Commit | Line | Data |
---|---|---|
1d184b0b JH |
1 | /* ir-sharp-decoder.c - handle Sharp IR Pulse/Space protocol |
2 | * | |
3 | * Copyright (C) 2013-2014 Imagination Technologies Ltd. | |
4 | * | |
5 | * Based on NEC decoder: | |
37e59f87 | 6 | * Copyright (C) 2010 by Mauro Carvalho Chehab |
1d184b0b JH |
7 | * |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation version 2 of the License. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | */ | |
17 | ||
18 | #include <linux/bitrev.h> | |
19 | #include <linux/module.h> | |
20 | #include "rc-core-priv.h" | |
21 | ||
22 | #define SHARP_NBITS 15 | |
23 | #define SHARP_UNIT 40000 /* ns */ | |
24 | #define SHARP_BIT_PULSE (8 * SHARP_UNIT) /* 320us */ | |
25 | #define SHARP_BIT_0_PERIOD (25 * SHARP_UNIT) /* 1ms (680us space) */ | |
26 | #define SHARP_BIT_1_PERIOD (50 * SHARP_UNIT) /* 2ms (1680ms space) */ | |
27 | #define SHARP_ECHO_SPACE (1000 * SHARP_UNIT) /* 40 ms */ | |
28 | #define SHARP_TRAILER_SPACE (125 * SHARP_UNIT) /* 5 ms (even longer) */ | |
29 | ||
30 | enum sharp_state { | |
31 | STATE_INACTIVE, | |
32 | STATE_BIT_PULSE, | |
33 | STATE_BIT_SPACE, | |
34 | STATE_TRAILER_PULSE, | |
35 | STATE_ECHO_SPACE, | |
36 | STATE_TRAILER_SPACE, | |
37 | }; | |
38 | ||
39 | /** | |
40 | * ir_sharp_decode() - Decode one Sharp pulse or space | |
41 | * @dev: the struct rc_dev descriptor of the device | |
42 | * @duration: the struct ir_raw_event descriptor of the pulse/space | |
43 | * | |
44 | * This function returns -EINVAL if the pulse violates the state machine | |
45 | */ | |
46 | static int ir_sharp_decode(struct rc_dev *dev, struct ir_raw_event ev) | |
47 | { | |
48 | struct sharp_dec *data = &dev->raw->sharp; | |
49 | u32 msg, echo, address, command, scancode; | |
50 | ||
1d184b0b JH |
51 | if (!is_timing_event(ev)) { |
52 | if (ev.reset) | |
53 | data->state = STATE_INACTIVE; | |
54 | return 0; | |
55 | } | |
56 | ||
57 | IR_dprintk(2, "Sharp decode started at state %d (%uus %s)\n", | |
58 | data->state, TO_US(ev.duration), TO_STR(ev.pulse)); | |
59 | ||
60 | switch (data->state) { | |
61 | ||
62 | case STATE_INACTIVE: | |
63 | if (!ev.pulse) | |
64 | break; | |
65 | ||
66 | if (!eq_margin(ev.duration, SHARP_BIT_PULSE, | |
67 | SHARP_BIT_PULSE / 2)) | |
68 | break; | |
69 | ||
70 | data->count = 0; | |
71 | data->pulse_len = ev.duration; | |
72 | data->state = STATE_BIT_SPACE; | |
73 | return 0; | |
74 | ||
75 | case STATE_BIT_PULSE: | |
76 | if (!ev.pulse) | |
77 | break; | |
78 | ||
79 | if (!eq_margin(ev.duration, SHARP_BIT_PULSE, | |
80 | SHARP_BIT_PULSE / 2)) | |
81 | break; | |
82 | ||
83 | data->pulse_len = ev.duration; | |
84 | data->state = STATE_BIT_SPACE; | |
85 | return 0; | |
86 | ||
87 | case STATE_BIT_SPACE: | |
88 | if (ev.pulse) | |
89 | break; | |
90 | ||
91 | data->bits <<= 1; | |
92 | if (eq_margin(data->pulse_len + ev.duration, SHARP_BIT_1_PERIOD, | |
93 | SHARP_BIT_PULSE * 2)) | |
94 | data->bits |= 1; | |
95 | else if (!eq_margin(data->pulse_len + ev.duration, | |
96 | SHARP_BIT_0_PERIOD, SHARP_BIT_PULSE * 2)) | |
97 | break; | |
