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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 * void (*close)(struct tty_struct * tty, struct file * filp);
17 *
18 * This routine is called when a particular tty device is closed.
19 *
20 * int (*write)(struct tty_struct * tty, int from_user,
21 * unsigned char *buf, int count);
22 *
23 * This routine is called by the kernel to write a series of
24 * characters to the tty device. The characters may come from
25 * user space or kernel space. This routine will return the
26 * number of characters actually accepted for writing. This
27 * routine is mandatory.
28 *
29 * void (*put_char)(struct tty_struct *tty, unsigned char ch);
30 *
31 * This routine is called by the kernel to write a single
32 * character to the tty device. If the kernel uses this routine,
33 * it must call the flush_chars() routine (if defined) when it is
34 * done stuffing characters into the driver. If there is no room
35 * in the queue, the character is ignored.
36 *
37 * void (*flush_chars)(struct tty_struct *tty);
38 *
39 * This routine is called by the kernel after it has written a
40 * series of characters to the tty device using put_char().
41 *
42 * int (*write_room)(struct tty_struct *tty);
43 *
44 * This routine returns the numbers of characters the tty driver
45 * will accept for queuing to be written. This number is subject
46 * to change as output buffers get emptied, or if the output flow
47 * control is acted.
48 *
49 * int (*ioctl)(struct tty_struct *tty, struct file * file,
50 * unsigned int cmd, unsigned long arg);
51 *
52 * This routine allows the tty driver to implement
53 * device-specific ioctl's. If the ioctl number passed in cmd
54 * is not recognized by the driver, it should return ENOIOCTLCMD.
55 *
56 * void (*set_termios)(struct tty_struct *tty, struct termios * old);
57 *
58 * This routine allows the tty driver to be notified when
59 * device's termios settings have changed. Note that a
60 * well-designed tty driver should be prepared to accept the case
61 * where old == NULL, and try to do something rational.
62 *
63 * void (*set_ldisc)(struct tty_struct *tty);
64 *
65 * This routine allows the tty driver to be notified when the
66 * device's termios settings have changed.
67 *
68 * void (*throttle)(struct tty_struct * tty);
69 *
70 * This routine notifies the tty driver that input buffers for
71 * the line discipline are close to full, and it should somehow
72 * signal that no more characters should be sent to the tty.
73 *
74 * void (*unthrottle)(struct tty_struct * tty);
75 *
76 * This routine notifies the tty drivers that it should signals
77 * that characters can now be sent to the tty without fear of
78 * overrunning the input buffers of the line disciplines.
79 *
80 * void (*stop)(struct tty_struct *tty);
81 *
82 * This routine notifies the tty driver that it should stop
83 * outputting characters to the tty device.
84 *
85 * void (*start)(struct tty_struct *tty);
86 *
87 * This routine notifies the tty driver that it resume sending
88 * characters to the tty device.
89 *
90 * void (*hangup)(struct tty_struct *tty);
91 *
92 * This routine notifies the tty driver that it should hangup the
93 * tty device.
94 *
95 */
96
97 #include <linux/fs.h>
98
99 struct tty_driver {
100 int magic; /* magic number for this structure */
101 char *name;
102 int name_base; /* offset of printed name */
103 short major; /* major device number */
104 short minor_start; /* start of minor device number*/
105 short num; /* number of devices */
106 short type; /* type of tty driver */
107 short subtype; /* subtype of tty driver */
108 struct termios init_termios; /* Initial termios */
109 int flags; /* tty driver flags */
110 int *refcount; /* for loadable tty drivers */
111 struct tty_driver *other; /* only used for the PTY driver */
112
113 /*
114 * Pointer to the tty data structures
115 */
116 struct tty_struct **table;
117 struct termios **termios;
118 struct termios **termios_locked;
119
120 /*
121 * Interface routines from the upper tty layer to the tty
122 * driver.
123 */
124 int (*open)(struct tty_struct * tty, struct file * filp);
125 void (*close)(struct tty_struct * tty, struct file * filp);
126 int (*write)(struct tty_struct * tty, int from_user,
127 unsigned char *buf, int count);
128 void (*put_char)(struct tty_struct *tty, unsigned char ch);
129 void (*flush_chars)(struct tty_struct *tty);
130 int (*write_room)(struct tty_struct *tty);
131 int (*chars_in_buffer)(struct tty_struct *tty);
132 int (*ioctl)(struct tty_struct *tty, struct file * file,
133 unsigned int cmd, unsigned long arg);
134 void (*set_termios)(struct tty_struct *tty, struct termios * old);
135 void (*throttle)(struct tty_struct * tty);
136 void (*unthrottle)(struct tty_struct * tty);
137 void (*stop)(struct tty_struct *tty);
138 void (*start)(struct tty_struct *tty);
139 void (*hangup)(struct tty_struct *tty);
140 void (*flush_buffer)(struct tty_struct *tty);
141 void (*set_ldisc)(struct tty_struct *tty);
142
143 /*
144 * linked list pointers
145 */
146 struct tty_driver *next;
147 struct tty_driver *prev;
148 };
149
150 /* tty driver magic number */
151 #define TTY_DRIVER_MAGIC 0x5402
152
153 /*
154 * tty driver flags
155 *
156 * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the
157 * termios setting when the last process has closed the device.
158 * Used for PTY's, in particular.
159 *
160 * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will
161 * guarantee never not to set any special character handling
162 * flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR ||
163 * !INPCK)). That is, if there is no reason for the driver to
164 * send notifications of parity and break characters up to the
165 * line driver, it won't do so. This allows the line driver to
166 * optimize for this case if this flag is set. (Note that there
167 * is also a promise, if the above case is true, not to signal
168 * overruns, either.)
169 */
170 #define TTY_DRIVER_INSTALLED 0x0001
171 #define TTY_DRIVER_RESET_TERMIOS 0x0002
172 #define TTY_DRIVER_REAL_RAW 0x0004
173
174 /* tty driver types */
175 #define TTY_DRIVER_TYPE_SYSTEM 0x0001
176 #define TTY_DRIVER_TYPE_CONSOLE 0x0002
177 #define TTY_DRIVER_TYPE_SERIAL 0x0003
178 #define TTY_DRIVER_TYPE_PTY 0x0004
179 #define TTY_DRIVER_TYPE_SCC 0x0005 /* scc driver */
180
181 /* system subtypes (magic, used by tty_io.c) */
182 #define SYSTEM_TYPE_TTY 0x0001
183 #define SYSTEM_TYPE_CONSOLE 0x0002
184
185 /* pty subtypes (magic, used by tty_io.c) */
186 #define PTY_TYPE_MASTER 0x0001
187 #define PTY_TYPE_SLAVE 0x0002
188
189 #endif /* #ifdef _LINUX_TTY_DRIVER_H */
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*/