1 files changed, 87 insertions, 0 deletions

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index cbad6e908d3..a063eb04b6c 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -15,6 +15,7 @@
 #include <linux/export.h>
 #include <linux/acpi_gpio.h>
 #include <linux/acpi.h>
+#include <linux/interrupt.h>
 
 static int acpi_gpiochip_find(struct gpio_chip *gc, void *data)
 {
@@ -52,3 +53,89 @@ int acpi_get_gpio(char *path, int pin)
 	return chip->base + pin;
 }
 EXPORT_SYMBOL_GPL(acpi_get_gpio);
+
+
+static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
+{
+	acpi_handle handle = data;
+
+	acpi_evaluate_object(handle, NULL, NULL, NULL);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
+ * @chip:      gpio chip
+ *
+ * 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
+ * chip's interrupt handler. acpi_gpiochip_request_interrupts finds out which
+ * gpio pins have acpi event methods and assigns interrupt handlers that calls
+ * the acpi event methods for those pins.
+ *
+ * Interrupts are automatically freed on driver detach
+ */
+
+void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
+{
+	struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
+	struct acpi_resource *res;
+	acpi_handle handle, ev_handle;
+	acpi_status status;
+	unsigned int pin;
+	int irq, ret;
+	char ev_name[5];
+
+	if (!chip->dev || !chip->to_irq)
+		return;
+
+	handle = ACPI_HANDLE(chip->dev);
+	if (!handle)
+		return;
+
+	status = acpi_get_event_resources(handle, &buf);
+	if (ACPI_FAILURE(status))
+		return;
+
+	/* If a gpio interrupt has an acpi event handler method, then
+	 * set up an interrupt handler that calls the acpi event handler
+	 */
+
+	for (res = buf.pointer;
+	     res && (res->type != ACPI_RESOURCE_TYPE_END_TAG);
+	     res = ACPI_NEXT_RESOURCE(res)) {
+
+		if (res->type != ACPI_RESOURCE_TYPE_GPIO ||
+		    res->data.gpio.connection_type !=
+		    ACPI_RESOURCE_GPIO_TYPE_INT)
+			continue;
+
+		pin = res->data.gpio.pin_table[0];
+		if (pin > chip->ngpio)
+			continue;
+
+		sprintf(ev_name, "_%c%02X",
+		res->data.gpio.triggering ? 'E' : 'L', pin);
+
+		status = acpi_get_handle(handle, ev_name, &ev_handle);
+		if (ACPI_FAILURE(status))
+			continue;
+
+		irq = chip->to_irq(chip, pin);
+		if (irq < 0)
+			continue;
+
+		/* Assume BIOS sets the triggering, so no flags */
+		ret = devm_request_threaded_irq(chip->dev, irq, NULL,
+					  acpi_gpio_irq_handler,
+					  0,
+					  "GPIO-signaled-ACPI-event",
+					  ev_handle);
+		if (ret)
+			dev_err(chip->dev,
+				"Failed to request IRQ %d ACPI event handler\n",
+				irq);
+	}
+}
+EXPORT_SYMBOL(acpi_gpiochip_request_interrupts);