一个简单的mini2440 led驱动程序

经过两个小时的编写,终于成功的写完mini2440开发板led的驱动.

#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include

#define DEVICE_NAME "miniled"
#define LED_MAJOR 254

static int led_major = LED_MAJOR;

struct mini_led_dev
{
 struct cdev cdev;
 
};

struct mini_led_dev *devp;

static unsigned long mini_led_table[] = {
 S3C2410_GPB5,
 S3C2410_GPB6,
 S3C2410_GPB7,
 S3C2410_GPB8,
};

static unsigned long mini_led_cfg_table[] = {
 S3C2410_GPB5_OUTP,
 S3C2410_GPB6_OUTP,
 S3C2410_GPB7_OUTP,
 S3C2410_GPB8_OUTP,
};

int led_on(int arg)
{
 s3c2410_gpio_setpin(mini_led_table[arg], 0);
 return 0;
}

int led_off(int arg)
{
 s3c2410_gpio_setpin(mini_led_table[arg], 1);
 return 0;
}

static int mini_led_ioctl(struct inode *inode, struct file *file,
      unsigned int cmd, unsigned long arg)
{
 switch(cmd)
 {
  case 0:
   led_off(arg);
   break;
  case 1:
   led_on(arg);
   break;
  default:
   return -1; 
 }
}

static int mini_led_open(struct inode *inode, struct file *filp)
{
 struct mini_led_dev *devp;
 
 devp = container_of(inode->i_cdev, struct mini_led_dev,cdev);
 filp->private_data = devp;
 
 return 0;
}

static int mini_led_release(struct inode *inode, struct file *filp)
{
 return 0;
}

static struct file_operations mini_led_fops = {
 .owner = THIS_MODULE,
 .ioctl = mini_led_ioctl,
 .open = mini_led_open,
 .release = mini_led_release,
};

static void led_setup_cdev(struct mini_led_dev *dev, int index)
{
 int err;
 int devno = MKDEV(led_major, index);

 cdev_init(&dev->cdev, &mini_led_fops);
 dev->cdev.owner = THIS_MODULE;
 dev->cdev.ops = &mini_led_fops;
 err = cdev_add(&dev->cdev, devno, 1);

 if (err)
 {
  printk(KERN_NOTICE "Error %d adding led %d", err, index);
 }
}

int mini_led_init(void)
{
 int result;
 int i;

 dev_t devno = MKDEV(led_major, 0);
 if (led_major)
 {
  result = register_chrdev_region(devno, 0, DEVICE_NAME); 
 }
 else
 {
  result = alloc_chrdev_region(&devno, 0, 1, DEVICE_NAME);
 }
 if (result < 0)
 { 
  return result;
 }

 devp = kmalloc(sizeof(struct mini_led_dev), GFP_KERNEL);
 if (! devp)
 {
  result = -1;
  goto fail_malloc;
 }
 
 for (i = 0; i < 4; i++)
 {
  s3c2410_gpio_cfgpin(mini_led_table[i], mini_led_cfg_table[i]);
  s3c2410_gpio_setpin(mini_led_table[i], 1);
 }
 memset(devp, 0, sizeof(struct mini_led_dev));
 
 led_setup_cdev(devp, 0);
 
 return 0; 
 
 fail_malloc:
  unregister_chrdev_region(devno, 1);
  return result;

}

void mini_led_exit(void)
{
 cdev_del(&devp->cdev);
 kfree(devp);
 unregister_chrdev_region(MKDEV(led_major, 0), 1);
}

MODULE_AUTHOR("more&high");
MODULE_LICENSE("Dual BSD/GPL");

module_init(mini_led_init);
module_exit(mini_led_exit);

 

 

以下是Makefile:

obj-m := led.o

KDIR := /opt/friendlyarm/mini2440/kernel-2.6.13

PWD := $(shell pwd)

CC = arm-linux-gcc

default:
 $(MAKE) -C $(KDIR) SUBDIRS=$(PWD) modules

clean:
 rm -rf *.o
 rm -rf *.ko
 rm -rf .*.cmd
 rm -rf *.mod.*

 

make

 

成功

 

mknod /dev/testled c 254 0

 

insmod led.ko

 

以下是应用程序

 

#include
#include
#include
#include

int main()
{
 int fd;
 int num;
 int ope;
 
 fd = open("/dev/testled", 0);
 if (fd < 0)
 {
  perror("open miniled fail");
  exit(1);
 }
 for ( num = 0; num < 4; num++)
 {
  ioctl(fd, 0, num);
 }
 printf("please print the led num\n");
 scanf("%d", &num);
 printf("please print the operation\n");
 scanf("%d", &ope);
 ioctl(fd, ope, num);
 
 close(fd);
 
 return 0;

}