1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_TTY_DRIVER_H
3 #define _LINUX_TTY_DRIVER_H
4
5 #include <linux/export.h>
6 #include <linux/fs.h>
7 #include <linux/kref.h>
8 #include <linux/list.h>
9 #include <linux/cdev.h>
10 #include <linux/uaccess.h>
11 #include <linux/termios.h>
12 #include <linux/seq_file.h>
13
14 struct tty_struct;
15 struct tty_driver;
16 struct serial_icounter_struct;
17 struct serial_struct;
18
19 /**
20 * struct tty_operations -- interface between driver and tty
21 *
22 * @lookup: ``struct tty_struct *()(struct tty_driver *self, struct file *,
23 * int idx)``
24 *
25 * Return the tty device corresponding to @idx, %NULL if there is not
26 * one currently in use and an %ERR_PTR value on error. Called under
27 * %tty_mutex (for now!)
28 *
29 * Optional method. Default behaviour is to use the @self->ttys array.
30 *
31 * @install: ``int ()(struct tty_driver *self, struct tty_struct *tty)``
32 *
33 * Install a new @tty into the @self's internal tables. Used in
34 * conjunction with @lookup and @remove methods.
35 *
36 * Optional method. Default behaviour is to use the @self->ttys array.
37 *
38 * @remove: ``void ()(struct tty_driver *self, struct tty_struct *tty)``
39 *
40 * Remove a closed @tty from the @self's internal tables. Used in
41 * conjunction with @lookup and @remove methods.
42 *
43 * Optional method. Default behaviour is to use the @self->ttys array.
44 *
45 * @open: ``int ()(struct tty_struct *tty, struct file *)``
46 *
47 * This routine is called when a particular @tty device is opened. This
48 * routine is mandatory; if this routine is not filled in, the attempted
49 * open will fail with %ENODEV.
50 *
51 * Required method. Called with tty lock held. May sleep.
52 *
53 * @close: ``void ()(struct tty_struct *tty, struct file *)``
54 *
55 * This routine is called when a particular @tty device is closed. At the
56 * point of return from this call the driver must make no further ldisc
57 * calls of any kind.
58 *
59 * Remark: called even if the corresponding @open() failed.
60 *
61 * Required method. Called with tty lock held. May sleep.
62 *
63 * @shutdown: ``void ()(struct tty_struct *tty)``
64 *
65 * This routine is called under the tty lock when a particular @tty device
66 * is closed for the last time. It executes before the @tty resources
67 * are freed so may execute while another function holds a @tty kref.
68 *
69 * @cleanup: ``void ()(struct tty_struct *tty)``
70 *
71 * This routine is called asynchronously when a particular @tty device
72 * is closed for the last time freeing up the resources. This is
73 * actually the second part of shutdown for routines that might sleep.
74 *
75 * @write: ``ssize_t ()(struct tty_struct *tty, const u8 *buf, size_t count)``
76 *
77 * This routine is called by the kernel to write a series (@count) of
78 * characters (@buf) to the @tty device. The characters may come from
79 * user space or kernel space. This routine will return the
80 * number of characters actually accepted for writing.
81 *
82 * May occur in parallel in special cases. Because this includes panic
83 * paths drivers generally shouldn't try and do clever locking here.
84 *
85 * Optional: Required for writable devices. May not sleep.
86 *
87 * @put_char: ``int ()(struct tty_struct *tty, u8 ch)``
88 *
89 * This routine is called by the kernel to write a single character @ch to
90 * the @tty device. If the kernel uses this routine, it must call the
91 * @flush_chars() routine (if defined) when it is done stuffing characters
92 * into the driver. If there is no room in the queue, the character is
93 * ignored.
94 *
95 * Optional: Kernel will use the @write method if not provided. Do not
96 * call this function directly, call tty_put_char().
97 *
98 * @flush_chars: ``void ()(struct tty_struct *tty)``
99 *
100 * This routine is called by the kernel after it has written a
101 * series of characters to the tty device using @put_char().
102 *
103 * Optional. Do not call this function directly, call
104 * tty_driver_flush_chars().
105 *
106 * @write_room: ``unsigned int ()(struct tty_struct *tty)``
107 *
108 * This routine returns the numbers of characters the @tty driver
109 * will accept for queuing to be written. This number is subject
110 * to change as output buffers get emptied, or if the output flow
111 * control is acted.
