linux下字符設(shè)備有哪些

struct tty_struct { struct termios termios; int pgrp; int stopped; void (*write)(struct tty_struct * tty); struct tty_queue read_q;               //讀隊列 struct tty_queue write_q;              //寫隊列 struct tty_queue secondary;            //tty輔助隊列(存放規(guī)格化后的字符) };

//include/linux/cdev.h struct cdev {         struct kobject kobj;         struct module *owner;         const struct file_operations *ops;         struct list_head list;         dev_t dev;         unsigned int count; };

//include/linux/fs.h struct file_operations {         struct module *owner;         loff_t (*llseek) (struct file *, loff_t, int);         ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);         ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);         ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);         ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);         int (*iterate) (struct file *, struct dir_context *);         unsigned int (*poll) (struct file *, struct poll_table_struct *);         long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);         long (*compat_ioctl) (struct file *, unsigned int, unsigned long);         int (*mmap) (struct file *, struct vm_area_struct *);         int (*mremap)(struct file *, struct vm_area_struct *);         int (*open) (struct inode *, struct file *);         int (*flush) (struct file *, fl_owner_t id);         int (*release) (struct inode *, struct file *);         int (*fsync) (struct file *, loff_t, loff_t, int datasync);         int (*aio_fsync) (struct kiocb *, int datasync);         int (*fasync) (int, struct file *, int);         int (*lock) (struct file *, int, struct file_lock *);         ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);         unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);         int (*check_flags)(int);         int (*flock) (struct file *, int, struct file_lock *);         ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);         ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);         int (*setlease)(struct file *, long, struct file_lock **, void **);         long (*fallocate)(struct file *file, int mode, loff_t offset,                           loff_t len);         void (*show_fdinfo)(struct seq_file *m, struct file *f); #ifndef CONFIG_MMU         unsigned (*mmap_capabilities)(struct file *); #endif };

extern struct class * __must_check __class_create(struct module *owner,                                                   const char *name,                                                   struct lock_class_key *key);  #define class_create(owner, name)                ({                                                       static struct lock_class_key __key;              __class_create(owner, name, &__key);     })

struct class {         const char              *name;         struct module           *owner;          struct class_attribute          *class_attrs;         const struct attribute_group    **dev_groups;         struct kobject                  *dev_kobj;          int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);         char *(*devnode)(struct device *dev, umode_t *mode);          void (*class_release)(struct class *class);         void (*dev_release)(struct device *dev);          int (*suspend)(struct device *dev, pm_message_t state);         int (*resume)(struct device *dev);          const struct kobj_ns_type_operations *ns_type;         const void *(*namespace)(struct device *dev);          const struct dev_pm_ops *pm;          struct subsys_private *p; };

static inline long __must_check PTR_ERR(const void *ptr) { 	return (long) ptr; }  static inline long __must_check IS_ERR(const void *ptr) { 	return IS_ERR_VALUE((unsigned long)ptr); }

#include <linux/fs.h>		 //file_operations聲明 #include <linux/module.h>    //module_init  module_exit聲明 #include <linux/init.h>      //__init  __exit 宏定義聲明 #include <linux/device.h>	 //class  devise聲明 #include <linux/uaccess.h>   //copy_from_user 的頭文件 #include <linux/types.h>     //設(shè)備號  dev_t 類型聲明 #include <asm/io.h>          //ioremap iounmap的頭文件  #define DEVICE_CNT 0	//設(shè)備號個數(shù)  struct led_device{ 	dev_t devid;	//設(shè)備號 	int major;	//主設(shè)備號 	int minor;	//次設(shè)備號 	char* name = "led";	//驅(qū)動名 	struct cdev led_dev;	//cdev 結(jié)構(gòu)體 	struct class *class;	/* 類 	*/ 	struct device* device;	//設(shè)備 };  struct led_device led;   static int led_open(struct inode *inode, struct file *filp) { 	return 0; }  static ssize_t led_write(struct file *filp, const char __user *buf, size_t cnt, loff_t *offt) { 	return 0; }   static ssize_t led_read(struct file *filp, char __user *buf, size_t cnt, loff_t *offt) { 	return 0; }    /* 設(shè)備操作函數(shù) */ static struct file_operations led_fo = { 	.owner = THIS_MODULE, 	.open = led_open, 	.read = led_read, 	.write = led_write, };  static int _init led_init() { 	/*注冊字符設(shè)備驅(qū)動*/ 	 	/*1.注冊設(shè)備號*/ 	led.major = 0;	//由內(nèi)核自動分配主設(shè)備號 	if(led.major)	//如果分配了的話就注冊 	{ 		led.devid = MKDEV(led.major,0);	 		register_chrdev_region(led.devid,DEVICE_CNT,led.name);	//將驅(qū)動注冊到內(nèi)核中 	} 	else{		//如果沒有分配的話 					//從0號（次設(shè)備號）開始申請 		alloc_chrdev_region(&led.devid,0,DEVICE_CNT,led.name);		//申請設(shè)備號 		led.major = MAJOR(led.devid);	//獲取主設(shè)備號 		led.minor = MANOR(led.devid);	//獲取次設(shè)備號 	} 	printk("newcheled major=%d,minor=%drn",newchrled.major, newchrled.minor);	  	/*2.初始化 cdev 結(jié)構(gòu)體*/ 	led.led_dev.woner = THIS_MODULE; 	cdev_init(&led.led_dev,&led_fo);	//將操作函數(shù)初始化到cdev結(jié)構(gòu)體  	/*3.應該是向鏈表中添cdev*/ 	cdev_add(&led.led_dev,led.devid,DEVICE_CNT);	  	/*4.創(chuàng)建節(jié)點*/ 	led.class = class_create(THIS_MODULE,led.name);		//先創(chuàng)建一個類 	led.device = device_create(led.class,NULL,led.devid,NULL);	//創(chuàng)建設(shè)備  	return 0; 		 }  static void _exit led_exit() { 	/* 注銷字符設(shè)備驅(qū)動 */ 	cdev_del(&newchrled.cdev);/*  刪除cdev */ 	unregister_chrdev_region(newchrled.devid, NEWCHRLED_CNT); /* 注銷設(shè)備號 */  	device_destroy(newchrled.class, newchrled.devid); 	class_destroy(newchrled.class); }    /*注冊字符設(shè)備入口與卸載入口*/ module_init(led_init); module_exit(led_exit); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("zhoujianghong");