Line data Source code
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 : *
44 : * Required method.
45 : *
46 : * void (*shutdown)(struct tty_struct * tty);
47 : *
48 : * This routine is called synchronously when a particular tty device
49 : * is closed for the last time freeing up the resources.
50 : *
51 : *
52 : * void (*cleanup)(struct tty_struct * tty);
53 : *
54 : * This routine is called asynchronously when a particular tty device
55 : * is closed for the last time freeing up the resources. This is
56 : * actually the second part of shutdown for routines that might sleep.
57 : *
58 : *
59 : * int (*write)(struct tty_struct * tty,
60 : * const unsigned char *buf, int count);
61 : *
62 : * This routine is called by the kernel to write a series of
63 : * characters to the tty device. The characters may come from
64 : * user space or kernel space. This routine will return the
65 : * number of characters actually accepted for writing.
66 : *
67 : * Optional: Required for writable devices.
68 : *
69 : * int (*put_char)(struct tty_struct *tty, unsigned char ch);
70 : *
71 : * This routine is called by the kernel to write a single
72 : * character to the tty device. If the kernel uses this routine,
73 : * it must call the flush_chars() routine (if defined) when it is
74 : * done stuffing characters into the driver. If there is no room
75 : * in the queue, the character is ignored.
76 : *
77 : * Optional: Kernel will use the write method if not provided.
78 : *
79 : * Note: Do not call this function directly, call tty_put_char
80 : *
81 : * void (*flush_chars)(struct tty_struct *tty);
82 : *
83 : * This routine is called by the kernel after it has written a
84 : * series of characters to the tty device using put_char().
85 : *
86 : * Optional:
87 : *
88 : * Note: Do not call this function directly, call tty_driver_flush_chars
89 : *
90 : * int (*write_room)(struct tty_struct *tty);
91 : *
92 : * This routine returns the numbers of characters the tty driver
93 : * will accept for queuing to be written. This number is subject
94 : * to change as output buffers get emptied, or if the output flow
95 : * control is acted.
96 : *
97 : * Required if write method is provided else not needed.
98 : *
99 : * Note: Do not call this function directly, call tty_write_room
100 : *
101 : * int (*ioctl)(struct tty_struct *tty, struct file * file,
102 : * unsigned int cmd, unsigned long arg);
103 : *
104 : * This routine allows the tty driver to implement
105 : * device-specific ioctl's. 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, struct file * file,
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 hangup the
171 : * tty device.
172 : *
173 : * Optional:
174 : *
175 : * int (*break_ctl)(struct tty_stuct *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 :
229 : #include <linux/fs.h>
230 : #include <linux/list.h>
231 : #include <linux/cdev.h>
232 :
233 : struct tty_struct;
234 : struct tty_driver;
235 :
236 : struct tty_operations {
237 : struct tty_struct * (*lookup)(struct tty_driver *driver,
238 : struct inode *inode, int idx);
239 : int (*install)(struct tty_driver *driver, struct tty_struct *tty);
240 : void (*remove)(struct tty_driver *driver, struct tty_struct *tty);
241 : int (*open)(struct tty_struct * tty, struct file * filp);
242 : void (*close)(struct tty_struct * tty, struct file * filp);
243 : void (*shutdown)(struct tty_struct *tty);
244 : void (*cleanup)(struct tty_struct *tty);
245 : int (*write)(struct tty_struct * tty,
246 : const unsigned char *buf, int count);
247 : int (*put_char)(struct tty_struct *tty, unsigned char ch);
248 : void (*flush_chars)(struct tty_struct *tty);
249 : int (*write_room)(struct tty_struct *tty);
250 : int (*chars_in_buffer)(struct tty_struct *tty);
251 : int (*ioctl)(struct tty_struct *tty, struct file * file,
252 : unsigned int cmd, unsigned long arg);
253 : long (*compat_ioctl)(struct tty_struct *tty, struct file * file,
254 : unsigned int cmd, unsigned long arg);
255 : void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
256 : void (*throttle)(struct tty_struct * tty);
257 : void (*unthrottle)(struct tty_struct * tty);
258 : void (*stop)(struct tty_struct *tty);
259 : void (*start)(struct tty_struct *tty);
260 : void (*hangup)(struct tty_struct *tty);
261 : int (*break_ctl)(struct tty_struct *tty, int state);
262 : void (*flush_buffer)(struct tty_struct *tty);
263 : void (*set_ldisc)(struct tty_struct *tty);
264 : void (*wait_until_sent)(struct tty_struct *tty, int timeout);
265 : void (*send_xchar)(struct tty_struct *tty, char ch);
266 : int (*tiocmget)(struct tty_struct *tty, struct file *file);
267 : int (*tiocmset)(struct tty_struct *tty, struct file *file,
268 : unsigned int set, unsigned int clear);
269 : int (*resize)(struct tty_struct *tty, struct winsize *ws);
270 : int (*set_termiox)(struct tty_struct *tty, struct termiox *tnew);
271 : #ifdef CONFIG_CONSOLE_POLL
