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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/input/serio/serport.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/input/serio/serport.c')
-rw-r--r--drivers/input/serio/serport.c226
1 files changed, 226 insertions, 0 deletions
diff --git a/drivers/input/serio/serport.c b/drivers/input/serio/serport.c
new file mode 100644
index 000000000000..22f73683952b
--- /dev/null
+++ b/drivers/input/serio/serport.c
@@ -0,0 +1,226 @@
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
24MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
25MODULE_DESCRIPTION("Input device TTY line discipline");
26MODULE_LICENSE("GPL");
27MODULE_ALIAS_LDISC(N_MOUSE);
28
29#define SERPORT_BUSY 1
30
31struct serport {
32 struct tty_struct *tty;
33 wait_queue_head_t wait;
34 struct serio *serio;
35 unsigned long flags;
36};
37
38/*
39 * Callback functions from the serio code.
40 */
41
42static int serport_serio_write(struct serio *serio, unsigned char data)
43{
44 struct serport *serport = serio->port_data;
45 return -(serport->tty->driver->write(serport->tty, &data, 1) != 1);
46}
47
48static void serport_serio_close(struct serio *serio)
49{
50 struct serport *serport = serio->port_data;
51
52 serport->serio->id.type = 0;
53 wake_up_interruptible(&serport->wait);
54}
55
56/*
57 * serport_ldisc_open() is the routine that is called upon setting our line
58 * discipline on a tty. It prepares the serio struct.
59 */
60
61static int serport_ldisc_open(struct tty_struct *tty)
62{
63 struct serport *serport;
64 struct serio *serio;
65 char name[64];
66
67 if (!capable(CAP_SYS_ADMIN))
68 return -EPERM;
69
70 serport = kmalloc(sizeof(struct serport), GFP_KERNEL);
71 serio = kmalloc(sizeof(struct serio), GFP_KERNEL);
72 if (unlikely(!serport || !serio)) {
73 kfree(serport);
74 kfree(serio);
75 return -ENOMEM;
76 }
77
78 memset(serport, 0, sizeof(struct serport));
79 serport->serio = serio;
80 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
81 serport->tty = tty;
82 tty->disc_data = serport;
83
84 memset(serio, 0, sizeof(struct serio));
85 strlcpy(serio->name, "Serial port", sizeof(serio->name));
86 snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", tty_name(tty, name));
87 serio->id.type = SERIO_RS232;
88 serio->write = serport_serio_write;
89 serio->close = serport_serio_close;
90 serio->port_data = serport;
91
92 init_waitqueue_head(&serport->wait);
93
94 return 0;
95}
96
97/*
98 * serport_ldisc_close() is the opposite of serport_ldisc_open()
99 */
100
101static void serport_ldisc_close(struct tty_struct *tty)
102{
103 struct serport *serport = (struct serport*) tty->disc_data;
104 kfree(serport);
105}
106
107/*
108 * serport_ldisc_receive() is called by the low level tty driver when characters
109 * are ready for us. We forward the characters, one by one to the 'interrupt'
110 * routine.
111 *
112 * FIXME: We should get pt_regs from the tty layer and forward them to
113 * serio_interrupt here.
114 */
115
116static void serport_ldisc_receive(struct tty_struct *tty, const unsigned char *cp, char *fp, int count)
117{
118 struct serport *serport = (struct serport*) tty->disc_data;
119 int i;
120 for (i = 0; i < count; i++)
121 serio_interrupt(serport->serio, cp[i], 0, NULL);
122}
123
124/*
125 * serport_ldisc_room() reports how much room we do have for receiving data.
126 * Although we in fact have infinite room, we need to specify some value
127 * here, and 256 seems to be reasonable.
128 */
129
130static int serport_ldisc_room(struct tty_struct *tty)
131{
132 return 256;
133}
134
135/*
136 * serport_ldisc_read() just waits indefinitely if everything goes well.
137 * However, when the serio driver closes the serio port, it finishes,
138 * returning 0 characters.
139 */
140
141static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, unsigned char __user * buf, size_t nr)
142{
143 struct serport *serport = (struct serport*) tty->disc_data;
144 char name[64];
145
146 if (test_and_set_bit(SERPORT_BUSY, &serport->flags))
147 return -EBUSY;
148
149 serio_register_port(serport->serio);
150 printk(KERN_INFO "serio: Serial port %s\n", tty_name(tty, name));
151 wait_event_interruptible(serport->wait, !serport->serio->id.type);
152 serio_unregister_port(serport->serio);
153
154 clear_bit(SERPORT_BUSY, &serport->flags);
155
156 return 0;
157}
158
159/*
160 * serport_ldisc_ioctl() allows to set the port protocol, and device ID
161 */
162
163static int serport_ldisc_ioctl(struct tty_struct * tty, struct file * file, unsigned int cmd, unsigned long arg)
164{
165 struct serport *serport = (struct serport*) tty->disc_data;
166 struct serio *serio = serport->serio;
167 unsigned long type;
168
169 if (cmd == SPIOCSTYPE) {
170 if (get_user(type, (unsigned long __user *) arg))
171 return -EFAULT;
172
173 serio->id.proto = type & 0x000000ff;
174 serio->id.id = (type & 0x0000ff00) >> 8;
175 serio->id.extra = (type & 0x00ff0000) >> 16;
176
177 return 0;
178 }
179
180 return -EINVAL;
181}
182
183static void serport_ldisc_write_wakeup(struct tty_struct * tty)
184{
185 struct serport *sp = (struct serport *) tty->disc_data;
186
187 serio_drv_write_wakeup(sp->serio);
188}
189
190/*
191 * The line discipline structure.
192 */
193
194static struct tty_ldisc serport_ldisc = {
195 .owner = THIS_MODULE,
196 .name = "input",
197 .open = serport_ldisc_open,
198 .close = serport_ldisc_close,
199 .read = serport_ldisc_read,
200 .ioctl = serport_ldisc_ioctl,
201 .receive_buf = serport_ldisc_receive,
202 .receive_room = serport_ldisc_room,
203 .write_wakeup = serport_ldisc_write_wakeup
204};
205
206/*
207 * The functions for insering/removing us as a module.
208 */
209
210static int __init serport_init(void)
211{
212 int retval;
213 retval = tty_register_ldisc(N_MOUSE, &serport_ldisc);
214 if (retval)
215 printk(KERN_ERR "serport.c: Error registering line discipline.\n");
216
217 return retval;
218}
219
220static void __exit serport_exit(void)
221{
222 tty_register_ldisc(N_MOUSE, NULL);
223}
224
225module_init(serport_init);
226module_exit(serport_exit);