驱动代码:
#include
#include
#include
#include
#include
#include
#include
#include
#include "head.h"
gpio_t *vir_led1;
gpio_t *vir_led2;
gpio_t *vir_led3;
unsigned int *vir_rcc;
struct cdev *cdev;
struct class *cls;
struct device *dev;
unsigned int major = 500;
unsigned int minor = 0; //此设备的起始值
dev_t devno;
char kbuf[128] = {0};
// 封装操作方法
int mycdev_open(struct inode *inode, struct file *file)
{
int a = inode->i_rdev; //获取当前设备文件对应的设备号
file->private_data = (void *)MINOR(a); //将次设备号保存到当前文件的file结构中
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
return 0;
}
long mycdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
unsigned int a = (unsigned int)file->private_data;
switch (a)
{
case 0:
switch (cmd)
{
case LED_ON:
vir_led1->ODR |= (0x1 << 10); // 开灯
break;
case LED_OFF:
vir_led1->ODR &= (~(0x1 << 10));
break;
}
break;
case 1:
switch (cmd)
{
case LED_ON:
vir_led2->ODR |= (0x1 << 10); // 开灯
break;
case LED_OFF:
vir_led2->ODR &= (~(0x1 << 10));
break;
}
break;
case 2:
switch (cmd)
{
case LED_ON:
vir_led3->ODR |= (0x1 << 8); // 开灯
break;
case LED_OFF:
vir_led3->ODR &= (~(0x1 << 8));
break;
}
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__);
if (size > sizeof(kbuf)) //用户的需求内核满足不了
{
size = sizeof(kbuf);
}
long ret;
ret = copy_to_user(ubuf, kbuf, size);
if (ret)
{
printk("copy_to_user filed\n");
return -EIO;
}
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__);
if (size > sizeof(kbuf)) //用户的需求内核满足不了
{
size = sizeof(kbuf);
}
long ret;
ret = copy_from_user(kbuf, ubuf, size);
if (ret)
{
printk("copy_from_user filed\n");
return -EIO;
}
return 0;
}
int mycdev_close(struct inode *inode, struct file *file)
{
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
return 0;
}
//定义一个操作方法结构体变量并且初始化
struct file_operations fops = {
.open = mycdev_open,
.read = mycdev_read,
.write = mycdev_write,
.release = mycdev_close,
.unlocked_ioctl = mycdev_ioctl,
};
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_led3->MODER |= (1 << 16);
vir_led3->ODR &= (~(1 << 8));
printk("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("申请对象空间失败\n");
ret = -EFAULT;
goto OUT1;
}
// 2.初始化对象 cdev_init
cdev_init(cdev, &fops);
// 3.s申请设备号 register_chrdev_region()/alloc_chrdev_region()
if (major == 0)
{
//动态申请
ret = alloc_chrdev_region(&devno, minor, 3, "mycdev");
if (ret)
{
printk("动态申请设备号失败\n");
goto OUT2;
}
//统一后面的操作
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
ret = register_chrdev_region(MKDEV(major, minor), 3, "mycdev");
if (ret)
{
printk("静态指定设备号失败\n");
goto OUT2;
}
}
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("注册设备驱动对象失败\n");
goto OUT3;
}
// 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");
ret = -PTR_ERR(cls);
goto OUT4;
}
// 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("向上提交设备节点失败\n");
ret = -PTR_ERR(dev);
goto OUT5;
}
}
printk("向上提交设备节点成功\n");
// 寄存器映射以及初始化
all_led_init();
return 0;
OUT5:
for (--i; i >= 0; 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)
{
// 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");
应用层代码:
#include
#include
#include
#include
#include
#include
#include
#include
#include "head.h"
int main(int argc, char const *argv[])
{
int a, b, fd0, fd1, fd2;
while (1)
{
printf("请输入要控制的灯 1(LED1) 2(LED2) 3(LED3):");
scanf("%d", &b);
fd0 = open("/dev/mycdev0", O_RDWR);
if (fd0 < 0)
{
printf("打开设备文件失败\n");
exit(-1);
}
fd1 = open("/dev/mycdev1", O_RDWR);
if (fd1 < 0)
{
printf("打开设备文件失败\n");
exit(-1);
}
fd2 = open("/dev/mycdev2", O_RDWR);
if (fd2 < 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:
switch (b)
{
case 1:
ioctl(fd0, LED_ON); //开灯
break;
case 2:
ioctl(fd1, LED_ON);
break;
case 3:
ioctl(fd2, LED_ON);
break;
}
break;
case 0:
switch (b)
{
case 1:
ioctl(fd0, LED_OFF); //关灯
break;
case 2:
ioctl(fd1, LED_OFF);
break;
case 3:
ioctl(fd2, LED_OFF);
break;
}
break;
}
}
close(fd0);
close(fd1);
close(fd2);
return 0;
}
头文件:
#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