.

[jkosina@suse.cz: add changelog]
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-09-05 13:54:41 +02:00
Alexandre Courbot abdc08a3a2 gpio: change gpiochip_request_own_desc() prototype
The current prototype of gpiochip_request_own_desc() requires to obtain
a pointer to a descriptor. This is in contradiction to all other GPIO
request schemes, and imposes an extra step of obtaining a descriptor to
drivers. Most drivers actually cannot even perform that step since the
function that does it (gpichip_get_desc()) is gpiolib-private.

Change gpiochip_request_own_desc() to return a descriptor from a
(chip, hwnum) tuple and update users of this function (currently
gpiolib-acpi only).

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-08-29 08:58:34 +02:00
Linus Walleij 0a6d315827 gpio: split gpiod board registration into machine header
As per example from the regulator subsystem: put all defines and
functions related to registering board info for GPIO descriptors
into a separate <linux/gpio/machine.h> header.

Cc: Andrew Victor <linux@maxim.org.za>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: Alexandre Courbot <gnurou@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-28 12:23:35 +02:00
Guenter Roeck f7d4ad98fd gpiolib: Export gpiochip_request_own_desc and gpiochip_free_own_desc
Both functions were introduced to let gpio drivers request their own
gpio pins. Without exporting the functions, this can however only be
used by gpio drivers built into the kernel.

Secondary impact is that the functions can not currently be used by
platform initialization code associated with the gpio-pca953x driver.
This code permits auto-export of gpio pins through platform data, but
if this functionality is used, the module can no longer be unloaded due
to the problem solved with the introduction of gpiochip_request_own_desc
and gpiochip_free_own_desc.

Export both function so they can be used from modules and from
platform initialization code.

Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-24 10:25:00 +02:00
Alexandre Courbot d74be6dfea gpio: remove gpiod_lock/unlock_as_irq()
gpio_lock/unlock_as_irq() are working with (chip, offset) arguments and
are thus not using the old integer namespace. Therefore, there is no
reason to have gpiod variants of these functions working with
descriptors, especially since the (chip, offset) tuple is more suitable
to the users of these functions (GPIO drivers, whereas GPIO descriptors
are targeted at GPIO consumers).

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-23 17:43:24 +02:00
Alexandre Courbot 1bd6b601fe gpio: make gpiochip_get_desc() gpiolib-private
As GPIO descriptors are not going to remain unique anymore, having this
function public is not safe. Restrain its use to gpiolib since we have
no user outside of it.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-23 17:41:12 +02:00
Linus Walleij 14c8a620ba gpio: drop retval check enforcing from gpiochip_remove()
As we start to decomission the return value from gpiochip_remove()
the compilers emit warnings due to the function being tagged
__must_check. So drop this until we remove the return value
altogether.

Cc: Abdoulaye Berthe <berthe.ab@gmail.com>
Suggested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-23 10:47:49 +02:00
Linus Walleij 1c8732bb03 gpio: support threaded interrupts in irqchip helpers
Some off-chip GPIO expanders need to be communicated by I2C or
SPI traffic, but may still support IRQs. By the sleeping nature
of such buses, such IRQ handlers need to be threaded. Support
such handlers in the gpiochip irqchip helpers by flagging IRQs
as threaded if the .can_sleep property of the gpiochip is
true.

Helpfully deny registration of chained IRQ handlers if the
.can_sleep property is set, as such chips will invariably need
a nested handler rather than a chained handler.

Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-04-28 12:35:07 -07:00
Linus Walleij c3626fdea0 gpio: unmap gpio irqs properly
When using the irqchip helper inside the gpiolib, make sure
the IRQs are unmapped/disposed before the irqdomain is removed
as part of removing the gpiochip.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-03-28 20:42:01 +01:00
Linus Walleij 1425052097 gpio: add IRQ chip helpers in gpiolib
This provides a function gpiochip_irqchip_add() to set
up an irqchip for a GPIO controller, and a function
gpiochip_set_chained_irqchip() to chain it to a parent
irqchip.

Most GPIOs are of the type where a number of lines form
a cascaded interrupt controller chained onto
the primary system interrupt controller (or further down the
chain) so let's add this helper and factor the code to
request the lines to be used as IRQs, the .to_irq() function
and the irqdomain into the core as well.

Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-03-26 10:31:21 +01:00
Alexandre Courbot bb1e88ccb7 gpiolib: add gpiochip_get_desc() driver function
Some drivers dealing with a gpio_chip might need to act on its
descriptors directly; one example is pinctrl drivers that need to lock a
GPIO for being used as IRQ using gpiod_lock_as_irq().

This patch exports a gpiochip_get_desc() function that returns the
GPIO descriptor at the requested index. It also sweeps the
gpio_to_chip() function out of the consumer interface since any holder
of a gpio_chip reference can manipulate its GPIOs way beyond what a
consumer should be allowed to do.

