2023/5/17 用户程序控制三盏灯的亮灭

led1：0：灭；1：亮
led2：0：灭；1：亮
led3：0：灭；1：亮
输入格式：例：000、101

head.h

#ifndef __HEAD_H__
#define __HEAD_H__

#define RCC_AHB4_ENSETR   0x50000a28

#define GPIOE_MODER       0x50006000
#define GPIOE_ODR         0x50006014

#define GPIOF_MODER       0x50007000
#define GPIOF_ODR         0x50007014

#define GPIO_PIN_8 8
#define GPIO_PIN_10 10

#endif

mycdev.c

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/io.h>

#include "head.h"

unsigned int major;

char kbuf[128] = {0};


unsigned int *vir_rcc;

unsigned int *vir_moder1;
unsigned int *vir_odr1;
unsigned int *vir_odr3;

unsigned int *vir_moder2;
unsigned int *vir_odr2;


//封装驱动中的操作方法
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)
{
    int ret;
    //判断用户的需求，如果内核满足不了，给内核能满足的最大值
    if(size > sizeof(kbuf))
    {
        size = sizeof(kbuf);
    }
    ret = copy_to_user(ubuf,kbuf,size);//内核向用户拷贝数据
    if(ret)
    {
        printk("copy_to_user failed __%d__\n",__LINE__);
        return ret;
    }
    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 *lof)
{
    int ret;
    //判断用户的需求，如果内核满足不了，给内核能满足的最大值
    if(size > sizeof(kbuf))
    {
        size = sizeof(kbuf);
    }
    ret = copy_from_user(kbuf,ubuf,size);
    if(ret)
    {
        printk("copy_from_user failed __%d__\n",__LINE__);
        return ret;
    }
    printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);

    //LED1开关
    if('1' == kbuf[0])//开灯
    {
        (*vir_odr1) |= (1 << GPIO_PIN_10);
    }else if('0' == kbuf[0])
    {
        (*vir_odr1) &= (~(1 << GPIO_PIN_10));
    }

    //LED2开关
     if('1' == kbuf[1])//开灯
    {
        (*vir_odr2) |= (1 << GPIO_PIN_10);
    }else if('0' == kbuf[1])
    {
        (*vir_odr2) &= (~(1 << GPIO_PIN_10));
    }

    //LED3开关
    if('1' == kbuf[2])//开灯
    {
        (*vir_odr3) |= (1 << GPIO_PIN_8);
    }else if('0' == kbuf[2])
    {
        (*vir_odr3) &= (~(1 << GPIO_PIN_8));
    }
    return 0;
}

int mycdev_close(struct inode *inode,struct file *file)
{
    printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    return 0;
}

//定义操作方法结构体变量
struct file_operations fops={
    .open = mycdev_open,
    .read = mycdev_read,
    .write = mycdev_write,
    .release = mycdev_close,
};

static int __init mycdev_init(void)
{
    //字符设备驱动注册
    major = register_chrdev(0,"mycdev",&fops);
    if(major < 0)
    {
        printk("字符设备驱动加载失败\n");
        return major;
    }
    printk("字符设备驱动加载成功,major = %d\n",major);

    //进行LED的相关寄存器映射
    vir_moder1 = ioremap(GPIOE_MODER,4);
    if(NULL == vir_moder1)
    {
        printk("寄存器映射失败 __%d__\n",__LINE__);
        return -ENOMEM;
    }

    vir_moder2 = ioremap(GPIOF_MODER,4);
    if(NULL == vir_moder2)
    {
        printk("寄存器映射失败 __%d__\n",__LINE__);
        return -ENOMEM;
    }   

    vir_odr1 = ioremap(GPIOE_ODR,4);
    if(NULL == vir_odr1)
    {
        printk("寄存器映射失败 __%d__\n",__LINE__);
        return -ENOMEM;
    }
    vir_odr3 = ioremap(GPIOE_ODR,4);
    if(NULL == vir_odr3)
    {
        printk("寄存器映射失败 __%d__\n",__LINE__);
        return -ENOMEM;
    }
    vir_odr2 = ioremap(GPIOF_ODR,4);
    if(NULL == vir_odr2)
    {
        printk("寄存器映射失败 __%d__\n",__LINE__);
        return -ENOMEM;
    }

    vir_rcc = ioremap(RCC_AHB4_ENSETR,4);
    if(NULL == vir_rcc)
    {
        printk("寄存器映射失败 __%d__\n",__LINE__);
        return -ENOMEM;
    }

    printk("寄存器映射成功\n");

    //寄存器初始化
    //LED1、LED3初始化
    (*vir_rcc) |= (1 << 4);

    (*vir_moder1) &= (~(3 << GPIO_PIN_10*2));
    (*vir_moder1) |= (1 << GPIO_PIN_10*2);
    (*vir_odr1) &= (~(1 << GPIO_PIN_10));

    (*vir_moder1) &= (~(3 << GPIO_PIN_8*2));
    (*vir_moder1) |= (1 << GPIO_PIN_8*2);
    (*vir_odr3) &= (~(1 << GPIO_PIN_8));

    //LED2初始化
    (*vir_rcc) |= (1 << 5);

    (*vir_moder2) &= (~(3 << GPIO_PIN_10*2));
    (*vir_moder2) |= (1 << GPIO_PIN_10*2);
    (*vir_odr2) &= (~(1 << GPIO_PIN_10));

    printk("寄存器初始化成功\n");

    return 0;
}
static void __exit mycdev_exit(void)
{
    //取消内存映射
    iounmap(vir_rcc);
    iounmap(vir_moder1);
    iounmap(vir_moder2);
    iounmap(vir_odr1);
    iounmap(vir_odr2);
    iounmap(vir_odr3);
    //字符设备驱动注销
    unregister_chrdev(major,"mycdev");

}

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

demo.c

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>

int main(int argc, char const *argv[])
{
    char buf[128] = {0};
    int fd = open("/dev/mycdev",O_RDWR);
    if(fd < 0)
    {
        printf("设备文件打开失败\n");
        exit(-1);
    }
    while(1)
    {    
        memset(buf,0,sizeof(buf));

        printf("请输入要进行的操作：");
        fgets(buf,sizeof(buf),stdin);
        buf[strlen(buf) -1] = 0;
        write(fd,buf,sizeof(buf));
        
        /*
        memset(buf,0,sizeof(buf));
        read(fd,buf,sizeof(buf));
        printf("buf = %s\n",buf);
        */ 
    }
    close(fd);
    return 0;
}