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linux
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 * int (*open)(struct tty_struct * tty, struct file * filp);
11 *
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.
15 *
16 * Required method.
17 *
18 * void (*close)(struct tty_struct * tty, struct file * filp);
19 *
20 * This routine is called when a particular tty device is closed.
21 *
22 * Required method.
23 *
24 * int (*write)(struct tty_struct * tty,
25 * const unsigned char *buf, int count);
26 *
27 * This routine is called by the kernel to write a series of
28 * characters to the tty device. The characters may come from
29 * user space or kernel space. This routine will return the
30 * number of characters actually accepted for writing.
31 *
32 * Optional: Required for writable devices.
33 *
34 * int (*put_char)(struct tty_struct *tty, unsigned char ch);
35 *
36 * This routine is called by the kernel to write a single
37 * character to the tty device. If the kernel uses this routine,
38 * it must call the flush_chars() routine (if defined) when it is
39 * done stuffing characters into the driver. If there is no room
40 * in the queue, the character is ignored.
41 *
42 * Optional: Kernel will use the write method if not provided.
43 *
44 * Note: Do not call this function directly, call tty_put_char
45 *
46 * void (*flush_chars)(struct tty_struct *tty);
47 *
48 * This routine is called by the kernel after it has written a
49 * series of characters to the tty device using put_char().
50 *
51 * Optional:
52 *
53 * Note: Do not call this function directly, call tty_driver_flush_chars
54 *
55 * int (*write_room)(struct tty_struct *tty);
56 *
57 * This routine returns the numbers of characters the tty driver
58 * will accept for queuing to be written. This number is subject
59 * to change as output buffers get emptied, or if the output flow
60 * control is acted.
61 *
62 * Required if write method is provided else not needed.
63 *
64 * Note: Do not call this function directly, call tty_write_room
65 *
66 * int (*ioctl)(struct tty_struct *tty, struct file * file,
67 * unsigned int cmd, unsigned long arg);
68 *
69 * This routine allows the tty driver to implement
70 * device-specific ioctl's. If the ioctl number passed in cmd
71 * is not recognized by the driver, it should return ENOIOCTLCMD.
72 *
73 * Optional
74 *
75 * long (*compat_ioctl)(struct tty_struct *tty, struct file * file,
76 * unsigned int cmd, unsigned long arg);
77 *
78 * implement ioctl processing for 32 bit process on 64 bit system
79 *
80 * Optional
81 *
82 * void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
83 *
84 * This routine allows the tty driver to be notified when
85 * device's termios settings have changed.
86 *
87 * Optional: Called under the termios lock
88 *
89 *
90 * void (*set_ldisc)(struct tty_struct *tty);
91 *
92 * This routine allows the tty driver to be notified when the
93 * device's termios settings have changed.
94 *
95 * Optional: Called under BKL (currently)
96 *
97 * void (*throttle)(struct tty_struct * tty);
98 *
99 * This routine notifies the tty driver that input buffers for
100 * the line discipline are close to full, and it should somehow
101 * signal that no more characters should be sent to the tty.
102 *
103 * Optional: Always invoke via tty_throttle();
104 *
105 * void (*unthrottle)(struct tty_struct * tty);
106 *
107 * This routine notifies the tty drivers that it should signals
108 * that characters can now be sent to the tty without fear of
109 * overrunning the input buffers of the line disciplines.
110 *
111 * Optional: Always invoke via tty_unthrottle();
112 *
113 * void (*stop)(struct tty_struct *tty);
114 *
115 * This routine notifies the tty driver that it should stop
116 * outputting characters to the tty device.
117 *
118 * Optional:
119 *
120 * Note: Call stop_tty not this method.
121 *
122 * void (*start)(struct tty_struct *tty);
123 *
124 * This routine notifies the tty driver that it resume sending
125 * characters to the tty device.
126 *
127 * Optional:
128 *
129 * Note: Call start_tty not this method.
