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1 : : #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 : : *
10 : : * 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 : : *
18 : : * 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 : : *
32 : : * 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.
37 : : *
38 : : * Required method.
39 : : *
40 : : * void (*close)(struct tty_struct * tty, struct file * filp);
41 : : *
42 : : * This routine is called when a particular tty device is closed.
43 : : * Note: called even if the corresponding open() failed.
44 : : *
45 : : * Required method.
46 : : *
47 : : * void (*shutdown)(struct tty_struct * tty);
48 : : *
49 : : * This routine is called under the tty lock when a particular tty device
50 : : * is closed for the last time. It executes before the tty resources
51 : : * are freed so may execute while another function holds a tty kref.
52 : : *
53 : : * void (*cleanup)(struct tty_struct * tty);
54 : : *
55 : : * This routine is called asynchronously when a particular tty device
56 : : * is closed for the last time freeing up the resources. This is
57 : : * actually the second part of shutdown for routines that might sleep.
58 : : *
59 : : *
60 : : * int (*write)(struct tty_struct * tty,
61 : : * const unsigned char *buf, int count);
62 : : *
63 : : * This routine is called by the kernel to write a series of
64 : : * characters to the tty device. The characters may come from
65 : : * user space or kernel space. This routine will return the
66 : : * number of characters actually accepted for writing.
67 : : *
68 : : * Optional: Required for writable devices.
69 : : *
70 : : * int (*put_char)(struct tty_struct *tty, unsigned char ch);
71 : : *
72 : : * This routine is called by the kernel to write a single
73 : : * character to the tty device. If the kernel uses this routine,
74 : : * it must call the flush_chars() routine (if defined) when it is
75 : : * done stuffing characters into the driver. If there is no room
76 : : * in the queue, the character is ignored.
77 : : *
78 : : * Optional: Kernel will use the write method if not provided.
79 : : *
80 : : * Note: Do not call this function directly, call tty_put_char
81 : : *
82 : : * void (*flush_chars)(struct tty_struct *tty);
83 : : *
84 : : * This routine is called by the kernel after it has written a
85 : : * series of characters to the tty device using put_char().
86 : : *
87 : : * Optional:
88 : : *
89 : : * Note: Do not call this function directly, call tty_driver_flush_chars
90 : : *
91 : : * int (*write_room)(struct tty_struct *tty);
92 : : *
93 : : * This routine returns the numbers of characters the tty driver
94 : : * will accept for queuing to be written. This number is subject
95 : : * to change as output buffers get emptied, or if the output flow
96 : : * control is acted.
97 : : *
98 : : * Required if write method is provided else not needed.
99 : : *
100 : : * Note: Do not call this function directly, call tty_write_room
101 : : *
102 : : * int (*ioctl)(struct tty_struct *tty, unsigned int cmd, unsigned long arg);
103 : : *
104 : : * This routine allows the tty driver to implement
105 : : * device-specific ioctls. If the ioctl number passed in cmd
106 : : * is not recognized by the driver, it should return ENOIOCTLCMD.
107 : : *
108 : : * Optional
109 : : *
110 : : * long (*compat_ioctl)(struct tty_struct *tty,,
111 : : * unsigned int cmd, unsigned long arg);
112 : : *
113 : : * implement ioctl processing for 32 bit process on 64 bit system
114 : : *
115 : : * Optional
116 : : *
117 : : * void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
118 : : *
119 : : * This routine allows the tty driver to be notified when
120 : : * device's termios settings have changed.
121 : : *
122 : : * Optional: Called under the termios lock
123 : : *
124 : : *
125 : : * void (*set_ldisc)(struct tty_struct *tty);
126 : : *
127 : : * This routine allows the tty driver to be notified when the
128 : : * device's termios settings have changed.
129 : : *
130 : : * Optional: Called under BKL (currently)
131 : : *
132 : : * void (*throttle)(struct tty_struct * tty);
133 : : *
134 : : * This routine notifies the tty driver that input buffers for
135 : : * the line discipline are close to full, and it should somehow
136 : : * signal that no more characters should be sent to the tty.
137 : : *
138 : : * Optional: Always invoke via tty_throttle(), called under the
139 : : * termios lock.
140 : : *
141 : : * void (*unthrottle)(struct tty_struct * tty);
142 : : *
143 : : * This routine notifies the tty drivers that it should signals
144 : : * that characters can now be sent to the tty without fear of
145 : : * overrunning the input buffers of the line disciplines.
146 : : *
147 : : * Optional: Always invoke via tty_unthrottle(), called under the
148 : : * termios lock.
