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> | |
d43c36dc | 18 | #include <linux/sched.h> |
1da177e4 LT |
19 | #include <linux/slab.h> |
20 | #include <linux/module.h> | |
21 | #include <linux/init.h> | |
22 | #include <linux/serio.h> | |
23 | #include <linux/tty.h> | |
24 | ||
25 | MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>"); | |
26 | MODULE_DESCRIPTION("Input device TTY line discipline"); | |
27 | MODULE_LICENSE("GPL"); | |
28 | MODULE_ALIAS_LDISC(N_MOUSE); | |
29 | ||
30 | #define SERPORT_BUSY 1 | |
1ff2c873 DT |
31 | #define SERPORT_ACTIVE 2 |
32 | #define SERPORT_DEAD 3 | |
1da177e4 LT |
33 | |
34 | struct serport { | |
35 | struct tty_struct *tty; | |
36 | wait_queue_head_t wait; | |
37 | struct serio *serio; | |
1ff2c873 DT |
38 | struct serio_device_id id; |
39 | spinlock_t lock; | |
1da177e4 LT |
40 | unsigned long flags; |
41 | }; | |
42 | ||
43 | /* | |
44 | * Callback functions from the serio code. | |
45 | */ | |
46 | ||
47 | static int serport_serio_write(struct serio *serio, unsigned char data) | |
48 | { | |
49 | struct serport *serport = serio->port_data; | |
f34d7a5b | 50 | return -(serport->tty->ops->write(serport->tty, &data, 1) != 1); |
1da177e4 LT |
51 | } |
52 | ||
1ff2c873 DT |
53 | static int serport_serio_open(struct serio *serio) |
54 | { | |
55 | struct serport *serport = serio->port_data; | |
56 | unsigned long flags; | |
57 | ||
58 | spin_lock_irqsave(&serport->lock, flags); | |
59 | set_bit(SERPORT_ACTIVE, &serport->flags); | |
60 | spin_unlock_irqrestore(&serport->lock, flags); | |
61 | ||
62 | return 0; | |
63 | } | |
64 | ||
65 | ||
1da177e4 LT |
66 | static void serport_serio_close(struct serio *serio) |
67 | { | |
68 | struct serport *serport = serio->port_data; | |
1ff2c873 DT |
69 | unsigned long flags; |
70 | ||
71 | spin_lock_irqsave(&serport->lock, flags); | |
72 | clear_bit(SERPORT_ACTIVE, &serport->flags); | |
73 | set_bit(SERPORT_DEAD, &serport->flags); | |
74 | spin_unlock_irqrestore(&serport->lock, flags); | |
1da177e4 | 75 | |
1da177e4 LT |
76 | wake_up_interruptible(&serport->wait); |
77 | } | |
78 | ||
79 | /* | |
80 | * serport_ldisc_open() is the routine that is called upon setting our line | |
81 | * discipline on a tty. It prepares the serio struct. | |
82 | */ | |
83 | ||
84 | static int serport_ldisc_open(struct tty_struct *tty) | |
85 | { | |
86 | struct serport *serport; | |
1da177e4 LT |
87 | |
88 | if (!capable(CAP_SYS_ADMIN)) | |
89 | return -EPERM; | |
90 | ||
a97e148a | 91 | serport = kzalloc(sizeof(struct serport), GFP_KERNEL); |
1ff2c873 | 92 | if (!serport) |
1da177e4 | 93 | return -ENOMEM; |
1da177e4 | 94 | |
1da177e4 | 95 | serport->tty = tty; |
1ff2c873 | 96 | spin_lock_init(&serport->lock); |
1da177e4 LT |
97 | init_waitqueue_head(&serport->wait); |
98 | ||
1ff2c873 | 99 | tty->disc_data = serport; |
33f0f88f | 100 | tty->receive_room = 256; |
1ff2c873 DT |
101 | set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
102 | ||
1da177e4 LT |
103 | return 0; |
104 | } | |
105 | ||
106 | /* | |
107 | * serport_ldisc_close() is the opposite of serport_ldisc_open() | |
108 | */ | |
109 | ||
110 | static void serport_ldisc_close(struct tty_struct *tty) | |
111 | { | |
1ff2c873 DT |
112 | struct serport *serport = (struct serport *) tty->disc_data; |
113 | ||
1da177e4 LT |
114 | kfree(serport); |
115 | } | |
116 | ||
117 | /* | |
118 | * serport_ldisc_receive() is called by the low level tty driver when characters | |
119 | * are ready for us. We forward the characters, one by one to the 'interrupt' | |
120 | * routine. | |
1da177e4 LT |
121 | */ |
122 | ||
123 | static void serport_ldisc_receive(struct tty_struct *tty, const unsigned char *cp, char *fp, int count) | |
124 | { | |
125 | struct serport *serport = (struct serport*) tty->disc_data; | |
1ff2c873 | 126 | unsigned long flags; |
1da177e4 | 127 | int i; |
1ff2c873 DT |
128 | |
129 | spin_lock_irqsave(&serport->lock, flags); | |
130 | ||
131 | if (!test_bit(SERPORT_ACTIVE, &serport->flags)) | |
132 | goto out; | |
133 | ||
1da177e4 | 134 | for (i = 0; i < count; i++) |
7d12e780 | 135 | serio_interrupt(serport->serio, cp[i], 0); |
1ff2c873 DT |
136 | |
137 | out: | |