272 : int (*poll_init)(struct tty_driver *driver, int line, char *options);
273 : int (*poll_get_char)(struct tty_driver *driver, int line);
274 : void (*poll_put_char)(struct tty_driver *driver, int line, char ch);
275 : #endif
276 : const struct file_operations *proc_fops;
277 : };
278 1 :
279 : struct tty_driver {
280 : int magic; /* magic number for this structure */
281 : struct kref kref; /* Reference management */
282 : struct cdev cdev;
283 : struct module *owner;
284 : const char *driver_name;
285 : const char *name;
286 : int name_base; /* offset of printed name */
287 : int major; /* major device number */
288 : int minor_start; /* start of minor device number */
289 : int minor_num; /* number of *possible* devices */
290 : int num; /* number of devices allocated */
291 : short type; /* type of tty driver */
292 : short subtype; /* subtype of tty driver */
293 : struct ktermios init_termios; /* Initial termios */
294 : int flags; /* tty driver flags */
295 : struct proc_dir_entry *proc_entry; /* /proc fs entry */
296 : struct tty_driver *other; /* only used for the PTY driver */
297 :
298 : /*
299 : * Pointer to the tty data structures
300 : */
301 : struct tty_struct **ttys;
302 : struct ktermios **termios;
303 : struct ktermios **termios_locked;
304 : void *driver_state;
305 :
306 : /*
307 : * Driver methods
308 : */
309 :
310 : const struct tty_operations *ops;
311 : struct list_head tty_drivers;
312 : };
313 :
314 : extern struct list_head tty_drivers;
315 :
316 : extern struct tty_driver *alloc_tty_driver(int lines);
317 : extern void put_tty_driver(struct tty_driver *driver);
318 : extern void tty_set_operations(struct tty_driver *driver,
319 : const struct tty_operations *op);
320 : extern struct tty_driver *tty_find_polling_driver(char *name, int *line);
321 :
322 : extern void tty_driver_kref_put(struct tty_driver *driver);
323 :
324 : static inline struct tty_driver *tty_driver_kref_get(struct tty_driver *d)
325 : {
326 : kref_get(&d->kref);
327 : return d;
328 : }
329 1 :
330 : /* tty driver magic number */
331 : #define TTY_DRIVER_MAGIC 0x5402
332 :
333 : /*
334 : * tty driver flags
335 : *
336 : * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the
337 : * termios setting when the last process has closed the device.
338 : * Used for PTY's, in particular.
339 : *
340 : * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will
341 : * guarantee never not to set any special character handling
342 : * flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR ||
343 : * !INPCK)). That is, if there is no reason for the driver to
344 : * send notifications of parity and break characters up to the
345 : * line driver, it won't do so. This allows the line driver to
346 : * optimize for this case if this flag is set. (Note that there
347 : * is also a promise, if the above case is true, not to signal
348 : * overruns, either.)
349 : *
350 : * TTY_DRIVER_DYNAMIC_DEV --- if set, the individual tty devices need
351 : * to be registered with a call to tty_register_driver() when the
352 : * device is found in the system and unregistered with a call to
353 : * tty_unregister_device() so the devices will be show up
354 : * properly in sysfs. If not set, driver->num entries will be
355 : * created by the tty core in sysfs when tty_register_driver() is
356 : * called. This is to be used by drivers that have tty devices
357 : * that can appear and disappear while the main tty driver is
358 : * registered with the tty core.
359 : *
360 : * TTY_DRIVER_DEVPTS_MEM -- don't use the standard arrays, instead
361 : * use dynamic memory keyed through the devpts filesystem. This
362 : * is only applicable to the pty driver.
363 : *
364 : * TTY_DRIVER_HARDWARE_BREAK -- hardware handles break signals. Pass
365 : * the requested timeout to the caller instead of using a simple
366 : * on/off interface.
367 : *
368 : */
369 : #define TTY_DRIVER_INSTALLED 0x0001
370 : #define TTY_DRIVER_RESET_TERMIOS 0x0002
371 : #define TTY_DRIVER_REAL_RAW 0x0004
372 : #define TTY_DRIVER_DYNAMIC_DEV 0x0008
373 : #define TTY_DRIVER_DEVPTS_MEM 0x0010
374 : #define TTY_DRIVER_HARDWARE_BREAK 0x0020
375 :
376 : /* tty driver types */
377 : #define TTY_DRIVER_TYPE_SYSTEM 0x0001
378 : #define TTY_DRIVER_TYPE_CONSOLE 0x0002
379 : #define TTY_DRIVER_TYPE_SERIAL 0x0003
380 : #define TTY_DRIVER_TYPE_PTY 0x0004
381 : #define TTY_DRIVER_TYPE_SCC 0x0005 /* scc driver */
382 : #define TTY_DRIVER_TYPE_SYSCONS 0x0006
383 :
384 : /* system subtypes (magic, used by tty_io.c) */
385 : #define SYSTEM_TYPE_TTY 0x0001
386 : #define SYSTEM_TYPE_CONSOLE 0x0002
387 : #define SYSTEM_TYPE_SYSCONS 0x0003
388 : #define SYSTEM_TYPE_SYSPTMX 0x0004
389 :
390 : /* pty subtypes (magic, used by tty_io.c) */
391 : #define PTY_TYPE_MASTER 0x0001
392 : #define PTY_TYPE_SLAVE 0x0002
393 :
394 : /* serial subtype definitions */
395 : #define SERIAL_TYPE_NORMAL 1
396 :
397 : #endif /* #ifdef _LINUX_TTY_DRIVER_H */
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