18e8e69d6SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only
21d184b0bSJames Hogan /* ir-sharp-decoder.c - handle Sharp IR Pulse/Space protocol
31d184b0bSJames Hogan *
41d184b0bSJames Hogan * Copyright (C) 2013-2014 Imagination Technologies Ltd.
51d184b0bSJames Hogan *
61d184b0bSJames Hogan * Based on NEC decoder:
737e59f87SMauro Carvalho Chehab * Copyright (C) 2010 by Mauro Carvalho Chehab
81d184b0bSJames Hogan */
91d184b0bSJames Hogan
101d184b0bSJames Hogan #include <linux/bitrev.h>
111d184b0bSJames Hogan #include <linux/module.h>
121d184b0bSJames Hogan #include "rc-core-priv.h"
131d184b0bSJames Hogan
141d184b0bSJames Hogan #define SHARP_NBITS 15
15528222d8SSean Young #define SHARP_UNIT 40 /* us */
161d184b0bSJames Hogan #define SHARP_BIT_PULSE (8 * SHARP_UNIT) /* 320us */
171d184b0bSJames Hogan #define SHARP_BIT_0_PERIOD (25 * SHARP_UNIT) /* 1ms (680us space) */
18*e981ecbaSSean Young #define SHARP_BIT_1_PERIOD (50 * SHARP_UNIT) /* 2ms (1680us space) */
19*e981ecbaSSean Young #define SHARP_BIT_0_SPACE (17 * SHARP_UNIT) /* 680us space */
20*e981ecbaSSean Young #define SHARP_BIT_1_SPACE (42 * SHARP_UNIT) /* 1680us space */
211d184b0bSJames Hogan #define SHARP_ECHO_SPACE (1000 * SHARP_UNIT) /* 40 ms */
221d184b0bSJames Hogan #define SHARP_TRAILER_SPACE (125 * SHARP_UNIT) /* 5 ms (even longer) */
231d184b0bSJames Hogan
241d184b0bSJames Hogan enum sharp_state {
251d184b0bSJames Hogan STATE_INACTIVE,
261d184b0bSJames Hogan STATE_BIT_PULSE,
271d184b0bSJames Hogan STATE_BIT_SPACE,
281d184b0bSJames Hogan STATE_TRAILER_PULSE,
291d184b0bSJames Hogan STATE_ECHO_SPACE,
301d184b0bSJames Hogan STATE_TRAILER_SPACE,
311d184b0bSJames Hogan };
321d184b0bSJames Hogan
331d184b0bSJames Hogan /**
341d184b0bSJames Hogan * ir_sharp_decode() - Decode one Sharp pulse or space
351d184b0bSJames Hogan * @dev: the struct rc_dev descriptor of the device
361855e988SMauro Carvalho Chehab * @ev: the struct ir_raw_event descriptor of the pulse/space
371d184b0bSJames Hogan *
381d184b0bSJames Hogan * This function returns -EINVAL if the pulse violates the state machine
391d184b0bSJames Hogan */
ir_sharp_decode(struct rc_dev * dev,struct ir_raw_event ev)401d184b0bSJames Hogan static int ir_sharp_decode(struct rc_dev *dev, struct ir_raw_event ev)
411d184b0bSJames Hogan {
421d184b0bSJames Hogan struct sharp_dec *data = &dev->raw->sharp;
431d184b0bSJames Hogan u32 msg, echo, address, command, scancode;
441d184b0bSJames Hogan
451d184b0bSJames Hogan if (!is_timing_event(ev)) {
46950170d6SSean Young if (ev.overflow)
471d184b0bSJames Hogan data->state = STATE_INACTIVE;
481d184b0bSJames Hogan return 0;
491d184b0bSJames Hogan }
501d184b0bSJames Hogan
5150078a90SSean Young dev_dbg(&dev->dev, "Sharp decode started at state %d (%uus %s)\n",
52528222d8SSean Young data->state, ev.duration, TO_STR(ev.pulse));
531d184b0bSJames Hogan
541d184b0bSJames Hogan switch (data->state) {
551d184b0bSJames Hogan
