[驱动开发]字符设备驱动应用——点灯

点亮开发板stm32mp157的三盏灯

//头文件
#ifndef __LED_H__
#define __LED_H__//封装GPIO寄存器                                
typedef struct {                          volatile unsigned int MODER;   // 0x00volatile unsigned int OTYPER;  // 0x04volatile unsigned int OSPEEDR; // 0x08volatile unsigned int PUPDR;   // 0x0Cvolatile unsigned int IDR;     // 0x10volatile unsigned int ODR;     // 0x14
}gpio_t;//宏定义基地址
#define PHY_LED1_ADDR 0x50006000
#define PHY_LED2_ADDR 0x50007000
#define PHY_LED3_ADDR 0x50006000
#define PHY_RCC 0x50000A28#endif

//应用程序
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>int main(int argc, const char *argv[])
{char buf[128]={0};int fd = open("/dev/mychrdev",O_RDWR);if(fd < 0){printf("打开设备文件失败\n");exit(-1);}while(1){bzero(buf,sizeof(buf));printf("选择LED:1 2 3>>>");fgets(buf,sizeof(buf),stdin);printf("输入控制命令:0熄灭 1开灯>>>");fgets(buf+1,sizeof(buf),stdin);buf[strlen(buf)-1]='\0';write(fd,buf,sizeof(buf));}close(fd);return 0;}

//驱动程序
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include "led.h"char kbuf[128]={0};
gpio_t *vir_led1;
gpio_t *vir_led2;
gpio_t *vir_led3;
unsigned int *vir_rcc;
int major; //保存主设备号
//封装操作方法
int mycdev_open(struct inode *inode, struct file *file)
{printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);return 0;
}
ssize_t mycdev_read(struct file *file, char *ubuf, size_t size, loff_t *lof)
{int ret;if(sizeof(kbuf) < size)            //判断用户空间长度是否比内核空间大size=sizeof(kbuf);ret=copy_to_user(ubuf,kbuf,size);  //将内核数据拷贝到用户if(ret){printk("copy_to_user filed\n");return -EIO;}printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);return 0;
}
ssize_t mycdev_write(struct file *file, const char *ubuf, size_t size, loff_t *lof)
{int ret;if(sizeof(kbuf) < size)size=sizeof(kbuf);ret=copy_from_user(kbuf,ubuf,size);if(ret){printk("copy_from_user filed\n");return -EIO;}if(kbuf[0]=='1')      //LED1{if(kbuf[1]=='1')  					//开灯vir_led1->ODR |= (0x1 << 10);else if(kbuf[1]=='0') 				//关灯vir_led1->ODR &= (~(0x1 << 10));}else if(kbuf[0]=='2')      //LED2{if(kbuf[1]=='1')  					//开灯vir_led2->ODR |= (0x1 << 10);else if(kbuf[1]=='0') 				//关灯vir_led2->ODR &= (~(0x1 << 10));}else if(kbuf[0]=='3')      //LED3{if(kbuf[1]=='1')  					//开灯vir_led3->ODR |= (0x1 << 8);else if(kbuf[1]=='0') 				//关灯vir_led3->ODR &= (~(0x1 << 8));}printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);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初始化
struct file_operations fops =
{.open    =  mycdev_open,.read    =  mycdev_read,.write   =  mycdev_write,.release =  mycdev_close,
};int led_init(void)
{//映射物理寄存器vir_led1=ioremap(PHY_LED1_ADDR,sizeof(gpio_t));if(vir_led1 == NULL){printk("vir_led1寄存器地址映射表失败\n");return -EFAULT;}vir_led2=ioremap(PHY_LED2_ADDR,sizeof(gpio_t));if(vir_led2 == NULL){printk("vir_led2寄存器地址映射表失败\n");return -EFAULT;}vir_led3=ioremap(PHY_LED3_ADDR,sizeof(gpio_t));if(vir_led3 == NULL){printk("vir_led1寄存器地址映射表失败\n");return -EFAULT;}vir_rcc=ioremap(PHY_RCC,4);if(vir_rcc==NULL){printk("vir_rcc寄存器地址映射表失败\n");return -EFAULT;}printk("寄存器地址映射成功\n");//寄存器初始化(*vir_rcc) |= (0x3 << 4);//rcc使能vir_led1->MODER &= (~(0X3 << 20));//设置为输出vir_led1->MODER |= (0x1 << 20);vir_led1->ODR &= (~(0x1 << 10));//灭灯vir_led2->MODER &= (~(0X3 << 20));//设置为输出vir_led2->MODER |= (0x1 << 20);vir_led2->ODR &= (~(0x1 << 10));//灭灯vir_led3->MODER &= (~(0X3 << 16));//设置为输出vir_led3->MODER |= (0x1 << 16);vir_led3->ODR &= (~(0x1 << 8));//灭灯printk("硬件寄存器初始化成功\n");return 0;
}
static int __init mycdev_init(void)
{//字符设备驱动注册major = register_chrdev(0,"mychrdev",&fops);if(major < 0){printk("字符设备驱动注册失败\n");return major;}printk("字符设备驱动注册成功major=%d\n",major);//初始化ledled_init();return 0;
}static void __exit mycdev_exit(void)
{//取消寄存器地址映射iounmap(vir_led1);iounmap(vir_led2);iounmap(vir_led3);iounmap(vir_rcc);//字符设备驱动注销unregister_chrdev(major,"mychrdev");printk("字符设备驱动注销\n");
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");

结果