驱动开发 day4

通过字符设备驱动分步注册方式编写LED驱动,完成设备文件和设备的绑定

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 _IO('l', 1)  //开灯
#define LED_OFF _IO('l', 0) //关灯

#endif 

demo.c

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

struct class *cls;
struct device *dev;
int major;
char kbuf[128] = {0};
gpio_t *vir_led1;
gpio_t *vir_led2;
gpio_t *vir_led3;
unsigned int *vir_rcc;

int mycdev_open(struct inode *inode, struct file *file)
{
    int min = MINOR(inode->i_rdev);
    file->private_data = (void *)min;
    printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
    return 0;
}

long mycdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
    int min = (int)file->private_data;

    // 进行功能控制
    switch (min)
    {
    case 0:
        switch (cmd)
        {
        case LED_ON: // 开灯
            vir_led1->ODR |= (0x1 << 10);
            break;
        case LED_OFF: // 关灯
            vir_led1->ODR &= (~(0X1 << 10));
            break;
        }
        break;

    case 1:
        switch (cmd)
        {
        case LED_ON: // 开灯
            vir_led2->ODR |= (0x1 << 10);
            break;
        case LED_OFF: // 关灯
            vir_led2->ODR &= (~(0X1 << 10));
            break;
        }
        break;

    case 2:
        switch (cmd)
        {
        case LED_ON: // 开灯
            vir_led3->ODR |= (0x1 << 8);
            break;
        case LED_OFF: // 关灯
            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 filed：%d\n", __LINE__);
        return -ENOMEM;
    }
    vir_led2 = ioremap(PHY_LED2_ADDR, sizeof(gpio_t));
    if (vir_led2 == NULL)
    {
        printk("ioremap filed：%d\n", __LINE__);
        return -ENOMEM;
    }
    vir_led3 = vir_led1;
    vir_rcc = ioremap(PHY_RCC_ADDR, 4);
    if (vir_rcc == NULL)
    {
        printk("ioremap filed：%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 i;
    // 字符设备驱动注册
    major = register_chrdev(0, "mychrdev", &fops);
    if (major < 0)
    {
        printk("字符设备驱动注册失败\n");
        return major;
    }
    printk("字符设备驱动注册成功:major=%d\n", major);
    // 向上提交目录
    cls = class_create(THIS_MODULE, "mychrdev");
    if (IS_ERR(cls))
    {
        printk("向上提交目录失败\n");
        return -PTR_ERR(cls);
    }
    // 向上提交设备节点信息
    // 为三盏灯创建三个设备文件
    for (i = 0; i < 3; i++)
    {
        dev = device_create(cls, NULL, MKDEV(major, i), NULL, "mychrdev%d", i);
        if (IS_ERR(dev))
        {
            printk("向上提交设备节点信息失败\n");
            return -PTR_ERR(dev);
        }
    }
    // 寄存器映射以及初始化
    all_led_init();

    return 0;
}
static void __exit mycdev_exit(void)
{
    int i;
    // 取消地址映射
    iounmap(vir_led1);
    iounmap(vir_led2);
    iounmap(vir_rcc);
    // 销毁设备节点信息
    for (i = 0; i < 3; i++)
    {
        device_destroy(cls, MKDEV(major, i));
    }
    // 销毁目录信息
    class_destroy(cls);
    // 注销字符设备驱动
    unregister_chrdev(major, "mychrdev");
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");

text.c

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

int main(int argc, char const *argv[])
{
    int a, b, fd;
    int result;
    char buf[128] = {0};

    while (1)
    {
        printf("请选择要实现的功能\n");
        printf("0(关灯) 1(开灯) 2(退出)>");
        scanf("%d", &a);

        if (a == 2)
        {
            break; // 用户选择退出
        }

        // 清空输入缓冲区
        while ((getchar()) != '\n');

        if (a != 0 && a != 1)
        {
            printf("无效的选择，请重新输入。\n");
            continue; // 用户输入无效，重新循环
        }

        printf("请输入要控制的灯\n");
        printf("1(LED1) 2(LED2) 3(LED3)>");
        scanf("%d", &b);

        if (b < 1 || b > 3)
        {
            printf("无效的选择，请重新输入。\n");
            continue; // 用户输入无效，重新循环
        }

        // 清空输入缓冲区
        while ((getchar()) != '\n');

        // 定义设备文件路径
        char devicePath[20];
        sprintf(devicePath, "/dev/mychrdev%d", b - 1);

        // 打开设备文件
        fd = open(devicePath, O_RDWR);
        if (fd < 0)
        {
            perror("打开设备文件失败");
            exit(-1);
        }

        // 控制LED
        if (a == 1)
            result = ioctl(fd, LED_ON);
        else if (a == 0)
            result = ioctl(fd, LED_OFF);

        if (result == -1)
            perror("ioctl error");

        close(fd);
    }

    return 0;
}