149 : : *
150 : : * void (*stop)(struct tty_struct *tty);
151 : : *
152 : : * This routine notifies the tty driver that it should stop
153 : : * outputting characters to the tty device.
154 : : *
155 : : * Optional:
156 : : *
157 : : * Note: Call stop_tty not this method.
158 : : *
159 : : * void (*start)(struct tty_struct *tty);
160 : : *
161 : : * This routine notifies the tty driver that it resume sending
162 : : * characters to the tty device.
163 : : *
164 : : * Optional:
165 : : *
166 : : * Note: Call start_tty not this method.
167 : : *
168 : : * void (*hangup)(struct tty_struct *tty);
169 : : *
170 : : * This routine notifies the tty driver that it should hang up the
171 : : * tty device.
172 : : *
173 : : * Optional:
174 : : *
175 : : * int (*break_ctl)(struct tty_struct *tty, int state);
176 : : *
177 : : * This optional routine requests the tty driver to turn on or
178 : : * off BREAK status on the RS-232 port. If state is -1,
179 : : * then the BREAK status should be turned on; if state is 0, then
180 : : * BREAK should be turned off.
181 : : *
182 : : * If this routine is implemented, the high-level tty driver will
183 : : * handle the following ioctls: TCSBRK, TCSBRKP, TIOCSBRK,
184 : : * TIOCCBRK.
185 : : *
186 : : * If the driver sets TTY_DRIVER_HARDWARE_BREAK then the interface
187 : : * will also be called with actual times and the hardware is expected
188 : : * to do the delay work itself. 0 and -1 are still used for on/off.
189 : : *
190 : : * Optional: Required for TCSBRK/BRKP/etc handling.
191 : : *
192 : : * void (*wait_until_sent)(struct tty_struct *tty, int timeout);
193 : : *
194 : : * This routine waits until the device has written out all of the
195 : : * characters in its transmitter FIFO.
196 : : *
197 : : * Optional: If not provided the device is assumed to have no FIFO
198 : : *
199 : : * Note: Usually correct to call tty_wait_until_sent
200 : : *
201 : : * void (*send_xchar)(struct tty_struct *tty, char ch);
202 : : *
203 : : * This routine is used to send a high-priority XON/XOFF
204 : : * character to the device.
205 : : *
206 : : * Optional: If not provided then the write method is called under
207 : : * the atomic write lock to keep it serialized with the ldisc.
208 : : *
209 : : * int (*resize)(struct tty_struct *tty, struct winsize *ws)
210 : : *
211 : : * Called when a termios request is issued which changes the
212 : : * requested terminal geometry.
213 : : *
214 : : * Optional: the default action is to update the termios structure
215 : : * without error. This is usually the correct behaviour. Drivers should
216 : : * not force errors here if they are not resizable objects (eg a serial
217 : : * line). See tty_do_resize() if you need to wrap the standard method
218 : : * in your own logic - the usual case.
219 : : *
220 : : * void (*set_termiox)(struct tty_struct *tty, struct termiox *new);
221 : : *
222 : : * Called when the device receives a termiox based ioctl. Passes down
223 : : * the requested data from user space. This method will not be invoked
224 : : * unless the tty also has a valid tty->termiox pointer.
225 : : *
226 : : * Optional: Called under the termios lock
227 : : *
228 : : * int (*get_icount)(struct tty_struct *tty, struct serial_icounter *icount);
229 : : *
230 : : * Called when the device receives a TIOCGICOUNT ioctl. Passed a kernel
231 : : * structure to complete. This method is optional and will only be called
232 : : * if provided (otherwise EINVAL will be returned).
