myled_driver.c

arm at91sam9261 led 驱动

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <asm/uaccess.h>
#include <asm/arch/io.h>
#include <asm/arch/gpio.h>
#define NAME "myfourled"
static int major =231;
static unsigned long led_table [] =
{
    AT91_PIN_PA21,
    AT91_PIN_PA22,
    AT91_PIN_PA26,
    AT91_PIN_PA24,
};
static int myled_driver_ioctl(struct inode *inode,struct file *file,unsigned int cmd,unsigned long arg)
{
      unsigned int regled1;
      regled1=gpio_get_value(led_table[arg]);
      printk("led1 reg is : %d",regled1);
      at91_set_gpio_output(led_table[arg],1);
    switch(cmd)
    {
        case    0x00:at91_set_gpio_value(led_table[arg],0);
    		break;     
        case    0x01:gpio_set_value(led_table[arg],1);
   		 break;
        default:break;   
    }
    return 1;
}
static int myled_driver_open(struct inode *inode,struct file *file)
{
    unsigned m =iminor(inode);
    if(m>63) return -EINVAL;
    printk("led test driver opened!\n");
    return nonseekable_open(inode,file);
}
static int myled_driver_release(struct inode *inode,struct file *file)
{
    printk("my test driver released!\n");
    return 0;
}
static struct file_operations myled_driver_fops = 
{
    .owner =THIS_MODULE,
    .ioctl =myled_driver_ioctl,
    .open =myled_driver_open,
    .release =myled_driver_release,
};

static int __init myled_driver_init(void) //执行insmod的时候调用次函数
{
       int ret;   
       gpio_set_value(led_table[0],0);
       gpio_set_value(led_table[1],0);
       gpio_set_value(led_table[2],0);
       gpio_set_value(led_table[3],0);
       printk(KERN_ALERT "led modules is install\n");
       ret=register_chrdev(major,NAME,&myled_driver_fops);
        if(ret<0)
         {
              printk("unable to register myled driver!\n");
             return ret;
         }           
        return 0;
}

static void __exit myled_driver_exit(void)//执行rmmod的时候调用次函数
{
       unregister_chrdev(major,NAME);
}
module_init(myled_driver_init);
module_exit(myled_driver_exit);
MODULE_AUTHOR("lxs(www.emtronix.com)");
MODULE_DESCRIPTION("this is test modules used to test at91sam9261 led");
MODULE_LICENSE("Dual BSD/GPL");