驱动字符设备 LED点亮

led.h

#ifndef __LED_H__
#define __LED_H__


#define PHY_MODER 0x50006000
#define PHY1_ODR 0x50006014
#define PHY1_RCC 0x50000A28

#define PHY2_MODER 0x50007000
#define PHY2_ODR 0x50007014

#define PHY3_MODER 0x50006000
#define PHY3_ODR 0x50006014

#endif

mycdev.c

#include 
#include 
#include
#include
#include 
#include "led.h"
unsigned int major;
char kbuf[128]={0};

//定义三个指针指向映射后的虚拟内存首地址
unsigned int *vir1_moder;
unsigned int  *vir1_odr;
unsigned int *vir_rcc;

unsigned int *vir2_moder;
unsigned int  *vir2_odr;

unsigned int *vir3_moder;
unsigned int  *vir3_odr;

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 *iof)
{
    int ret;

    if(size>sizeof(kbuf))
    size=sizeof(kbuf);
    ret=copy_to_user(ubuf,kbuf,size);
    if(ret)
    {
        printk("copy to user filed\n");
        return -EIO;
    }
    printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    return 0; 
}

ssize_t mycdev_write(struct file *file,const char *ubuf,size_t size,loff_t *iof)
{
    printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    int ret;

    if(size>sizeof(kbuf))
    size=sizeof(kbuf);
    ret=copy_from_user(kbuf,ubuf,size);
    if(ret)
    {
        printk("copy from user filed\n");
        return -EIO;
    }
    //根据用户空间发送来的指令实现灯的亮灭控制
    if(kbuf[0]=='1')//亮灯
    {
        (*vir1_odr) |= (0X1<<10);
        (*vir2_odr) |= (0X1<<10);
        (*vir3_odr) |= (0X1<<8);
    }
    else if(kbuf[0]=='0')//灭灯
    {
        (*vir1_odr) &= (~(0X1<<10));
        (*vir2_odr) &= (~(0X1<<10));
        (*vir3_odr) &= (~(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)
{
    //字符设备驱动的注册
    major=register_chrdev(0,"mycdev",&fops);
    if(major<0)
    {
        printk("字符设备驱动注册失败\n");
        return major;
    }
    printk("字符设备驱动注册成功major=%d\n",major);

    //进行LED相关寄存器地址映射
    vir1_moder=ioremap(PHY_MODER,4);
    if(vir1_moder==NULL)
    {
        printk("物理内存映射失败\n");
        return -EFAULT;
    }
    vir1_odr=ioremap(PHY1_ODR,4);
    if(vir1_odr==NULL)
    {
        printk("物理内存映射失败\n");
        return -EFAULT;
    }


    vir2_moder=ioremap(PHY_MODER,4);
    if(vir2_moder==NULL)
    {
        printk("物理内存映射失败\n");
        return -EFAULT;
    }
    vir2_odr=ioremap(PHY1_ODR,4);
    if(vir2_odr==NULL)
    {
        printk("物理内存映射失败\n");
        return -EFAULT;
    }


    vir3_moder=ioremap(PHY_MODER,4);
    if(vir3_moder==NULL)
    {
        printk("物理内存映射失败\n");
        return -EFAULT;
    }
    vir3_odr=ioremap(PHY1_ODR,4);
    if(vir3_odr==NULL)
    {
        printk("物理内存映射失败\n");
        return -EFAULT;
    }


    vir_rcc=ioremap(PHY1_RCC,4);
    if(vir_rcc==NULL)
    {
        printk("物理内存映射失败\n");
        return -EFAULT;
    }
    printk("物理内存映射为虚拟内存成功\n");

    //相关寄存器初始化
    (*vir_rcc) |= (0x1<<4);//gpio使能
    //LED1灯初始化
    (*vir1_moder) &= (~(0x3<<20));//设置为输出
    (*vir1_moder) |= (0x1<<20);
    (*vir1_odr) &= (~(0x1<<10));//灭灯

    //LED2灯初始化
    (*vir2_moder) &= (~(0x3<<20));//设置为输出
    (*vir2_moder) |= (0x1<<20);
    (*vir2_odr) &= (~(0x1<<10));//灭灯

    //LED3灯初始化
    (*vir3_moder) &= (~(0x3<<16));//设置为输出
    (*vir3_moder) |= (0x1<<16);
    (*vir3_odr) &= (~(0x1<<8));//灭灯
    printk("相关寄存器初始化成功\n");
    return 0;
}

static void __exit mycdev_exit(void)
{

    //字符设备驱动的注销
    unregister_chrdev(major,"mycdev");
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");

test.c

#include
#include 
#include 
#include 
#include 
#include
#include 
int main(int argc, char const *argv[])
{
    char buf[128]={0};
    int fd=open("/dev/mycdev",O_RDWR);
    if(fd<0)
    {
        printf("打开文件失败\n");
        exit(-1);
    }

    while(1)
    {
        printf("输入控制码： 1 (亮灯) 0 (灭灯) >>>");
        fgets(buf,sizeof(buf),stdin);
        buf[strlen(buf)-1]='\0';
        write(fd,buf,sizeof(buf));
    }

    close(fd);

    return 0;
}