[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / media / rc / ir-jvc-decoder.c

/* 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 "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
 * @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_jvc_decode(struct rc_dev *dev, struct ir_raw_event ev)
{
	struct jvc_dec *data = &dev->raw->jvc;

	if (!(dev->raw->enabled_protocols & RC_TYPE_JVC))
		return 0;

	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;

	IR_dprintk(2, "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))
			break;

		data->state = STATE_BIT_SPACE;
		return 0;

	case STATE_BIT_SPACE:
		if (ev.pulse)
			break;

		data->bits <<= 1;
		if (eq_margin(ev.duration, JVC_BIT_1_SPACE, JVC_UNIT / 2)) {
			data->bits |= 1;
			decrease_duration(&ev, JVC_BIT_1_SPACE);
		} else if (eq_margin(ev.duration, JVC_BIT_0_SPACE, JVC_UNIT / 2))
			decrease_duration(&ev, JVC_BIT_0_SPACE);
		else
			break;
		data->count++;

		if (data->count == JVC_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, JVC_TRAILER_PULSE, JVC_UNIT / 2))
			break;

		data->state = STATE_TRAILER_SPACE;
		return 0;

	case STATE_TRAILER_SPACE:
		if (ev.pulse)
			break;

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

		if (data->first) {
			u32 scancode;
			scancode = (bitrev8((data->bits >> 8) & 0xff) << 8) |
				   (bitrev8((data->bits >> 0) & 0xff) << 0);
			IR_dprintk(1, "JVC scancode 0x%04x\n", scancode);
			rc_keydown(dev, scancode, data->toggle);
			data->first = false;
			data->old_bits = data->bits;
		} else if (data->bits == data->old_bits) {
			IR_dprintk(1, "JVC repeat\n");
			rc_repeat(dev);
		} else {
			IR_dprintk(1, "JVC invalid repeat msg\n");
			break;
		}

		data->count = 0;
		data->state = STATE_CHECK_REPEAT;
		return 0;

	case STATE_CHECK_REPEAT:
		if (!ev.pulse)
			break;

		if (eq_margin(ev.duration, JVC_HEADER_PULSE, JVC_UNIT / 2))
			data->state = STATE_INACTIVE;
  else
			data->state = STATE_BIT_PULSE;
		goto again;
	}

out:
	IR_dprintk(1, "JVC decode failed at state %d (%uus %s)\n",
		   data->state, TO_US(ev.duration), TO_STR(ev.pulse));
	data->state = STATE_INACTIVE;
	return -EINVAL;
}

static struct ir_raw_handler jvc_handler = {
	.protocols	= RC_TYPE_JVC,
	.decode		= ir_jvc_decode,
};

static int __init ir_jvc_decode_init(void)
{
	ir_raw_handler_register(&jvc_handler);

	printk(KERN_INFO "IR JVC protocol handler initialized\n");
	return 0;
}

static void __exit ir_jvc_decode_exit(void)
{
	ir_raw_handler_unregister(&jvc_handler);
}

