drivers/media/rc/img-ir/img-ir-rc5.c

   1 /*
   2  * ImgTec IR Decoder setup for Philips RC-5 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 RC5 data to a scancode */
  15 static int img_ir_rc5_scancode(int len, u64 raw, u64 enabled_protocols,
  16                                 struct img_ir_scancode_req *request)
  17 {
  18         unsigned int addr, cmd, tgl, start;
  19
  20         /* Quirk in the decoder shifts everything by 2 to the left. */
  21         raw   >>= 2;
  22
  23         start   =  (raw >> 13)  & 0x01;
  24         tgl     =  (raw >> 11)  & 0x01;
  25         addr    =  (raw >>  6)  & 0x1f;
  26         cmd     =   raw         & 0x3f;
  27         /*
  28          * 12th bit is used to extend the command in extended RC5 and has
  29          * no effect on standard RC5.
  30          */
  31         cmd     += ((raw >> 12) & 0x01) ? 0 : 0x40;
  32
  33         if (!start)
  34                 return -EINVAL;
  35
  36         request->protocol = RC_TYPE_RC5;
  37         request->scancode = addr << 8 | cmd;
  38         request->toggle   = tgl;
  39         return IMG_IR_SCANCODE;
  40 }
  41
  42 /* Convert RC5 scancode to RC5 data filter */
  43 static int img_ir_rc5_filter(const struct rc_scancode_filter *in,
  44                                  struct img_ir_filter *out, u64 protocols)
  45 {
  46         /* Not supported by the hw. */
  47         return -EINVAL;
  48 }
  49
  50 /*
  51  * RC-5 decoder
  52  * see http://www.sbprojects.com/knowledge/ir/rc5.php
  53  */
  54 struct img_ir_decoder img_ir_rc5 = {
  55         .type      = RC_BIT_RC5,
  56         .control   = {
  57                 .bitoriend2     = 1,
  58                 .code_type      = IMG_IR_CODETYPE_BIPHASE,
  59                 .decodend2      = 1,
  60         },
  61         /* main timings */
  62         .tolerance      = 16,
  63         .unit           = 888888, /* 1/36k*32=888.888microseconds */
  64         .timings        = {
  65                 /* 10 symbol */
  66                 .s10 = {
  67                         .pulse  = { 1 },
  68                         .space  = { 1 },
  69                 },
  70
  71                 /* 11 symbol */
  72                 .s11 = {
  73                         .pulse  = { 1 },
  74                         .space  = { 1 },
  75                 },
  76
  77                 /* free time */
  78                 .ft  = {
  79                         .minlen = 14,
  80                         .maxlen = 14,
  81                         .ft_min = 5,
  82                 },
  83         },
  84
  85         /* scancode logic */
  86         .scancode       = img_ir_rc5_scancode,
  87         .filter         = img_ir_rc5_filter,
  88 };