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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_TTY_DRIVER_H
2#define _LINUX_TTY_DRIVER_H
3
4/*
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.
9 *
Alan Cox99f1fe12008-10-13 10:42:00 +010010 * struct tty_struct * (*lookup)(struct tty_driver *self, int idx)
11 *
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!)
15 *
16 * Optional method. Default behaviour is to use the ttys array
17 *
Alan Cox8b0a88d2008-10-13 10:42:19 +010018 * int (*install)(struct tty_driver *self, struct tty_struct *tty)
19 *
20 * Install a new tty into the tty driver internal tables. Used in
21 * conjunction with lookup and remove methods.
22 *
23 * Optional method. Default behaviour is to use the ttys array
24 *
25 * void (*remove)(struct tty_driver *self, struct tty_struct *tty)
26 *
27 * Remove a closed tty from the tty driver internal tables. Used in
28 * conjunction with lookup and remove methods.
29 *
30 * Optional method. Default behaviour is to use the ttys array
31 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070032 * int (*open)(struct tty_struct * tty, struct file * filp);
33 *
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.
Alan Coxf34d7a52008-04-30 00:54:13 -070037 *
38 * Required method.
Linus Torvalds1da177e2005-04-16 15:20:36 -070039 *
40 * void (*close)(struct tty_struct * tty, struct file * filp);
41 *
42 * This routine is called when a particular tty device is closed.
43 *
Alan Coxf34d7a52008-04-30 00:54:13 -070044 * Required method.
45 *
Alan Coxfeebed62008-10-13 10:41:30 +010046 * void (*shutdown)(struct tty_struct * tty);
47 *
48 * This routine is called when a particular tty device is closed for
49 * the last time freeing up the resources.
50 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070051 * int (*write)(struct tty_struct * tty,
52 * const unsigned char *buf, int count);
53 *
54 * This routine is called by the kernel to write a series of
55 * characters to the tty device. The characters may come from
56 * user space or kernel space. This routine will return the
Alan Cox36c73432008-06-23 12:06:52 +010057 * number of characters actually accepted for writing.
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 *
Alan Coxf34d7a52008-04-30 00:54:13 -070059 * Optional: Required for writable devices.
60 *
61 * int (*put_char)(struct tty_struct *tty, unsigned char ch);
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 *
63 * This routine is called by the kernel to write a single
64 * character to the tty device. If the kernel uses this routine,
65 * it must call the flush_chars() routine (if defined) when it is
66 * done stuffing characters into the driver. If there is no room
67 * in the queue, the character is ignored.
68 *
Alan Coxf34d7a52008-04-30 00:54:13 -070069 * Optional: Kernel will use the write method if not provided.
70 *
71 * Note: Do not call this function directly, call tty_put_char
72 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 * void (*flush_chars)(struct tty_struct *tty);
74 *
75 * This routine is called by the kernel after it has written a
76 * series of characters to the tty device using put_char().
Alan Coxf34d7a52008-04-30 00:54:13 -070077 *
78 * Optional:
79 *
80 * Note: Do not call this function directly, call tty_driver_flush_chars
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 *
82 * int (*write_room)(struct tty_struct *tty);
83 *
84 * This routine returns the numbers of characters the tty driver
85 * will accept for queuing to be written. This number is subject
86 * to change as output buffers get emptied, or if the output flow
87 * control is acted.
Alan Coxf34d7a52008-04-30 00:54:13 -070088 *
89 * Required if write method is provided else not needed.
90 *
91 * Note: Do not call this function directly, call tty_write_room
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 *
93 * int (*ioctl)(struct tty_struct *tty, struct file * file,
94 * unsigned int cmd, unsigned long arg);
95 *
96 * This routine allows the tty driver to implement
97 * device-specific ioctl's. If the ioctl number passed in cmd
98 * is not recognized by the driver, it should return ENOIOCTLCMD.
Paul Fulghume10cc1d2007-05-10 22:22:50 -070099 *
Alan Coxf34d7a52008-04-30 00:54:13 -0700100 * Optional
101 *
Paul Fulghume10cc1d2007-05-10 22:22:50 -0700102 * long (*compat_ioctl)(struct tty_struct *tty, struct file * file,
103 * unsigned int cmd, unsigned long arg);
104 *
105 * implement ioctl processing for 32 bit process on 64 bit system
Alan Coxf34d7a52008-04-30 00:54:13 -0700106 *
107 * Optional
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 *
Alan Coxedc6afc2006-12-08 02:38:44 -0800109 * void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 *
111 * This routine allows the tty driver to be notified when
Alan Coxf34d7a52008-04-30 00:54:13 -0700112 * device's termios settings have changed.
