/* ir-rc5-decoder.c - handle RC5(x) IR Pulse/Space protocol
|
*
|
* Copyright (C) 2010 by Mauro Carvalho Chehab <mchehab@redhat.com>
|
*
|
* GNU General Public License for more details.
|
*/
|
|
/*
|
* This code handles 14 bits RC5 protocols and 20 bits RC5x protocols.
|
* There are other variants that use a different number of bits.
|
* This is currently unsupported.
|
* It considers a carrier of 36 kHz, with a total of 14/20 bits, where
|
* the first two bits are start bits, and a third one is a filing bit
|
*/
|
|
#include <common.h>
|
#include "bitrev.h"
|
#include "sunxi-ir.h"
|
|
#define NEC_NBITS (32)
|
#define NEC_UNIT (562500) /* ns */
|
#define NEC_HEADER_PULSE (16 * NEC_UNIT)
|
#define NECX_HEADER_PULSE (8 * NEC_UNIT) /* Less common NEC variant */
|
#define NEC_HEADER_SPACE (8 * NEC_UNIT)
|
#define NEC_REPEAT_SPACE (4 * NEC_UNIT)
|
#define NEC_BIT_PULSE (1 * NEC_UNIT)
|
#define NEC_BIT_0_SPACE (1 * NEC_UNIT)
|
#define NEC_BIT_1_SPACE (3 * NEC_UNIT)
|
#define NEC_TRAILER_PULSE (1 * NEC_UNIT)
|
#define NEC_TRAILER_SPACE (10 * NEC_UNIT) /* even longer in reality */
|
#define NECX_REPEAT_BITS 1
|
|
enum nec_state {
|
STATE_INACTIVE,
|
STATE_HEADER_SPACE,
|
STATE_BIT_PULSE,
|
STATE_BIT_SPACE,
|
STATE_TRAILER_PULSE,
|
STATE_TRAILER_SPACE,
|
};
|
|
int ir_nec_decode(struct ir_raw_buffer *ir_raw, struct ir_raw_event ev)
|
{
|
struct nec_dec *data = &(ir_raw->nec);
|
u32 scancode;
|
u8 address, not_address, command, not_command;
|
bool send_32bits = false;
|
/*
|
if (!(dev->enabled_protocols & RC_BIT_NEC))
|
return 0;
|
*/
|
if (!is_timing_event(ev)) {
|
if (ev.reset)
|
data->state = STATE_INACTIVE;
|
return 0;
|
}
|
|
debug("line:%d NEC decode started at state %d (%uus %s)\n", __LINE__,
|
data->state, TO_US(ev.duration), TO_STR(ev.pulse));
|
|
switch (data->state) {
|
case STATE_INACTIVE:
|
if (!ev.pulse)
|
break;
|
|
if (eq_margin(ev.duration, NEC_HEADER_PULSE, NEC_UNIT * 2)) {
|
data->is_nec_x = false;
|
data->necx_repeat = false;
|
} else if (eq_margin(ev.duration, NECX_HEADER_PULSE,
|
NEC_UNIT / 2))
|
data->is_nec_x = true;
|
else
|
break;
|
|
data->count = 0;
|
data->state = STATE_HEADER_SPACE;
|
return 0;
|
|
case STATE_HEADER_SPACE:
|
if (ev.pulse)
|
break;
|
|
if (eq_margin(ev.duration, NEC_HEADER_SPACE, NEC_UNIT)) {
|
data->state = STATE_BIT_PULSE;
|
return 0;
|
} else if (eq_margin(ev.duration, NEC_REPEAT_SPACE,
|
NEC_UNIT / 2)) {
|
/* //if (!dev->keypressed) { */
|
/* // pr_notice("Discarding last key repeat: event after key up\n"); */
|
/* //} else { */
|
/* // rc_repeat(dev); */
|
pr_notice("line:%d Repeat last key\n", __LINE__);
|
data->state = STATE_TRAILER_PULSE;
|
data->curt_repeat = true;
|
/* //} */
|
return 0;
|
}
|
|
break;
|
|
case STATE_BIT_PULSE:
|
if (!ev.pulse)
|
break;
|
|
if (!eq_margin(ev.duration, NEC_BIT_PULSE, NEC_UNIT / 2))
|
break;
|
|
data->state = STATE_BIT_SPACE;
|
data->curt_repeat = false;
|
return 0;
|
|
case STATE_BIT_SPACE:
|
if (ev.pulse)
|
break;
|
|
if (data->necx_repeat && data->count == NECX_REPEAT_BITS &&
|
geq_margin(ev.duration, NEC_TRAILER_SPACE, NEC_UNIT / 2)) {
|
pr_notice("line:%d Repeat last key\n", __LINE__);
|
/* //rc_repeat(dev); */
|
data->state = STATE_INACTIVE;
|
return 0;
|
|
} else if (data->count > NECX_REPEAT_BITS)
|
data->necx_repeat = false;
|
|
data->bits <<= 1;
|
if (eq_margin(ev.duration, NEC_BIT_1_SPACE, NEC_UNIT / 2))
|
data->bits |= 1;
|
else if (!eq_margin(ev.duration, NEC_BIT_0_SPACE, NEC_UNIT / 2))
|
break;
|
data->count++;
|
|
if (data->count == NEC_NBITS)
|
data->state = STATE_TRAILER_PULSE;
|
else
|
data->state = STATE_BIT_PULSE;
|
|
return 0;
|
|
case STATE_TRAILER_PULSE:
|
if (!ev.pulse)
|
break;
|
|
if (!eq_margin(ev.duration, NEC_TRAILER_PULSE, NEC_UNIT / 2))
|
break;
|
|
data->state = STATE_TRAILER_SPACE;
|
return 0;
|
|
case STATE_TRAILER_SPACE:
|
if (ev.pulse)
|
break;
|
|
if (!geq_margin(ev.duration, NEC_TRAILER_SPACE, NEC_UNIT / 2))
|
break;
|
|
address = bitrev8((data->bits >> 24) & 0xff);
|
not_address = bitrev8((data->bits >> 16) & 0xff);
|
command = bitrev8((data->bits >> 8) & 0xff);
|
not_command = bitrev8((data->bits >> 0) & 0xff);
|
|
if ((command ^ not_command) != 0xff) {
|
pr_notice("NEC checksum error: received 0x%08x\n",
|
data->bits);
|
send_32bits = true;
|
}
|
|
if (send_32bits) {
|
/* NEC transport, but modified protocol, used by at
|
* least Apple and TiVo remotes */
|
scancode = data->bits;
|
pr_notice("NEC (modified) scancode 0x%08x\n", scancode);
|
} else {
|
/* Extended NEC */
|
scancode = address << 8 | not_address << 16 | command;
|
pr_notice("NEC scancode 0x%06x\n", scancode);
|
}
|
|
if (data->is_nec_x)
|
data->necx_repeat = true;
|
|
pr_notice("scancode key down 0x%06x\n", scancode);
|
rc_keydown(ir_raw, scancode, 0);
|
data->state = STATE_INACTIVE;
|
return 0;
|
}
|
|
debug("NEC decode failed at count %d state %d (%uus %s)\n", data->count,
|
data->state, TO_US(ev.duration), TO_STR(ev.pulse));
|
data->state = STATE_INACTIVE;
|
return -1;
|
}
|
