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