Some devices drivers make use of optional GPIO parameters. For such
drivers, it is important to discriminate between the case where no
GPIO mapping has been defined for the function they are requesting, and
the case where a mapping exists but an error occured while resolving it
or when acquiring the GPIO.

This patch changes the family of gpiod_get() functions such that they
will return -ENOENT if and only if no GPIO mapping is defined for the
requested function. Other error codes are used when an actual error
occured during the GPIO resolution.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Reviewed-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 patch just accents that @dev could be NULL.

There is no functional change.
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>

In several places we are printing messages with prefix based on chip->label.
Introduced macros help us to do this easier and in uniform way.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This patch includes the following amendments:
 1) use "?" as a label when the last one is not defined in gpiod_*;
 2) whenever it's possible gpiod_* are used;
 3) print a function name, if it's already used in other messages.

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

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

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

gpiochip_offset_to_desc() was using gpio_to_desc(), which directly
addresses the global GPIO array we are hoping to get rid of someday.
Reimplement it using the descriptor array of the chip itself, after
checking the requested offset is within the valid bounds of the chip.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

It's the drivers responsibility to react on failure to get
the gpio descriptors and not the frameworks. Since there are
some common peripherals that may or may not have certain
pins connected to gpio lines, depending on the platform,
printing the warning there may end up generating useless bug
reports.
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

For platforms that use device tree or ACPI as the standard way to look
GPIOs up, allow the platform-defined GPIO mappings to be used as a
fallback. This may be useful for platforms that need extra GPIOs mappings
not defined by the firmware.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

A typo resulted in GPIO lookup failing unconditionally.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Reported-by: NStephen Warren <swarren@wwwdotorg.org>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The prototype for static GPIO lookup functions has been updated to use
an explicit type for GPIO lookup flags. Unfortunately the definition of
of_find_gpio() when CONFIG_OF is not defined has been omitted, which
triggers a warning. This patch fixes this.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Signed-off-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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

find_chip_by_name() was incorrectly implemented by using
gpio_lookup_list instead of gpiod_chips to iterate through all the
registered GPIO controllers. This patch reimplements it by using
gpiochip_find() with a custom search function, which simplifies the code
on top of fixing the mistake.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Modify struct acpi_dev_node to contain a pointer to struct acpi_device
associated with the given device object (that is, its ACPI companion
device) instead of an ACPI handle corresponding to it.  Introduce two
new macros for manipulating that pointer in a CONFIG_ACPI-safe way,
ACPI_COMPANION() and ACPI_COMPANION_SET(), and rework the
ACPI_HANDLE() macro to take the above changes into account.
Drop the ACPI_HANDLE_SET() macro entirely and rework its users to
use ACPI_COMPANION_SET() instead.  For some of them who used to
pass the result of acpi_get_child() directly to ACPI_HANDLE_SET()
introduce a helper routine acpi_preset_companion() doing an
equivalent thing.

The main motivation for doing this is that there are things
represented by struct acpi_device objects that don't have valid
ACPI handles (so called fixed ACPI hardware features, such as
power and sleep buttons) and we would like to create platform
device objects for them and "glue" them to their ACPI companions
in the usual way (which currently is impossible due to the
lack of valid ACPI handles).  However, there are more reasons
why it may be useful.

First, struct acpi_device pointers allow of much better type checking
than void pointers which are ACPI handles, so it should be more
difficult to write buggy code using modified struct acpi_dev_node
and the new macros.  Second, the change should help to reduce (over
time) the number of places in which the result of ACPI_HANDLE() is
passed to acpi_bus_get_device() in order to obtain a pointer to the
struct acpi_device associated with the given "physical" device,
because now that pointer is returned by ACPI_COMPANION() directly.
Finally, the change should make it easier to write generic code that
will build both for CONFIG_ACPI set and unset without adding explicit
compiler directives to it.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> # on Haswell
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Aaron Lu <aaron.lu@intel.com> # for ATA and SDIO part

The ACPI GpioInt resources contain polarity field that is used to specify
whether the interrupt is active high or low. Since gpiolib supports
GPIOF_ACTIVE_LOW we can pass this information in the flags field in
acpi_find_gpio(), analogous to the DeviceTree version.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

gpiod_get_index() and gpiod_get() are now the new preferred way to request
GPIOs. Add support for finding the corresponding GPIO descriptor from ACPI
namespace.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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

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

This patch adds the infrastructure required to register non-linear gpio
ranges through gpiolib and the standard GPIO device tree bindings.
Signed-off-by: NChristian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

It is currently often possible in many GPIO drivers to request
a GPIO line to be used as IRQ after calling gpio_to_irq() and,
as the gpiolib is not aware of this, set the same line to
output and start driving it, with undesired side effects.

As it is a bogus usage scenario to request a line flagged as
output to used as IRQ, we introduce APIs to let gpiolib track
the use of a line as IRQ, and also set this flag from the
userspace ABI.

The API is symmetric so that lines can also be flagged from
.irq_enable() and unflagged from IRQ by .irq_disable().
The debugfs file is altered so that we see if a line is
reserved for IRQ.

Cc: Enric Balletbo i Serra <eballetbo@gmail.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NAlexandre Courbot <acourbot@nvidia.com>
Reviewed-by: NStephen Warren <swarren@nvidia.com>
Reviewed-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Patch be1a4b brought some improvements to the GPIO error handling code,
but also changed the return value of gpiod_request() when called on a
not yet initialized GPIO descriptor: it now returns -EINVAL instead of
-EPROBE_DEFER, and this affects some drivers.

