驱动开发 day4 9/13

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

//构建LED开关的功能码，不添加ioctl第三个参数
#define LED_ON _IO('l',1)
#define LED_OFF _IO('l',0)

#endif 

test.c

#include "head.h"
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <sys/ioctl.h>


int main(int argc, char const *argv[])
{
    int a;
    char buf[128] = {0};
    int fd = open("/dev/myled0", O_RDWR);
    if (fd < 0)
    {
        printf("打开设备文件失败\n");
        exit(-1);
    }
    while (1)
    {
        // 从终端读取
        printf("请输入对LED灯的控制:1(开灯)0(关灯)>");
        scanf("%d", &a);
        switch (a)
        {
        case 1:
            ioctl(fd, LED_ON); // 开灯
            break;
        case 0:
            ioctl(fd, LED_OFF); // 关灯
        }
    }

    close(fd);

    return 0;
}

mychrdev.c

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/slab.h>
#include "head.h"

gpio_t *vir_led1;
gpio_t *vir_led2;
gpio_t *vir_led3;
unsigned int *vir_rcc;
struct cdev *cdev;
char kbuf[128] = {0};
unsigned int major = 0;
unsigned int minor = 0;
dev_t devno;
module_param(major, uint, 0664); // 方便在命令行传递major的值
struct class *cls;
struct device *dev;

// 封装操作方法
int mycdev_open(struct inode *inode, struct file *file)
{
    int min = MINOR(inode->i_rdev); // 根据打开的文件对应的设备号获取次设备号
    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;
    switch (min)
    {
    case 0: // 控制LED1
        switch (cmd)
        {
        case LED_ON:
            // 开灯
            vir_led1->ODR |= 1 << 10;
            break;
        case LED_OFF:
            // 关灯
            vir_led1->ODR &= (~(1 << 10));
            break;
        }
        break;
    case 1: // 控制LED2
        switch (cmd)
        {
        case LED_ON:
            // 开灯
            vir_led2->ODR |= 1 << 10;
            break;
        case LED_OFF:
            // 关灯
            vir_led2->ODR &= (~(1 << 10));
            break;
        }
        break;
    case 2: // 控制LED3
        switch (cmd)
        {
        case LED_ON:
            // 开灯
            vir_led3->ODR |= 1 << 10;
            break;
        case LED_OFF:
            // 关灯
            vir_led3->ODR &= (~(1 << 10));
            break;
        }
        break;
    }
    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,
    .unlocked_ioctl = mycdev_ioctl,
    .release = mycdev_close,
};

int all_led_init(void);

static int __init mycdev_init(void)
{
    int ret;
    // 字符设备注册
    // 1.申请驱动对象
    cdev = cdev_alloc();
    if (cdev == NULL)
    {
        printk("申请对象空间失败！\n");
        ret = -EFAULT;
        goto out1;
    }
    printk("申请对象成功！\n");
    // 2.初始化驱动对象
    cdev_init(cdev, &fops);
    printk("初始化对象成功！\n");

    // 3.申请主设备号和一定数量设备资源
    if (major > 0) // 静态指定设备号
    {
        ret = register_chrdev_region(MKDEV(major, minor), 3, "myled");
        if (ret)
        {
            printk("静态申请设备号失败！\n");
            goto out2;
        }
    }
    else if (major == 0) // 动态申请设备号
    {
        ret = alloc_chrdev_region(&devno, 0, 3, "myled");
        if (ret)
        {
            printk("动态申请设备号失败！\n");
            goto out2;
        }
        major = MAJOR(devno); // 获取主设备号
        minor = MINOR(devno); // 获取此设备号
    }
    printk("申请设备号成功！\n");

    // 4.根据申请的设备号和驱动对象注册驱动
    ret = cdev_add(cdev, MKDEV(major, minor), 3);
    if (ret)
    {
        printk("驱动注册失败！\n");
        goto out3;
    }
    printk("注册驱动成功！\n");

    // 5.向上提交目录信息
    cls = class_create(THIS_MODULE, "myled");
    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");

    // 6.向上提交设备信息文件
    int i;
    for (i = 0; i < 3; i++)
    {
        dev = device_create(cls, NULL, MKDEV(major, i), NULL, "myled%d", i);
        if (IS_ERR(dev))
        {
            printk("向上提交设备信息失败！\n");
            ret = -PTR_ERR(dev);
            goto out5;
        }
    }
    printk("向上提交设备信息文件成功！\n");

    // 寄存器映射以及初始化
    all_led_init();
    return 0;
out5:
    for (--i; i > -1; i--)
    {
        device_destroy(cls, MKDEV(major, i));
    }
    class_destroy(cls);
out4:
    cdev_del(cdev);
out3:
    unregister_chrdev_region(MKDEV(major, minor), 3);
out2:
    kfree(cdev);
out1:
    return ret;
}
static void __exit mycdev_exit(void)
{
    int i;
    for (i = 0; i < 3; i++)
    {
        device_destroy(cls, MKDEV(major, i));
    }
    class_destroy(cls);
    cdev_del(cdev);
    unregister_chrdev_region(MKDEV(major, minor), 3);
    kfree(cdev);
}

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) |= (0X3 << 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_led3->MODER |= (1 << 16);
    vir_led3->ODR &= (~(1 << 8));
    printk("寄存器初始化成功\n");

    return 0;
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");