驱动开发day2（编程实现LED三盏小灯亮灭）
头文件（head.h）：
#ifndef __HEAD_H__
#define __HEAD_H__
#define PHY_LED1_MODER 0x50006000
#define PHY_LED2_MODER 0x50007000
#define PHY_LED3_MODER 0x50006000
#define PHY_LED1_ODR 0x50006014
#define PHY_LED2_ODR 0x50007014
#define PHY_LED3_ODR 0x50006014
#define PHY_RCC 0x50000A28
#endif 驱动文件（demo.c）：
#include
#include
#include
#include
#include
#include "head.h"
unsigned int major;
char kbuf[128]="";
//LED1:PE10 LED2:PF10 LED3:PE8
//定义RCC控制器指针指向映射后的虚拟内存
unsigned int *vir_rcc;
//LED1定义两个指针指向映射后的虚拟内存
unsigned int *vir_moder_led1;
unsigned int *vir_odr_led1;
//LED2定义两个指针指向映射后的虚拟内存
unsigned int *vir_moder_led2;
unsigned int *vir_odr_led2;
//LED3定义两个指针指向映射后的虚拟内存
unsigned int *vir_moder_led3;
unsigned int *vir_odr_led3;
//封装方法
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 *loff)
{
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
int ret;
ret=copy_to_user(ubuf,kbuf,size);
if(ret)
{
printk("copy_to_user filed\n");
return -EIO;
}
return 0;
}
ssize_t mydev_write(struct file *file,const char *ubuf,size_t size,loff_t *loff)
{
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
int ret;
ret=copy_from_user(kbuf,ubuf,size);
if(ret)
{
printk("copy_from_user filed\n");
return -EIO;
}
if(kbuf[0] == '0')//关灯
{
//关灯逻辑
(*vir_odr_led1)&=(~(0x1 << 10)); //LED1默认关灯
(*vir_odr_led2)&=(~(0x1 << 10)); //LED2默认关灯
(*vir_odr_led3)&=(~(0x1 << 8)); //LED3默认关灯
}
else if (kbuf[0] == '1')
{
//开灯逻辑
(*vir_odr_led1) |= (0x1 << 10); //LED1开灯
(*vir_odr_led2) |= (0x1 << 10); //LED2开灯
(*vir_odr_led3) |= (0x1 << 8); //LED3开灯
}
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=mydev_write,
.release=mycdev_close,
};
static int __init mydev_init(void)
{
//注册字符设备驱动
major = register_chrdev(0,"mychrdev", &fops);
if(major < 0)
{
printk("字符设备驱动注册失败\n");
return major;
}
printk("注册字符设备驱动成功major=%d\n",major);
//RCC控制器地址映射
vir_rcc = ioremap(PHY_RCC,4);
if(vir_rcc == NULL)
{
printk("物理内存地址映射失败%d\n",__LINE__);
return -1;
}
//LED1进行寄存器的地址映射
vir_moder_led1 = ioremap(PHY_LED1_MODER,4);
if(vir_moder_led1 == NULL)
{
printk("物理内存地址映射失败%d\n",__LINE__);
return -1;
}
vir_odr_led1 = ioremap(PHY_LED1_ODR,4);
if(vir_odr_led1 == NULL)
{
printk("物理内存地址映射失败%d\n",__LINE__);
return -1;
}
printk("LED1寄存器内存映射成功");
//LED2进行寄存器的地址映射
vir_moder_led2 = ioremap(PHY_LED2_MODER,4);
if(vir_moder_led2 == NULL)
{
printk("物理内存地址映射失败%d\n",__LINE__);
return -1;
}
vir_odr_led2 = ioremap(PHY_LED2_ODR,4);
if(vir_odr_led2 == NULL)
{
printk("物理内存地址映射失败%d\n",__LINE__);
return -1;
}
printk("LED2寄存器内存映射成功");
//LED3进行寄存器的地址映射
vir_moder_led3 = ioremap(PHY_LED3_MODER,4);
if(vir_moder_led3 == NULL)
{
printk("物理内存地址映射失败%d\n",__LINE__);
return -1;
}
vir_odr_led3 = ioremap(PHY_LED3_ODR,4);
if(vir_odr_led3 == NULL)
{
printk("物理内存地址映射失败%d\n",__LINE__);
return -1;
}
printk("LED3寄存器内存映射成功");
//RCC寄存器初始化
(*vir_rcc) |= (0x3 << 4);//GPIOE/GPIOF控制器时钟使能
//LED1寄存器初始化
(*vir_moder_led1) &= (~(0x3 << 20));//MODER[21:20]->00
(*vir_moder_led1) |= (0x1 << 20);//MODER[21:20]->01
(*vir_odr_led1) &= (~(0x1 << 10));//默认关灯
//LED2寄存器初始化
(*vir_moder_led2) &= (~(0x3 << 20));//MODER[21:20]->00
(*vir_moder_led2) |= (0x1 << 20);//MODER[21:20]->01
(*vir_odr_led2) &= (~(0x1 << 10));//默认关灯
//LED3寄存器初始化
(*vir_moder_led3) &= (~(0x3 << 16));//MODER[17:16]->00
(*vir_moder_led3) |= (0x1 << 16);//MODER[17:16]->01
(*vir_odr_led3) &= (~(0x1 << 8));//默认关灯
return 0;
}
static void __exit mydev_exit(void)
{
//取消RCC控制器内存映射
iounmap(vir_rcc);
//取消LED1内存映射
iounmap(vir_moder_led1);
iounmap(vir_odr_led1);
//取消LED2内存映射
iounmap(vir_moder_led2);
iounmap(vir_odr_led2);
//取消LED3内存映射
iounmap(vir_moder_led3);
iounmap(vir_odr_led3);
//注销字符设备驱动
unregister_chrdev(major,"mychrdev");
}
module_init(mydev_init);
module_exit(mydev_exit);
MODULE_LICENSE("GPL");
c文件（test.c）：
#include
#include
#include
#include
#include
#include
int main(int argc, char const *argv[])
{
char buf[128]="";
int fd=open("/dev/mychrdev",O_RDWR);
if(fd<0)
{
printf("打开设备文件失败\n");
return -1;
}
printf("打开设备文件成功\n");
while(1)
{
printf("请输入要进行的操作,0(关灯),1(开灯) >");
fgets(buf,sizeof(buf),stdin);
buf[strlen(buf)-1]='\0';
write(fd,buf,sizeof(buf));
}
close(fd);
return 0;
}
效果图：
