Commit Graph

4 Commits

Author SHA1 Message Date
Mika Westerberg 12028d2d21 gpiolib-acpi: introduce acpi_get_gpio_by_index() helper
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>
2013-04-12 00:31:18 +02:00
Rafael J. Wysocki 7fc7acb9a0 gpio / ACPI: Handle ACPI events in accordance with the spec
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>
2013-04-10 23:41:17 +02:00
Mathias Nyman 0d1c28a449 gpiolib-acpi: Add ACPI5 event model support to gpio.
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>
2013-01-29 11:47:06 +01:00
Mathias Nyman e29482e848 gpio / ACPI: add ACPI support
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>
2012-11-30 12:37:36 +01:00