112 *
113 * The ldisc is responsible for being intelligent about multi-threading of
114 * write_room/write calls
115 *
116 * Required if @write method is provided else not needed. Do not call this
117 * function directly, call tty_write_room()
118 *
119 * @chars_in_buffer: ``unsigned int ()(struct tty_struct *tty)``
120 *
121 * This routine returns the number of characters in the device private
122 * output queue. Used in tty_wait_until_sent() and for poll()
123 * implementation.
124 *
125 * Optional: if not provided, it is assumed there is no queue on the
126 * device. Do not call this function directly, call tty_chars_in_buffer().
127 *
128 * @ioctl: ``int ()(struct tty_struct *tty, unsigned int cmd,
129 * unsigned long arg)``
130 *
131 * This routine allows the @tty driver to implement device-specific
132 * ioctls. If the ioctl number passed in @cmd is not recognized by the
133 * driver, it should return %ENOIOCTLCMD.
134 *
135 * Optional.
136 *
137 * @compat_ioctl: ``long ()(struct tty_struct *tty, unsigned int cmd,
138 * unsigned long arg)``
139 *
140 * Implement ioctl processing for 32 bit process on 64 bit system.
141 *
142 * Optional.
143 *
144 * @set_termios: ``void ()(struct tty_struct *tty, const struct ktermios *old)``
145 *
146 * This routine allows the @tty driver to be notified when device's
147 * termios settings have changed. New settings are in @tty->termios.
148 * Previous settings are passed in the @old argument.
149 *
150 * The API is defined such that the driver should return the actual modes
151 * selected. This means that the driver is responsible for modifying any
152 * bits in @tty->termios it cannot fulfill to indicate the actual modes
153 * being used.
154 *
155 * Optional. Called under the @tty->termios_rwsem. May sleep.
156 *
157 * @ldisc_ok: ``int ()(struct tty_struct *tty, int ldisc)``
158 *
159 * This routine allows the @tty driver to decide if it can deal
160 * with a particular @ldisc.
161 *
162 * Optional. Called under the @tty->ldisc_sem and @tty->termios_rwsem.
163 *
164 * @set_ldisc: ``void ()(struct tty_struct *tty)``
165 *
166 * This routine allows the @tty driver to be notified when the device's
167 * line discipline is being changed. At the point this is done the
168 * discipline is not yet usable.
169 *
170 * Optional. Called under the @tty->ldisc_sem and @tty->termios_rwsem.
171 *
172 * @throttle: ``void ()(struct tty_struct *tty)``
173 *
174 * This routine notifies the @tty driver that input buffers for the line
175 * discipline are close to full, and it should somehow signal that no more
176 * characters should be sent to the @tty.
177 *
178 * Serialization including with @unthrottle() is the job of the ldisc
179 * layer.
180 *
181 * Optional: Always invoke via tty_throttle_safe(). Called under the
182 * @tty->termios_rwsem.
183 *
184 * @unthrottle: ``void ()(struct tty_struct *tty)``
185 *
186 * This routine notifies the @tty driver that it should signal that
187 * characters can now be sent to the @tty without fear of overrunning the
188 * input buffers of the line disciplines.
189 *
190 * Optional. Always invoke via tty_unthrottle(). Called under the
191 * @tty->termios_rwsem.
192 *
193 * @stop: ``void ()(struct tty_struct *tty)``
194 *
195 * This routine notifies the @tty driver that it should stop outputting
196 * characters to the tty device.
197 *
198 * Called with @tty->flow.lock held. Serialized with @start() method.
199 *
200 * Optional. Always invoke via stop_tty().
201 *
202 * @start: ``void ()(struct tty_struct *tty)``
203 *
204 * This routine notifies the @tty driver that it resumed sending
205 * characters to the @tty device.
206 *
207 * Called with @tty->flow.lock held. Serialized with stop() method.
208 *
209 * Optional. Always invoke via start_tty().
210 *
211 * @hangup: ``void ()(struct tty_struct *tty)``
212 *
213 * This routine notifies the @tty driver that it should hang up the @tty
214 * device.
215 *
216 * Optional. Called with tty lock held.
217 *
218 * @break_ctl: ``int ()(struct tty_struct *tty, int state)``
219 *
220 * This optional routine requests the @tty driver to turn on or off BREAK
221 * status on the RS-232 port. If @state is -1, then the BREAK status
222 * should be turned on; if @state is 0, then BREAK should be turned off.
