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 when a particular tty device is closed for
49 * the last time freeing up the resources.
51 * int (*write)(struct tty_struct * tty,
52 * const unsigned char *buf, int count);
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
57 * number of characters actually accepted for writing.
59 * Optional: Required for writable devices.
61 * int (*put_char)(struct tty_struct *tty, unsigned char ch);
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.
69 * Optional: Kernel will use the write method if not provided.
71 * Note: Do not call this function directly, call tty_put_char
73 * void (*flush_chars)(struct tty_struct *tty);
75 * This routine is called by the kernel after it has written a
76 * series of characters to the tty device using put_char().
80 * Note: Do not call this function directly, call tty_driver_flush_chars
82 * int (*write_room)(struct tty_struct *tty);
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
89 * Required if write method is provided else not needed.
91 * Note: Do not call this function directly, call tty_write_room
93 * int (*ioctl)(struct tty_struct *tty, struct file * file,
94 * unsigned int cmd, unsigned long arg);
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.
102 * long (*compat_ioctl)(struct tty_struct *tty, struct file * file,
103 * unsigned int cmd, unsigned long arg);
105 * implement ioctl processing for 32 bit process on 64 bit system
109 * void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
111 * This routine allows the tty driver to be notified when
112 * device's termios settings have changed.
114 * Optional: Called under the termios lock
117 * void (*set_ldisc)(struct tty_struct *tty);
119 * This routine allows the tty driver to be notified when the
120 * device's termios settings have changed.
122 * Optional: Called under BKL (currently)
124 * void (*throttle)(struct tty_struct * tty);
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.
130 * Optional: Always invoke via tty_throttle();
132 * void (*unthrottle)(struct tty_struct * tty);
134 * This routine notifies the tty drivers that it should signals
135 * that characters can now be sent to the tty without fear of
136 * overrunning the input buffers of the line disciplines.
138 * Optional: Always invoke via tty_unthrottle();
140 * void (*stop)(struct tty_struct *tty);
142 * This routine notifies the tty driver that it should stop
143 * outputting characters to the tty device.
147 * Note: Call stop_tty not this method.
149 * void (*start)(struct tty_struct *tty);
151 * This routine notifies the tty driver that it resume sending
152 * characters to the tty device.
156 * Note: Call start_tty not this method.
158 * void (*hangup)(struct tty_struct *tty);
160 * This routine notifies the tty driver that it should hangup the
165 * int (*break_ctl)(struct tty_stuct *tty, int state);
167 * This optional routine requests the tty driver to turn on or
168 * off BREAK status on the RS-232 port. If state is -1,
169 * then the BREAK status should be turned on; if state is 0, then
170 * BREAK should be turned off.
172 * If this routine is implemented, the high-level tty driver will
173 * handle the following ioctls: TCSBRK, TCSBRKP, TIOCSBRK,
176 * If the driver sets TTY_DRIVER_HARDWARE_BREAK then the interface
177 * will also be called with actual times and the hardware is expected
178 * to do the delay work itself. 0 and -1 are still used for on/off.
180 * Optional: Required for TCSBRK/BRKP/etc handling.
182 * void (*wait_until_sent)(struct tty_struct *tty, int timeout);
184 * This routine waits until the device has written out all of the
185 * characters in its transmitter FIFO.
187 * Optional: If not provided the device is assumed to have no FIFO
189 * Note: Usually correct to call tty_wait_until_sent
191 * void (*send_xchar)(struct tty_struct *tty, char ch);
193 * This routine is used to send a high-priority XON/XOFF
194 * character to the device.
196 * Optional: If not provided then the write method is called under
197 * the atomic write lock to keep it serialized with the ldisc.
199 * int (*resize)(struct tty_struct *tty, struct winsize *ws)
201 * Called when a termios request is issued which changes the
202 * requested terminal geometry.
204 * Optional: the default action is to update the termios structure
205 * without error. This is usually the correct behaviour. Drivers should
206 * not force errors here if they are not resizable objects (eg a serial
207 * line). See tty_do_resize() if you need to wrap the standard method
208 * in your own logic - the usual case.
210 * void (*set_termiox)(struct tty_struct *tty, struct termiox *new);
212 * Called when the device receives a termiox based ioctl. Passes down
213 * the requested data from user space. This method will not be invoked
214 * unless the tty also has a valid tty->termiox pointer.
