Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Input device TTY line discipline | |
3 | * | |
4 | * Copyright (c) 1999-2002 Vojtech Pavlik | |
5 | * | |
6 | * This is a module that converts a tty line into a much simpler | |
7 | * 'serial io port' abstraction that the input device drivers use. | |
8 | */ | |
9 | ||
10 | /* | |
11 | * This program is free software; you can redistribute it and/or modify it | |
12 | * under the terms of the GNU General Public License version 2 as published by | |
13 | * the Free Software Foundation. | |
14 | */ | |
15 | ||
16 | #include <asm/uaccess.h> | |
17 | #include <linux/kernel.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/serio.h> | |
22 | #include <linux/tty.h> | |
23 | ||
24 | MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>"); | |
25 | MODULE_DESCRIPTION("Input device TTY line discipline"); | |
26 | MODULE_LICENSE("GPL"); | |
27 | MODULE_ALIAS_LDISC(N_MOUSE); | |
28 | ||
29 | #define SERPORT_BUSY 1 | |
1ff2c873 DT |
30 | #define SERPORT_ACTIVE 2 |
31 | #define SERPORT_DEAD 3 | |
1da177e4 LT |
32 | |
33 | struct serport { | |
34 | struct tty_struct *tty; | |
35 | wait_queue_head_t wait; | |
36 | struct serio *serio; | |
1ff2c873 DT |
37 | struct serio_device_id id; |
38 | spinlock_t lock; | |
1da177e4 LT |
39 | unsigned long flags; |
40 | }; | |
41 | ||
42 | /* | |
43 | * Callback functions from the serio code. | |
44 | */ | |
45 | ||
46 | static int serport_serio_write(struct serio *serio, unsigned char data) | |
47 | { | |
48 | struct serport *serport = serio->port_data; | |
49 | return -(serport->tty->driver->write(serport->tty, &data, 1) != 1); | |
50 | } | |
51 | ||
1ff2c873 DT |
52 | static int serport_serio_open(struct serio *serio) |
53 | { | |
54 | struct serport *serport = serio->port_data; | |
55 | unsigned long flags; | |
56 | ||
57 | spin_lock_irqsave(&serport->lock, flags); | |
58 | set_bit(SERPORT_ACTIVE, &serport->flags); | |
59 | spin_unlock_irqrestore(&serport->lock, flags); | |
60 | ||
61 | return 0; | |
62 | } | |
63 | ||
64 | ||
1da177e4 LT |
65 | static void serport_serio_close(struct serio *serio) |
66 | { | |
67 | struct serport *serport = serio->port_data; | |
1ff2c873 DT |
68 | unsigned long flags; |
69 | ||
70 | spin_lock_irqsave(&serport->lock, flags); | |
71 | clear_bit(SERPORT_ACTIVE, &serport->flags); | |
72 | set_bit(SERPORT_DEAD, &serport->flags); | |
73 | spin_unlock_irqrestore(&serport->lock, flags); | |
1da177e4 | 74 | |
1da177e4 LT |
75 | wake_up_interruptible(&serport->wait); |
76 | } | |
77 | ||
78 | /* | |
79 | * serport_ldisc_open() is the routine that is called upon setting our line | |
80 | * discipline on a tty. It prepares the serio struct. | |
81 | */ | |
82 | ||
83 | static int serport_ldisc_open(struct tty_struct *tty) | |
84 | { | |
85 | struct serport *serport; | |
1da177e4 LT |
86 | |
87 | if (!capable(CAP_SYS_ADMIN)) | |
88 | return -EPERM; | |
89 | ||
a97e148a | 90 | serport = kzalloc(sizeof(struct serport), GFP_KERNEL); |
1ff2c873 | 91 | if (!serport) |
1da177e4 | 92 | return -ENOMEM; |
1da177e4 | 93 | |
1da177e4 | 94 | serport->tty = tty; |
1ff2c873 | 95 | spin_lock_init(&serport->lock); |
1da177e4 LT |
96 | init_waitqueue_head(&serport->wait); |
97 | ||
1ff2c873 | 98 | tty->disc_data = serport; |
33f0f88f | 99 | tty->receive_room = 256; |
1ff2c873 DT |
100 | set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
101 | ||
1da177e4 LT |
102 | return 0; |
103 | } | |
104 | ||
105 | /* | |
106 | * serport_ldisc_close() is the opposite of serport_ldisc_open() | |
107 | */ | |
108 | ||
109 | static void serport_ldisc_close(struct tty_struct *tty) | |
110 | { | |
1ff2c873 DT |
111 | struct serport *serport = (struct serport *) tty->disc_data; |
112 | ||
1da177e4 LT |
113 | kfree(serport); |
114 | } | |
115 | ||
116 | /* | |
117 | * serport_ldisc_receive() is called by the low level tty driver when characters | |
118 | * are ready for us. We forward the characters, one by one to the 'interrupt' | |
119 | * routine. | |
1da177e4 LT |
120 | */ |
121 | ||
122 | static void serport_ldisc_receive(struct tty_struct *tty, const unsigned char *cp, char *fp, int count) | |
123 | { | |
124 | struct serport *serport = (struct serport*) tty->disc_data; | |
1ff2c873 | 125 | unsigned long flags; |
1da177e4 | 126 | int i; |
1ff2c873 DT |
127 | |
128 | spin_lock_irqsave(&serport->lock, flags); | |
129 | ||
