[PATCH v2 4/5] gpiolib / ACPI: allow passing GPIOF_ACTIVE_LOW for GpioInt resources

[Mika Westerberg <mika.westerberg@linux.intel.com>]

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>
---
 drivers/gpio/gpiolib-acpi.c |  2 ++
 drivers/gpio/gpiolib.c      | 12 +++++++++++-
 include/linux/acpi_gpio.h   |  2 ++
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index 03187d0..ae0ffdc 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -253,6 +253,8 @@ static int acpi_find_gpio(struct acpi_resource *ares, void *data)
 					      agpio->pin_table[0]);
 		lookup->info.gpioint =
 			agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
+		lookup->info.active_low =
+			agpio->polarity == ACPI_ACTIVE_LOW;
 	}
 
 	return 1;
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 1e099de..b01a231 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2115,7 +2115,17 @@ static struct gpio_desc *of_find_gpio(struct device *dev, const char *id,
 static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id,
 					unsigned int idx, unsigned long *flags)
 {
-	return acpi_get_gpiod_by_index(dev, idx, NULL);
+	struct acpi_gpio_info info;
+	struct gpio_desc *desc;
+
+	desc = acpi_get_gpiod_by_index(dev, idx, &info);
+	if (IS_ERR(desc))
+		return desc;
+
+	if (info.gpioint && info.active_low)
+		*flags |= GPIOF_ACTIVE_LOW;
+
+	return desc;
 }
 
 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
diff --git a/include/linux/acpi_gpio.h b/include/linux/acpi_gpio.h
index b6ce601..d875bc3 100644
--- a/include/linux/acpi_gpio.h
+++ b/include/linux/acpi_gpio.h
@@ -10,9 +10,11 @@
 /**
  * struct acpi_gpio_info - ACPI GPIO specific information
  * @gpioint: if %true this GPIO is of type GpioInt otherwise type is GpioIo
+ * @active_low: in case of @gpioint, the pin is active low
  */
 struct acpi_gpio_info {
 	bool gpioint;
+	bool active_low;
 };
 
 #ifdef CONFIG_GPIO_ACPI
-- 
1.8.4.rc3