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 * int (*open)(struct tty_struct * tty, struct file * filp);
12 * This routine is called when a particular tty device is opened.
13 * This routine is mandatory; if this routine is not filled in,
14 * the attempted open will fail with ENODEV.
18 * void (*close)(struct tty_struct * tty, struct file * filp);
20 * This routine is called when a particular tty device is closed.
24 * void (*shutdown)(struct tty_struct * tty);
26 * This routine is called when a particular tty device is closed for
27 * the last time freeing up the resources.
29 * int (*write)(struct tty_struct * tty,
30 * const unsigned char *buf, int count);
32 * This routine is called by the kernel to write a series of
33 * characters to the tty device. The characters may come from
34 * user space or kernel space. This routine will return the
35 * number of characters actually accepted for writing.
37 * Optional: Required for writable devices.
39 * int (*put_char)(struct tty_struct *tty, unsigned char ch);
41 * This routine is called by the kernel to write a single
42 * character to the tty device. If the kernel uses this routine,
43 * it must call the flush_chars() routine (if defined) when it is
44 * done stuffing characters into the driver. If there is no room
45 * in the queue, the character is ignored.
47 * Optional: Kernel will use the write method if not provided.
49 * Note: Do not call this function directly, call tty_put_char
51 * void (*flush_chars)(struct tty_struct *tty);
53 * This routine is called by the kernel after it has written a
54 * series of characters to the tty device using put_char().
58 * Note: Do not call this function directly, call tty_driver_flush_chars
60 * int (*write_room)(struct tty_struct *tty);
62 * This routine returns the numbers of characters the tty driver
63 * will accept for queuing to be written. This number is subject
64 * to change as output buffers get emptied, or if the output flow
67 * Required if write method is provided else not needed.
69 * Note: Do not call this function directly, call tty_write_room
71 * int (*ioctl)(struct tty_struct *tty, struct file * file,
72 * unsigned int cmd, unsigned long arg);
74 * This routine allows the tty driver to implement
75 * device-specific ioctl's. If the ioctl number passed in cmd
76 * is not recognized by the driver, it should return ENOIOCTLCMD.
80 * long (*compat_ioctl)(struct tty_struct *tty, struct file * file,
81 * unsigned int cmd, unsigned long arg);
83 * implement ioctl processing for 32 bit process on 64 bit system
87 * void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
89 * This routine allows the tty driver to be notified when
90 * device's termios settings have changed.
92 * Optional: Called under the termios lock
95 * void (*set_ldisc)(struct tty_struct *tty);
97 * This routine allows the tty driver to be notified when the
98 * device's termios settings have changed.
100 * Optional: Called under BKL (currently)
102 * void (*throttle)(struct tty_struct * tty);
104 * This routine notifies the tty driver that input buffers for
105 * the line discipline are close to full, and it should somehow
106 * signal that no more characters should be sent to the tty.
108 * Optional: Always invoke via tty_throttle();
110 * void (*unthrottle)(struct tty_struct * tty);
112 * This routine notifies the tty drivers that it should signals
113 * that characters can now be sent to the tty without fear of
114 * overrunning the input buffers of the line disciplines.
116 * Optional: Always invoke via tty_unthrottle();
118 * void (*stop)(struct tty_struct *tty);
120 * This routine notifies the tty driver that it should stop
121 * outputting characters to the tty device.
125 * Note: Call stop_tty not this method.
127 * void (*start)(struct tty_struct *tty);
129 * This routine notifies the tty driver that it resume sending
130 * characters to the tty device.
134 * Note: Call start_tty not this method.
136 * void (*hangup)(struct tty_struct *tty);
138 * This routine notifies the tty driver that it should hangup the
143 * int (*break_ctl)(struct tty_stuct *tty, int state);
145 * This optional routine requests the tty driver to turn on or
146 * off BREAK status on the RS-232 port. If state is -1,
147 * then the BREAK status should be turned on; if state is 0, then
148 * BREAK should be turned off.
