1.实验目的

        编写LED灯的驱动，在应用程序中编写控制LED灯亮灭的代码逻辑实现LED灯功能的控制；

 

2.LED灯相关寄存器分析

LED1->PE10 LED1亮灭：

RCC寄存器[4]->1 0X50000A28

GPIOE_MODER[21:20]->01 (输出) 0X50006000

GPIOE_ODR[10]->1(输出高电平) 0（输出低电平）0X50006014

LED2->PF10 LED2亮灭：

RCC寄存器[5]->1 0X50000A28

GPIOE_MODER[21:20]->01 (输出) 0X50006000

GPIOE_ODR[10]->1(输出高电平) 0（输出低电平）0X50006014

LED3->PE8 LED3亮灭：

RCC寄存器[4]->1 0X50000A28

GPIOE_MODER[17:16]->01 (输出) 0X50006000

GPIOE_ODR[8]->1(输出高电平) 0（输出低电平）0X50006014

GPIOE_OTYPER默认为00

GPIOE_PUPDR默认为0

GPIOE_OSPEEDR默认为00

3.编写代码

---Makefile---工程管理文件

modname?=demo
arch?=arm
ifeq ($(arch),arm)
KERNELDIR:= /home/ubuntu/FSMP1A/linux-stm32mp-5.10.61-stm32mp-r2-r0/linux-5.10.61 #编译生成ARM架构
else
KERNELDIR:=/lib/modules/$(shell uname -r)/build #编译生成X86架构
endif

PWD:=$(shell pwd) #模块化编译文件路径
all:
	make -C $(KERNELDIR) M=$(PWD) modules
clean:
	make -C $(KERNELDIR) M=$(PWD) clean

obj-m:=$(modname).o

---head.h---头文件

#ifndef __HEAD_H__
#define __HEAD_H__

//LED1和LED3寄存器地址
#define LED1_3_MODER (0xc50006000)
#define LED1_3_ODR (0xc50006014)
#define LED_RCC (0xc50000A28)

//LED2寄存器地址
#define LED2_MODER (0xc50007000)
#define LED2_ODR (0xc50007014)

#endif

---mychrdev.c---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 "head.h"

char kbuf[128] = {0};
unsigned int major;
unsigned int *vir_moder;
unsigned int *vir_odr;
unsigned int *vir_rcc;
unsigned int *vir_moder2;
unsigned int *vir_odr2;

//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;
    ret = copy_to_user(ubuf,kbuf,size);
    if(ret)
    {
        printk("copy_to_user err\n");
        return -EIO;
    }

    return 0;
}
ssize_t mycdev_write(struct file *file, const char *ubuf, size_t size, loff_t *lof)
{
    int ret;
    ret = copy_from_user(kbuf,ubuf,size);
    if(ret)
    {
        printk("copy_from_user err\n"); 
        return -EIO;   
    }
    
    //LED1
    if(kbuf[0] == '1')
    {
        //开灯
        (*vir_odr) |= (0x1 << 10);
    }
    else if(kbuf[0] == '0')
    {
        //关灯逻辑
        (*vir_odr) &= (~(0x1 << 10));
    }

    //LED2
    if(kbuf[1] == '1')
    {
        //开灯
        (*vir_odr2) |= (0x1 << 10);
    }
    else if(kbuf[1] == '0')
    {
        //关灯逻辑
        (*vir_odr2) &= (~(0x1 << 10));
    }

    //LED3
    if(kbuf[2] == '1')
    {
        //开灯
        (*vir_odr) |= (0x1 << 8);
    }
    else if(kbuf[2] == '0')
    {
        //关灯逻辑
        (*vir_odr) &= (~(0x1 << 8));
    }
   
    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,
};

//入口函数
static int __init mycdev_init(void)
{
	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);

    //相关寄存器的内存映射
    vir_odr=ioremap(LED1_3_ODR,4);
    if(vir_odr == NULL)
    {
        printk("物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }

    vir_rcc=ioremap(LED_RCC,4);
    if(vir_rcc == NULL)
    {
        printk("物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }

    vir_moder=ioremap(LED1_3_MODER,4);
    if(vir_moder == NULL)
    {
        printk("物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }

    vir_moder2=ioremap(LED2_MODER,4);
    if(vir_moder2 == NULL)
    {
        printk("物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }

    vir_odr2=ioremap(LED2_ODR,4);
    if(vir_odr2 == NULL)
    {
        printk("物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
    printk("寄存器内存映射成功\n");

    //硬件寄存器的初始化
    (*vir_rcc) |= (0x3 << 4);
    
    //LED1
    (*vir_moder) &= (~(0x3 << 20));
    (*vir_moder) |= (0x1 << 20);

    (*vir_odr) &= (~(0x1 << 10));

    //LED2
    (*vir_moder2) &= (~(0x3 << 20));
    (*vir_moder2) |= (0x1 << 20);

    (*vir_odr2) &= (~(0x1 << 10));

    //LED3
    (*vir_moder) &= (~(0x3 << 16));
    (*vir_moder) |= (0x1 << 16);
    
    (*vir_odr) &= (~(0x1 << 8));
     
	return 0;
}

//出口函数
static void __exit mycdev_exit(void)
{
    //取消物理内存的映射
    iounmap(vir_moder);
    iounmap(vir_odr);
    iounmap(vir_rcc);
     iounmap(vir_moder2);
    iounmap(vir_odr2);
    
    //字符设备驱动注销
    unregister_chrdev(major,"mychrdev");
}

//声明
//入口函数地址
module_init(mycdev_init);
//出口函数地址
module_exit(mycdev_exit);
//遵循的GPL协议
MODULE_LICENSE("GPL");

---test.c---应用程序测试程序

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>

int main(int argc,char const *argv[])
{
    char buf[128]={0};
    int fd = open("/dev/mychrdev",O_RDWR);

    if(fd < 0)
    {
        printf("设备文件打开失败\n");
        exit(-1);
    }
    while(1)
    {
        printf("请输入对LED1的控制命令1(开灯)0(关灯)>>> ");
        fgets(buf,sizeof(buf),stdin);
        buf[strlen(buf)-1] = '\0';
        write(fd,buf,sizeof(buf));

        printf("请输入对LED2的控制命令1(开灯)0(关灯)>>> ");
        fgets(buf+1,sizeof(buf),stdin);
        buf[strlen(buf)-1] = '\0';
        write(fd,buf,sizeof(buf));

        printf("请输入对LED3的控制命令1(开灯)0(关灯)>>> ");
        fgets(buf+2,sizeof(buf),stdin);
        buf[strlen(buf)-1] = '\0';
        write(fd,buf,sizeof(buf));
        memset(buf,0,sizeof(buf));
    }

    close(fd);   
    return 0;  
}

 

4.测试