1 #ifndef _LINUX_TTY_DRIVER_H
2 #define _LINUX_TTY_DRIVER_H
5 * This structure defines the interface between the low-level tty
6 * driver and the tty routines. The following routines can be
7 * defined; unless noted otherwise, they are optional, and can be
8 * filled in with a null pointer.
10 * struct tty_struct * (*lookup)(struct tty_driver *self, int idx)
12 * Return the tty device corresponding to idx, NULL if there is not
13 * one currently in use and an ERR_PTR value on error. Called under
14 * tty_mutex (for now!)
16 * Optional method. Default behaviour is to use the ttys array
18 * int (*install)(struct tty_driver *self, struct tty_struct *tty)
20 * Install a new tty into the tty driver internal tables. Used in
21 * conjunction with lookup and remove methods.
23 * Optional method. Default behaviour is to use the ttys array
25 * void (*remove)(struct tty_driver *self, struct tty_struct *tty)
27 * Remove a closed tty from the tty driver internal tables. Used in
28 * conjunction with lookup and remove methods.
30 * Optional method. Default behaviour is to use the ttys array
32 * int (*open)(struct tty_struct * tty, struct file * filp);
34 * This routine is called when a particular tty device is opened.
35 * This routine is mandatory; if this routine is not filled in,
36 * the attempted open will fail with ENODEV.
40 * void (*close)(struct tty_struct * tty, struct file * filp);
42 * This routine is called when a particular tty device is closed.
46 * void (*shutdown)(struct tty_struct * tty);
48 * This routine is called synchronously when a particular tty device
49 * is closed for the last time freeing up the resources.
50 * Note that tty_shutdown() is not called if ops->shutdown is defined.
51 * This means one is responsible to take care of calling ops->remove (e.g.
52 * via tty_driver_remove_tty) and releasing tty->termios.
53 * Note that this hook may be called from *all* the contexts where one
54 * uses tty refcounting (e.g. tty_port_tty_get).
57 * void (*cleanup)(struct tty_struct * tty);
59 * This routine is called asynchronously when a particular tty device
60 * is closed for the last time freeing up the resources. This is
61 * actually the second part of shutdown for routines that might sleep.
64 * int (*write)(struct tty_struct * tty,
65 * const unsigned char *buf, int count);
67 * This routine is called by the kernel to write a series of
68 * characters to the tty device. The characters may come from
69 * user space or kernel space. This routine will return the
70 * number of characters actually accepted for writing.
72 * Optional: Required for writable devices.
74 * int (*put_char)(struct tty_struct *tty, unsigned char ch);
76 * This routine is called by the kernel to write a single
77 * character to the tty device. If the kernel uses this routine,
78 * it must call the flush_chars() routine (if defined) when it is
79 * done stuffing characters into the driver. If there is no room
80 * in the queue, the character is ignored.
82 * Optional: Kernel will use the write method if not provided.
84 * Note: Do not call this function directly, call tty_put_char
86 * void (*flush_chars)(struct tty_struct *tty);
88 * This routine is called by the kernel after it has written a
89 * series of characters to the tty device using put_char().
93 * Note: Do not call this function directly, call tty_driver_flush_chars
95 * int (*write_room)(struct tty_struct *tty);
97 * This routine returns the numbers of characters the tty driver
98 * will accept for queuing to be written. This number is subject
99 * to change as output buffers get emptied, or if the output flow
102 * Required if write method is provided else not needed.
104 * Note: Do not call this function directly, call tty_write_room
106 * int (*ioctl)(struct tty_struct *tty, unsigned int cmd, unsigned long arg);
108 * This routine allows the tty driver to implement
109 * device-specific ioctls. If the ioctl number passed in cmd
110 * is not recognized by the driver, it should return ENOIOCTLCMD.
114 * long (*compat_ioctl)(struct tty_struct *tty,,
115 * unsigned int cmd, unsigned long arg);
117 * implement ioctl processing for 32 bit process on 64 bit system
121 * void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
123 * This routine allows the tty driver to be notified when
124 * device's termios settings have changed.
126 * Optional: Called under the termios lock
129 * void (*set_ldisc)(struct tty_struct *tty);
131 * This routine allows the tty driver to be notified when the
132 * device's termios settings have changed.
134 * Optional: Called under BKL (currently)
136 * void (*throttle)(struct tty_struct * tty);
138 * This routine notifies the tty driver that input buffers for
139 * the line discipline are close to full, and it should somehow
140 * signal that no more characters should be sent to the tty.
142 * Optional: Always invoke via tty_throttle(), called under the
145 * void (*unthrottle)(struct tty_struct * tty);
147 * This routine notifies the tty drivers that it should signals
148 * that characters can now be sent to the tty without fear of
149 * overrunning the input buffers of the line disciplines.
151 * Optional: Always invoke via tty_unthrottle(), called under the
154 * void (*stop)(struct tty_struct *tty);
156 * This routine notifies the tty driver that it should stop
157 * outputting characters to the tty device.
161 * Note: Call stop_tty not this method.
163 * void (*start)(struct tty_struct *tty);
165 * This routine notifies the tty driver that it resume sending
166 * characters to the tty device.
