驱动开发day1 - 技术栈

头文件

cs 复制代码

#ifndef __HEAD_H__
#define __HEAD_H__
#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

#define PHY_RCC        0X50000A28

#endif

demo1.c

cs 复制代码

#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]={};
//定义指针指向映射后的虚拟内存
unsigned int *vir_moder1;
unsigned int *vir_odr1;
unsigned int *vir_moder2;
unsigned int *vir_odr2;
unsigned int *vir_moder3;
unsigned int *vir_odr3;
unsigned int *vir_rcc;

//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;
        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__);
        int ret;
        ret=copy_from_user(kbuf, ubuf,size);
        if(ret)
        {
                printk("copy_from_user filed\n");
                return -EIO;  
        }
        if (kbuf[1] == '0')
        {
                // 关灯逻辑
				if (kbuf[0] == '1')
                	(*vir_odr1) &= (~(0X1<<10));
				else if (kbuf[0] == '2')
                	(*vir_odr2) &= (~(0X1<<10));
				else if (kbuf[0] == '3')
                	(*vir_odr3) &= (~(0X1<<8));
        }
        else if (kbuf[1] == '1')
        {
                // 开灯逻辑
				if (kbuf[0] == '1')
                	(*vir_odr1) |= (0X1<<10);
				else if (kbuf[0] == '2')
					(*vir_odr2) |= (0X1<<10);
				else if (kbuf[0] == '3')
                	(*vir_odr3) |= (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,
};

//入口函数，安装内核模块时执行
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");
        }
        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_moder1 = ioremap(PHY_LED1_MODER, 4);
        if (vir_moder1 == NULL)
        {
                printk("物理内存地址映射失败%d\n", __LINE__);
                return -EFAULT;
        }
        vir_odr1 = ioremap(PHY_LED1_ODR, 4);
        if (vir_odr1 == NULL)
        {
                printk("物理内存地址映射失败%d\n", __LINE__);
                return -EFAULT;
        }
        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 -EFAULT;
        }
        printk("寄存器内存映射成功\n");

        //LED1寄存器初始化
        (*vir_rcc) |= (0X3<<4);//GPIOE控制器时钟使能
        (*vir_moder1) &= (~(0X3<<20));//MODER[21:20]->00
        (*vir_moder1) |= (0X1<<20);//MODER[21:20]->01
        (*vir_odr1) &= (~(0X1<<10));//默认关灯

        vir_moder2 = ioremap(PHY_LED2_MODER, 4);
        if (vir_moder2 == NULL)
        {
                printk("物理内存地址映射失败%d\n", __LINE__);
                return -EFAULT;
        }
        vir_odr2 = ioremap(PHY_LED2_ODR, 4);
        if (vir_odr2 == NULL)
        {
                printk("物理内存地址映射失败%d\n", __LINE__);
                return -EFAULT;
        }
        //LED2
        (*vir_moder2) &= (~(0X3<<20));//MODER[21:20]->00
        (*vir_moder2) |= (0X1<<20);//MODER[21:20]->01
        (*vir_odr2) &= (~(0X1<<10));//默认关灯

        vir_moder3 = ioremap(PHY_LED3_MODER, 4);
        if (vir_moder3 == NULL)
        {
                printk("物理内存地址映射失败%d\n", __LINE__);
                return -EFAULT;
        }
        vir_odr3 = ioremap(PHY_LED3_ODR, 4);
        if (vir_odr3 == NULL)
        {
                printk("物理内存地址映射失败%d\n", __LINE__);
                return -EFAULT;
        }
        //LED3
        (*vir_moder3) &= (~(0X3<<16));//MODER[21:20]->00
        (*vir_moder3) |= (0X1<<16);//MODER[21:20]->01
        (*vir_odr3) &= (~(0X1<<8));//默认关灯

        return 0;
}

//出口函数，卸载内核模块时执行
static void __exit mycdev_exit(void)
{
        //取消内存映射
        iounmap(vir_moder1);
        iounmap(vir_odr1);

        iounmap(vir_moder2);
        iounmap(vir_odr2);

        iounmap(vir_moder3);
        iounmap(vir_odr3);

        iounmap(vir_rcc);
	//注销字符设备驱动
        unregister_chrdev(major,"mychrdev");
}

//用于声明入口函数
module_init(mycdev_init);
//用于声明出口函数
module_exit(mycdev_exit);
//声明当前内核模块遵循GPL协议
MODULE_LICENSE("GPL");

text.c

cs 复制代码

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
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");
        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';

        //调用write
        write(fd, buf, sizeof(buf));
        //memset(buf, 0, sizeof(buf));
        //read(fd, buf, sizeof(buf));
        //printf("buf:%s\n",buf);
    }
    //调用close
    close(fd);
    return 0;
}