作业1
题目：
编写LED灯的驱动，创建三个设备文件，每个设备文件和一个LED灯绑定，当操作这个设备文件时只能控制设备文件对应的这盏灯。
代码：
main.c
#include "head.h"
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>int main(int argc, char const *argv[])
{int dev_selected;int opt_selected;int led_fds[3];int back;int quit;// 开led_fds[0] = open("/dev/my_led0", O_RDWR);if (led_fds[0] < 0) {printf("打开设备文件失败\n");exit(-1);}led_fds[1] = open("/dev/my_led1", O_RDWR);if (led_fds[1] < 0) {printf("打开设备文件失败\n");exit(-1);}led_fds[2] = open("/dev/my_led2", O_RDWR);if (led_fds[2] < 0) {printf("打开设备文件失败\n");exit(-1);}while (1) {quit = 0;printf("请选择要控制的设备\n");printf("1.LED1\n");printf("2.LED2\n");printf("3.LED3\n");printf("4.退出\n");scanf("%d", &dev_selected);switch (dev_selected) {case 1:case 2:case 3:while (1) {back = 0;printf("请选择操作 1.开 2.关 3.返回\n");scanf("%d", &opt_selected);switch (opt_selected) {case 1:ioctl(led_fds[dev_selected - 1], LED_ON);break;case 2:ioctl(led_fds[dev_selected - 1], LED_OFF);break;case 3:back = 1;break;}if (back)break;}break;case 4:quit = 1;break;default:printf("非法输入， 请重写输入\n");break;}if (quit)break;}// 关for (int i = 0; i < 3; i++)close(led_fds[i]);return 0;
}
led.c
#include "led.h"
#include "head.h"static int step_regist(void);
static int mapping_register(void);
static int all_led_init(void);// 虚拟地址
static gpio_t *vir_led1;
static gpio_t *vir_led2;
static gpio_t *vir_led3;
static unsigned int *vir_rcc;struct cdev *cdev_ptr; // 字符设备驱动对象
dev_t devno; // 设备号
int major = 500; // 主设备号
int minor = 0; // 次设备号
struct class *cls_ptr; // 提交目录
struct device *dev_prt; // 设备节点信息/*** @brief 安装驱动*/
static int __init led_init(void)
{int ret;// 映射 LED 寄存器地址if (!mapping_register())printk("寄存器地址映射成功\n");// 初始化 LED 寄存器if (!all_led_init())printk("寄存器初始化成功\n");// 分步注册设备驱动ret = step_regist();if (!ret)printk("分步注册设备驱动成功\n");return ret;
}/*** @brief 卸载驱动*/
static void __exit led_exit(void)
{// 1.销毁设备信息 device_destroyint i;for (i = 0; i < 3; i++) {device_destroy(cls_ptr, MKDEV(major, i));}// 2.销毁目录 class_destroyclass_destroy(cls_ptr);// 3.注销对象 cdev_del()cdev_del(cdev_ptr);// 4.释放设备号 unregister_chrdev_region()unregister_chrdev_region(MKDEV(major, minor), 3);// 5.释放对象空间 kfree()kfree(cdev_ptr);
}// 开
int led_open(struct inode *inode, struct file *file)
{// 传递次设备号到file的private_data成员file->private_data = (void *)MINOR(inode->i_rdev);return 0;
}
// 关
int led_close(struct inode *inode, struct file *file)
{return 0;
}
// GPIO控制
long led_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{unsigned int dev_selected = (int)(file->private_data + 1);switch (dev_selected) {case 1:(*vir_led1).odr ^= (0x1 << 10);break;case 2:(*vir_led2).odr ^= (0x1 << 10);break;case 3:(*vir_led3).odr ^= (0x1 << 8);break;}return 0;
}/*** @brief 分步注册*/
static int step_regist(void)
