gpio / ACPI: Add support for retrieving GpioInt resources from a device
authorMika Westerberg <mika.westerberg@linux.intel.com>
Wed, 6 May 2015 10:29:06 +0000 (13:29 +0300)
committerLinus Walleij <linus.walleij@linaro.org>
Mon, 11 May 2015 09:56:11 +0000 (11:56 +0200)
commitc884fbd452147e952ae160e750553d00ea4dc4c9
tree7e2488cb40d3b70ac525fd3ea9ca2b69eda0c3f2
parent442b2494b17d1a4f0a14721580271eb23ebffd42
gpio / ACPI: Add support for retrieving GpioInt resources from a device

ACPI specification knows two types of GPIOs: GpioIo and GpioInt. The latter
is used to describe that a given device interrupt line is connected to a
specific GPIO pin. Typical ACPI _CRS entry for such device looks like
below:

    Name (_CRS, ResourceTemplate ()
    {
        I2cSerialBus (0x004A, ControllerInitiated, 0x00061A80,
                      AddressingMode7Bit, "\\_SB.PCI0.I2C6",
                      0x00, ResourceConsumer)
        GpioIo (Exclusive, PullDefault, 0x0000, 0x0000,
                IoRestrictionOutputOnly, "\\_SB.GPO0",
                0x00, ResourceConsumer)
        {
            0x004B
        }
        GpioInt (Level, ActiveLow, Shared, PullDefault, 0x0000,
                 "\\_SB.GPO0", 0x00, ResourceConsumer)
        {
            0x004C
        }
    })

Currently drivers need to request a GPIO corresponding to the right GpioInt
and then translate that to Linux IRQ number. This adds unnecessary lines of
boiler-plate code.

We can ease this a bit by introducing acpi_dev_gpio_irq_get() analogous to
of_irq_get(). This function translates given GpioInt resource under the
device in question to the suitable Linux IRQ number.

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>
drivers/gpio/gpiolib-acpi.c
include/linux/acpi.h