驱动day4作业

通过字符设备驱动的分步实现编写LED驱动，另外实现特备文件和设备的绑定

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 

demo1.c

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/cdev.h>
#include "head.h"char kbuf[128]={0};
gpio_t *vir_led1;
gpio_t *vir_led2;
gpio_t *vir_led3;
unsigned int *vir_rcc;
struct cdev *cdev;
dev_t devno;
unsigned int major=0;
unsigned int minor=0;
struct class *cls;
struct device *dev;
int mycdev_open(struct inode *inode, struct file *file)
{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 arg)
{int min=(int)file->private_data;switch(min){case 0:switch (cmd){case LED_ON:vir_led1->ODR |= (0x1 << 10);break;case LED_OFF:vir_led1->ODR &= (~(0X1 << 10));break;}break;case 1:switch (cmd){case LED_ON:vir_led2->ODR |= (0X1 << 10);break;case LED_OFF:vir_led2->ODR &= (~(0X1 << 10));break;}break;case 2:switch (cmd){case LED_ON:vir_led3->ODR |= (0X1 << 8);break;case LED_OFF:vir_led3->ODR &= (~(0X1 << 8));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并赋值
struct file_operations fops={.open=mycdev_open,.unlocked_ioctl=mycdev_ioctl,.release=mycdev_close,
};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);//led1vir_led1->MODER &= (~(3<<20));vir_led1->MODER |= (1<<20);vir_led1->ODR &= (~(1<<10));//led2vir_led2->MODER &= (~(3<<20));vir_led2->MODER |= (1<<20);vir_led2->ODR &= (~(1<<10));//led3vir_led3->MODER &= (~(3<<16));vir_led1->MODER |= (1<<16);vir_led1->ODR &= (~(1<<8));printk("寄存器初始化成功\n");return 0;
}static int __init mycdev_init(void)
{//字符设备驱动注册int ret;cdev=cdev_alloc();if(cdev == NULL){printk("申请对象失败\n");ret=-EFAULT;goto out1;}printk("申请对象成功\n");cdev_init(cdev,&fops);if(major == 0){ret = alloc_chrdev_region(&devno,minor,3,"mychrdev");if(ret){printk("申请设备号失败\n");goto out2;}printk("申请设备号成功\n");major=MAJOR(devno);minor=MINOR(devno);}ret=cdev_add(cdev,MKDEV(major,minor),3);if(ret){printk("注册对象失败\n");goto out3;}printk("注册对象成功\n");cls=class_create(THIS_MODULE,"mychrdev");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");int i;for(i=0;i<3;i++){dev=device_create(cls,NULL,MKDEV(major,i),NULL,"myled%d",i);if(IS_ERR(dev)){printk("向上提交设备节点失败\n");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);int i;for(i=0;i<3;i++){device_destroy(cls,MKDEV(major,i));}class_destroy(cls);//注销字符设备驱动cdev_del(cdev);unregister_chrdev_region(MKDEV(major,minor),3);kfree(cdev);
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");

text.c

#include<stdlib.h>
#include<stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include<unistd.h>
#include<string.h>
#include "head.h"int main(int argc, char const *argv[])
{int fd;char name[20]={0};int a,b;while(1){printf("请选择要控制的灯：1（LED1）2(LED2) 3(LED3)\n");printf("请输入>");scanf("%d",&b);switch(b){case 1:strcpy(name,"/dev/myled0");break;case 2:strcpy(name,"/dev/myled1");break;case 3:strcpy(name,"/dev/myled2");break;}fd=open(name,O_RDWR);if(fd<0){printf("打开设备文件失败\n");exit(-1);}//从终端读取printf("请输入要实现的功能:0(关灯) 1(开灯)\n");printf("请输入>");scanf("%d",&a);switch(a){case 1:ioctl(fd,LED_ON);break;case 0:ioctl(fd,LED_OFF);break;}}close(fd);return 0;
}