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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> | |
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 | }; |
37 | ||
bf670f64 DH |
38 | /** |
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; |
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) | |
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; |
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"); |