#include < linux / fs.h >
//#include <linux/iobuf.h>
#include <linux/major.h>
#include <linux/blkdev.h>
#include <linux/capability.h>
#include <linux/smp_lock.h>
#include <asm/uaccess.h>
#include <asm/hardware.h>
#include <asm/arch/AT91RM9200.h>
#include <linux/vmalloc.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/config.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/ioport.h>
#include <linux/sched.h>
#include <asm/io.h>
#include <asm/arch/gpio.h>
#include <linux/delay.h>
MODULE_LICENSE(" GPL");
#define IOPORT_MAJOR 220 //定义主设备号
typedef char ioport_device_t;
static ioport_device_t gpio_devices[257];
#define IOWRITE1;
#define IOCLEAR2;
static intgpio_open(struct inode *inode, struct file *filp)
{
    int minor;
    minor = MINOR(inode->i_rdev);
    at91_set_gpio_output(AT91_PIN_PB3, 0);
    gpio_devices[minor]++;
    return 0;
}
static intgpio_release(struct inode *inode, struct file *filp)
{
    int minor;
    minor = MINOR(inode->i_rdev);
    if (gpio_devices[minor]) {
        gpio_devices[minor]--;
    }
    return 0;
}
static intgpio_ctl_ioctl(struct inode *inode, struct file *filp,
                         unsigned int command, unsigned long arg)
{
    int err = 0;
    int minor = MINOR(inode->i_rdev);
    switch (command) {
    case IOWRITE:
        err = at91_set_gpio_value(AT91_PIN_PB3, 1); //输出1高电平
        break;
    case IOCLEAR:
        err = at91_set_gpio_value(AT91_PIN_PB3, 0); //输出0低电平
        break;
    }
    return err;
}
static struct file_operations gpio_ctl_fops = {
owner:
    THIS_MODULE,
ioctl:
    gpio_ctl_ioctl,
open:
    gpio_open,
release:
    gpio_release,
};
static int __init gpio_init(void)
{
    register_chrdev(IOPORT_MAJOR, " gpiotest & quot;, & gpio_ctl_fops);
                    return 0;
}
static void __exit gpio_exit(void)
{
    unregister_chrdev(IOPORT_MAJOR, " gpiotest & quot;);
                      return 0;
}
module_init(gpio_init);
module_exit(gpio_exit);
测试程序:
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#define DEVICE_GPIOTEST"/dev/gpiotest"
#define IOWRITE1;
#define IOCLEAR2;

int main()
{
    int fd;
    int val = -1;
    if ((fd = open(DEVICE_GPIOTEST, O_WRITE | O_NONBLOCK)) < 0) {
        perror(" can not open device & quot;);
               exit(1);
    }
    while (1) {
        printf(" 0: set, 1: clear, 2: quit; ");
        scanf(" % d & quot;, & val);
              if (val == 0)
              ioctl(fd, IOWRITE, 0);
              else if (val == 1)
                  ioctl(fd, IOCLEAR, 0);
            else if (val == 2) {
                close(fd);
                    exit(1);
                }
    }
}