1// SPDX-License-Identifier: GPL-2.0-only
2/* ir-sony-decoder.c - handle Sony IR Pulse/Space protocol
3 *
4 * Copyright (C) 2010 by David Härdeman <david@hardeman.nu>
5 */
6
7#include <linux/bitrev.h>
8#include <linux/module.h>
9#include "rc-core-priv.h"
10
11#define SONY_UNIT 600 /* us */
12#define SONY_HEADER_PULSE (4 * SONY_UNIT)
13#define SONY_HEADER_SPACE (1 * SONY_UNIT)
14#define SONY_BIT_0_PULSE (1 * SONY_UNIT)
15#define SONY_BIT_1_PULSE (2 * SONY_UNIT)
16#define SONY_BIT_SPACE (1 * SONY_UNIT)
17#define SONY_TRAILER_SPACE (10 * SONY_UNIT) /* minimum */
18
19enum sony_state {
20 STATE_INACTIVE,
21 STATE_HEADER_SPACE,
22 STATE_BIT_PULSE,
23 STATE_BIT_SPACE,
24 STATE_FINISHED,
25};
26
27/**
28 * ir_sony_decode() - Decode one Sony pulse or space
29 * @dev: the struct rc_dev descriptor of the device
30 * @ev: the struct ir_raw_event descriptor of the pulse/space
31 *
32 * This function returns -EINVAL if the pulse violates the state machine
33 */
34static int ir_sony_decode(struct rc_dev *dev, struct ir_raw_event ev)
35{
36 struct sony_dec *data = &dev->raw->sony;
37 enum rc_proto protocol;
38 u32 scancode;
39 u8 device, subdevice, function;
40
41 if (!is_timing_event(ev)) {
42 if (ev.overflow)
43 data->state = STATE_INACTIVE;
44 return 0;
45 }
46
47 if (!geq_margin(d1: ev.duration, SONY_UNIT, SONY_UNIT / 2))
48 goto out;
49
50 dev_dbg(&dev->dev, "Sony decode started at state %d (%uus %s)\n",
51 data->state, ev.duration, TO_STR(ev.pulse));
52
53 switch (data->state) {
54
55 case STATE_INACTIVE:
56 if (!ev.pulse)
57 break;
58
59 if (!eq_margin(d1: ev.duration, SONY_HEADER_PULSE, SONY_UNIT / 2))
60 break;
61
62 data->count = 0;
63 data->state = STATE_HEADER_SPACE;
64 return 0;
65
66 case STATE_HEADER_SPACE:
67 if (ev.pulse)
68 break;
69
70 if (!eq_margin(d1: ev.duration, SONY_HEADER_SPACE, SONY_UNIT / 2))
71 break;
72
73 data->state = STATE_BIT_PULSE;
74 return 0;
75
76 case STATE_BIT_PULSE:
77 if (!ev.pulse)
78 break;
79
80 data->bits <<= 1;
81 if (eq_margin(d1: ev.duration, SONY_BIT_1_PULSE, SONY_UNIT / 2))
82 data->bits |= 1;
83 else if (!eq_margin(d1: ev.duration, SONY_BIT_0_PULSE, SONY_UNIT / 2))
84 break;
85
86 data->count++;
87 data->state = STATE_BIT_SPACE;
88 return 0;
89
90 case STATE_BIT_SPACE:
91 if (ev.pulse)
92 break;
93
94 if (!geq_margin(d1: ev.duration, SONY_BIT_SPACE, SONY_UNIT / 2))
95 break;
96
97 decrease_duration(ev: &ev, SONY_BIT_SPACE);
98
99 if (!geq_margin(d1: ev.duration, SONY_UNIT, SONY_UNIT / 2)) {
100 data->state = STATE_BIT_PULSE;
101 return 0;
102 }
103
104 data->state = STATE_FINISHED;
105 fallthrough;
106
107 case STATE_FINISHED:
108 if (ev.pulse)
109 break;
110
111 if (!geq_margin(d1: ev.duration, SONY_TRAILER_SPACE, SONY_UNIT / 2))
112 break;
113
114 switch (data->count) {
115 case 12:
116 if (!(dev->enabled_protocols & RC_PROTO_BIT_SONY12))
117 goto finish_state_machine;
118
119 device = bitrev8((data->bits << 3) & 0xF8);
120 subdevice = 0;
121 function = bitrev8((data->bits >> 4) & 0xFE);
122 protocol = RC_PROTO_SONY12;
123 break;
124 case 15:
125 if (!(dev->enabled_protocols & RC_PROTO_BIT_SONY15))
126 goto finish_state_machine;
127
128 device = bitrev8((data->bits >> 0) & 0xFF);
129 subdevice = 0;
130 function = bitrev8((data->bits >> 7) & 0xFE);