223 *
224 * If this routine is implemented, the high-level tty driver will handle
225 * the following ioctls: %TCSBRK, %TCSBRKP, %TIOCSBRK, %TIOCCBRK.
226 *
227 * If the driver sets %TTY_DRIVER_HARDWARE_BREAK in tty_alloc_driver(),
228 * then the interface will also be called with actual times and the
229 * hardware is expected to do the delay work itself. 0 and -1 are still
230 * used for on/off.
231 *
232 * Optional: Required for %TCSBRK/%BRKP/etc. handling. May sleep.
233 *
234 * @flush_buffer: ``void ()(struct tty_struct *tty)``
235 *
236 * This routine discards device private output buffer. Invoked on close,
237 * hangup, to implement %TCOFLUSH ioctl and similar.
238 *
239 * Optional: if not provided, it is assumed there is no queue on the
240 * device. Do not call this function directly, call
241 * tty_driver_flush_buffer().
242 *
243 * @wait_until_sent: ``void ()(struct tty_struct *tty, int timeout)``
244 *
245 * This routine waits until the device has written out all of the
246 * characters in its transmitter FIFO. Or until @timeout (in jiffies) is
247 * reached.
248 *
249 * Optional: If not provided, the device is assumed to have no FIFO.
250 * Usually correct to invoke via tty_wait_until_sent(). May sleep.
251 *
252 * @send_xchar: ``void ()(struct tty_struct *tty, u8 ch)``
253 *
254 * This routine is used to send a high-priority XON/XOFF character (@ch)
255 * to the @tty device.
256 *
257 * Optional: If not provided, then the @write method is called under
258 * the @tty->atomic_write_lock to keep it serialized with the ldisc.
259 *
260 * @tiocmget: ``int ()(struct tty_struct *tty)``
261 *
262 * This routine is used to obtain the modem status bits from the @tty
263 * driver.
264 *
265 * Optional: If not provided, then %ENOTTY is returned from the %TIOCMGET
266 * ioctl. Do not call this function directly, call tty_tiocmget().
267 *
268 * @tiocmset: ``int ()(struct tty_struct *tty,
269 * unsigned int set, unsigned int clear)``
270 *
271 * This routine is used to set the modem status bits to the @tty driver.
272 * First, @clear bits should be cleared, then @set bits set.
273 *
274 * Optional: If not provided, then %ENOTTY is returned from the %TIOCMSET
275 * ioctl. Do not call this function directly, call tty_tiocmset().
276 *
277 * @resize: ``int ()(struct tty_struct *tty, struct winsize *ws)``
278 *
279 * Called when a termios request is issued which changes the requested
280 * terminal geometry to @ws.
281 *
282 * Optional: the default action is to update the termios structure
283 * without error. This is usually the correct behaviour. Drivers should
284 * not force errors here if they are not resizable objects (e.g. a serial
285 * line). See tty_do_resize() if you need to wrap the standard method
286 * in your own logic -- the usual case.
287 *
288 * @get_icount: ``int ()(struct tty_struct *tty,
289 * struct serial_icounter *icount)``
290 *
291 * Called when the @tty device receives a %TIOCGICOUNT ioctl. Passed a
292 * kernel structure @icount to complete.
293 *
294 * Optional: called only if provided, otherwise %ENOTTY will be returned.
295 *
296 * @get_serial: ``int ()(struct tty_struct *tty, struct serial_struct *p)``
297 *
298 * Called when the @tty device receives a %TIOCGSERIAL ioctl. Passed a
299 * kernel structure @p (&struct serial_struct) to complete.
300 *
301 * Optional: called only if provided, otherwise %ENOTTY will be returned.
302 * Do not call this function directly, call tty_tiocgserial().
303 *
304 * @set_serial: ``int ()(struct tty_struct *tty, struct serial_struct *p)``
305 *
306 * Called when the @tty device receives a %TIOCSSERIAL ioctl. Passed a
307 * kernel structure @p (&struct serial_struct) to set the values from.
308 *
309 * Optional: called only if provided, otherwise %ENOTTY will be returned.
310 * Do not call this function directly, call tty_tiocsserial().
311 *
312 * @show_fdinfo: ``void ()(struct tty_struct *tty, struct seq_file *m)``
313 *
314 * Called when the @tty device file descriptor receives a fdinfo request
315 * from VFS (to show in /proc/<pid>/fdinfo/). @m should be filled with
316 * information.