216 * Optional: Called under the termios lock
219 #include <linux/fs.h>
220 #include <linux/list.h>
221 #include <linux/cdev.h>
226 struct tty_operations {
227 struct tty_struct * (*lookup)(struct tty_driver *driver,
228 struct inode *inode, int idx);
229 int (*install)(struct tty_driver *driver, struct tty_struct *tty);
230 void (*remove)(struct tty_driver *driver, struct tty_struct *tty);
231 int (*open)(struct tty_struct * tty, struct file * filp);
232 void (*close)(struct tty_struct * tty, struct file * filp);
233 void (*shutdown)(struct tty_struct *tty);
234 int (*write)(struct tty_struct * tty,
235 const unsigned char *buf, int count);
236 int (*put_char)(struct tty_struct *tty, unsigned char ch);
237 void (*flush_chars)(struct tty_struct *tty);
238 int (*write_room)(struct tty_struct *tty);
239 int (*chars_in_buffer)(struct tty_struct *tty);
240 int (*ioctl)(struct tty_struct *tty, struct file * file,
241 unsigned int cmd, unsigned long arg);
242 long (*compat_ioctl)(struct tty_struct *tty, struct file * file,
243 unsigned int cmd, unsigned long arg);
244 void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
245 void (*throttle)(struct tty_struct * tty);
246 void (*unthrottle)(struct tty_struct * tty);
247 void (*stop)(struct tty_struct *tty);
248 void (*start)(struct tty_struct *tty);
249 void (*hangup)(struct tty_struct *tty);
250 int (*break_ctl)(struct tty_struct *tty, int state);
251 void (*flush_buffer)(struct tty_struct *tty);
252 void (*set_ldisc)(struct tty_struct *tty);
253 void (*wait_until_sent)(struct tty_struct *tty, int timeout);
254 void (*send_xchar)(struct tty_struct *tty, char ch);
255 int (*tiocmget)(struct tty_struct *tty, struct file *file);
256 int (*tiocmset)(struct tty_struct *tty, struct file *file,
257 unsigned int set, unsigned int clear);
258 int (*resize)(struct tty_struct *tty, struct winsize *ws);
259 int (*set_termiox)(struct tty_struct *tty, struct termiox *tnew);
260 #ifdef CONFIG_CONSOLE_POLL
261 int (*poll_init)(struct tty_driver *driver, int line, char *options);
262 int (*poll_get_char)(struct tty_driver *driver, int line);
263 void (*poll_put_char)(struct tty_driver *driver, int line, char ch);
265 const struct file_operations *proc_fops;
269 int magic; /* magic number for this structure */
270 struct kref kref; /* Reference management */
272 struct module *owner;
273 const char *driver_name;
275 int name_base; /* offset of printed name */
276 int major; /* major device number */
277 int minor_start; /* start of minor device number */
278 int minor_num; /* number of *possible* devices */
279 int num; /* number of devices allocated */
280 short type; /* type of tty driver */
281 short subtype; /* subtype of tty driver */
282 struct ktermios init_termios; /* Initial termios */
283 int flags; /* tty driver flags */
284 struct proc_dir_entry *proc_entry; /* /proc fs entry */
285 struct tty_driver *other; /* only used for the PTY driver */
288 * Pointer to the tty data structures
290 struct tty_struct **ttys;
291 struct ktermios **termios;
292 struct ktermios **termios_locked;
299 const struct tty_operations *ops;
300 struct list_head tty_drivers;
303 extern struct list_head tty_drivers;
305 extern struct tty_driver *alloc_tty_driver(int lines);
306 extern void put_tty_driver(struct tty_driver *driver);
307 extern void tty_set_operations(struct tty_driver *driver,
308 const struct tty_operations *op);
309 extern struct tty_driver *tty_find_polling_driver(char *name, int *line);
311 extern void tty_driver_kref_put(struct tty_driver *driver);
312 extern inline struct tty_driver *tty_driver_kref_get(struct tty_driver *d)
318 /* tty driver magic number */
319 #define TTY_DRIVER_MAGIC 0x5402
324 * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the
325 * termios setting when the last process has closed the device.
326 * Used for PTY's, in particular.
328 * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will
329 * guarantee never not to set any special character handling
330 * flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR ||
331 * !INPCK)). That is, if there is no reason for the driver to
332 * send notifications of parity and break characters up to the
333 * line driver, it won't do so. This allows the line driver to
334 * optimize for this case if this flag is set. (Note that there
335 * is also a promise, if the above case is true, not to signal
338 * TTY_DRIVER_DYNAMIC_DEV --- if set, the individual tty devices need
339 * to be registered with a call to tty_register_driver() when the
340 * device is found in the system and unregistered with a call to
341 * tty_unregister_device() so the devices will be show up
342 * properly in sysfs. If not set, driver->num entries will be
343 * created by the tty core in sysfs when tty_register_driver() is
344 * called. This is to be used by drivers that have tty devices
345 * that can appear and disappear while the main tty driver is
346 * registered with the tty core.
348 * TTY_DRIVER_DEVPTS_MEM -- don't use the standard arrays, instead
349 * use dynamic memory keyed through the devpts filesystem. This
350 * is only applicable to the pty driver.
352 * TTY_DRIVER_HARDWARE_BREAK -- hardware handles break signals. Pass
353 * the requested timeout to the caller instead of using a simple
357 #define TTY_DRIVER_INSTALLED 0x0001
358 #define TTY_DRIVER_RESET_TERMIOS 0x0002
359 #define TTY_DRIVER_REAL_RAW 0x0004
360 #define TTY_DRIVER_DYNAMIC_DEV 0x0008
361 #define TTY_DRIVER_DEVPTS_MEM 0x0010
362 #define TTY_DRIVER_HARDWARE_BREAK 0x0020
364 /* tty driver types */
365 #define TTY_DRIVER_TYPE_SYSTEM 0x0001
366 #define TTY_DRIVER_TYPE_CONSOLE 0x0002
367 #define TTY_DRIVER_TYPE_SERIAL 0x0003
368 #define TTY_DRIVER_TYPE_PTY 0x0004
369 #define TTY_DRIVER_TYPE_SCC 0x0005 /* scc driver */
370 #define TTY_DRIVER_TYPE_SYSCONS 0x0006
372 /* system subtypes (magic, used by tty_io.c) */
373 #define SYSTEM_TYPE_TTY 0x0001
374 #define SYSTEM_TYPE_CONSOLE 0x0002
375 #define SYSTEM_TYPE_SYSCONS 0x0003
376 #define SYSTEM_TYPE_SYSPTMX 0x0004
378 /* pty subtypes (magic, used by tty_io.c) */
379 #define PTY_TYPE_MASTER 0x0001
380 #define PTY_TYPE_SLAVE 0x0002
382 /* serial subtype definitions */
383 #define SERIAL_TYPE_NORMAL 1
385 #endif /* #ifdef _LINUX_TTY_DRIVER_H */