gpio: introduce gpio_request_one() and friends
gpio_request() without initial configuration of the GPIO is normally
useless, introduce gpio_request_one() together with GPIOF_ flags for
input/output direction and initial output level.
gpio_{request,free}_array() for multiple GPIOs.
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Ben Nizette <bn@niasdigital.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index 485eeb6..979c6a5 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -136,6 +136,32 @@
extern int __gpio_to_irq(unsigned gpio);
+#define GPIOF_DIR_OUT (0 << 0)
+#define GPIOF_DIR_IN (1 << 0)
+
+#define GPIOF_INIT_LOW (0 << 1)
+#define GPIOF_INIT_HIGH (1 << 1)
+
+#define GPIOF_IN (GPIOF_DIR_IN)
+#define GPIOF_OUT_INIT_LOW (GPIOF_DIR_OUT | GPIOF_INIT_LOW)
+#define GPIOF_OUT_INIT_HIGH (GPIOF_DIR_OUT | GPIOF_INIT_HIGH)
+
+/**
+ * struct gpio - a structure describing a GPIO with configuration
+ * @gpio: the GPIO number
+ * @flags: GPIO configuration as specified by GPIOF_*
+ * @label: a literal description string of this GPIO
+ */
+struct gpio {
+ unsigned gpio;
+ unsigned long flags;
+ const char *label;
+};
+
+extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
+extern int gpio_request_array(struct gpio *array, size_t num);
+extern void gpio_free_array(struct gpio *array, size_t num);
+
#ifdef CONFIG_GPIO_SYSFS
/*