驱动开发day2

任务：使用模块化编译安装驱动实现三盏LED灯的亮灭

驱动程序

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

#define PHY_RCC 0X50000A28
#define PHY_LED1_MODER 0x50006000
#define PHY_LED2_MODER 0x50007000
#define PHY_LED1_ODR 0x50006014
#define PHY_LED2_ODR 0x50007014


unsigned int major;
char kbuf[128] = "";

unsigned int *vir_rcc;
unsigned int *vir_moder1;
unsigned int *vir_odr1;


unsigned int *vir_moder2;
unsigned int *vir_odr2;


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__);
    unsigned long ret;
    ret = copy_to_user(ubuf,kbuf,size);
    if(ret)
    {
        printk("copy_to_user_failed\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__);
    unsigned long ret;
    ret = copy_from_user(kbuf,ubuf,size);
    if(ret)
    {
        printk("copy_from_user_failed\n");
        return -EIO;  
    }   

    if(kbuf[0] == '0')
    {
        //关闭LED1灯
        printk("LED1 OFF\n");
        (*vir_odr1) &= (~(0x1 << 10));
    }
    else if(kbuf[0] == '1')
    {
        //打开LED1灯
        printk("LED1 ON\n");
        (*vir_odr1) |= (0x1 << 10);        
    }
	if(kbuf[1] == '0')
    {
        //关闭LED2灯
        printk("LED2 OFF\n");
        (*vir_odr2) &= (~(0x1 << 10));
    }
    else if(kbuf[1] == '1')
    {
        //打开LED2灯
        printk("LED2 ON\n");
        (*vir_odr2) |= (0x1 << 10);        
    }
    if(kbuf[2] == '0')
    {
        //关闭LED3灯
        printk("LED3 OFF\n");
        (*vir_odr1) &= (~(0x1 << 8));
    }
    else if(kbuf[2] == '1')
    {
        //打开LED3灯
        printk("LED3 ON\n");
        (*vir_odr1) |= (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)
{
    major = register_chrdev(0,"mydev",&fops);
    if(major < 0)
    {
        printk("字符设备注册失败\n");
        return major;
    }
    else
    {
        printk("字符设备注册成功,major=%d\n",major);
    }

    //物理地址映射到虚拟地址上
    vir_rcc = ioremap(PHY_RCC,4);
    if(vir_rcc == NULL)
    {
        printk("映射失败 : %d\n",__LINE__);
        return -EFAULT;
    }
	//LED1/3
    vir_moder1 = ioremap(PHY_LED1_MODER,4);
    if(vir_moder1 == NULL)
    {
        printk("映射失败 : %d\n",__LINE__);
        return -EFAULT;
    }
    vir_odr1 = ioremap(PHY_LED1_ODR,4);
    if(vir_odr1 == NULL)
    {
        printk("映射失败 : %d\n",__LINE__);
        return -EFAULT;
    }
	//LED2
    vir_moder2 = ioremap(PHY_LED2_MODER,4);
    if(vir_moder2 == NULL)
    {
        printk("映射失败 : %d\n",__LINE__);
        return -EFAULT;
    }
    vir_odr2 = ioremap(PHY_LED2_ODR,4);
    if(vir_odr2 == NULL)
    {
        printk("映射失败 : %d\n",__LINE__);
        return -EFAULT;
    }
	printk("映射成功\n");

    //串口初始化
    (*vir_rcc) |= (0x3 << 4);
	//LED1初始化
    (*vir_moder1) &= (~(0x3 << 20));
    (*vir_moder1) |= (0x1 << 20);
	(*vir_odr1) &= (~(0x1 << 10));
	//LED2初始化
	(*vir_moder2) &= (~(0x3 << 20));
	(*vir_moder2) |= (0x1 << 20);
	(*vir_odr2) &= (~(0x1 << 10));

	//LED3初始化
	(*vir_moder1) &= (~(0x3 << 16));
	(*vir_moder1) |= (0x1 << 16);
	(*vir_odr1) &= (~(0x1 << 8));
	printk("LED初始化成功\n");

    return 0;
}

static void __exit mycdev_exit(void)
{
    //取消映射
    iounmap(vir_rcc);
    iounmap(vir_moder1);
    iounmap(vir_odr1);
    iounmap(vir_moder2);
    iounmap(vir_odr2);

    unregister_chrdev(major,"mydev");
}

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

应用程序

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



int main()
{
    int fd=open("/dev/mychrdev",O_RDWR);
    if(fd < 0)
    {
        printf("文件打开失败\n");
        return -1;
    }
    else
    {
        printf("文件打开成功\n");
    }
    char buf[128]="";
    while(1)
    {
    memset(buf,0,sizeof(buf));
    printf("请输入LED1/2/3的状态(1:ON/0:OFF)>>");
    fgets(buf,sizeof(buf),stdin);
    buf[strlen(buf)-1]='\0';
	if(buf[0]=='q')
	{
		break;
	}
    write(fd,buf,sizeof(buf));
    memset(buf,0,sizeof(buf));
	read(fd,buf,sizeof(buf));
    printf("buf : %s\n",buf);
    }
    close(fd);
    return 0;


}

串口现象：

开发板现象：