leddrv.c

来自「nano2410linux的led驱动」· C语言 代码 · 共 82 行

#include<linux/config.h>
#include<linux/module.h>
#include<linux/kernel.h>
#include<linux/init.h>

#include<linux/miscdevice.h>
#include<linux/sched.h>
#include<linux/delay.h>
#include<linux/poll.h>
#include<linux/spinlock.h>
#include<linux/irq.h>

#include<asm/mach-types.h>
#include<asm/hardware.h>

#define DEVICE_NAME "ledtest" /*定义led设备名字*/
#define LED_MAJOR 230         /*定义led设备主设备号*/

//适用于2.4与2.6内核的模块许可证声明模板
MODULE_LICENSE("GPL");
/*LED设备对应的硬件资源*/
static unsigned long led_table[]={
  GPIO_G2,
  GPIO_E13,
  GPIO_E12,
  GPIO_E11,  
};

/*设备文件操作函数的实现*/
static int nano2410av2_leds_ioctl(struct inode * inode,struct file * filp,unsigned int cmd,unsigned long arg){
  switch(cmd){
   case 0:
   case 1:
    if(arg>4){
      return -EINVAL;
           }
    write_gpio_bit(led_table[arg],!cmd);
   default:
    return -EINVAL;           
     }
}

static struct file_operations nano2410av2_leds_fops={
    owner:THIS_MODULE,
    ioctl:nano2410av2_leds_ioctl,
};


/*模块初始化*/
static devfs_handle_t devfs_handle;
static int __init nano2410av2_leds_init(void){
  int ret;
  int i;
  /*在内核注册设备*/
  ret=register_chrdev(LED_MAJOR,DEVICE_NAME,&nano2410av2_leds_fops);
  if(ret<0){
   printk(DEVICE_NAME"can`t register major number\n");
   return ret;
     }

  //devfs_handle=devfs_register()
  	devfs_handle = devfs_register(NULL, DEVICE_NAME, DEVFS_FL_DEFAULT,
				LED_MAJOR, 0, S_IFCHR | S_IRUSR | S_IWUSR, &nano2410av2_leds_fops, NULL);
  for(i=0;i<8;i++){
       set_gpio_ctrl(led_table[i] | GPIO_PULLUP_EN | GPIO_MODE_OUT);                 
       write_gpio_bit(led_table[i],1);
     }
  printk(DEVICE_NAME"initialized\n");
  return 0;
}

static void __exit nano2410av2_leds_exit(void){
  //devfs_unregister(devfs_handle);
  devfs_unregister(devfs_handle);
   unregister_chrdev(LED_MAJOR,DEVICE_NAME);
   printk(DEVICE_NAME"removed\n");   //不用devfs注册时不会执行该句！
}

module_init(nano2410av2_leds_init);
module_exit(nano2410av2_leds_exit);