summaryrefslogtreecommitdiff
path: root/drivers/media/rc/img-ir/img-ir-nec.c
blob: e7a731bc3a9b26b0297aae0b79cd508bdaf16653 (plain)
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
/*
 * ImgTec IR Decoder setup for NEC protocol.
 *
 * Copyright 2010-2014 Imagination Technologies Ltd.
 */

#include "img-ir-hw.h"

/* Convert NEC data to a scancode */
static int img_ir_nec_scancode(int len, u64 raw, int *scancode, u64 protocols)
{
	unsigned int addr, addr_inv, data, data_inv;
	/* a repeat code has no data */
	if (!len)
		return IMG_IR_REPEATCODE;
	if (len != 32)
		return -EINVAL;
	/* raw encoding: ddDDaaAA */
	addr     = (raw >>  0) & 0xff;
	addr_inv = (raw >>  8) & 0xff;
	data     = (raw >> 16) & 0xff;
	data_inv = (raw >> 24) & 0xff;
	if ((data_inv ^ data) != 0xff) {
		/* 32-bit NEC (used by Apple and TiVo remotes) */
		/* scan encoding: aaAAddDD */
		*scancode = addr_inv << 24 |
			    addr     << 16 |
			    data_inv <<  8 |
			    data;
	} else if ((addr_inv ^ addr) != 0xff) {
		/* Extended NEC */
		/* scan encoding: AAaaDD */
		*scancode = addr     << 16 |
			    addr_inv <<  8 |
			    data;
	} else {
		/* Normal NEC */
		/* scan encoding: AADD */
		*scancode = addr << 8 |
			    data;
	}
	return IMG_IR_SCANCODE;
}

/* Convert NEC scancode to NEC data filter */
static int img_ir_nec_filter(const struct rc_scancode_filter *in,
			     struct img_ir_filter *out, u64 protocols)
{
	unsigned int addr, addr_inv, data, data_inv;
	unsigned int addr_m, addr_inv_m, data_m, data_inv_m;

	data       = in->data & 0xff;
	data_m     = in->mask & 0xff;

	if ((in->data | in->mask) & 0xff000000) {
		/* 32-bit NEC (used by Apple and TiVo remotes) */
		/* scan encoding: aaAAddDD */
		addr_inv   = (in->data >> 24) & 0xff;
		addr_inv_m = (in->mask >> 24) & 0xff;
		addr       = (in->data >> 16) & 0xff;
		addr_m     = (in->mask >> 16) & 0xff;
		data_inv   = (in->data >>  8) & 0xff;
		data_inv_m = (in->mask >>  8) & 0xff;
	} else if ((in->data | in->mask) & 0x00ff0000) {
		/* Extended NEC */
		/* scan encoding AAaaDD */
		addr       = (in->data >> 16) & 0xff;
		addr_m     = (in->mask >> 16) & 0xff;
		addr_inv   = (in->data >>  8) & 0xff;
		addr_inv_m = (in->mask >>  8) & 0xff;
		data_inv   = data ^ 0xff;
		data_inv_m = data_m;
	} else {
		/* Normal NEC */
		/* scan encoding: AADD */
		addr       = (in->data >>  8) & 0xff;
		addr_m     = (in->mask >>  8) & 0xff;
		addr_inv   = addr ^ 0xff;
		addr_inv_m = addr_m;
		data_inv   = data ^ 0xff;
		data_inv_m = data_m;
	}

	/* raw encoding: ddDDaaAA */
	out->data = data_inv << 24 |
		    data     << 16 |
		    addr_inv <<  8 |
		    addr;
	out->mask = data_inv_m << 24 |
		    data_m     << 16 |
		    addr_inv_m <<  8 |
		    addr_m;
	return 0;
}

/*
 * NEC decoder
 * See also http://www.sbprojects.com/knowledge/ir/nec.php
 *        http://wiki.altium.com/display/ADOH/NEC+Infrared+Transmission+Protocol
 */
struct img_ir_decoder img_ir_nec = {
	.type = RC_BIT_NEC,
	.control = {
		.decoden = 1,
		.code_type = IMG_IR_CODETYPE_PULSEDIST,
	},
	/* main timings */
	.unit = 562500, /* 562.5 us */
	.timings = {
		/* leader symbol */
		.ldr = {
			.pulse = { 16	/* 9ms */ },
			.space = { 8	/* 4.5ms */ },
		},
		/* 0 symbol */
		.s00 = {
			.pulse = { 1	/* 562.5 us */ },
			.space = { 1	/* 562.5 us */ },
		},
		/* 1 symbol */
		.s01 = {
			.pulse = { 1	/* 562.5 us */ },
			.space = { 3	/* 1687.5 us */ },
		},
		/* free time */
		.ft = {
			.minlen = 32,
			.maxlen = 32,
			.ft_min = 10,	/* 5.625 ms */
		},
	},
	/* repeat codes */
	.repeat = 108,			/* 108 ms */
	.rtimings = {
		/* leader symbol */
		.ldr = {
			.space = { 4	/* 2.25 ms */ },
		},
		/* free time */
		.ft = {
			.minlen = 0,	/* repeat code has no data */
			.maxlen = 0,
		},
	},
	/* scancode logic */
	.scancode = img_ir_nec_scancode,
	.filter = img_ir_nec_filter,
};