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#ifndef _LINUX_TTY_DRIVER_H
#define _LINUX_TTY_DRIVER_H
/*
* This structure defines the interface between the low-level tty
* driver and the tty routines. The following routines can be
* defined; unless noted otherwise, they are optional, and can be
* filled in with a null pointer.
*
* int (*open)(struct tty_struct * tty, struct file * filp);
*
* This routine is called when a particular tty device is opened.
* This routine is mandatory; if this routine is not filled in,
* the attempted open will fail with ENODEV.
*
* void (*close)(struct tty_struct * tty, struct file * filp);
*
* This routine is called when a particular tty device is closed.
*
* int (*write)(struct tty_struct * tty, int from_user,
* unsigned char *buf, int count);
*
* This routine is called by the kernel to write a series of
* characters to the tty device. The characters may come from
* user space or kernel space. This routine will return the
* number of characters actually accepted for writing. This
* routine is mandatory.
*
* void (*put_char)(struct tty_struct *tty, unsigned char ch);
*
* This routine is called by the kernel to write a single
* character to the tty device. If the kernel uses this routine,
* it must call the flush_chars() routine (if defined) when it is
* done stuffing characters into the driver. If there is no room
* in the queue, the character is ignored.
*
* void (*flush_chars)(struct tty_struct *tty);
*
* This routine is called by the kernel after it has written a
* series of characters to the tty device using put_char().
*
* int (*write_room)(struct tty_struct *tty);
*
* This routine returns the numbers of characters the tty driver
* will accept for queuing to be written. This number is subject
* to change as output buffers get emptied, or if the output flow
* control is acted.
*
* int (*ioctl)(struct tty_struct *tty, struct file * file,
* unsigned int cmd, unsigned long arg);
*
* This routine allows the tty driver to implement
* device-specific ioctl's. If the ioctl number passed in cmd
* is not recognized by the driver, it should return ENOIOCTLCMD.
*
* void (*set_termios)(struct tty_struct *tty, struct termios * old);
*
* This routine allows the tty driver to be notified when
* device's termios settings have changed. Note that a
* well-designed tty driver should be prepared to accept the case
* where old == NULL, and try to do something rational.
*
* void (*set_ldisc)(struct tty_struct *tty);
*
* This routine allows the tty driver to be notified when the
* device's termios settings have changed.
*
* void (*throttle)(struct tty_struct * tty);
*
* This routine notifies the tty driver that input buffers for
* the line discipline are close to full, and it should somehow
* signal that no more characters should be sent to the tty.
*
* void (*unthrottle)(struct tty_struct * tty);
*
* This routine notifies the tty drivers that it should signals
* that characters can now be sent to the tty without fear of
* overrunning the input buffers of the line disciplines.
*
* void (*stop)(struct tty_struct *tty);
*
* This routine notifies the tty driver that it should stop
* outputting characters to the tty device.
*
* void (*start)(struct tty_struct *tty);
*
* This routine notifies the tty driver that it resume sending
* characters to the tty device.
*
* void (*hangup)(struct tty_struct *tty);
*
* This routine notifies the tty driver that it should hangup the
* tty device.
*
*/
#include <linux/fs.h>
struct tty_driver {
int magic; /* magic number for this structure */
char *name;
int name_base; /* offset of printed name */
short major; /* major device number */
short minor_start; /* start of minor device number*/
short num; /* number of devices */
short type; /* type of tty driver */
short subtype; /* subtype of tty driver */
struct termios init_termios; /* Initial termios */
int flags; /* tty driver flags */
int *refcount; /* for loadable tty drivers */
struct tty_driver *other; /* only used for the PTY driver */
/*
* Pointer to the tty data structures
*/
struct tty_struct **table;
struct termios **termios;
struct termios **termios_locked;
/*
* Interface routines from the upper tty layer to the tty
* driver.
*/
int (*open)(struct tty_struct * tty, struct file * filp);
void (*close)(struct tty_struct * tty, struct file * filp);
int (*write)(struct tty_struct * tty, int from_user,
unsigned char *buf, int count);
void (*put_char)(struct tty_struct *tty, unsigned char ch);
void (*flush_chars)(struct tty_struct *tty);
int (*write_room)(struct tty_struct *tty);
int (*chars_in_buffer)(struct tty_struct *tty);
int (*ioctl)(struct tty_struct *tty, struct file * file,
unsigned int cmd, unsigned long arg);
void (*set_termios)(struct tty_struct *tty, struct termios * old);
void (*throttle)(struct tty_struct * tty);
void (*unthrottle)(struct tty_struct * tty);
void (*stop)(struct tty_struct *tty);
void (*start)(struct tty_struct *tty);
void (*hangup)(struct tty_struct *tty);
void (*flush_buffer)(struct tty_struct *tty);
void (*set_ldisc)(struct tty_struct *tty);
/*
* linked list pointers
*/
struct tty_driver *next;
struct tty_driver *prev;
};
/* tty driver magic number */
#define TTY_DRIVER_MAGIC 0x5402
/*
* tty driver flags
*
* TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the
* termios setting when the last process has closed the device.
* Used for PTY's, in particular.
*
* TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will
* guarantee never not to set any special character handling
* flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR ||
* !INPCK)). That is, if there is no reason for the driver to
* send notifications of parity and break characters up to the
* line driver, it won't do so. This allows the line driver to
* optimize for this case if this flag is set. (Note that there
* is also a promise, if the above case is true, not to signal
* overruns, either.)
*/
#define TTY_DRIVER_INSTALLED 0x0001
#define TTY_DRIVER_RESET_TERMIOS 0x0002
#define TTY_DRIVER_REAL_RAW 0x0004
/* tty driver types */
#define TTY_DRIVER_TYPE_SYSTEM 0x0001
#define TTY_DRIVER_TYPE_CONSOLE 0x0002
#define TTY_DRIVER_TYPE_SERIAL 0x0003
#define TTY_DRIVER_TYPE_PTY 0x0004
/* system subtypes (magic, used by tty_io.c) */
#define SYSTEM_TYPE_TTY 0x0001
#define SYSTEM_TYPE_CONSOLE 0x0002
/* pty subtypes (magic, used by tty_io.c) */
#define PTY_TYPE_MASTER 0x0001
#define PTY_TYPE_SLAVE 0x0002
#endif /* #ifdef _LINUX_TTY_DRIVER_H */
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