561d184b0bSJames Hogan case STATE_INACTIVE:
571d184b0bSJames Hogan if (!ev.pulse)
581d184b0bSJames Hogan break;
591d184b0bSJames Hogan
601d184b0bSJames Hogan if (!eq_margin(ev.duration, SHARP_BIT_PULSE,
611d184b0bSJames Hogan SHARP_BIT_PULSE / 2))
621d184b0bSJames Hogan break;
631d184b0bSJames Hogan
641d184b0bSJames Hogan data->count = 0;
651d184b0bSJames Hogan data->pulse_len = ev.duration;
661d184b0bSJames Hogan data->state = STATE_BIT_SPACE;
671d184b0bSJames Hogan return 0;
681d184b0bSJames Hogan
691d184b0bSJames Hogan case STATE_BIT_PULSE:
701d184b0bSJames Hogan if (!ev.pulse)
711d184b0bSJames Hogan break;
721d184b0bSJames Hogan
731d184b0bSJames Hogan if (!eq_margin(ev.duration, SHARP_BIT_PULSE,
741d184b0bSJames Hogan SHARP_BIT_PULSE / 2))
751d184b0bSJames Hogan break;
761d184b0bSJames Hogan
771d184b0bSJames Hogan data->pulse_len = ev.duration;
781d184b0bSJames Hogan data->state = STATE_BIT_SPACE;
791d184b0bSJames Hogan return 0;
801d184b0bSJames Hogan
811d184b0bSJames Hogan case STATE_BIT_SPACE:
821d184b0bSJames Hogan if (ev.pulse)
831d184b0bSJames Hogan break;
841d184b0bSJames Hogan
851d184b0bSJames Hogan data->bits <<= 1;
861d184b0bSJames Hogan if (eq_margin(data->pulse_len + ev.duration, SHARP_BIT_1_PERIOD,
871d184b0bSJames Hogan SHARP_BIT_PULSE * 2))
881d184b0bSJames Hogan data->bits |= 1;
891d184b0bSJames Hogan else if (!eq_margin(data->pulse_len + ev.duration,
901d184b0bSJames Hogan SHARP_BIT_0_PERIOD, SHARP_BIT_PULSE * 2))
911d184b0bSJames Hogan break;
921d184b0bSJames Hogan data->count++;
931d184b0bSJames Hogan
941d184b0bSJames Hogan if (data->count == SHARP_NBITS ||
951d184b0bSJames Hogan data->count == SHARP_NBITS * 2)
961d184b0bSJames Hogan data->state = STATE_TRAILER_PULSE;
971d184b0bSJames Hogan else
981d184b0bSJames Hogan data->state = STATE_BIT_PULSE;
991d184b0bSJames Hogan
1001d184b0bSJames Hogan return 0;
1011d184b0bSJames Hogan
1021d184b0bSJames Hogan case STATE_TRAILER_PULSE:
1031d184b0bSJames Hogan if (!ev.pulse)
1041d184b0bSJames Hogan break;
1051d184b0bSJames Hogan
1061d184b0bSJames Hogan if (!eq_margin(ev.duration, SHARP_BIT_PULSE,
1071d184b0bSJames Hogan SHARP_BIT_PULSE / 2))
1081d184b0bSJames Hogan break;
1091d184b0bSJames Hogan
1101d184b0bSJames Hogan if (data->count == SHARP_NBITS) {
1111d184b0bSJames Hogan /* exp,chk bits should be 1,0 */
1121b0621afSHeiner Kallweit if ((data->bits & 0x3) != 0x2 &&
1131b0621afSHeiner Kallweit /* DENON variant, both chk bits 0 */
1141b0621afSHeiner Kallweit (data->bits & 0x3) != 0x0)
1151d184b0bSJames Hogan break;
1161d184b0bSJames Hogan data->state = STATE_ECHO_SPACE;
1171d184b0bSJames Hogan } else {
1181d184b0bSJames Hogan data->state = STATE_TRAILER_SPACE;
1191d184b0bSJames Hogan }
1201d184b0bSJames Hogan return 0;
1211d184b0bSJames Hogan
1221d184b0bSJames Hogan case STATE_ECHO_SPACE:
1231d184b0bSJames Hogan if (ev.pulse)
1241d184b0bSJames Hogan break;
1251d184b0bSJames Hogan
1261d184b0bSJames Hogan if (!eq_margin(ev.duration, SHARP_ECHO_SPACE,
