头文件(head.h)
cs
#ifndef __HEAD_H__
#define __HEAD_H__
#define PHY_LED1_MODER 0x50006000
#define PHY_LED2_MODER 0x50007000
#define PHY_LED3_MODER 0x50006000
#define PHY_LED1_ODR 0x50006014
#define PHY_LED2_ODR 0x50007014
#define PHY_LED3_ODR 0x50006014
#define PHY_RCC 0x50000A28
//构建开灯关灯的功能码
#define LED_ON _IO('l',1)
#define LED_OFF _IO('l',0)
#endif
c文件:
cs
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include "head.h"
int main(int argc, char const *argv[])
{
char buf[128] = "";
int a;
int fd = open("/dev/mycdev1", O_RDWR);
if (fd < 0)
{
printf("打开设备文件失败\n");
return -1;
}
printf("打开设备文件成功\n");
while (1)
{
printf("请输入要进行的操作,0(关灯),1(开灯) >");
scanf("%d", &a);
switch (a)
{
case 1:
ioctl(fd, LED_ON);
break;
case 0:
ioctl(fd, LED_OFF);
break;
}
}
close(fd);
return 0;
}
cs
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include "head.h"
struct cdev *cdev;
unsigned int major = 0;
unsigned int minor = 0;
dev_t devno;
// 定义RCC控制器指针指向映射后的虚拟内存
unsigned int *vir_rcc;
// LED1定义两个指针指向映射后的虚拟内存
unsigned int *vir_moder_led1;
unsigned int *vir_odr_led1;
// LED2定义两个指针指向映射后的虚拟内存
unsigned int *vir_moder_led2;
unsigned int *vir_odr_led2;
// LED3定义两个指针指向映射后的虚拟内存
unsigned int *vir_moder_led3;
unsigned int *vir_odr_led3;
struct class *cls;
struct device *dev;
int mycdev_open(struct inode *inode, struct file *file)
{
// 获取打开的文件的次设备号
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 args)
{
// 获取文件的次设备号
int min = (int)file->private_data;
switch (min)
{
case 0://操作LED1
switch(cmd)
{
case LED_ON:
(*vir_odr_led1) |= (0x1 << 10); // LED1开灯
break;
case LED_OFF:
(*vir_odr_led1) &= (~(0x1 << 10)); // LED1关灯
break;
}
break;
case 1://操作LED2
switch(cmd)
{
case LED_ON:
(*vir_odr_led2) |= (0x1 << 10); // LED2开灯
break;
case LED_OFF:
(*vir_odr_led2) &= (~(0x1 << 10)); // LED2关灯
break;
}
break;
case 2://操作LED3
switch(cmd)
{
case LED_ON:
(*vir_odr_led3) |= (0x1 << 10); // LED3开灯
break;
case LED_OFF:
(*vir_odr_led3) &= (~(0x1 << 10)); // LED3关灯
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赋值
struct file_operations fops = {
.open = mycdev_open,
.unlocked_ioctl = mycdev_ioctl,
.release = mycdev_close,
};
static int __init mycdev_init(void)
{
int ret;
// 1.申请一个对象空间 cdev_alloc
cdev = cdev_alloc();
if (cdev == NULL)
{
printk("申请字符设备驱动对象失败");
ret = -EFAULT;
goto cont1;
}
printk("字符设备驱动对象申请成功\n");
// 2.初始化对象 cdev_init
cdev_init(cdev, &fops);
// 3.申请设备号 register_chrdev_region()/alloc_chrdev_region()
if (major == 0) // 动态申请模拟
{
ret = alloc_chrdev_region(&devno, minor, 3, "mychrdev");
if (ret)
{
printk("动态申请设备号失败\n");
goto cont2;
}
major = MAJOR(devno); // 根据设备号获取主设备号
minor = MINOR(devno); // 根据设备号获取次设备号
}
else // 静态申请模拟
{
ret = register_chrdev_region(MKDEV(major, minor), 3, "mychrdev");
if (ret)
{
printk("静态指定设备号失败\n");
goto cont2;
}
}
printk("设备号申请成功\n");
