分步注册方式 编写驱动
作业：通过分步注册方式，编写LED灯驱动：（驱动文件mycdev.c 测试文件test.c 头文件head.h)
mycdev.c
#include
#include
#include
#include
#include
#include
#include
#include "head.h"
struct cdev *cdev;
unsigned int major=0;
unsigned int minor=0;
dev_t devno;
int major;
char kbuf[128] = {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)
{
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
return 0;
}
long mycdev_ioctl(struct file *file,unsigned int cmd, unsigned long arg)
{
int which;
int ret = copy_from_user(&which,(unsigned int *)arg,4);
if(ret)
{
printk("copy_from_user err\n");
return ret;
}
switch (cmd)
{
case LED_ON://which LED is turned on
switch(which)
{
case 1: //LED1
vir_led1->ODR |= (0x1 << 10);
break;
case 2: //LED2
vir_led2->ODR |= (0x1 << 10);
break;
case 3: //LED3
vir_led3->ODR |= (0x1 << 8);
break;
}
break;
case LED_OFF: //which LED is turned off
switch (which)
{
case 1:
vir_led1->ODR &= (~(0x1 << 10));
break;
case 2:
vir_led2->ODR &= (~(0X1 << 10));
break;
case 3:
vir_led3->ODR &= (~(0X1 << 8));
break;
}
break;
return 0;
}
}
int all_leds_init(void)
{
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("ioremap success\n");
// init regestors
(*vir_rcc) |= (3 << 4);
vir_led1->MODER &= (~(3 << 20));
vir_led1->MODER |= (1 << 20);
vir_led1->ODR &= (~(1 << 10));
vir_led2->MODER &= (~(3 << 20));
vir_led2->MODER |= (1 << 20);
vir_led1->MODER &= (~(3 << 16));
vir_led1->MODER |= (1 << 16);
vir_led1->ODR &= (~(1 << 8));
printk("init regestors success\n");
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__);
int ret;
ret=copy_to_user(ubuf,kbuf,size);
if(ret)
{
printk("copy_to_user filad\n");
return ret;
}
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,
.release=mycdev_close,
};
static int __init mycdev_init(void)
{
int ret;
//cdev allocate space
cdev=cdev_alloc();
if(cdev==NULL)
{
printk("cdev allocate space failed\n");
ret=-EFAULT;
goto OUT1;
}
printk("cdev allocate space success\n");
cdev_init(cdev,&fops);
if(major>0)
{
ret=register_chrdev_region(MKDEV(major,minor),3,"mycdev");
if(ret)
{
printk("apply for cdev Number failed\n");
goto OUT2;
}
}
else
{
ret=alloc_chrdev_region(&devno,minor,3,"mycdev");
if(ret)
{
printk("apply for cdev Number failed\n");
goto OUT2;
}
minor=MINOR(devno);//minor of cdev Number
major=MAJOR(devno);//major of cdev Number
}
printk("cdev Number:major=%d\n", major);
printk("apply for cdev Number success\n");
ret=cdev_add(cdev,MKDEV(major,minor),3);
if(ret)
{
printk("regest cdev failed\n");
goto OUT3;
}
printk("regest cdev sucess\n");
cls=class_create(THIS_MODULE,"mycdev");
if(IS_ERR(cls))
{
printk("submit catalog list failed\n");
ret=-PTR_ERR(cls);
goto OUT4;
}
printk("submit catalog list success\n");
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("submit cdev inod failed\n");
ret=-PTR_ERR(dev);
goto OUT5;
}
}
printk("submit cdev inod success\n");
all_leds_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)
{
iounmap(vir_led1);
iounmap(vir_led2);
iounmap(vir_rcc);
int i;
for(i=0;i<3;i++)
{
device_destroy(cls,MKDEV(major,i));
}
class_destroy(cls);
cdev_del(cdev);
unregister_chrdev_region(MKDEV(major,minor),3);
kfree(cdev);
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");
test.c
#include
#include
#include
#include
#include
#include
#include
#include
#include"head.h"
int main(int argc, char const *argv[])
{
char buf[128]={0};
int a,b;
int fd=open("/dev/mycdev0",O_RDWR);
if(fd<0)
{
printf("open cdev failed\n");
exit(-1);
}
while(1)
{
printf("turn on or turn off：1（on）0（off)>）");
scanf("%d",&a);
printf("select the LED：1（LED1） 2(LED2) 3(LED3)>");
scanf("%d",&b);
switch(a)
{
case 1:
ioctl(fd,LED_ON,&b);
break;
case 0:
ioctl(fd,LED_OFF,&b);
break;
}
}
close(fd);
return 0;
}
head.h
#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
#define LED_ON _IOW('l',1,int)
#define LED_OFF _IOW('l',0,int)
#endif