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: Alexandre Courbot <acourbot@nvidia.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus 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: Alexandre Courbot <acourbot@nvidia.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus 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: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus 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: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus 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: Aaron Lu <aaron.lu@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Dan Carpenter's static code checker reports:
The patch 473ed7be0d: "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: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus 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: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus 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: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Linus 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: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus 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: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus 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: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus 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: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus 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: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Linus 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: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Linus 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: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus 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: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
It makes more sense to have these functions close to each other. No
functional changes.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Linus 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: Zhang Rui <rui.zhang@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Linus 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: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Commit 0d1c28a (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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus 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: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Linus 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: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Linus 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: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
