The size_prop argument of the recently added function
acpi_dev_get_property_reference() is not used by the only current
caller of that function and is very unlikely to be used at any time
going forward.

Namely, for a property whose value is a list of items each containing
a references to a device object possibly accompanied by some integers,
the number of items in the list can always be computed as the number
of elements of type ACPI_TYPE_LOCAL_REFERENCE in the property package.
Thus it should never be necessary to provide an additional "cells"
property with a value equal to the number of items in that list.  It
also should never be necessary to provide a "cells" property specifying
how many integers are supposed to be following each reference.

For this reason, drop the size_prop argument from
acpi_dev_get_property_reference() and update its caller accordingly.

Link: http://marc.info/?l=linux-kernel&m=141511255610556&w=2Suggested-by: NGrant Likely <grant.likely@linaro.org>
Acked-by: NGrant Likely <grant.likely@linaro.org>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Provide a way for device drivers using GPIOs described by ACPI
GpioIo resources in _CRS to tell the GPIO subsystem what names
(connection IDs) to associate with specific GPIO pins defined
in there.

To do that, a driver needs to define a mapping table as a
NULL-terminated array of struct acpi_gpio_mapping objects
that each contain a name, a pointer to an array of line data
(struct acpi_gpio_params) objects and the size of that array.

Each struct acpi_gpio_params object consists of three fields,
crs_entry_index, line_index, active_low, representing the index of
the target GpioIo()/GpioInt() resource in _CRS starting from zero,
the index of the target line in that resource starting from zero,
and the active-low flag for that line, respectively.

Next, the mapping table needs to be passed as the second
argument to acpi_dev_add_driver_gpios() that will register it with
the ACPI device object pointed to by its first argument.  That
should be done in the driver's .probe() routine.

On removal, the driver should unregister its GPIO mapping table
by calling acpi_dev_remove_driver_gpios() on the ACPI device
object where that table was previously registered.

Included are fixes from Mika Westerberg.
Acked-by: NAlexandre Courbot <acourbot@nvidia.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

With release of ACPI 5.1 and _DSD method we can finally name GPIOs (and
other things as well) returned by _CRS. Previously we were only able to
use integer index to find the corresponding GPIO, which is pretty error
prone if the order changes.

With _DSD we can now query GPIOs using name instead of an integer index,
like the below example shows:

  // Bluetooth device with reset and shutdown GPIOs
  Device (BTH)
  {
      Name (_HID, ...)

      Name (_CRS, ResourceTemplate ()
      {
          GpioIo (Exclusive, PullUp, 0, 0, IoRestrictionInputOnly,
                  "\\_SB.GPO0", 0, ResourceConsumer) {15}
          GpioIo (Exclusive, PullUp, 0, 0, IoRestrictionInputOnly,
                  "\\_SB.GPO0", 0, ResourceConsumer) {27, 31}
      })

      Name (_DSD, Package ()
      {
          ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
          Package ()
	  {
              Package () {"reset-gpio", Package() {^BTH, 1, 1, 0 }},
              Package () {"shutdown-gpio", Package() {^BTH, 0, 0, 0 }},
          }
      })
  }

The format of the supported GPIO property is:

  Package () { "name", Package () { ref, index, pin, active_low }}

  ref - The device that has _CRS containing GpioIo()/GpioInt() resources,
        typically this is the device itself (BTH in our case).
  index - Index of the GpioIo()/GpioInt() resource in _CRS starting from zero.
  pin - Pin in the GpioIo()/GpioInt() resource. Typically this is zero.
  active_low - If 1 the GPIO is marked as active_low.

Since ACPI GpioIo() resource does not have field saying whether it is
active low or high, the "active_low" argument can be used here. Setting
it to 1 marks the GPIO as active low.

In our Bluetooth example the "reset-gpio" refers to the second GpioIo()
resource, second pin in that resource with the GPIO number of 31.

This patch implements necessary support to gpiolib for extracting GPIOs
using _DSD device properties.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NGrant Likely <grant.likely@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The GPIO resources (GpioIo/GpioInt) used in ACPI contain a GPIO number
which is relative to the hardware GPIO controller. Typically this number
can be translated directly to Linux GPIO number because the mapping is
pretty much 1:1.

However, when the GPIO driver is using pins exported by a pin controller
driver via set of GPIO ranges, the mapping might not be 1:1 anymore and
direct translation does not work.

