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Merge tag 'for-v4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux...
[mirror_ubuntu-bionic-kernel.git] / drivers / media / rc / ir-jvc-decoder.c
CommitLineData
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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>
7a707b89 16#include <linux/module.h>
f62de675 17#include "rc-core-priv.h"
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18
19#define JVC_NBITS 16 /* dev(8) + func(8) */
20#define JVC_UNIT 525000 /* ns */
21#define JVC_HEADER_PULSE (16 * JVC_UNIT) /* lack of header -> repeat */
22#define JVC_HEADER_SPACE (8 * JVC_UNIT)
23#define JVC_BIT_PULSE (1 * JVC_UNIT)
24#define JVC_BIT_0_SPACE (1 * JVC_UNIT)
25#define JVC_BIT_1_SPACE (3 * JVC_UNIT)
26#define JVC_TRAILER_PULSE (1 * JVC_UNIT)
27#define JVC_TRAILER_SPACE (35 * JVC_UNIT)
28
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29enum jvc_state {
30 STATE_INACTIVE,
31 STATE_HEADER_SPACE,
32 STATE_BIT_PULSE,
33 STATE_BIT_SPACE,
34 STATE_TRAILER_PULSE,
35 STATE_TRAILER_SPACE,
39b2c068 36 STATE_CHECK_REPEAT,
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37};
38
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39/**
40 * ir_jvc_decode() - Decode one JVC pulse or space
d8b4b582 41 * @dev: the struct rc_dev descriptor of the device
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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 */
d8b4b582 46static int ir_jvc_decode(struct rc_dev *dev, struct ir_raw_event ev)
bf670f64 47{
d8b4b582 48 struct jvc_dec *data = &dev->raw->jvc;
bf670f64 49
4651918a
ML
50 if (!is_timing_event(ev)) {
51 if (ev.reset)
52 data->state = STATE_INACTIVE;
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53 return 0;
54 }
55
56 if (!geq_margin(ev.duration, JVC_UNIT, JVC_UNIT / 2))
57 goto out;
58
59 IR_dprintk(2, "JVC decode started at state %d (%uus %s)\n",
60 data->state, TO_US(ev.duration), TO_STR(ev.pulse));
61
39b2c068 62again:
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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;
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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;
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137 scancode = (bitrev8((data->bits >> 8) & 0xff) << 8) |
138 (bitrev8((data->bits >> 0) & 0xff) << 0);
bf670f64 139 IR_dprintk(1, "JVC scancode 0x%04x\n", scancode);
6d741bfe 140 rc_keydown(dev, RC_PROTO_JVC, scancode, data->toggle);
bf670f64 141 data->first = false;
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142 data->old_bits = data->bits;
143 } else if (data->bits == data->old_bits) {
bf670f64 144 IR_dprintk(1, "JVC repeat\n");
ca86674b 145 rc_repeat(dev);
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146 } else {
147 IR_dprintk(1, "JVC invalid repeat msg\n");
148 break;
149 }
150
151 data->count = 0;
39b2c068 152 data->state = STATE_CHECK_REPEAT;
bf670f64 153 return 0;
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154
155 case STATE_CHECK_REPEAT:
156 if (!ev.pulse)
157 break;
158
159 if (eq_margin(ev.duration, JVC_HEADER_PULSE, JVC_UNIT / 2))
160 data->state = STATE_INACTIVE;
161 else
162 data->state = STATE_BIT_PULSE;
163 goto again;
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164 }
165
166out:
167 IR_dprintk(1, "JVC decode failed at state %d (%uus %s)\n",
168 data->state, TO_US(ev.duration), TO_STR(ev.pulse));
169 data->state = STATE_INACTIVE;
170 return -EINVAL;
171}
172
d8a2ae5c
SY
173static const struct ir_raw_timings_pd ir_jvc_timings = {
174 .header_pulse = JVC_HEADER_PULSE,
175 .header_space = JVC_HEADER_SPACE,
176 .bit_pulse = JVC_BIT_PULSE,
177 .bit_space[0] = JVC_BIT_0_SPACE,
178 .bit_space[1] = JVC_BIT_1_SPACE,
179 .trailer_pulse = JVC_TRAILER_PULSE,
180 .trailer_space = JVC_TRAILER_SPACE,
181 .msb_first = 1,
182};
183
184/**
185 * ir_jvc_encode() - Encode a scancode as a stream of raw events
186 *
187 * @protocol: protocol to encode
188 * @scancode: scancode to encode
189 * @events: array of raw ir events to write into
190 * @max: maximum size of @events
191 *
192 * Returns: The number of events written.
193 * -ENOBUFS if there isn't enough space in the array to fit the
194 * encoding. In this case all @max events will have been written.
195 */
6d741bfe 196static int ir_jvc_encode(enum rc_proto protocol, u32 scancode,
d8a2ae5c
SY
197 struct ir_raw_event *events, unsigned int max)
198{
199 struct ir_raw_event *e = events;
200 int ret;
201 u32 raw = (bitrev8((scancode >> 8) & 0xff) << 8) |
202 (bitrev8((scancode >> 0) & 0xff) << 0);
203
204 ret = ir_raw_gen_pd(&e, max, &ir_jvc_timings, JVC_NBITS, raw);
205 if (ret < 0)
206 return ret;
207
208 return e - events;
209}
210
bf670f64 211static struct ir_raw_handler jvc_handler = {
6d741bfe 212 .protocols = RC_PROTO_BIT_JVC,
bf670f64 213 .decode = ir_jvc_decode,
d8a2ae5c 214 .encode = ir_jvc_encode,
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DH
215};
216
217static int __init ir_jvc_decode_init(void)
218{
219 ir_raw_handler_register(&jvc_handler);
220
221 printk(KERN_INFO "IR JVC protocol handler initialized\n");
222 return 0;
223}
224
225static void __exit ir_jvc_decode_exit(void)
226{
227 ir_raw_handler_unregister(&jvc_handler);
228}
229
230module_init(ir_jvc_decode_init);
231module_exit(ir_jvc_decode_exit);
232
233MODULE_LICENSE("GPL");
234MODULE_AUTHOR("David Härdeman <david@hardeman.nu>");
235MODULE_DESCRIPTION("JVC IR protocol decoder");