驱动开发day4

通过字符设备驱动的分步实现编写LED驱动，另外实现设备文件和驱动的绑定

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
// 构建开灯关灯的功能码
#define LED_ON _IO('l', 1)
#define LED_OFF _IO('l', 0)
#endif

test.c

#include<stdlib.h>
#include<stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include<unistd.h>
#include<string.h>
#include "head.h"int main(int argc, char const *argv[])
{char buf[128]={0};int a,b;int fd=open("/dev/mycdev1",O_RDWR);if(fd<0){printf("打开设备文件失败\n");exit(-1);}while(1){//从终端读取printf("请输入要实现的功能 ");printf("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;
}

mycdev.c

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/slab.h>
#include <linux/uaccess.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 class *cls;
struct device *dev;
struct cdev *cdev;
unsigned int major = 0;
unsigned int minor = 0;
dev_t devno;int mycdev_open(struct inode *inode, struct file *file)
{//获取打开文件的次设备号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)
{//获取文件的次设备号int min = (int)file->private_data;switch (min){case 0://操作LED1switch(cmd){case LED_ON:(vir_led1->ODR) |= (0x1 << 10);//led1开灯break;case LED_OFF:(vir_led1->ODR) &= (~(0x1 << 10));//LED1关灯break;}break;case 1://操作LED2switch(cmd){case LED_ON:(vir_led2->ODR) |= (0x1 << 10);//led2开灯break;case LED_OFF:(vir_led2->ODR) &= (~(0x1 << 10));//LED2关灯break;}break;case 2://操作LED3switch(cmd){case LED_ON:(vir_led3->ODR) |= (0x1 << 10);//led3开灯break;case LED_OFF:(vir_led3->ODR) &= (~(0x1 << 10));//LED3关灯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");// 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)
{int ret;// 1.申请一个对象空间 cdev_alloccdev = cdev_alloc();if (cdev == NULL){printk("申请字符设备驱动对象失败");ret = -EFAULT;goto cont1;}printk("字符设备驱动对象申请成功\n");// 2.初始化对象 cdev_initcdev_init(cdev, &fops);// 3.申请设备号 register_chrdev_region()/alloc_chrdev_region()if (major == 0) // 动态申请模拟{ret = alloc_chrdev_region(&devno, minor, 3, "mychrdev");if (ret){printk("动态申请设备号失败\n");goto cont2;}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 // 静态申请模拟{ret = register_chrdev_region(MKDEV(major, minor), 3, "mychrdev");if (ret){printk("静态指定设备号失败\n");goto cont2;}}printk("设备号申请成功\n");// 4.注册驱动对象 cdev_addret = cdev_add(cdev, MKDEV(major, minor), 3);if (ret){printk("注册驱动对象失败\n");goto cont3;}printk("注册字符设备驱动对象成功\n");// 5.向上提交目录 class_createcls = class_create(THIS_MODULE, "mychrdev");if (IS_ERR(cls)){printk("向上提交目录失败\n");goto cont4;}printk("向上提交目录成功\n");// 6.向上提交设备节点信息 device_createint 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");goto cont5;}}printk("向上提交设备节点信息成功\n");// 寄存器映射以及初始化all_led_init();return 0;
cont5:// 将提交成功的节点信息释放for (--i; i > 0; i--){device_destroy(cls, MKDEV(major, i));}// 销毁目录class_destroy(cls);
cont4:cdev_del(cdev);
cont3:unregister_chrdev_region(MKDEV(major, minor), 3);
cont2:kfree(cdev);
cont1:return ret;}
static void __exit mycdev_exit(void)
{// 取消地址映射iounmap(vir_led1);iounmap(vir_led2);iounmap(vir_rcc);// 1.销毁设备节点信息int i;for (i = 0; i < 3; i++){device_destroy(cls, MKDEV(major, i));}// 2.销毁目录class_destroy(cls);// 3.注销字符设备驱动对象cdev_del(cdev);// 4.释放设备号unregister_chrdev_region(MKDEV(major, minor), 3);// 5.释放申请到的字符设备驱动对象空间kfree(cdev);
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");