/* ir-sanyo-decoder.c - handle SANYO IR Pulse/Space protocol
*
* Copyright (C) 2011 by Mauro Carvalho Chehab <mchehab@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 protocol uses the NEC protocol timings. However, data is formatted as:
* 13 bits Custom Code
* 13 bits NOT(Custom Code)
* 8 bits Key data
* 8 bits NOT(Key data)
*
* According with LIRC, this protocol is used on Sanyo, Aiwa and Chinon
* Information for this protocol is available at the Sanyo LC7461 datasheet.
*/
#include <linux/module.h>
#include <linux/bitrev.h>
#include "rc-core-priv.h"
#define SANYO_NBITS (13+13+8+8)
#define SANYO_UNIT 562500 /* ns */
#define SANYO_HEADER_PULSE (16 * SANYO_UNIT)
#define SANYO_HEADER_SPACE (8 * SANYO_UNIT)
#define SANYO_BIT_PULSE (1 * SANYO_UNIT)
#define SANYO_BIT_0_SPACE (1 * SANYO_UNIT)
#define SANYO_BIT_1_SPACE (3 * SANYO_UNIT)
#define SANYO_REPEAT_SPACE (150 * SANYO_UNIT)
#define SANYO_TRAILER_PULSE (1 * SANYO_UNIT)
#define SANYO_TRAILER_SPACE (10 * SANYO_UNIT) /* in fact, 42 */
enum sanyo_state {
STATE_INACTIVE,
STATE_HEADER_SPACE,
STATE_BIT_PULSE,
STATE_BIT_SPACE,
STATE_TRAILER_PULSE,
STATE_TRAILER_SPACE,
};
/**
* ir_sanyo_decode() - Decode one SANYO 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_sanyo_decode(struct rc_dev *dev, struct ir_raw_event ev)
{
struct sanyo_dec *data = &dev->raw->sanyo;
u32 scancode;
u8 address, not_address, command, not_command;
if (!(dev->raw->enabled_protocols & RC_TYPE_SANYO))
return 0;
if (!is_timing_event(ev)) {
if (ev.reset) {
IR_dprintk(1, "SANYO event reset received. reset to state 0\n");
data->state = STATE_INACTIVE;
}
return 0;
}
IR_dprintk(2, "SANYO decode started at state %d (%uus %s)\n",
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, SANYO_HEADER_PULSE, SANYO_UNIT / 2)) {
data->count = 0;
data->state = STATE_HEADER_SPACE;
return 0;
}
break;
case STATE_HEADER_SPACE:
if (ev.pulse)
break;
if (eq_margin(ev.duration, SANYO_HEADER_SPACE, SANYO_UNIT / 2)) {
data->state = STATE_BIT_PULSE;
return 0;
}
break;
case STATE_BIT_PULSE:
if (!ev.pulse)
break;
if (!eq_margin(ev.duration, SANYO_BIT_PULSE, SANYO_UNIT / 2))
break;
data->state = STATE_BIT_SPACE;
return 0;
case STATE_BIT_SPACE:
if (ev.pulse)
break;
if (!data->count && geq_margin(ev.duration, SANYO_REPEAT_SPACE, SANYO_UNIT / 2)) {
if (!dev->keypressed) {
IR_dprintk(1, "SANYO discarding last key repeat: event after key up\n");
} else {
rc_repeat(dev);
IR_dprintk(1, "SANYO repeat last key\n");
data->state = STATE_INACTIVE;
}
return 0;
}
data->bits <<= 1;
if (eq_margin(ev.duration, SANYO_BIT_1_SPACE, SANYO_UNIT / 2))
data->bits |= 1;
else if (!eq_margin(ev.duration, SANYO_BIT_0_SPACE, SANYO_UNIT / 2))
break;
data->count++;
if (data->count == SANYO_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, SANYO_TRAILER_PULSE, SANYO_UNIT / 2))
break;
data->state = STATE_TRAILER_SPACE;
return 0;
case STATE_TRAILER_SPACE:
if (ev.pulse)
break;
if (!geq_margin(ev.duration, SANYO_TRAILER_SPACE, SANYO_UNIT / 2))
break;
address = bitrev16((data->bits >> 29) & 0x1fff) >> 3;
not_address = bitrev16((data->bits >> 16) & 0x1fff) >> 3;
command = bitrev8((data->bits >> 8) & 0xff);
not_command = bitrev8((data->bits >> 0) & 0xff);
if ((command ^ not_command) != 0xff) {
IR_dprintk(1, "SANYO checksum error: received 0x%08Lx\n",
data->bits);
data->state = STATE_INACTIVE;
return 0;
}
scancode = address << 8 | command;
IR_dprintk(1, "SANYO scancode: 0x%06x\n", scancode);
rc_keydown(dev, scancode, 0);
data->state = STATE_INACTIVE;
return 0;
}
IR_dprintk(1, "SANYO 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 sanyo_handler = {
.protocols = RC_TYPE_SANYO,
.decode = ir_sanyo_decode,
};
static int __init ir_sanyo_decode_init(void)
{
ir_raw_handler_register(&sanyo_handler);
printk(KERN_INFO "IR SANYO protocol handler initialized\n");
return 0;
}
static void __exit ir_sanyo_decode_exit(void)
{
ir_raw_handler_unregister(&sanyo_handler);
}
module_init(ir_sanyo_decode_init);
module_exit(ir_sanyo_decode_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>");
MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
MODULE_DESCRIPTION("SANYO IR protocol decoder");
