linux-imx

/* ir-jvc-decoder.c - handle JVC IR Pulse/Space protocol

 *

 * Copyright (C) 2010 by David Härdeman <david@hardeman.nu>

 *

 * 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.

 */

​

#include <linux/bitrev.h>

#include <linux/module.h>

#include "rc-core-priv.h"

​

#define JVC_NBITS       16      /* dev(8) + func(8) */

#define JVC_UNIT        525000      /* ns */

#define JVC_HEADER_PULSE    (16 * JVC_UNIT) /* lack of header -> repeat */

#define JVC_HEADER_SPACE    (8  * JVC_UNIT)

#define JVC_BIT_PULSE       (1  * JVC_UNIT)

#define JVC_BIT_0_SPACE     (1  * JVC_UNIT)

#define JVC_BIT_1_SPACE     (3  * JVC_UNIT)

#define JVC_TRAILER_PULSE   (1  * JVC_UNIT)

#define JVC_TRAILER_SPACE   (35 * JVC_UNIT)

​

enum jvc_state {

    STATE_INACTIVE,

    STATE_HEADER_SPACE,

    STATE_BIT_PULSE,

    STATE_BIT_SPACE,

    STATE_TRAILER_PULSE,

    STATE_TRAILER_SPACE,

    STATE_CHECK_REPEAT,

};

​

/**

 * ir_jvc_decode() - Decode one JVC 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_jvc_decode(struct rc_dev *dev, struct ir_raw_event ev)

{

    struct jvc_dec *data = &dev->raw->jvc;

​

    if (!is_timing_event(ev)) {

        if (ev.reset)

            data->state = STATE_INACTIVE;

        return 0;

    }

​

    if (!geq_margin(ev.duration, JVC_UNIT, JVC_UNIT / 2))

        goto out;

​

    dev_dbg(&dev->dev, "JVC decode started at state %d (%uus %s)\n",

        data->state, TO_US(ev.duration), TO_STR(ev.pulse));

​

again:

    switch (data->state) {

​

    case STATE_INACTIVE:

        if (!ev.pulse)

            break;

​

        if (!eq_margin(ev.duration, JVC_HEADER_PULSE, JVC_UNIT / 2))

            break;

​

        data->count = 0;

        data->first = true;

        data->toggle = !data->toggle;

        data->state = STATE_HEADER_SPACE;

        return 0;

​

    case STATE_HEADER_SPACE:

        if (ev.pulse)

            break;

​

        if (!eq_margin(ev.duration, JVC_HEADER_SPACE, JVC_UNIT / 2))

            break;

​

        data->state = STATE_BIT_PULSE;

        return 0;

​

    case STATE_BIT_PULSE:

        if (!ev.pulse)

            break;

​

        if (!eq_margin(ev.duration, JVC_BIT_PULSE, JVC_UNIT / 2))