linux tty驱动源码分析

int index;

/* Protects ldisc changes: Lock tty not pty */

struct mutex ldisc_mutex;

struct tty_ldisc *ldisc; /*TTY 线路规程与 TTY 核心层主要连接接

口

struct pid *pgrp; /* Protected by ctrl lock */

struct pid *session;

unsigned long flags;

int count;

struct winsize winsize; /* termios mutex */

unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;

unsigned char low_latency:1, warned:1;

unsigned char ctrl_status; /* ctrl_lock */

unsigned int receive_room; /* Bytes free for queue */

struct tty_bufhead buf; /* Locked internally */

int alt_speed; /* For magic substitution of 38400 bps */

wait_queue_head_t write_wait;

wait_queue_head_t read_wait;

struct work_struct hangup_work;

void *disc_data;

void *driver_data;

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