233 : : */
234 : :
235 : : #include <linux/export.h>
236 : : #include <linux/fs.h>
237 : : #include <linux/list.h>
238 : : #include <linux/cdev.h>
239 : : #include <linux/termios.h>
240 : :
241 : : struct tty_struct;
242 : : struct tty_driver;
243 : : struct serial_icounter_struct;
244 : :
245 : : struct tty_operations {
246 : : struct tty_struct * (*lookup)(struct tty_driver *driver,
247 : : struct inode *inode, int idx);
248 : : int (*install)(struct tty_driver *driver, struct tty_struct *tty);
249 : : void (*remove)(struct tty_driver *driver, struct tty_struct *tty);
250 : : int (*open)(struct tty_struct * tty, struct file * filp);
251 : : void (*close)(struct tty_struct * tty, struct file * filp);
252 : : void (*shutdown)(struct tty_struct *tty);
253 : : void (*cleanup)(struct tty_struct *tty);
254 : : int (*write)(struct tty_struct * tty,
255 : : const unsigned char *buf, int count);
256 : : int (*put_char)(struct tty_struct *tty, unsigned char ch);
257 : : void (*flush_chars)(struct tty_struct *tty);
258 : : int (*write_room)(struct tty_struct *tty);
259 : : int (*chars_in_buffer)(struct tty_struct *tty);
260 : : int (*ioctl)(struct tty_struct *tty,
261 : : unsigned int cmd, unsigned long arg);
262 : : long (*compat_ioctl)(struct tty_struct *tty,
263 : : unsigned int cmd, unsigned long arg);
264 : : void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
265 : : void (*throttle)(struct tty_struct * tty);
266 : : void (*unthrottle)(struct tty_struct * tty);
267 : : void (*stop)(struct tty_struct *tty);
268 : : void (*start)(struct tty_struct *tty);
269 : : void (*hangup)(struct tty_struct *tty);
270 : : int (*break_ctl)(struct tty_struct *tty, int state);
271 : : void (*flush_buffer)(struct tty_struct *tty);
272 : : void (*set_ldisc)(struct tty_struct *tty);
273 : : void (*wait_until_sent)(struct tty_struct *tty, int timeout);
274 : : void (*send_xchar)(struct tty_struct *tty, char ch);
275 : : int (*tiocmget)(struct tty_struct *tty);
276 : : int (*tiocmset)(struct tty_struct *tty,
277 : : unsigned int set, unsigned int clear);
278 : : int (*resize)(struct tty_struct *tty, struct winsize *ws);
279 : : int (*set_termiox)(struct tty_struct *tty, struct termiox *tnew);
280 : : int (*get_icount)(struct tty_struct *tty,
281 : : struct serial_icounter_struct *icount);
282 : : #ifdef CONFIG_CONSOLE_POLL
283 : : int (*poll_init)(struct tty_driver *driver, int line, char *options);
284 : : int (*poll_get_char)(struct tty_driver *driver, int line);
285 : : void (*poll_put_char)(struct tty_driver *driver, int line, char ch);
286 : : #endif
287 : : const struct file_operations *proc_fops;
288 : : };
289 : :
290 : : struct tty_driver {
291 : : int magic; /* magic number for this structure */
292 : : struct kref kref; /* Reference management */
293 : : struct cdev *cdevs;
294 : : struct module *owner;
295 : : const char *driver_name;
296 : : const char *name;
297 : : int name_base; /* offset of printed name */
298 : : int major; /* major device number */
299 : : int minor_start; /* start of minor device number */
300 : : unsigned int num; /* number of devices allocated */
301 : : short type; /* type of tty driver */
302 : : short subtype; /* subtype of tty driver */
303 : : struct ktermios init_termios; /* Initial termios */
304 : : unsigned long flags; /* tty driver flags */
305 : : struct proc_dir_entry *proc_entry; /* /proc fs entry */
306 : : struct tty_driver *other; /* only used for the PTY driver */
307 : :
308 : : /*
309 : : * Pointer to the tty data structures
310 : : */
311 : : struct tty_struct **ttys;
312 : : struct tty_port **ports;
313 : : struct ktermios **termios;
314 : : void *driver_state;
315 : :
316 : : /*
317 : : * Driver methods
318 : : */
319 : :
320 : : const struct tty_operations *ops;
321 : : struct list_head tty_drivers;
322 : : };
323 : :
324 : : extern struct list_head tty_drivers;
325 : :
326 : : extern struct tty_driver *__tty_alloc_driver(unsigned int lines,
327 : : struct module *owner, unsigned long flags);
328 : : extern void put_tty_driver(struct tty_driver *driver);
329 : : extern void tty_set_operations(struct tty_driver *driver,
330 : : const struct tty_operations *op);
331 : : extern struct tty_driver *tty_find_polling_driver(char *name, int *line);
332 : :
333 : : extern void tty_driver_kref_put(struct tty_driver *driver);
334 : :
335 : : /* Use TTY_DRIVER_* flags below */
336 : : #define tty_alloc_driver(lines, flags) \
337 : : __tty_alloc_driver(lines, THIS_MODULE, flags)
338 : :
339 : : /*
340 : : * DEPRECATED Do not use this in new code, use tty_alloc_driver instead.
341 : : * (And change the return value checks.)
