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 */ 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 */ 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