// 4.注册驱动对象 cdev_add
ret = cdev_add(cdev, MKDEV(major, minor), 3);
if (ret)
{
printk("注册驱动对象失败\n");
goto cont3;
}
printk("注册字符设备驱动对象成功\n");
// 5.向上提交目录 class_create
cls = class_create(THIS_MODULE, "mychrdev");
if (IS_ERR(cls))
{
printk("向上提交目录失败\n");
goto cont4;
}
printk("向上提交目录成功\n");
// 6.向上提交设备节点信息 device_create
int i;
for (i = 0; i < 3; i++)
{
dev = device_create(cls, NULL, MKDEV(major, i), NULL, "mycdev%d", i);
if (IS_ERR(dev))
{
printk("向上提交设备节点失败\n");
goto cont5;
}
}
printk("向上提交设备节点信息成功\n");
// RCC控制器地址映射
vir_rcc = ioremap(PHY_RCC, 4);
if (vir_rcc == NULL)
{
printk("物理内存地址映射失败%d\n", __LINE__);
return -1;
}
// LED1进行寄存器的地址映射
vir_moder_led1 = ioremap(PHY_LED1_MODER, 4);
if (vir_moder_led1 == NULL)
{
printk("物理内存地址映射失败%d\n", __LINE__);
return -1;
}
vir_odr_led1 = ioremap(PHY_LED1_ODR, 4);
if (vir_odr_led1 == NULL)
{
printk("物理内存地址映射失败%d\n", __LINE__);
return -1;
}
printk("LED1寄存器内存映射成功\n");
// LED2进行寄存器的地址映射
vir_moder_led2 = ioremap(PHY_LED2_MODER, 4);
if (vir_moder_led2 == NULL)
{
printk("物理内存地址映射失败%d\n", __LINE__);
return -1;
}
vir_odr_led2 = ioremap(PHY_LED2_ODR, 4);
if (vir_odr_led2 == NULL)
{
printk("物理内存地址映射失败%d\n", __LINE__);
return -1;
}
printk("LED2寄存器内存映射成功\n");
// LED3进行寄存器的地址映射
vir_moder_led3 = vir_moder_led1;
if (vir_moder_led3 == NULL)
{
printk("物理内存地址映射失败%d\n", __LINE__);
return -1;
}
vir_odr_led3 = vir_odr_led1;
if (vir_odr_led3 == NULL)
{
printk("物理内存地址映射失败%d\n", __LINE__);
return -1;
}
printk("LED3寄存器内存映射成功\n");
// RCC寄存器初始化
(*vir_rcc) |= (0x3 << 4); // GPIOE/GPIOF控制器时钟使能
// LED1寄存器初始化
(*vir_moder_led1) &= (~(0x3 << 20)); // MODER[21:20]->00
(*vir_moder_led1) |= (0x1 << 20); // MODER[21:20]->01
(*vir_odr_led1) &= (~(0x1 << 10)); // 默认关灯
// LED2寄存器初始化
(*vir_moder_led2) &= (~(0x3 << 20)); // MODER[21:20]->00
(*vir_moder_led2) |= (0x1 << 20); // MODER[21:20]->01
(*vir_odr_led2) &= (~(0x1 << 10)); // 默认关灯
// LED3寄存器初始化
(*vir_moder_led3) &= (~(0x3 << 16)); // MODER[17:16]->00
(*vir_moder_led3) |= (0x1 << 16); // MODER[17:16]->01
(*vir_odr_led3) &= (~(0x1 << 8)); // 默认关灯
return 0;
cont5:
// 将提交成功的节点信息释放
for (--i; i > 0; i--)
{
device_destroy(cls, MKDEV(major, i));
}
// 销毁目录
class_destroy(cls);
cont4:
cdev_del(cdev);
cont3:
unregister_chrdev_region(MKDEV(major, minor), 3);
cont2:
kfree(cdev);
cont1:
return ret;
}
static void __exit mycdev_exit(void)
{
// 取消RCC控制器内存映射
iounmap(vir_rcc);
// 取消LED1内存映射
iounmap(vir_moder_led1);
iounmap(vir_odr_led1);
// 取消LED2内存映射
iounmap(vir_moder_led2);
iounmap(vir_odr_led2);
// 1.销毁设备节点信息
int i;
for (i = 0; i < 3; i++)
{
device_destroy(cls, MKDEV(major, i));
}
// 2.销毁目录
class_destroy(cls);
// 3.注销字符设备驱动对象
cdev_del(cdev);
// 4.释放设备号
unregister_chrdev_region(MKDEV(major, minor), 3);
// 5.释放申请到的字符设备驱动对象空间
kfree(cdev);
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");