150 * If this routine is implemented, the high-level tty driver will
151 * handle the following ioctls: TCSBRK, TCSBRKP, TIOCSBRK,
154 * If the driver sets TTY_DRIVER_HARDWARE_BREAK then the interface
155 * will also be called with actual times and the hardware is expected
156 * to do the delay work itself. 0 and -1 are still used for on/off.
158 * Optional: Required for TCSBRK/BRKP/etc handling.
160 * void (*wait_until_sent)(struct tty_struct *tty, int timeout);
162 * This routine waits until the device has written out all of the
163 * characters in its transmitter FIFO.
165 * Optional: If not provided the device is assumed to have no FIFO
167 * Note: Usually correct to call tty_wait_until_sent
169 * void (*send_xchar)(struct tty_struct *tty, char ch);
171 * This routine is used to send a high-priority XON/XOFF
172 * character to the device.
174 * Optional: If not provided then the write method is called under
175 * the atomic write lock to keep it serialized with the ldisc.
177 * int (*resize)(struct tty_struct *tty, struct tty_struct *real_tty,
178 * unsigned int rows, unsigned int cols);
180 * Called when a termios request is issued which changes the
181 * requested terminal geometry.
183 * Optional: the default action is to update the termios structure
184 * without error. This is usually the correct behaviour. Drivers should
185 * not force errors here if they are not resizable objects (eg a serial
186 * line). See tty_do_resize() if you need to wrap the standard method
187 * in your own logic - the usual case.
189 * void (*set_termiox)(struct tty_struct *tty, struct termiox *new);
191 * Called when the device receives a termiox based ioctl. Passes down
192 * the requested data from user space. This method will not be invoked
193 * unless the tty also has a valid tty->termiox pointer.
195 * Optional: Called under the termios lock
198 #include <linux/fs.h>
199 #include <linux/list.h>
200 #include <linux/cdev.h>
205 struct tty_operations {
206 int (*open)(struct tty_struct * tty, struct file * filp);
207 void (*close)(struct tty_struct * tty, struct file * filp);
208 void (*shutdown)(struct tty_struct *tty);
209 int (*write)(struct tty_struct * tty,
210 const unsigned char *buf, int count);
211 int (*put_char)(struct tty_struct *tty, unsigned char ch);
212 void (*flush_chars)(struct tty_struct *tty);
213 int (*write_room)(struct tty_struct *tty);
214 int (*chars_in_buffer)(struct tty_struct *tty);
215 int (*ioctl)(struct tty_struct *tty, struct file * file,
216 unsigned int cmd, unsigned long arg);
217 long (*compat_ioctl)(struct tty_struct *tty, struct file * file,
218 unsigned int cmd, unsigned long arg);
219 void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
220 void (*throttle)(struct tty_struct * tty);
221 void (*unthrottle)(struct tty_struct * tty);
222 void (*stop)(struct tty_struct *tty);
223 void (*start)(struct tty_struct *tty);
224 void (*hangup)(struct tty_struct *tty);
225 int (*break_ctl)(struct tty_struct *tty, int state);
226 void (*flush_buffer)(struct tty_struct *tty);
227 void (*set_ldisc)(struct tty_struct *tty);
228 void (*wait_until_sent)(struct tty_struct *tty, int timeout);
229 void (*send_xchar)(struct tty_struct *tty, char ch);
230 int (*read_proc)(char *page, char **start, off_t off,
231 int count, int *eof, void *data);
232 int (*tiocmget)(struct tty_struct *tty, struct file *file);
233 int (*tiocmset)(struct tty_struct *tty, struct file *file,
234 unsigned int set, unsigned int clear);
235 int (*resize)(struct tty_struct *tty, struct tty_struct *real_tty,
237 int (*set_termiox)(struct tty_struct *tty, struct termiox *tnew);
238 #ifdef CONFIG_CONSOLE_POLL
239 int (*poll_init)(struct tty_driver *driver, int line, char *options);
240 int (*poll_get_char)(struct tty_driver *driver, int line);
241 void (*poll_put_char)(struct tty_driver *driver, int line, char ch);
246 int magic; /* magic number for this structure */
248 struct module *owner;
249 const char *driver_name;
251 int name_base; /* offset of printed name */
252 int major; /* major device number */
253 int minor_start; /* start of minor device number */
254 int minor_num; /* number of *possible* devices */
255 int num; /* number of devices allocated */
256 short type; /* type of tty driver */
257 short subtype; /* subtype of tty driver */
258 struct ktermios init_termios; /* Initial termios */
259 int flags; /* tty driver flags */
260 int refcount; /* for loadable tty drivers */
261 struct proc_dir_entry *proc_entry; /* /proc fs entry */
262 struct tty_driver *other; /* only used for the PTY driver */
265 * Pointer to the tty data structures
267 struct tty_struct **ttys;
268 struct ktermios **termios;
269 struct ktermios **termios_locked;
276 const struct tty_operations *ops;
277 struct list_head tty_drivers;
280 extern struct list_head tty_drivers;
282 struct tty_driver *alloc_tty_driver(int lines);
283 void put_tty_driver(struct tty_driver *driver);
284 void tty_set_operations(struct tty_driver *driver,
285 const struct tty_operations *op);
286 extern struct tty_driver *tty_find_polling_driver(char *name, int *line);
288 /* tty driver magic number */
289 #define TTY_DRIVER_MAGIC 0x5402
294 * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the
295 * termios setting when the last process has closed the device.