1271d184b0bSJames Hogan SHARP_ECHO_SPACE / 4))
1281d184b0bSJames Hogan break;
1291d184b0bSJames Hogan
1301d184b0bSJames Hogan data->state = STATE_BIT_PULSE;
1311d184b0bSJames Hogan
1321d184b0bSJames Hogan return 0;
1331d184b0bSJames Hogan
1341d184b0bSJames Hogan case STATE_TRAILER_SPACE:
1351d184b0bSJames Hogan if (ev.pulse)
1361d184b0bSJames Hogan break;
1371d184b0bSJames Hogan
1381d184b0bSJames Hogan if (!geq_margin(ev.duration, SHARP_TRAILER_SPACE,
1391d184b0bSJames Hogan SHARP_BIT_PULSE / 2))
1401d184b0bSJames Hogan break;
1411d184b0bSJames Hogan
1421d184b0bSJames Hogan /* Validate - command, ext, chk should be inverted in 2nd */
1431d184b0bSJames Hogan msg = (data->bits >> 15) & 0x7fff;
1441d184b0bSJames Hogan echo = data->bits & 0x7fff;
1451d184b0bSJames Hogan if ((msg ^ echo) != 0x3ff) {
14650078a90SSean Young dev_dbg(&dev->dev,
1471d184b0bSJames Hogan "Sharp checksum error: received 0x%04x, 0x%04x\n",
1481d184b0bSJames Hogan msg, echo);
1491d184b0bSJames Hogan break;
1501d184b0bSJames Hogan }
1511d184b0bSJames Hogan
1521d184b0bSJames Hogan address = bitrev8((msg >> 7) & 0xf8);
1531d184b0bSJames Hogan command = bitrev8((msg >> 2) & 0xff);
1541d184b0bSJames Hogan
1551d184b0bSJames Hogan scancode = address << 8 | command;
15650078a90SSean Young dev_dbg(&dev->dev, "Sharp scancode 0x%04x\n", scancode);
1571d184b0bSJames Hogan
1586d741bfeSSean Young rc_keydown(dev, RC_PROTO_SHARP, scancode, 0);
1591d184b0bSJames Hogan data->state = STATE_INACTIVE;
1601d184b0bSJames Hogan return 0;
1611d184b0bSJames Hogan }
1621d184b0bSJames Hogan
16350078a90SSean Young dev_dbg(&dev->dev, "Sharp decode failed at count %d state %d (%uus %s)\n",
164528222d8SSean Young data->count, data->state, ev.duration, TO_STR(ev.pulse));
1651d184b0bSJames Hogan data->state = STATE_INACTIVE;
1661d184b0bSJames Hogan return -EINVAL;
1671d184b0bSJames Hogan }
1681d184b0bSJames Hogan
169d35afc5fSSean Young static const struct ir_raw_timings_pd ir_sharp_timings = {
170d35afc5fSSean Young .header_pulse = 0,
171d35afc5fSSean Young .header_space = 0,
172d35afc5fSSean Young .bit_pulse = SHARP_BIT_PULSE,
173*e981ecbaSSean Young .bit_space[0] = SHARP_BIT_0_SPACE,
174*e981ecbaSSean Young .bit_space[1] = SHARP_BIT_1_SPACE,
175d35afc5fSSean Young .trailer_pulse = SHARP_BIT_PULSE,
176d35afc5fSSean Young .trailer_space = SHARP_ECHO_SPACE,
177d35afc5fSSean Young .msb_first = 1,
178d35afc5fSSean Young };
179d35afc5fSSean Young
180d35afc5fSSean Young /**
181d35afc5fSSean Young * ir_sharp_encode() - Encode a scancode as a stream of raw events
182d35afc5fSSean Young *
183d35afc5fSSean Young * @protocol: protocol to encode
184d35afc5fSSean Young * @scancode: scancode to encode
185d35afc5fSSean Young * @events: array of raw ir events to write into
186d35afc5fSSean Young * @max: maximum size of @events
187d35afc5fSSean Young *
188d35afc5fSSean Young * Returns: The number of events written.