In such cases we need to translate the ACPI GPIO number to be suitable for
the GPIO controller driver in question by checking all the pin controller
GPIO ranges under the given device and using those to get the proper GPIO
number.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
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>

Fix code when the operation region callback is for an gpio, which
is not at index 0 and for partial pins in a GPIO definition.
For example:
Name (GMOD, ResourceTemplate ()
{
	//3 Outputs that define the Power mode of the device
	GpioIo (Exclusive, PullDown, , , , "\\_SB.GPI2") {10, 11, 12}
	})
}

If opregion callback calls is for:
- Set pin 10, then address = 0 and bit length = 1
- Set pin 11, then address = 1 and bit length = 1
- Set for both pin 11 and pin 12, then address = 1, bit length = 2

This change requires updated ACPICA gpio operation handler code to
send the pin index and bit length.

Fixes: 473ed7be (gpio / ACPI: Add support for ACPI GPIO operation regions)
Signed-off-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Cc: 3.15+ <stable@vger.kernel.org> # 3.15+: 75ec6e55 ACPICA: Update to GPIO region handler interface.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

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>

GPIO descriptors are changing from unique and permanent tokens to
allocated resources. Therefore gpiochip_get_desc() cannot be used as a
way to obtain a global GPIO descriptor anymore.

This patch updates the gpiolib ACPI support code to keep and use the
descriptor returned by a centralized call to gpiochip_get_desc().
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>

Since now we have irqchip helpers that the GPIO chip drivers are supposed
to use if possible, we can move the registration of ACPI events to happen
in these helpers. This seems to be more natural place and might encourage
GPIO chip driver writers to take advantage of the irqchip helpers.

We make the functions available to GPIO chip drivers via private gpiolib.h,
just in case generic irqchip helpers are not suitable.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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>

The GPIO operation region handler should be called where sleep is
allowed, so we should use the *_cansleep version of gpiod_get/set APIs
or we will get a warning message complaining invalid context if the GPIO
chip has the cansleep flag set.
Signed-off-by: NAaron Lu <aaron.lu@intel.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Dan Carpenter's static code checker reports:

 The patch 473ed7be: "gpio / ACPI: Add support for ACPI GPIO
 operation regions" from Mar 14, 2014, leads to the following static
 checker warning:

  drivers/gpio/gpiolib-acpi.c:454 acpi_gpio_adr_space_handler()
  warn: should 'gpiod_get_raw_value(desc) << i' be a 64 bit type?

This is due the fact that *value is of type u64 and gpiod_get_raw_value()
returns int. Since i can be larger than 31, it is possible that the value
returned gets wrapped.

Fix this by casting the return of gpiod_get_raw_value() to u64 first before
shift.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Commit aa92b6f6 (gpio / ACPI: Allocate ACPI specific data directly in
acpi_gpiochip_add()) moved ACPI handle checking to acpi_gpiochip_add() but
forgot to check whether chip->dev is NULL before dereferencing it.

Since chip->dev pointer is optional we can end up with crash like following:

 BUG: unable to handle kernel NULL pointer dereference at 00000138
 IP: [<c126c2b3>] acpi_gpiochip_add+0x13/0x190
 *pde = 00000000
 Oops: 0000 [#1] PREEMPT SMP
 Modules linked in: ssb(+) ...
 CPU: 0 PID: 512 Comm: modprobe Tainted: G        W     3.14.0-rc7-next-20140324-t1 #24
 Hardware name: Dell Inc. Latitude D830                   /0UY141, BIOS A02 06/07/2007
 task: f5799900 ti: f543e000 task.ti: f543e000
 EIP: 0060:[<c126c2b3>] EFLAGS: 00010282 CPU: 0
 EIP is at acpi_gpiochip_add+0x13/0x190
 EAX: 00000000 EBX: f57824c4 ECX: 00000000 EDX: 00000000
 ESI: f57824c4 EDI: 00000010 EBP: f543fc54 ESP: f543fc40
  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
 CR0: 8005003b CR2: 00000138 CR3: 355f8000 CR4: 000007d0
 Stack:
  f543fc5c fd1f7790 f57824c4 000000be 00000010 f543fc84 c1269f4e f543fc74
  fd1f78bd 00008002 f57822b0 f5782090 fd1f8400 00000286 fd1f9994 00000000
  f5782000 f543fc8c fd1f7e39 f543fcc8 fd1f0bd8 000000c0 00000000 00000000
 Call Trace:
  [<fd1f7790>] ? ssb_pcie_mdio_write+0xa0/0xd0 [ssb]
  [<c1269f4e>] gpiochip_add+0xee/0x300
  [<fd1f78bd>] ? ssb_pcicore_serdes_workaround+0xfd/0x140 [ssb]
  [<fd1f7e39>] ssb_gpio_init+0x89/0xa0 [ssb]
  [<fd1f0bd8>] ssb_attach_queued_buses+0xc8/0x2d0 [ssb]
  [<fd1f0f65>] ssb_bus_register+0x185/0x1f0 [ssb]
  [<fd1f3120>] ? ssb_pci_xtal+0x220/0x220 [ssb]
  [<fd1f106c>] ssb_bus_pcibus_register+0x2c/0x80 [ssb]
  [<fd1f40dc>] ssb_pcihost_probe+0x9c/0x110 [ssb]
  [<c1276c8f>] pci_device_probe+0x6f/0xc0
  [<c11bdb55>] ? sysfs_create_link+0x25/0x40
  [<c131d8b9>] driver_probe_device+0x79/0x360
  [<c1276512>] ? pci_match_device+0xb2/0xc0
  [<c131dc51>] __driver_attach+0x71/0x80
  [<c131dbe0>] ? __device_attach+0x40/0x40
  [<c131bd87>] bus_for_each_dev+0x47/0x80
  [<c131d3ae>] driver_attach+0x1e/0x20
  [<c131dbe0>] ? __device_attach+0x40/0x40
  [<c131d007>] bus_add_driver+0x157/0x230
  [<c131e219>] driver_register+0x59/0xe0
  ...

