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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Alexey Dobriyand43c36d2009-10-07 17:09:06 +040018#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/slab.h>
20#include <linux/module.h>
21#include <linux/init.h>
22#include <linux/serio.h>
23#include <linux/tty.h>
John Sunga80d8b02014-09-09 10:06:51 -070024#include <linux/compat.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
26MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
27MODULE_DESCRIPTION("Input device TTY line discipline");
28MODULE_LICENSE("GPL");
29MODULE_ALIAS_LDISC(N_MOUSE);
30
31#define SERPORT_BUSY 1
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -070032#define SERPORT_ACTIVE 2
33#define SERPORT_DEAD 3
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
35struct serport {
36 struct tty_struct *tty;
37 wait_queue_head_t wait;
38 struct serio *serio;
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -070039 struct serio_device_id id;
40 spinlock_t lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 unsigned long flags;
42};
43
44/*
45 * Callback functions from the serio code.
46 */
47
48static int serport_serio_write(struct serio *serio, unsigned char data)
49{
50 struct serport *serport = serio->port_data;
Alan Coxf34d7a52008-04-30 00:54:13 -070051 return -(serport->tty->ops->write(serport->tty, &data, 1) != 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -070052}
53
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -070054static int serport_serio_open(struct serio *serio)
55{
56 struct serport *serport = serio->port_data;
57 unsigned long flags;
58
59 spin_lock_irqsave(&serport->lock, flags);
60 set_bit(SERPORT_ACTIVE, &serport->flags);
61 spin_unlock_irqrestore(&serport->lock, flags);
62
63 return 0;
64}
65
66
Linus Torvalds1da177e2005-04-16 15:20:36 -070067static void serport_serio_close(struct serio *serio)
68{
69 struct serport *serport = serio->port_data;
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -070070 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -070072 spin_lock_irqsave(&serport->lock, flags);
73 clear_bit(SERPORT_ACTIVE, &serport->flags);
74 set_bit(SERPORT_DEAD, &serport->flags);
75 spin_unlock_irqrestore(&serport->lock, flags);
76
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 wake_up_interruptible(&serport->wait);
78}
79
80/*
81 * serport_ldisc_open() is the routine that is called upon setting our line
82 * discipline on a tty. It prepares the serio struct.
83 */
84
85static int serport_ldisc_open(struct tty_struct *tty)
86{
87 struct serport *serport;
Linus Torvalds1da177e2005-04-16 15:20:36 -070088
89 if (!capable(CAP_SYS_ADMIN))
90 return -EPERM;
91
Pekka Enberga97e1482005-09-06 15:18:33 -070092 serport = kzalloc(sizeof(struct serport), GFP_KERNEL);
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -070093 if (!serport)
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 serport->tty = tty;
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -070097 spin_lock_init(&serport->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 init_waitqueue_head(&serport->wait);
99
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700100 tty->disc_data = serport;
Alan Cox33f0f882006-01-09 20:54:13 -0800101 tty->receive_room = 256;
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700102 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
103
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 return 0;
105}
106
107/*
108 * serport_ldisc_close() is the opposite of serport_ldisc_open()
109 */
110
111static void serport_ldisc_close(struct tty_struct *tty)
112{
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700113 struct serport *serport = (struct serport *) tty->disc_data;
114
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 kfree(serport);
116}
117
118/*
119 * serport_ldisc_receive() is called by the low level tty driver when characters
David Engraf48c27012011-01-20 23:05:17 -0800120 * are ready for us. We forward the characters and flags, one by one to the
121 * 'interrupt' routine.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 */
123
Linus Torvalds55db4c62011-06-04 06:33:24 +0900124static void serport_ldisc_receive(struct tty_struct *tty, const unsigned char *cp, char *fp, int count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125{
126 struct serport *serport = (struct serport*) tty->disc_data;
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700127 unsigned long flags;
Peter Hurley82f91fe2013-12-02 13:56:03 -0500128 unsigned int ch_flags = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 int i;
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700130
131 spin_lock_irqsave(&serport->lock, flags);
132
Linus Torvalds55db4c62011-06-04 06:33:24 +0900133 if (!test_bit(SERPORT_ACTIVE, &serport->flags))
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700134 goto out;
135
David Engraf48c27012011-01-20 23:05:17 -0800136 for (i = 0; i < count; i++) {
Peter Hurley82f91fe2013-12-02 13:56:03 -0500137 if (fp) {
138 switch (fp[i]) {
139 case TTY_FRAME:
140 ch_flags = SERIO_FRAME;
141 break;
David Engraf48c27012011-01-20 23:05:17 -0800142
Peter Hurley82f91fe2013-12-02 13:56:03 -0500143 case TTY_PARITY:
144 ch_flags = SERIO_PARITY;
145 break;
David Engraf48c27012011-01-20 23:05:17 -0800146
Peter Hurley82f91fe2013-12-02 13:56:03 -0500147 default:
148 ch_flags = 0;
149 break;
150 }
David Engraf48c27012011-01-20 23:05:17 -0800151 }
152
153 serio_interrupt(serport->serio, cp[i], ch_flags);
154 }
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700155
156out:
157 spin_unlock_irqrestore(&serport->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158}
159
160/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 * serport_ldisc_read() just waits indefinitely if everything goes well.
