led.c

简单程序

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/poll.h>
#include <linux/spinlock.h>
#include <linux/irq.h>
#include <asm-arm/hardware.h>

#define DEVICE_NAME "led"
#define LED_MAJOR 231

static unsigned long led_table[]={GPIO_B0,GPIO_B1,GPIO_B2,GPIO_B3};

static int led_ioctl(struct inode *inode,struct file *file,unsigned int cmd,unsigned long arg)
{
  write_gpio_bit(led_table[arg],!cmd);
  return -EINVAL;
}

static struct file_operations led_fops={ owner:THIS_MODULE,ioctl:led_ioctl};
static devfs_handle_t devfs_handle;

static int __init led_int(void)
{
  int ret;
  int i;
  ret=register_chrdev(LED_MAJOR,DEVICE_NAME,&led_fops);
  if(ret<0)
  {
    printk(DEVICE_NAME"can't register major  number\n");
    return ret;
  }

 devfs_handle=devfs_register(NULL,DEVICE_NAME,DEVFS_FL_DEFAULT,LED_MAJOR,0,S_IFCHR|S_IRUSR|S_IWUSR,&led_fops,NULL);
 for(i=0;i<4;i++)
 {
   set_gpio_ctrl(led_table[i]|GPIO_PULLUP_EN|GPIO_MODE_OUT);
   write_gpio_bit(led_table[i],1);
 }
 printk(DEVICE_NAME"is initialized!Made by fsgu\n");
 return 0;
}

static void __exit led_exit(void)
{
  devfs_unregister(devfs_handle);
  unregister_chrdev(LED_MAJOR,DEVICE_NAME);
  printk(DEVICE_NAME" is uninstalled! Made by fsgu\n");
}

module_init(led_int);
module_exit(led_exit);