linux驱动之led闪烁

/*************************LED驱动*************************/

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/slab.h>
#include <linux/gpio.h>
#include <plat/gpio-cfg.h>
#include <asm/uaccess.h>
#include <asm/io.h>


#define PA_GPC0CON 0xE0200060//LED 寄存器的基地址

volatile unsigned int *GPC0CON;
volatile unsigned int *GPC0DAT;

//设计设备对象
struct s5p210_led{
    struct cdev *c_dev;//cdev结构体描述一个字符设备
    struct class *cls;//设备结点类结构体
    struct device *dev;//设备属性结构体
    dev_t devno;//设备节点
};

static struct s5p210_led *led_dev;
static int ret = -1;

int led_open(struct inode *inode, struct file *filp)
{//实现硬件的初始化

#if 0
    //GPIO配置为输出
    *GPC0CON &= ~(0xFF<<12);
    *GPC0CON |= (0x11<<12);
    //LED输出为低
    *GPC0DAT &= ~0x18;
    printk(KERN_INFO"----%s--------\n", __FUNCTION__);
#else
    /*申请某个GPIO管脚*/
    gpio_request(S5PV210_GPC0(3),"led0");
    gpio_request(S5PV210_GPC0(4),"led1");
    /*配置某个管脚为输入功能*/
    s3c_gpio_cfgpin(S5PV210_GPC0(3),S3C_GPIO_OUTPUT);
    s3c_gpio_cfgpin(S5PV210_GPC0(4),S3C_GPIO_OUTPUT);

#endif

    return 0;
}

ssize_t led_write (struct file *filp, const char __user *buf, size_t size, loff_t *ofs)
{
    int get_ret = 0;
    int led_signal=0;

    get_ret = copy_from_user(&led_signal,buf,1);
    if(get_ret == 0)
    {
        if(!led_signal)
        {//亮
            //*GPC0DAT &= ~0x18;
            gpio_direction_output(S5PV210_GPC0(3),1);
            gpio_direction_output(S5PV210_GPC0(4),1);
        }
        else
        {//灭
            //*GPC0DAT |= 0x18;
            gpio_direction_output(S5PV210_GPC0(3),0);
            gpio_direction_output(S5PV210_GPC0(4),0);
        }
    }
    return get_ret?-EFAULT:size;

    printk(KERN_INFO"----%s--------\n", __FUNCTION__);
}
ssize_t led_read (struct file *filp, char __user *buf, size_t size, loff_t *ofs)
{
    printk(KERN_INFO"----%s--------\n", __FUNCTION__);
    return 0;
}
int led_close(struct inode *inode, struct file *filp)
{
    printk(KERN_INFO"----%s--------\n", __FUNCTION__);
    return 0;
}
long ioctl(struct file *filp, unsigned int argc, unsigned long argv)
{
    if(argc ==19870322)
    {

         //*GPC0DAT &= ~0x10;
         //*GPC0DAT |= 0x08;
         gpio_direction_output(S5PV210_GPC0(3),1);
         gpio_direction_output(S5PV210_GPC0(4),0);
    }
    if(argv==610428)
    {
         //*GPC0DAT &= ~0x08;
         //*GPC0DAT |= 0x10;
         gpio_direction_output(S5PV210_GPC0(3),0);
         gpio_direction_output(S5PV210_GPC0(4),1);
    }
    printk(KERN_INFO"----%s--------\n", __FUNCTION__);
    return 0;
}


//驱动文件为用户空间提供的操作函数(函数)
struct file_operations led_file={
        .owner = THIS_MODULE,
        .open = led_open,
        .write = led_write,
        .read = led_read,
        .release= led_close,
        .unlocked_ioctl = ioctl,
};

static int __init led_init(void)
{
  //加载驱动过程
  //1.为设备分配一个空间
  led_dev = kmalloc(sizeof(struct s5p210_led),GFP_KERNEL);

  if(NULL == led_dev)
  {
      printk(KERN_ERR"kmalloc error!\n");
     return -ENOMEM;
  }
  //2.申请设备号(自动申请设备号)
  ret = register_chrdev(0,"s5pv210_led_drv",&led_file);
  if(ret <=0)
  {
        printk(KERN_ERR"register_chrdev!\n");
        ret = -EINVAL;
        goto err_1;
  }
  //返回的主设备号ret
  led_dev->devno = MKDEV(ret,0);
  //3.创建与用户空间关联的文件
  led_dev->cls = class_create(THIS_MODULE,"s5pv_led_class");
  if(!led_dev->cls)
  {
        ret = PTR_ERR(led_dev->cls);
        goto err_2;
  }
  led_dev->dev = device_create(led_dev->cls,NULL,led_dev->devno,NULL,"s5pv210_led_drv");
  if(!led_dev->dev)
  {
        ret = PTR_ERR(led_dev->dev);
        goto err_3;
  }
  //4.为硬件申请内存资源虚拟地址
  /*GPC0CON = ioremap(PA_GPC0CON,24);
  if(NULL == GPC0CON)
  {
        ret = -ENOMEM;
        goto err_4;
  }
  GPC0DAT = GPC0CON +1;
  */
  printk(KERN_INFO"----%s--------\n", __FUNCTION__);
  return 0;
//err_4:
// device_destroy(led_dev->cls,led_dev->devno);
err_3:
  class_destroy(led_dev->cls);
err_2:
  unregister_chrdev(MAJOR(led_dev->devno),"led_drv");
err_1:
  kfree(led_dev);
  return ret;

}
static void __exit led_exit(void)
{
  //释放申请的资源
  //iounmap(GPC0CON);
  kfree(led_dev);
  unregister_chrdev(MAJOR(led_dev->devno),"led_drv");
  device_destroy(led_dev->cls,led_dev->devno);
  class_destroy(led_dev->cls);
  printk(KERN_INFO"----%s--------\n", __FUNCTION__);
}



//模块加载卸载函数
module_init(led_init);
module_exit(led_exit);
MODULE_LICENSE("GPL");

/*********************LED驱动测试程序*********************************/

#include<stdio.h>
#include<errno.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stropts.h>

int main(int argc ,char *argv[])
{
    int fd = -1;
    int on =1;
    int off = 0;
    fd = open("/dev/s5pv210_led_drv",O_RDWR);
    if(fd ==-1)
    {
        perror("open");
        return -1;
    }
    while(1)
    {
        //write(fd,&on,1);
        //sleep(1);
     　　//write(fd,&off,1);
        //sleep(1);
        ioctl(fd,19870322,1);
        sleep(1);
        ioctl(fd,1,610428);
        sleep(1);

    }
    return 0;
}