驱动开发，stm32mp157a开发板的led灯控制实验-Toy模板网

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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__

typedef struct
{
    unsigned int MODER;
    unsigned int OTYPER;
    unsigned int OSPEEDR;
    unsigned int PUPDR;
    unsigned int IDR;
    unsigned int ODR;   
}gpio_t;

//LED1和LED3寄存器地址
#define LED1_ADDR 0x50006000
#define LED2_ADDR 0x50007000
#define LED3_ADDR 0x50006000
#define RCC_ADDR 0x50000A28

#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"
#include<linux/device.h>

char kbuf[128] = {0};
unsigned int major;
gpio_t *vir_led1;
gpio_t *vir_led2;
gpio_t *vir_led3;
unsigned int *vir_rcc;

struct class *cls;
struct device *dev;

//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(size > sizeof(kbuf))
    {
        size = sizeof(kbuf);
    }
    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)
{
    unsigned long ret;
    if(size > sizeof(kbuf))
    {
        size = sizeof(kbuf);
    }
    ret = copy_from_user(kbuf,ubuf,size);
    if(ret)
    {
        printk("copy_from_user err\n"); 
        return -EIO;   
    }
    
    switch(kbuf[0])
    {
        case '1':
            if(kbuf[1] == '1')  //开灯
                vir_led1->ODR |= (0x1 << 10);
            else if(kbuf[1] == '0')  //关灯
                vir_led1->ODR &= (~(0x1 << 10));
            break;
         case '2':
            if(kbuf[1] == '1')  //开灯
                vir_led2->ODR |= (0x1 << 10);
            else if(kbuf[1] == '0') //关灯
                vir_led2->ODR &= (~(0x1 << 10));
            break;
         case '3':
            if(kbuf[1] == '1')  //开灯
                vir_led3->ODR |= (0x1 << 8);
            else if(kbuf[1] == '0') //关灯
                vir_led3->ODR &= (~(0x1 << 8));
            break;
        default:
            printk("输入错误\n"); 
    }
    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,
};

//相关寄存器地址映射及初始化
int all_led_init(void)
{
    //相关寄存器的内存映射
    vir_led1=ioremap(LED1_ADDR,sizeof(gpio_t));
    if(vir_led1 == NULL)
    {
        printk("物理内存映射失败%d\n",__LINE__);
        return -ENOMEM;
    }

    vir_led2=ioremap(LED2_ADDR,sizeof(gpio_t));
    if(vir_led2 == NULL)
    {
        printk("物理内存映射失败%d\n",__LINE__);
        return -ENOMEM;
    }

    vir_led3 = vir_led1;

    vir_rcc=ioremap(RCC_ADDR,4);
    if(vir_rcc == NULL)
    {
        printk("物理内存映射失败%d\n",__LINE__);
        return -ENOMEM;
    }
    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_led1->MODER &= (~(0x3 << 20));
    vir_led1->MODER |= (0x1 << 20);
    vir_led1->ODR &= (~(0x1 << 10));

    //LED2
    vir_led2->MODER &= (~(0x3 << 20));
    vir_led2->MODER |= (0x1 << 20);
    vir_led2->ODR &= (~(0x1 << 10));

    //LED3
    vir_led3->MODER &= (~(0x3 << 16));
    vir_led3->MODER |= (0x1 << 16);
    vir_led3->ODR &= (~(0x1 << 8));

    printk("寄存器初始化成功\n");
    return 0;
}

//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);

    //寄存器映射及初始化
    all_led_init();

    //向上提交目录
    cls = class_create(THIS_MODULE,"mychrdev");
    if(IS_ERR(cls))
    {
        printk("向上提交目录失败\n");
        return -PTR_ERR(cls);
    }
    printk("向上提交目录成功\n");

    //向上提交设备节点信息
    int i;
    for(i=0; i<3; i++)
    {
        dev = device_create(cls,NULL,MKDEV(major,i),NULL,"mychrdev%d",i);
        if(IS_ERR(dev))
        {
            printk("向上提交设备节点信息失败\n");
            return -PTR_ERR(dev);
        }
    }
    printk("向上提交设备节点信息成功\n");

	return 0;
}

//出口函数
static void __exit mycdev_exit(void)
{
    //销毁设备节点信息
    int i;
    for(i=0; i<3; i++)
    {
        device_destroy(cls,MKDEV(major,i));
    }

    //销毁目录信息
    class_destroy(cls);

    //取消物理内存的映射
    iounmap(vir_led1);
    iounmap(vir_led2);
    iounmap(vir_rcc);
    
    //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/mychrdev0",O_RDWR);

    if(fd < 0)
    {
        printf("设备文件打开失败\n");
        exit(-1);
    }
    while(1)
    {
        printf("第一个字符：1(LED1) 2(LED2) 3(LED3)\n");
        printf("第二个字符1(开灯)0(关灯)\n");
        printf("输入控制灯的两个字符>>> ");
       
        fgets(buf,sizeof(buf),stdin);
        buf[strlen(buf)-1] = '\0';
        //像设备文件中写
        write(fd,buf,sizeof(buf));
    }

    close(fd);
    
    return 0;  
}