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authorMika Westerberg <mika.westerberg@linux.intel.com>2015-05-06 12:29:06 +0200
committerLinus Walleij <linus.walleij@linaro.org>2015-05-11 11:56:11 +0200
commitc884fbd452147e952ae160e750553d00ea4dc4c9 (patch)
tree7e2488cb40d3b70ac525fd3ea9ca2b69eda0c3f2 /drivers/gpio/gpiolib-acpi.c
parentgpio: mxc: read output value from GPIO_DR register (diff)
downloadlinux-c884fbd452147e952ae160e750553d00ea4dc4c9.tar.xz
linux-c884fbd452147e952ae160e750553d00ea4dc4c9.zip
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>
Diffstat (limited to 'drivers/gpio/gpiolib-acpi.c')
-rw-r--r--drivers/gpio/gpiolib-acpi.c29
1 files changed, 29 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index d2303d50f561..bff29bb0a3fe 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -514,6 +514,35 @@ struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
return lookup.desc ? lookup.desc : ERR_PTR(-ENOENT);
}
+/**
+ * acpi_dev_gpio_irq_get() - Find GpioInt and translate it to Linux IRQ number
+ * @adev: pointer to a ACPI device to get IRQ from
+ * @index: index of GpioInt resource (starting from %0)
+ *
+ * If the device has one or more GpioInt resources, this function can be
+ * used to translate from the GPIO offset in the resource to the Linux IRQ
+ * number.
+ *
+ * Return: Linux IRQ number (>%0) on success, negative errno on failure.
+ */
+int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index)
+{
+ int idx, i;
+
+ for (i = 0, idx = 0; idx <= index; i++) {
+ struct acpi_gpio_info info;
+ struct gpio_desc *desc;
+
+ desc = acpi_get_gpiod_by_index(adev, NULL, i, &info);
+ if (IS_ERR(desc))
+ break;
+ if (info.gpioint && idx++ == index)
+ return gpiod_to_irq(desc);
+ }
+ return -ENOENT;
+}
+EXPORT_SYMBOL_GPL(acpi_dev_gpio_irq_get);
+
static acpi_status
acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address,
u32 bits, u64 *value, void *handler_context,