驱动开发学习之字符设备同时点亮三盏LED灯

head.h

#ifndef __HEAD_H__
#define __HEAD_H__
#define PHY_LED1_RCC   0X50000A28
//PE10
#define PHY_LED1_MODER 0X50006000
#define PHY_LED1_ODR   0X50006014
//PF10
#define PHY_LED2_MODER 0X50007000
#define PHY_LED2_ODR   0X50007014
//PE8
#define PHY_LED3_MODER 0X50006000
#define PHY_LED3_ODR   0X50006014


#endif

test.c

#include 
#include 
#include 
#include 
#include 
#include 
#include 
int main(int argc, char const *argv[])
{
    char buf[128] = {0};

    int fd = open("/dev/mychrdev", O_RDWR);
    if (fd < 0)
    {
        printf("打开设备文件失败\n");
        exit(-1);
    }
    while (1)
    {
        printf("请输入控制命令：0（关灯）1（开灯）>");
        fgets(buf, sizeof(buf), stdin); // 从终端输入数据到buf
        buf[strlen(buf) - 1] = '\0';    // 将buf末尾的'\n'切换为'\0'
        write(fd, buf, sizeof(buf));
    }
    close(fd);
    return 0;
}

mychrdev.c

#include 
#include 
#include
#include
#include"head.h"
unsigned int major;//定义一个变量保存主设备号
char kbuf[128]={0};
unsigned int *vir_moder;
unsigned int *vir_odr;
unsigned int *vir_rcc;
unsigned int *vir_moder1;
unsigned int *vir_odr1;
unsigned int *vir_moder2;
unsigned int *vir_odr2;
//封装操作方法
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 *lof)
{
     printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
      long ret;
     ret=copy_to_user(ubuf,kbuf,size);
     if(ret)
     {
        printk("copy_to_user filed\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__);
      long ret;
     ret=copy_from_user(kbuf,ubuf,size);
     if(ret)
     {
        printk("copy_from_user filed\n");
        return -EIO;
     }
     //判断用户输入的数据，进行不同的硬件逻辑执行
     if(kbuf[0]=='0')//关灯
     {
        //关灯逻辑
          (*vir_odr) &= (~(0X1<<10));
          (*vir_odr1) &= (~(0X1<<10));
          (*vir_odr2) &= (~(0X1<<8));
     }
     else if(kbuf[0]=='1')
     {
        //开灯逻辑
        (*vir_odr) |=(0X1<<10);
        (*vir_odr1) |=(0X1<<10);
        (*vir_odr2) |=(0X1<<8);
     }
    return 0;
}
int mycdev_close(struct inode *inode, struct file *file)
{
     printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    return 0;
}
//定义一个操作方法结构体变量并且初始化
struct file_operations fops={
    .open=mycdev_open,
    .release=mycdev_close,
    .read=mycdev_read,
    .write=mycdev_write,
};
static int __init mycdev_init(void)
{
    //注册字符设备驱动
    major=register_chrdev(0,"mychrdev",&fops);
    if(major<0)
    {
        printk("注册字符设备驱动失败\n");
        return major;
    }
    printk("注册字符设备驱动成功major=%d\n",major);
    //进行寄存器地址的映射
    vir_moder=ioremap(PHY_LED1_MODER,4);
    if(vir_moder==NULL)
    {
        printk("映射物理内存失败%d\n",__LINE__);
        return -EFAULT;
    }
    vir_odr=ioremap(PHY_LED1_ODR,4);
    if(vir_odr==NULL)
    {
        printk("映射物理内存失败%d\n",__LINE__);
        return -EFAULT;
    }
    vir_rcc=ioremap(PHY_LED1_RCC,4);
    if(vir_rcc==NULL)
    {
        printk("映射物理内存失败%d\n",__LINE__);
        return -EFAULT;
    }
    printk("映射物理内存成功\n");
     //进行寄存器地址的映射
    vir_moder1=ioremap(PHY_LED2_MODER,4);
    if(vir_moder1==NULL)
    {
        printk("映射物理内存失败%d\n",__LINE__);
        return -EFAULT;
    }
    vir_odr1=ioremap(PHY_LED2_ODR,4);
    if(vir_odr1==NULL)
    {
        printk("映射物理内存失败%d\n",__LINE__);
        return -EFAULT;
    }
    printk("映射物理内存成功\n");
     //进行寄存器地址的映射
    vir_moder2=ioremap(PHY_LED3_MODER,4);
    if(vir_moder2==NULL)
    {
        printk("映射物理内存失败%d\n",__LINE__);
        return -EFAULT;
    }
    vir_odr2=ioremap(PHY_LED3_ODR,4);
    if(vir_odr2==NULL)
    {
        printk("映射物理内存失败%d\n",__LINE__);
        return -EFAULT;
    }
    printk("映射物理内存成功\n");
    //硬件寄存器的初始化
    (*vir_rcc)|=(0X1<<4);//rcc使能
    (*vir_moder) &=(~(0X3<<20));//设置为输出
    (*vir_moder) |=(0X1<<20);
    (*vir_odr) &= (~(0X1<<10));//输出低电平
     //硬件寄存器的初始化
    (*vir_rcc)|=(0X1<<5);//rcc使能
    (*vir_moder1) &=(~(0X3<<20));//设置为输出
    (*vir_moder1) |=(0X1<<20);
    (*vir_odr1) &= (~(0X1<<10));//输出低电平
     //硬件寄存器的初始化
    (*vir_moder2) &=(~(0X3<<16));//设置为输出
    (*vir_moder2) |=(0X1<<16);
    (*vir_odr2) &= (~(0X1<<8));//输出低电平
    printk("硬件寄存器初始化成功\n");
    return 0;
}
static void __exit mycdev_exit(void)
{
    //注销字符设备驱动
    unregister_chrdev(major,"mychrdev");

}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");