1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
/*
* Parallel port to Keyboard port adapter driver for Linux
*
* Copyright (c) 1999-2004 Vojtech Pavlik
*/
/*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*/
/*
* To connect an AT or XT keyboard to the parallel port, a fairly simple adapter
* can be made:
*
* Parallel port Keyboard port
*
* +5V --------------------- +5V (4)
*
* ______
* +5V -------|______|--.
* |
* ACK (10) ------------|
* |--- KBD CLOCK (5)
* STROBE (1) ---|<|----'
*
* ______
* +5V -------|______|--.
* |
* BUSY (11) -----------|
* |--- KBD DATA (1)
* AUTOFD (14) --|<|----'
*
* GND (18-25) ------------- GND (3)
*
* The diodes can be fairly any type, and the resistors should be somewhere
* around 5 kOhm, but the adapter will likely work without the resistors,
* too.
*
* The +5V source can be taken either from USB, from mouse or keyboard ports,
* or from a joystick port. Unfortunately, the parallel port of a PC doesn't
* have a +5V pin, and feeding the keyboard from signal pins is out of question
* with 300 mA power reqirement of a typical AT keyboard.
*/
#include <linux/module.h>
#include <linux/parport.h>
#include <linux/init.h>
#include <linux/serio.h>
MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
MODULE_DESCRIPTION("Parallel port to Keyboard port adapter driver");
MODULE_LICENSE("GPL");
static unsigned int parkbd_pp_no;
module_param_named(port, parkbd_pp_no, int, 0);
MODULE_PARM_DESC(port, "Parallel port the adapter is connected to (default is 0)");
static unsigned int parkbd_mode = SERIO_8042;
module_param_named(mode, parkbd_mode, uint, 0);
MODULE_PARM_DESC(mode, "Mode of operation: XT = 0/AT = 1 (default)");
#define PARKBD_CLOCK 0x01 /* Strobe & Ack */
#define PARKBD_DATA 0x02 /* AutoFd & Busy */
static int parkbd_buffer;
static int parkbd_counter;
static unsigned long parkbd_last;
static int parkbd_writing;
static unsigned long parkbd_start;
static struct pardevice *parkbd_dev;
static struct serio *parkbd_port;
static int parkbd_readlines(void)
{
return (parport_read_status(parkbd_dev->port) >> 6) ^ 2;
}
static void parkbd_writelines(int data)
{
parport_write_control(parkbd_dev->port, (~data & 3) | 0x10);
}
static int parkbd_write(struct serio *port, unsigned char c)
{
unsigned char p;
if (!parkbd_mode) return -1;
p = c ^ (c >> 4);
p = p ^ (p >> 2);
p = p ^ (p >> 1);
parkbd_counter = 0;
parkbd_writing = 1;
parkbd_buffer = c | (((int) (~p & 1)) << 8) | 0x600;
parkbd_writelines(2);
return 0;
}
static void parkbd_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
if (parkbd_writing) {
if (parkbd_counter && ((parkbd_counter == 11) || time_after(jiffies, parkbd_last + HZ/100))) {
parkbd_counter = 0;
parkbd_buffer = 0;
parkbd_writing = 0;
parkbd_writelines(3);
return;
}
parkbd_writelines(((parkbd_buffer >> parkbd_counter++) & 1) | 2);
if (parkbd_counter == 11) {
parkbd_counter = 0;
parkbd_buffer = 0;
parkbd_writing = 0;
parkbd_writelines(3);
}
} else {
if ((parkbd_counter == parkbd_mode + 10) || time_after(jiffies, parkbd_last + HZ/100)) {
parkbd_counter = 0;
parkbd_buffer = 0;
}
parkbd_buffer |= (parkbd_readlines() >> 1) << parkbd_counter++;
if (parkbd_counter == parkbd_mode + 10)
serio_interrupt(parkbd_port, (parkbd_buffer >> (2 - parkbd_mode)) & 0xff, 0, regs);
}
parkbd_last = jiffies;
}
static int parkbd_getport(void)
{
struct parport *pp;
pp = parport_find_number(parkbd_pp_no);
if (pp == NULL) {
printk(KERN_ERR "parkbd: no such parport\n");
return -ENODEV;
}
parkbd_dev = parport_register_device(pp, "parkbd", NULL, NULL, parkbd_interrupt, PARPORT_DEV_EXCL, NULL);
parport_put_port(pp);
if (!parkbd_dev)
return -ENODEV;
if (parport_claim(parkbd_dev)) {
parport_unregister_device(parkbd_dev);
return -EBUSY;
}
parkbd_start = jiffies;
return 0;
}
static struct serio * __init parkbd_allocate_serio(void)
{
struct serio *serio;
serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
if (serio) {
serio->id.type = parkbd_mode;
serio->write = parkbd_write,
strlcpy(serio->name, "PARKBD AT/XT keyboard adapter", sizeof(serio->name));
snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", parkbd_dev->port->name);
}
return serio;
}
static int __init parkbd_init(void)
{
int err;
err = parkbd_getport();
if (err)
return err;
parkbd_port = parkbd_allocate_serio();
if (!parkbd_port) {
parport_release(parkbd_dev);
return -ENOMEM;
}
parkbd_writelines(3);
serio_register_port(parkbd_port);
printk(KERN_INFO "serio: PARKBD %s adapter on %s\n",
parkbd_mode ? "AT" : "XT", parkbd_dev->port->name);
return 0;
}
static void __exit parkbd_exit(void)
{
parport_release(parkbd_dev);
serio_unregister_port(parkbd_port);
parport_unregister_device(parkbd_dev);
}
module_init(parkbd_init);
module_exit(parkbd_exit);
|
