1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * ImgTec IR Decoder setup for NEC protocol.
5 * Copyright 2010-2014 Imagination Technologies Ltd.
9 #include <linux/bitrev.h>
10 #include <linux/log2.h>
12 /* Convert NEC data to a scancode */
13 static int img_ir_nec_scancode(int len, u64 raw, u64 enabled_protocols,
14 struct img_ir_scancode_req *request)
16 unsigned int addr, addr_inv, data, data_inv;
17 /* a repeat code has no data */
19 return IMG_IR_REPEATCODE;
22 /* raw encoding: ddDDaaAA */
23 addr = (raw >> 0) & 0xff;
24 addr_inv = (raw >> 8) & 0xff;
25 data = (raw >> 16) & 0xff;
26 data_inv = (raw >> 24) & 0xff;
27 if ((data_inv ^ data) != 0xff) {
28 /* 32-bit NEC (used by Apple and TiVo remotes) */
29 /* scan encoding: as transmitted, MSBit = first received bit */
30 request->scancode = bitrev8(addr) << 24 |
31 bitrev8(addr_inv) << 16 |
34 request->protocol = RC_PROTO_NEC32;
35 } else if ((addr_inv ^ addr) != 0xff) {
37 /* scan encoding: AAaaDD */
38 request->scancode = addr << 16 |
41 request->protocol = RC_PROTO_NECX;
44 /* scan encoding: AADD */
45 request->scancode = addr << 8 |
47 request->protocol = RC_PROTO_NEC;
49 return IMG_IR_SCANCODE;
52 /* Convert NEC scancode to NEC data filter */
53 static int img_ir_nec_filter(const struct rc_scancode_filter *in,
54 struct img_ir_filter *out, u64 protocols)
56 unsigned int addr, addr_inv, data, data_inv;
57 unsigned int addr_m, addr_inv_m, data_m, data_inv_m;
59 data = in->data & 0xff;
60 data_m = in->mask & 0xff;
62 protocols &= RC_PROTO_BIT_NEC | RC_PROTO_BIT_NECX | RC_PROTO_BIT_NEC32;
65 * If only one bit is set, we were requested to do an exact
66 * protocol. This should be the case for wakeup filters; for
67 * normal filters, guess the protocol from the scancode.
69 if (!is_power_of_2(protocols)) {
70 if ((in->data | in->mask) & 0xff000000)
71 protocols = RC_PROTO_BIT_NEC32;
72 else if ((in->data | in->mask) & 0x00ff0000)
73 protocols = RC_PROTO_BIT_NECX;
75 protocols = RC_PROTO_BIT_NEC;
78 if (protocols == RC_PROTO_BIT_NEC32) {
79 /* 32-bit NEC (used by Apple and TiVo remotes) */
80 /* scan encoding: as transmitted, MSBit = first received bit */
81 addr = bitrev8(in->data >> 24);
82 addr_m = bitrev8(in->mask >> 24);
83 addr_inv = bitrev8(in->data >> 16);
84 addr_inv_m = bitrev8(in->mask >> 16);
85 data = bitrev8(in->data >> 8);
86 data_m = bitrev8(in->mask >> 8);
87 data_inv = bitrev8(in->data >> 0);
88 data_inv_m = bitrev8(in->mask >> 0);
89 } else if (protocols == RC_PROTO_BIT_NECX) {
91 /* scan encoding AAaaDD */
92 addr = (in->data >> 16) & 0xff;
93 addr_m = (in->mask >> 16) & 0xff;
94 addr_inv = (in->data >> 8) & 0xff;
95 addr_inv_m = (in->mask >> 8) & 0xff;
96 data_inv = data ^ 0xff;
100 /* scan encoding: AADD */
101 addr = (in->data >> 8) & 0xff;
102 addr_m = (in->mask >> 8) & 0xff;
103 addr_inv = addr ^ 0xff;
105 data_inv = data ^ 0xff;
109 /* raw encoding: ddDDaaAA */
110 out->data = data_inv << 24 |
114 out->mask = data_inv_m << 24 |
123 * See also http://www.sbprojects.com/knowledge/ir/nec.php
124 * http://wiki.altium.com/display/ADOH/NEC+Infrared+Transmission+Protocol
126 struct img_ir_decoder img_ir_nec = {
127 .type = RC_PROTO_BIT_NEC | RC_PROTO_BIT_NECX | RC_PROTO_BIT_NEC32,
130 .code_type = IMG_IR_CODETYPE_PULSEDIST,
133 .unit = 562500, /* 562.5 us */
137 .pulse = { 16 /* 9ms */ },
138 .space = { 8 /* 4.5ms */ },
142 .pulse = { 1 /* 562.5 us */ },
143 .space = { 1 /* 562.5 us */ },
147 .pulse = { 1 /* 562.5 us */ },
148 .space = { 3 /* 1687.5 us */ },
154 .ft_min = 10, /* 5.625 ms */
158 .repeat = 108, /* 108 ms */
162 .space = { 4 /* 2.25 ms */ },
166 .minlen = 0, /* repeat code has no data */
171 .scancode = img_ir_nec_scancode,
172 .filter = img_ir_nec_filter,