130 *
131 * void (*hangup)(struct tty_struct *tty);
132 *
133 * This routine notifies the tty driver that it should hangup the
134 * tty device.
135 *
136 * Optional:
137 *
138 * void (*break_ctl)(struct tty_stuct *tty, int state);
139 *
140 * This optional routine requests the tty driver to turn on or
141 * off BREAK status on the RS-232 port. If state is -1,
142 * then the BREAK status should be turned on; if state is 0, then
143 * BREAK should be turned off.
144 *
145 * If this routine is implemented, the high-level tty driver will
146 * handle the following ioctls: TCSBRK, TCSBRKP, TIOCSBRK,
147 * TIOCCBRK.
148 *
149 * Optional: Required for TCSBRK/BRKP/etc handling.
150 *
151 * void (*wait_until_sent)(struct tty_struct *tty, int timeout);
152 *
153 * This routine waits until the device has written out all of the
154 * characters in its transmitter FIFO.
155 *
156 * Optional: If not provided the device is assumed to have no FIFO
157 *
158 * Note: Usually correct to call tty_wait_until_sent
159 *
160 * void (*send_xchar)(struct tty_struct *tty, char ch);
161 *
162 * This routine is used to send a high-priority XON/XOFF
163 * character to the device.
164 *
165 * Optional: If not provided then the write method is called under
166 * the atomic write lock to keep it serialized with the ldisc.
167 */
168
169#include <linux/fs.h>
170#include <linux/list.h>
171#include <linux/cdev.h>
172
173struct tty_struct;
174struct tty_driver;
175
176struct tty_operations {
177 int (*open)(struct tty_struct * tty, struct file * filp);
178 void (*close)(struct tty_struct * tty, struct file * filp);
179 int (*write)(struct tty_struct * tty,
180 const unsigned char *buf, int count);
181 int (*put_char)(struct tty_struct *tty, unsigned char ch);
182 void (*flush_chars)(struct tty_struct *tty);
183 int (*write_room)(struct tty_struct *tty);
184 int (*chars_in_buffer)(struct tty_struct *tty);
185 int (*ioctl)(struct tty_struct *tty, struct file * file,
186 unsigned int cmd, unsigned long arg);
187 long (*compat_ioctl)(struct tty_struct *tty, struct file * file,
188 unsigned int cmd, unsigned long arg);
189 void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
190 void (*throttle)(struct tty_struct * tty);
191 void (*unthrottle)(struct tty_struct * tty);
192 void (*stop)(struct tty_struct *tty);
193 void (*start)(struct tty_struct *tty);
194 void (*hangup)(struct tty_struct *tty);
195 void (*break_ctl)(struct tty_struct *tty, int state);
196 void (*flush_buffer)(struct tty_struct *tty);
197 void (*set_ldisc)(struct tty_struct *tty);
198 void (*wait_until_sent)(struct tty_struct *tty, int timeout);
199 void (*send_xchar)(struct tty_struct *tty, char ch);
200 int (*read_proc)(char *page, char **start, off_t off,
201 int count, int *eof, void *data);
202 int (*tiocmget)(struct tty_struct *tty, struct file *file);
203 int (*tiocmset)(struct tty_struct *tty, struct file *file,
204 unsigned int set, unsigned int clear);
205#ifdef CONFIG_CONSOLE_POLL
206 int (*poll_init)(struct tty_driver *driver, int line, char *options);
207 int (*poll_get_char)(struct tty_driver *driver, int line);
208 void (*poll_put_char)(struct tty_driver *driver, int line, char ch);
209#endif
210};
211
212struct tty_driver {
213 int magic; /* magic number for this structure */
214 struct cdev cdev;
215 struct module *owner;
216 const char *driver_name;
217 const char *name;
218 int name_base; /* offset of printed name */
219 int major; /* major device number */
220 int minor_start; /* start of minor device number */
221 int minor_num; /* number of *possible* devices */
