驱动开发，stm32mp157a开发板的led灯控制实验

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
endifPWD:=$(shell pwd) #模块化编译文件路径
all:make -C $(KERNELDIR) M=$(PWD) modules
clean:make -C $(KERNELDIR) M=$(PWD) cleanobj-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;   }//LED1if(kbuf[0] == '1'){//开灯(*vir_odr) |= (0x1 << 10);}else if(kbuf[0] == '0'){//关灯逻辑(*vir_odr) &= (~(0x1 << 10));}//LED2if(kbuf[1] == '1'){//开灯(*vir_odr2) |= (0x1 << 10);}else if(kbuf[1] == '0'){//关灯逻辑(*vir_odr2) &= (~(0x1 << 10));}//LED3if(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;  
}