驱动开发（10/10-林雪阵）

news/2024/4/29 15:48:19/文章来源:https://blog.csdn.net/weixin_47348012/article/details/127250451

终端输入1--->LED1点亮

终端输入2--->LED2点亮

终端输入3--->LED3点亮

终端输入0--->LED熄灭

chdev.c (底层驱动代码）

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
//#include "myled.h"
#include <linux/io.h>
#define CNAME "mycdev"#define PHY_LED1_MODER 0X50006000
#define PHY_LED1_ODR 0X50006014
#define PHY_LED1_RCC 0x50000A28#define PHY_LED2_MODER 0X50007000
#define PHY_LED2_ODR 0X50007014
#define PHY_LED2_RCC 0x50000A28#define PHY_LED3_MODER 0X50006000
#define PHY_LED3_ODR 0X50006014
#define PHY_LED3_RCC 0x50000A28int major;
char kbuf[128]={};  //定义数组用于存放和用户之间拷贝的数据
unsigned int *vir_moder1;
unsigned int *vir_moder2;
unsigned int *vir_odr1;
unsigned int *vir_odr2;
unsigned int *vir_rcc;ssize_t mycdev_read (struct file *file, char __user *ubuf, size_t size, loff_t *loff)
{//size是用户期待读到的字节长度int ret;if(size>sizeof(kbuf))size=sizeof(kbuf);ret=copy_to_user(ubuf,kbuf,size);if(ret){printk("数据从内核向用户拷贝失败\n");return -EIO;}return size;
}
ssize_t mycdev_write (struct file *file, const char __user *ubuf, size_t size, loff_t *loff)
{int ret;if(size > sizeof(kbuf))size=sizeof(kbuf);ret=copy_from_user(kbuf,ubuf,size);if(ret){printk("数据从用户向内核拷贝失败\n");return -EIO;}if(kbuf[0] == '1'){(*vir_odr1) |= (1<<10);}else if(kbuf[0]== '2'){(*vir_odr2) |= (1<<10);}else if(kbuf[0] == '3'){(*vir_odr1) |= (1<<8);}else{(*vir_odr1) &= ~(1<<10);(*vir_odr2) &= ~(1<<10);(*vir_odr1) &= ~(1<<8);}return size;
}
int mycdev_open (struct inode *inode, struct file *file)
{printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);return 0;
}
int mycdev_release (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_release
};
static int __init demo_init(void)
{major=register_chrdev(0,CNAME,&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);//moder 地址映射//GPIOEvir_moder1=ioremap(PHY_LED1_MODER,4);if(vir_moder1 ==NULL){printk("vir_moder1 映射失败\n");return -ENOMEM;}printk("vir_moder1 映射成功\n");//GPIOFvir_moder2=ioremap(PHY_LED2_MODER,4);if(vir_moder2 ==NULL){printk("vir_moder2 映射失败\n");return -ENOMEM;}printk("vir_moder2 映射成功\n");//odr 地址映射//GPIOEvir_odr1=ioremap(PHY_LED1_ODR,4);if(vir_odr1 ==NULL){printk("vir_odr1 映射失败\n");return -ENOMEM;}printk("vir_odr1 映射成功\n");//GPIOFvir_odr2=ioremap(PHY_LED2_ODR,4);if(vir_odr2 ==NULL){printk("vir_odr2 映射失败\n");return -ENOMEM;}printk("vir_odr2 映射成功\n");//rcc 地址映射vir_rcc=ioremap(PHY_LED1_RCC,4);if(vir_rcc ==NULL){printk("vir_rcc 映射失败\n");return -ENOMEM;}printk("vir_rcc 映射成功\n");//LED1 init(*vir_moder1) &= (~(3<<20));(*vir_moder1) |= (1<<20);(*vir_odr1) &= (~(1<<10));(*vir_rcc) |= (1<<4);//LED2 init(*vir_moder2) &= (~(3<<20));(*vir_moder2) |= (1<<20);(*vir_odr2) &= (~(1<<10));(*vir_rcc) |= (1<<5);//LED3 init(*vir_moder1) &= (~(3<<16));(*vir_moder1) |= (1<<16);(*vir_odr1) &= (~(1<<8));return 0;
}
static void __exit demo_exit(void)
{unregister_chrdev(major,CNAME);printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);}
//module_init和module_exit是内核提供的宏
//告诉内核驱动的出口函数和出口函数的地址
module_init(demo_init);
module_exit(demo_exit);
//声明遵循GPL开源协议
MODULE_LICENSE("GPL");

test.c(应用层测试代码）

#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]={};int fd=open("/dev/mycdev",O_RDWR);if(fd<0){printf("打开设备文件失败");exit(-1);}printf("设备文件打开成功\n");//在终端输入printf("请输入控制命令 1,2,3开灯 0关灯\n");fgets(buf,sizeof(buf),stdin);buf[strlen(buf)-1]='\0';write(fd,buf,sizeof(buf));memset(buf,0,sizeof(buf));read(fd,buf,sizeof(buf));printf("读取到的数据为：%s\n",buf);close(fd);return 0;   
}

makefile(编译文件）

modname ?= chdev
arch ?= arm
ifeq ($(arch),arm)#arm架构
KERNELDIR := /home/ubuntu/fsmp1a/linux-stm32mp-5.10.61-stm32mp-r2-r0/linux-5.10.61
else
KERNELDIR := /lib/modules/$(shell uname -r)/build
endif
PWD:=$(shell pwd)
KBUILD_EXTRA_SYMBOLS+=/home/ubuntu/08_驱动/day1/1/Module.symvers
all:make -C $(KERNELDIR) M=$(PWD) modules
# make -C $(KERNELDIR)
#进入内核顶层目录下，读取对应的Makefile文件，然后执行make
#M=$(PWD) :指定编译模块的路径为当前驱动路径
#make modules :模块化编译
#进入
clean:make -C $(KERNELDIR) M=$(PWD) cleanobj-m:=$(modname).o