驱动开发 作业 day3 9/8

实现三盏灯点亮

head.h

#ifndef __HEAD_H__
#define __HEAD_H__

#define LED1_MODER 0X50006000
#define LED1_ODR  0x50006014
#define LED1_RCC  0x50000A28
#define LED2_MODER 0X50007000
#define LED2_ODR  0x50007014
#define LED2_RCC  0x50000A28
#define LED3_MODER 0X50006000
#define LED3_ODR  0x50006014
#define LED3_RCC  0x50000A28
#endif

mychrdev.c

#include 
#include 
#include 
#include 
#include 
#include "head.h"

unsigned int major;
char kbuf[128] = {0};
unsigned int *vir1_moder;
unsigned int *vir1_odr;
unsigned int *vir1_rcc;
unsigned int *vir2_moder;
unsigned int *vir2_odr;
unsigned int *vir2_rcc;
unsigned int *vir3_moder;
unsigned int *vir3_odr;
unsigned int *vir3_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)
{
	int ret;
	ret = copy_to_user(ubuf, kbuf, size);
	if (ret < 0)
	{
		printk("copy to user err\n");
		return -EIO;
	}
	return 0;
}
ssize_t mycdev_write(struct file *file, const char *ubuf, size_t size, loff_t *lof)
{
	int ret;
	ret = copy_from_user(kbuf, ubuf, size);
	if (ret < 0)
	{
		printk("copy to user err\n");
		return -EIO;
	}
	if (kbuf[0] == '1')

	{
		// 点亮led
		*vir1_odr |= (0x1 << 10);
		*vir2_odr |= (0x1 << 10);
		*vir3_odr |= (0x1 << 8);
	}
	else
	{
		// 熄灭led
		*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,
};

int add(int a, int b)
{
	return a + b;
}

EXPORT_SYMBOL_GPL(add);

// 入口函数　安装内核模块时执行
static int __init mycdev_init(void)
{
	major = register_chrdev(0, "mychrdev", &fops);
	if (major < 0)
	{
		printk("字符设备注册失败！\n");
		return 0;
	}
	printk("字符设备注册成功！%d\n", major);
	// 地址映射
	vir1_moder = ioremap(LED1_MODER, 4);
	if (vir1_moder == NULL)
	{
		printk("物理地址映射到虚拟地址失败！%d\n", __LINE__);
		return -EFAULT;
	}
	vir2_moder = ioremap(LED2_MODER, 4);
	if (vir2_moder == NULL)
	{
		printk("物理地址映射到虚拟地址失败！%d\n", __LINE__);
		return -EFAULT;
	}
	vir3_moder = ioremap(LED3_MODER, 4);
	if (vir3_moder == NULL)
	{
		printk("物理地址映射到虚拟地址失败！%d\n", __LINE__);
		return -EFAULT;
	}
	vir1_odr = ioremap(LED1_ODR, 4);
	if (vir1_odr == NULL)
	{
		printk("物理地址映射到虚拟地址失败！%d\n", __LINE__);
		return -EFAULT;
	}
	vir2_odr = ioremap(LED2_ODR, 4);
	if (vir2_odr == NULL)
	{
		printk("物理地址映射到虚拟地址失败！%d\n", __LINE__);
		return -EFAULT;
	}
	vir3_odr = ioremap(LED3_ODR, 4);
	if (vir3_odr == NULL)
	{
		printk("物理地址映射到虚拟地址失败！%d\n", __LINE__);
		return -EFAULT;
	}
	vir1_rcc = ioremap(LED1_RCC, 4);
	if (vir1_rcc == NULL)
	{
		printk("物理地址映射到虚拟地址失败！%d\n", __LINE__);
		return -EFAULT;
	}
	vir2_rcc = ioremap(LED2_RCC, 4);
	if (vir2_rcc == NULL)
	{
		printk("物理地址映射到虚拟地址失败！%d\n", __LINE__);
		return -EFAULT;
	}
	vir3_rcc = ioremap(LED3_RCC, 4);
	if (vir3_rcc == NULL)
	{
		printk("物理地址映射到虚拟地址失败！%d\n", __LINE__);
		return -EFAULT;
	}
	// rcc初始化
	*vir1_rcc |= (0x1 << 4);
	*vir2_rcc |= (0x1 << 5);
	*vir3_rcc |= (0x1 << 4);
	// gpio初始化
	*vir1_moder &= (~(0x3 << 20));
	*vir1_moder |= (0x1 << 20);
	*vir2_moder &= (~(0x3 << 20));
	*vir2_moder |= (0x1 << 20);
	*vir3_moder &= (~(0x3 << 16));
	*vir3_moder |= (0x1 << 16);
	// 默认关灯
	*vir1_odr &= (~(0x1 << 10));
	*vir2_odr &= (~(0x1 << 10));
	*vir3_odr &= (~(0x1 << 8));

	return 0;
}

// 出口函数　卸载内核模块执行
static void __exit mycdev_exit(void)
{
	// 取消映射
	iounmap(vir1_rcc);
	iounmap(vir1_moder);
	iounmap(vir1_odr);
	iounmap(vir2_rcc);
	iounmap(vir2_moder);
	iounmap(vir2_odr);
	iounmap(vir3_rcc);
	iounmap(vir3_moder);
	iounmap(vir3_odr);

	// 字符设备注销
	unregister_chrdev(major, "mychrdev");
	return;
}

// 用于声明当前内核模块入口函数的地址
module_init(mycdev_init);
// 用于声明当前内核模块出口函数的地址
module_exit(mycdev_exit);
// 声明当前内核模块遵循GPL协议
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/mychrdev", O_RDWR);
    if (fd < 0)
    {
        printf("设备文件打开失败\n");
        exit(-1);
    }
    while (1)
    {
        printf("请选择灯的状态(1)点亮 (0)熄灭\n");
        fgets(buf, sizeof(buf), stdin);
        buf[strlen(buf) - 1] = 0;
        write(fd, buf, sizeof(buf));      
    }
    close(fd);
    return 0;
}