1// SPDX-License-Identifier: GPL-2.0
2// ir-sanyo-decoder.c - handle SANYO IR Pulse/Space protocol
3//
4// Copyright (C) 2011 by Mauro Carvalho Chehab
5//
6// This protocol uses the NEC protocol timings. However, data is formatted as:
7// 13 bits Custom Code
8// 13 bits NOT(Custom Code)
9// 8 bits Key data
10// 8 bits NOT(Key data)
11//
12// According with LIRC, this protocol is used on Sanyo, Aiwa and Chinon
13// Information for this protocol is available at the Sanyo LC7461 datasheet.
14
15#include <linux/module.h>
16#include <linux/bitrev.h>
17#include "rc-core-priv.h"
18
19#define SANYO_NBITS (13+13+8+8)
20#define SANYO_UNIT 563 /* us */
21#define SANYO_HEADER_PULSE (16 * SANYO_UNIT)
22#define SANYO_HEADER_SPACE (8 * SANYO_UNIT)
23#define SANYO_BIT_PULSE (1 * SANYO_UNIT)
24#define SANYO_BIT_0_SPACE (1 * SANYO_UNIT)
25#define SANYO_BIT_1_SPACE (3 * SANYO_UNIT)
26#define SANYO_REPEAT_SPACE (150 * SANYO_UNIT)
27#define SANYO_TRAILER_PULSE (1 * SANYO_UNIT)
28#define SANYO_TRAILER_SPACE (10 * SANYO_UNIT) /* in fact, 42 */
29
30enum sanyo_state {
31 STATE_INACTIVE,
32 STATE_HEADER_SPACE,
33 STATE_BIT_PULSE,
34 STATE_BIT_SPACE,
35 STATE_TRAILER_PULSE,
36 STATE_TRAILER_SPACE,
37};
38
39/**
40 * ir_sanyo_decode() - Decode one SANYO pulse or space
41 * @dev: the struct rc_dev descriptor of the device
42 * @ev: the struct ir_raw_event descriptor of the pulse/space
43 *
44 * This function returns -EINVAL if the pulse violates the state machine
45 */
46static int ir_sanyo_decode(struct rc_dev *dev, struct ir_raw_event ev)
47{
48 struct sanyo_dec *data = &dev->raw->sanyo;
49 u32 scancode;
50 u16 address;
51 u8 command, not_command;
52
53 if (!is_timing_event(ev)) {
54 if (ev.overflow) {
55 dev_dbg(&dev->dev, "SANYO event overflow received. reset to state 0\n");
56 data->state = STATE_INACTIVE;
57 }
58 return 0;
59 }
60
61 dev_dbg(&dev->dev, "SANYO decode started at state %d (%uus %s)\n",
62 data->state, ev.duration, TO_STR(ev.pulse));
63
64 switch (data->state) {
65
66 case STATE_INACTIVE:
67 if (!ev.pulse)
68 break;
69
70 if (eq_margin(d1: ev.duration, SANYO_HEADER_PULSE, SANYO_UNIT / 2)) {
71 data->count = 0;
72 data->state = STATE_HEADER_SPACE;
73 return 0;
74 }
75 break;
76
77
78 case STATE_HEADER_SPACE:
79 if (ev.pulse)
80 break;
81
82 if (eq_margin(d1: ev.duration, SANYO_HEADER_SPACE, SANYO_UNIT / 2)) {
83 data->state = STATE_BIT_PULSE;
84 return 0;
85 }
86
87 break;
88
89 case STATE_BIT_PULSE:
90 if (!ev.pulse)
91 break;
92
93 if (!eq_margin(d1: ev.duration, SANYO_BIT_PULSE, SANYO_UNIT / 2))
94 break;
95
96 data->state = STATE_BIT_SPACE;
97 return 0;
98
99 case STATE_BIT_SPACE:
100 if (ev.pulse)
101 break;
102
103 if (!data->count && geq_margin(d1: ev.duration, SANYO_REPEAT_SPACE, SANYO_UNIT / 2)) {
104 rc_repeat(dev);
105 dev_dbg(&dev->dev, "SANYO repeat last key\n");
106 data->state = STATE_INACTIVE;
107 return 0;
108 }
109
110 data->bits <<= 1;
111 if (eq_margin(d1: ev.duration, SANYO_BIT_1_SPACE, SANYO_UNIT / 2))
112 data->bits |= 1;
113 else if (!eq_margin(d1: ev.duration, SANYO_BIT_0_SPACE, SANYO_UNIT / 2))
114 break;
115 data->count++;
116
117 if (data->count == SANYO_NBITS)
118 data->state = STATE_TRAILER_PULSE;
119 else
120 data->state = STATE_BIT_PULSE;
121
122 return 0;
123
124 case STATE_TRAILER_PULSE:
125 if (!ev.pulse)
126 break;
127
128 if (!eq_margin(d1: ev.duration, SANYO_TRAILER_PULSE, SANYO_UNIT / 2))
