mirror of https://gitee.com/openkylin/linux.git
155 lines
3.8 KiB
C
155 lines
3.8 KiB
C
/* ir-rc5-sz-decoder.c - handle RC5 Streamzap IR Pulse/Space protocol
|
|
*
|
|
* Copyright (C) 2010 by Mauro Carvalho Chehab <mchehab@redhat.com>
|
|
* Copyright (C) 2010 by Jarod Wilson <jarod@redhat.com>
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
/*
|
|
* This code handles the 15 bit RC5-ish protocol used by the Streamzap
|
|
* PC Remote.
|
|
* It considers a carrier of 36 kHz, with a total of 15 bits, where
|
|
* the first two bits are start bits, and a third one is a filing bit
|
|
*/
|
|
|
|
#include "rc-core-priv.h"
|
|
#include <linux/module.h>
|
|
|
|
#define RC5_SZ_NBITS 15
|
|
#define RC5_UNIT 888888 /* ns */
|
|
#define RC5_BIT_START (1 * RC5_UNIT)
|
|
#define RC5_BIT_END (1 * RC5_UNIT)
|
|
|
|
enum rc5_sz_state {
|
|
STATE_INACTIVE,
|
|
STATE_BIT_START,
|
|
STATE_BIT_END,
|
|
STATE_FINISHED,
|
|
};
|
|
|
|
/**
|
|
* ir_rc5_sz_decode() - Decode one RC-5 Streamzap pulse or space
|
|
* @dev: the struct rc_dev descriptor of the device
|
|
* @ev: the struct ir_raw_event descriptor of the pulse/space
|
|
*
|
|
* This function returns -EINVAL if the pulse violates the state machine
|
|
*/
|
|
static int ir_rc5_sz_decode(struct rc_dev *dev, struct ir_raw_event ev)
|
|
{
|
|
struct rc5_sz_dec *data = &dev->raw->rc5_sz;
|
|
u8 toggle, command, system;
|
|
u32 scancode;
|
|
|
|
if (!(dev->enabled_protocols & RC_BIT_RC5_SZ))
|
|
return 0;
|
|
|
|
if (!is_timing_event(ev)) {
|
|
if (ev.reset)
|
|
data->state = STATE_INACTIVE;
|
|
return 0;
|
|
}
|
|
|
|
if (!geq_margin(ev.duration, RC5_UNIT, RC5_UNIT / 2))
|
|
goto out;
|
|
|
|
again:
|
|
IR_dprintk(2, "RC5-sz decode started at state %i (%uus %s)\n",
|
|
data->state, TO_US(ev.duration), TO_STR(ev.pulse));
|
|
|
|
if (!geq_margin(ev.duration, RC5_UNIT, RC5_UNIT / 2))
|
|
return 0;
|
|
|
|
switch (data->state) {
|
|
|
|
case STATE_INACTIVE:
|
|
if (!ev.pulse)
|
|
break;
|
|
|
|
data->state = STATE_BIT_START;
|
|
data->count = 1;
|
|
data->wanted_bits = RC5_SZ_NBITS;
|
|
decrease_duration(&ev, RC5_BIT_START);
|
|
goto again;
|
|
|
|
case STATE_BIT_START:
|
|
if (!eq_margin(ev.duration, RC5_BIT_START, RC5_UNIT / 2))
|
|
break;
|
|
|
|
data->bits <<= 1;
|
|
if (!ev.pulse)
|
|
data->bits |= 1;
|
|
data->count++;
|
|
data->state = STATE_BIT_END;
|
|
return 0;
|
|
|
|
case STATE_BIT_END:
|
|
if (!is_transition(&ev, &dev->raw->prev_ev))
|
|
break;
|
|
|
|
if (data->count == data->wanted_bits)
|
|
data->state = STATE_FINISHED;
|
|
else
|
|
data->state = STATE_BIT_START;
|
|
|
|
decrease_duration(&ev, RC5_BIT_END);
|
|
goto again;
|
|
|
|
case STATE_FINISHED:
|
|
if (ev.pulse)
|
|
break;
|
|
|
|
/* RC5-sz */
|
|
command = (data->bits & 0x0003F) >> 0;
|
|
system = (data->bits & 0x02FC0) >> 6;
|
|
toggle = (data->bits & 0x01000) ? 1 : 0;
|
|
scancode = system << 6 | command;
|
|
|
|
IR_dprintk(1, "RC5-sz scancode 0x%04x (toggle: %u)\n",
|
|
scancode, toggle);
|
|
|
|
rc_keydown(dev, scancode, toggle);
|
|
data->state = STATE_INACTIVE;
|
|
return 0;
|
|
}
|
|
|
|
out:
|
|
IR_dprintk(1, "RC5-sz decode failed at state %i (%uus %s)\n",
|
|
data->state, TO_US(ev.duration), TO_STR(ev.pulse));
|
|
data->state = STATE_INACTIVE;
|
|
return -EINVAL;
|
|
}
|
|
|
|
static struct ir_raw_handler rc5_sz_handler = {
|
|
.protocols = RC_BIT_RC5_SZ,
|
|
.decode = ir_rc5_sz_decode,
|
|
};
|
|
|
|
static int __init ir_rc5_sz_decode_init(void)
|
|
{
|
|
ir_raw_handler_register(&rc5_sz_handler);
|
|
|
|
printk(KERN_INFO "IR RC5 (streamzap) protocol handler initialized\n");
|
|
return 0;
|
|
}
|
|
|
|
static void __exit ir_rc5_sz_decode_exit(void)
|
|
{
|
|
ir_raw_handler_unregister(&rc5_sz_handler);
|
|
}
|
|
|
|
module_init(ir_rc5_sz_decode_init);
|
|
module_exit(ir_rc5_sz_decode_exit);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>");
|
|
MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
|
|
MODULE_DESCRIPTION("RC5 (streamzap) IR protocol decoder");
|