1 /* 2 * ImgTec IR Decoder setup for Philips RC-6 protocol. 3 * 4 * Copyright 2012-2014 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 14 /* Convert RC6 data to a scancode */ 15 static int img_ir_rc6_scancode(int len, u64 raw, u64 enabled_protocols, 16 struct img_ir_scancode_req *request) 17 { 18 unsigned int addr, cmd, mode, trl1, trl2; 19 20 /* 21 * Due to a side effect of the decoder handling the double length 22 * Trailer bit, the header information is a bit scrambled, and the 23 * raw data is shifted incorrectly. 24 * This workaround effectively recovers the header bits. 25 * 26 * The Header field should look like this: 27 * 28 * StartBit ModeBit2 ModeBit1 ModeBit0 TrailerBit 29 * 30 * But what we get is: 31 * 32 * ModeBit2 ModeBit1 ModeBit0 TrailerBit1 TrailerBit2 33 * 34 * The start bit is not important to recover the scancode. 35 */ 36 37 raw >>= 27; 38 39 trl1 = (raw >> 17) & 0x01; 40 trl2 = (raw >> 16) & 0x01; 41 42 mode = (raw >> 18) & 0x07; 43 addr = (raw >> 8) & 0xff; 44 cmd = raw & 0xff; 45 46 /* 47 * Due to the above explained irregularity the trailer bits cannot 48 * have the same value. 49 */ 50 if (trl1 == trl2) 51 return -EINVAL; 52 53 /* Only mode 0 supported for now */ 54 if (mode) 55 return -EINVAL; 56 57 request->protocol = RC_TYPE_RC6_0; 58 request->scancode = addr << 8 | cmd; 59 request->toggle = trl2; 60 return IMG_IR_SCANCODE; 61 } 62 63 /* Convert RC6 scancode to RC6 data filter */ 64 static int img_ir_rc6_filter(const struct rc_scancode_filter *in, 65 struct img_ir_filter *out, u64 protocols) 66 { 67 /* Not supported by the hw. */ 68 return -EINVAL; 69 } 70 71 /* 72 * RC-6 decoder 73 * see http://www.sbprojects.com/knowledge/ir/rc6.php 74 */ 75 struct img_ir_decoder img_ir_rc6 = { 76 .type = RC_BIT_RC6_0, 77 .control = { 78 .bitorien = 1, 79 .code_type = IMG_IR_CODETYPE_BIPHASE, 80 .decoden = 1, 81 .decodinpol = 1, 82 }, 83 /* main timings */ 84 .tolerance = 20, 85 /* 86 * Due to a quirk in the img-ir decoder, default header values do 87 * not work, the values described below were extracted from 88 * successful RTL test cases. 89 */ 90 .timings = { 91 /* leader symbol */ 92 .ldr = { 93 .pulse = { 650 }, 94 .space = { 660 }, 95 }, 96 /* 0 symbol */ 97 .s00 = { 98 .pulse = { 370 }, 99 .space = { 370 }, 100 }, 101 /* 01 symbol */ 102 .s01 = { 103 .pulse = { 370 }, 104 .space = { 370 }, 105 }, 106 /* free time */ 107 .ft = { 108 .minlen = 21, 109 .maxlen = 21, 110 .ft_min = 2666, /* 2.666 ms */ 111 }, 112 }, 113 114 /* scancode logic */ 115 .scancode = img_ir_rc6_scancode, 116 .filter = img_ir_rc6_filter, 117 }; 118