189d35afc5fSSean Young * -ENOBUFS if there isn't enough space in the array to fit the
190d35afc5fSSean Young * encoding. In this case all @max events will have been written.
191d35afc5fSSean Young */
ir_sharp_encode(enum rc_proto protocol,u32 scancode,struct ir_raw_event * events,unsigned int max)1926d741bfeSSean Young static int ir_sharp_encode(enum rc_proto protocol, u32 scancode,
193d35afc5fSSean Young struct ir_raw_event *events, unsigned int max)
194d35afc5fSSean Young {
195d35afc5fSSean Young struct ir_raw_event *e = events;
196d35afc5fSSean Young int ret;
197d35afc5fSSean Young u32 raw;
198d35afc5fSSean Young
199d35afc5fSSean Young raw = (((bitrev8(scancode >> 8) >> 3) << 8) & 0x1f00) |
200d35afc5fSSean Young bitrev8(scancode);
201d35afc5fSSean Young ret = ir_raw_gen_pd(&e, max, &ir_sharp_timings, SHARP_NBITS,
202d35afc5fSSean Young (raw << 2) | 2);
203d35afc5fSSean Young if (ret < 0)
204d35afc5fSSean Young return ret;
205d35afc5fSSean Young
206d35afc5fSSean Young max -= ret;
207d35afc5fSSean Young
208d35afc5fSSean Young raw = (((bitrev8(scancode >> 8) >> 3) << 8) & 0x1f00) |
209d35afc5fSSean Young bitrev8(~scancode);
210d35afc5fSSean Young ret = ir_raw_gen_pd(&e, max, &ir_sharp_timings, SHARP_NBITS,
211d35afc5fSSean Young (raw << 2) | 1);
212d35afc5fSSean Young if (ret < 0)
213d35afc5fSSean Young return ret;
214d35afc5fSSean Young
215d35afc5fSSean Young return e - events;
216d35afc5fSSean Young }
217d35afc5fSSean Young
2181d184b0bSJames Hogan static struct ir_raw_handler sharp_handler = {
2196d741bfeSSean Young .protocols = RC_PROTO_BIT_SHARP,
2201d184b0bSJames Hogan .decode = ir_sharp_decode,
221d35afc5fSSean Young .encode = ir_sharp_encode,
222cdfaa01cSSean Young .carrier = 38000,
223a86d6df8SSean Young .min_timeout = SHARP_ECHO_SPACE + SHARP_ECHO_SPACE / 4,
2241d184b0bSJames Hogan };
2251d184b0bSJames Hogan
ir_sharp_decode_init(void)2261d184b0bSJames Hogan static int __init ir_sharp_decode_init(void)
2271d184b0bSJames Hogan {
2281d184b0bSJames Hogan ir_raw_handler_register(&sharp_handler);
2291d184b0bSJames Hogan
2301d184b0bSJames Hogan pr_info("IR Sharp protocol handler initialized\n");
2311d184b0bSJames Hogan return 0;
2321d184b0bSJames Hogan }
2331d184b0bSJames Hogan
ir_sharp_decode_exit(void)2341d184b0bSJames Hogan static void __exit ir_sharp_decode_exit(void)
2351d184b0bSJames Hogan {
2361d184b0bSJames Hogan ir_raw_handler_unregister(&sharp_handler);
2371d184b0bSJames Hogan }
2381d184b0bSJames Hogan
2391d184b0bSJames Hogan module_init(ir_sharp_decode_init);
2401d184b0bSJames Hogan module_exit(ir_sharp_decode_exit);
2411d184b0bSJames Hogan
2421d184b0bSJames Hogan MODULE_LICENSE("GPL");
243e0a86312SJames Hogan MODULE_AUTHOR("James Hogan <jhogan@kernel.org>");
2441d184b0bSJames Hogan MODULE_DESCRIPTION("Sharp IR protocol decoder");
245