module_init(ir_jvc_decode_init);
module_exit(ir_jvc_decode_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Härdeman <david@hardeman.nu>");
MODULE_DESCRIPTION("JVC IR protocol decoder");
Commit	Line	Data
bf670f64 DH	1	/* ir-jvc-decoder.c - handle JVC IR Pulse/Space protocol
	2	*
	3	* Copyright (C) 2010 by David Härdeman <david@hardeman.nu>
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License as published by
	7	* the Free Software Foundation version 2 of the License.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*/
	14
	15	#include <linux/bitrev.h>
f62de675	16	#include "rc-core-priv.h"
bf670f64 DH	17
	18	#define JVC_NBITS 16 /* dev(8) + func(8) */
	19	#define JVC_UNIT 525000 /* ns */
	20	#define JVC_HEADER_PULSE (16 * JVC_UNIT) /* lack of header -> repeat */
	21	#define JVC_HEADER_SPACE (8 * JVC_UNIT)
	22	#define JVC_BIT_PULSE (1 * JVC_UNIT)
	23	#define JVC_BIT_0_SPACE (1 * JVC_UNIT)
	24	#define JVC_BIT_1_SPACE (3 * JVC_UNIT)
	25	#define JVC_TRAILER_PULSE (1 * JVC_UNIT)
	26	#define JVC_TRAILER_SPACE (35 * JVC_UNIT)
	27
bf670f64 DH	28	enum jvc_state {
	29	STATE_INACTIVE,
	30	STATE_HEADER_SPACE,
	31	STATE_BIT_PULSE,
	32	STATE_BIT_SPACE,
	33	STATE_TRAILER_PULSE,
	34	STATE_TRAILER_SPACE,
39b2c068	35	STATE_CHECK_REPEAT,
bf670f64 DH	36	};
bf670f64 DH	37
bf670f64 DH	38	/**
bf670f64 DH	39	* ir_jvc_decode() - Decode one JVC pulse or space
d8b4b582	40	* @dev: the struct rc_dev descriptor of the device
bf670f64 DH	41	* @duration: the struct ir_raw_event descriptor of the pulse/space
	42	*
	43	* This function returns -EINVAL if the pulse violates the state machine
	44	*/
d8b4b582	45	static int ir_jvc_decode(struct rc_dev *dev, struct ir_raw_event ev)
bf670f64	46	{
d8b4b582	47	struct jvc_dec *data = &dev->raw->jvc;
bf670f64	48
52b66144	49	if (!(dev->raw->enabled_protocols & RC_TYPE_JVC))
bf670f64 DH	50	return 0;
bf670f64 DH	51
4651918a ML	52	if (!is_timing_event(ev)) {
	53	if (ev.reset)
	54	data->state = STATE_INACTIVE;
bf670f64 DH	55	return 0;
	56	}
	57
	58	if (!geq_margin(ev.duration, JVC_UNIT, JVC_UNIT / 2))
	59	goto out;
	60
	61	IR_dprintk(2, "JVC decode started at state %d (%uus %s)\n",
	62	data->state, TO_US(ev.duration), TO_STR(ev.pulse));
	63
39b2c068	64	again:
bf670f64 DH	65	switch (data->state) {
	66
	67	case STATE_INACTIVE:
	68	if (!ev.pulse)
	69	break;
	70
	71	if (!eq_margin(ev.duration, JVC_HEADER_PULSE, JVC_UNIT / 2))
	72	break;
	73
	74	data->count = 0;
	75	data->first = true;
	76	data->toggle = !data->toggle;
	77	data->state = STATE_HEADER_SPACE;
	78	return 0;
	79
	80	case STATE_HEADER_SPACE:
	81	if (ev.pulse)
	82	break;
	83
	84	if (!eq_margin(ev.duration, JVC_HEADER_SPACE, JVC_UNIT / 2))
	85	break;
	86
	87	data->state = STATE_BIT_PULSE;
	88	return 0;
	89
	90	case STATE_BIT_PULSE:
	91	if (!ev.pulse)
	92	break;
	93
	94	if (!eq_margin(ev.duration, JVC_BIT_PULSE, JVC_UNIT / 2))
	95	break;
	96
	97	data->state = STATE_BIT_SPACE;
	98	return 0;
	99
	100	case STATE_BIT_SPACE:
	101	if (ev.pulse)
	102	break;
	103
c216369e	104	data->bits <<= 1;
bf670f64	105	if (eq_margin(ev.duration, JVC_BIT_1_SPACE, JVC_UNIT / 2)) {
c216369e	106	data->bits \|= 1;
bf670f64 DH	107	decrease_duration(&ev, JVC_BIT_1_SPACE);
	108	} else if (eq_margin(ev.duration, JVC_BIT_0_SPACE, JVC_UNIT / 2))
	109	decrease_duration(&ev, JVC_BIT_0_SPACE);
	110	else
	111	break;
	112	data->count++;
	113
	114	if (data->count == JVC_NBITS)
	115	data->state = STATE_TRAILER_PULSE;
	116	else
	117	data->state = STATE_BIT_PULSE;
	118	return 0;
	119
	120	case STATE_TRAILER_PULSE:
	121	if (!ev.pulse)
	122	break;
	123
	124	if (!eq_margin(ev.duration, JVC_TRAILER_PULSE, JVC_UNIT / 2))
	125	break;
	126
	127	data->state = STATE_TRAILER_SPACE;
	128	return 0;
	129
	130	case STATE_TRAILER_SPACE:
	131	if (ev.pulse)
	132	break;
	133
	134	if (!geq_margin(ev.duration, JVC_TRAILER_SPACE, JVC_UNIT / 2))
	135	break;
	136
	137	if (data->first) {
	138	u32 scancode;
c216369e DH	139	scancode = (bitrev8((data->bits >> 8) & 0xff) << 8) \|
c216369e DH	140	(bitrev8((data->bits >> 0) & 0xff) << 0);
bf670f64	141	IR_dprintk(1, "JVC scancode 0x%04x\n", scancode);
ca86674b	142	rc_keydown(dev, scancode, data->toggle);
bf670f64	143	data->first = false;
c216369e DH	144	data->old_bits = data->bits;
c216369e DH	145	} else if (data->bits == data->old_bits) {
bf670f64	146	IR_dprintk(1, "JVC repeat\n");
ca86674b	147	rc_repeat(dev);
bf670f64 DH	148	} else {
	149	IR_dprintk(1, "JVC invalid repeat msg\n");
	150	break;
	151	}
	152
	153	data->count = 0;
39b2c068	154	data->state = STATE_CHECK_REPEAT;
bf670f64	155	return 0;
39b2c068 ML	156
	157	case STATE_CHECK_REPEAT:
	158	if (!ev.pulse)
	159	break;
	160
	161	if (eq_margin(ev.duration, JVC_HEADER_PULSE, JVC_UNIT / 2))
	162	data->state = STATE_INACTIVE;
	163	else
	164	data->state = STATE_BIT_PULSE;
	165	goto again;
bf670f64 DH	166	}
	167
	168	out:
	169	IR_dprintk(1, "JVC decode failed at state %d (%uus %s)\n",
	170	data->state, TO_US(ev.duration), TO_STR(ev.pulse));
	171	data->state = STATE_INACTIVE;
	172	return -EINVAL;
	173	}
	174
bf670f64	175	static struct ir_raw_handler jvc_handler = {
52b66144	176	.protocols = RC_TYPE_JVC,
bf670f64	177	.decode = ir_jvc_decode,
bf670f64 DH	178	};
	179
	180	static int __init ir_jvc_decode_init(void)
	181	{
	182	ir_raw_handler_register(&jvc_handler);
	183
	184	printk(KERN_INFO "IR JVC protocol handler initialized\n");
	185	return 0;
	186	}
	187
	188	static void __exit ir_jvc_decode_exit(void)
	189	{
	190	ir_raw_handler_unregister(&jvc_handler);
	191	}
	192
	193	module_init(ir_jvc_decode_init);
	194	module_exit(ir_jvc_decode_exit);
	195
	196	MODULE_LICENSE("GPL");
	197	MODULE_AUTHOR("David Härdeman <david@hardeman.nu>");
	198	MODULE_DESCRIPTION("JVC IR protocol decoder");