diff options
Diffstat (limited to 'drivers/media/rc/img-ir/img-ir-rc6.c')
-rw-r--r-- | drivers/media/rc/img-ir/img-ir-rc6.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/drivers/media/rc/img-ir/img-ir-rc6.c b/drivers/media/rc/img-ir/img-ir-rc6.c new file mode 100644 index 000000000000..de1e27534968 --- /dev/null +++ b/drivers/media/rc/img-ir/img-ir-rc6.c @@ -0,0 +1,117 @@ +/* + * ImgTec IR Decoder setup for Philips RC-6 protocol. + * + * Copyright 2012-2014 Imagination Technologies Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#include "img-ir-hw.h" + +/* Convert RC6 data to a scancode */ +static int img_ir_rc6_scancode(int len, u64 raw, u64 enabled_protocols, + struct img_ir_scancode_req *request) +{ + unsigned int addr, cmd, mode, trl1, trl2; + + /* + * Due to a side effect of the decoder handling the double length + * Trailer bit, the header information is a bit scrambled, and the + * raw data is shifted incorrectly. + * This workaround effectively recovers the header bits. + * + * The Header field should look like this: + * + * StartBit ModeBit2 ModeBit1 ModeBit0 TrailerBit + * + * But what we get is: + * + * ModeBit2 ModeBit1 ModeBit0 TrailerBit1 TrailerBit2 + * + * The start bit is not important to recover the scancode. + */ + + raw >>= 27; + + trl1 = (raw >> 17) & 0x01; + trl2 = (raw >> 16) & 0x01; + + mode = (raw >> 18) & 0x07; + addr = (raw >> 8) & 0xff; + cmd = raw & 0xff; + + /* + * Due to the above explained irregularity the trailer bits cannot + * have the same value. + */ + if (trl1 == trl2) + return -EINVAL; + + /* Only mode 0 supported for now */ + if (mode) + return -EINVAL; + + request->protocol = RC_TYPE_RC6_0; + request->scancode = addr << 8 | cmd; + request->toggle = trl2; + return IMG_IR_SCANCODE; +} + +/* Convert RC6 scancode to RC6 data filter */ +static int img_ir_rc6_filter(const struct rc_scancode_filter *in, + struct img_ir_filter *out, u64 protocols) +{ + /* Not supported by the hw. */ + return -EINVAL; +} + +/* + * RC-6 decoder + * see http://www.sbprojects.com/knowledge/ir/rc6.php + */ +struct img_ir_decoder img_ir_rc6 = { + .type = RC_BIT_RC6_0, + .control = { + .bitorien = 1, + .code_type = IMG_IR_CODETYPE_BIPHASE, + .decoden = 1, + .decodinpol = 1, + }, + /* main timings */ + .tolerance = 20, + /* + * Due to a quirk in the img-ir decoder, default header values do + * not work, the values described below were extracted from + * successful RTL test cases. + */ + .timings = { + /* leader symbol */ + .ldr = { + .pulse = { 650 }, + .space = { 660 }, + }, + /* 0 symbol */ + .s00 = { + .pulse = { 370 }, + .space = { 370 }, + }, + /* 01 symbol */ + .s01 = { + .pulse = { 370 }, + .space = { 370 }, + }, + /* free time */ + .ft = { + .minlen = 21, + .maxlen = 21, + .ft_min = 2666, /* 2.666 ms */ + }, + }, + + /* scancode logic */ + .scancode = img_ir_rc6_scancode, + .filter = img_ir_rc6_filter, +}; |