As a result, gpio_chip is not visible anymore to simple GPIO consumers.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Jean-Jacques Hiblot <jjhiblot@traphandler.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-02-12 17:11:35 +01:00
Andy Shevchenko f9244ae5dc gpiolib: convert gpiod_lookup description to kernel-doc
The patch moves description of the fields to the top of struct definition and
converts them to the kernel-doc format.

There is no functional change.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-12-09 14:18:33 +01:00
Alexandre Courbot ad824783fb gpio: better lookup method for platform GPIOs
Change the format of the platform GPIO lookup tables to make them less
confusing and improve lookup efficiency.

The previous format was a single linked-list that required to compare
the device name and function ID of every single GPIO defined for each
lookup. Switch that to a list of per-device tables, so that the lookup
can be done in two steps, omitting the GPIOs that are not relevant for a
particular device.

The matching rules are now defined as follows:
- The device name must match *exactly*, and can be NULL for GPIOs not
  assigned to a particular device,
- If the function ID in the lookup table is NULL, the con_id argument of
  gpiod_get() will not be used for lookup. However, if it is defined, it
  must match exactly.
- The index must always match.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-12-09 14:05:51 +01:00
Linus Walleij bdc54ef45d Linux 3.13-rc3
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Merge tag 'v3.13-rc3' into devel

Linux 3.13-rc3
2013-12-09 14:04:37 +01:00
Linus Walleij 9fb1f39eb2 gpio/pinctrl: make gpio_chip members typed boolean
This switches the two members of struct gpio_chip that were
defined as unsigned foo:1 to bool, because that is indeed what
they are. Switch all users in the gpio and pinctrl subsystems
to assign these values with true/false instead of 0/1. The
users outside these subsystems will survive since true/false
is 1/0, atleast we set some kind of more strict typing example.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-12-04 14:42:46 +01:00
Alexandre Courbot c9a9972b6f gpiolib: add missing declarations
Add declaration of 'struct of_phandle_args' to avoid the following
warning:

  In file included from arch/arm/mach-tegra/board-paz00.c:21:0:
  include/linux/gpio/driver.h:102:17: warning: 'struct of_phandle_args' declared inside parameter list
  include/linux/gpio/driver.h:102:17: warning: its scope is only this definition or declaration, which is probably not what you want

Also proactively add other definitions/includes that could be missing
in other contexts.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reported-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-12-03 13:10:47 +01:00
Alexandre Courbot 53e7cac35d gpiolib: use dedicated flags for GPIO properties
GPIO mapping properties were defined using the GPIOF_* flags, which are
declared in linux/gpio.h. This file is not included when using the
GPIO descriptor interface.

This patch declares the flags that can be used as GPIO mappings
properties in linux/gpio/driver.h, and uses them in gpiolib, so that no
deprecated declarations are used by the GPIO descriptor interface.

This patch also allows GPIO_OPEN_DRAIN and GPIO_OPEN_SOURCE to be
specified as GPIO mapping properties.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-11-25 09:03:12 +01:00
Stephen Rothwell f3ed0b6648 gpiolib: provide a declaration of seq_file in gpio/driver.h
Fixes this build error:

In file included from include/asm-generic/gpio.h:13:0,
                 from include/linux/gpio.h:51,
                 from include/linux/of_gpio.h:20,
                 from arch/powerpc/sysdev/ppc4xx_gpio.c:29:
include/linux/gpio/driver.h:85:14: error: 'struct seq_file' declared inside=
 parameter list [-Werror]
include/linux/gpio/driver.h:85:14: error: its scope is only this definition=
 or declaration, which is probably not what you want [-Werror]

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-10-29 18:26:15 -07:00
Alexandre Courbot bae48da237 gpiolib: add gpiod_get() and gpiod_put() functions
Add gpiod_get(), gpiod_get_index() and gpiod_put() functions that
provide safer management of GPIOs.

These functions put the GPIO framework in line with the conventions of
other frameworks in the kernel, and help ensure every GPIO is declared
properly and valid while it is used.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-10-19 23:24:56 +02:00
Alexandre Courbot 79a9becda8 gpiolib: export descriptor-based GPIO interface
This patch exports the gpiod_* family of API functions, a safer
alternative to the legacy GPIO interface. Differences between the gpiod
and legacy gpio APIs are:

- gpio works with integers, whereas gpiod operates on opaque handlers
  which cannot be forged or used before proper acquisition
- gpiod get/set functions are aware of the active low state of a GPIO
- gpio consumers should now include <linux/gpio/consumer.h> to access
  the new interface, whereas chips drivers will use
  <linux/gpio/driver.h>

The legacy gpio API is now built as inline functions on top of gpiod.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-10-19 23:24:45 +02:00