98 | data->count++; | |
99 | ||
100 | if (data->count == SHARP_NBITS || | |
101 | data->count == SHARP_NBITS * 2) | |
102 | data->state = STATE_TRAILER_PULSE; | |
103 | else | |
104 | data->state = STATE_BIT_PULSE; | |
105 | ||
106 | return 0; | |
107 | ||
108 | case STATE_TRAILER_PULSE: | |
109 | if (!ev.pulse) | |
110 | break; | |
111 | ||
112 | if (!eq_margin(ev.duration, SHARP_BIT_PULSE, | |
113 | SHARP_BIT_PULSE / 2)) | |
114 | break; | |
115 | ||
116 | if (data->count == SHARP_NBITS) { | |
117 | /* exp,chk bits should be 1,0 */ | |
1b0621af HK |
118 | if ((data->bits & 0x3) != 0x2 && |
119 | /* DENON variant, both chk bits 0 */ | |
120 | (data->bits & 0x3) != 0x0) | |
1d184b0b JH |
121 | break; |
122 | data->state = STATE_ECHO_SPACE; | |
123 | } else { | |
124 | data->state = STATE_TRAILER_SPACE; | |
125 | } | |
126 | return 0; | |
127 | ||
128 | case STATE_ECHO_SPACE: | |
129 | if (ev.pulse) | |
130 | break; | |
131 | ||
132 | if (!eq_margin(ev.duration, SHARP_ECHO_SPACE, | |
133 | SHARP_ECHO_SPACE / 4)) | |
134 | break; | |
135 | ||
136 | data->state = STATE_BIT_PULSE; | |
137 | ||
138 | return 0; | |
139 | ||
140 | case STATE_TRAILER_SPACE: | |
141 | if (ev.pulse) | |
142 | break; | |
143 | ||
144 | if (!geq_margin(ev.duration, SHARP_TRAILER_SPACE, | |
145 | SHARP_BIT_PULSE / 2)) | |
146 | break; | |
147 | ||
148 | /* Validate - command, ext, chk should be inverted in 2nd */ | |
149 | msg = (data->bits >> 15) & 0x7fff; | |
150 | echo = data->bits & 0x7fff; | |
151 | if ((msg ^ echo) != 0x3ff) { | |
152 | IR_dprintk(1, | |
153 | "Sharp checksum error: received 0x%04x, 0x%04x\n", | |
154 | msg, echo); | |
155 | break; | |
156 | } | |
157 | ||
158 | address = bitrev8((msg >> 7) & 0xf8); | |
159 | command = bitrev8((msg >> 2) & 0xff); | |
160 | ||
161 | scancode = address << 8 | command; | |
162 | IR_dprintk(1, "Sharp scancode 0x%04x\n", scancode); | |
163 | ||
120703f9 | 164 | rc_keydown(dev, RC_TYPE_SHARP, scancode, 0); |
1d184b0b JH |
165 | data->state = STATE_INACTIVE; |
166 | return 0; | |
167 | } | |
168 | ||
169 | IR_dprintk(1, "Sharp decode failed at count %d state %d (%uus %s)\n", | |
170 | data->count, data->state, TO_US(ev.duration), | |
171 | TO_STR(ev.pulse)); | |
172 | data->state = STATE_INACTIVE; | |
173 | return -EINVAL; | |
174 | } | |
175 | ||
176 | static struct ir_raw_handler sharp_handler = { | |
177 | .protocols = RC_BIT_SHARP, | |
178 | .decode = ir_sharp_decode, | |
179 | }; | |
180 | ||
181 | static int __init ir_sharp_decode_init(void) | |
182 | { | |
183 | ir_raw_handler_register(&sharp_handler); | |
184 | ||
185 | pr_info("IR Sharp protocol handler initialized\n"); | |
186 | return 0; | |
187 | } | |
188 | ||
189 | static void __exit ir_sharp_decode_exit(void) | |
190 | { | |
191 | ir_raw_handler_unregister(&sharp_handler); | |
192 | } | |
193 | ||
194 | module_init(ir_sharp_decode_init); | |
195 | module_exit(ir_sharp_decode_exit); | |
196 | ||
197 | MODULE_LICENSE("GPL"); | |
198 | MODULE_AUTHOR("James Hogan <james.hogan@imgtec.com>"); | |
199 | MODULE_DESCRIPTION("Sharp IR protocol decoder"); |