113 *
114 * Optional: Called under the termios lock
115 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 *
117 * void (*set_ldisc)(struct tty_struct *tty);
118 *
119 * This routine allows the tty driver to be notified when the
120 * device's termios settings have changed.
Alan Coxf34d7a52008-04-30 00:54:13 -0700121 *
122 * Optional: Called under BKL (currently)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 *
124 * void (*throttle)(struct tty_struct * tty);
125 *
126 * This routine notifies the tty driver that input buffers for
127 * the line discipline are close to full, and it should somehow
128 * signal that no more characters should be sent to the tty.
Alan Cox39c2e602008-04-30 00:54:18 -0700129 *
Alan Cox38db8972009-06-11 12:44:17 +0100130 * Optional: Always invoke via tty_throttle(), called under the
131 * termios lock.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 *
133 * void (*unthrottle)(struct tty_struct * tty);
134 *
135 * This routine notifies the tty drivers that it should signals
136 * that characters can now be sent to the tty without fear of
137 * overrunning the input buffers of the line disciplines.
138 *
Alan Cox38db8972009-06-11 12:44:17 +0100139 * Optional: Always invoke via tty_unthrottle(), called under the
140 * termios lock.
Alan Cox39c2e602008-04-30 00:54:18 -0700141 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 * void (*stop)(struct tty_struct *tty);
143 *
144 * This routine notifies the tty driver that it should stop
145 * outputting characters to the tty device.
Alan Coxf34d7a52008-04-30 00:54:13 -0700146 *
147 * Optional:
148 *
149 * Note: Call stop_tty not this method.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 *
151 * void (*start)(struct tty_struct *tty);
152 *
153 * This routine notifies the tty driver that it resume sending
154 * characters to the tty device.
Alan Coxf34d7a52008-04-30 00:54:13 -0700155 *
156 * Optional:
157 *
158 * Note: Call start_tty not this method.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 *
160 * void (*hangup)(struct tty_struct *tty);
161 *
162 * This routine notifies the tty driver that it should hangup the
163 * tty device.
164 *
Alan Cox36c73432008-06-23 12:06:52 +0100165 * Optional:
Alan Coxf34d7a52008-04-30 00:54:13 -0700166 *
Alan Cox9e989662008-07-22 11:18:03 +0100167 * int (*break_ctl)(struct tty_stuct *tty, int state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 *
169 * This optional routine requests the tty driver to turn on or
170 * off BREAK status on the RS-232 port. If state is -1,
171 * then the BREAK status should be turned on; if state is 0, then
172 * BREAK should be turned off.
173 *
174 * If this routine is implemented, the high-level tty driver will
175 * handle the following ioctls: TCSBRK, TCSBRKP, TIOCSBRK,
Alan Coxf34d7a52008-04-30 00:54:13 -0700176 * TIOCCBRK.
177 *
Alan Cox9e989662008-07-22 11:18:03 +0100178 * If the driver sets TTY_DRIVER_HARDWARE_BREAK then the interface
179 * will also be called with actual times and the hardware is expected
180 * to do the delay work itself. 0 and -1 are still used for on/off.
181 *
Alan Coxf34d7a52008-04-30 00:54:13 -0700182 * Optional: Required for TCSBRK/BRKP/etc handling.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 *
184 * void (*wait_until_sent)(struct tty_struct *tty, int timeout);
185 *
186 * This routine waits until the device has written out all of the
187 * characters in its transmitter FIFO.
188 *
Alan Coxf34d7a52008-04-30 00:54:13 -0700189 * Optional: If not provided the device is assumed to have no FIFO
190 *
191 * Note: Usually correct to call tty_wait_until_sent
192 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 * void (*send_xchar)(struct tty_struct *tty, char ch);
194 *
195 * This routine is used to send a high-priority XON/XOFF
196 * character to the device.
Alan Coxf34d7a52008-04-30 00:54:13 -0700197 *
198 * Optional: If not provided then the write method is called under
199 * the atomic write lock to keep it serialized with the ldisc.
Alan Cox8c9a9dd2008-08-15 10:39:38 +0100200 *
Alan Coxfc6f6232009-01-02 13:43:17 +0000201 * int (*resize)(struct tty_struct *tty, struct winsize *ws)
Alan Cox8c9a9dd2008-08-15 10:39:38 +0100202 *
203 * Called when a termios request is issued which changes the
204 * requested terminal geometry.
205 *
206 * Optional: the default action is to update the termios structure
207 * without error. This is usually the correct behaviour. Drivers should
208 * not force errors here if they are not resizable objects (eg a serial
209 * line). See tty_do_resize() if you need to wrap the standard method
210 * in your own logic - the usual case.
