Most shared headers in include/linux don't need to know what the
internals of a struct module are; all they care about is that it
is a struct and hence they may require a pointer to one.

The advantage in this is that module.h is including a lot of stuff
itself, and an otherwise empty C file that just contains module.h
will result in ~750kB from CPP (compared to say 12kB from init.h)

So we have approximately 50 instances of "struct module;" in the
various include/linux headers already that help us keep module.h
out of other headers; here we do the same for gpio.

Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: linux-gpio@vger.kernel.org
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Some GPIO controllers has a special hardware bit we can flip
to support open drain / source. This means that on these hardwares
we do not need to emulate OD/OS by setting the line to input
instead of actively driving it high/low. Add an optional vtable
callback to the driver set_single_ended() so that driver can
implement this in hardware if they have it.

We may need a pinctrl_gpio_set_config() call at some point to
propagate this down to a backing pin control device on systems
with split GPIO/pin control.
Reported-by: NMichael Hennerich <michael.hennerich@analog.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add device managed APIs devm_gpiochip_add_data() and
devm_gpiochip_remove() for the APIs gpiochip_add_data()
and gpiochip_remove().

This helps in reducing code in error path and sometimes
removal of .remove callback for driver unbind.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>

The gpio_chip label is useful for userspace to understand what
kind of GPIO chip it is dealing with. Let's store a copy of this
label in the gpio_device, add it to the struct passed to userspace
for GPIO_GET_CHIPINFO_IOCTL and modify lsgpio to show it.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

My left hand merges code to privatize the descriptor handling
while my right hand merges drivers that poke around and
disrespect with the same gpiolib internals.

So let's expose the proper APIs for drivers to ask the gpiolib
core if a line is marked as open drain or open source and
get some order around things so this driver compiles again.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Cc: Nicolas Saenz Julienne <nicolassaenzj@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

We move to manage this pointer under gpiolib control rather than
leave it in the subdevice's gpio_chip. We can not NULL it after
gpiochip_remove so at to keep things tight.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Instead of keeping this reference to the pin ranges in the
client driver-supplied gpio_chip, move it to the internal
gpio_device as the drivers have no need to inspect this.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This kind of hacks disturbs the refactoring of the gpiolib.

The descriptor table belongs to the gpiolib, if we want to know
something about something in it, use or define the proper accessor
functions. Let's add this gpiochip_lins_is_irq() to do what the
sunxi driver is trying at so we can privatize the descriptors
properly.

Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

We need gpio_device to hold the descriptors so that they can
be lifecycled with the struct gpio_device held from userspace.
Move the descriptor array into gpio_device. Also rename it from
"desc" (singularis) to "descs" (pluralis) to reflect the fact
that it is an array.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Since gpio_device is the struct that survives if the backing
gpio_chip is removed, move the sysfs mock device to this state
container so it becomes part of the dangling state of the
GPIO device on removal.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

GPIO chips have been around for years, but were never real devices,
instead they were piggy-backing on a parent device (such as a
platform_device or amba_device) but this was always optional.
GPIO chips could also exist without any device at all, with its
struct device *parent (ex *dev) pointer being set to null.

When sysfs was in use, a mock device would be created, with the
optional parent assigned, or just floating orphaned with NULL
as parent.

If sysfs is active, it will use this device as parent.

We now create a gpio_device struct containing a real
struct device and move the subsystem over to using that. The
list of struct gpio_chip:s is augmented to hold struct
gpio_device:s and we find gpio_chips:s by first looking up
the struct gpio_device.

The struct gpio_device is designed to stay around even if the
gpio_chip is removed, so as to satisfy users in userspace
that need a backing data structure to hold the state of the
session initiated with e.g. a character device even if there is
no physical chip anymore.

From this point on, gpiochips are devices.

