include/linux/tty.h

#ifndef _LINUX_TTY_H
#define _LINUX_TTY_H

/*
 * 'tty.h' defines some structures used by tty_io.c and some defines.
 */

/*
 * These constants are also useful for user-level apps (e.g., VC
 * resizing).
 */
#define MIN_NR_CONSOLES 1       /* must be at least 1 */
#define MAX_NR_CONSOLES	63	/* serial lines start at 64 */
#define MAX_NR_USER_CONSOLES 63	/* must be root to allocate above this */
		/* Note: the ioctl VT_GETSTATE does not work for
		   consoles 16 and higher (since it returns a short) */

#ifdef __KERNEL__
#include <linux/fs.h>
#include <linux/major.h>
#include <linux/termios.h>
#include <linux/workqueue.h>
#include <linux/tty_driver.h>
#include <linux/tty_ldisc.h>
#include <linux/screen_info.h>
#include <linux/mutex.h>

#include <asm/system.h>


/*
 * (Note: the *_driver.minor_start values 1, 64, 128, 192 are
 * hardcoded at present.)
 */
#define NR_PTYS	CONFIG_LEGACY_PTY_COUNT   /* Number of legacy ptys */
#define NR_UNIX98_PTY_DEFAULT	4096      /* Default maximum for Unix98 ptys */
#define NR_UNIX98_PTY_MAX	(1 << MINORBITS) /* Absolute limit */
#define NR_LDISCS		16

/*
 * This character is the same as _POSIX_VDISABLE: it cannot be used as
 * a c_cc[] character, but indicates that a particular special character
 * isn't in use (eg VINTR has no character etc)
 */
#define __DISABLED_CHAR '\0'

/*
 * This is the flip buffer used for the tty driver.  The buffer is
 * located in the tty structure, and is used as a high speed interface
 * between the tty driver and the tty line discipline.
 */
#define TTY_FLIPBUF_SIZE 512

struct tty_buffer {
	struct tty_buffer *next;
	char *char_buf_ptr;
	unsigned char *flag_buf_ptr;
	int used;
	int size;
	int commit;
	int read;
	/* Data points here */
	unsigned long data[0];
};

struct tty_bufhead {
	struct work_struct		work;
	struct semaphore pty_sem;
	spinlock_t lock;
	struct tty_buffer *head;	/* Queue head */
	struct tty_buffer *tail;	/* Active buffer */
	struct tty_buffer *free;	/* Free queue head */
};
/*
 * The pty uses char_buf and flag_buf as a contiguous buffer
 */
#define PTY_BUF_SIZE	4*TTY_FLIPBUF_SIZE

/*
 * When a break, frame error, or parity error happens, these codes are
 * stuffed into the flags buffer.
 */
#define TTY_NORMAL	0
#define TTY_BREAK	1
#define TTY_FRAME	2
#define TTY_PARITY	3
#define TTY_OVERRUN	4

#define INTR_CHAR(tty) ((tty)->termios->c_cc[VINTR])
#define QUIT_CHAR(tty) ((tty)->termios->c_cc[VQUIT])
#define ERASE_CHAR(tty) ((tty)->termios->c_cc[VERASE])
#define KILL_CHAR(tty) ((tty)->termios->c_cc[VKILL])
#define EOF_CHAR(tty) ((tty)->termios->c_cc[VEOF])
#define TIME_CHAR(tty) ((tty)->termios->c_cc[VTIME])
#define MIN_CHAR(tty) ((tty)->termios->c_cc[VMIN])
#define SWTC_CHAR(tty) ((tty)->termios->c_cc[VSWTC])
#define START_CHAR(tty) ((tty)->termios->c_cc[VSTART])
#define STOP_CHAR(tty) ((tty)->termios->c_cc[VSTOP])
#define SUSP_CHAR(tty) ((tty)->termios->c_cc[VSUSP])
#define EOL_CHAR(tty) ((tty)->termios->c_cc[VEOL])
#define REPRINT_CHAR(tty) ((tty)->termios->c_cc[VREPRINT])
#define DISCARD_CHAR(tty) ((tty)->termios->c_cc[VDISCARD])
#define WERASE_CHAR(tty) ((tty)->termios->c_cc[VWERASE])
#define LNEXT_CHAR(tty)	((tty)->termios->c_cc[VLNEXT])
#define EOL2_CHAR(tty) ((tty)->termios->c_cc[VEOL2])

#define _I_FLAG(tty,f)	((tty)->termios->c_iflag & (f))
#define _O_FLAG(tty,f)	((tty)->termios->c_oflag & (f))
#define _C_FLAG(tty,f)	((tty)->termios->c_cflag & (f))
#define _L_FLAG(tty,f)	((tty)->termios->c_lflag & (f))

