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 DT |
98 | tty->disc_data = serport; |
99 | set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); | |
100 | ||
1da177e4 LT |
101 | return 0; |
102 | } | |
103 | ||
104 | /* | |
105 | * serport_ldisc_close() is the opposite of serport_ldisc_open() | |
106 | */ | |
107 | ||
108 | static void serport_ldisc_close(struct tty_struct *tty) | |
109 | { | |
1ff2c873 DT |
110 | struct serport *serport = (struct serport *) tty->disc_data; |
111 | ||
1da177e4 LT |
112 | kfree(serport); |
113 | } | |
114 | ||
115 | /* | |
116 | * serport_ldisc_receive() is called by the low level tty driver when characters | |
117 | * are ready for us. We forward the characters, one by one to the 'interrupt' | |
118 | * routine. | |
119 | * | |
120 | * FIXME: We should get pt_regs from the tty layer and forward them to | |
121 | * serio_interrupt here. | |
122 | */ | |
123 | ||
124 | static void serport_ldisc_receive(struct tty_struct *tty, const unsigned char *cp, char *fp, int count) | |
125 | { | |
126 | struct serport *serport = (struct serport*) tty->disc_data; | |
1ff2c873 | 127 | unsigned long flags; |
1da177e4 | 128 | int i; |
1ff2c873 DT |
129 | |
130 | spin_lock_irqsave(&serport->lock, flags); | |
131 | ||
132 | if (!test_bit(SERPORT_ACTIVE, &serport->flags)) | |
133 | goto out; | |
134 | ||
1da177e4 LT |
135 | for (i = 0; i < count; i++) |
136 | serio_interrupt(serport->serio, cp[i], 0, NULL); | |
1ff2c873 DT |
137 | |
138 | out: | |
139 | spin_unlock_irqrestore(&serport->lock, flags); | |
1da177e4 LT |
140 | } |
141 | ||
142 | /* | |
143 | * serport_ldisc_room() reports how much room we do have for receiving data. | |
144 | * Although we in fact have infinite room, we need to specify some value | |
145 | * here, and 256 seems to be reasonable. | |
146 | */ | |
147 | ||
148 | static int serport_ldisc_room(struct tty_struct *tty) | |
149 | { | |
150 | return 256; | |
151 | } | |
152 | ||
153 | /* | |
154 | * serport_ldisc_read() just waits indefinitely if everything goes well. | |
155 | * However, when the serio driver closes the serio port, it finishes, | |
156 | * returning 0 characters. | |
157 | */ | |
158 | ||
159 | static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, unsigned char __user * buf, size_t nr) | |
160 | { | |
161 | struct serport *serport = (struct serport*) tty->disc_data; | |
1ff2c873 | 162 | struct serio *serio; |
1da177e4 LT |
163 | char name[64]; |
164 | ||
165 | if (test_and_set_bit(SERPORT_BUSY, &serport->flags)) | |
166 | return -EBUSY; | |
167 | ||
a97e148a | 168 | serport->serio = serio = kzalloc(sizeof(struct serio), GFP_KERNEL); |
1ff2c873 DT |
169 | if (!serio) |
170 | return -ENOMEM; | |
171 | ||
172 | strlcpy(serio->name, "Serial port", sizeof(serio->name)); | |
173 | snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", tty_name(tty, name)); | |
174 | serio->id = serport->id; | |
175 | serio->id.type = SERIO_RS232; | |
176 | serio->write = serport_serio_write; | |
177 | serio->open = serport_serio_open; | |
178 | serio->close = serport_serio_close; | |
179 | serio->port_data = serport; | |
180 | ||
1da177e4 LT |
181 | serio_register_port(serport->serio); |
182 | printk(KERN_INFO "serio: Serial port %s\n", tty_name(tty, name)); | |
1ff2c873 DT |
183 | |
184 | wait_event_interruptible(serport->wait, test_bit(SERPORT_DEAD, &serport->flags)); | |
1da177e4 | 185 | serio_unregister_port(serport->serio); |
1ff2c873 | 186 | serport->serio = NULL; |
1da177e4 | 187 | |
1ff2c873 | 188 | clear_bit(SERPORT_DEAD, &serport->flags); |
1da177e4 LT |
189 | clear_bit(SERPORT_BUSY, &serport->flags); |
190 | ||
191 | return 0; | |
192 | } | |
193 | ||
194 | /* | |
195 | * serport_ldisc_ioctl() allows to set the port protocol, and device ID | |
196 | */ | |
197 | ||
198 | static int serport_ldisc_ioctl(struct tty_struct * tty, struct file * file, unsigned int cmd, unsigned long arg) | |
199 | { | |
200 | struct serport *serport = (struct serport*) tty->disc_data; | |
1da177e4 LT |
201 | unsigned long type; |
202 | ||
203 | if (cmd == SPIOCSTYPE) { | |
204 | if (get_user(type, (unsigned long __user *) arg)) | |
205 | return -EFAULT; | |
206 | ||
1ff2c873 DT |
207 | serport->id.proto = type & 0x000000ff; |
208 | serport->id.id = (type & 0x0000ff00) >> 8; | |
209 | serport->id.extra = (type & 0x00ff0000) >> 16; | |
1da177e4 LT |
210 | |
211 | return 0; | |
212 | } | |
213 | ||
214 | return -EINVAL; | |
215 | } | |
216 | ||
217 | static void serport_ldisc_write_wakeup(struct tty_struct * tty) | |
218 | { | |
1ff2c873 DT |
219 | struct serport *serport = (struct serport *) tty->disc_data; |
220 | unsigned long flags; | |
1da177e4 | 221 | |
1ff2c873 DT |
222 | spin_lock_irqsave(&serport->lock, flags); |
223 | if (test_bit(SERPORT_ACTIVE, &serport->flags)) | |
224 | serio_drv_write_wakeup(serport->serio); | |
225 | spin_unlock_irqrestore(&serport->lock, flags); | |
1da177e4 LT |
226 | } |
227 | ||
228 | /* | |
229 | * The line discipline structure. | |
230 | */ | |
231 | ||
232 | static struct tty_ldisc serport_ldisc = { | |
233 | .owner = THIS_MODULE, | |
234 | .name = "input", | |
235 | .open = serport_ldisc_open, | |
236 | .close = serport_ldisc_close, | |
237 | .read = serport_ldisc_read, | |
238 | .ioctl = serport_ldisc_ioctl, | |
239 | .receive_buf = serport_ldisc_receive, | |
240 | .receive_room = serport_ldisc_room, | |
241 | .write_wakeup = serport_ldisc_write_wakeup | |
242 | }; | |
243 | ||
244 | /* | |
245 | * The functions for insering/removing us as a module. | |
246 | */ | |
247 | ||
248 | static int __init serport_init(void) | |
249 | { | |
250 | int retval; | |
251 | retval = tty_register_ldisc(N_MOUSE, &serport_ldisc); | |
252 | if (retval) | |
253 | printk(KERN_ERR "serport.c: Error registering line discipline.\n"); | |
254 | ||
255 | return retval; | |
256 | } | |
257 | ||
258 | static void __exit serport_exit(void) | |
259 | { | |
64ccd715 | 260 | tty_unregister_ldisc(N_MOUSE); |
1da177e4 LT |
261 | } |
262 | ||
263 | module_init(serport_init); | |
264 | module_exit(serport_exit); |