130 | if (!test_bit(SERPORT_ACTIVE, &serport->flags)) | |
131 | goto out; | |
132 | ||
1da177e4 | 133 | for (i = 0; i < count; i++) |
7d12e780 | 134 | serio_interrupt(serport->serio, cp[i], 0); |
1ff2c873 DT |
135 | |
136 | out: | |
137 | spin_unlock_irqrestore(&serport->lock, flags); | |
1da177e4 LT |
138 | } |
139 | ||
1da177e4 LT |
140 | /* |
141 | * serport_ldisc_read() just waits indefinitely if everything goes well. | |
142 | * However, when the serio driver closes the serio port, it finishes, | |
143 | * returning 0 characters. | |
144 | */ | |
145 | ||
146 | static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, unsigned char __user * buf, size_t nr) | |
147 | { | |
148 | struct serport *serport = (struct serport*) tty->disc_data; | |
1ff2c873 | 149 | struct serio *serio; |
1da177e4 LT |
150 | char name[64]; |
151 | ||
152 | if (test_and_set_bit(SERPORT_BUSY, &serport->flags)) | |
153 | return -EBUSY; | |
154 | ||
a97e148a | 155 | serport->serio = serio = kzalloc(sizeof(struct serio), GFP_KERNEL); |
1ff2c873 DT |
156 | if (!serio) |
157 | return -ENOMEM; | |
158 | ||
159 | strlcpy(serio->name, "Serial port", sizeof(serio->name)); | |
160 | snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", tty_name(tty, name)); | |
161 | serio->id = serport->id; | |
162 | serio->id.type = SERIO_RS232; | |
163 | serio->write = serport_serio_write; | |
164 | serio->open = serport_serio_open; | |
165 | serio->close = serport_serio_close; | |
166 | serio->port_data = serport; | |
167 | ||
1da177e4 LT |
168 | serio_register_port(serport->serio); |
169 | printk(KERN_INFO "serio: Serial port %s\n", tty_name(tty, name)); | |
1ff2c873 DT |
170 | |
171 | wait_event_interruptible(serport->wait, test_bit(SERPORT_DEAD, &serport->flags)); | |
1da177e4 | 172 | serio_unregister_port(serport->serio); |
1ff2c873 | 173 | serport->serio = NULL; |
1da177e4 | 174 | |
1ff2c873 | 175 | clear_bit(SERPORT_DEAD, &serport->flags); |
1da177e4 LT |
176 | clear_bit(SERPORT_BUSY, &serport->flags); |
177 | ||
178 | return 0; | |
179 | } | |
180 | ||
181 | /* | |
182 | * serport_ldisc_ioctl() allows to set the port protocol, and device ID | |
183 | */ | |
184 | ||
185 | static int serport_ldisc_ioctl(struct tty_struct * tty, struct file * file, unsigned int cmd, unsigned long arg) | |
186 | { | |
187 | struct serport *serport = (struct serport*) tty->disc_data; | |
1da177e4 LT |
188 | unsigned long type; |
189 | ||
190 | if (cmd == SPIOCSTYPE) { | |
191 | if (get_user(type, (unsigned long __user *) arg)) | |
192 | return -EFAULT; | |
193 | ||
1ff2c873 DT |
194 | serport->id.proto = type & 0x000000ff; |
195 | serport->id.id = (type & 0x0000ff00) >> 8; | |
196 | serport->id.extra = (type & 0x00ff0000) >> 16; | |
1da177e4 LT |
197 | |
198 | return 0; | |
199 | } | |
200 | ||
201 | return -EINVAL; | |
202 | } | |
203 | ||
204 | static void serport_ldisc_write_wakeup(struct tty_struct * tty) | |
205 | { | |
1ff2c873 DT |
206 | struct serport *serport = (struct serport *) tty->disc_data; |
207 | unsigned long flags; | |
1da177e4 | 208 | |
1ff2c873 DT |
209 | spin_lock_irqsave(&serport->lock, flags); |
210 | if (test_bit(SERPORT_ACTIVE, &serport->flags)) | |
211 | serio_drv_write_wakeup(serport->serio); | |
212 | spin_unlock_irqrestore(&serport->lock, flags); | |
1da177e4 LT |
213 | } |
214 | ||
215 | /* | |
216 | * The line discipline structure. | |
217 | */ | |
218 | ||
219 | static struct tty_ldisc serport_ldisc = { | |
220 | .owner = THIS_MODULE, | |
221 | .name = "input", | |
222 | .open = serport_ldisc_open, | |
223 | .close = serport_ldisc_close, | |
224 | .read = serport_ldisc_read, | |
225 | .ioctl = serport_ldisc_ioctl, | |
226 | .receive_buf = serport_ldisc_receive, | |
1da177e4 LT |
227 | .write_wakeup = serport_ldisc_write_wakeup |
228 | }; | |
229 | ||
230 | /* | |
231 | * The functions for insering/removing us as a module. | |
232 | */ | |
233 | ||
234 | static int __init serport_init(void) | |
235 | { | |
236 | int retval; | |
237 | retval = tty_register_ldisc(N_MOUSE, &serport_ldisc); | |
238 | if (retval) | |
239 | printk(KERN_ERR "serport.c: Error registering line discipline.\n"); | |
240 | ||
241 | return retval; | |
242 | } | |
243 | ||
244 | static void __exit serport_exit(void) | |
245 | { | |
64ccd715 | 246 | tty_unregister_ldisc(N_MOUSE); |
1da177e4 LT |
247 | } |
248 | ||
249 | module_init(serport_init); | |
250 | module_exit(serport_exit); |