Add a hardirq handler to the GPIO userspace event loop, making
sure to pick up the timestamp there, as close as possible in time
relative to the actual event causing the interrupt.

Tested with a simple pushbutton GPIO on ux500 and seems to work
fine.

Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Reported-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The GPIO event descriptor was leaking kernel stack to
userspace because we don't zero the variable before
use. Ooops. Fix this.

Cc: stable@vger.kernel.org
Reported-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NBartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The initialized value stored in pointer desc is never read as it
is updated in the first executable statement in the function.
This is therefore redundant and can be removed.

Cleans up clang warning:
drivers/gpio/gpiolib.c:3710:20: warning: Value stored to 'desc'
during its initialization is never read
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Sometimes a GPIO is fetched with NULL as parent device, and
that is just fine. So under these circumstances, avoid using
dev_name() to provide a name for the GPIO line.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

We have been holding back on adding an API for fetching GPIO handles
directly from device nodes, strongly preferring to get it from the
spawn devices instead.

The fwnode interface however already contains an API for doing this,
as it is used for opaque device tree nodes or ACPI nodes for getting
handles to LEDs and keys that use GPIO: those are specified as one
child per LED/key in the device tree and are not individual devices.

However regulators present a special problem as they already have
helper functions to traverse the device tree from a regulator node
and two levels down to fill in data, and as it already traverses
GPIO nodes in its own way, and already holds a pointer to each
regulators device tree node, it makes most sense to export an
API to fetch the GPIO descriptor directly from the node.

We only support the devm_* version for now, hopefully no non-devres
version will be needed.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Sometimes a GPIO needs to be taken from a node without
a device associated with it. The fwnode accessor does this,
let's however break out the DT code for now.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Some pinctrl drivers can use the gpiochip irq valid information
to figure out if certain gpios are exposed to the kernel for
usage or not. Expose this API so we can use it in the
pinmux_ops::request ops.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Acked-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The use of the GPIOF_* flags is deprecated, so don't advertise them
here. Document the plain numbers for now until we have a better
solution.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Some GPIO lines appear named "?" in the lsgpio dump due to their
requesting drivers not passing a reasonable label.

Most typically this happens if a device tree node just defines
gpios = <...> and not foo-gpios = <...>, the former gets named
"foo" and the latter gets named "?".

However the struct device passed in is always valid so let's
just label the GPIO with dev_name() on the device if no proper
label was passed.

Cc: Reported-by: Jason Kridner <jkridner@beagleboard.org>
Reported-by: NJason Kridner <jkridner@beagleboard.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The gpiod_set_transitory() function is publicly exported, and
it is expected from it to be ready for usage with optional GPIOs
on consumer's side.
Signed-off-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This non-functional change slightly simplifies the implementation
of gpiod_to_chip() function.
Signed-off-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The fix restores a proper validation of an input gpio desc, which
might be needed to deal with optional GPIOs correctly.

Fixes: 02e47980 ("gpio: Alter semantics of *raw* operations to actually be raw")
Signed-off-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Signed-off-by: NJonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

While we do need macros to be able to return from the "calling"
function, we can still factor the checks done by the VALIDATE_DESC*
macros into a real helper function. This reduces the backslashtitis,
avoids duplicating the logic in the two macros and saves about 1K of
generated code:

$ scripts/bloat-o-meter drivers/gpio/gpiolib.o.{0,1}
add/remove: 1/0 grow/shrink: 0/15 up/down: 104/-1281 (-1177)
Function                                     old     new   delta
validate_desc                                  -     104    +104
gpiod_set_value                              192     135     -57
gpiod_set_raw_value                          125      67     -58
gpiod_direction_output                       412     351     -61
gpiod_set_value_cansleep                     150      70     -80
gpiod_set_raw_value_cansleep                 132      52     -80
gpiod_get_raw_value                          139      54     -85
gpiod_set_debounce                           226     140     -86
gpiod_direction_output_raw                   124      38     -86
gpiod_get_value                              161      74     -87
gpiod_cansleep                               126      39     -87
gpiod_get_raw_value_cansleep                 130      39     -91
gpiod_get_value_cansleep                     152      59     -93
gpiod_is_active_low                          128      33     -95
gpiod_request                                299     184    -115
gpiod_direction_input                        386     266    -120
Total: Before=25460, After=24283, chg -4.62%
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This reverts commit 72d32000.

