1 /*
2 * ImgTec IR Decoder setup for NEC protocol.
3 *
4 * Copyright 2010-2014 Imagination Technologies Ltd.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version.
10 */
11
12 #include "img-ir-hw.h"
13 #include <linux/bitrev.h>
14 #include <linux/log2.h>
15
16 /* Convert NEC data to a scancode */
img_ir_nec_scancode(int len,u64 raw,u64 enabled_protocols,struct img_ir_scancode_req * request)17 static int img_ir_nec_scancode(int len, u64 raw, u64 enabled_protocols,
18 struct img_ir_scancode_req *request)
19 {
20 unsigned int addr, addr_inv, data, data_inv;
21 /* a repeat code has no data */
22 if (!len)
23 return IMG_IR_REPEATCODE;
24 if (len != 32)
25 return -EINVAL;
26 /* raw encoding: ddDDaaAA */
27 addr = (raw >> 0) & 0xff;
28 addr_inv = (raw >> 8) & 0xff;
29 data = (raw >> 16) & 0xff;
30 data_inv = (raw >> 24) & 0xff;
31 if ((data_inv ^ data) != 0xff) {
32 /* 32-bit NEC (used by Apple and TiVo remotes) */
33 /* scan encoding: as transmitted, MSBit = first received bit */
34 request->scancode = bitrev8(addr) << 24 |
35 bitrev8(addr_inv) << 16 |
36 bitrev8(data) << 8 |
37 bitrev8(data_inv);
38 request->protocol = RC_PROTO_NEC32;
39 } else if ((addr_inv ^ addr) != 0xff) {
40 /* Extended NEC */
41 /* scan encoding: AAaaDD */
42 request->scancode = addr << 16 |
43 addr_inv << 8 |
44 data;
45 request->protocol = RC_PROTO_NECX;
46 } else {
47 /* Normal NEC */
48 /* scan encoding: AADD */
49 request->scancode = addr << 8 |
50 data;
51 request->protocol = RC_PROTO_NEC;
52 }
53 return IMG_IR_SCANCODE;
54 }
55
56 /* Convert NEC scancode to NEC data filter */
img_ir_nec_filter(const struct rc_scancode_filter * in,struct img_ir_filter * out,u64 protocols)57 static int img_ir_nec_filter(const struct rc_scancode_filter *in,
58 struct img_ir_filter *out, u64 protocols)
59 {
60 unsigned int addr, addr_inv, data, data_inv;
61 unsigned int addr_m, addr_inv_m, data_m, data_inv_m;
62
63 data = in->data & 0xff;
64 data_m = in->mask & 0xff;
65
66 protocols &= RC_PROTO_BIT_NEC | RC_PROTO_BIT_NECX | RC_PROTO_BIT_NEC32;
67
68 /*
69 * If only one bit is set, we were requested to do an exact
70 * protocol. This should be the case for wakeup filters; for
71 * normal filters, guess the protocol from the scancode.
72 */
73 if (!is_power_of_2(protocols)) {
74 if ((in->data | in->mask) & 0xff000000)
75 protocols = RC_PROTO_BIT_NEC32;
76 else if ((in->data | in->mask) & 0x00ff0000)
77 protocols = RC_PROTO_BIT_NECX;
78 else
79 protocols = RC_PROTO_BIT_NEC;
80 }
81
82 if (protocols == RC_PROTO_BIT_NEC32) {
83 /* 32-bit NEC (used by Apple and TiVo remotes) */
84 /* scan encoding: as transmitted, MSBit = first received bit */
85 addr = bitrev8(in->data >> 24);
86 addr_m = bitrev8(in->mask >> 24);
87 addr_inv = bitrev8(in->data >> 16);
88 addr_inv_m = bitrev8(in->mask >> 16);
89 data = bitrev8(in->data >> 8);
90 data_m = bitrev8(in->mask >> 8);
91 data_inv = bitrev8(in->data >> 0);
92 data_inv_m = bitrev8(in->mask >> 0);
93 } else if (protocols == RC_PROTO_BIT_NECX) {
94 /* Extended NEC */
95 /* scan encoding AAaaDD */
96 addr = (in->data >> 16) & 0xff;
97 addr_m = (in->mask >> 16) & 0xff;
98 addr_inv = (in->data >> 8) & 0xff;
99 addr_inv_m = (in->mask >> 8) & 0xff;
100 data_inv = data ^ 0xff;
101 data_inv_m = data_m;
102 } else {
103 /* Normal NEC */
104 /* scan encoding: AADD */
105 addr = (in->data >> 8) & 0xff;
106 addr_m = (in->mask >> 8) & 0xff;
107 addr_inv = addr ^ 0xff;
108 addr_inv_m = addr_m;
109 data_inv = data ^ 0xff;
110 data_inv_m = data_m;
111 }
112
113 /* raw encoding: ddDDaaAA */
114 out->data = data_inv << 24 |
115 data << 16 |
116 addr_inv << 8 |
117 addr;
118 out->mask = data_inv_m << 24 |
119 data_m << 16 |
120 addr_inv_m << 8 |
121 addr_m;
122 return 0;
123 }
124
125 /*
126 * NEC decoder
127 * See also http://www.sbprojects.com/knowledge/ir/nec.php
128 * http://wiki.altium.com/display/ADOH/NEC+Infrared+Transmission+Protocol
129 */
130 struct img_ir_decoder img_ir_nec = {
131 .type = RC_PROTO_BIT_NEC | RC_PROTO_BIT_NECX | RC_PROTO_BIT_NEC32,
132 .control = {
133 .decoden = 1,
134 .code_type = IMG_IR_CODETYPE_PULSEDIST,
135 },
136 /* main timings */
137 .unit = 562500, /* 562.5 us */
138 .timings = {
139 /* leader symbol */
140 .ldr = {
141 .pulse = { 16 /* 9ms */ },
142 .space = { 8 /* 4.5ms */ },
143 },
144 /* 0 symbol */
145 .s00 = {
146 .pulse = { 1 /* 562.5 us */ },
147 .space = { 1 /* 562.5 us */ },
148 },
149 /* 1 symbol */
150 .s01 = {
151 .pulse = { 1 /* 562.5 us */ },
152 .space = { 3 /* 1687.5 us */ },
153 },
154 /* free time */
155 .ft = {
156 .minlen = 32,
157 .maxlen = 32,
158 .ft_min = 10, /* 5.625 ms */
159 },
160 },
161 /* repeat codes */
162 .repeat = 108, /* 108 ms */
163 .rtimings = {
164 /* leader symbol */
165 .ldr = {
166 .space = { 4 /* 2.25 ms */ },
167 },
168 /* free time */
169 .ft = {
170 .minlen = 0, /* repeat code has no data */
171 .maxlen = 0,
172 },
173 },
174 /* scancode logic */
175 .scancode = img_ir_nec_scancode,
176 .filter = img_ir_nec_filter,
177 };
178