317 *
318 * Optional: called only if provided, otherwise nothing is written to @m.
319 * Do not call this function directly, call tty_show_fdinfo().
320 *
321 * @poll_init: ``int ()(struct tty_driver *driver, int line, char *options)``
322 *
323 * kgdboc support (Documentation/dev-tools/kgdb.rst). This routine is
324 * called to initialize the HW for later use by calling @poll_get_char or
325 * @poll_put_char.
326 *
327 * Optional: called only if provided, otherwise skipped as a non-polling
328 * driver.
329 *
330 * @poll_get_char: ``int ()(struct tty_driver *driver, int line)``
331 *
332 * kgdboc support (see @poll_init). @driver should read a character from a
333 * tty identified by @line and return it.
334 *
335 * Optional: called only if @poll_init provided.
336 *
337 * @poll_put_char: ``void ()(struct tty_driver *driver, int line, char ch)``
338 *
339 * kgdboc support (see @poll_init). @driver should write character @ch to
340 * a tty identified by @line.
341 *
342 * Optional: called only if @poll_init provided.
343 *
344 * @proc_show: ``int ()(struct seq_file *m, void *driver)``
345 *
346 * Driver @driver (cast to &struct tty_driver) can show additional info in
347 * /proc/tty/driver/<driver_name>. It is enough to fill in the information
348 * into @m.
349 *
350 * Optional: called only if provided, otherwise no /proc entry created.
351 *
352 * This structure defines the interface between the low-level tty driver and
353 * the tty routines. These routines can be defined. Unless noted otherwise,
354 * they are optional, and can be filled in with a %NULL pointer.
355 */
356 struct tty_operations {
357 struct tty_struct * (*lookup)(struct tty_driver *driver,
358 struct file *filp, int idx);
359 int (*install)(struct tty_driver *driver, struct tty_struct *tty);
360 void (*remove)(struct tty_driver *driver, struct tty_struct *tty);
361 int (*open)(struct tty_struct * tty, struct file * filp);
362 void (*close)(struct tty_struct * tty, struct file * filp);
363 void (*shutdown)(struct tty_struct *tty);
364 void (*cleanup)(struct tty_struct *tty);
365 ssize_t (*write)(struct tty_struct *tty, const u8 *buf, size_t count);
366 int (*put_char)(struct tty_struct *tty, u8 ch);
367 void (*flush_chars)(struct tty_struct *tty);
368 unsigned int (*write_room)(struct tty_struct *tty);
369 unsigned int (*chars_in_buffer)(struct tty_struct *tty);
370 int (*ioctl)(struct tty_struct *tty,
371 unsigned int cmd, unsigned long arg);
372 long (*compat_ioctl)(struct tty_struct *tty,
373 unsigned int cmd, unsigned long arg);
374 void (*set_termios)(struct tty_struct *tty, const struct ktermios *old);
375 void (*throttle)(struct tty_struct * tty);
376 void (*unthrottle)(struct tty_struct * tty);
377 void (*stop)(struct tty_struct *tty);
378 void (*start)(struct tty_struct *tty);
379 void (*hangup)(struct tty_struct *tty);
380 int (*break_ctl)(struct tty_struct *tty, int state);
381 void (*flush_buffer)(struct tty_struct *tty);
382 int (*ldisc_ok)(struct tty_struct *tty, int ldisc);
383 void (*set_ldisc)(struct tty_struct *tty);
384 void (*wait_until_sent)(struct tty_struct *tty, int timeout);
385 void (*send_xchar)(struct tty_struct *tty, u8 ch);
386 int (*tiocmget)(struct tty_struct *tty);
387 int (*tiocmset)(struct tty_struct *tty,
388 unsigned int set, unsigned int clear);
389 int (*resize)(struct tty_struct *tty, struct winsize *ws);
390 int (*get_icount)(struct tty_struct *tty,
391 struct serial_icounter_struct *icount);
392 int (*get_serial)(struct tty_struct *tty, struct serial_struct *p);
393 int (*set_serial)(struct tty_struct *tty, struct serial_struct *p);
394 void (*show_fdinfo)(struct tty_struct *tty, struct seq_file *m);
395 #ifdef CONFIG_CONSOLE_POLL
396 int (*poll_init)(struct tty_driver *driver, int line, char *options);
397 int (*poll_get_char)(struct tty_driver *driver, int line);
398 void (*poll_put_char)(struct tty_driver *driver, int line, char ch);
399 #endif
400 int (*proc_show)(struct seq_file *m, void *driver);
401 } __randomize_layout;
402
403 /**
404 * struct tty_driver -- driver for TTY devices
405 *
406 * @kref: reference counting. Reaching zero frees all the internals and the
407 * driver.
