Linux内核驱动开发板的灯的实验

头文件

#ifndef __HEAD_H__
#define __HEAD_H__
 
#define PHY_LED1_MODER 0X50006000
#define PHY_LED1_ODR   0X50006014
#define PHY_RCC        0X50000A28


#define PHY_LED2_MODER 0X50007000
#define PHY_LED2_ODR 0x50007014
 
#define PHY_LED3_MODER 0X50006000
#define PHY_LED3_ODR 0x50006014

 
#endif

驱动程序

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include "head.h"
int major; // 用于保存主设备号
char kbuf[128] = {0};
unsigned int *vir_led1_moder;
unsigned int *vir_led1_odr;
unsigned int *vir_rcc;
unsigned int *vir_led2_moder;
unsigned int *vir_led2_odr;
unsigned int *vir_led3_moder;
unsigned int *vir_led3_odr;
// 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;
    if (sizeof(kbuf) < size)
        size = sizeof(kbuf);
    ret = copy_to_user(ubuf, kbuf, size);
    if (ret)
    {
        printk("copy_tO_user filed\n");
        return -EIO;
    }
    printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
    return 0;
}
ssize_t mycdev_write(struct file *file, const char *ubuf, size_t size, loff_t *lof)
{
    int ret;
    if (sizeof(kbuf) < size) // 判断用户空间的需求是否能被驱动满足，满足不了就给能给的最好的
        size = sizeof(kbuf);
    ret = copy_from_user(kbuf, ubuf, size);
    if (ret)
    {
        printk("copy_from_user filed\n");
        return -EIO;
    }
    // led1
    if (kbuf[0] == '1') // 开灯
    {
        // 开灯逻辑
        (*vir_led1_odr) |= (0x1 << 10);
    }
    else if (kbuf[0] == '0') // 关灯
    {
        // 关灯
        (*vir_led1_odr) &= (~(0x1 << 10));
    }
    // led2
    if (kbuf[1] == '1') // 开灯
    {
        // 开灯逻辑
        (*vir_led2_odr) |= (0x1 << 10);
    }
    else if (kbuf[1] == '0') // 关灯
    {
        // 关灯
        (*vir_led2_odr) &= (~(0x1 << 10));
    }
    // led3
    if (kbuf[3] == '1') // 开灯
    {
        // 开灯逻辑
        (*vir_led3_odr) |= (0x1 << 8);
    }
    else if (kbuf[3] == '0') // 关灯
    {
        // 关灯
        (*vir_led3_odr) &= (~(0x1 << 8));
    }
    printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
    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完成初始化
struct file_operations fops =
    {
        .open = mycdev_open,
        .read = mycdev_read,
        .write = mycdev_write,
        .release = mycdev_close,
};

static int __init mycdev_init(void)
{
    // 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);
    // 映射物理寄存器
    vir_led1_moder = ioremap(PHY_LED1_MODER, 4);
    if (vir_led1_moder == NULL)
    {
        printk("MODER寄存器地址映射表失败\n");
        return -EFAULT;
    }
    vir_led1_odr = ioremap(PHY_LED1_ODR, 4);
    if (vir_led1_odr == NULL)
    {
        printk("ODR寄存器地址映射表失败\n");
        return -EFAULT;
    }
    vir_rcc = ioremap(PHY_RCC, 4);
    if (vir_rcc == NULL)
    {
        printk("RCC寄存器地址映射表失败\n");
        return -EFAULT;
    }
    vir_led2_moder = ioremap(PHY_LED2_MODER, 4);
    if (vir_led2_moder == NULL)
    {
        printk("MODER寄存器地址映射表失败\n");
        return -EFAULT;
    }
    vir_led2_odr = ioremap(PHY_LED2_ODR, 4);
    if (vir_led2_odr == NULL)
    {
        printk("ODR寄存器地址映射表失败\n");
        return -EFAULT;
    }
    vir_led3_moder = ioremap(PHY_LED3_MODER, 4);
    if (vir_led3_moder == NULL)
    {
        printk("MODER寄存器地址映射表失败\n");
        return -EFAULT;
    }
    vir_led3_odr = ioremap(PHY_LED3_ODR, 4);
    if (vir_led3_odr == NULL)
    {
        printk("ODR寄存器地址映射表失败\n");
        return -EFAULT;
    }
    printk("寄存器地址映射成功\n");
    // 寄存器初始化
    (*vir_rcc) |= (0x1 << 4); // rcc使能
    (*vir_rcc) |= (0x1 << 5);
    (*vir_led1_moder) &= (~(0X3 << 20)); // 设置为输出
    (*vir_led1_moder) |= (0x1 << 20);
    (*vir_led1_odr) &= (~(0x1 << 10));   // 灭灯
    (*vir_led2_moder) &= (~(0X3 << 20)); // 设置为输出
    (*vir_led2_moder) |= (0x1 << 20);
    (*vir_led2_odr) &= (~(0x1 << 10));   // 灭灯
    (*vir_led3_moder) &= (~(0X3 << 16)); // 设置为输出
    (*vir_led3_moder) |= (0x1 << 16);
    (*vir_led3_odr) &= (~(0x1 << 8)); // 灭灯
    printk("硬件寄存器初始化成功\n");
    return 0;
}
static void __exit mycdev_exit(void)
{
    // 取消寄存器地址映射
    iounmap(vir_led1_moder);
    iounmap(vir_led1_odr);
    iounmap(vir_led2_moder);
    iounmap(vir_led2_odr);
    iounmap(vir_led3_moder);
    iounmap(vir_led3_odr);
    iounmap(vir_rcc);
    // 字符设备驱动的注销
    unregister_chrdev(major, "mychrdev");
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");

应用程序

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
int main(int argc, char const *argv[])
{
    char buf[128] = {0};
    int fd = open("/dev/mychrdev", O_RDWR);
    if (fd < 0)
    {
        printf("打开设备文件失败\n");
        exit(-1);
    }
    while (1)
    {
        printf("输入控制命令--->三位>");
        fgets(buf, sizeof(buf), stdin);
        buf[strlen(buf) - 1] = '\0';
        write(fd, buf, sizeof(buf));
    }
    close(fd);
    return 0;
}

开发板的结果