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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>
24
25MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
26MODULE_DESCRIPTION("Input device TTY line discipline");
27MODULE_LICENSE("GPL");
28MODULE_ALIAS_LDISC(N_MOUSE);
29
30#define SERPORT_BUSY 1
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -070031#define SERPORT_ACTIVE 2
32#define SERPORT_DEAD 3
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34struct serport {
35 struct tty_struct *tty;
36 wait_queue_head_t wait;
37 struct serio *serio;
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -070038 struct serio_device_id id;
39 spinlock_t lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 unsigned long flags;
41};
42
43/*
44 * Callback functions from the serio code.
45 */
46
47static int serport_serio_write(struct serio *serio, unsigned char data)
48{
49 struct serport *serport = serio->port_data;
Alan Coxf34d7a52008-04-30 00:54:13 -070050 return -(serport->tty->ops->write(serport->tty, &data, 1) != 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -070051}
52
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -070053static 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070066static void serport_serio_close(struct serio *serio)
67{
68 struct serport *serport = serio->port_data;
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -070069 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -070070
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -070071 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);
75
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 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
84static int serport_ldisc_open(struct tty_struct *tty)
85{
86 struct serport *serport;
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
88 if (!capable(CAP_SYS_ADMIN))
89 return -EPERM;
90
Pekka Enberga97e1482005-09-06 15:18:33 -070091 serport = kzalloc(sizeof(struct serport), GFP_KERNEL);
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -070092 if (!serport)
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -070094
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 serport->tty = tty;
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -070096 spin_lock_init(&serport->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 init_waitqueue_head(&serport->wait);
98
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -070099 tty->disc_data = serport;
Alan Cox33f0f882006-01-09 20:54:13 -0800100 tty->receive_room = 256;
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700101 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
102
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 return 0;
104}
105
106/*
107 * serport_ldisc_close() is the opposite of serport_ldisc_open()
108 */
109
110static void serport_ldisc_close(struct tty_struct *tty)
111{
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700112 struct serport *serport = (struct serport *) tty->disc_data;
113
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 kfree(serport);
115}
116
117/*
118 * serport_ldisc_receive() is called by the low level tty driver when characters
David Engraf48c27012011-01-20 23:05:17 -0800119 * are ready for us. We forward the characters and flags, one by one to the
120 * 'interrupt' routine.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 */
122
Linus Torvalds55db4c62011-06-04 06:33:24 +0900123static void serport_ldisc_receive(struct tty_struct *tty, const unsigned char *cp, char *fp, int count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124{
125 struct serport *serport = (struct serport*) tty->disc_data;
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700126 unsigned long flags;
David Engraf48c27012011-01-20 23:05:17 -0800127 unsigned int ch_flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 int i;
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700129
130 spin_lock_irqsave(&serport->lock, flags);
131
Linus Torvalds55db4c62011-06-04 06:33:24 +0900132 if (!test_bit(SERPORT_ACTIVE, &serport->flags))
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700133 goto out;
134
David Engraf48c27012011-01-20 23:05:17 -0800135 for (i = 0; i < count; i++) {
136 switch (fp[i]) {
137 case TTY_FRAME:
138 ch_flags = SERIO_FRAME;
139 break;
140
141 case TTY_PARITY:
142 ch_flags = SERIO_PARITY;
143 break;
144
145 default:
146 ch_flags = 0;
147 break;
148 }
149
150 serio_interrupt(serport->serio, cp[i], ch_flags);
151 }
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700152
153out:
154 spin_unlock_irqrestore(&serport->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155}
156
157/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 * serport_ldisc_read() just waits indefinitely if everything goes well.
159 * However, when the serio driver closes the serio port, it finishes,
160 * returning 0 characters.
161 */
162
163static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, unsigned char __user * buf, size_t nr)
164{
165 struct serport *serport = (struct serport*) tty->disc_data;
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700166 struct serio *serio;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 char name[64];
168
169 if (test_and_set_bit(SERPORT_BUSY, &serport->flags))
170 return -EBUSY;
171
Pekka Enberga97e1482005-09-06 15:18:33 -0700172 serport->serio = serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700173 if (!serio)
174 return -ENOMEM;
175
176 strlcpy(serio->name, "Serial port", sizeof(serio->name));
177 snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", tty_name(tty, name));
178 serio->id = serport->id;
179 serio->id.type = SERIO_RS232;
180 serio->write = serport_serio_write;
181 serio->open = serport_serio_open;
182 serio->close = serport_serio_close;
183 serio->port_data = serport;
Dmitry Eremin-Solenikovde838a92010-08-09 18:22:50 +0400184 serio->dev.parent = tty->dev;
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700185
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 serio_register_port(serport->serio);
187 printk(KERN_INFO "serio: Serial port %s\n", tty_name(tty, name));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700189 wait_event_interruptible(serport->wait, test_bit(SERPORT_DEAD, &serport->flags));
190 serio_unregister_port(serport->serio);
191 serport->serio = NULL;
192
193 clear_bit(SERPORT_DEAD, &serport->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 clear_bit(SERPORT_BUSY, &serport->flags);
195
196 return 0;
197}
198
199/*
200 * serport_ldisc_ioctl() allows to set the port protocol, and device ID
201 */
202
203static int serport_ldisc_ioctl(struct tty_struct * tty, struct file * file, unsigned int cmd, unsigned long arg)
204{
205 struct serport *serport = (struct serport*) tty->disc_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 unsigned long type;
207
208 if (cmd == SPIOCSTYPE) {
209 if (get_user(type, (unsigned long __user *) arg))
210 return -EFAULT;
211
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700212 serport->id.proto = type & 0x000000ff;
213 serport->id.id = (type & 0x0000ff00) >> 8;
214 serport->id.extra = (type & 0x00ff0000) >> 16;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
216 return 0;
217 }
218
219 return -EINVAL;
220}
221
222static void serport_ldisc_write_wakeup(struct tty_struct * tty)
223{
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700224 struct serport *serport = (struct serport *) tty->disc_data;
225 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226
Dmitry Torokhov1ff2c872005-05-16 21:53:07 -0700227 spin_lock_irqsave(&serport->lock, flags);
228 if (test_bit(SERPORT_ACTIVE, &serport->flags))
229 serio_drv_write_wakeup(serport->serio);
230 spin_unlock_irqrestore(&serport->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231}
232
233/*
234 * The line discipline structure.
235 */
236
Alan Coxa352def2008-07-16 21:53:12 +0100237static struct tty_ldisc_ops serport_ldisc = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 .owner = THIS_MODULE,
239 .name = "input",
240 .open = serport_ldisc_open,
241 .close = serport_ldisc_close,
242 .read = serport_ldisc_read,
243 .ioctl = serport_ldisc_ioctl,
244 .receive_buf = serport_ldisc_receive,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 .write_wakeup = serport_ldisc_write_wakeup
246};
247
248/*
249 * The functions for insering/removing us as a module.
250 */
251
252static int __init serport_init(void)
253{
254 int retval;
255 retval = tty_register_ldisc(N_MOUSE, &serport_ldisc);
256 if (retval)
257 printk(KERN_ERR "serport.c: Error registering line discipline.\n");
258
259 return retval;
260}
261
262static void __exit serport_exit(void)
263{
Alexey Dobriyan64ccd712005-06-23 00:10:33 -0700264 tty_unregister_ldisc(N_MOUSE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265}
266
267module_init(serport_init);
268module_exit(serport_exit);