296 * Used for PTY's, in particular.
298 * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will
299 * guarantee never not to set any special character handling
300 * flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR ||
301 * !INPCK)). That is, if there is no reason for the driver to
302 * send notifications of parity and break characters up to the
303 * line driver, it won't do so. This allows the line driver to
304 * optimize for this case if this flag is set. (Note that there
305 * is also a promise, if the above case is true, not to signal
308 * TTY_DRIVER_DYNAMIC_DEV --- if set, the individual tty devices need
309 * to be registered with a call to tty_register_driver() when the
310 * device is found in the system and unregistered with a call to
311 * tty_unregister_device() so the devices will be show up
312 * properly in sysfs. If not set, driver->num entries will be
313 * created by the tty core in sysfs when tty_register_driver() is
314 * called. This is to be used by drivers that have tty devices
315 * that can appear and disappear while the main tty driver is
316 * registered with the tty core.
318 * TTY_DRIVER_DEVPTS_MEM -- don't use the standard arrays, instead
319 * use dynamic memory keyed through the devpts filesystem. This
320 * is only applicable to the pty driver.
322 * TTY_DRIVER_HARDWARE_BREAK -- hardware handles break signals. Pass
323 * the requested timeout to the caller instead of using a simple
327 #define TTY_DRIVER_INSTALLED 0x0001
328 #define TTY_DRIVER_RESET_TERMIOS 0x0002
329 #define TTY_DRIVER_REAL_RAW 0x0004
330 #define TTY_DRIVER_DYNAMIC_DEV 0x0008
331 #define TTY_DRIVER_DEVPTS_MEM 0x0010
332 #define TTY_DRIVER_HARDWARE_BREAK 0x0020
334 /* tty driver types */
335 #define TTY_DRIVER_TYPE_SYSTEM 0x0001
336 #define TTY_DRIVER_TYPE_CONSOLE 0x0002
337 #define TTY_DRIVER_TYPE_SERIAL 0x0003
338 #define TTY_DRIVER_TYPE_PTY 0x0004
339 #define TTY_DRIVER_TYPE_SCC 0x0005 /* scc driver */
340 #define TTY_DRIVER_TYPE_SYSCONS 0x0006
342 /* system subtypes (magic, used by tty_io.c) */
343 #define SYSTEM_TYPE_TTY 0x0001
344 #define SYSTEM_TYPE_CONSOLE 0x0002
345 #define SYSTEM_TYPE_SYSCONS 0x0003
346 #define SYSTEM_TYPE_SYSPTMX 0x0004
348 /* pty subtypes (magic, used by tty_io.c) */
349 #define PTY_TYPE_MASTER 0x0001
350 #define PTY_TYPE_SLAVE 0x0002
352 /* serial subtype definitions */
353 #define SERIAL_TYPE_NORMAL 1
355 #endif /* #ifdef _LINUX_TTY_DRIVER_H */