linux-stable/drivers/media/rc/ir-xmp-decoder.c
Heiner Kallweit d80ca8bd71 [media] media: rc: move check whether a protocol is enabled to the core
Checking whether a protocol is enabled and calling the related decoder
functions should be done by the rc core, not the protocol handlers.

Properly handle lirc considering that no protocol bit is set for lirc.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2015-11-19 11:39:17 -02:00

222 lines
5.9 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 (!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");