226 lines
6 KiB
C
226 lines
6 KiB
C
![]() |
/* ir-xmp-decoder.c - handle XMP IR Pulse/Space protocol
|
||
|
*
|
||
|
* Copyright (C) 2014 by Marcel Mol
|
||
|
*
|
||
|
* 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 version 2 of the License.
|
||
|
*
|
||
|
* This program is distributed in the hope that it will be useful,
|
||
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
* GNU General Public License for more details.
|
||
|
*
|
||
|
* - Based on info from http://www.hifi-remote.com
|
||
|
* - Ignore Toggle=9 frames
|
||
|
* - Ignore XMP-1 XMP-2 difference, always store 16 bit OBC
|
||
|
*/
|
||
|
|
||
|
#include <linux/bitrev.h>
|
||
|
#include <linux/module.h>
|
||
|
#include "rc-core-priv.h"
|
||
|
|
||
|
#define XMP_UNIT 136000 /* ns */
|
||
|
#define XMP_LEADER 210000 /* ns */
|
||
|
#define XMP_NIBBLE_PREFIX 760000 /* ns */
|
||
|
#define XMP_HALFFRAME_SPACE 13800000 /* ns */
|
||
|
#define XMP_TRAILER_SPACE 20000000 /* should be 80ms but not all dureation supliers can go that high */
|
||
|
|
||
|
enum xmp_state {
|
||
|
STATE_INACTIVE,
|
||
|
STATE_LEADER_PULSE,
|
||
|
STATE_NIBBLE_SPACE,
|
||
|
};
|
||
|
|
||
|
/**
|
||
|
* ir_xmp_decode() - Decode one XMP pulse or space
|
||
|
* @dev: the struct rc_dev descriptor of the device
|
||
|
* @duration: the struct ir_raw_event descriptor of the pulse/space
|
||
|
*
|
||
|
* This function returns -EINVAL if the pulse violates the state machine
|
||
|
*/
|
||
|
static int ir_xmp_decode(struct rc_dev *dev, struct ir_raw_event ev)
|
||
|
{
|
||
|
struct xmp_dec *data = &dev->raw->xmp;
|
||
|
|
||
|
if (!(dev->enabled_protocols & RC_BIT_XMP))
|
||
|
return 0;
|
||
|
|
||
|
if (!is_timing_event(ev)) {
|
||
|
if (ev.reset)
|
||
|
data->state = STATE_INACTIVE;
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
IR_dprintk(2, "XMP decode started at state %d %d (%uus %s)\n",
|
||
|
data->state, data->count, TO_US(ev.duration), TO_STR(ev.pulse));
|
||
|
|
||
|
switch (data->state) {
|
||
|
|
||
|
case STATE_INACTIVE:
|
||
|
if (!ev.pulse)
|
||
|
break;
|
||
|
|
||
|
if (eq_margin(ev.duration, XMP_LEADER, XMP_UNIT / 2)) {
|
||
|
data->count = 0;
|
||
|
data->state = STATE_NIBBLE_SPACE;
|
||
|
}
|
||
|
|
||
|
return 0;
|
||
|
|
||
|
case STATE_LEADER_PULSE:
|
||
|
if (!ev.pulse)
|
||
|
break;
|
||
|
|
||
|
if (eq_margin(ev.duration, XMP_LEADER, XMP_UNIT / 2))
|
||
|
data->state = STATE_NIBBLE_SPACE;
|
||
|
|
||
|
return 0;
|
||
|
|
||
|
case STATE_NIBBLE_SPACE:
|
||
|
if (ev.pulse)
|
||
|
break;
|
||
|
|
||
|
if (geq_margin(ev.duration, XMP_TRAILER_SPACE, XMP_NIBBLE_PREFIX)) {
|
||
|
int divider, i;
|
||
|
u8 addr, subaddr, subaddr2, toggle, oem, obc1, obc2, sum1, sum2;
|
||
|
u32 *n;
|
||
|
u32 scancode;
|
||
|
|
||
|
if (data->count != 16) {
|
||
|
IR_dprintk(2, "received TRAILER period at index %d: %u\n",
|
||
|
data->count, ev.duration);
|
||
|
data->state = STATE_INACTIVE;
|
||
|
return -EINVAL;
|
||
|
}
|
||
|
|
||
|
n = data->durations;
|
||
|
/*
|
||
|
* the 4th nibble should be 15 so base the divider on this
|
||
|
* to transform durations into nibbles. Substract 2000 from
|
||
|
* the divider to compensate for fluctuations in the signal
|
||
|
*/
|
||
|
divider = (n[3] - XMP_NIBBLE_PREFIX) / 15 - 2000;
|
||
|
if (divider < 50) {
|
||
|
IR_dprintk(2, "divider to small %d.\n", divider);
|
||
|
data->state = STATE_INACTIVE;
|
||
|
return -EINVAL;
|
||
|
}
|
||
|
|
||
|
/* convert to nibbles and do some sanity checks */
|
||
|
for (i = 0; i < 16; i++)