170 * Note: Call start_tty not this method.
172 * void (*hangup)(struct tty_struct *tty);
174 * This routine notifies the tty driver that it should hang up the
179 * int (*break_ctl)(struct tty_struct *tty, int state);
181 * This optional routine requests the tty driver to turn on or
182 * off BREAK status on the RS-232 port. If state is -1,
183 * then the BREAK status should be turned on; if state is 0, then
184 * BREAK should be turned off.
186 * If this routine is implemented, the high-level tty driver will
187 * handle the following ioctls: TCSBRK, TCSBRKP, TIOCSBRK,
190 * If the driver sets TTY_DRIVER_HARDWARE_BREAK then the interface
191 * will also be called with actual times and the hardware is expected
192 * to do the delay work itself. 0 and -1 are still used for on/off.
194 * Optional: Required for TCSBRK/BRKP/etc handling.
196 * void (*wait_until_sent)(struct tty_struct *tty, int timeout);
198 * This routine waits until the device has written out all of the
199 * characters in its transmitter FIFO.
201 * Optional: If not provided the device is assumed to have no FIFO
203 * Note: Usually correct to call tty_wait_until_sent
205 * void (*send_xchar)(struct tty_struct *tty, char ch);
207 * This routine is used to send a high-priority XON/XOFF
208 * character to the device.
210 * Optional: If not provided then the write method is called under
211 * the atomic write lock to keep it serialized with the ldisc.
213 * int (*resize)(struct tty_struct *tty, struct winsize *ws)
215 * Called when a termios request is issued which changes the
216 * requested terminal geometry.
218 * Optional: the default action is to update the termios structure
219 * without error. This is usually the correct behaviour. Drivers should
220 * not force errors here if they are not resizable objects (eg a serial
221 * line). See tty_do_resize() if you need to wrap the standard method
222 * in your own logic - the usual case.
224 * void (*set_termiox)(struct tty_struct *tty, struct termiox *new);
226 * Called when the device receives a termiox based ioctl. Passes down
227 * the requested data from user space. This method will not be invoked
228 * unless the tty also has a valid tty->termiox pointer.
230 * Optional: Called under the termios lock
232 * int (*get_icount)(struct tty_struct *tty, struct serial_icounter *icount);
234 * Called when the device receives a TIOCGICOUNT ioctl. Passed a kernel
235 * structure to complete. This method is optional and will only be called
236 * if provided (otherwise EINVAL will be returned).
239 #include <linux/export.h>
240 #include <linux/fs.h>
241 #include <linux/list.h>
242 #include <linux/cdev.h>
243 #include <linux/termios.h>
247 struct serial_icounter_struct
;
249 struct tty_operations
{
250 struct tty_struct
* (*lookup
)(struct tty_driver
*driver
,
251 struct inode
*inode
, int idx
);
252 int (*install
)(struct tty_driver
*driver
, struct tty_struct
*tty
);
253 void (*remove
)(struct tty_driver
*driver
, struct tty_struct
*tty
);
254 int (*open
)(struct tty_struct
* tty
, struct file
* filp
);
255 void (*close
)(struct tty_struct
* tty
, struct file
* filp
);
256 void (*shutdown
)(struct tty_struct
*tty
);
257 void (*cleanup
)(struct tty_struct
*tty
);
258 int (*write
)(struct tty_struct
* tty
,
259 const unsigned char *buf
, int count
);
260 int (*put_char
)(struct tty_struct
*tty
, unsigned char ch
);
261 void (*flush_chars
)(struct tty_struct
*tty
);
262 int (*write_room
)(struct tty_struct
*tty
);
263 int (*chars_in_buffer
)(struct tty_struct
*tty
);
264 int (*ioctl
)(struct tty_struct
*tty
,
265 unsigned int cmd
, unsigned long arg
);
266 long (*compat_ioctl
)(struct tty_struct
*tty
,
267 unsigned int cmd
, unsigned long arg
);
268 void (*set_termios
)(struct tty_struct
*tty
, struct ktermios
* old
);
269 void (*throttle
)(struct tty_struct
* tty
);
270 void (*unthrottle
)(struct tty_struct
* tty
);
271 void (*stop
)(struct tty_struct
*tty
);
272 void (*start
)(struct tty_struct
*tty
);
273 void (*hangup
)(struct tty_struct
*tty
);
274 int (*break_ctl
)(struct tty_struct
*tty
, int state
);
275 void (*flush_buffer
)(struct tty_struct
*tty
);
276 void (*set_ldisc
)(struct tty_struct
*tty
);
277 void (*wait_until_sent
)(struct tty_struct
*tty
, int timeout
);
278 void (*send_xchar
)(struct tty_struct
*tty
, char ch
);
279 int (*tiocmget
)(struct tty_struct
*tty
);
280 int (*tiocmset
)(struct tty_struct
*tty
,
281 unsigned int set
, unsigned int clear
);
282 int (*resize
)(struct tty_struct
*tty
, struct winsize
*ws
);
283 int (*set_termiox
