1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * ImgTec IR Decoder setup for NEC protocol. |
4 | * |
5 | * Copyright 2010-2014 Imagination Technologies Ltd. |
6 | */ |
7 | |
8 | #include "img-ir-hw.h" |
9 | #include <linux/bitrev.h> |
10 | #include <linux/log2.h> |
11 | |
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) |
15 | { |
16 | unsigned int addr, addr_inv, data, data_inv; |
17 | /* a repeat code has no data */ |
18 | if (!len) |
19 | return IMG_IR_REPEATCODE; |
20 | if (len != 32) |
21 | return -EINVAL; |
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 | |
32 | bitrev8(data) << 8 | |
33 | bitrev8(data_inv); |
34 | request->protocol = RC_PROTO_NEC32; |
35 | } else if ((addr_inv ^ addr) != 0xff) { |
36 | /* Extended NEC */ |
37 | /* scan encoding: AAaaDD */ |
38 | request->scancode = addr << 16 | |
39 | addr_inv << 8 | |
40 | data; |
41 | request->protocol = RC_PROTO_NECX; |
42 | } else { |
43 | /* Normal NEC */ |
44 | /* scan encoding: AADD */ |
45 | request->scancode = addr << 8 | |
46 | data; |
47 | request->protocol = RC_PROTO_NEC; |
48 | } |
49 | return IMG_IR_SCANCODE; |
50 | } |
51 | |
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) |
55 | { |
56 | unsigned int addr, addr_inv, data, data_inv; |
57 | unsigned int addr_m, addr_inv_m, data_m, data_inv_m; |
58 | |
59 | data = in->data & 0xff; |
60 | data_m = in->mask & 0xff; |
61 | |
62 | protocols &= RC_PROTO_BIT_NEC | RC_PROTO_BIT_NECX | RC_PROTO_BIT_NEC32; |
63 | |
64 | /* |
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. |
68 | */ |
69 | if (!is_power_of_2(n: 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; |
74 | else |
75 | protocols = RC_PROTO_BIT_NEC; |
76 | } |
77 | |
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) { |
90 | /* Extended NEC */ |
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; |
97 | data_inv_m = data_m; |
98 | } else { |
99 | /* Normal NEC */ |
100 | /* scan encoding: AADD */ |
101 | addr = (in->data >> 8) & 0xff; |
102 | addr_m = (in->mask >> 8) & 0xff; |
103 | addr_inv = addr ^ 0xff; |
104 | addr_inv_m = addr_m; |
105 | data_inv = data ^ 0xff; |
106 | data_inv_m = data_m; |
107 | } |
108 | |
109 | /* raw encoding: ddDDaaAA */ |
110 | out->data = data_inv << 24 | |
111 | data << 16 | |
112 | addr_inv << 8 | |
113 | addr; |
114 | out->mask = data_inv_m << 24 | |
115 | data_m << 16 | |
116 | addr_inv_m << 8 | |
117 | addr_m; |
118 | return 0; |
119 | } |
120 | |
121 | /* |
122 | * NEC decoder |
123 | * See also http://www.sbprojects.com/knowledge/ir/nec.php |
124 | * http://wiki.altium.com/display/ADOH/NEC+Infrared+Transmission+Protocol |
125 | */ |
126 | struct img_ir_decoder img_ir_nec = { |
127 | .type = RC_PROTO_BIT_NEC | RC_PROTO_BIT_NECX | RC_PROTO_BIT_NEC32, |
128 | .control = { |
129 | .decoden = 1, |
130 | .code_type = IMG_IR_CODETYPE_PULSEDIST, |
131 | }, |
132 | /* main timings */ |
133 | .unit = 562500, /* 562.5 us */ |
134 | .timings = { |
135 | /* leader symbol */ |
136 | .ldr = { |
137 | .pulse = { 16 /* 9ms */ }, |
138 | .space = { 8 /* 4.5ms */ }, |
139 | }, |
140 | /* 0 symbol */ |
141 | .s00 = { |
142 | .pulse = { 1 /* 562.5 us */ }, |
143 | .space = { 1 /* 562.5 us */ }, |
144 | }, |
145 | /* 1 symbol */ |
146 | .s01 = { |
147 | .pulse = { 1 /* 562.5 us */ }, |
148 | .space = { 3 /* 1687.5 us */ }, |
149 | }, |
150 | /* free time */ |
151 | .ft = { |
152 | .minlen = 32, |
153 | .maxlen = 32, |
154 | .ft_min = 10, /* 5.625 ms */ |
155 | }, |
156 | }, |
157 | /* repeat codes */ |
158 | .repeat = 108, /* 108 ms */ |
159 | .rtimings = { |
160 | /* leader symbol */ |
161 | .ldr = { |
162 | .space = { 4 /* 2.25 ms */ }, |
163 | }, |
164 | /* free time */ |
165 | .ft = { |
166 | .minlen = 0, /* repeat code has no data */ |
167 | .maxlen = 0, |
168 | }, |
169 | }, |
170 | /* scancode logic */ |
171 | .scancode = img_ir_nec_scancode, |
172 | .filter = img_ir_nec_filter, |
173 | }; |
174 | |