342 : : */
343 : : static inline struct tty_driver *alloc_tty_driver(unsigned int lines)
344 : : {
345 : 0 : struct tty_driver *ret = tty_alloc_driver(lines, 0);
346 [ # # ]: 0 : if (IS_ERR(ret))
347 : : return NULL;
348 : : return ret;
349 : : }
350 : :
351 : : static inline struct tty_driver *tty_driver_kref_get(struct tty_driver *d)
352 : : {
353 : : kref_get(&d->kref);
354 : : return d;
355 : : }
356 : :
357 : : /* tty driver magic number */
358 : : #define TTY_DRIVER_MAGIC 0x5402
359 : :
360 : : /*
361 : : * tty driver flags
362 : : *
363 : : * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the
364 : : * termios setting when the last process has closed the device.
365 : : * Used for PTY's, in particular.
366 : : *
367 : : * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will
368 : : * guarantee never not to set any special character handling
369 : : * flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR ||
370 : : * !INPCK)). That is, if there is no reason for the driver to
371 : : * send notifications of parity and break characters up to the
372 : : * line driver, it won't do so. This allows the line driver to
373 : : * optimize for this case if this flag is set. (Note that there
374 : : * is also a promise, if the above case is true, not to signal
375 : : * overruns, either.)
376 : : *
377 : : * TTY_DRIVER_DYNAMIC_DEV --- if set, the individual tty devices need
378 : : * to be registered with a call to tty_register_device() when the
379 : : * device is found in the system and unregistered with a call to
380 : : * tty_unregister_device() so the devices will be show up
381 : : * properly in sysfs. If not set, driver->num entries will be
382 : : * created by the tty core in sysfs when tty_register_driver() is
383 : : * called. This is to be used by drivers that have tty devices
384 : : * that can appear and disappear while the main tty driver is
385 : : * registered with the tty core.
386 : : *
387 : : * TTY_DRIVER_DEVPTS_MEM -- don't use the standard arrays, instead
388 : : * use dynamic memory keyed through the devpts filesystem. This
389 : : * is only applicable to the pty driver.
390 : : *
391 : : * TTY_DRIVER_HARDWARE_BREAK -- hardware handles break signals. Pass
392 : : * the requested timeout to the caller instead of using a simple
393 : : * on/off interface.
394 : : *
395 : : * TTY_DRIVER_DYNAMIC_ALLOC -- do not allocate structures which are
396 : : * needed per line for this driver as it would waste memory.
397 : : * The driver will take care.
398 : : *
399 : : * TTY_DRIVER_UNNUMBERED_NODE -- do not create numbered /dev nodes. In
400 : : * other words create /dev/ttyprintk and not /dev/ttyprintk0.
401 : : * Applicable only when a driver for a single tty device is
402 : : * being allocated.
403 : : */
404 : : #define TTY_DRIVER_INSTALLED 0x0001
405 : : #define TTY_DRIVER_RESET_TERMIOS 0x0002
406 : : #define TTY_DRIVER_REAL_RAW 0x0004
407 : : #define TTY_DRIVER_DYNAMIC_DEV 0x0008
408 : : #define TTY_DRIVER_DEVPTS_MEM 0x0010
409 : : #define TTY_DRIVER_HARDWARE_BREAK 0x0020
410 : : #define TTY_DRIVER_DYNAMIC_ALLOC 0x0040
411 : : #define TTY_DRIVER_UNNUMBERED_NODE 0x0080
412 : :
413 : : /* tty driver types */
414 : : #define TTY_DRIVER_TYPE_SYSTEM 0x0001
415 : : #define TTY_DRIVER_TYPE_CONSOLE 0x0002
416 : : #define TTY_DRIVER_TYPE_SERIAL 0x0003
417 : : #define TTY_DRIVER_TYPE_PTY 0x0004
418 : : #define TTY_DRIVER_TYPE_SCC 0x0005 /* scc driver */
419 : : #define TTY_DRIVER_TYPE_SYSCONS 0x0006
420 : :
421 : : /* system subtypes (magic, used by tty_io.c) */
422 : : #define SYSTEM_TYPE_TTY 0x0001
423 : : #define SYSTEM_TYPE_CONSOLE 0x0002
424 : : #define SYSTEM_TYPE_SYSCONS 0x0003
425 : : #define SYSTEM_TYPE_SYSPTMX 0x0004
426 : :
427 : : /* pty subtypes (magic, used by tty_io.c) */
428 : : #define PTY_TYPE_MASTER 0x0001
429 : : #define PTY_TYPE_SLAVE 0x0002
430 : :
431 : : /* serial subtype definitions */
432 : : #define SERIAL_TYPE_NORMAL 1
433 : :
434 : : #endif /* #ifdef _LINUX_TTY_DRIVER_H */
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