|
||
|
n[i] = (n[i] - XMP_NIBBLE_PREFIX) / divider;
|
||
|
sum1 = (15 + n[0] + n[1] + n[2] + n[3] +
|
||
|
n[4] + n[5] + n[6] + n[7]) % 16;
|
||
|
sum2 = (15 + n[8] + n[9] + n[10] + n[11] +
|
||
|
n[12] + n[13] + n[14] + n[15]) % 16;
|
||
|
|
||
|
if (sum1 != 15 || sum2 != 15) {
|
||
|
IR_dprintk(2, "checksum errors sum1=0x%X sum2=0x%X\n",
|
||
|
sum1, sum2);
|
||
|
data->state = STATE_INACTIVE;
|
||
|
return -EINVAL;
|
||
|
}
|
||
|
|
||
|
subaddr = n[0] << 4 | n[2];
|
||
|
subaddr2 = n[8] << 4 | n[11];
|
||
|
oem = n[4] << 4 | n[5];
|
||
|
addr = n[6] << 4 | n[7];
|
||
|
toggle = n[10];
|
||
|
obc1 = n[12] << 4 | n[13];
|
||
|
obc2 = n[14] << 4 | n[15];
|
||
|
if (subaddr != subaddr2) {
|
||
|
IR_dprintk(2, "subaddress nibbles mismatch 0x%02X != 0x%02X\n",
|
||
|
subaddr, subaddr2);
|
||
|
data->state = STATE_INACTIVE;
|
||
|
return -EINVAL;
|
||
|
}
|
||
|
if (oem != 0x44)
|
||
|
IR_dprintk(1, "Warning: OEM nibbles 0x%02X. Expected 0x44\n",
|
||
|
oem);
|
||
|
|
||
|
scancode = addr << 24 | subaddr << 16 |
|
||
|
obc1 << 8 | obc2;
|
||
|
IR_dprintk(1, "XMP scancode 0x%06x\n", scancode);
|
||
|
|
||
|
if (toggle == 0) {
|
||
|
rc_keydown(dev, RC_TYPE_XMP, scancode, 0);
|
||
|
} else {
|
||
|
rc_repeat(dev);
|
||
|
IR_dprintk(1, "Repeat last key\n");
|
||
|
}
|
||
|
data->state = STATE_INACTIVE;
|
||
|
|
||
|
return 0;
|
||
|
|
||
|
} else if (geq_margin(ev.duration, XMP_HALFFRAME_SPACE, XMP_NIBBLE_PREFIX)) {
|
||
|
/* Expect 8 or 16 nibble pulses. 16 in case of 'final' frame */
|
||
|
if (data->count == 16) {
|
||
|
IR_dprintk(2, "received half frame pulse at index %d. Probably a final frame key-up event: %u\n",
|
||
|
data->count, ev.duration);
|
||
|
/*
|
||
|
* TODO: for now go back to half frame position
|
||
|
* so trailer can be found and key press
|
||
|
* can be handled.
|
||
|
*/
|
||
|
data->count = 8;
|
||
|
}
|
||
|
|
||
|
else if (data->count != 8)
|
||
|
IR_dprintk(2, "received half frame pulse at index %d: %u\n",
|
||
|
data->count, ev.duration);
|
||
|
data->state = STATE_LEADER_PULSE;
|
||
|
|
||
|
return 0;
|
||
|
|
||
|
} else if (geq_margin(ev.duration, XMP_NIBBLE_PREFIX, XMP_UNIT)) {
|
||
|
/* store nibble raw data, decode after trailer */
|
||
|
if (data->count == 16) {
|
||
|
IR_dprintk(2, "to many pulses (%d) ignoring: %u\n",
|
||
|
data->count, ev.duration);
|
||
|
data->state = STATE_INACTIVE;
|
||
|
return -EINVAL;
|
||
|
}
|
||
|
data->durations[data->count] = ev.duration;
|
||
|
data->count++;
|
||
|
data->state = STATE_LEADER_PULSE;
|
||
|
|
||
|
return 0;
|
||
|
|
||
|
}
|
||
|
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
IR_dprintk(1, "XMP 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 -EINVAL;
|
||
|
}
|
||
|
|
||
|
static struct ir_raw_handler xmp_handler = {
|
||
|
.protocols = RC_BIT_XMP,
|
||
|
.decode = ir_xmp_decode,
|
||
|
};
|
||
|
|
||
|
static int __init ir_xmp_decode_init(void)
|
||
|
{
|
||
|
ir_raw_handler_register(&xmp_handler);
|
||
|
|
||
|
printk(KERN_INFO "IR XMP protocol handler initialized\n");
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static void __exit ir_xmp_decode_exit(void)
|
||
|
{
|
||
|
ir_raw_handler_unregister(&xmp_handler);
|
||
|
}
|
||
|
|
||
|
module_init(ir_xmp_decode_init);
|
||
|
module_exit(ir_xmp_decode_exit);
|
||
|
|
||
|
MODULE_LICENSE("GPL");
|
||
|
MODULE_AUTHOR("Marcel Mol <marcel@mesa.nl>");
|
||
|
MODULE_AUTHOR("MESA Consulting (http://www.mesa.nl)");
|
||
|
MODULE_DESCRIPTION("XMP IR protocol decoder");
|