9.13 作业
通过字符设备驱动分布注册方式编写led驱动，完成设备文件和设备的绑定
mycdev.c
#include
#include
#include
#include
#include
#include
#include
#include
#include "head.h"
int major = 0;
int minor = 0;
int count = 3;
char *devname = "mycdev";
char buf[128] = {0};
unsigned int *rcc; // 存放rcc的地址
gpio_t *gpioe;
gpio_t *gpiof;
struct class *cls;
struct device *dev;
struct cdev *cdev;
void led_on_off(gpio_t *gpio, short pin, unsigned int flag)
{
switch (flag)
{
case LEDX_OFF:
gpio->ODR &= ~(1 << pin);
break;
case LEDX_ON:
gpio->ODR |= 1 << pin;
break;
case LEDX_REV:
gpio->ODR ^= 1 << pin;
break;
}
}
int my_register_chrdev(const struct file_operations *fops)
{
int flag;
dev_t d;
cdev = cdev_alloc();
if (cdev == NULL)
{
printk("申请字符设备驱动对象空间失败\n");
flag = EFAULT;
goto out1;
}
cdev_init(cdev, fops);
if (major)
{
flag = register_chrdev_region(MKDEV(major, minor), count, devname);
}
else
{
flag = alloc_chrdev_region(&d, minor, count, devname);
major = MAJOR(d);
minor = MINOR(d);
}
if (flag)
{
printk("申请设备号失败\n");
goto out2;
}
flag = cdev_add(cdev, MKDEV(major, minor), count);
if (flag)
{
printk("注册驱动失败\n");
goto out3;
}
return 0;
out3:
unregister_chrdev_region(MKDEV(major, minor), count);
out2:
kfree(cdev);
out1:
return flag;
}
void my_unregister_chrdev(void)
{
cdev_del(cdev);
unregister_chrdev_region(MKDEV(major, minor), count);
kfree(cdev);
}
int mycdev_open(struct inode *inode, struct file *file)
{
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
file->private_data = (void *)MINOR(inode->i_rdev);
return 0;
}
ssize_t mycdev_read(struct file *file, char *ubuf, size_t size, loff_t *lof)
{
long ref;
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
ref = copy_to_user(ubuf, buf, size > sizeof(buf) ? size : sizeof(buf));
if (ref)
{
printk("copy_to_user err\n");
return -EIO;
}
return ref;
}
ssize_t mycdev_write(struct file *file, const char *ubuf, size_t size, loff_t *lof)
{
long ref;
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
ref = copy_from_user(buf, ubuf, size > sizeof(buf) ? size : sizeof(buf));
if (ref)
{
printk("copy_from_user err\n");
return -EIO;
}
return ref;
}
long mycdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
int min;
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
min = (int)file->private_data;
if (minor == min)
{
led_on_off(gpioe, 10, cmd);
}
else if (minor + 1 == min)
{
led_on_off(gpiof, 10, cmd);
}
else if (minor + 2 == min)
{
led_on_off(gpioe, 8, cmd);
}
return 0;
}
int mycdev_close(struct inode *inode, struct file *file)
{
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
return 0;
}
struct file_operations fops = {
.open = mycdev_open,
.read = mycdev_read,
.write = mycdev_write,
.unlocked_ioctl = mycdev_ioctl,
.release = mycdev_close,
};
static int __init mycdev_init(void)
{
int flag,i,j;
// 注册
flag = my_register_chrdev(&fops);
if (flag < 0)
{
printk("注册失败\n");
goto out1;
}
printk("success major=%d\n", major);
// 物理内存映射
rcc = ioremap(RCC, 4);
flag = -EFAULT;
if (!rcc)
{
printk("物理内存映射失败%d\n", __LINE__);
goto out2;
}
gpioe = ioremap(GPIOE, sizeof(gpio_t));
if (!gpioe)
{
printk("物理内存映射失败%d\n", __LINE__);
goto out3;
}
gpiof = ioremap(GPIOF, sizeof(gpio_t));
if (!gpiof)
{
printk("物理内存映射失败%d\n", __LINE__);
goto out4;
}
// 使能
*rcc |= 3 << 4;
gpioe->MODER &= ~(3 << 20);
gpioe->MODER |= 1 << 20;
gpioe->MODER &= ~(3 << 16);
gpioe->MODER |= 1 << 16;
gpiof->MODER &= ~(3 << 20);
gpiof->MODER |= 1 << 20;
cls = class_create(THIS_MODULE, devname);
if (IS_ERR(cls))
{
printk("向上提交目录失败\n");
flag = -PTR_ERR(cls);
goto out5;
}
printk("向上提交目录成功\n");
for (i = 0; i < 3; i++)
{
dev = device_create(cls, NULL, MKDEV(major, minor + i), NULL, "%s%d", devname, minor + i);
if (IS_ERR(cls))
{
printk("向上提交设备节点失败\n");
flag = -PTR_ERR(cls);
goto out6;
}
}
printk("向上提交设备节点成功\n");
return 0;
out6:
for (j = 0; j < i; j++)
{
device_destroy(cls, MKDEV(major, minor + j));
}
class_destroy(cls);
out5:
iounmap(gpiof);
out4:
iounmap(gpioe);
out3:
iounmap(rcc);
out2:
my_unregister_chrdev();
out1:
return flag;
}
static void __exit mycdev_exit(void)
{
int i;
for (i = 0; i < count; i++)
{
device_destroy(cls, MKDEV(major, minor + i));
}
class_destroy(cls);
// 取消物理内存映射
iounmap(rcc);
iounmap(gpiof);
iounmap(gpioe);
// 取消注册
my_unregister_chrdev();
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL"); head.h
#ifndef __HEAD_H__
#define __HEAD_H__
#define RCC 0x50000a28
typedef struct{
unsigned int MODER;
unsigned int OTYPER;
unsigned int OSPEEDR;
unsigned int PUPDR;
unsigned int IDR;
unsigned int ODR;
}gpio_t;
#define GPIOE 0x50006000
#define GPIOF 0x50007000
#define LEDX_ON _IO('l',1)
#define LEDX_OFF _IO('l',0)
#define LEDX_REV _IO('l',2)
#endiftest.c
#include
#include
#include
#include
#include
#include
#include
#include
#include "head.h"
int main()
{
char buf[128] = {0};
int fd0 = open("/dev/mycdev0", O_RDWR);
int fd1 = open("/dev/mycdev1", O_RDWR);
int fd2 = open("/dev/mycdev2", O_RDWR);
if (fd0 < 0|fd1 < 0|fd2 < 0)
{
printf("文件打开失败\n");
return -1;
}
int t;
while (1)
{
ioctl(fd0, LEDX_REV);
sleep(1);
ioctl(fd0, LEDX_REV);
sleep(1);
ioctl(fd1, LEDX_REV);
sleep(1);
ioctl(fd1, LEDX_REV);
sleep(1);
ioctl(fd2, LEDX_REV);
sleep(1);
ioctl(fd2, LEDX_REV);
sleep(1);
}
close(fd0);
close(fd1);
close(fd2);
return 0;
}