#define I_IGNBRK(tty)	_I_FLAG((tty),IGNBRK)
#define I_BRKINT(tty)	_I_FLAG((tty),BRKINT)
#define I_IGNPAR(tty)	_I_FLAG((tty),IGNPAR)
#define I_PARMRK(tty)	_I_FLAG((tty),PARMRK)
#define I_INPCK(tty)	_I_FLAG((tty),INPCK)
#define I_ISTRIP(tty)	_I_FLAG((tty),ISTRIP)
#define I_INLCR(tty)	_I_FLAG((tty),INLCR)
#define I_IGNCR(tty)	_I_FLAG((tty),IGNCR)
#define I_ICRNL(tty)	_I_FLAG((tty),ICRNL)
#define I_IUCLC(tty)	_I_FLAG((tty),IUCLC)
#define I_IXON(tty)	_I_FLAG((tty),IXON)
#define I_IXANY(tty)	_I_FLAG((tty),IXANY)
#define I_IXOFF(tty)	_I_FLAG((tty),IXOFF)
#define I_IMAXBEL(tty)	_I_FLAG((tty),IMAXBEL)
#define I_IUTF8(tty)	_I_FLAG((tty),IUTF8)

#define O_OPOST(tty)	_O_FLAG((tty),OPOST)
#define O_OLCUC(tty)	_O_FLAG((tty),OLCUC)
#define O_ONLCR(tty)	_O_FLAG((tty),ONLCR)
#define O_OCRNL(tty)	_O_FLAG((tty),OCRNL)
#define O_ONOCR(tty)	_O_FLAG((tty),ONOCR)
#define O_ONLRET(tty)	_O_FLAG((tty),ONLRET)
#define O_OFILL(tty)	_O_FLAG((tty),OFILL)
#define O_OFDEL(tty)	_O_FLAG((tty),OFDEL)
#define O_NLDLY(tty)	_O_FLAG((tty),NLDLY)
#define O_CRDLY(tty)	_O_FLAG((tty),CRDLY)
#define O_TABDLY(tty)	_O_FLAG((tty),TABDLY)
#define O_BSDLY(tty)	_O_FLAG((tty),BSDLY)
#define O_VTDLY(tty)	_O_FLAG((tty),VTDLY)
#define O_FFDLY(tty)	_O_FLAG((tty),FFDLY)

#define C_BAUD(tty)	_C_FLAG((tty),CBAUD)
#define C_CSIZE(tty)	_C_FLAG((tty),CSIZE)
#define C_CSTOPB(tty)	_C_FLAG((tty),CSTOPB)
#define C_CREAD(tty)	_C_FLAG((tty),CREAD)
#define C_PARENB(tty)	_C_FLAG((tty),PARENB)
#define C_PARODD(tty)	_C_FLAG((tty),PARODD)
#define C_HUPCL(tty)	_C_FLAG((tty),HUPCL)
#define C_CLOCAL(tty)	_C_FLAG((tty),CLOCAL)
#define C_CIBAUD(tty)	_C_FLAG((tty),CIBAUD)
#define C_CRTSCTS(tty)	_C_FLAG((tty),CRTSCTS)

#define L_ISIG(tty)	_L_FLAG((tty),ISIG)
#define L_ICANON(tty)	_L_FLAG((tty),ICANON)
#define L_XCASE(tty)	_L_FLAG((tty),XCASE)
#define L_ECHO(tty)	_L_FLAG((tty),ECHO)
#define L_ECHOE(tty)	_L_FLAG((tty),ECHOE)
#define L_ECHOK(tty)	_L_FLAG((tty),ECHOK)
#define L_ECHONL(tty)	_L_FLAG((tty),ECHONL)
#define L_NOFLSH(tty)	_L_FLAG((tty),NOFLSH)
#define L_TOSTOP(tty)	_L_FLAG((tty),TOSTOP)
#define L_ECHOCTL(tty)	_L_FLAG((tty),ECHOCTL)
#define L_ECHOPRT(tty)	_L_FLAG((tty),ECHOPRT)
#define L_ECHOKE(tty)	_L_FLAG((tty),ECHOKE)
#define L_FLUSHO(tty)	_L_FLAG((tty),FLUSHO)
#define L_PENDIN(tty)	_L_FLAG((tty),PENDIN)
#define L_IEXTEN(tty)	_L_FLAG((tty),IEXTEN)

struct device;
/*
 * Where all of the state associated with a tty is kept while the tty
 * is open.  Since the termios state should be kept even if the tty
 * has been closed --- for things like the baud rate, etc --- it is
 * not stored here, but rather a pointer to the real state is stored
 * here.  Possible the winsize structure should have the same
 * treatment, but (1) the default 80x24 is usually right and (2) it's
 * most often used by a windowing system, which will set the correct
 * size each time the window is created or resized anyway.
 * 						- TYT, 9/14/92
 */
struct tty_struct {
	int	magic;
	struct tty_driver *driver;
	int index;
	struct tty_ldisc ldisc;
	struct semaphore termios_sem;
	struct termios *termios, *termios_locked;
	char name[64];
	int pgrp;
	int session;
	unsigned long flags;
	int count;
	struct winsize winsize;
	unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
	unsigned char low_latency:1, warned:1;
	unsigned char ctrl_status;
	unsigned int receive_room;	/* Bytes free for queue */

	struct tty_struct *link;
	struct fasync_struct *fasync;
	struct tty_bufhead buf;
	int max_flip_cnt;
	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;
	struct list_head tty_files;

