头文件代码
#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
//功能码
#define LED_ON _IOW('l',1,int)
#define LED_OFF _IOW('l',0,int)
#endif
应用层代码
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <sys/ioctl.h>
#include "head.h"
int main(int argc, char const *argv[])
{
char buf[128] = {0};
int a, b;
int fd;
while (1)
{
// 从终端读取
printf("请输入要打开哪个设备>");
printf("0:LED1 1:LED2 2:LED3\n");
printf("请输入>");
scanf("%d", &b);
if (b == 0)
{
fd = open("/dev/mycdev0", O_RDWR);
}
else if (b == 1)
{
fd = open("/dev/mycdev1", O_RDWR);
}
else if (b == 2)
{
fd = open("/dev/mycdev2", O_RDWR);
}
if (fd < 0)
{
printf("打开设备文件失败\n");
exit(-1);
}
printf("请输入指令\n");
printf("0(关灯) 1(开灯)\n");
printf("请输入>");
scanf("%d", &a);
switch (a)
{
case 1:
ioctl(fd, LED_ON); // 开灯
break;
case 0:
ioctl(fd, LED_OFF);
break;
}
close(fd);
}
return 0;
}
驱动代码
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/device.h>
#include <linux/uaccess.h>
#include<linux/slab.h>
#include<linux/cdev.h>
#include "head.h"
dev_t devid;
struct cdev *cdev;
unsigned int major = 500;
unsigned int minor = 0;
gpio_t *vir_led1;
gpio_t *vir_led2;
gpio_t *vir_led3;
unsigned int *vir_rcc;
struct class *cls;
struct device *dev;
int mycdev_open(struct inode *inode, struct file *file)
{
//获取当前设备文件对应的设备号
int which_dev = inode->i_rdev;
//将次设备号保存到当前文件的file结构中
file->private_data = (void *)MINOR(which_dev);
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
return 0;
}
long mycdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
unsigned int which_dev = (unsigned int)file->private_data;
switch(which_dev)
{
case 0:
//LED1控制逻辑；
if(cmd == LED_ON)
{
vir_led1->ODR |= (0x1 << 10); // LED1开灯
}
else if(cmd == LED_OFF)
{
vir_led1->ODR &= (~(0X1 << 10));
}
break;
case 1:
//LED2控制逻辑；
if(cmd == LED_ON)
{
vir_led2->ODR |= (0x1 << 10); // LED2开灯
}
else if(cmd == LED_OFF)
{
vir_led2->ODR &= (~(0X1 << 10));
}
break;
case 2:
//LED3控制逻辑；
if(cmd == LED_ON)
{
vir_led3->ODR |= (0x1 << 8); // LED3开灯
}
else if(cmd == LED_OFF)
{
vir_led3->ODR &= (~(0X1 << 8));
}
break;
}
return 0;
}
ssize_t mycdev_read(struct file *file, char *ubuf, size_t size, loff_t *lof)
{
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)
{
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;
}
// 定义操作方法风扇结构体变量并赋值
struct file_operations fops = {
.open = mycdev_open,
.unlocked_ioctl = mycdev_ioctl,
.release = mycdev_close,
.read = mycdev_read,
.write = mycdev_write,
};
// 灯的寄存器映射以及初始化
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("灯的寄存器初始化成功\n");
return 0;
}
static int __init mycdev_init(void)
{
int ret;
// 1.申请对象空间 cdev_alloc
cdev = cdev_alloc();
if (cdev == NULL)
{
printk("申请驱动对象空间失败\n");
ret = -EFAULT;
goto OUT1;
}
printk("申请驱动对象空间成功\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()
// 动态申请
if (major == 0)
{
ret = alloc_chrdev_region(&devid, minor, 3, "mycdev");
if (ret != 0)
{
printk("动态申请设备号失败\n");
goto OUT2;
}
//统一后面的操作
major = MAJOR(devid); //根据设备号获取主设备号
minor = MINOR(devid);
}
//静态指定申请
else
{
ret = register_chrdev_region(MKDEV(major,minor),3,"mycdev");
if(ret != 0)
{
printk("静态指定设备号失败\n");
goto OUT2;
}
}
printk("申请设备号成功\n");
// 4.注册驱动对象 cdev_add()
ret = cdev_add(cdev, MKDEV(major,minor), 3);
if (ret != 0)
{
printk("注册设备驱动对象失败\n");
goto OUT3;
}
printk("注册设备驱动对象成功\n");
// 5.向上提交目录 class_create()
cls = class_create(THIS_MODULE, "mycdev");
if (IS_ERR(cls))
{
printk("向上提交目录失败\n");
goto OUT4;
}
printk("向上提交目录成功\n");
// 6.向上提交设备信息 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("向上提交设备节点信息失败\n");
goto OUT5;
}
printk("向上提交设备节点信息成功\n");
// 灯的寄存器映射以及初始化
all_led_init();
return 0;
OUT5:
//将提交成功的设备信息销毁
for(--i;i>=0;i--)
{
device_destroy(cls,MKDEV(major,i));
}
OUT4:
class_destroy(cls);
OUT3:
unregister_chrdev_region(MKDEV(major,minor), 3);
OUT2:
kfree(cdev);
OUT1:
return ret;
}
static void __exit mycdev_exit(void)
{
// 取消地址映射
iounmap(vir_led1);
iounmap(vir_led2);
iounmap(vir_rcc);
// 1.销毁设备信息 device_destroy
int i;
for(i=0;i<3;i++)
{
device_destroy(cls,MKDEV(major,i));
}
// 2.销毁目录 class_destroy
class_destroy(cls);
// 3.注销驱动对象 cdev_del
cdev_del(cdev);
// 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);
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");
