| 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 |
| 43 | |
