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 15 /* Convert NEC data to a scancode */ 16 static int img_ir_nec_scancode(int len, u64 raw, u64 enabled_protocols, 17 struct img_ir_scancode_req *request) 18 { 19 unsigned int addr, addr_inv, data, data_inv; 20 /* a repeat code has no data */ 21 if (!len) 22 return IMG_IR_REPEATCODE; 23 if (len != 32) 24 return -EINVAL; 25 /* raw encoding: ddDDaaAA */ 26 addr = (raw >> 0) & 0xff; 27 addr_inv = (raw >> 8) & 0xff; 28 data = (raw >> 16) & 0xff; 29 data_inv = (raw >> 24) & 0xff; 30 if ((data_inv ^ data) != 0xff) { 31 /* 32-bit NEC (used by Apple and TiVo remotes) */ 32 /* scan encoding: as transmitted, MSBit = first received bit */ 33 request->scancode = bitrev8(addr) << 24 | 34 bitrev8(addr_inv) << 16 | 35 bitrev8(data) << 8 | 36 bitrev8(data_inv); 37 } else if ((addr_inv ^ addr) != 0xff) { 38 /* Extended NEC */ 39 /* scan encoding: AAaaDD */ 40 request->scancode = addr << 16 | 41 addr_inv << 8 | 42 data; 43 } else { 44 /* Normal NEC */ 45 /* scan encoding: AADD */ 46 request->scancode = addr << 8 | 47 data; 48 } 49 request->protocol = RC_TYPE_NEC; 50 return IMG_IR_SCANCODE; 51 } 52 53 /* Convert NEC scancode to NEC data filter */ 54 static int img_ir_nec_filter(const struct rc_scancode_filter *in, 55 struct img_ir_filter *out, u64 protocols) 56 { 57 unsigned int addr, addr_inv, data, data_inv; 58 unsigned int addr_m, addr_inv_m, data_m, data_inv_m; 59 60 data = in->data & 0xff; 61 data_m = in->mask & 0xff; 62 63 if ((in->data | in->mask) & 0xff000000) { 64 /* 32-bit NEC (used by Apple and TiVo remotes) */ 65 /* scan encoding: as transmitted, MSBit = first received bit */ 66 addr = bitrev8(in->data >> 24); 67 addr_m = bitrev8(in->mask >> 24); 68 addr_inv = bitrev8(in->data >> 16); 69 addr_inv_m = bitrev8(in->mask >> 16); 70 data = bitrev8(in->data >> 8); 71 data_m = bitrev8(in->mask >> 8); 72 data_inv = bitrev8(in->data >> 0); 73 data_inv_m = bitrev8(in->mask >> 0); 74 } else if ((in->data | in->mask) & 0x00ff0000) { 75 /* Extended NEC */ 76 /* scan encoding AAaaDD */ 77 addr = (in->data >> 16) & 0xff; 78 addr_m = (in->mask >> 16) & 0xff; 79 addr_inv = (in->data >> 8) & 0xff; 80 addr_inv_m = (in->mask >> 8) & 0xff; 81 data_inv = data ^ 0xff; 82 data_inv_m = data_m; 83 } else { 84 /* Normal NEC */ 85 /* scan encoding: AADD */ 86 addr = (in->data >> 8) & 0xff; 87 addr_m = (in->mask >> 8) & 0xff; 88 addr_inv = addr ^ 0xff; 89 addr_inv_m = addr_m; 90 data_inv = data ^ 0xff; 91 data_inv_m = data_m; 92 } 93 94 /* raw encoding: ddDDaaAA */ 95 out->data = data_inv << 24 | 96 data << 16 | 97 addr_inv << 8 | 98 addr; 99 out->mask = data_inv_m << 24 | 100 data_m << 16 | 101 addr_inv_m << 8 | 102 addr_m; 103 return 0; 104 } 105 106 /* 107 * NEC decoder 108 * See also http://www.sbprojects.com/knowledge/ir/nec.php 109 * http://wiki.altium.com/display/ADOH/NEC+Infrared+Transmission+Protocol 110 */ 111 struct img_ir_decoder img_ir_nec = { 112 .type = RC_BIT_NEC, 113 .control = { 114 .decoden = 1, 115 .code_type = IMG_IR_CODETYPE_PULSEDIST, 116 }, 117 /* main timings */ 118 .unit = 562500, /* 562.5 us */ 119 .timings = { 120 /* leader symbol */ 121 .ldr = { 122 .pulse = { 16 /* 9ms */ }, 123 .space = { 8 /* 4.5ms */ }, 124 }, 125 /* 0 symbol */ 126 .s00 = { 127 .pulse = { 1 /* 562.5 us */ }, 128 .space = { 1 /* 562.5 us */ }, 129 }, 130 /* 1 symbol */ 131 .s01 = { 132 .pulse = { 1 /* 562.5 us */ }, 133 .space = { 3 /* 1687.5 us */ }, 134 }, 135 /* free time */ 136 .ft = { 137 .minlen = 32, 138 .maxlen = 32, 139 .ft_min = 10, /* 5.625 ms */ 140 }, 141 }, 142 /* repeat codes */ 143 .repeat = 108, /* 108 ms */ 144 .rtimings = { 145 /* leader symbol */ 146 .ldr = { 147 .space = { 4 /* 2.25 ms */ }, 148 }, 149 /* free time */ 150 .ft = { 151 .minlen = 0, /* repeat code has no data */ 152 .maxlen = 0, 153 }, 154 }, 155 /* scancode logic */ 156 .scancode = img_ir_nec_scancode, 157 .filter = img_ir_nec_filter, 158 }; 159