222 int num; /* number of devices allocated */
223 short type; /* type of tty driver */
224 short subtype; /* subtype of tty driver */
225 struct ktermios init_termios; /* Initial termios */
226 int flags; /* tty driver flags */
227 int refcount; /* for loadable tty drivers */
228 struct proc_dir_entry *proc_entry; /* /proc fs entry */
229 struct tty_driver *other; /* only used for the PTY driver */
230
231 /*
232 * Pointer to the tty data structures
233 */
234 struct tty_struct **ttys;
235 struct ktermios **termios;
236 struct ktermios **termios_locked;
237 void *driver_state;
238
239 /*
240 * Driver methods
241 */
242
243 const struct tty_operations *ops;
244 struct list_head tty_drivers;
245};
246
247extern struct list_head tty_drivers;
248
249struct tty_driver *alloc_tty_driver(int lines);
250void put_tty_driver(struct tty_driver *driver);
251void tty_set_operations(struct tty_driver *driver,
252 const struct tty_operations *op);
253extern struct tty_driver *tty_find_polling_driver(char *name, int *line);
254
255/* tty driver magic number */
256#define TTY_DRIVER_MAGIC 0x5402
257
258/*
259 * tty driver flags
260 *
261 * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the
262 * termios setting when the last process has closed the device.
263 * Used for PTY's, in particular.
264 *
265 * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will
266 * guarantee never not to set any special character handling
267 * flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR ||
268 * !INPCK)). That is, if there is no reason for the driver to
269 * send notifications of parity and break characters up to the
270 * line driver, it won't do so. This allows the line driver to
271 * optimize for this case if this flag is set. (Note that there
272 * is also a promise, if the above case is true, not to signal
273 * overruns, either.)
274 *
275 * TTY_DRIVER_DYNAMIC_DEV --- if set, the individual tty devices need
276 * to be registered with a call to tty_register_driver() when the
277 * device is found in the system and unregistered with a call to
278 * tty_unregister_device() so the devices will be show up
279 * properly in sysfs. If not set, driver->num entries will be
280 * created by the tty core in sysfs when tty_register_driver() is
281 * called. This is to be used by drivers that have tty devices
282 * that can appear and disappear while the main tty driver is
283 * registered with the tty core.
284 *
285 * TTY_DRIVER_DEVPTS_MEM -- don't use the standard arrays, instead
286 * use dynamic memory keyed through the devpts filesystem. This
287 * is only applicable to the pty driver.
288 */
289#define TTY_DRIVER_INSTALLED 0x0001
290#define TTY_DRIVER_RESET_TERMIOS 0x0002
291#define TTY_DRIVER_REAL_RAW 0x0004
292#define TTY_DRIVER_DYNAMIC_DEV 0x0008
293#define TTY_DRIVER_DEVPTS_MEM 0x0010
294
295/* tty driver types */
296#define TTY_DRIVER_TYPE_SYSTEM 0x0001
297#define TTY_DRIVER_TYPE_CONSOLE 0x0002
298#define TTY_DRIVER_TYPE_SERIAL 0x0003
299#define TTY_DRIVER_TYPE_PTY 0x0004
300#define TTY_DRIVER_TYPE_SCC 0x0005 /* scc driver */
301#define TTY_DRIVER_TYPE_SYSCONS 0x0006
302
303/* system subtypes (magic, used by tty_io.c) */
304#define SYSTEM_TYPE_TTY 0x0001
305#define SYSTEM_TYPE_CONSOLE 0x0002
306#define SYSTEM_TYPE_SYSCONS 0x0003
307#define SYSTEM_TYPE_SYSPTMX 0x0004
308
309/* pty subtypes (magic, used by tty_io.c) */
310#define PTY_TYPE_MASTER 0x0001
311#define PTY_TYPE_SLAVE 0x0002
312
313/* serial subtype definitions */
314#define SERIAL_TYPE_NORMAL 1
315
316#endif /* #ifdef _LINUX_TTY_DRIVER_H */