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

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * ImgTec IR Decoder setup for Philips RC-5 protocol.
   4  *
   5  * Copyright 2012-2014 Imagination Technologies Ltd.
   6  */
   7
   8 #include "img-ir-hw.h"
   9
  10 /* Convert RC5 data to a scancode */
  11 static int img_ir_rc5_scancode(int len, u64 raw, u64 enabled_protocols,
  12                                 struct img_ir_scancode_req *request)
  13 {
  14         unsigned int addr, cmd, tgl, start;
  15
  16         /* Quirk in the decoder shifts everything by 2 to the left. */
  17         raw   >>= 2;
  18
  19         start   =  (raw >> 13)  & 0x01;
  20         tgl     =  (raw >> 11)  & 0x01;
  21         addr    =  (raw >>  6)  & 0x1f;
  22         cmd     =   raw         & 0x3f;
  23         /*
  24          * 12th bit is used to extend the command in extended RC5 and has
  25          * no effect on standard RC5.
  26          */
  27         cmd     += ((raw >> 12) & 0x01) ? 0 : 0x40;
  28
  29         if (!start)
  30                 return -EINVAL;
  31
  32         request->protocol = RC_PROTO_RC5;
  33         request->scancode = addr << 8 | cmd;
  34         request->toggle   = tgl;
  35         return IMG_IR_SCANCODE;
  36 }
  37
  38 /* Convert RC5 scancode to RC5 data filter */
  39 static int img_ir_rc5_filter(const struct rc_scancode_filter *in,
  40                                  struct img_ir_filter *out, u64 protocols)
  41 {
  42         /* Not supported by the hw. */
  43         return -EINVAL;
  44 }
  45
  46 /*
  47  * RC-5 decoder
  48  * see http://www.sbprojects.com/knowledge/ir/rc5.php
  49  */
  50 struct img_ir_decoder img_ir_rc5 = {
  51         .type      = RC_PROTO_BIT_RC5,
  52         .control   = {
  53                 .bitoriend2     = 1,
  54                 .code_type      = IMG_IR_CODETYPE_BIPHASE,
  55                 .decodend2      = 1,
  56         },
  57         /* main timings */
  58         .tolerance      = 16,
  59         .unit           = 888888, /* 1/36k*32=888.888microseconds */
  60         .timings        = {
  61                 /* 10 symbol */
  62                 .s10 = {
  63                         .pulse  = { 1 },
  64                         .space  = { 1 },
  65                 },
  66
  67                 /* 11 symbol */
  68                 .s11 = {
  69                         .pulse  = { 1 },
  70                         .space  = { 1 },
  71                 },
  72
  73                 /* free time */
  74                 .ft  = {
  75                         .minlen = 14,
  76                         .maxlen = 14,
  77                         .ft_min = 5,
  78                 },
  79         },
  80
  81         /* scancode logic */
  82         .scancode       = img_ir_rc5_scancode,
  83         .filter         = img_ir_rc5_filter,
  84 };