{int ret, i;// 1.分配字符设备驱动对象空间cdev_ptr = cdev_alloc();if (cdev_ptr == NULL) {printk("申请字符设备驱动对象空间失败\n");ret = -EFAULT;goto out;}// 2.字符设备驱动对象部分初始化cdev_init(cdev_ptr, &fops);// 3.申请设备号if (major > 0) { // 指定设备号ret = register_chrdev_region(MKDEV(major, minor), 3, "my_led");if (ret) {printk("静态指定设备号失败\n");goto out2;}} else { // 自动分配可用的设备号for (i = 0; i < 3; i++) {ret = alloc_chrdev_region(&devno, minor, i, "my_led");if (ret) {printk("动态指定设备号失败\n");goto out2;}}major = MAJOR(devno);minor = MINOR(devno);}// 4.注册字符设备驱动对象 cdev_addret = cdev_add(cdev_ptr, MKDEV(major, minor), 3);if (ret) {printk("注册字符设备驱动对象失败\n");goto out3;}// 5.向上提交目录 class_createcls_ptr = class_create(THIS_MODULE, "my_led");if (IS_ERR(cls_ptr)) {printk("向上提交目录失败\n");ret = -PTR_ERR(cls_ptr);goto out4;}// 6.向上提交设备节点for (i = 0; i < 3; i++) {dev_prt = device_create(cls_ptr, NULL, MKDEV(major, i), NULL, "my_led%d", i);if (IS_ERR(dev_prt)) {printk("向上提交节点信息失败\n");ret = -PTR_ERR(dev_prt);goto out5;}}return 0;out5:for (--i; i < 3; i--)device_destroy(cls_ptr, MKDEV(major, i));class_destroy(cls_ptr);
out4:cdev_del(cdev_ptr);
out3:unregister_chrdev_region(MKDEV(major, minor), 3);
out2:kfree(cdev_ptr);
out:return ret;
}/*** @brief 寄存器地址映射*/
static int mapping_register(void)
{// 映射寄存器vir_led1 = ioremap(PHY_LED1_ADDR, sizeof(gpio_t));if (!vir_led1) {printk("LED1 地址映射失败\n");return -EFAULT;}vir_led2 = ioremap(PHY_LED2_ADDR, sizeof(gpio_t));if (!vir_led2) {printk("LED2 地址映射失败\n");return -EFAULT;}vir_led3 = ioremap(PHY_LED3_ADDR, sizeof(gpio_t));if (!vir_led3) {printk("LED3 地址映射失败\n");return -EFAULT;}vir_rcc = ioremap(PHY_RCC, 4);if (vir_rcc == NULL) {printk("RCC 寄存器地址映射失败\n");return -EFAULT;}return 0;
}/*** @brief led初始化*/
static int all_led_init(void)
{// RCC初始化(*vir_rcc) |= (0x3 << 4);// led1(*vir_led1).moder &= (~(0X3 << 20));(*vir_led1).moder |= (0X1 << 20);(*vir_led1).otyper &= (~(0X1 << 10));(*vir_led1).ospeedr &= (~(0X3 << 20));(*vir_led1).pupdr &= (~(0X3 << 20));// led2(*vir_led2).moder &= (~(0X3 << 20));(*vir_led2).moder |= (0X1 << 20);(*vir_led2).otyper &= (~(0X1 << 10));(*vir_led2).ospeedr &= (~(0X3 << 20));(*vir_led2).pupdr &= (~(0X3 << 20));// led3(*vir_led3).moder &= (~(0X3 << 16));(*vir_led3).moder |= (0X1 << 16);(*vir_led3).otyper &= (~(0X1 << 8));(*vir_led3).ospeedr &= (~(0X3 << 16));(*vir_led3).pupdr &= (~(0X3 << 16));return 0;
}module_init(led_init);
module_exit(led_exit);
MODULE_LICENSE("GPL");
led.h
#ifndef _LED_H_
#define _LED_H_#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/ioctl.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/uaccess.h>// 开
int led_open(struct inode *inode, struct file *file);
// 关
int led_close(struct inode *inode, struct file *file);
// GPIO控制
long led_ioctl(struct file *file, unsigned int cmd, unsigned long arg);// 重写文件操作结构体
struct file_operations fops = {.open = led_open,.release = led_close,.unlocked_ioctl = led_ioctl,
};#endif //_LED_H_
head.h
#ifndef _HEAD_H_
#define _HEAD_H_// 定义寄存器组织结构体
typedef struct {unsigned int moder;unsigned int otyper;unsigned int ospeedr;unsigned int pupdr;unsigned int idr;unsigned int odr;
} gpio_t;// 物理基地址
#define PHY_RCC 0x50000A28
#define PHY_LED1_ADDR 0x50006000 // PE10
#define PHY_LED2_ADDR 0x50007000 // PF10
#define PHY_LED3_ADDR 0x50006000 // PE8// GPIO控制
#define LED_ON _IOW('l', 1, int) // 1开 2关
#define LED_OFF _IOW('l', 2, int)#endif //_HEAD_H_
