summaryrefslogtreecommitdiffstats
path: root/drivers/media/rc/ir-sanyo-decoder.c
blob: eb715f04dc27954af4bf458bbdcb6bd2a25e3bdc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
/* ir-sanyo-decoder.c - handle SANYO IR Pulse/Space protocol
 *
 * Copyright (C) 2011 by Mauro Carvalho Chehab
 *
 * 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, command, not_command;

	if (!rc_protocols_enabled(dev, RC_BIT_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_BIT_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");
MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
MODULE_DESCRIPTION("SANYO IR protocol decoder");
OpenPOWER on IntegriCloud