[PATCH] gpiolib: add gpio_request/free_irq

[H Hartley Sweeten <hartleys@visionengravers.com>]

Add support functions to gpiolib to request/free gpio irqs.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>

---

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 51a8d41..5b4b864 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1103,6 +1103,52 @@ int __gpio_to_irq(unsigned gpio)
 }
 EXPORT_SYMBOL_GPL(__gpio_to_irq);
 
+/**
+ * gpio_request_irq() - allocate a gpio interrupt line
+ * @gpio: gpio whose IRQ will be allocated
+ * @handler: function to be called when the IRQ occurs
+ * @irqflags: interrupt type flags
+ * @label: an ascii name for the claiming device
+ * @data: a cookie passed back to the handling function
+ */
+int gpio_request_irq(unsigned gpio, irq_handler_t handler,
+			unsigned long irqflags, const char *label, void *data)
+{
+	int err;
+
+	err = gpio_request(gpio, label);
+	if (err)
+		goto fail;
+
+	err = gpio_direction_input(gpio);
+	if (err)
+		goto free;
+
+	err = request_irq(gpio_to_irq(gpio), handler, irqflags, label, data);
+	if (err)
+		goto free;
+
+	return 0;
+
+free:
+	gpio_free(gpio);
+fail:
+	return err;
+}
+EXPORT_SYMBOL_GPL(gpio_request_irq);
+
+/**
+ * gpio_free_irq() - free an interrupt allocated with gpio_request_irq
+ * @irq: gpio interrupt line to free
+ * @data: device identity to free
+ */
+void gpio_free_irq(unsigned int irq, void *data)
+{
+	free_irq(irq, data);
+	gpio_free(irq_to_gpio(irq));
+}
+EXPORT_SYMBOL_GPL(gpio_free_irq);
+
 
 
 /* There's no value in making it easy to inline GPIO calls that may sleep.
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index d6c379d..c0ab7cf 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -3,6 +3,7 @@
 
 #include <linux/types.h>
 #include <linux/errno.h>
+#include <linux/interrupt.h>
 
 #ifdef CONFIG_GPIOLIB
 
@@ -134,6 +135,11 @@ extern int __gpio_cansleep(unsigned gpio);
 
 extern int __gpio_to_irq(unsigned gpio);
 
+/* request/free gpio interrupt */
+extern int gpio_request_irq(unsigned gpio, irq_handler_t handler,
+			unsigned long irqflags, const char *label, void *data);
+extern void gpio_free_irq(unsigned int irq, void *data);
+
 #ifdef CONFIG_GPIO_SYSFS
 
 /*
diff --git a/include/linux/gpio.h b/include/linux/gpio.h
index e10c49a..eaf7b27 100644
--- a/include/linux/gpio.h
+++ b/include/linux/gpio.h
@@ -109,6 +109,18 @@ static inline int irq_to_gpio(unsigned irq)
 	return -EINVAL;
 }
 
+static inline int gpio_request_irq(unsigned gpio, irq_handler_t handler,
+			unsigned long irqflags, const char *label, void *data)
+{
+	return -ENOSYS;
+}
+
+static inline void gpio_free_irq(unsigned int irq, void *data)
+{
+	/* GPIO irq can never have been requested */
+	WARN_ON(1);
+}
+
 #endif
 
 #endif /* __LINUX_GPIO_H */