162 * However, when the serio driver closes the serio port, it finishes,
163 * returning 0 characters.
164 */
165
166static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, unsigned char __user * buf, size_t nr)
167{
168 struct serport *serport = (struct serport*) tty->disc_data;
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700169 struct serio *serio;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 char name[64];
171
172 if (test_and_set_bit(SERPORT_BUSY, &serport->flags))
173 return -EBUSY;
174
Pekka Enberga97e1482005-09-06 15:18:33 -0700175 serport->serio = serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700176 if (!serio)
177 return -ENOMEM;
178
179 strlcpy(serio->name, "Serial port", sizeof(serio->name));
180 snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", tty_name(tty, name));
181 serio->id = serport->id;
182 serio->id.type = SERIO_RS232;
183 serio->write = serport_serio_write;
184 serio->open = serport_serio_open;
185 serio->close = serport_serio_close;
186 serio->port_data = serport;
Dmitry Eremin-Solenikovde838a92010-08-09 18:22:50 +0400187 serio->dev.parent = tty->dev;
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700188
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 serio_register_port(serport->serio);
190 printk(KERN_INFO "serio: Serial port %s\n", tty_name(tty, name));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700192 wait_event_interruptible(serport->wait, test_bit(SERPORT_DEAD, &serport->flags));
193 serio_unregister_port(serport->serio);
194 serport->serio = NULL;
195
196 clear_bit(SERPORT_DEAD, &serport->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 clear_bit(SERPORT_BUSY, &serport->flags);
198
199 return 0;
200}
201
John Sunga80d8b02014-09-09 10:06:51 -0700202static void serport_set_type(struct tty_struct *tty, unsigned long type)
203{
204 struct serport *serport = tty->disc_data;
205
206 serport->id.proto = type & 0x000000ff;
207 serport->id.id = (type & 0x0000ff00) >> 8;
208 serport->id.extra = (type & 0x00ff0000) >> 16;
209}
210
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211/*
212 * serport_ldisc_ioctl() allows to set the port protocol, and device ID
213 */
214
John Sunga80d8b02014-09-09 10:06:51 -0700215static int serport_ldisc_ioctl(struct tty_struct *tty, struct file *file,
216 unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 if (cmd == SPIOCSTYPE) {
John Sunga80d8b02014-09-09 10:06:51 -0700219 unsigned long type;
220
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 if (get_user(type, (unsigned long __user *) arg))
222 return -EFAULT;
223
John Sunga80d8b02014-09-09 10:06:51 -0700224 serport_set_type(tty, type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 return 0;
226 }
227
228 return -EINVAL;
229}
230
John Sunga80d8b02014-09-09 10:06:51 -0700231#ifdef CONFIG_COMPAT
232#define COMPAT_SPIOCSTYPE _IOW('q', 0x01, compat_ulong_t)
233static long serport_ldisc_compat_ioctl(struct tty_struct *tty,
234 struct file *file,
235 unsigned int cmd, unsigned long arg)
236{
237 if (cmd == COMPAT_SPIOCSTYPE) {
238 void __user *uarg = compat_ptr(arg);
239 compat_ulong_t compat_type;
240
241 if (get_user(compat_type, (compat_ulong_t __user *)uarg))
242 return -EFAULT;
243
244 serport_set_type(tty, compat_type);
245 return 0;
246 }
247
248 return -EINVAL;
249}
250#endif
251
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252static void serport_ldisc_write_wakeup(struct tty_struct * tty)
253{
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700254 struct serport *serport = (struct serport *) tty->disc_data;
255 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700257 spin_lock_irqsave(&serport->lock, flags);
258 if (test_bit(SERPORT_ACTIVE, &serport->flags))
259 serio_drv_write_wakeup(serport->serio);
260 spin_unlock_irqrestore(&serport->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261}
262
263/*
264 * The line discipline structure.
265 */
266
Alan Coxa352def2008-07-16 21:53:12 +0100267static struct tty_ldisc_ops serport_ldisc = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 .owner = THIS_MODULE,
269 .name = "input",
270 .open = serport_ldisc_open,
271 .close = serport_ldisc_close,
272 .read = serport_ldisc_read,
273 .ioctl = serport_ldisc_ioctl,
John Sunga80d8b02014-09-09 10:06:51 -0700274#ifdef CONFIG_COMPAT
275 .compat_ioctl = serport_ldisc_compat_ioctl,
276#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 .receive_buf = serport_ldisc_receive,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 .write_wakeup = serport_ldisc_write_wakeup
279};
280
281/*
282 * The functions for insering/removing us as a module.
283 */
284
285static int __init serport_init(void)
286{
287 int retval;
288 retval = tty_register_ldisc(N_MOUSE, &serport_ldisc);
289 if (retval)
290 printk(KERN_ERR "serport.c: Error registering line discipline.\n");
291
292 return retval;
293}
294
295static void __exit serport_exit(void)
296{
Alexey Dobriyan64ccd712005-06-23 00:10:33 -0700297 tty_unregister_ldisc(N_MOUSE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298}
299
300module_init(serport_init);
301module_exit(serport_exit);