)(struct tty_struct
*tty
, struct termiox
*tnew
);
284 int (*get_icount
)(struct tty_struct
*tty
,
285 struct serial_icounter_struct
*icount
);
286 #ifdef CONFIG_CONSOLE_POLL
287 int (*poll_init
)(struct tty_driver
*driver
, int line
, char *options
);
288 int (*poll_get_char
)(struct tty_driver
*driver
, int line
);
289 void (*poll_put_char
)(struct tty_driver
*driver
, int line
, char ch
);
291 const struct file_operations
*proc_fops
;
295 int magic
; /* magic number for this structure */
296 struct kref kref
; /* Reference management */
298 struct module
*owner
;
299 const char *driver_name
;
301 int name_base
; /* offset of printed name */
302 int major
; /* major device number */
303 int minor_start
; /* start of minor device number */
304 int num
; /* number of devices allocated */
305 short type
; /* type of tty driver */
306 short subtype
; /* subtype of tty driver */
307 struct ktermios init_termios
; /* Initial termios */
308 int flags
; /* tty driver flags */
309 struct proc_dir_entry
*proc_entry
; /* /proc fs entry */
310 struct tty_driver
*other
; /* only used for the PTY driver */
313 * Pointer to the tty data structures
315 struct tty_struct
**ttys
;
316 struct ktermios
**termios
;
323 const struct tty_operations
*ops
;
324 struct list_head tty_drivers
;
327 extern struct list_head tty_drivers
;
329 extern struct tty_driver
*__alloc_tty_driver(int lines
, struct module
*owner
);
330 extern void put_tty_driver(struct tty_driver
*driver
);
331 extern void tty_set_operations(struct tty_driver
*driver
,
332 const struct tty_operations
*op
);
333 extern struct tty_driver
*tty_find_polling_driver(char *name
, int *line
);
335 extern void tty_driver_kref_put(struct tty_driver
*driver
);
337 #define alloc_tty_driver(lines) __alloc_tty_driver(lines, THIS_MODULE)
339 static inline struct tty_driver
*tty_driver_kref_get(struct tty_driver
*d
)
345 /* tty driver magic number */
346 #define TTY_DRIVER_MAGIC 0x5402
351 * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the
352 * termios setting when the last process has closed the device.
353 * Used for PTY's, in particular.
355 * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will
356 * guarantee never not to set any special character handling
357 * flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR ||
358 * !INPCK)). That is, if there is no reason for the driver to
359 * send notifications of parity and break characters up to the
360 * line driver, it won't do so. This allows the line driver to
361 * optimize for this case if this flag is set. (Note that there
362 * is also a promise, if the above case is true, not to signal
365 * TTY_DRIVER_DYNAMIC_DEV --- if set, the individual tty devices need
366 * to be registered with a call to tty_register_device() when the
367 * device is found in the system and unregistered with a call to
368 * tty_unregister_device() so the devices will be show up
369 * properly in sysfs. If not set, driver->num entries will be
370 * created by the tty core in sysfs when tty_register_driver() is
371 * called. This is to be used by drivers that have tty devices
372 * that can appear and disappear while the main tty driver is
373 * registered with the tty core.
375 * TTY_DRIVER_DEVPTS_MEM -- don't use the standard arrays, instead
376 * use dynamic memory keyed through the devpts filesystem. This
377 * is only applicable to the pty driver.
379 * TTY_DRIVER_HARDWARE_BREAK -- hardware handles break signals. Pass
380 * the requested timeout to the caller instead of using a simple
384 #define TTY_DRIVER_INSTALLED 0x0001
385 #define TTY_DRIVER_RESET_TERMIOS 0x0002
386 #define TTY_DRIVER_REAL_RAW 0x0004
387 #define TTY_DRIVER_DYNAMIC_DEV 0x0008
388 #define TTY_DRIVER_DEVPTS_MEM 0x0010
389 #define TTY_DRIVER_HARDWARE_BREAK 0x0020
391 /* tty driver types */
392 #define TTY_DRIVER_TYPE_SYSTEM 0x0001
393 #define TTY_DRIVER_TYPE_CONSOLE 0x0002
394 #define TTY_DRIVER_TYPE_SERIAL 0x0003
395 #define TTY_DRIVER_TYPE_PTY 0x0004
396 #define TTY_DRIVER_TYPE_SCC 0x0005 /* scc driver */
397 #define TTY_DRIVER_TYPE_SYSCONS 0x0006
399 /* system subtypes (magic, used by tty_io.c) */
400 #define SYSTEM_TYPE_TTY 0x0001
401 #define SYSTEM_TYPE_CONSOLE 0x0002
402 #define SYSTEM_TYPE_SYSCONS 0x0003
403 #define SYSTEM_TYPE_SYSPTMX 0x0004
405 /* pty subtypes (magic, used by tty_io.c) */
406 #define PTY_TYPE_MASTER 0x0001
407 #define PTY_TYPE_SLAVE 0x0002
409 /* serial subtype definitions */
410 #define SERIAL_TYPE_NORMAL 1
412 #endif /* #ifdef _LINUX_TTY_DRIVER_H */
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