Some broken ACPI tables might require quirks in the OS.
Introduce quirks field in struct acpi_gpio_mapping.

Propagate them to struct acpi_gpio_info for further use.
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>

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 further improvements are based on this change since
struct acpi_gpio_lookup is not available in some cases.
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>

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>

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>

In header files, static inline is more commonly used.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This allows ACPI GPIO code to modify flags based on
ACPI GpioIo() / GpioInt() resources.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This is preparatory patch for enabling GPIO ACPI to configure a pin
accordingly.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add new flags to allow users to specify that they are not concerned with
the status of GPIOs whilst in a sleep/low power state.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

It seems the code had been changed, but description left untouched.

Update description of the struct acpi_gpio_info and relative comments
accordingly.

Fixes: commit 52044723 ("ACPI / gpio: Add irq_type when a GPIO is used as an interrupt")
Cc: Christophe RICARD <christophe.ricard@gmail.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

In order to use "gpio-line-names" property in systems not having DT as
their boot firmware, rework of_gpiochip_set_names() to use device property
accessors. This reworked function is placed in a separate file making it
clear it deals with universal device properties.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

of_get_named_gpiod_flags() was missing a static inline version
when compiling without OF_GPIO. Add this.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

of_gpiochip_add() and of_gpiochip_remove() are only used locally
in the gpio subsystem so move these functions to the local
header.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The generic GPIO library directly implement code for acpi_find_gpio()
which is only used with CONFIG_ACPI. This was probably done because
OF did the same thing, but I removed that so remove this too.

Rename the internal acpi_find_gpio() in gpiolib-acpi.c to
acpi_populate_gpio_lookup() which seems to be more appropriate anyway
so as to avoid a namespace clash with the same function.

Make the stub return -ENOENT rather than -ENOSYS (as that is for
syscalls!).

For some reason the sunxi pin control driver was including the private
gpiolib header, it works just fine without it so remove that oneliner.

Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The generic GPIO library directly implement code for of_find_gpio()
which is only used with CONFIG_OF and causes compilation problems
on archs that do not even have stubs for OF functions, especially
on UM that does not implement any IO remap functions.

Move the function to gpiolib-of.c, implement a static inline stub
in gpiolib.h returning PTR_ERR(-ENOENT) if CONFIG_OF_GPIO is not
set and be done with it.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This renames gpiod_set_array_value_priv() to
gpiod_set_array_value_complex() and moves it to the gpiolib.h
private header file so we can reuse it in the subsystem.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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>

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>

Some information about the GPIO chip need to stay around also
after the gpio_chip has been removed and only the gpio_device
persist. The base and ngpio are such things, for example we
don't want a new chip arriving to overlap the number space
of a dangling gpio_device, and the chardev may still query
the device for the number of lines etc.

Note that the code that assigns base and insert gpio_device
into the global list no longer check for a missing gpio_chip:
we respect the number space allocated by any other gpio_device.

As a consequence of the gdev being referenced directly from
the gpio_desc, we need to verify it differently from all
in-kernel API calls that fall through to direct queries to
the gpio_chip vtable: we first check that desc is !NULL, then
that desc->gdev is !NULL, then, if desc->gdev->chip is NULL,
we *BAIL OUT* without any error, so as to manage the case
where operations are requested on a device that is gone.

These checks were non-uniform and partly missing in the past:
so to simplify: create the macros VALIDATE_DESC() that will
return -EINVAL if the desc or desc->gdev is missing and just
0 if the chip is gone, and conversely VALIDATE_DESC_VOID()
for the case where the function does not return an error.
By using these macros, we get warning messages about missing
gdev with reference to the right function in the kernel log.

Despite the macro business this simplifies the code and make
it more readable than if we copy/paste the same descriptor
checking code into all code ABI call sites (IMHO).
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>

A new chardev that is to be used for userspace GPIO access is
added in this patch. It is intended to gradually replace the
horribly broken sysfs ABI.

Using a chardev has many upsides:

- All operations are per-gpiochip, which is the actual
  device underlying the GPIOs, making us tie in to the
  kernel device model properly.

- Hotpluggable GPIO controllers can come and go, as this
  kind of problem has been know to userspace for character
  devices since ages, and if a gpiochip handle is held in
  userspace we know we will break something, whereas the
  sysfs is stateless.

- The one-value-per-file rule of sysfs is really hard to
  maintain when you want to twist more than one knob at a time,
  for example have in-kernel APIs to switch several GPIO
  lines at the same time, and this will be possible to do
  with a single ioctl() from userspace, saving a lot of
  context switching.

We also need to add a new bus type for GPIO. This is
necessary for example for userspace coldplug, where sysfs is
traversed to find the boot-time device nodes and create the
character devices in /dev.

This new chardev ABI is *non* *optional* and can be counted
on to be present in the future, emphasizing the preference
of this ABI.

