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
|
/* ir-rc5-sz-decoder.c - handle RC5 Streamzap IR Pulse/Space protocol
*
* Copyright (C) 2010 by Mauro Carvalho Chehab <mchehab@redhat.com>
* Copyright (C) 2010 by Jarod Wilson <jarod@redhat.com>
*
* 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.
*/
/*
* This code handles the 15 bit RC5-ish protocol used by the Streamzap
* PC Remote.
* It considers a carrier of 36 kHz, with a total of 15 bits, where
* the first two bits are start bits, and a third one is a filing bit
*/
#include "rc-core-priv.h"
#define RC5_SZ_NBITS 15
#define RC5_UNIT 888888 /* ns */
#define RC5_BIT_START (1 * RC5_UNIT)
#define RC5_BIT_END (1 * RC5_UNIT)
enum rc5_sz_state {
STATE_INACTIVE,
STATE_BIT_START,
STATE_BIT_END,
STATE_FINISHED,
};
/**
* ir_rc5_sz_decode() - Decode one RC-5 Streamzap 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_rc5_sz_decode(struct rc_dev *dev, struct ir_raw_event ev)
{
struct rc5_sz_dec *data = &dev->raw->rc5_sz;
u8 toggle, command, system;
u32 scancode;
if (!(dev->raw->enabled_protocols & IR_TYPE_RC5_SZ))
return 0;
if (!is_timing_event(ev)) {
if (ev.reset)
data->state = STATE_INACTIVE;
return 0;
}
if (!geq_margin(ev.duration, RC5_UNIT, RC5_UNIT / 2))
goto out;
again:
IR_dprintk(2, "RC5-sz decode started at state %i (%uus %s)\n",
data->state, TO_US(ev.duration), TO_STR(ev.pulse));
if (!geq_margin(ev.duration, RC5_UNIT, RC5_UNIT / 2))
return 0;
switch (data->state) {
case STATE_INACTIVE:
if (!ev.pulse)
break;
data->state = STATE_BIT_START;
data->count = 1;
data->wanted_bits = RC5_SZ_NBITS;
decrease_duration(&ev, RC5_BIT_START);
goto again;
case STATE_BIT_START:
if (!eq_margin(ev.duration, RC5_BIT_START, RC5_UNIT / 2))
break;
data->bits <<= 1;
if (!ev.pulse)
data->bits |= 1;
data->count++;
data->state = STATE_BIT_END;
return 0;
case STATE_BIT_END:
if (!is_transition(&ev, &dev->raw->prev_ev))
break;
if (data->count == data->wanted_bits)
data->state = STATE_FINISHED;
else
data->state = STATE_BIT_START;
decrease_duration(&ev, RC5_BIT_END);
goto again;
case STATE_FINISHED:
if (ev.pulse)
break;
/* RC5-sz */
command = (data->bits & 0x0003F) >> 0;
system = (data->bits & 0x02FC0) >> 6;
toggle = (data->bits & 0x01000) ? 1 : 0;
scancode = system << 6 | command;
IR_dprintk(1, "RC5-sz scancode 0x%04x (toggle: %u)\n",
scancode, toggle);
ir_keydown(dev, scancode, toggle);
data->state = STATE_INACTIVE;
return 0;
}
out:
IR_dprintk(1, "RC5-sz decode failed at state %i (%uus %s)\n",
data->state, TO_US(ev.duration), TO_STR(ev.pulse));
data->state = STATE_INACTIVE;
return -EINVAL;
}
static struct ir_raw_handler rc5_sz_handler = {
.protocols = IR_TYPE_RC5_SZ,
.decode = ir_rc5_sz_decode,
};
static int __init ir_rc5_sz_decode_init(void)
{
ir_raw_handler_register(&rc5_sz_handler);
printk(KERN_INFO "IR RC5 (streamzap) protocol handler initialized\n");
return 0;
}
static void __exit ir_rc5_sz_decode_exit(void)
{
ir_raw_handler_unregister(&rc5_sz_handler);
}
module_init(ir_rc5_sz_decode_init);
module_exit(ir_rc5_sz_decode_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>");
MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
MODULE_DESCRIPTION("RC5 (streamzap) IR protocol decoder");
|
