| Sifan Naeem | cb9564e | 2014-12-11 17:06:26 -0300 | [diff] [blame] | 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 | }; |