Cc: Johan Hovold <johan@kernel.org>
Cc: Michael Welling <mwelling@ieee.org>
Cc: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Board files that define their own bgpio_pdata are broken when
CONFIG_GPIO_GENERIC is disabled and the bgpio_pdata structure
definition is hidden by the #ifdef:

arch/arm/mach-clps711x/board-autcpu12.c:148:15: error: variable 'autcpu12_mmgpio_pdata' has initializer but incomplete type
 static struct bgpio_pdata autcpu12_mmgpio_pdata __initdata = {
arch/arm/mach-clps711x/board-autcpu12.c:149:2: error: unknown field 'base' specified in initializer
  .base = AUTCPU12_MMGPIO_BASE,

Since the board files should generally not care what drivers are
enabled, this makes the structure definition visible again.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Fixes: 0f4630f3 ("gpio: generic: factor into gpio_chip struct")
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The separate struct bgpio_chip has been a pain to handle, both
by being confusingly similar in name to struct gpio_chip and
for being contained inside a struct so that struct gpio_chip
is contained in a struct contained in a struct, making several
steps of dereferencing necessary.

Make things simpler: include the fields directly into
<linux/gpio/driver.h>, #ifdef:ed for CONFIG_GENERIC_GPIO, and
get rid of the <linux/basic_mmio_gpio.h> altogether. Prefix
some of the member variables with bgpio_* and add proper
kerneldoc while we're at it.

Modify all users to handle the change and use a struct
gpio_chip directly. And while we're at it: replace all
container_of() dereferencing by gpiochip_get_data() and
registering the gpio_chip with gpiochip_add_data().

Cc: arm@kernel.org
Cc: Alexander Shiyan <shc_work@mail.ru>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Cc: Rabin Vincent <rabin@rab.in>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-omap@vger.kernel.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: bcm-kernel-feedback-list@broadcom.com
Acked-by: NGregory Fong <gregory.0xf0@gmail.com>
Acked-by: NLiviu Dudau <Liviu.Dudau@arm.com>
Acked-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Acked-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This adds a void * pointer to gpio_chip so that driver can
assign and retrieve some states. This is done to get rid of
container_of() calls for gpio_chips embedded inside state
containers, so we can remove the need to have the gpio_chip
or later (planned) struct gpio_device be dynamically allocated
at registration time, so that its struct device can be properly
reference counted and not bound to its parent device (e.g.
a platform_device) but instead live on after unregistration
if it is opened by e.g. a char device or sysfs.

The data is added with the new function gpiochip_add_data()
and for compatibility we add static inline wrapper function
gpiochip_add() that will call gpiochip_add_data() with
NULL as argument. The latter will be removed once we have
exorcised gpiochip_add() from the kernel.

gpiochip_get_data() is added as a static inline accessor
for drivers to quickly get their data out.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NVladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NLee Jones <lee.jones@linaro.org>
Acked-by: NJiri Kosina <jkosina@suse.cz>
Acked-by: NHans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: NJacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NJonas Gorski <jogo@openwrt.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add missed description for GPIO irqchip fields in struct gpio_chip.
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NRoger Quadros <rogerq@ti.com>
Tested-by: NRoger Quadros <rogerq@ti.com>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Clean up chained handler and handler data if they were set by
gpiochip_set_chained_irqchip().
Signed-off-by: NDmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NJohan Hovold <johan@kernel.org>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NRojhalat Ibrahim <imr@rtschenk.de>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Reviewed-by: NMark Brown <broonie@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NOctavian Purdila <octavian.purdila@intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This avoids handling gpiochip remove error in device
remove handler.
Signed-off-by: NAbdoulaye Berthe <berthe.ab@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

These two typos were introduced in commit 14250520 ("gpio: add IRQ
chip helpers in gpiolib").

The correct symbol name is CONFIG_GPIOLIB_IRQCHIP.

[jkosina@suse.cz: add changelog]
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

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: NAlexandre Courbot <acourbot@nvidia.com>
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NStephen Warren <swarren@wwwdotorg.org>
Reviewed-by: NAlexandre Courbot <gnurou@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NAlexandre Courbot <acourbot@nvidia.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NLinus Walleij <linus.walleij@linaro.org>

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: NLinus Walleij <linus.walleij@linaro.org>

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: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NAlexandre Courbot <acourbot@nvidia.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NJean-Jacques Hiblot <jjhiblot@traphandler.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NAlexandre Courbot <acourbot@nvidia.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>