aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/generic/files/include/linux/gpio_dev.h
diff options
context:
space:
mode:
authorFelix Fietkau <nbd@openwrt.org>2010-06-26 20:42:58 +0000
committerFelix Fietkau <nbd@openwrt.org>2010-06-26 20:42:58 +0000
commitda1bb88a2b900f0392b731ec47c5e1bff956fd8f (patch)
tree597146471e3eeafb4ba55e802e80b896770808ff /target/linux/generic/files/include/linux/gpio_dev.h
parent6117c04c9416b295347fb45c37e430f01df1d0d9 (diff)
downloadupstream-da1bb88a2b900f0392b731ec47c5e1bff956fd8f.tar.gz
upstream-da1bb88a2b900f0392b731ec47c5e1bff956fd8f.tar.bz2
upstream-da1bb88a2b900f0392b731ec47c5e1bff956fd8f.zip
rename target/linux/generic-2.6 to generic
SVN-Revision: 21952
Diffstat (limited to 'target/linux/generic/files/include/linux/gpio_dev.h')
-rw-r--r--target/linux/generic/files/include/linux/gpio_dev.h42
1 files changed, 42 insertions, 0 deletions
diff --git a/target/linux/generic/files/include/linux/gpio_dev.h b/target/linux/generic/files/include/linux/gpio_dev.h
new file mode 100644
index 0000000000..a2a4b51c78
--- /dev/null
+++ b/target/linux/generic/files/include/linux/gpio_dev.h
@@ -0,0 +1,42 @@
+#ifndef _GPIO_DEV_H__
+#define _GPIO_DEV_H__
+
+/*********************************************************************
+ *
+ * This Linux kernel header is expanded from the original driver
+ * (gpio_dev) by John Crispin. It provides an ioctl based interface to
+ * GPIO pins via the /dev/gpio char device and gpiolib within the kernel.
+ * The third argument to each ioctl is the GPIO pin number.
+ *
+ * This driver has been tested with lk 2.6.31 and works. The original
+ * driver fails quietly with this version. The protocol is now a bit
+ * different: the ioctl(fd, GPIO_REQUEST, <pin>) should be called
+ * after the open("/dev/gpio", O_RDWR) to determine if the <pin> is
+ * already in use. If the ioctl is successful (i.e. returns 0 for not
+ * in use) then the <pin> is claimed by this driver and
+ * ioctl(fd, GPIO_FREE, <pin>) should be called prior to close(fd) .
+ *
+ * See <kernel_source>/Documentation/gpio.txt
+ * Note that kernel designers prefer the use of the sysfs gpio interface.
+ * This char driver is easier to use from code and faster.
+ ********************************************************************/
+
+/* This header can be included in both the user and kernel spaces */
+/* The _IO macro is defined in sys/ioctl.h */
+
+#define IOC_GPIODEV_MAGIC 'B'
+
+#define GPIO_GET _IO(IOC_GPIODEV_MAGIC, 10)
+#define GPIO_SET _IO(IOC_GPIODEV_MAGIC, 11)
+#define GPIO_CLEAR _IO(IOC_GPIODEV_MAGIC, 12)
+#define GPIO_DIR_IN _IO(IOC_GPIODEV_MAGIC, 13)
+#define GPIO_DIR_OUT _IO(IOC_GPIODEV_MAGIC, 14)
+ /* Sets the direction out and clears the <pin> (low) */
+
+#define GPIO_DIR_HIGH _IO(IOC_GPIODEV_MAGIC, 15)
+ /* Sets the direction out and sets the <pin> (high) */
+#define GPIO_REQUEST _IO(IOC_GPIODEV_MAGIC, 16)
+#define GPIO_FREE _IO(IOC_GPIODEV_MAGIC, 17)
+#define GPIO_CAN_SLEEP _IO(IOC_GPIODEV_MAGIC, 18)
+
+#endif