1 /* ir-jvc-decoder.c - handle JVC IR Pulse/Space protocol
3 * Copyright (C) 2010 by David Härdeman <david@hardeman.nu>
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.
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.
15 #include <linux/bitrev.h>
16 #include "ir-core-priv.h"
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)
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
43 * This function returns -EINVAL if the pulse violates the state machine
45 static int ir_jvc_decode(struct input_dev *input_dev, struct ir_raw_event ev)
47 struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
48 struct jvc_dec *data = &ir_dev->raw->jvc;
50 if (!(ir_dev->raw->enabled_protocols & IR_TYPE_JVC))
54 data->state = STATE_INACTIVE;
58 if (!geq_margin(ev.duration, JVC_UNIT, JVC_UNIT / 2))
61 IR_dprintk(2, "JVC decode started at state %d (%uus %s)\n",
62 data->state, TO_US(ev.duration), TO_STR(ev.pulse));
65 switch (data->state) {
71 if (!eq_margin(ev.duration, JVC_HEADER_PULSE, JVC_UNIT / 2))
76 data->toggle = !data->toggle;
77 data->state = STATE_HEADER_SPACE;
80 case STATE_HEADER_SPACE:
84 if (!eq_margin(ev.duration, JVC_HEADER_SPACE, JVC_UNIT / 2))
87 data->state = STATE_BIT_PULSE;
94 if (!eq_margin(ev.duration, JVC_BIT_PULSE, JVC_UNIT / 2))
97 data->state = STATE_BIT_SPACE;
100 case STATE_BIT_SPACE:
105 if (eq_margin(ev.duration, JVC_BIT_1_SPACE, JVC_UNIT / 2)) {
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);
114 if (data->count == JVC_NBITS)
115 data->state = STATE_TRAILER_PULSE;
117 data->state = STATE_BIT_PULSE;
120 case STATE_TRAILER_PULSE:
124 if (!eq_margin(ev.duration, JVC_TRAILER_PULSE, JVC_UNIT / 2))
127 data->state = STATE_TRAILER_SPACE;
130 case STATE_TRAILER_SPACE:
134 if (!geq_margin(ev.duration, JVC_TRAILER_SPACE, JVC_UNIT / 2))
139 scancode = (bitrev8((data->bits >> 8) & 0xff) << 8) |
140 (bitrev8((data->bits >> 0) & 0xff) << 0);
141 IR_dprintk(1, "JVC scancode 0x%04x\n", scancode);
142 ir_keydown(input_dev, scancode, data->toggle);
144 data->old_bits = data->bits;
145 } else if (data->bits == data->old_bits) {
146 IR_dprintk(1, "JVC repeat\n");
147 ir_repeat(input_dev);
149 IR_dprintk(1, "JVC invalid repeat msg\n");
154 data->state = STATE_CHECK_REPEAT;
157 case STATE_CHECK_REPEAT:
161 if (eq_margin(ev.duration, JVC_HEADER_PULSE, JVC_UNIT / 2))
162 data->state = STATE_INACTIVE;
164 data->state = STATE_BIT_PULSE;
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;
175 static struct ir_raw_handler jvc_handler = {
176 .protocols = IR_TYPE_JVC,
177 .decode = ir_jvc_decode,
180 static int __init ir_jvc_decode_init(void)
182 ir_raw_handler_register(&jvc_handler);
184 printk(KERN_INFO "IR JVC protocol handler initialized\n");
188 static void __exit ir_jvc_decode_exit(void)
190 ir_raw_handler_unregister(&jvc_handler);
193 module_init(ir_jvc_decode_init);
194 module_exit(ir_jvc_decode_exit);
196 MODULE_LICENSE("GPL");
197 MODULE_AUTHOR("David Härdeman <david@hardeman.nu>");
198 MODULE_DESCRIPTION("JVC IR protocol decoder");