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>

This refactors the changes to the GPIO line naming mechanism to
not have so widespread effects, instead we conclude the patch series
by having created a name attribute in the GPIO descriptor, that need
not be globally unique, and it will be initialized from the old
.names array in struct gpio_chip if it exists, then used in the legacy
sysfs code like the array was used previously.

The associated changes to name lines from the device tree are
controversial and need to stand alone from this. Resulting changes:

1. Remove the export and the header for the gpio_name_to_desc() as so
far the only use is inside gpiolib.c. Staticize gpio_name_to_desc()
and move it above the only function using it.

2. Only print a warning if there are two GPIO lines with the same name.
The reason is to preserve current behaviour: before the previous
changes to the naming mechanism this would not reject probing the
driver, instead the error would occur when trying to export the line
in sysfs, so restore this behaviour, but print a friendly warning
if names collide.

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

The latest gpio hogging mechanism assigns each gpio a 'line-name' in the
devicetree. The 'name' field is different from the 'label' field.
'label' is only used for requested GPIOs to describe its current use by
driver or userspace.

The 'name' field describes the GPIO itself, not the use. This is most
likely identical to the label in the schematic on the GPIO line and
should help to find this particular GPIO.

This is equivalent to the gpiochip->names array. However names should be
stored in the GPIO descriptor. We will use gpiochip->names in the future
only as initializer for the GPIO descriptors for drivers that assign
GPIO names hardcoded. All other GPIO names will be parsed from DT and
directly assigned to the GPIO descriptor.

This patch adds a helper function to find gpio descriptors by name
instead of gpio number.
Signed-off-by: NMarkus Pargmann <mpa@pengutronix.de>
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>

In case we unload and load a driver module again that is registering a
lookup table, without this it will result in multiple entries. Provide
an option to remove the lookup table on driver unload

Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Acked-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

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

Now that all[1] users of the gpiod_get functions are converted to make
use of the up to now optional flags parameter, make it mandatory which
allows to remove some cpp magic.

[1] all but etraxfs-uart which is broken anyhow and I'm allowed to
    ignore it by Jesper Nilsson :-)
Acked-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>

There have been concerns that the function names gpiod_set_array() and
gpiod_get_array() might be confusing to users. One might expect
gpiod_get_array() to return array values, while it is actually the array
counterpart of gpiod_get(). To be consistent with the single descriptor API
we could rename gpiod_set_array() to gpiod_set_array_value(). This makes
some function names a bit lengthy: gpiod_set_raw_array_value_cansleep().
Signed-off-by: NRojhalat Ibrahim <imr@rtschenk.de>
Acked-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

If GPIOLIB=n:

    drivers/leds/leds-gpio.c: In function ‘gpio_leds_create’:
    drivers/leds/leds-gpio.c:187: error: implicit declaration of function ‘devm_get_gpiod_from_child’
    drivers/leds/leds-gpio.c:187: warning: assignment makes pointer from integer without a cast

Add dummies for fwnode_get_named_gpiod() and devm_get_gpiod_from_child()
for the !GPIOLIB case to fix this.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Fixes: 40b73183 ("gpio: Support for unified device properties interface")
Acked-by: NAlexandre Courbot <acourbot@nvidia.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NBryan Wu <cooloney@gmail.com>

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>

Remove gpiod_sysfs_set_active_low (and gpio_sysfs_set_active_low) which
allowed code to change the polarity of a gpio line even after it had
been exported through sysfs.

Drivers should not care, and generally does not know, about gpio-line
polarity which is a hardware feature that needs to be described by
firmware.

It is currently possible to define gpio-line polarity in device-tree and
acpi firmware or using platform data. Userspace can also change the
polarity through sysfs.

Note that drivers using the legacy gpio interface could still use
GPIOF_ACTIVE_LOW to change the polarity before exporting the gpio.

There are no in-kernel users of this interface.

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Harry Wei <harryxiyou@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@zh-kernel.org
Cc: linux-arch@vger.kernel.org
Signed-off-by: NJohan Hovold <johan@kernel.org>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.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>

Add device managed variants of gpiod_get_array() / gpiod_put_array()
functions for conveniently obtaining and disposing of an entire array
of GPIOs with one function call.
Signed-off-by: NRojhalat Ibrahim <imr@rtschenk.de>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Introduce new functions for conveniently obtaining and disposing of
an entire array of GPIOs with one function call.

ACPI parts tested by Mika Westerberg, DT parts tested by Rojhalat
Ibrahim.

Change log:
v5: move the ACPI functions to gpiolib-acpi.c
v4: - use shorter names for members of struct gpio_descs
    - rename lut_gpio_count to platform_gpio_count for clarity
    - add check for successful memory allocation
    - use ERR_CAST()
v3: - rebase on current linux-gpio devel branch
    - fix ACPI GPIO counting
    - allow for zero-sized arrays
    - make the flags argument mandatory for the new functions
    - clarify documentation
v2: change interface
Suggested-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NRojhalat Ibrahim <imr@rtschenk.de>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: NRojhalat Ibrahim <imr@rtschenk.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The gpio binding document says that new code should always use named
gpios. Patch 40b73183 added support to parse a list of gpios from child
nodes, but does not make it possible to use named gpios. This patch adds
the con_id property and implements it is done in gpiolib.c, where the
old-style of using unnamed gpios still works.
Signed-off-by: NOlliver Schinagl <oliver@schinagl.nl>
Acked-by: NBryan Wu <cooloney@gmail.com>
Acked-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Right now, in consumer.h, there's some vararg hacks that pass 0 as the
flags. What actually is passed however is GPIOD_ASIS, which naturally is
also 0. Using the define/enum rather then the magic 0 makes it the
define more readable to a passer by.
Signed-off-by: NOlliver Schinagl <oliver@schinagl.nl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Although gpiod_get_direction() can be considered side-effect free for
consumers, its internals involve setting or clearing bits in the
affected GPIO descriptor, for which we need to force-cast the const
descriptor variable to non-const. This could lead to incorrect behavior
if the compiler decides to optimize here, so remove this const
attribute. The intent is to make gpiod_get_direction() private anyway,
so it does not really matter.
Reported-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
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>

Some drivers need to deal with only firmware representation of its
GPIOs. An example would be a GPIO button array driver where each button
is described as a separate firmware node in device tree. Typically these
child nodes do not have physical representation in the Linux device
model.

In order to help device drivers to handle such firmware child nodes we
add dev[m]_get_named_gpiod_from_child() that takes a child firmware
node pointer as its second argument (the first one is the parent device
itself), finds the GPIO using whatever is the underlying firmware
method, and requests the GPIO properly.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NAlexandre Courbot <acourbot@nvidia.com>
Acked-by: NGrant Likely <grant.likely@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

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>

commit 39b2bbe3
"gpio: add flags argument to gpiod_get*() functions"
added a dynamic flags argument to all the GPIOD getter
functions, however this did not cover the stubs so
when people used gpiod stubs to compile out descriptor
code, compilation failed.

Solve this by:
- Also rename all the stub functions __gpiod_*
- Moving the vararg hack outside of #ifdef CONFIG_GPIOLIB
  so these will always be available.
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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>

The GPIOD flags are defined inside the #ifdef CONFIG_GPIOLIB
switch, making the gpiolib stubs fail if these flags are used
by a consumer. This is not correct: the stubs should compile
fine without GPIOLIB.
Reported-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

linux/types.h and linux/list.h should be included so the typed used in
the header file are always properly declared.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Reported-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>