1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * ImgTec IR Decoder setup for Philips RC-6 protocol. 4 * 5 * Copyright 2012-2014 Imagination Technologies Ltd. 6 */ 7 8 #include "img-ir-hw.h" 9 10 /* Convert RC6 data to a scancode */ 11 static int img_ir_rc6_scancode(int len, u64 raw, u64 enabled_protocols, 12 struct img_ir_scancode_req *request) 13 { 14 unsigned int addr, cmd, mode, trl1, trl2; 15 16 /* 17 * Due to a side effect of the decoder handling the double length 18 * Trailer bit, the header information is a bit scrambled, and the 19 * raw data is shifted incorrectly. 20 * This workaround effectively recovers the header bits. 21 * 22 * The Header field should look like this: 23 * 24 * StartBit ModeBit2 ModeBit1 ModeBit0 TrailerBit 25 * 26 * But what we get is: 27 * 28 * ModeBit2 ModeBit1 ModeBit0 TrailerBit1 TrailerBit2 29 * 30 * The start bit is not important to recover the scancode. 31 */ 32 33 raw >>= 27; 34 35 trl1 = (raw >> 17) & 0x01; 36 trl2 = (raw >> 16) & 0x01; 37 38 mode = (raw >> 18) & 0x07; 39 addr = (raw >> 8) & 0xff; 40 cmd = raw & 0xff; 41 42 /* 43 * Due to the above explained irregularity the trailer bits cannot 44 * have the same value. 45 */ 46 if (trl1 == trl2) 47 return -EINVAL; 48 49 /* Only mode 0 supported for now */ 50 if (mode) 51 return -EINVAL; 52 53 request->protocol = RC_PROTO_RC6_0; 54 request->scancode = addr << 8 | cmd; 55 request->toggle = trl2; 56 return IMG_IR_SCANCODE; 57 } 58 59 /* Convert RC6 scancode to RC6 data filter */ 60 static int img_ir_rc6_filter(const struct rc_scancode_filter *in, 61 struct img_ir_filter *out, u64 protocols) 62 { 63 /* Not supported by the hw. */ 64 return -EINVAL; 65 } 66 67 /* 68 * RC-6 decoder 69 * see http://www.sbprojects.com/knowledge/ir/rc6.php 70 */ 71 struct img_ir_decoder img_ir_rc6 = { 72 .type = RC_PROTO_BIT_RC6_0, 73 .control = { 74 .bitorien = 1, 75 .code_type = IMG_IR_CODETYPE_BIPHASE, 76 .decoden = 1, 77 .decodinpol = 1, 78 }, 79 /* main timings */ 80 .tolerance = 20, 81 /* 82 * Due to a quirk in the img-ir decoder, default header values do 83 * not work, the values described below were extracted from 84 * successful RTL test cases. 85 */ 86 .timings = { 87 /* leader symbol */ 88 .ldr = { 89 .pulse = { 650 }, 90 .space = { 660 }, 91 }, 92 /* 0 symbol */ 93 .s00 = { 94 .pulse = { 370 }, 95 .space = { 370 }, 96 }, 97 /* 01 symbol */ 98 .s01 = { 99 .pulse = { 370 }, 100 .space = { 370 }, 101 }, 102 /* free time */ 103 .ft = { 104 .minlen = 21, 105 .maxlen = 21, 106 .ft_min = 2666, /* 2.666 ms */ 107 }, 108 }, 109 110 /* scancode logic */ 111 .scancode = img_ir_rc6_scancode, 112 .filter = img_ir_rc6_filter, 113 }; 114