131 protocol = RC_PROTO_SONY15;
132 break;
133 case 20:
134 if (!(dev->enabled_protocols & RC_PROTO_BIT_SONY20))
135 goto finish_state_machine;
136
137 device = bitrev8((data->bits >> 5) & 0xF8);
138 subdevice = bitrev8((data->bits >> 0) & 0xFF);
139 function = bitrev8((data->bits >> 12) & 0xFE);
140 protocol = RC_PROTO_SONY20;
141 break;
142 default:
143 dev_dbg(&dev->dev, "Sony invalid bitcount %u\n",
144 data->count);
145 goto out;
146 }
147
148 scancode = device << 16 | subdevice << 8 | function;
149 dev_dbg(&dev->dev, "Sony(%u) scancode 0x%05x\n", data->count,
150 scancode);
151 rc_keydown(dev, protocol, scancode, toggle: 0);
152 goto finish_state_machine;
153 }
154
155out:
156 dev_dbg(&dev->dev, "Sony decode failed at state %d (%uus %s)\n",
157 data->state, ev.duration, TO_STR(ev.pulse));
158 data->state = STATE_INACTIVE;
159 return -EINVAL;
160
161finish_state_machine:
162 data->state = STATE_INACTIVE;
163 return 0;
164}
165
166static const struct ir_raw_timings_pl ir_sony_timings = {
167 .header_pulse = SONY_HEADER_PULSE,
168 .bit_space = SONY_BIT_SPACE,
169 .bit_pulse[0] = SONY_BIT_0_PULSE,
170 .bit_pulse[1] = SONY_BIT_1_PULSE,
171 .trailer_space = SONY_TRAILER_SPACE + SONY_BIT_SPACE,
172 .msb_first = 0,
173};
174
175/**
176 * ir_sony_encode() - Encode a scancode as a stream of raw events
177 *
178 * @protocol: protocol to encode
179 * @scancode: scancode to encode
180 * @events: array of raw ir events to write into
181 * @max: maximum size of @events
182 *
183 * Returns: The number of events written.
184 * -ENOBUFS if there isn't enough space in the array to fit the
185 * encoding. In this case all @max events will have been written.
186 */
187static int ir_sony_encode(enum rc_proto protocol, u32 scancode,
188 struct ir_raw_event *events, unsigned int max)
189{
190 struct ir_raw_event *e = events;
191 u32 raw, len;
192 int ret;
193
194 if (protocol == RC_PROTO_SONY12) {
195 raw = (scancode & 0x7f) | ((scancode & 0x1f0000) >> 9);
196 len = 12;
197 } else if (protocol == RC_PROTO_SONY15) {
198 raw = (scancode & 0x7f) | ((scancode & 0xff0000) >> 9);
199 len = 15;
200 } else {
201 raw = (scancode & 0x7f) | ((scancode & 0x1f0000) >> 9) |
202 ((scancode & 0xff00) << 4);
203 len = 20;
204 }
205
206 ret = ir_raw_gen_pl(ev: &e, max, timings: &ir_sony_timings, n: len, data: raw);
207 if (ret < 0)
208 return ret;
209
210 return e - events;
211}
212
213static struct ir_raw_handler sony_handler = {
214 .protocols = RC_PROTO_BIT_SONY12 | RC_PROTO_BIT_SONY15 |
215 RC_PROTO_BIT_SONY20,
216 .decode = ir_sony_decode,
217 .encode = ir_sony_encode,
218 .carrier = 40000,
219 .min_timeout = SONY_TRAILER_SPACE,
220};
221
222static int __init ir_sony_decode_init(void)
223{
224 ir_raw_handler_register(ir_raw_handler: &sony_handler);
225
226 printk(KERN_INFO "IR Sony protocol handler initialized\n");
227 return 0;
228}
229
230static void __exit ir_sony_decode_exit(void)
231{
232 ir_raw_handler_unregister(ir_raw_handler: &sony_handler);
233}
234
235module_init(ir_sony_decode_init);
236module_exit(ir_sony_decode_exit);
237
238MODULE_LICENSE("GPL");
239MODULE_AUTHOR("David Härdeman <david@hardeman.nu>");
240MODULE_DESCRIPTION("Sony IR protocol decoder");
241

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