129 break;
130
131 data->state = STATE_TRAILER_SPACE;
132 return 0;
133
134 case STATE_TRAILER_SPACE:
135 if (ev.pulse)
136 break;
137
138 if (!geq_margin(d1: ev.duration, SANYO_TRAILER_SPACE, SANYO_UNIT / 2))
139 break;
140
141 address = bitrev16((data->bits >> 29) & 0x1fff) >> 3;
142 /* not_address = bitrev16((data->bits >> 16) & 0x1fff) >> 3; */
143 command = bitrev8((data->bits >> 8) & 0xff);
144 not_command = bitrev8((data->bits >> 0) & 0xff);
145
146 if ((command ^ not_command) != 0xff) {
147 dev_dbg(&dev->dev, "SANYO checksum error: received 0x%08llx\n",
148 data->bits);
149 data->state = STATE_INACTIVE;
150 return 0;
151 }
152
153 scancode = address << 8 | command;
154 dev_dbg(&dev->dev, "SANYO scancode: 0x%06x\n", scancode);
155 rc_keydown(dev, protocol: RC_PROTO_SANYO, scancode, toggle: 0);
156 data->state = STATE_INACTIVE;
157 return 0;
158 }
159
160 dev_dbg(&dev->dev, "SANYO decode failed at count %d state %d (%uus %s)\n",
161 data->count, data->state, ev.duration, TO_STR(ev.pulse));
162 data->state = STATE_INACTIVE;
163 return -EINVAL;
164}
165
166static const struct ir_raw_timings_pd ir_sanyo_timings = {
167 .header_pulse = SANYO_HEADER_PULSE,
168 .header_space = SANYO_HEADER_SPACE,
169 .bit_pulse = SANYO_BIT_PULSE,
170 .bit_space[0] = SANYO_BIT_0_SPACE,
171 .bit_space[1] = SANYO_BIT_1_SPACE,
172 .trailer_pulse = SANYO_TRAILER_PULSE,
173 .trailer_space = SANYO_TRAILER_SPACE,
174 .msb_first = 1,
175};
176
177/**
178 * ir_sanyo_encode() - Encode a scancode as a stream of raw events
179 *
180 * @protocol: protocol to encode
181 * @scancode: scancode to encode
182 * @events: array of raw ir events to write into
183 * @max: maximum size of @events
184 *
185 * Returns: The number of events written.
186 * -ENOBUFS if there isn't enough space in the array to fit the
187 * encoding. In this case all @max events will have been written.
188 */
189static int ir_sanyo_encode(enum rc_proto protocol, u32 scancode,
190 struct ir_raw_event *events, unsigned int max)
191{
192 struct ir_raw_event *e = events;
193 int ret;
194 u64 raw;
195
196 raw = ((u64)(bitrev16(scancode >> 8) & 0xfff8) << (8 + 8 + 13 - 3)) |
197 ((u64)(bitrev16(~scancode >> 8) & 0xfff8) << (8 + 8 + 0 - 3)) |
198 ((bitrev8(scancode) & 0xff) << 8) |
199 (bitrev8(~scancode) & 0xff);
200
201 ret = ir_raw_gen_pd(ev: &e, max, timings: &ir_sanyo_timings, SANYO_NBITS, data: raw);
202 if (ret < 0)
203 return ret;
204
205 return e - events;
206}
207
208static struct ir_raw_handler sanyo_handler = {
209 .protocols = RC_PROTO_BIT_SANYO,
210 .decode = ir_sanyo_decode,
211 .encode = ir_sanyo_encode,
212 .carrier = 38000,
213 .min_timeout = SANYO_TRAILER_SPACE,
214};
215
216static int __init ir_sanyo_decode_init(void)
217{
218 ir_raw_handler_register(ir_raw_handler: &sanyo_handler);
219
220 printk(KERN_INFO "IR SANYO protocol handler initialized\n");
221 return 0;
222}
223
224static void __exit ir_sanyo_decode_exit(void)
225{
226 ir_raw_handler_unregister(ir_raw_handler: &sanyo_handler);
227}
228
229module_init(ir_sanyo_decode_init);
230module_exit(ir_sanyo_decode_exit);
231
232MODULE_LICENSE("GPL v2");
233MODULE_AUTHOR("Mauro Carvalho Chehab");
234MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
235MODULE_DESCRIPTION("SANYO IR protocol decoder");
236

source code of linux/drivers/media/rc/ir-sanyo-decoder.c