#include <linux/init.h>
#include <linux/module.h>
#include <linux/cdev.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
struct cdev *cdev
char kbuf128=0;
unsigned int major=0;
unsigned int minor=0;
dev_t devno;
module-param(major,unit,0664); //方便在命令行传递major的值
struct class*cls;
struct device *dev;
struct mutex mutex; //定义互斥体
int mycdev_open(struct inode *inode,struct file*file)
{
mutex_lock(&mutex);//上锁
printk("%s:%s:%d\n",FILE,func,LINE);
return 0;
}
long mycdev_ioctl(struct file *file,unsigned int cmd,unsigned long arg)
{
int which;
//获取arg对应的用户空间中的值
int ret=copy_from_user(&which,(void *)arg,4);
if(ret)
{
printk("从用户空间获取数据失败\n");
return -EIO;
}
switch (cmd)
{
case LED_ON:
switch(which)
{
case 1: //LED1
vir_led1->ODR |= 1 << 10;
break;
case 2:
vir_led2->ODR |= 1 << 10;
break;
case 3:
vir_led3->ODR |= 1 << 8;
break;
}
break;
case LED_OFF:
switch(which)
{
case 1: //LED1
vir_led1->ODR &= (~(1 << 10));
break;
case 2:
vir_led2->ODR &= (~(1 << 10));
break;
case 3:
vir_led3->ODR &= (~(1 << 8));
break;
}
break;
}
return 0;
}
nt mycdev_close(struct inode *inode,struct file *file)
{
mutex_unlock(mutex);//解锁
printk("%s:%s:%d\n",FILE,func,LINE);
return 0;
}
//定义操作方法结构体变量并赋值
struct file_operation fops={
.open=mycdev_open,
.read=mycdev_read,
.write=mycdev_write,
.realease=mycdev_close,
};
int all_led_init(void)
{
vir_led1=ioremap(PHY_LED1_ADDR,sizeof(gpio_t));
if(vir_led1==NULL)
{
printk("ioremap filed: %d\n",LINE);
return -ENOMEM;
}
vir_led2=ioremap(PHY_LED2_ADDR,sizeof(gpio_t));
if(vir_led2==NULL)
{
printk("ioremap filed: %d\n",LINE);
return -ENOMEM;
}
vir_led3=vir_led1;
vir_rcc=ioremap(PHY_RCC_ADDR,4);
if(vir_rcc==NULL)
{
printk("ioremap filed: %d\n",LINE);
return -ENOMEM;
}
printk("物理地址映射成功\n");
//寄存器的初始化
//rcc
(*vir_rcc) |= (0x3<<4);
//LED1
vir_led1->MODER &= (~(3<<20));
vir_led1->MODER |= (1<<20);
vir_led1->ODR &= (~(1<<10));
//LED2
vir_led2->MODER &= (~(3<<20));
vir_led2->MODER |= (1<<20);
vir_led2->ODR &= (~(1<<10));
//LED3
vir_led3->MODER &= (~(3<<16));
vir_led3->MODER |= (1<<16;
vir_led3->ODR &= (~(1<<8));
printk("寄存器初始化成功\n");
return 0;
}
static int __init mycdev_init(void)
{
int ret;
//为字符设备驱动对象申请空间
cdev=cdev_alloc();
if(cdev==NULL)
{
printk(" 字符设备驱动对象申请空间失败\n");
ret=-EFAULT;
goto out1;
}
printk("申请对象空间成功");
//初始化字符设备驱动对象
cdev------init(cdev,&fops);
//申请设备号
if(major>0)//静态指定设备号
{
ret=register_chrdev_region(MKDEV(major,minor),3,"myled");
if(ret)
{
printk("静态申请设备号失败\n");
goto out2;
}
}
else if(major==0)//动态申请设备号
{
ret=register_chrdev_region(MKDEV(major,minor),3,"myled");
if(ret)
{
printk("动态申请设备号失败\n");
goto out2;
}
major=MAJOR(devno);//获取主设备号
major=MINOR(devno);//获取次设备号
}
printk("申请设备号成功\n");
mutex_init(&mutex);//初始化互斥体
//字符设备驱动对象注册
ret=cdev_add(cdev,MKDEV(major,minor),3);
if(ret)
{
printk("字符设备驱动对象注册失败\n");
goto out3;
}
printk("字符设备驱动对象注册成功\n");
//寄存器映射以及初始化
all_led_init();
//向上提交目录
cls=class_create(THIS_MODULE,"myled");
if(IS_ERR(cls))
{
printk("向上提交目录失败\n");
return -PTR_ERR(cls);
goto out4;
}
printk("向上提交目录成功\n");
//向上提交设备节点信息
int i;
for(i=0;i<3;i++)
{
dev=device_create(cls,NULL,MKDEV(major,i)NULL,"mychrdevv%d",i);
if(IS_ERR(dev))
{
printk("向上提交设备节点信息失败\n");
return -PTR_ERR(dev);
}
}
printk("向上提交设备节点信息成功\n");
return 0;
}
out5:
//释放前一次提交成功的设备信息
for(--i;i>=0;i--)
{
device_destory(cls,MKDEV(major,i));
}
class_destory(cls);//释放目录
out4:
cdev_del(cdev);
out3:
unregister_chrdev_region(MKDEV(major,minor),3);
out2:
kfree(cdev);
out1:
return ret;
static void __exit mycdev_exit(void)
{
//销毁设备节点信息
int i;
for(i=0;i<3;i++)
{
device_destory(cls,MKDEV(major,i));
}
//销毁目录信息
class_destory(cls);
//取消地址映射
iounmap(vir_led1);
iounmap(vir_led2);
iounmap(vir_rcc);
//注销字符设备驱动对象
cdev_del(cdev);
//释放设备号
unregister_chrdev_region(MKDEV(major,minor),3);
//释放对象空间
kfree(cdev);
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");