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1// SPDX-License-Identifier: GPL-2.0-or-later2/*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 */11static 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 length18 * Trailer bit, the header information is a bit scrambled, and the19 * 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 TrailerBit25 *26 * But what we get is:27 *28 * ModeBit2 ModeBit1 ModeBit0 TrailerBit1 TrailerBit229 *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 cannot44 * 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 */60static 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 decoder69 * see http://www.sbprojects.com/knowledge/ir/rc6.php70 */71struct 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 do83 * not work, the values described below were extracted from84 * 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