GLOBDEV——linux字符设备驱动程序

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#include"linux/module.h"#include"linux/types.h"#include"linux/fs.h"#include"linux/errno.h"#include"linux/mm.h"#include"linux/sched.h"#include"linux/init.h"#include"linux/cdev.h"#include"asm/io.h"#include"asm/system.h"#include"asm/uaccess.h"#define GLOB_SIZE 0x1000  //4KB#define MEM_CLEAR 0x01//clear//////function externstatic ssize_t glob_read(struct file *filep,char __user *buf,size_t count,loff_t *ppos);static ssize_t glob_write(struct file *filp,const char __user *buf,size_t count,loff_t *ppos);static void glob_setup_cdev();static int glob_init(void);static void glob_exit();///struct struct glob_dev{struct cdev cdev;unsigned char mem[GLOB_SIZE];};struct file_operations glob_file_operations={.owner=THIS_MODULE,.read=glob_read,.write=glob_write,};static struct glob_dev dev;static int glob_major;static dev_t devnumber;static int glob_init(void){int result=alloc_chrdev_region(&devnumber,0,1,"GLOBDEV");if(result<0){printk("<0>alloc_chrdev_region is return number is %d!\n",result);return result;}glob_major=MAJOR(devnumber);glob_setup_cdev();return 0;}static void glob_exit(){cdev_del(&dev.cdev);unregister_chrdev_region(devnumber,1);}static void glob_setup_cdev(){int err;cdev_init(&(dev.cdev),&glob_file_operations); //cdev与file_operations建立关系dev.cdev.owner=THIS_MODULE;//err=cdev_add(&dev.cdev,devnumber,1);  //添加cdev设备if(err)printk("<0> cdev_add is ERROR!\n");}static ssize_t glob_read(struct file *filep,char __user *buf,size_t count,loff_t *ppos){loff_t p=*ppos;unsigned long int ret;///////处理越界问题。if(p>=GLOB_SIZE)return 0;if(count>GLOB_SIZE-p)count=GLOB_SIZE-p;if((ret=copy_to_user(buf,(void *)(dev.mem+p),count))){printk("<0>success is %ld,faild is %ld!\n",count-ret,ret);}else{printk("<0>success is %ld,faild is %ld!\n",count-ret,ret);*ppos+=count;ret=count;}return (ssize_t)ret;}static ssize_t glob_write(struct file *filp,const char __user *buf,size_t count,loff_t *ppos){loff_t p=*ppos;unsigned long int ret;///////处理越界问题。if(p>GLOB_SIZE)return 0;if(count>GLOB_SIZE-p)count=GLOB_SIZE-p;if((ret=copy_from_user((void *)(dev.mem+p),buf,count))){printk("<0>success is %ld,faild is %ld!\n",count-ret,ret);}else {printk("<0>success is %ld,faild is %ld!\n",count-ret,ret);*ppos+=count;ret=count;}return (ssize_t)ret;}module_init(glob_init);module_exit(glob_exit);MODULE_LICENSE("Dual BSD/GPL");MODULE_AUTHOR("snikeguo@foxmail.com");MODULE_DESCRIPTION("a linux device drivers");MODULE_VERSION("1.0");

学习编写linux驱动程序的时候，我遇到的错误如下：

1.本来是loff_t 错写为lofft ,

2.填充file_operations的时候，应该是.owner .read .write 的后面是逗号，我写成了分号。

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