任务:使用模块化编译安装驱动实现三盏LED灯的亮灭
驱动程序
#include
#include
#include
#include
#include
#define PHY_RCC 0X50000A28
#define PHY_LED1_MODER 0x50006000
#define PHY_LED2_MODER 0x50007000
#define PHY_LED1_ODR 0x50006014
#define PHY_LED2_ODR 0x50007014
unsigned int major;
char kbuf[128] = "";
unsigned int *vir_rcc;
unsigned int *vir_moder1;
unsigned int *vir_odr1;
unsigned int *vir_moder2;
unsigned int *vir_odr2;
int mycdev_open(struct inode *inode,struct file *file)
{
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
return 0;
}
ssize_t mycdev_read(struct file *file,char *ubuf,size_t size,loff_t *lof)
{
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
unsigned long ret;
ret = copy_to_user(ubuf,kbuf,size);
if(ret)
{
printk("copy_to_user_failed\n");
return -EIO;
}
return 0;
}
ssize_t mycdev_write(struct file *file,const char *ubuf,size_t size,loff_t *lof)
{
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
unsigned long ret;
ret = copy_from_user(kbuf,ubuf,size);
if(ret)
{
printk("copy_from_user_failed\n");
return -EIO;
}
if(kbuf[0] == '0')
{
//关闭LED1灯
printk("LED1 OFF\n");
(*vir_odr1) &= (~(0x1 << 10));
}
else if(kbuf[0] == '1')
{
//打开LED1灯
printk("LED1 ON\n");
(*vir_odr1) |= (0x1 << 10);
}
if(kbuf[1] == '0')
{
//关闭LED2灯
printk("LED2 OFF\n");
(*vir_odr2) &= (~(0x1 << 10));
}
else if(kbuf[1] == '1')
{
//打开LED2灯
printk("LED2 ON\n");
(*vir_odr2) |= (0x1 << 10);
}
if(kbuf[2] == '0')
{
//关闭LED3灯
printk("LED3 OFF\n");
(*vir_odr1) &= (~(0x1 << 8));
}
else if(kbuf[2] == '1')
{
//打开LED3灯
printk("LED3 ON\n");
(*vir_odr1) |= (0x1 << 8);
}
return 0;
}
int mycdev_close(struct inode *inode,struct file *file)
{
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
return 0;
}
struct file_operations fops={
.open=mycdev_open,
.read=mycdev_read,
.write=mycdev_write,
.release=mycdev_close,
};
static int __init mycdev_init(void)
{
major = register_chrdev(0,"mydev",&fops);
if(major < 0)
{
printk("字符设备注册失败\n");
return major;
}
else
{
printk("字符设备注册成功,major=%d\n",major);
}
//物理地址映射到虚拟地址上
vir_rcc = ioremap(PHY_RCC,4);
if(vir_rcc == NULL)
{
printk("映射失败 : %d\n",__LINE__);
return -EFAULT;
}
//LED1/3
vir_moder1 = ioremap(PHY_LED1_MODER,4);
if(vir_moder1 == NULL)
{
printk("映射失败 : %d\n",__LINE__);
return -EFAULT;
}
vir_odr1 = ioremap(PHY_LED1_ODR,4);
if(vir_odr1 == NULL)
{
printk("映射失败 : %d\n",__LINE__);
return -EFAULT;
}
//LED2
vir_moder2 = ioremap(PHY_LED2_MODER,4);
if(vir_moder2 == NULL)
{
printk("映射失败 : %d\n",__LINE__);
return -EFAULT;
}
vir_odr2 = ioremap(PHY_LED2_ODR,4);
if(vir_odr2 == NULL)
{
printk("映射失败 : %d\n",__LINE__);
return -EFAULT;
}
printk("映射成功\n");
//串口初始化
(*vir_rcc) |= (0x3 << 4);
//LED1初始化
(*vir_moder1) &= (~(0x3 << 20));
(*vir_moder1) |= (0x1 << 20);
(*vir_odr1) &= (~(0x1 << 10));
//LED2初始化
(*vir_moder2) &= (~(0x3 << 20));
(*vir_moder2) |= (0x1 << 20);
(*vir_odr2) &= (~(0x1 << 10));
//LED3初始化
(*vir_moder1) &= (~(0x3 << 16));
(*vir_moder1) |= (0x1 << 16);
(*vir_odr1) &= (~(0x1 << 8));
printk("LED初始化成功\n");
return 0;
}
static void __exit mycdev_exit(void)
{
//取消映射
iounmap(vir_rcc);
iounmap(vir_moder1);
iounmap(vir_odr1);
iounmap(vir_moder2);
iounmap(vir_odr2);
unregister_chrdev(major,"mydev");
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");
应用程序
#include
#include
#include
#include
#include
#include
int main()
{
int fd=open("/dev/mychrdev",O_RDWR);
if(fd < 0)
{
printf("文件打开失败\n");
return -1;
}
else
{
printf("文件打开成功\n");
}
char buf[128]="";
while(1)
{
memset(buf,0,sizeof(buf));
printf("请输入LED1/2/3的状态(1:ON/0:OFF)>>");
fgets(buf,sizeof(buf),stdin);
buf[strlen(buf)-1]='\0';
if(buf[0]=='q')
{
break;
}
write(fd,buf,sizeof(buf));
memset(buf,0,sizeof(buf));
read(fd,buf,sizeof(buf));
printf("buf : %s\n",buf);
}
close(fd);
return 0;
}
串口现象:
开发板现象: