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 H��rdeman <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(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(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(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(ev.duration, SONY_BIT_1_PULSE, SONY_UNIT / 2))
82			data->bits |= 1;
83		else if (!eq_margin(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(ev.duration, SONY_BIT_SPACE, SONY_UNIT / 2))
95			break;
96
97		decrease_duration(&ev, SONY_BIT_SPACE);
98
99		if (!geq_margin(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(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, 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(&e, max, &ir_sony_timings, len, 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(&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(&sony_handler);
233}
234
235module_init(ir_sony_decode_init);
236module_exit(ir_sony_decode_exit);
237
238MODULE_LICENSE("GPL");
239MODULE_AUTHOR("David H��rdeman <david@hardeman.nu>");
240MODULE_DESCRIPTION("Sony IR protocol decoder");
241