Fix this by checking chip->dev pointer against NULL first. Also we can now
remove redundant check in acpi_gpiochip_request/free_interrupts().
Reported-by: NSabrina Dubroca <sd@queasysnail.net>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: NSabrina Dubroca <sd@queasysnail.net>
Acked-by: NAlexandre Courbot <acourbot@nvidia.com>
Tested-by: NJosh Boyer <jwboyer@fedoraproject.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

GPIO operation regions is a new feature introduced in ACPI 5.0
specification. This feature adds a way for platform ASL code to call back
to OS GPIO driver and toggle GPIO pins.

An example ASL code from Lenovo Miix 2 tablet with only relevant part
listed:

 Device (\_SB.GPO0)
 {
     Name (AVBL, Zero)
     Method (_REG, 2, NotSerialized)
     {
         If (LEqual (Arg0, 0x08))
         {
             // Marks the region available
             Store (Arg1, AVBL)
         }
     }

     OperationRegion (GPOP, GeneralPurposeIo, Zero, 0x0C)
     Field (GPOP, ByteAcc, NoLock, Preserve)
     {
         Connection (
             GpioIo (Exclusive, PullDefault, 0, 0, IoRestrictionOutputOnly,
                     "\\_SB.GPO0", 0x00, ResourceConsumer,,)
             {
                 0x003B
             }
         ),
         SHD3,   1,
     }
 }

 Device (SHUB)
 {
     Method (_PS0, 0, Serialized)
     {
         If (LEqual (\_SB.GPO0.AVBL, One))
         {
             Store (One, \_SB.GPO0.SHD3)
             Sleep (0x32)
         }
     }
     Method (_PS3, 0, Serialized)
     {
         If (LEqual (\_SB.GPO0.AVBL, One))
         {
             Store (Zero, \_SB.GPO0.SHD3)
         }
     }
 }

How this works is that whenever _PS0 or _PS3 method is run (typically when
SHUB device is transitioned to D0 or D3 respectively), ASL code checks if
the GPIO operation region is available (\_SB.GPO0.AVBL). If it is we go and
store either 0 or 1 to \_SB.GPO0.SHD3.

Now, when ACPICA notices ACPI GPIO operation region access (the store
above) it will call acpi_gpio_adr_space_handler() that then toggles the
GPIO accordingly using standard gpiolib interfaces.

Implement the support by registering GPIO operation region handlers for all
GPIO devices that have an ACPI handle. First time the GPIO is used by the
ASL code we make sure that the GPIO stays requested until the GPIO chip
driver itself is unloaded. If we find out that the GPIO is already
requested we just toggle it according to the value got from ASL code.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The current ACPI GPIO event handling code was never tested against real
hardware with functioning GPIO triggered events (at the time such hardware
wasn't available). Thus it misses certain things like requesting the GPIOs
properly, passing correct flags to the interrupt handler and so on.

This patch reworks ACPI GPIO event handling so that we:

 1) Use struct acpi_gpio_event for all GPIO signaled events.
 2) Switch to use GPIO descriptor API and request GPIOs by calling
    gpiochip_request_own_desc() that we added in a previous patch.
 3) Pass proper flags from ACPI GPIO resource to request_threaded_irq().

Also instead of open-coding the _AEI iteration loop we can use
acpi_walk_resources(). This simplifies the code a bit and fixes memory leak
that was caused by missing kfree() for buffer returned by
acpi_get_event_resources().

Since the remove path now calls gpiochip_free_own_desc() which takes GPIO
spinlock we need to call acpi_gpiochip_remove() outside of that lock
(analogous to acpi_gpiochip_add() path where the lock is released before
those funtions are called).
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

In order to consolidate _Exx, _Lxx and _EVT to use the same structure make
the structure name to reflect that we are dealing with any event, not just
_EVT.