We cannot blindly query the direction of all GPIOs when the pins are
first registered.  The get_direction callback normally triggers a
read/write to hardware, but we shouldn't be touching the hardware for
an individual GPIO until after it's been properly claimed.
Signed-off-by: NTimur Tabi <timur@codeaurora.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Users often pass a pointer to a static string to gpiochip_add_data()
family of functions. Avoid unnecessary memory allocations with the
provided helper routine.

While at it: use a ternary operator instead of an if else for brevity.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

General support for state persistence is added to gpiolib with the
introduction of a new pinconf parameter to propagate the request to
hardware. The existing persistence support for sleep is adapted to
include hardware support if the GPIO driver provides it. Persistence
continues to be enabled by default; in-kernel consumers can opt out, but
userspace (currently) does not have a choice.

The *_SLEEP_MAY_LOSE_VALUE and *_SLEEP_MAINTAIN_VALUE symbols are
renamed, dropping the SLEEP prefix to reflect that the concept is no
longer sleep-specific.  I feel that renaming to just *_MAY_LOSE_VALUE
could initially be misinterpreted, so I've further changed the symbols
to *_TRANSITORY and *_PERSISTENT to address this.

The sysfs interface is modified only to keep consistency with the
chardev interface in enforcing persistence for userspace exports.
Signed-off-by: NAndrew Jeffery <andrew@aj.id.au>
Reviewed-by: NCharles Keepax <ckeepax@opensource.cirrus.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If
the hardware actually supports enabling both at the same time the
electrical result would be disastrous.
Suggested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

We have the duplicated debug strings printed whenever
acpi_gpio_update_gpiod_flags() fails. Instead of doing this by callers,
move the debug output inside function.

In one case convert almost useless pr_debug() to dev_dbg() where
actual consumer of GPIO resource is disclosed.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The struct is wrong, this is named lock_class_key.

Cc: Thierry Reding <treding@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

In order to avoid lockdep boilerplate in individual drivers, turn the
gpiochip_add_data() function into a macro that creates a unique class
key for each driver.

Note that this has the slight disadvantage of adding a key for each
driver registered with the system. However, these keys are 8 bytes in
size, which is negligible and a small price to pay for generic
infrastructure.
Suggested-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NThierry Reding <treding@nvidia.com>
Acked-by: NGrygorii Strashko <grygorii.strashko@ti.com>
[renane __gpiochip_add_data() to gpiochip_add_data_with_key]
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Some GPIO chips cannot support sparse IRQ numbering and therefore need
to manually allocate their interrupt descriptors statically. For these
cases, a driver can pass the first allocated IRQ via the struct
gpio_irq_chip's "first" field and thereby cause the IRQ domain to map
all IRQs during initialization.
Suggested-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NThierry Reding <treding@nvidia.com>
Acked-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The nested field in struct gpio_irq_chip currently has two meanings. On
one hand it marks an IRQ chip as being nested (as opposed to chained),
while on the other hand it also means that an IRQ chip uses nested
thread handlers.

However, nested IRQ chips can already be identified by the fact that
they don't pass a parent handler (the driver would instead already have
installed a nested handler using request_irq()).

Therefore, the only use for the nested attribute is to inform gpiolib
that an IRQ chip uses nested thread handlers (as opposed to regular,
non-threaded handlers). To clarify its purpose, rename the field to
"threaded".
Signed-off-by: NThierry Reding <treding@nvidia.com>
Acked-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Export these functions so that drivers can explicitly use these when
setting up their IRQ domain.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Acked-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Currently GPIO drivers are required to add the GPIO chip and its
corresponding IRQ chip separately, which can result in a lot of
boilerplate. Use the newly introduced struct gpio_irq_chip, embedded in
struct gpio_chip, that drivers can fill in if they want the GPIO core
to automatically register the IRQ chip associated with a GPIO chip.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Acked-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

In order to consolidate the multiple ways to associate an IRQ chip with
a GPIO chip, move more fields into the new struct gpio_irq_chip.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Acked-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

In order to consolidate the multiple ways to associate an IRQ chip with
a GPIO chip, move more fields into the new struct gpio_irq_chip.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Acked-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

In order to consolidate the multiple ways to associate an IRQ chip with
a GPIO chip, move more fields into the new struct gpio_irq_chip.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Acked-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

In order to consolidate the multiple ways to associate an IRQ chip with
a GPIO chip, move more fields into the new struct gpio_irq_chip.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Acked-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

In order to consolidate the multiple ways to associate an IRQ chip with
a GPIO chip, move more fields into the new struct gpio_irq_chip.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Acked-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

In order to consolidate the multiple ways to associate an IRQ chip with
a GPIO chip, move more fields into the new struct gpio_irq_chip.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Acked-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

In order to consolidate the multiple ways to associate an IRQ chip with
a GPIO chip, move more fields into the new struct gpio_irq_chip.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Acked-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

In order to consolidate the multiple ways to associate an IRQ chip with
a GPIO chip, move more fields into the new struct gpio_irq_chip.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Acked-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Some busses, like I2C, strictly need to have the line handled
as open drain, i.e. not actively driven high. For this reason
the i2c-gpio.c bit-banged I2C driver is reimplementing open
drain handling outside of gpiolib.