408 * @cdevs: allocated/registered character /dev devices
409 * @owner: modules owning this driver. Used drivers cannot be rmmod'ed.
410 * Automatically set by tty_alloc_driver().
411 * @driver_name: name of the driver used in /proc/tty
412 * @name: used for constructing /dev node name
413 * @name_base: used as a number base for constructing /dev node name
414 * @major: major /dev device number (zero for autoassignment)
415 * @minor_start: the first minor /dev device number
416 * @num: number of devices allocated
417 * @type: type of tty driver (%TTY_DRIVER_TYPE_)
418 * @subtype: subtype of tty driver (%SYSTEM_TYPE_, %PTY_TYPE_, %SERIAL_TYPE_)
419 * @init_termios: termios to set to each tty initially (e.g. %tty_std_termios)
420 * @flags: tty driver flags (%TTY_DRIVER_)
421 * @proc_entry: proc fs entry, used internally
422 * @other: driver of the linked tty; only used for the PTY driver
423 * @ttys: array of active &struct tty_struct, set by tty_standard_install()
424 * @ports: array of &struct tty_port; can be set during initialization by
425 * tty_port_link_device() and similar
426 * @termios: storage for termios at each TTY close for the next open
427 * @driver_state: pointer to driver's arbitrary data
428 * @ops: driver hooks for TTYs. Set them using tty_set_operations(). Use &struct
429 * tty_port helpers in them as much as possible.
430 * @tty_drivers: used internally to link tty_drivers together
431 *
432 * The usual handling of &struct tty_driver is to allocate it by
433 * tty_alloc_driver(), set up all the necessary members, and register it by
434 * tty_register_driver(). At last, the driver is torn down by calling
435 * tty_unregister_driver() followed by tty_driver_kref_put().
436 *
437 * The fields required to be set before calling tty_register_driver() include
438 * @driver_name, @name, @type, @subtype, @init_termios, and @ops.
439 */
440 struct tty_driver {
441 struct kref kref;
442 struct cdev **cdevs;
443 struct module *owner;
444 const char *driver_name;
445 const char *name;
446 int name_base;
447 int major;
448 int minor_start;
449 unsigned int num;
450 short type;
451 short subtype;
452 struct ktermios init_termios;
453 unsigned long flags;
454 struct proc_dir_entry *proc_entry;
455 struct tty_driver *other;
456
457 /*
458 * Pointer to the tty data structures
459 */
460 struct tty_struct **ttys;
461 struct tty_port **ports;
462 struct ktermios **termios;
463 void *driver_state;
464
465 /*
466 * Driver methods
467 */
468
469 const struct tty_operations *ops;
470 struct list_head tty_drivers;
471 } __randomize_layout;
472
473 extern struct list_head tty_drivers;
474
475 struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner,
476 unsigned long flags);
477 struct tty_driver *tty_find_polling_driver(char *name, int *line);
478
479 void tty_driver_kref_put(struct tty_driver *driver);
480
481 /* Use TTY_DRIVER_* flags below */
482 #define tty_alloc_driver(lines, flags) \
483 __tty_alloc_driver(lines, THIS_MODULE, flags)
484
485 static inline struct tty_driver *tty_driver_kref_get(struct tty_driver *d)
486 {
487 kref_get(&d->kref);
488 return d;
489 }
490
491 static inline void tty_set_operations(struct tty_driver *driver,
492 const struct tty_operations *op)
493 {
494 driver->ops = op;
495 }
496
497 /**
498 * DOC: TTY Driver Flags
499 *
500 * TTY_DRIVER_RESET_TERMIOS
501 * Requests the tty layer to reset the termios setting when the last
502 * process has closed the device. Used for PTYs, in particular.
503 *
504 * TTY_DRIVER_REAL_RAW
505 * Indicates that the driver will guarantee not to set any special
506 * character handling flags if this is set for the tty:
507 *
508 * ``(IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR || !INPCK)``
509 *
510 * That is, if there is no reason for the driver to
511 * send notifications of parity and break characters up to the line
512 * driver, it won't do so. This allows the line driver to optimize for
513 * this case if this flag is set. (Note that there is also a promise, if
514 * the above case is true, not to signal overruns, either.)
