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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, | |
35 | }; | |
36 | ||
bf670f64 DH |
37 | /** |
38 | * ir_jvc_decode() - Decode one JVC pulse or space | |
39 | * @input_dev: the struct input_dev descriptor of the device | |
40 | * @duration: the struct ir_raw_event descriptor of the pulse/space | |
41 | * | |
42 | * This function returns -EINVAL if the pulse violates the state machine | |
43 | */ | |
44 | static int ir_jvc_decode(struct input_dev *input_dev, struct ir_raw_event ev) | |
45 | { | |
bf670f64 | 46 | struct ir_input_dev *ir_dev = input_get_drvdata(input_dev); |
c216369e | 47 | struct jvc_dec *data = &ir_dev->raw->jvc; |
bf670f64 | 48 | |
667c9ebe | 49 | if (!(ir_dev->raw->enabled_protocols & IR_TYPE_JVC)) |
bf670f64 DH |
50 | return 0; |
51 | ||
52 | if (IS_RESET(ev)) { | |
53 | data->state = STATE_INACTIVE; | |
54 | return 0; | |
55 | } | |
56 | ||
57 | if (!geq_margin(ev.duration, JVC_UNIT, JVC_UNIT / 2)) | |
58 | goto out; | |
59 | ||
60 | IR_dprintk(2, "JVC decode started at state %d (%uus %s)\n", | |
61 | data->state, TO_US(ev.duration), TO_STR(ev.pulse)); | |
62 | ||
63 | switch (data->state) { | |
64 | ||
65 | case STATE_INACTIVE: | |
66 | if (!ev.pulse) | |
67 | break; | |
68 | ||
69 | if (!eq_margin(ev.duration, JVC_HEADER_PULSE, JVC_UNIT / 2)) | |
70 | break; | |
71 | ||
72 | data->count = 0; | |
73 | data->first = true; | |
74 | data->toggle = !data->toggle; | |
75 | data->state = STATE_HEADER_SPACE; | |
76 | return 0; | |
77 | ||
78 | case STATE_HEADER_SPACE: | |
79 | if (ev.pulse) | |
80 | break; | |
81 | ||
82 | if (!eq_margin(ev.duration, JVC_HEADER_SPACE, JVC_UNIT / 2)) | |
83 | break; | |
84 | ||
85 | data->state = STATE_BIT_PULSE; | |
86 | return 0; | |
87 | ||
88 | case STATE_BIT_PULSE: | |
89 | if (!ev.pulse) | |
90 | break; | |
91 | ||
92 | if (!eq_margin(ev.duration, JVC_BIT_PULSE, JVC_UNIT / 2)) | |
93 | break; | |
94 | ||
95 | data->state = STATE_BIT_SPACE; | |
96 | return 0; | |
97 | ||
98 | case STATE_BIT_SPACE: | |
99 | if (ev.pulse) | |
100 | break; | |
101 | ||
c216369e | 102 | data->bits <<= 1; |
bf670f64 | 103 | if (eq_margin(ev.duration, JVC_BIT_1_SPACE, JVC_UNIT / 2)) { |
c216369e | 104 | data->bits |= 1; |
bf670f64 DH |
105 | decrease_duration(&ev, JVC_BIT_1_SPACE); |
106 | } else if (eq_margin(ev.duration, JVC_BIT_0_SPACE, JVC_UNIT / 2)) | |
107 | decrease_duration(&ev, JVC_BIT_0_SPACE); | |
108 | else | |
109 | break; | |
110 | data->count++; | |
111 | ||
112 | if (data->count == JVC_NBITS) | |
113 | data->state = STATE_TRAILER_PULSE; | |
114 | else | |
115 | data->state = STATE_BIT_PULSE; | |
116 | return 0; | |
117 | ||
118 | case STATE_TRAILER_PULSE: | |
119 | if (!ev.pulse) | |
120 | break; | |
121 | ||
122 | if (!eq_margin(ev.duration, JVC_TRAILER_PULSE, JVC_UNIT / 2)) | |
123 | break; | |
124 | ||
125 | data->state = STATE_TRAILER_SPACE; | |
126 | return 0; | |
127 | ||
128 | case STATE_TRAILER_SPACE: | |
129 | if (ev.pulse) | |
130 | break; | |
131 | ||
132 | if (!geq_margin(ev.duration, JVC_TRAILER_SPACE, JVC_UNIT / 2)) | |
133 | break; | |
134 | ||
135 | if (data->first) { | |
136 | u32 scancode; | |
c216369e DH |
137 | scancode = (bitrev8((data->bits >> 8) & 0xff) << 8) | |
138 | (bitrev8((data->bits >> 0) & 0xff) << 0); | |
bf670f64 DH |
139 | IR_dprintk(1, "JVC scancode 0x%04x\n", scancode); |
140 | ir_keydown(input_dev, scancode, data->toggle); | |
141 | data->first = false; | |
c216369e DH |
142 | data->old_bits = data->bits; |
143 | } else if (data->bits == data->old_bits) { | |
bf670f64 DH |
144 | IR_dprintk(1, "JVC repeat\n"); |
145 | ir_repeat(input_dev); | |
146 | } else { | |
147 | IR_dprintk(1, "JVC invalid repeat msg\n"); | |
148 | break; | |
149 | } | |
150 | ||
151 | data->count = 0; | |
152 | data->state = STATE_BIT_PULSE; | |
153 | return 0; | |
154 | } | |
155 | ||
156 | out: | |
157 | IR_dprintk(1, "JVC decode failed at state %d (%uus %s)\n", | |
158 | data->state, TO_US(ev.duration), TO_STR(ev.pulse)); | |
159 | data->state = STATE_INACTIVE; | |
160 | return -EINVAL; | |
161 | } | |
162 | ||
bf670f64 | 163 | static struct ir_raw_handler jvc_handler = { |
667c9ebe | 164 | .protocols = IR_TYPE_JVC, |
bf670f64 | 165 | .decode = ir_jvc_decode, |
bf670f64 DH |
166 | }; |
167 | ||
168 | static int __init ir_jvc_decode_init(void) | |
169 | { | |
170 | ir_raw_handler_register(&jvc_handler); | |
171 | ||
172 | printk(KERN_INFO "IR JVC protocol handler initialized\n"); | |
173 | return 0; | |
174 | } | |
175 | ||
176 | static void __exit ir_jvc_decode_exit(void) | |
177 | { | |
178 | ir_raw_handler_unregister(&jvc_handler); | |
179 | } | |
180 | ||
181 | module_init(ir_jvc_decode_init); | |
182 | module_exit(ir_jvc_decode_exit); | |
183 | ||
184 | MODULE_LICENSE("GPL"); | |
185 | MODULE_AUTHOR("David Härdeman <david@hardeman.nu>"); | |
186 | MODULE_DESCRIPTION("JVC IR protocol decoder"); |