Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | #ifndef _LINUX_TTY_LDISC_H |
2 | #define _LINUX_TTY_LDISC_H | |
3 | ||
4 | /* | |
5 | * This structure defines the interface between the tty line discipline | |
6 | * implementation 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 *); | |
11 | * | |
6be06e72 PH |
12 | * This function is called when the line discipline is associated |
13 | * with the tty. The line discipline can use this as an | |
14 | * opportunity to initialize any state needed by the ldisc routines. | |
15 | * | |
1da177e4 LT |
16 | * void (*close)(struct tty_struct *); |
17 | * | |
18 | * This function is called when the line discipline is being | |
6be06e72 PH |
19 | * shutdown, either because the tty is being closed or because |
20 | * the tty is being changed to use a new line discipline | |
21 | * | |
1da177e4 LT |
22 | * void (*flush_buffer)(struct tty_struct *tty); |
23 | * | |
6be06e72 PH |
24 | * This function instructs the line discipline to clear its |
25 | * buffers of any input characters it may have queued to be | |
26 | * delivered to the user mode process. | |
27 | * | |
1da177e4 LT |
28 | * ssize_t (*read)(struct tty_struct * tty, struct file * file, |
29 | * unsigned char * buf, size_t nr); | |
30 | * | |
6be06e72 PH |
31 | * This function is called when the user requests to read from |
32 | * the tty. The line discipline will return whatever characters | |
33 | * it has buffered up for the user. If this function is not | |
34 | * defined, the user will receive an EIO error. | |
35 | * | |
1da177e4 | 36 | * ssize_t (*write)(struct tty_struct * tty, struct file * file, |
6be06e72 PH |
37 | * const unsigned char * buf, size_t nr); |
38 | * | |
39 | * This function is called when the user requests to write to the | |
40 | * tty. The line discipline will deliver the characters to the | |
41 | * low-level tty device for transmission, optionally performing | |
42 | * some processing on the characters first. If this function is | |
43 | * not defined, the user will receive an EIO error. | |
44 | * | |
1da177e4 | 45 | * int (*ioctl)(struct tty_struct * tty, struct file * file, |
6be06e72 | 46 | * unsigned int cmd, unsigned long arg); |
1da177e4 LT |
47 | * |
48 | * This function is called when the user requests an ioctl which | |
6be06e72 PH |
49 | * is not handled by the tty layer or the low-level tty driver. |
50 | * It is intended for ioctls which affect line discpline | |
51 | * operation. Note that the search order for ioctls is (1) tty | |
52 | * layer, (2) tty low-level driver, (3) line discpline. So a | |
53 | * low-level driver can "grab" an ioctl request before the line | |
54 | * discpline has a chance to see it. | |
55 | * | |
e10cc1df | 56 | * long (*compat_ioctl)(struct tty_struct * tty, struct file * file, |
6be06e72 | 57 | * unsigned int cmd, unsigned long arg); |
e10cc1df | 58 | * |
6be06e72 | 59 | * Process ioctl calls from 32-bit process on 64-bit system |
e10cc1df | 60 | * |
edc6afc5 | 61 | * void (*set_termios)(struct tty_struct *tty, struct ktermios * old); |
1da177e4 | 62 | * |
6be06e72 PH |
63 | * This function notifies the line discpline that a change has |
64 | * been made to the termios structure. | |
65 | * | |
1da177e4 | 66 | * int (*poll)(struct tty_struct * tty, struct file * file, |
6be06e72 | 67 | * poll_table *wait); |
1da177e4 | 68 | * |
6be06e72 PH |
69 | * This function is called when a user attempts to select/poll on a |
70 | * tty device. It is solely the responsibility of the line | |
71 | * discipline to handle poll requests. | |
1da177e4 | 72 | * |
55db4c64 | 73 | * void (*receive_buf)(struct tty_struct *, const unsigned char *cp, |
6be06e72 PH |
74 | * char *fp, int count); |
75 | * | |
76 | * This function is called by the low-level tty driver to send | |
77 | * characters received by the hardware to the line discpline for | |
78 | * processing. <cp> is a pointer to the buffer of input | |
79 | * character received by the device. <fp> is a pointer to a | |
80 | * pointer of flag bytes which indicate whether a character was | |
82f91fe0 PH |
81 | * received with a parity error, etc. <fp> may be NULL to indicate |
82 | * all data received is TTY_NORMAL. | |
6be06e72 | 83 | * |
1da177e4 LT |
84 | * void (*write_wakeup)(struct tty_struct *); |
85 | * | |
6be06e72 PH |
86 | * This function is called by the low-level tty driver to signal |
87 | * that line discpline should try to send more characters to the | |
88 | * low-level driver for transmission. If the line discpline does | |
879eb9c3 HS |
89 | * not have any more data to send, it can just return. If the line |
90 | * discipline does have some data to send, please arise a tasklet | |
91 | * or workqueue to do the real data transfer. Do not send data in | |
92 | * this hook, it may leads to a deadlock. | |
1da177e4 LT |
93 | * |
94 | * int (*hangup)(struct tty_struct *) | |
95 | * | |
96 | * Called on a hangup. Tells the discipline that it should | |
97 | * cease I/O to the tty driver. Can sleep. The driver should | |
98 | * seek to perform this action quickly but should wait until | |
