2023/10/30-LED灯驱动开发

 k1.c

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include "head.h"
char kbuf[128] = {};
unsigned int major;
//定义三个指针指向映射后的虚拟内存
unsigned int *vir_rcc;
unsigned int *vir_moder_led1;
unsigned int *vir_odr_led1;
unsigned int *vir_moder_led2;
unsigned int *vir_odr_led2;
unsigned int *vir_moder_led3;
unsigned int *vir_odr_led3;
// 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__);
    int ret=0;
    ret = copy_to_user(ubuf,kbuf,size);
    if(ret = 0)
    {
        printk("copy_to_user 内核->用户 filed!\n");
        return -EIO;
    }
    //printk("copy_to_user 内核->用户 success!,ubuf=%s\n",ubuf);
    printk("copy_to_user 内核->用户 success!\n");
    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__);
    int ret=0;
    ret = copy_from_user(kbuf,ubuf,size);
    if(ret = 0)
    {
        printk("copy_from_user 用户->内核 filed!\n");
        return -EIO;
    }
    //printk("copy_from_user 用户->内核 success!,ubuf=%s\n",ubuf);
    printk("copy_from_user 用户->内核 success!\n");
    if(kbuf[0] == '0') //关灯
    {
        (*vir_odr_led1) &= (~(0x1 << 10));
        (*vir_odr_led2) &= (~(0x1 << 10));
        (*vir_odr_led3) &= (~(0x1 << 8));
    }
    else if(kbuf[0] == '1') //开灯
    {
        (*vir_odr_led1) |= (0x1 << 10);
        (*vir_odr_led2) |= (0x1 << 10);
        (*vir_odr_led3) |= (0x1 << 8);
    }
    return 0;
}
int mycdev_close(struct inode *inode, struct file *file)
{
    printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    return 0;
}
//定义操作方法结构体对象
struct file_operations fops={
    .open=mycdev_open,
    .read=mycdev_read,
    .write=mycdev_write,
    .release=mycdev_close,
};
static int __init mycdev_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);
    //进行寄存器的地址映射
    vir_rcc = ioremap(PHY_RCC,4);
    if(vir_rcc == NULL)
    {
        printk("物理内存映射filed! %d\n",__LINE__);
        return -EFAULT;
    }
 
    vir_moder_led1 = ioremap(PHY_LED1_MODER,4);
    if(vir_moder_led1 == NULL)
    {
        printk("物理内存映射filed! %d\n",__LINE__);
        return -EFAULT;
    }
    vir_odr_led1 = ioremap(PHY_LED1_ODR,4);
    if(vir_odr_led1 == NULL)
    {
        printk("物理内存映射filed! %d\n",__LINE__);
        return -EFAULT;
    }
 
    vir_moder_led2 = ioremap(PHY_LED2_MODER,4);
    if(vir_moder_led2 == NULL)
    {
        printk("物理内存映射filed! %d\n",__LINE__);
        return -EFAULT;
    }
    vir_odr_led2 = ioremap(PHY_LED2_ODR,4);
    if(vir_odr_led2 == NULL)
    {
        printk("物理内存映射filed! %d\n",__LINE__);
        return -EFAULT;
    }
 
    vir_moder_led3 = ioremap(PHY_LED3_MODER,4);
    if(vir_moder_led3 == NULL)
    {
        printk("物理内存映射filed! %d\n",__LINE__);
        return -EFAULT;
    }
    vir_odr_led3 = ioremap(PHY_LED3_ODR,4);
    if(vir_odr_led3 == NULL)
    {
        printk("物理内存映射filed! %d\n",__LINE__);
        return -EFAULT;
    }
 
    printk("物理内存映射成功!\n");
 
    //LED1寄存器初始化
    (*vir_rcc) |= (0x3 << 4);         //GPIOE控制器时钟使能
 
    (*vir_moder_led1) &= (~(0x3 << 20));   //MODER[21:20] => 00
    (*vir_moder_led1) |= (0x1 << 20);      //MODER[21:20] => 01
    (*vir_odr_led1) &= (~(0x1 << 10));     //默认为关灯
 
    (*vir_moder_led2) &= (~(0x3 << 20));   //MODER[21:20] => 00
    (*vir_moder_led2) |= (0x1 << 20);      //MODER[21:20] => 01
    (*vir_odr_led2) &= (~(0x1 << 10));     //默认为关灯
 
    (*vir_moder_led3) &= (~(0x3 << 16));   //MODER[17:16] => 00
    (*vir_moder_led3) |= (0x1 << 16);      //MODER[17:16] => 01
    (*vir_odr_led3) &= (~(0x1 << 8));     //默认为关灯
 
    return 0;
}
static void __exit mycdev_exit(void)
{
    //取消内存映射
    iounmap(vir_rcc);
 
    iounmap(vir_moder_led1);
    iounmap(vir_odr_led1);
 
    iounmap(vir_moder_led2);
    iounmap(vir_odr_led2);
 
    iounmap(vir_moder_led3);
    iounmap(vir_odr_led3);
 
    //注销字符设备驱动
    unregister_chrdev(major,"mychrdev");
 
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");

test.c

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
int main(int argc,const char * argv[])
{
    char buf[128] = {0};
    int fd = open("/dev/mychrdev",O_RDWR);
    if(fd < 0)
    {
        printf("文件/dev/mychrdev打开失败\n");
        return -1;
    }
    printf("文件/dev/mychrdev打开成功\n");
 
    while(1)
    {
        printf("输入要进行的操作=> 0(关灯) <-> 1(开灯) :  ");
        fgets(buf,sizeof(buf),stdin);
        buf[strlen(buf)-1] = '\0';
 
        //User -> 内核
        write(fd,buf,sizeof(buf));
    }
 
    /*
    //User -> 内核
    write(fd,buf,sizeof(buf));
 
    //内核 -> User
    read(fd,buf,sizeof(buf));
    */
 
    close(fd);
    return 0;
}

head.h

#ifndef __HEAD_H__
#define __HEAD_H__
#define PHY_RCC        0x50000A28
 
#define PHY_LED1_MODER 0x50006000
#define PHY_LED1_ODR   0x50006014
 
#define PHY_LED2_MODER 0x50007000
#define PHY_LED2_ODR   0x50007014
 
#define PHY_LED3_MODER 0x50006000
#define PHY_LED3_ODR   0x50006014
 
 
#endif