korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-11 21:38:32 +08:00
Code Issues Packages Projects Releases Wiki Activity

[media] ir-rc6-decoder: Support RC6-6A variable length data

Browse Source 
This patch to the IR RC6 decoder adds support for variable length
mode-6A frames which can range in size from 8 to 128 bits.  Please refer
to the following link for a detailed explanation or RC6 frames:
http://slydiman.narod.ru/scr/kb/rc6.htm

This change removes the assumption that frames are fixed length
(currently either 24 or 32 data bits) and actually counts the number of
bits until an end of frame marker is seen.

[mchehab@redhat.com: Tested with a RC-6(0) IR - 16 bits]
Tested-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
lawrence rust 2011-10-31 08:39:32 -03:00 committed by Mauro Carvalho Chehab
parent 12cbfd0a3c
commit db9bc660cf
1 changed files with 42 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

69
drivers/media/rc/ir-rc6-decoder.c
View File

@ -18,24 +18,31 @@
/*
* This decoder currently supports:
* RC6-0-16 (standard toggle bit in header)
* RC6-6A-20 (no toggle bit)
* RC6-6A-24 (no toggle bit)
* RC6-6A-32 (MCE version with toggle bit in body)
*/
#define RC6_UNIT 444444 /* us */
#define RC6_UNIT 444444 /* nanosecs */
#define RC6_HEADER_NBITS 4 /* not including toggle bit */
#define RC6_0_NBITS 16
#define RC6_6A_SMALL_NBITS 24
#define RC6_6A_LARGE_NBITS 32
#define RC6_6A_32_NBITS 32
#define RC6_6A_NBITS 128 /* Variable 8..128 */
#define RC6_PREFIX_PULSE (6 * RC6_UNIT)
#define RC6_PREFIX_SPACE (2 * RC6_UNIT)
#define RC6_BIT_START (1 * RC6_UNIT)
#define RC6_BIT_END (1 * RC6_UNIT)
#define RC6_TOGGLE_START (2 * RC6_UNIT)
#define RC6_TOGGLE_END (2 * RC6_UNIT)
#define RC6_SUFFIX_SPACE (6 * RC6_UNIT)
#define RC6_MODE_MASK 0x07 /* for the header bits */
#define RC6_STARTBIT_MASK 0x08 /* for the header bits */
#define RC6_6A_MCE_TOGGLE_MASK 0x8000 /* for the body bits */
#define RC6_6A_LCC_MASK 0xffff0000 /* RC6-6A-32 long customer code mask */
#define RC6_6A_MCE_CC 0x800f0000 /* MCE customer code */
#ifndef CHAR_BIT
#define CHAR_BIT 8 /* Normally in <limits.h> */
#endif
enum rc6_mode {
RC6_MODE_0,
@ -125,6 +132,7 @@ again:
break;
data->state = STATE_HEADER_BIT_START;
data->header = 0;
return 0;
case STATE_HEADER_BIT_START:
@ -171,20 +179,14 @@ again:
data->state = STATE_BODY_BIT_START;
decrease_duration(&ev, RC6_TOGGLE_END);
data->count = 0;
data->body = 0;
switch (rc6_mode(data)) {
case RC6_MODE_0:
data->wanted_bits = RC6_0_NBITS;
break;
case RC6_MODE_6A:
/* This might look weird, but we basically
check the value of the first body bit to
determine the number of bits in mode 6A */
if ((!ev.pulse && !geq_margin(ev.duration, RC6_UNIT, RC6_UNIT / 2)) ||
geq_margin(ev.duration, RC6_UNIT, RC6_UNIT / 2))
data->wanted_bits = RC6_6A_LARGE_NBITS;
else
data->wanted_bits = RC6_6A_SMALL_NBITS;
data->wanted_bits = RC6_6A_NBITS;
break;
default:
IR_dprintk(1, "RC6 unknown mode\n");
@ -193,15 +195,21 @@ again:
goto again;
case STATE_BODY_BIT_START:
if (!eq_margin(ev.duration, RC6_BIT_START, RC6_UNIT / 2))
break;
data->body <<= 1;
if (ev.pulse)
data->body |= 1;
data->count++;
data->state = STATE_BODY_BIT_END;
return 0;
if (eq_margin(ev.duration, RC6_BIT_START, RC6_UNIT / 2)) {
/* Discard LSB's that won't fit in data->body */
if (data->count++ < CHAR_BIT * sizeof data->body) {
data->body <<= 1;
if (ev.pulse)
data->body |= 1;
}
data->state = STATE_BODY_BIT_END;
return 0;
} else if (RC6_MODE_6A == rc6_mode(data) && !ev.pulse &&
geq_margin(ev.duration, RC6_SUFFIX_SPACE, RC6_UNIT / 2)) {
data->state = STATE_FINISHED;
goto again;
}
break;
case STATE_BODY_BIT_END:
if (!is_transition(&ev, &dev->raw->prev_ev))
@ -221,20 +229,27 @@ again:
switch (rc6_mode(data)) {
case RC6_MODE_0:
scancode = data->body & 0xffff;
scancode = data->body;
toggle = data->toggle;
IR_dprintk(1, "RC6(0) scancode 0x%04x (toggle: %u)\n",
scancode, toggle);
break;
case RC6_MODE_6A:
if (data->wanted_bits == RC6_6A_LARGE_NBITS) {
toggle = data->body & RC6_6A_MCE_TOGGLE_MASK ? 1 : 0;
scancode = data->body & ~RC6_6A_MCE_TOGGLE_MASK;
} else {
toggle = 0;
scancode = data->body & 0xffffff;
if (data->count > CHAR_BIT * sizeof data->body) {
IR_dprintk(1, "RC6 too many (%u) data bits\n",
data->count);
goto out;
}
scancode = data->body;
if (data->count == RC6_6A_32_NBITS &&
(scancode & RC6_6A_LCC_MASK) == RC6_6A_MCE_CC) {
/* MCE RC */
toggle = (scancode & RC6_6A_MCE_TOGGLE_MASK) ? 1 : 0;
scancode &= ~RC6_6A_MCE_TOGGLE_MASK;
} else {
toggle = 0;
}
IR_dprintk(1, "RC6(6A) scancode 0x%08x (toggle: %u)\n",
scancode, toggle);
break;