This patch restores the original behavior for gpiod_request(). It is
safe to do so now that desc_to_gpio() does not rely on the GPIO
descriptor to be initialized. Other functions changed by patch be1a4b
do not see their return value affected, so these are not reverted.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Reported-by: NDr. H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The current implementation of desc_to_gpio() relies on the chip pointer
to be set to a valid value in order to compute the GPIO number. This
was done in the hope that we can get rid of the gpio_desc global array,
but this is not happening anytime soon.

This patch reimplements desc_to_gpio() in a fashion similar to that of
gpio_to_desc(). As a result, desc_to_gpio(gpio_to_desc(gpio)) == gpio is
now always true. This allows to call desc_to_gpio() on non-initialized
descriptors as some error-handling code currently does.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Reported-by: NDr. H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The pre-existing sysfs interfaces which take explicit namespace
argument are weird in that they place the optional @ns in front of
@name which is contrary to the established convention.  For example,
we end up forcing vast majority of sysfs_get_dirent() users to do
sysfs_get_dirent(parent, NULL, name), which is silly and error-prone
especially as @ns and @name may be interchanged without causing
compilation warning.

This renames sysfs_get_dirent() to sysfs_get_dirent_ns() and swap the
positions of @name and @ns, and sysfs_get_dirent() is now a wrapper
around sysfs_get_dirent_ns().  This makes confusions a lot less
likely.

There are other interfaces which take @ns before @name.  They'll be
updated by following patches.

This patch doesn't introduce any functional changes.

v2: EXPORT_SYMBOL_GPL() wasn't updated leading to undefined symbol
    error on module builds.  Reported by build test robot.  Fixed.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

gpiod_get/set functions share common code between their regular and
cansleep variants. The exporting of the gpiod interface will make
the situation worse. This patch factorizes the common code to avoid code
redundancy.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Provide the human readable label for the GPIO as well as the number when
we are recording it in order to improve the readability of log messages.
Signed-off-by: NMark Brown <broonie@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Currently many but not all GPIO log messages log the GPIO number and the
formats vary. Ensure that this is done consistently by defining logging
helpers which take the GPIO descriptor.

The will help people pattern matching on logs and providing the number
makes the log messages that omitted it more useful.
Signed-off-by: NMark Brown <broonie@linaro.org>
Acked-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

It appears some drivers are using gpio_set_debounce()
opportunistically, i.e. without knowing whether it works or
not. (Example: input/keyboard/gpio_keys.c) to account for
this use case, return -ENOTSUPP and do not print any
warnings in this case.

Took a round over the other gpio_set_debounce() consumers
to make sure that none of them are relying on the returned
error code to be something specific.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

At several places the gpiolib will proceed to handle a GPIO
descriptor even if it's ->chip member is NULL and no gpiochip
is associated.

Fix this by checking that both the descriptor cookie *and*
the chip pointer are valid.

Also bail out earlier with more specific diagnostic messages
on missing operations for setting as input/output or debounce.

ChangeLog v1->v2:
- Also return -EIO on gpiod_set_debounce() with missing
  operations in the vtable
- Fix indentations.
Suggested-by: NAlexandre Courbot <acourbot@nvidia.com>
Acked-by: NAlexandre Courbot <acourbot@nvidia.com>
Reviewed-by: NFrank Rowand <frank.rowand@sonymobile.com>
Cc: Tim Bird <tim.bird@sonymobile.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The usage of strict_strtol() is not preferred, because
strict_strtol() is obsolete. Thus, kstrtol() should be
used.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Move of_gpiochip_add outof spin_lock, since kzalloc inside
of_gpiochip_add -> of_gpiochip_add_pin_range -> gpiochip_add_pin_range -> kzalloc

WARNING: at kernel/lockdep.c:2740 lockdep_trace_alloc+0xf8/0xfc()
DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags))
Signed-off-by: NZhangfei Gao <zhangfei.gao@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This comment applies to gpio_to_chip(), not gpiod_to_chip().
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Constify descriptor parameter of gpiod_* functions for those that
should obviously not modify it. This includes value or direction get,
cansleep, and IRQ number query.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Some functions dereferenced their GPIO descriptor argument without
checking its validity first, potentially leading to an oops when given
an invalid argument.

This patch also makes gpio_get_value() more resilient when given an
invalid GPIO, returning 0 instead of silently crashing.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Cc: Ryan Mallon <rmallon@gmail.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Convert to the much saner new idr interface.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The debugfs files really need to hold the gpiolib spinlock before
accessing the list. Otherwise chip addition/removal will cause an oops.

Cc: Alexandre Courbot <acourbot@nvidia.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Add a pointer to the gpio_chip structure that references the array of
GPIO descriptors belonging to the chip, and update gpiolib code to use
this pointer instead of the global gpio_desc[] array. This is another
step towards the removal of the gpio_desc[] global array.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.orh>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Make sure gpiolib works internally with descriptors and (chip, offset)
pairs instead of using the global integer namespace. This prepares the
ground for the removal of the global gpio_desc[] array and the
introduction of the descriptor-based GPIO API.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
[grant.likely: Squash in fix for link error when CONFIG_SYSFS=n]
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Re-implement gpiochip_find_base using the list of chips instead of the
global gpio_desc[] array. This makes it both simpler and more efficient,
and is needed to remove the global descriptors array.

The new code should preserve the exact same GPIO number assignment
policy as the code it is replacing. There shouldn't be any visible
change to the assigned GPIO numbers.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
[grant.likely: Added comment about assignment policy]
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

This makes the code both simpler and faster compared to parsing the GPIO
number space.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>