Alan Cox1d65b4a2008-10-13 10:38:18 +0100211 *
212 * void (*set_termiox)(struct tty_struct *tty, struct termiox *new);
213 *
214 * Called when the device receives a termiox based ioctl. Passes down
215 * the requested data from user space. This method will not be invoked
216 * unless the tty also has a valid tty->termiox pointer.
217 *
218 * Optional: Called under the termios lock
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 */
220
221#include <linux/fs.h>
222#include <linux/list.h>
223#include <linux/cdev.h>
224
225struct tty_struct;
Jason Wesself2d937f2008-04-17 20:05:37 +0200226struct tty_driver;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227
228struct tty_operations {
Sukadev Bhattiprolu15f1a632008-10-13 10:42:59 +0100229 struct tty_struct * (*lookup)(struct tty_driver *driver,
230 struct inode *inode, int idx);
Alan Cox8b0a88d2008-10-13 10:42:19 +0100231 int (*install)(struct tty_driver *driver, struct tty_struct *tty);
232 void (*remove)(struct tty_driver *driver, struct tty_struct *tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 int (*open)(struct tty_struct * tty, struct file * filp);
234 void (*close)(struct tty_struct * tty, struct file * filp);
Alan Coxfeebed62008-10-13 10:41:30 +0100235 void (*shutdown)(struct tty_struct *tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 int (*write)(struct tty_struct * tty,
237 const unsigned char *buf, int count);
Alan Coxf34d7a52008-04-30 00:54:13 -0700238 int (*put_char)(struct tty_struct *tty, unsigned char ch);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 void (*flush_chars)(struct tty_struct *tty);
240 int (*write_room)(struct tty_struct *tty);
241 int (*chars_in_buffer)(struct tty_struct *tty);
242 int (*ioctl)(struct tty_struct *tty, struct file * file,
243 unsigned int cmd, unsigned long arg);
Paul Fulghume10cc1d2007-05-10 22:22:50 -0700244 long (*compat_ioctl)(struct tty_struct *tty, struct file * file,
245 unsigned int cmd, unsigned long arg);
Alan Coxedc6afc2006-12-08 02:38:44 -0800246 void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 void (*throttle)(struct tty_struct * tty);
248 void (*unthrottle)(struct tty_struct * tty);
249 void (*stop)(struct tty_struct *tty);
250 void (*start)(struct tty_struct *tty);
251 void (*hangup)(struct tty_struct *tty);
Alan Cox9e989662008-07-22 11:18:03 +0100252 int (*break_ctl)(struct tty_struct *tty, int state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 void (*flush_buffer)(struct tty_struct *tty);
254 void (*set_ldisc)(struct tty_struct *tty);
255 void (*wait_until_sent)(struct tty_struct *tty, int timeout);
256 void (*send_xchar)(struct tty_struct *tty, char ch);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 int (*tiocmget)(struct tty_struct *tty, struct file *file);
258 int (*tiocmset)(struct tty_struct *tty, struct file *file,
259 unsigned int set, unsigned int clear);
Alan Coxfc6f6232009-01-02 13:43:17 +0000260 int (*resize)(struct tty_struct *tty, struct winsize *ws);
Alan Cox1d65b4a2008-10-13 10:38:18 +0100261 int (*set_termiox)(struct tty_struct *tty, struct termiox *tnew);
Jason Wesself2d937f2008-04-17 20:05:37 +0200262#ifdef CONFIG_CONSOLE_POLL
263 int (*poll_init)(struct tty_driver *driver, int line, char *options);
264 int (*poll_get_char)(struct tty_driver *driver, int line);
265 void (*poll_put_char)(struct tty_driver *driver, int line, char ch);
266#endif
Alexey Dobriyanae149b62009-03-31 15:19:15 -0700267 const struct file_operations *proc_fops;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268};
269
270struct tty_driver {
271 int magic; /* magic number for this structure */
Alan Cox7d7b93c2008-10-13 10:42:09 +0100272 struct kref kref; /* Reference management */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 struct cdev cdev;
274 struct module *owner;
275 const char *driver_name;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 const char *name;
277 int name_base; /* offset of printed name */
278 int major; /* major device number */
279 int minor_start; /* start of minor device number */
280 int minor_num; /* number of *possible* devices */
281 int num; /* number of devices allocated */
282 short type; /* type of tty driver */
283 short subtype; /* subtype of tty driver */
Alan Coxedc6afc2006-12-08 02:38:44 -0800284 struct ktermios init_termios; /* Initial termios */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 int flags; /* tty driver flags */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 struct proc_dir_entry *proc_entry; /* /proc fs entry */
287 struct tty_driver *other; /* only used for the PTY driver */