This is just rename, no functional changes.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

We are going to add more ACPI specific data to accompany GPIO chip so
instead of allocating it per each use-case we allocate it once when
acpi_gpiochip_add() is called and release it when acpi_gpiochip_remove() is
called.

Doing this allows us to add more ACPI specific data by merely adding new
fields to struct acpi_gpio_chip.

In addition we embed evt_pins member directly to the structure instead of
having it as a pointer. This simplifies the code a bit since we don't need
to check against NULL.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

gpio_to_desc() must die. Replace one of its usage by the
newly-introduced gpiochip_get_desc() function.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Now that all users of acpi_gpio.h have been moved to use either the GPIO
descriptor interface or to the internal gpiolib.h we can get rid of
acpi_gpio.h entirely.

Once this is done the only interface to get GPIOs to drivers enumerated
from ACPI namespace is the descriptor based interface.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Instead of asking each driver to register to ACPI events we can just call
acpi_gpiochip_register_interrupts() for each chip that has an ACPI handle.
The function checks chip->to_irq and if it is set to NULL (a GPIO driver
that doesn't do interrupts) the function does nothing.

We also add the a new header drivers/gpio/gpiolib.h that is used for
functions internal to gpiolib and add ACPI GPIO chip registering functions
to that header.

Once that is done we can remove call to acpi_gpiochip_register_interrupts()
from its only user, pinctrl-baytrail.c
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Doing this allows drivers to distinguish between a real error case (if
there was an error when we tried to resolve the GPIO) and when the optional
GPIO line was not available.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NAlexandre Courbot <acourbot@nvidia.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

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>

The new GPIO descriptor based interface is now preferred over the old
integer based one. This patch converts the ACPI GPIO helpers to use this
new interface internally. In addition to that provide compatibility
function acpi_get_gpio_by_index() that converts the returned GPIO
descriptor to an integer.

We also drop acpi_get_gpio() as it is not used anywhere outside
gpiolib-acpi and even there we use acpi_get_gpiod() instead.
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>

It makes more sense to have these functions close to each other. No
functional changes.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

acpi_execute_simple_method() is a new ACPI API introduced to invoke
an ACPI control method that has single integer parameter and no return value.

Convert acpi_evaluate_object() to acpi_execute_simple_method()
in drivers/gpio/gpiolib-acpi.c
Signed-off-by: NZhang Rui <rui.zhang@intel.com>
CC: Linus Walleij <linus.walleij@linaro.org>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

acpi_execute_simple_method() is a new ACPI API introduced to invoke
an ACPI control method that has single integer parameter and no return value.

Convert acpi_evaluate_object() to acpi_execute_simple_method()
in drivers/gpio/gpiolib-acpi.c
Signed-off-by: NZhang Rui <rui.zhang@intel.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Instead of open-coding ACPI GPIO resource lookup in each driver, we provide
a helper function analogous to Device Tree version that allows drivers to
specify which GPIO resource they are interested (using an index to the GPIO
resources). The function then finds out the correct resource, translates
the ACPI GPIO number to the corresponding Linux GPIO number and returns
that.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Commit 0d1c28a4 (gpiolib-acpi: Add ACPI5 event model support to gpio.)
that added support for ACPI events signalled through GPIO interrupts
covered only GPIO pins whose numbers are less than or equal to 255.
However, there may be GPIO pins with numbers greater than 255 and
the ACPI spec (ACPI 5.0, Section 5.6.5.1) requires the _EVT method
to be used for handling events corresponding to those pins.

Moreover, according to the spec, _EVT is the default mechanism
for handling all ACPI events signalled through GPIO interrupts,
so if the _Exx/_Lxx method is not present for the given pin,
_EVT should be used instead.  If present, though, _Exx/_Lxx take
precedence over _EVT which shouldn't be executed in that case
(ACPI 5.0, Section 5.6.5.3).

Modify acpi_gpiochip_request_interrupts() to follow the spec as
described above and add acpi_gpiochip_free_interrupts() needed
to free interrupts associated with _EVT.
Signed-off-by: NRafael 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>

Print error message if requesting an interrupt fails.
Use int instead of unsigned for interrupts in case of error values
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add ability to handle ACPI events signalled by GPIO interrupts.

ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
handled by ACPI event methods which need to be called from the GPIO
controller's interrupt handler. acpi_gpio_request_interrupt() finds out which
gpio pins have acpi event methods and assigns interrupt handlers that calls
the acpi event methods for those pins.

Partially based on work by Rui Zhang <rui.zhang@intel.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add support for translating ACPI GPIO pin numbers to Linux GPIO API pins.
Needs a gpio controller driver with the acpi handler hook set.

Drivers can use acpi_get_gpio() to translate ACPI5 GpioIO and GpioInt
resources to Linux GPIO's.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>