分步注册字符设备驱动

头文件

#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_LED_GPIOE 0x50006000
#define PHY_LED_GPIOF 0x50007000
#define PHY_LED_RCC 0X50000A28

#define LED_ON _IOW('1',1,int)
#define LED_OFF _IOW('0',0,int)


#endif

驱动文件

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

unsigned int major = 0;
unsigned int minor = 0;
char kbuf[128] = {0};
gpio_t *gpioe10;
gpio_t *gpiof10;
gpio_t *gpioe8;
unsigned int *vir_rcc;

struct class *clz;
struct device *dev;
struct cdev *cdev;
dev_t devno;

int myDev_open(struct inode *major, struct file *file)
{
    printk("%s:%s,%d\n", __FILE__, __func__, __LINE__);
    return 0;
}

ssize_t myDev_write(struct file *file, const char *ubuf, size_t size, loff_t *lof)
{
    int ret;
    ret = copy_from_user(kbuf, ubuf, size);
    if (ret)
    {
        printk("copy_from_user failed!\n");
        return ret;
    }
    return 0;
}

ssize_t myDev_read(struct file *file, char *ubuf, size_t size, loff_t *lof)
{
    int ret;
    ret = copy_to_user(ubuf, kbuf, size);
    if (ret)
    {
        printk("copy_to_user failed!\n");
        return ret;
    }
    return 0;
}

int myDev_close(struct inode *major, struct file *file)
{
    printk("myDev_close\n");
    return 0;
}
long myDev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
    printk("%s:%s,%d\n", __FILE__, __func__, __LINE__);
    switch (cmd)
    {
    case LED_ON:
        switch (arg)
        {
        case 1:
            gpioe10->ODR |= (0x1 << 10);
            break;
        case 2:
            gpiof10->ODR |= (0x1 << 10);
            break;
        case 3:
            gpioe8->ODR |= (0x1 << 8);
            break;
        default:
            break;
        }
        break;
    case LED_OFF:
        switch (arg)
        {
        case 1:
            gpioe10->ODR &= (~(0x1 << 10));
            break;
        case 2:
            gpiof10->ODR &= (~(0x1 << 10));
            break;
        case 3:
            gpioe8->ODR &= (~(0x1 << 8));
            break;
        default:
            break;
        }
        break;
    default:
        break;
    }

    return 0;
}
struct file_operations fop = {
    .open = myDev_open,
    .release = myDev_close,
    .read = myDev_read,
    .write = myDev_write,
    .unlocked_ioctl = myDev_ioctl};

int myLedInit(void)
{
    gpioe10 = ioremap(PHY_LED_GPIOE, sizeof(gpio_t));
    if (gpioe10 == NULL)
    {
        printk("内存映射失败%d\n", __LINE__);
        return -EFAULT;
    }
    gpiof10 = ioremap(PHY_LED_GPIOF, sizeof(gpio_t));
    if (gpiof10 == NULL)
    {
        printk("内存映射失败%d\n", __LINE__);
        return -EFAULT;
    }
    gpioe8 = gpioe10;
    vir_rcc = ioremap(PHY_LED_RCC, 4);
    if (vir_rcc == NULL)
    {
        printk("内存映射失败%d\n", __LINE__);
        return -EFAULT;
    }
    // pe10
    gpioe10->MODER &= (~(0x3 << 20));
    gpioe10->MODER |= (0x1 << 20);
    // pe8
    gpioe8->MODER &= (~(0x3 << 16));
    gpioe8->MODER |= (0x1 << 16);
    // pf10
    gpiof10->MODER &= (~(0x3 << 20));
    gpiof10->MODER |= (0x1 << 20);

    (*vir_rcc) |= (0x1 << 4);
    (*vir_rcc) |= (0x1 << 5);

    (gpioe10->ODR) &= (~(0x1 << 10));
    gpioe8->ODR &= (~(0x1 << 8));
    gpiof10->ODR &= (~(0x1 << 10));
    return 0;
}

static int __init mydev_init(void)
{
    int i = 0;
    int ret;
    cdev = cdev_alloc();
    if (cdev == NULL)
    {
        printk("申请设备对象失败\n");
        return -EFAULT;
    }
    printk("申请设备对象成功\n");
    cdev_init(cdev, &fop);
    if (major > 0)
    {
        // 静态申请
        ret = register_chrdev_region(MKDEV(major, minor), 3, "mydev");
        if (ret)
        {
            printk("静态指定设备号失败\n");
            goto OUT2;
        }
    }
    else
    {
        ret = alloc_chrdev_region(&devno, minor, 3, "mydev");
        if (ret)
        {
            printk("动态申请设备号失败\n");
            goto OUT2;
        }
        major = MAJOR(devno);
        minor = MINOR(devno);
    }
    printk("申请设备号成功\n");
    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("设备注册成功！major=%d\n", major);
    clz = class_create(THIS_MODULE, "mydev");
    if (IS_ERR(clz))
    {
        printk("向上提交目录失败\n");
        ret = -PTR_ERR(clz);
        goto OUT4;
    }
    printk("向上提交目录成功\n");
    for (i = 0; i < 3; i++)
    {
        dev = device_create(clz, NULL, MKDEV(major, i), NULL, "mydev%d", i);
        if (IS_ERR(dev))
        {
            printk("向上提交设备节点信息失败\n");
            ret = -PTR_ERR(clz);
            goto OUT5;
        }
    }
    printk("向上提交设备节点信息成功\n");
    myLedInit();
    return 0;
OUT5:
    for (--i; i >= 0; i--)
    {
        device_destroy(clz, MKDEV(major, i));
    }
    class_destroy(clz);
OUT4:
    cdev_del(cdev);
OUT3:
    unregister_chrdev_region(MKDEV(major, minor), 0);
OUT2:
    kfree(cdev);
OUT1:
    return ret;
}

static void __exit mydev_exit(void)
{
    printk("mydev_exit\n");
    iounmap(gpioe10);
    iounmap(vir_rcc);
    iounmap(gpiof10);
    int i;
    for (i = 0; i < 3; i++)
    {
        device_destroy(clz, MKDEV(major, i));
    }
    class_destroy(clz);
    cdev_del(cdev);
    unregister_chrdev_region(MKDEV(major, minor), 3);
    kfree(cdev);
}

module_init(mydev_init);
module_exit(mydev_exit);
MODULE_LICENSE("GPL");

测试文件

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

int main()
{
    char buf[128];
    int fd = open("/dev/mydev0", O_RDWR);
    if (fd < 0)
    {
        perror("open failed!\n");
        exit(-1);
    }
    int a, b;
    printf("打开设备成功！\n");
    while (1)
    {
        printf("请输入led灯的逻辑》1(开灯)0(关灯)\n");
        scanf("%d", &a);
        printf("请输入控制的灯:1(LED1) 2(LED2) 3(LED3)\n");
        scanf("%d", &b);
        switch (a)
        {
        case 1:
            ioctl(fd, LED_ON, b);
            break;
        case 0:
            ioctl(fd, LED_OFF, b);
            break;
        default:
            break;
        }
    }
    close(fd);
    return 0;
}