99 | * any pending driver I/O is completed. | |
b3e63afe | 100 | * |
593fb1ae | 101 | * void (*dcd_change)(struct tty_struct *tty, unsigned int status) |
b3e63afe | 102 | * |
593fb1ae GS |
103 | * Tells the discipline that the DCD pin has changed its status. |
104 | * Used exclusively by the N_PPS (Pulse-Per-Second) line discipline. | |
24a89d1c PH |
105 | * |
106 | * int (*receive_buf2)(struct tty_struct *, const unsigned char *cp, | |
107 | * char *fp, int count); | |
108 | * | |
109 | * This function is called by the low-level tty driver to send | |
110 | * characters received by the hardware to the line discpline for | |
111 | * processing. <cp> is a pointer to the buffer of input | |
112 | * character received by the device. <fp> is a pointer to a | |
113 | * pointer of flag bytes which indicate whether a character was | |
82f91fe0 PH |
114 | * received with a parity error, etc. <fp> may be NULL to indicate |
115 | * all data received is TTY_NORMAL. | |
24a89d1c | 116 | * If assigned, prefer this function for automatic flow control. |
1da177e4 LT |
117 | */ |
118 | ||
119 | #include <linux/fs.h> | |
120 | #include <linux/wait.h> | |
121 | ||
4898e640 PH |
122 | |
123 | /* | |
124 | * the semaphore definition | |
125 | */ | |
126 | struct ld_semaphore { | |
127 | long count; | |
128 | raw_spinlock_t wait_lock; | |
129 | unsigned int wait_readers; | |
130 | struct list_head read_wait; | |
131 | struct list_head write_wait; | |
132 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
133 | struct lockdep_map dep_map; | |
134 | #endif | |
135 | }; | |
136 | ||
137 | extern void __init_ldsem(struct ld_semaphore *sem, const char *name, | |
138 | struct lock_class_key *key); | |
139 | ||
140 | #define init_ldsem(sem) \ | |
141 | do { \ | |
142 | static struct lock_class_key __key; \ | |
143 | \ | |
144 | __init_ldsem((sem), #sem, &__key); \ | |
145 | } while (0) | |
146 | ||
147 | ||
148 | extern int ldsem_down_read(struct ld_semaphore *sem, long timeout); | |
149 | extern int ldsem_down_read_trylock(struct ld_semaphore *sem); | |
150 | extern int ldsem_down_write(struct ld_semaphore *sem, long timeout); | |
151 | extern int ldsem_down_write_trylock(struct ld_semaphore *sem); | |
152 | extern void ldsem_up_read(struct ld_semaphore *sem); | |
153 | extern void ldsem_up_write(struct ld_semaphore *sem); | |
154 | ||
155 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
156 | extern int ldsem_down_read_nested(struct ld_semaphore *sem, int subclass, | |
157 | long timeout); | |
158 | extern int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass, | |
159 | long timeout); | |
160 | #else | |
161 | # define ldsem_down_read_nested(sem, subclass, timeout) \ | |
162 | ldsem_down_read(sem, timeout) | |
163 | # define ldsem_down_write_nested(sem, subclass, timeout) \ | |
164 | ldsem_down_write(sem, timeout) | |
165 | #endif | |
166 | ||
167 | ||
a352def2 | 168 | struct tty_ldisc_ops { |
1da177e4 LT |
169 | int magic; |
170 | char *name; | |
171 | int num; | |
172 | int flags; | |
6be06e72 | 173 | |
1da177e4 LT |
174 | /* |
175 | * The following routines are called from above. | |
176 | */ | |
177 | int (*open)(struct tty_struct *); | |
178 | void (*close)(struct tty_struct *); | |
179 | void (*flush_buffer)(struct tty_struct *tty); | |
6be06e72 PH |
180 | ssize_t (*read)(struct tty_struct *tty, struct file *file, |
181 | unsigned char __user *buf, size_t nr); | |
182 | ssize_t (*write)(struct tty_struct *tty, struct file *file, | |
183 | const unsigned char *buf, size_t nr); | |
184 | int (*ioctl)(struct tty_struct *tty, struct file *file, | |
1da177e4 | 185 | unsigned int cmd, unsigned long arg); |
6be06e72 | 186 | long (*compat_ioctl)(struct tty_struct *tty, struct file *file, |
e10cc1df | 187 | unsigned int cmd, unsigned long arg); |
6be06e72 | 188 | void (*set_termios)(struct tty_struct *tty, struct ktermios *old); |
1da177e4 LT |
189 | unsigned int (*poll)(struct tty_struct *, struct file *, |
190 | struct poll_table_struct *); | |
191 | int (*hangup)(struct tty_struct *tty); | |
6be06e72 | 192 | |
1da177e4 LT |
193 | /* |
194 | * The following routines are called from below. | |
195 | */ | |
55db4c64 LT |
196 | void (*receive_buf)(struct tty_struct *, const unsigned char *cp, |
197 | char *fp, int count); | |
1da177e4 | 198 | void (*write_wakeup)(struct tty_struct *); |
593fb1ae | 199 | void (*dcd_change)(struct tty_struct *, unsigned int); |
24a89d1c PH |
200 | int (*receive_buf2)(struct tty_struct *, const unsigned char *cp, |
201 | char *fp, int count); | |
1da177e4 LT |
202 | |
203 | struct module *owner; | |
6be06e72 | 204 | |
1da177e4 LT |
205 | int refcount; |
206 | }; | |
207 | ||
a352def2 AC |
208 | struct tty_ldisc { |
209 | struct tty_ldisc_ops *ops; | |
36697529 | 210 | struct tty_struct *tty; |
a352def2 AC |
211 | }; |
212 | ||
1da177e4 LT |
213 | #define TTY_LDISC_MAGIC 0x5403 |
214 | ||
215 | #define LDISC_FLAG_DEFINED 0x00000001 | |
216 | ||
217 | #define MODULE_ALIAS_LDISC(ldisc) \ | |
218 | MODULE_ALIAS("tty-ldisc-" __stringify(ldisc)) | |
219 | ||
220 | #endif /* _LINUX_TTY_LDISC_H */ |