linux下有哪些字符设备

structtty_struct{
structtermiostermios;
intpgrp;
intstopped;
void(*write)(structtty_struct*tty);
structtty_queueread_q;//读队列
structtty_queuewrite_q;//写队列
structtty_queuesecondary;//tty辅助队列(存放规格化后的字符)
};

//include/linux/cdev.h
structcdev{
structkobjectkobj;
structmodule*owner;
conststructfile_operations*ops;
structlist_headlist;
dev_tdev;
unsignedintcount;
};

//include/linux/fs.h
structfile_operations{
structmodule*owner;
loff_t(*llseek)(structfile*,loff_t,int);
ssize_t(*read)(structfile*,char__user*,size_t,loff_t*);
ssize_t(*write)(structfile*,constchar__user*,size_t,loff_t*);
ssize_t(*read_iter)(structkiocb*,structiov_iter*);
ssize_t(*write_iter)(structkiocb*,structiov_iter*);
int(*iterate)(structfile*,structdir_context*);
unsignedint(*poll)(structfile*,structpoll_table_struct*);
long(*unlocked_ioctl)(structfile*,unsignedint,unsignedlong);
long(*compat_ioctl)(structfile*,unsignedint,unsignedlong);
int(*mmap)(structfile*,structvm_area_struct*);
int(*mremap)(structfile*,structvm_area_struct*);
int(*open)(structinode*,structfile*);
int(*flush)(structfile*,fl_owner_tid);
int(*release)(structinode*,structfile*);
int(*fsync)(structfile*,loff_t,loff_t,intdatasync);
int(*aio_fsync)(structkiocb*,intdatasync);
int(*fasync)(int,structfile*,int);
int(*lock)(structfile*,int,structfile_lock*);
ssize_t(*sendpage)(structfile*,structpage*,int,size_t,loff_t*,int);
unsignedlong(*get_unmapped_area)(structfile*,unsignedlong,unsignedlong,unsignedlong,unsignedlong);
int(*check_flags)(int);
int(*flock)(structfile*,int,structfile_lock*);
ssize_t(*splice_write)(structpipe_inode_info*,structfile*,loff_t*,size_t,unsignedint);
ssize_t(*splice_read)(structfile*,loff_t*,structpipe_inode_info*,size_t,unsignedint);
int(*setlease)(structfile*,long,structfile_lock**,void**);
long(*fallocate)(structfile*file,intmode,loff_toffset,
loff_tlen);
void(*show_fdinfo)(structseq_file*m,structfile*f);
#ifndefCONFIG_MMU
unsigned(*mmap_capabilities)(structfile*);
#endif
};

externstructclass*__must_check__class_create(structmodule*owner,
constchar*name,
structlock_class_key*key);

#defineclass_create(owner,name)
({
staticstructlock_class_key__key;
__class_create(owner,name,&__key);
})

structclass{
constchar*name;
structmodule*owner;

structclass_attribute*class_attrs;
conststructattribute_group**dev_groups;
structkobject*dev_kobj;

int(*dev_uevent)(structdevice*dev,structkobj_uevent_env*env);
char*(*devnode)(structdevice*dev,umode_t*mode);

void(*class_release)(structclass*class);
void(*dev_release)(structdevice*dev);

int(*suspend)(structdevice*dev,pm_message_tstate);
int(*resume)(structdevice*dev);

conststructkobj_ns_type_operations*ns_type;
constvoid*(*namespace)(structdevice*dev);

conststructdev_pm_ops*pm;

structsubsys_private*p;
};

staticinlinelong__must_checkPTR_ERR(constvoid*ptr)
{
	return(long)ptr;
}

staticinlinelong__must_checkIS_ERR(constvoid*ptr)
{
	returnIS_ERR_VALUE((unsignedlong)ptr);
}

#include		//file_operations声明
#include//module_initmodule_exit声明
#include//__init__exit宏定义声明
#include	//classdevise声明
#include//copy_from_user的头文件
#include//设备号dev_t类型声明
#include//ioremapiounmap的头文件

#defineDEVICE_CNT0	//设备号个数

structled_device{
	dev_tdevid;	//设备号
	intmajor;	//主设备号
	intminor;	//次设备号
	char*name="led";	//驱动名
	structcdevled_dev;	//cdev结构体
	structclass*class;	/*类	*/
	structdevice*device;	//设备
};

structled_deviceled;


staticintled_open(structinode*inode,structfile*filp)
{
	return0;
}

staticssize_tled_write(structfile*filp,constchar__user*buf,size_tcnt,loff_t*offt)
{
	return0;
}


staticssize_tled_read(structfile*filp,char__user*buf,size_tcnt,loff_t*offt)
{
	return0;
}



/*设备操作函数*/
staticstructfile_operationsled_fo={
	.owner=THIS_MODULE,
	.open=led_open,
	.read=led_read,
	.write=led_write,
};

staticint_initled_init()
{
	/*注册字符设备驱动*/
	
	/*1.注册设备号*/
	led.major=0;	//由内核自动分配主设备号
	if(led.major)	//如果分配了的话就注册
	{
		led.devid=MKDEV(led.major,0);	
		register_chrdev_region(led.devid,DEVICE_CNT,led.name);	//将驱动注册到内核中
	}
	else{		//如果没有分配的话
					//从0号（次设备号）开始申请
		alloc_chrdev_region(&led.devid,0,DEVICE_CNT,led.name);		//申请设备号
		led.major=MAJOR(led.devid);	//获取主设备号
		led.minor=MANOR(led.devid);	//获取次设备号
	}
	printk("newcheledmajor=%d,minor=%drn",newchrled.major,newchrled.minor);	

	/*2.初始化cdev结构体*/
	led.led_dev.woner=THIS_MODULE;
	cdev_init(&led.led_dev,&led_fo);	//将操作函数初始化到cdev结构体

	/*3.应该是向链表中添cdev*/
	cdev_add(&led.led_dev,led.devid,DEVICE_CNT);	

	/*4.创建节点*/
	led.class=class_create(THIS_MODULE,led.name);		//先创建一个类
	led.device=device_create(led.class,NULL,led.devid,NULL);	//创建设备

	return0;
		
}

staticvoid_exitled_exit()
{
	/*注销字符设备驱动*/
	cdev_del(&newchrled.cdev);/*删除cdev*/
	unregister_chrdev_region(newchrled.devid,NEWCHRLED_CNT);/*注销设备号*/

	device_destroy(newchrled.class,newchrled.devid);
	class_destroy(newchrled.class);
}



/*注册字符设备入口与卸载入口*/
module_init(led_init);
module_exit(led_exit);
MODULE_LICENSE("GPLv2");
MODULE_AUTHOR("zhoujianghong");