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
218
219
220
221
222
223
224
|
/* ir-xmp-decoder.c - handle XMP IR Pulse/Space protocol
*
* Copyright (C) 2014 by Marcel Mol
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* - Based on info from http://www.hifi-remote.com
* - Ignore Toggle=9 frames
* - Ignore XMP-1 XMP-2 difference, always store 16 bit OBC
*/
#include <linux/bitrev.h>
#include <linux/module.h>
#include "rc-core-priv.h"
#define XMP_UNIT 136000 /* ns */
#define XMP_LEADER 210000 /* ns */
#define XMP_NIBBLE_PREFIX 760000 /* ns */
#define XMP_HALFFRAME_SPACE 13800000 /* ns */
#define XMP_TRAILER_SPACE 20000000 /* should be 80ms but not all dureation supliers can go that high */
enum xmp_state {
STATE_INACTIVE,
STATE_LEADER_PULSE,
STATE_NIBBLE_SPACE,
};
/**
* ir_xmp_decode() - Decode one XMP pulse or space
* @dev: the struct rc_dev descriptor of the device
* @ev: the struct ir_raw_event descriptor of the pulse/space
*
* This function returns -EINVAL if the pulse violates the state machine
*/
static int ir_xmp_decode(struct rc_dev *dev, struct ir_raw_event ev)
{
struct xmp_dec *data = &dev->raw->xmp;
if (!is_timing_event(ev)) {
if (ev.reset)
data->state = STATE_INACTIVE;
return 0;
}
dev_dbg(&dev->dev, "XMP decode started at state %d %d (%uus %s)\n",
data->state, data->count, TO_US(ev.duration), TO_STR(ev.pulse));
switch (data->state) {
case STATE_INACTIVE:
if (!ev.pulse)
break;
if (eq_margin(ev.duration, XMP_LEADER, XMP_UNIT / 2)) {
data->count = 0;
data->state = STATE_NIBBLE_SPACE;
}
return 0;
case STATE_LEADER_PULSE:
if (!ev.pulse)
break;
if (eq_margin(ev.duration, XMP_LEADER, XMP_UNIT / 2))
data->state = STATE_NIBBLE_SPACE;
return 0;
case STATE_NIBBLE_SPACE:
if (ev.pulse)
break;
if (geq_margin(ev.duration, XMP_TRAILER_SPACE, XMP_NIBBLE_PREFIX)) {
int divider, i;
u8 addr, subaddr, subaddr2, toggle, oem, obc1, obc2, sum1, sum2;
u32 *n;
u32 scancode;
if (data->count != 16) {
dev_dbg(&dev->dev, "received TRAILER period at index %d: %u\n",
data->count, ev.duration);
data->state = STATE_INACTIVE;
return -EINVAL;
}
n = data->durations;
/*
* the 4th nibble should be 15 so base the divider on this
* to transform durations into nibbles. Substract 2000 from
* the divider to compensate for fluctuations in the signal
*/
divider = (n[3] - XMP_NIBBLE_PREFIX) / 15 - 2000;
if (divider < 50) {
dev_dbg(&dev->dev, "divider to small %d.\n",
divider);
data->state = STATE_INACTIVE;
return -EINVAL;
}
/* convert to nibbles and do some sanity checks */
for (i = 0; i < 16; i++)
n[i] = (n[i] - XMP_NIBBLE_PREFIX) / divider;
sum1 = (15 + n[0] + n[1] + n[2] + n[3] +
n[4] + n[5] + n[6] + n[7]) % 16;
sum2 = (15 + n[8] + n[9] + n[10] + n[11] +
n[12] + n[13] + n[14] + n[15]) % 16;
if (sum1 != 15 || sum2 != 15) {
dev_dbg(&dev->dev, "checksum errors sum1=0x%X sum2=0x%X\n",
sum1, sum2);
data->state = STATE_INACTIVE;
return -EINVAL;
}
subaddr = n[0] << 4 | n[2];
subaddr2 = n[8] << 4 | n[11];
oem = n[4] << 4 | n[5];
addr = n[6] << 4 | n[7];
toggle = n[10];
obc1 = n[12] << 4 | n[13];
obc2 = n[14] << 4 | n[15];
if (subaddr != subaddr2) {
dev_dbg(&dev->dev, "subaddress nibbles mismatch 0x%02X != 0x%02X\n",
subaddr, subaddr2);
data->state = STATE_INACTIVE;
return -EINVAL;
}
if (oem != 0x44)
dev_dbg(&dev->dev, "Warning: OEM nibbles 0x%02X. Expected 0x44\n",
oem);
scancode = addr << 24 | subaddr << 16 |
obc1 << 8 | obc2;
dev_dbg(&dev->dev, "XMP scancode 0x%06x\n", scancode);
if (toggle == 0) {
rc_keydown(dev, RC_PROTO_XMP, scancode, 0);
} else {
rc_repeat(dev);
dev_dbg(&dev->dev, "Repeat last key\n");
}
data->state = STATE_INACTIVE;
return 0;
} else if (geq_margin(ev.duration, XMP_HALFFRAME_SPACE, XMP_NIBBLE_PREFIX)) {
/* Expect 8 or 16 nibble pulses. 16 in case of 'final' frame */
if (data->count == 16) {
dev_dbg(&dev->dev, "received half frame pulse at index %d. Probably a final frame key-up event: %u\n",
data->count, ev.duration);
/*
* TODO: for now go back to half frame position
* so trailer can be found and key press
* can be handled.
*/
data->count = 8;
}
else if (data->count != 8)
dev_dbg(&dev->dev, "received half frame pulse at index %d: %u\n",
data->count, ev.duration);
data->state = STATE_LEADER_PULSE;
return 0;
} else if (geq_margin(ev.duration, XMP_NIBBLE_PREFIX, XMP_UNIT)) {
/* store nibble raw data, decode after trailer */
if (data->count == 16) {
dev_dbg(&dev->dev, "to many pulses (%d) ignoring: %u\n",
data->count, ev.duration);
data->state = STATE_INACTIVE;
return -EINVAL;
}
data->durations[data->count] = ev.duration;
data->count++;
data->state = STATE_LEADER_PULSE;
return 0;
}
break;
}
dev_dbg(&dev->dev, "XMP decode failed at count %d state %d (%uus %s)\n",
data->count, data->state, TO_US(ev.duration), TO_STR(ev.pulse));
data->state = STATE_INACTIVE;
return -EINVAL;
}
static struct ir_raw_handler xmp_handler = {
.protocols = RC_PROTO_BIT_XMP,
.decode = ir_xmp_decode,
.min_timeout = XMP_TRAILER_SPACE,
};
static int __init ir_xmp_decode_init(void)
{
ir_raw_handler_register(&xmp_handler);
printk(KERN_INFO "IR XMP protocol handler initialized\n");
return 0;
}
static void __exit ir_xmp_decode_exit(void)
{
ir_raw_handler_unregister(&xmp_handler);
}
module_init(ir_xmp_decode_init);
module_exit(ir_xmp_decode_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marcel Mol <marcel@mesa.nl>");
MODULE_AUTHOR("MESA Consulting (http://www.mesa.nl)");
MODULE_DESCRIPTION("XMP IR protocol decoder");
|