288
289 /*
290 * Pointer to the tty data structures
291 */
292 struct tty_struct **ttys;
Alan Coxedc6afc2006-12-08 02:38:44 -0800293 struct ktermios **termios;
294 struct ktermios **termios_locked;
Alan Coxf34d7a52008-04-30 00:54:13 -0700295 void *driver_state;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296
Alan Coxf34d7a52008-04-30 00:54:13 -0700297 /*
298 * Driver methods
299 */
300
301 const struct tty_operations *ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 struct list_head tty_drivers;
303};
304
305extern struct list_head tty_drivers;
306
Alan Cox7d7b93c2008-10-13 10:42:09 +0100307extern struct tty_driver *alloc_tty_driver(int lines);
308extern void put_tty_driver(struct tty_driver *driver);
309extern void tty_set_operations(struct tty_driver *driver,
Jeff Dikeb68e31d2006-10-02 02:17:18 -0700310 const struct tty_operations *op);
Jason Wesself2d937f2008-04-17 20:05:37 +0200311extern struct tty_driver *tty_find_polling_driver(char *name, int *line);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312
Alan Cox7d7b93c2008-10-13 10:42:09 +0100313extern void tty_driver_kref_put(struct tty_driver *driver);
Adrian Bunkf786ddd2009-04-07 16:48:07 +0100314
315static inline struct tty_driver *tty_driver_kref_get(struct tty_driver *d)
Alan Cox7d7b93c2008-10-13 10:42:09 +0100316{
317 kref_get(&d->kref);
318 return d;
319}
320
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321/* tty driver magic number */
322#define TTY_DRIVER_MAGIC 0x5402
323
324/*
325 * tty driver flags
326 *
327 * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the
328 * termios setting when the last process has closed the device.
329 * Used for PTY's, in particular.
330 *
331 * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will
332 * guarantee never not to set any special character handling
333 * flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR ||
334 * !INPCK)). That is, if there is no reason for the driver to
335 * send notifications of parity and break characters up to the
336 * line driver, it won't do so. This allows the line driver to
337 * optimize for this case if this flag is set. (Note that there
338 * is also a promise, if the above case is true, not to signal
339 * overruns, either.)
340 *
Greg Kroah-Hartman331b8312005-06-20 21:15:16 -0700341 * TTY_DRIVER_DYNAMIC_DEV --- if set, the individual tty devices need
342 * to be registered with a call to tty_register_driver() when the
343 * device is found in the system and unregistered with a call to
344 * tty_unregister_device() so the devices will be show up
345 * properly in sysfs. If not set, driver->num entries will be
346 * created by the tty core in sysfs when tty_register_driver() is
347 * called. This is to be used by drivers that have tty devices
348 * that can appear and disappear while the main tty driver is
349 * registered with the tty core.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 *
351 * TTY_DRIVER_DEVPTS_MEM -- don't use the standard arrays, instead
352 * use dynamic memory keyed through the devpts filesystem. This
353 * is only applicable to the pty driver.
Alan Cox9e989662008-07-22 11:18:03 +0100354 *
355 * TTY_DRIVER_HARDWARE_BREAK -- hardware handles break signals. Pass
356 * the requested timeout to the caller instead of using a simple
357 * on/off interface.
358 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359 */
360#define TTY_DRIVER_INSTALLED 0x0001
361#define TTY_DRIVER_RESET_TERMIOS 0x0002
362#define TTY_DRIVER_REAL_RAW 0x0004
Greg Kroah-Hartman331b8312005-06-20 21:15:16 -0700363#define TTY_DRIVER_DYNAMIC_DEV 0x0008
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364#define TTY_DRIVER_DEVPTS_MEM 0x0010
Alan Cox9e989662008-07-22 11:18:03 +0100365#define TTY_DRIVER_HARDWARE_BREAK 0x0020
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366
367/* tty driver types */
368#define TTY_DRIVER_TYPE_SYSTEM 0x0001
369#define TTY_DRIVER_TYPE_CONSOLE 0x0002
370#define TTY_DRIVER_TYPE_SERIAL 0x0003
371#define TTY_DRIVER_TYPE_PTY 0x0004
372#define TTY_DRIVER_TYPE_SCC 0x0005 /* scc driver */
373#define TTY_DRIVER_TYPE_SYSCONS 0x0006
374
375/* system subtypes (magic, used by tty_io.c) */
376#define SYSTEM_TYPE_TTY 0x0001
377#define SYSTEM_TYPE_CONSOLE 0x0002
378#define SYSTEM_TYPE_SYSCONS 0x0003
379#define SYSTEM_TYPE_SYSPTMX 0x0004
380
381/* pty subtypes (magic, used by tty_io.c) */
382#define PTY_TYPE_MASTER 0x0001
383#define PTY_TYPE_SLAVE 0x0002
384
385/* serial subtype definitions */
386#define SERIAL_TYPE_NORMAL 1
387
388#endif /* #ifdef _LINUX_TTY_DRIVER_H */