#define N_TTY_BUF_SIZE 4096
	
	/*
	 * The following is data for the N_TTY line discipline.  For
	 * historical reasons, this is included in the tty structure.
	 */
	unsigned int column;
	unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1;
	unsigned char closing:1;
	unsigned short minimum_to_wake;
	unsigned long overrun_time;
	int num_overrun;
	unsigned long process_char_map[256/(8*sizeof(unsigned long))];
	char *read_buf;
	int read_head;
	int read_tail;
	int read_cnt;
	unsigned long read_flags[N_TTY_BUF_SIZE/(8*sizeof(unsigned long))];
	int canon_data;
	unsigned long canon_head;
	unsigned int canon_column;
	struct mutex atomic_read_lock;
	struct mutex atomic_write_lock;
	unsigned char *write_buf;
	int write_cnt;
	spinlock_t read_lock;
	/* If the tty has a pending do_SAK, queue it here - akpm */
	struct work_struct SAK_work;
};

/* tty magic number */
#define TTY_MAGIC		0x5401

/*
 * These bits are used in the flags field of the tty structure.
 * 
 * So that interrupts won't be able to mess up the queues,
 * copy_to_cooked must be atomic with respect to itself, as must
 * tty->write.  Thus, you must use the inline functions set_bit() and
 * clear_bit() to make things atomic.
 */
#define TTY_THROTTLED 		0	/* Call unthrottle() at threshold min */
#define TTY_IO_ERROR 		1	/* Canse an I/O error (may be no ldisc too) */
#define TTY_OTHER_CLOSED 	2	/* Other side (if any) has closed */
#define TTY_EXCLUSIVE 		3	/* Exclusive open mode */
#define TTY_DEBUG 		4	/* Debugging */
#define TTY_DO_WRITE_WAKEUP 	5	/* Call write_wakeup after queuing new */
#define TTY_PUSH 		6	/* n_tty private */
#define TTY_CLOSING 		7	/* ->close() in progress */
#define TTY_LDISC 		9	/* Line discipline attached */
#define TTY_HW_COOK_OUT 	14	/* Hardware can do output cooking */
#define TTY_HW_COOK_IN 		15	/* Hardware can do input cooking */
#define TTY_PTY_LOCK 		16	/* pty private */
#define TTY_NO_WRITE_SPLIT 	17	/* Preserve write boundaries to driver */
#define TTY_HUPPED 		18	/* Post driver->hangup() */

#define TTY_WRITE_FLUSH(tty) tty_write_flush((tty))

extern void tty_write_flush(struct tty_struct *);

extern struct termios tty_std_termios;
extern int fg_console, last_console, want_console;

extern int kmsg_redirect;

extern void console_init(void);
extern int vcs_init(void);

extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
			      const char *routine);
extern char *tty_name(struct tty_struct *tty, char *buf);
extern void tty_wait_until_sent(struct tty_struct * tty, long timeout);
extern int tty_check_change(struct tty_struct * tty);
extern void stop_tty(struct tty_struct * tty);
extern void start_tty(struct tty_struct * tty);
extern int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc);
extern int tty_unregister_ldisc(int disc);
extern int tty_register_driver(struct tty_driver *driver);
extern int tty_unregister_driver(struct tty_driver *driver);
extern struct class_device *tty_register_device(struct tty_driver *driver,
						unsigned index,
						struct device *dev);
extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
			     int buflen);
extern void tty_write_message(struct tty_struct *tty, char *msg);

extern int is_orphaned_pgrp(int pgrp);
extern int is_ignored(int sig);
extern int tty_signal(int sig, struct tty_struct *tty);
extern void tty_hangup(struct tty_struct * tty);
extern void tty_vhangup(struct tty_struct * tty);
extern void tty_unhangup(struct file *filp);
extern int tty_hung_up_p(struct file * filp);
extern void do_SAK(struct tty_struct *tty);
extern void disassociate_ctty(int priv);
extern void tty_flip_buffer_push(struct tty_struct *tty);
extern int tty_get_baud_rate(struct tty_struct *tty);
extern int tty_termios_baud_rate(struct termios *termios);

extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
extern void tty_ldisc_deref(struct tty_ldisc *);
extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);

extern struct tty_ldisc *tty_ldisc_get(int);
extern void tty_ldisc_put(int);

extern void tty_wakeup(struct tty_struct *tty);
extern void tty_ldisc_flush(struct tty_struct *tty);

extern struct mutex tty_mutex;

/* n_tty.c */
extern struct tty_ldisc tty_ldisc_N_TTY;

/* tty_ioctl.c */
extern int n_tty_ioctl(struct tty_struct * tty, struct file * file,
		       unsigned int cmd, unsigned long arg);

/* serial.c */

extern void serial_console_init(void);
 
/* pcxx.c */

extern int pcxe_open(struct tty_struct *tty, struct file *filp);

/* printk.c */

extern void console_print(const char *);

/* vt.c */

extern int vt_ioctl(struct tty_struct *tty, struct file * file,
		    unsigned int cmd, unsigned long arg);

static inline dev_t tty_devnum(struct tty_struct *tty)
{
	return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index;
}

#endif /* __KERNEL__ */
#endif