515 *
516 * TTY_DRIVER_DYNAMIC_DEV
517 * The individual tty devices need to be registered with a call to
518 * tty_register_device() when the device is found in the system and
519 * unregistered with a call to tty_unregister_device() so the devices will
520 * be show up properly in sysfs. If not set, all &tty_driver.num entries
521 * will be created by the tty core in sysfs when tty_register_driver() is
522 * called. This is to be used by drivers that have tty devices that can
523 * appear and disappear while the main tty driver is registered with the
524 * tty core.
525 *
526 * TTY_DRIVER_DEVPTS_MEM
527 * Don't use the standard arrays (&tty_driver.ttys and
528 * &tty_driver.termios), instead use dynamic memory keyed through the
529 * devpts filesystem. This is only applicable to the PTY driver.
530 *
531 * TTY_DRIVER_HARDWARE_BREAK
532 * Hardware handles break signals. Pass the requested timeout to the
533 * &tty_operations.break_ctl instead of using a simple on/off interface.
534 *
535 * TTY_DRIVER_DYNAMIC_ALLOC
536 * Do not allocate structures which are needed per line for this driver
537 * (&tty_driver.ports) as it would waste memory. The driver will take
538 * care. This is only applicable to the PTY driver.
539 *
540 * TTY_DRIVER_UNNUMBERED_NODE
541 * Do not create numbered ``/dev`` nodes. For example, create
542 * ``/dev/ttyprintk`` and not ``/dev/ttyprintk0``. Applicable only when a
543 * driver for a single tty device is being allocated.
544 */
545 #define TTY_DRIVER_INSTALLED 0x0001
546 #define TTY_DRIVER_RESET_TERMIOS 0x0002
547 #define TTY_DRIVER_REAL_RAW 0x0004
548 #define TTY_DRIVER_DYNAMIC_DEV 0x0008
549 #define TTY_DRIVER_DEVPTS_MEM 0x0010
550 #define TTY_DRIVER_HARDWARE_BREAK 0x0020
551 #define TTY_DRIVER_DYNAMIC_ALLOC 0x0040
552 #define TTY_DRIVER_UNNUMBERED_NODE 0x0080
553
554 /* tty driver types */
555 #define TTY_DRIVER_TYPE_SYSTEM 0x0001
556 #define TTY_DRIVER_TYPE_CONSOLE 0x0002
557 #define TTY_DRIVER_TYPE_SERIAL 0x0003
558 #define TTY_DRIVER_TYPE_PTY 0x0004
559 #define TTY_DRIVER_TYPE_SCC 0x0005 /* scc driver */
560 #define TTY_DRIVER_TYPE_SYSCONS 0x0006
561
562 /* system subtypes (magic, used by tty_io.c) */
563 #define SYSTEM_TYPE_TTY 0x0001
564 #define SYSTEM_TYPE_CONSOLE 0x0002
565 #define SYSTEM_TYPE_SYSCONS 0x0003
566 #define SYSTEM_TYPE_SYSPTMX 0x0004
567
568 /* pty subtypes (magic, used by tty_io.c) */
569 #define PTY_TYPE_MASTER 0x0001
570 #define PTY_TYPE_SLAVE 0x0002
571
572 /* serial subtype definitions */
573 #define SERIAL_TYPE_NORMAL 1
574
575 int tty_register_driver(struct tty_driver *driver);
576 void tty_unregister_driver(struct tty_driver *driver);
577 struct device *tty_register_device(struct tty_driver *driver, unsigned index,
578 struct device *dev);
579 struct device *tty_register_device_attr(struct tty_driver *driver,
580 unsigned index, struct device *device, void *drvdata,
581 const struct attribute_group **attr_grp);
582 void tty_unregister_device(struct tty_driver *driver, unsigned index);
583
584 #ifdef CONFIG_PROC_FS
585 void proc_tty_register_driver(struct tty_driver *);
586 void proc_tty_unregister_driver(struct tty_driver *);
587 #else
588 static inline void proc_tty_register_driver(struct tty_driver *d) {}
589 static inline void proc_tty_unregister_driver(struct tty_driver *d) {}
590 #endif
591
592 #endif /* #ifdef _LINUX_TTY_DRIVER_H */
593
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