138 | spin_unlock_irqrestore(&serport->lock, flags); | |
1da177e4 LT |
139 | } |
140 | ||
1da177e4 LT |
141 | /* |
142 | * serport_ldisc_read() just waits indefinitely if everything goes well. | |
143 | * However, when the serio driver closes the serio port, it finishes, | |
144 | * returning 0 characters. | |
145 | */ | |
146 | ||
147 | static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, unsigned char __user * buf, size_t nr) | |
148 | { | |
149 | struct serport *serport = (struct serport*) tty->disc_data; | |
1ff2c873 | 150 | struct serio *serio; |
1da177e4 LT |
151 | char name[64]; |
152 | ||
153 | if (test_and_set_bit(SERPORT_BUSY, &serport->flags)) | |
154 | return -EBUSY; | |
155 | ||
a97e148a | 156 | serport->serio = serio = kzalloc(sizeof(struct serio), GFP_KERNEL); |
1ff2c873 DT |
157 | if (!serio) |
158 | return -ENOMEM; | |
159 | ||
160 | strlcpy(serio->name, "Serial port", sizeof(serio->name)); | |
161 | snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", tty_name(tty, name)); | |
162 | serio->id = serport->id; | |
163 | serio->id.type = SERIO_RS232; | |
164 | serio->write = serport_serio_write; | |
165 | serio->open = serport_serio_open; | |
166 | serio->close = serport_serio_close; | |
167 | serio->port_data = serport; | |
168 | ||
1da177e4 LT |
169 | serio_register_port(serport->serio); |
170 | printk(KERN_INFO "serio: Serial port %s\n", tty_name(tty, name)); | |
1ff2c873 DT |
171 | |
172 | wait_event_interruptible(serport->wait, test_bit(SERPORT_DEAD, &serport->flags)); | |
1da177e4 | 173 | serio_unregister_port(serport->serio); |
1ff2c873 | 174 | serport->serio = NULL; |
1da177e4 | 175 | |
1ff2c873 | 176 | clear_bit(SERPORT_DEAD, &serport->flags); |
1da177e4 LT |
177 | clear_bit(SERPORT_BUSY, &serport->flags); |
178 | ||
179 | return 0; | |
180 | } | |
181 | ||
182 | /* | |
183 | * serport_ldisc_ioctl() allows to set the port protocol, and device ID | |
184 | */ | |
185 | ||
186 | static int serport_ldisc_ioctl(struct tty_struct * tty, struct file * file, unsigned int cmd, unsigned long arg) | |
187 | { | |
188 | struct serport *serport = (struct serport*) tty->disc_data; | |
1da177e4 LT |
189 | unsigned long type; |
190 | ||
191 | if (cmd == SPIOCSTYPE) { | |
192 | if (get_user(type, (unsigned long __user *) arg)) | |
193 | return -EFAULT; | |
194 | ||
1ff2c873 DT |
195 | serport->id.proto = type & 0x000000ff; |
196 | serport->id.id = (type & 0x0000ff00) >> 8; | |
197 | serport->id.extra = (type & 0x00ff0000) >> 16; | |
1da177e4 LT |
198 | |
199 | return 0; | |
200 | } | |
201 | ||
202 | return -EINVAL; | |
203 | } | |
204 | ||
205 | static void serport_ldisc_write_wakeup(struct tty_struct * tty) | |
206 | { | |
1ff2c873 DT |
207 | struct serport *serport = (struct serport *) tty->disc_data; |
208 | unsigned long flags; | |
1da177e4 | 209 | |
1ff2c873 DT |
210 | spin_lock_irqsave(&serport->lock, flags); |
211 | if (test_bit(SERPORT_ACTIVE, &serport->flags)) | |
212 | serio_drv_write_wakeup(serport->serio); | |
213 | spin_unlock_irqrestore(&serport->lock, flags); | |
1da177e4 LT |
214 | } |
215 | ||
216 | /* | |
217 | * The line discipline structure. | |
218 | */ | |
219 | ||
a352def2 | 220 | static struct tty_ldisc_ops serport_ldisc = { |
1da177e4 LT |
221 | .owner = THIS_MODULE, |
222 | .name = "input", | |
223 | .open = serport_ldisc_open, | |
224 | .close = serport_ldisc_close, | |
225 | .read = serport_ldisc_read, | |
226 | .ioctl = serport_ldisc_ioctl, | |
227 | .receive_buf = serport_ldisc_receive, | |
1da177e4 LT |
228 | .write_wakeup = serport_ldisc_write_wakeup |
229 | }; | |
230 | ||
231 | /* | |
232 | * The functions for insering/removing us as a module. | |
233 | */ | |
234 | ||
235 | static int __init serport_init(void) | |
236 | { | |
237 | int retval; | |
238 | retval = tty_register_ldisc(N_MOUSE, &serport_ldisc); | |
239 | if (retval) | |
240 | printk(KERN_ERR "serport.c: Error registering line discipline.\n"); | |
241 | ||
242 | return retval; | |
243 | } | |
244 | ||
245 | static void __exit serport_exit(void) | |
246 | { | |
64ccd715 | 247 | tty_unregister_ldisc(N_MOUSE); |
1da177e4 LT |
248 | } |
249 | ||
250 | module_init(serport_init); | |
251 | module_exit(serport_exit); |