驱动 day4

通过字符设备驱动分步注册方式编写LED灯的驱动，应用程序使用ioctl函数编写硬件控制

mycdev.c

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

char kbuf[128] = {0};
gpio_t *vir_led1;
gpio_t *vir_led2;
gpio_t *vir_led3;
unsigned int *vir_rcc;
struct class *cls;
struct device *dev;
struct cdev *cdev;
unsigned int major=0;
unsigned int minor=0;
dev_t devno;
int mycdev_open(struct inode *inode, struct file *file)
{
    printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
    return 0;
}
long mycdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
    int which;
    int ret=copy_from_user(&which,(unsigned int *)arg,4);
    if(ret)
    {
        printk("copy_from_user err\n");
        return ret;
    }
    // 根据用户空间功能码的不同实现硬件不同的控制
    switch (cmd)
    {
    case LED_ON: // 开灯
        switch (which)
        {
        case 1: // LED1
            vir_led1->ODR |= (0X1 << 10);
            break;
        case 2: // LED2
            vir_led2->ODR |= (0X1 << 10);
            break;
        case 3: // LED3
            vir_led3->ODR |= (0X1 << 8);
            break;
        }
        break;
    case LED_OFF: // 关灯
        switch (which)
        {
        case 1:
            vir_led1->ODR &= (~(0X1 << 10));
            break;
        case 2:
            vir_led2->ODR &= (~(0X1 << 10));
            break;
        case 3:
            vir_led3->ODR &= (~(0X1 << 8));
            break;
        }
        break;
    }
    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并赋值
struct file_operations fops = {

    .open = mycdev_open,
    .unlocked_ioctl = mycdev_ioctl,
    .release = mycdev_close,
};

int all_led_init(void)
{
    // 寄存器地址的映射
    vir_led1 = ioremap(PHY_LED1_ADDR, sizeof(gpio_t));
    if (vir_led1 == NULL)
    {
        printk("ioremap failed：%d\n", __LINE__);
        return -ENOMEM;
    }
    vir_led2 = ioremap(PHY_LED2_ADDR, sizeof(gpio_t));
    if (vir_led2 == NULL)
    {
        printk("ioremap failed：%d\n", __LINE__);
        return -ENOMEM;
    }
    vir_led3 = vir_led1;
    vir_rcc = ioremap(PHY_RCC_ADDR, 4);
    if (vir_rcc == NULL)
    {
        printk("ioremap failed：%d\n", __LINE__);
        return -ENOMEM;
    }
    printk("物理地址映射成功\n");
    // 寄存器的初始化
    // rcc
    (*vir_rcc) |= (3 << 4);
    // led1
    vir_led1->MODER &= (~(3 << 20));
    vir_led1->MODER |= (1 << 20);
    vir_led1->ODR &= (~(1 << 10));
    // led2
    vir_led2->MODER &= (~(3 << 20));
    vir_led2->MODER |= (1 << 20);
    vir_led2->ODR &= (~(1 << 10));
    // led3
    vir_led3->MODER &= (~(3 << 16));
    vir_led1->MODER |= (1 << 16);
    vir_led1->ODR &= (~(1 << 8));
    printk("寄存器初始化成功\n");
    return 0;
}

static int __init mycdev_init(void)
{
	int ret;
	dev_t denvo;
	//1、分配字符设备驱动对象
	cdev = cdev_alloc();
	if(cdev == NULL)
	{
		printk("申请字符设备驱动对象失败\n");
		ret = -EFAULT;
		goto OUT1;
	}
	printk("申请字符设备驱动成功\n");
	//2、初始化字符设备驱动对象
	cdev_init(cdev,&fops);
	//3、申请设备号
	if(major > 0)//静态指定
	{
		ret = register_chrdev_region(MKDEV(major,minor),3,"mycdev");
		if(ret)
		{
			printk("静态指定设备号失败\n");
			goto OUT2;
		}
	}
	else
	{
		ret = alloc_chrdev_region(&devno,minor,3,"mycdev");
		if(ret)
		{
			printk("静态指定设备号失败\n");
			goto OUT2;
		}
		minor =
			MINOR(devno);//根据设备号获取次设备号
		major = MAJOR(devno);//根据设备号获取主设备号
	}
	printk("申请设备号成功");
	//4、注册字符设备驱动对象
	ret = cdev_add(cdev,MKDEV(major,minor),3);
	if(ret)
	{
		printk("注册字符设备驱动对象失败\n");
		goto OUT3;
	}
	printk("注册字符设备驱动对象成功");
	//向上提交目录
	cls = class_create(THIS_MODULE,"mycdev");
	if(IS_ERR(cls))
	{
		printk("向上提交目录失败\n");
		ret = -PTR_ERR(cls);
		goto OUT4;
	}
	printk("向上提交目录成功\n");
	//向上提交设备节点信息
	int i;
	for(i=0;i<3;i++)
	{
		dev=device_create(cls,NULL,MKDEV(major,i),NULL,"mycdev%d",i);
		if(IS_ERR(dev))
		{
			printk("向上提交设备节点信息失败\n");
			ret = -PTR_ERR(dev);
			goto OUT5;
		}
	}
	printk("向上提交设备节点成功\n");
	all_led_init();
    return 0;
OUT5:
	for(--i;i>=0;i--)
	{
		device_destroy(cls,MKDEV(major,i));//释放提交成功的设备信息
	}
	class_destroy(cls);//销毁目录
OUT4:
	cdev_del(cdev);
OUT3:
	unregister_chrdev_region(MKDEV(major,minor),3);
OUT2:
	kfree(cdev);
OUT1:
	return ret;
}
static void __exit mycdev_exit(void)
{
    // 取消地址映射
    iounmap(vir_led1);
    iounmap(vir_led2);
    iounmap(vir_rcc);

    // 销毁设备信息
    int i;
    for (i=0;i<3;i++)
    {
        device_destroy(cls,MKDEV(major,i));
    }
    // 销毁目录信息
    class_destroy(cls);
	//销毁字符设备驱动
	cdev_del(cdev);
	//释放设备号
	unregister_chrdev_region(MKDEV(major,minor),3);
	//释放对象空间
	kfree(cdev);
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");

head.h

#ifndef __HEAD_H__
#define __HEAD_H__ 
typedef struct{
    unsigned int MODER;
    unsigned int OTYPER;
    unsigned int OSPEEDR;
    unsigned int PUPDR;
    unsigned int IDR;
    unsigned int ODR;
}gpio_t;
#define PHY_LED1_ADDR 0X50006000
#define PHY_LED2_ADDR 0X50007000
#define PHY_LED3_ADDR 0X50006000
#define PHY_RCC_ADDR  0X50000A28

#define LED_ON _IOW('l',1,int) //开灯
#define LED_OFF _IOW('l',0,int)//关灯

#endif 

test.c

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

int main(int argc, char const *argv[])
{
    char buf[128]={0};
    int a,b;
    int fd=open("/dev/mycdev0",O_RDWR);
    if(fd<0)
    {
        printf("打开设备文件失败\n");
        exit(-1);
    }
    while(1)
    {
        printf("请输入要实现的功能：1（开灯）0（关灯>）");
        scanf("%d",&a);
        printf("请输入要控制的灯：1（LED1） 2(LED2) 3(LED3)>");
        scanf("%d",&b);
        switch(a)
        {
            case 1:
                ioctl(fd,LED_ON,&b);
                break;
            case 0:
                ioctl(fd,LED_OFF,&b);
                break;
        }
    }

    
    close(fd);

    return 0;
}