The ABI only implements one single ioctl() to get the name
and number of GPIO lines of a chip. Even this is debatable:
see it as a minimal example for review. This ABI shall be
ruthlessly reviewed and etched in stone.

The old /sys/class/gpio is still optional to compile in,
but will be deprecated.

Unique device IDs are created using IDR, which is overkill
and insanely scalable, but also well tested.

Cc: Johan Hovold <johan@kernel.org>
Cc: Michael Welling <mwelling@ieee.org>
Cc: Markus Pargmann <mpa@pengutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

We use the new struct device inside gpio_chip to related debug
prints and warnings, and we also add it to the debugfs dump.

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>

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>

When a GPIO is used as an interrupt in ACPI, the irq_type was not
available for device driver.

Make available polarity and triggering information in acpi_find_gpio by
renaming acpi_gpio_info field active_low  to polarity and adding triggering
field (edge/level).

For sanity, in gpiolib.c replace info.active_low by
"info.polarity == GPIO_ACTIVE_LOW".

Set the irq_type if necessary in acpi_dev_gpio_irq_get.
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We should not fall back to the legacy unnamed gpio lookup style if the
driver requests gpios with different names, because we'll give out the same
gpio twice. Let's keep track of the names that were used for the device and
only do the fallback for the first name used.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This enum is used in the gpiolib.h header file, yet
<linux/gpio/consumer.h> is not included so plainly including this
file (and some drivers do) will raise compile problems.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

We should not fall back to the legacy unnamed gpio lookup style if the
driver requests gpios with different names, because we'll give out the same
gpio twice. Let's keep track of the names that were used for the device and
only do the fallback for the first name used.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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>

Make device_get_next_child_node() work with ACPI data-only subnodes
introduced previously.

Namely, replace acpi_get_next_child() with acpi_get_next_subnode()
that can handle (and return) child device objects as well as child
data-only subnodes of the given device and modify the ACPI part
of the GPIO subsystem to handle data-only subnodes returned by it.

To that end, introduce acpi_node_get_gpiod() taking a struct
fwnode_handle pointer as the first argument.  That argument may
point to an ACPI device object as well as to a data-only subnode
and the function should do the right thing (ie. look for the matching
GPIO descriptor correctly) in either case.

Next, modify fwnode_get_named_gpiod() to use acpi_node_get_gpiod()
instead of acpi_get_gpiod_by_index() which automatically causes
devm_get_gpiod_from_child() to work with ACPI data-only subnodes
that may be returned by device_get_next_child_node() which in turn
is required by the users of that function (the gpio_keys_polled
and gpio-leds drivers).
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>

Move irq trigger flags, which as sysfs-interface specific, to the class
device data.

This avoids accessing the gpio-descriptor flags field using non-atomic
operations without any locking, and allows for a more clear separation
of the sysfs interface from gpiolib core.
Signed-off-by: NJohan Hovold <johan@kernel.org>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Remove FLAG_SYSFS_DIR, which is sysfs-interface specific, and store it
in the class-device data instead.

Note that the flag is only used during export.
Signed-off-by: NJohan Hovold <johan@kernel.org>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Store the value sysfs entry in the gpiod data rather than in a global
table accessed through an index stored in the overloaded gpio-descriptor
flag field.
Signed-off-by: NJohan Hovold <johan@kernel.org>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Rename the gpio-chip export/unexport functions to the more descriptive
names gpiochip_sysfs_register and gpiochip_sysfs_unregister.
Signed-off-by: NJohan Hovold <johan@kernel.org>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Now that we have struct fwnode_handle, we can use that to point to
ACPI companions from struct device objects instead of pointing to
struct acpi_device directly.

There are two benefits from that.  First, the somewhat ugly and
hackish struct acpi_dev_node can be dropped and, second, the same
struct fwnode_handle pointer can be used in the future to point
to other (non-ACPI) firmware device node types.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NGrant Likely <grant.likely@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>

Avoid multiple identical definitions of the gpio suffix strings by putting
them into a global constant array.
Signed-off-by: NRojhalat Ibrahim <imr@rtschenk.de>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Based on Boris Brezillion's work this is a reworked patch
of his initial GPIO hogging mechanism.
This patch provides a way to initially configure specific GPIO
when the GPIO controller is probed.

The actual DT scanning to collect the GPIO specific data is performed
as part of gpiochip_add().

The purpose of this is to allow specific GPIOs to be configured
without any driver specific code.
This is particularly useful because board design are getting
increasingly complex and given SoC pins can now have more
than 10 mux values, a lot of connections are now dependent on
external IO muxes to switch various modes.

Specific drivers should not necessarily need to be aware of
what accounts to a specific board implementation. This board level
"description" should be best kept as part of the dts file.
Signed-off-by: NBenoit Parrot <bparrot@ti.com>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Fix attribute-creation race with userspace by using the default group
to create also the contingent gpio device attributes.

Fixes: d8f388d8 ("gpio: sysfs interface")
Signed-off-by: NJohan Hovold <johan@kernel.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>