This is not very optimal. Instead make it possible for a
consumer to explcitly express that the line must be handled
as open drain instead of allowing local hacks papering over
this issue.

The descriptor tables, whether DT, ACPI or board files, should
of course have flagged these lines as open drain. E.g.:
enum gpio_lookup_flags GPIO_OPEN_DRAIN for a board file, or
gpios = <&foo 42 GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN>; in a
device tree using <dt-bindings/gpio/gpio.h>

But more often than not, these descriptors are wrong. So
we need to make it possible for consumers to enforce this
open drain behaviour.

We now have two new enumerated GPIO descriptor config flags:
GPIOD_OUT_LOW_OPEN_DRAIN and GPIOD_OUT_HIGH_OPEN_DRAIN
that will set up the lined enforced as open drain as output
low or high, using open drain (if the driver supports it)
or using open drain emulation (setting the line as input
to drive it high) from the gpiolib core.

Cc: linux-gpio@vger.kernel.org
Tested-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Literally.

I expect "lose" was meant here, rather than "loose", though you could feasibly
use a somewhat uncommon definition of "loose" to mean what would be meant by
"lose": "Loose the hounds" for instance, as in "Release the hounds".
Substituting in "value" for "hounds" gives "release the value", and makes some
sense, but futher substituting back to loose gives "loose the value" which
overall just seems a bit anachronistic.

Instead, use modern, pragmatic English and save a character.

Cc: Russell Currey <ruscur@russell.cc>
Signed-off-by: NAndrew Jeffery <andrew@aj.id.au>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Replace the two separate calls for clearing the irqchip's chained handler
and its data with a single irq_set_chained_handler_and_data() call.
Signed-off-by: NMartin Kaiser <martin@kaiser.cx>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

OPEN_DRAIN and OPEN_SOURCE flags only affect the way we drive a GPIO
line, so they only make sense for output mode. Just as we only allow
input mode for event handle requests, don't allow passing open-drain
and open-source flags for any other mode than explicit output.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

There's no need to check the validity of handle request flags more
than once, right after copying the data from user. Move the check
out of the for loop and simplify the error path by bailing out before
allocating any resources.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

SPI-attached GPIO controllers typically read out all inputs in one go.
If callers desire the values of multipe inputs, ideally a single readout
should take place to return the desired values.  However the current
driver API only offers a ->get callback but no ->get_multiple (unlike
->set_multiple, which is present).  Thus, to read multiple inputs, a
full readout needs to be performed for every single value (barring
driver-internal caching), which is inefficient.

In fact, the lack of a ->get_multiple callback has been bemoaned
repeatedly by the gpio subsystem maintainer:
http://www.spinics.net/lists/linux-gpio/msg10571.html
http://www.spinics.net/lists/devicetree/msg121734.html

Introduce the missing callback.  Add corresponding consumer functions
such as gpiod_get_array_value().  Amend linehandle_ioctl() to take
advantage of the newly added infrastructure.  Update the documentation.

Cc: Rojhalat Ibrahim <imr@rtschenk.de>
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Currently calls to:
gpiod_direction_output_raw()
gpiod_set_raw_value()
gpiod_set_raw_array_value()
gpiod_set_raw_value_cansleep()
gpiod_set_raw_array_value_cansleep()

Respect that we do not want to invert the value written, but will
still apply special open drain/open source semantics if the line has
an open drain/open source flag.

It also forbids us from driving an output marked as an interrupt
line.

This does not fit with the function name and expected semantics. In
the w1 host driver (for example) we need to handle a line as open drain
but sometimes force it to pull up, which means we should be able to
use the gpiod_set_raw_value() for this, but it currently does not
work.

There are also use cases where users actually want to drive a line
used by an interrupt. This is what they should be expected to use
the *raw* accessors for.

I have looked over the current users of this API and they do not seem
to be using the *raw* accessors with open drain or open source so let's
augment this behaviour before we have users expecting the inconsistent
semantic.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>