target/linux/generic/files/include/linux/gpio_dev.h

   1 #ifndef _GPIO_DEV_H__
   2 #define _GPIO_DEV_H__
   3
   4 /*********************************************************************
   5  *
   6  * This Linux kernel header is expanded from the original driver
   7  * (gpio_dev) by John Crispin. It provides an ioctl based interface to
   8  * GPIO pins via the /dev/gpio char device and gpiolib within the kernel.
   9  * The third argument to each ioctl is the GPIO pin number.
  10  *
  11  * This driver has been tested with lk 2.6.31 and works. The original
  12  * driver fails quietly with this version. The protocol is now a bit
  13  * different: the ioctl(fd, GPIO_REQUEST, <pin>) should be called
  14  * after the open("/dev/gpio", O_RDWR) to determine if the <pin> is
  15  * already in use. If the ioctl is successful (i.e. returns 0 for not
  16  * in use) then the <pin> is claimed by this driver and
  17  * ioctl(fd, GPIO_FREE, <pin>) should be called prior to close(fd) .
  18  *
  19  * See <kernel_source>/Documentation/gpio.txt
  20  * Note that kernel designers prefer the use of the sysfs gpio interface.
  21  * This char driver is easier to use from code and faster.
  22  ********************************************************************/
  23
  24 /* This header can be included in both the user and kernel spaces */
  25 /* The _IO macro is defined in sys/ioctl.h */
  26
  27 #define IOC_GPIODEV_MAGIC  'B'
  28
  29 #define GPIO_GET        _IO(IOC_GPIODEV_MAGIC, 10)
  30 #define GPIO_SET        _IO(IOC_GPIODEV_MAGIC, 11)
  31 #define GPIO_CLEAR      _IO(IOC_GPIODEV_MAGIC, 12)
  32 #define GPIO_DIR_IN     _IO(IOC_GPIODEV_MAGIC, 13)
  33 #define GPIO_DIR_OUT    _IO(IOC_GPIODEV_MAGIC, 14)
  34         /* Sets the direction out and clears the <pin> (low) */
  35
  36 #define GPIO_DIR_HIGH   _IO(IOC_GPIODEV_MAGIC, 15)
  37         /* Sets the direction out and sets the <pin> (high) */
  38 #define GPIO_REQUEST    _IO(IOC_GPIODEV_MAGIC, 16)
  39 #define GPIO_FREE       _IO(IOC_GPIODEV_MAGIC, 17)
  40 #define GPIO_CAN_SLEEP  _IO(IOC_GPIODEV_MAGIC, 18)
  41
  42 #endif