[net-next-2.6.git] / drivers / media / IR / 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 "ir-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
 * @input_dev:	the struct input_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 input_dev *input_dev, struct ir_raw_event ev)
{
	struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
	struct jvc_dec *data = &ir_dev->raw->jvc;

	if (!(ir_dev->raw->enabled_protocols & IR_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);
			ir_keydown(input_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");
			ir_repeat(input_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	= IR_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>
	16	#include "ir-core-priv.h"
	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	/**
	39	* ir_jvc_decode() - Decode one JVC pulse or space
	40	* @input_dev: the struct input_dev descriptor of the device
	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	*/
	45	static int ir_jvc_decode(struct input_dev *input_dev, struct ir_raw_event ev)
	46	{
bf670f64	47	struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
c216369e	48	struct jvc_dec *data = &ir_dev->raw->jvc;
bf670f64	49
667c9ebe	50	if (!(ir_dev->raw->enabled_protocols & IR_TYPE_JVC))
bf670f64 DH	51	return 0;
bf670f64 DH	52
4651918a ML	53	if (!is_timing_event(ev)) {
	54	if (ev.reset)
	55	data->state = STATE_INACTIVE;
bf670f64 DH	56	return 0;
	57	}
	58
	59	if (!geq_margin(ev.duration, JVC_UNIT, JVC_UNIT / 2))
	60	goto out;
	61
	62	IR_dprintk(2, "JVC decode started at state %d (%uus %s)\n",
	63	data->state, TO_US(ev.duration), TO_STR(ev.pulse));
	64
39b2c068	65	again:
bf670f64 DH	66	switch (data->state) {
	67
	68	case STATE_INACTIVE:
	69	if (!ev.pulse)
	70	break;
	71
	72	if (!eq_margin(ev.duration, JVC_HEADER_PULSE, JVC_UNIT / 2))
	73	break;
	74
	75	data->count = 0;
	76	data->first = true;
	77	data->toggle = !data->toggle;
	78	data->state = STATE_HEADER_SPACE;
	79	return 0;
	80
	81	case STATE_HEADER_SPACE:
	82	if (ev.pulse)
	83	break;
	84
	85	if (!eq_margin(ev.duration, JVC_HEADER_SPACE, JVC_UNIT / 2))
	86	break;
	87
	88	data->state = STATE_BIT_PULSE;
	89	return 0;
	90
	91	case STATE_BIT_PULSE:
	92	if (!ev.pulse)
	93	break;
	94
	95	if (!eq_margin(ev.duration, JVC_BIT_PULSE, JVC_UNIT / 2))
	96	break;
	97
	98	data->state = STATE_BIT_SPACE;
	99	return 0;
	100
	101	case STATE_BIT_SPACE:
	102	if (ev.pulse)
	103	break;
	104
c216369e	105	data->bits <<= 1;
bf670f64	106	if (eq_margin(ev.duration, JVC_BIT_1_SPACE, JVC_UNIT / 2)) {
c216369e	107	data->bits \|= 1;
bf670f64 DH	108	decrease_duration(&ev, JVC_BIT_1_SPACE);
	109	} else if (eq_margin(ev.duration, JVC_BIT_0_SPACE, JVC_UNIT / 2))
	110	decrease_duration(&ev, JVC_BIT_0_SPACE);
	111	else
	112	break;
	113	data->count++;
	114
	115	if (data->count == JVC_NBITS)
	116	data->state = STATE_TRAILER_PULSE;
	117	else
	118	data->state = STATE_BIT_PULSE;
	119	return 0;
	120
	121	case STATE_TRAILER_PULSE:
	122	if (!ev.pulse)
	123	break;
	124
	125	if (!eq_margin(ev.duration, JVC_TRAILER_PULSE, JVC_UNIT / 2))
	126	break;
	127
	128	data->state = STATE_TRAILER_SPACE;
	129	return 0;
	130
	131	case STATE_TRAILER_SPACE:
	132	if (ev.pulse)
	133	break;
	134
	135	if (!geq_margin(ev.duration, JVC_TRAILER_SPACE, JVC_UNIT / 2))
	136	break;
	137
	138	if (data->first) {
	139	u32 scancode;
c216369e DH	140	scancode = (bitrev8((data->bits >> 8) & 0xff) << 8) \|
c216369e DH	141	(bitrev8((data->bits >> 0) & 0xff) << 0);
bf670f64 DH	142	IR_dprintk(1, "JVC scancode 0x%04x\n", scancode);
	143	ir_keydown(input_dev, scancode, data->toggle);
	144	data->first = false;
c216369e DH	145	data->old_bits = data->bits;
c216369e DH	146	} else if (data->bits == data->old_bits) {
bf670f64 DH	147	IR_dprintk(1, "JVC repeat\n");
	148	ir_repeat(input_dev);
	149	} else {
	150	IR_dprintk(1, "JVC invalid repeat msg\n");
	151	break;
	152	}
	153
	154	data->count = 0;
39b2c068	155	data->state = STATE_CHECK_REPEAT;
bf670f64	156	return 0;
39b2c068 ML	157
	158	case STATE_CHECK_REPEAT:
	159	if (!ev.pulse)
	160	break;
	161
	162	if (eq_margin(ev.duration, JVC_HEADER_PULSE, JVC_UNIT / 2))
	163	data->state = STATE_INACTIVE;
	164	else
	165	data->state = STATE_BIT_PULSE;
	166	goto again;
bf670f64 DH	167	}
	168
	169	out:
	170	IR_dprintk(1, "JVC decode failed at state %d (%uus %s)\n",
	171	data->state, TO_US(ev.duration), TO_STR(ev.pulse));
	172	data->state = STATE_INACTIVE;
	173	return -EINVAL;
	174	}
	175
bf670f64	176	static struct ir_raw_handler jvc_handler = {
667c9ebe	177	.protocols = IR_TYPE_JVC,
bf670f64	178	.decode = ir_jvc_decode,
bf670f64 DH	179	};
	180
	181	static int __init ir_jvc_decode_init(void)
	182	{
	183	ir_raw_handler_register(&jvc_handler);
	184
	185	printk(KERN_INFO "IR JVC protocol handler initialized\n");
	186	return 0;
	187	}
	188
	189	static void __exit ir_jvc_decode_exit(void)
	190	{
	191	ir_raw_handler_unregister(&jvc_handler);
	192	}
	193
	194	module_init(ir_jvc_decode_init);
	195	module_exit(ir_jvc_decode_exit);
	196
	197	MODULE_LICENSE("GPL");
	198	MODULE_AUTHOR("David Härdeman <david@hardeman.nu>");
	199	MODULE_DESCRIPTION("JVC IR protocol decoder");