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) */ 181d184b0bSJames Hogan #define SHARP_BIT_1_PERIOD (50 * SHARP_UNIT) /* 2ms (1680ms space) */ 191d184b0bSJames Hogan #define SHARP_ECHO_SPACE (1000 * SHARP_UNIT) /* 40 ms */ 201d184b0bSJames Hogan #define SHARP_TRAILER_SPACE (125 * SHARP_UNIT) /* 5 ms (even longer) */ 211d184b0bSJames Hogan 221d184b0bSJames Hogan enum sharp_state { 231d184b0bSJames Hogan STATE_INACTIVE, 241d184b0bSJames Hogan STATE_BIT_PULSE, 251d184b0bSJames Hogan STATE_BIT_SPACE, 261d184b0bSJames Hogan STATE_TRAILER_PULSE, 271d184b0bSJames Hogan STATE_ECHO_SPACE, 281d184b0bSJames Hogan STATE_TRAILER_SPACE, 291d184b0bSJames Hogan }; 301d184b0bSJames Hogan 311d184b0bSJames Hogan /** 321d184b0bSJames Hogan * ir_sharp_decode() - Decode one Sharp pulse or space 331d184b0bSJames Hogan * @dev: the struct rc_dev descriptor of the device 341855e988SMauro Carvalho Chehab * @ev: the struct ir_raw_event descriptor of the pulse/space 351d184b0bSJames Hogan * 361d184b0bSJames Hogan * This function returns -EINVAL if the pulse violates the state machine 371d184b0bSJames Hogan */ 381d184b0bSJames Hogan static int ir_sharp_decode(struct rc_dev *dev, struct ir_raw_event ev) 391d184b0bSJames Hogan { 401d184b0bSJames Hogan struct sharp_dec *data = &dev->raw->sharp; 411d184b0bSJames Hogan u32 msg, echo, address, command, scancode; 421d184b0bSJames Hogan 431d184b0bSJames Hogan if (!is_timing_event(ev)) { 44*950170d6SSean Young if (ev.overflow) 451d184b0bSJames Hogan data->state = STATE_INACTIVE; 461d184b0bSJames Hogan return 0; 471d184b0bSJames Hogan } 481d184b0bSJames Hogan 4950078a90SSean Young dev_dbg(&dev->dev, "Sharp decode started at state %d (%uus %s)\n", 50528222d8SSean Young data->state, ev.duration, TO_STR(ev.pulse)); 511d184b0bSJames Hogan 521d184b0bSJames Hogan switch (data->state) { 531d184b0bSJames Hogan 541d184b0bSJames Hogan case STATE_INACTIVE: 551d184b0bSJames Hogan if (!ev.pulse) 561d184b0bSJames Hogan break; 571d184b0bSJames Hogan 581d184b0bSJames Hogan if (!eq_margin(ev.duration, SHARP_BIT_PULSE, 591d184b0bSJames Hogan SHARP_BIT_PULSE / 2)) 601d184b0bSJames Hogan break; 611d184b0bSJames Hogan 621d184b0bSJames Hogan data->count = 0; 631d184b0bSJames Hogan data->pulse_len = ev.duration; 641d184b0bSJames Hogan data->state = STATE_BIT_SPACE; 651d184b0bSJames Hogan return 0; 661d184b0bSJames Hogan 671d184b0bSJames Hogan case STATE_BIT_PULSE: 681d184b0bSJames Hogan if (!ev.pulse) 691d184b0bSJames Hogan break; 701d184b0bSJames Hogan 711d184b0bSJames Hogan if (!eq_margin(ev.duration, SHARP_BIT_PULSE, 721d184b0bSJames Hogan SHARP_BIT_PULSE / 2)) 731d184b0bSJames Hogan break; 741d184b0bSJames Hogan 751d184b0bSJames Hogan data->pulse_len = ev.duration; 761d184b0bSJames Hogan data->state = STATE_BIT_SPACE; 771d184b0bSJames Hogan return 0; 781d184b0bSJames Hogan 791d184b0bSJames Hogan case STATE_BIT_SPACE: 801d184b0bSJames Hogan if (ev.pulse) 811d184b0bSJames Hogan break; 821d184b0bSJames Hogan 831d184b0bSJames Hogan data->bits <<= 1; 841d184b0bSJames Hogan if (eq_margin(data->pulse_len + ev.duration, SHARP_BIT_1_PERIOD, 851d184b0bSJames Hogan SHARP_BIT_PULSE * 2)) 861d184b0bSJames Hogan data->bits |= 1; 871d184b0bSJames Hogan else if (!eq_margin(data->pulse_len + ev.duration, 881d184b0bSJames Hogan SHARP_BIT_0_PERIOD, SHARP_BIT_PULSE * 2)) 891d184b0bSJames Hogan break; 901d184b0bSJames Hogan data->count++; 911d184b0bSJames Hogan 921d184b0bSJames Hogan if (data->count == SHARP_NBITS || 931d184b0bSJames Hogan data->count == SHARP_NBITS * 2) 941d184b0bSJames Hogan data->state = STATE_TRAILER_PULSE; 951d184b0bSJames Hogan else 961d184b0bSJames Hogan data->state = STATE_BIT_PULSE; 971d184b0bSJames Hogan 981d184b0bSJames Hogan return 0; 991d184b0bSJames Hogan 1001d184b0bSJames Hogan case STATE_TRAILER_PULSE: 1011d184b0bSJames Hogan if (!ev.pulse) 1021d184b0bSJames Hogan break; 1031d184b0bSJames Hogan 1041d184b0bSJames Hogan if (!eq_margin(ev.duration, SHARP_BIT_PULSE, 1051d184b0bSJames Hogan SHARP_BIT_PULSE / 2)) 1061d184b0bSJames Hogan break; 1071d184b0bSJames Hogan 1081d184b0bSJames Hogan if (data->count == SHARP_NBITS) { 1091d184b0bSJames Hogan /* exp,chk bits should be 1,0 */ 1101b0621afSHeiner Kallweit if ((data->bits & 0x3) != 0x2 && 1111b0621afSHeiner Kallweit /* DENON variant, both chk bits 0 */ 1121b0621afSHeiner Kallweit (data->bits & 0x3) != 0x0) 1131d184b0bSJames Hogan break; 1141d184b0bSJames Hogan data->state = STATE_ECHO_SPACE; 1151d184b0bSJames Hogan } else { 1161d184b0bSJames Hogan data->state = STATE_TRAILER_SPACE; 1171d184b0bSJames Hogan } 1181d184b0bSJames Hogan return 0; 1191d184b0bSJames Hogan 1201d184b0bSJames Hogan case STATE_ECHO_SPACE: 1211d184b0bSJames Hogan if (ev.pulse) 1221d184b0bSJames Hogan break; 1231d184b0bSJames Hogan 1241d184b0bSJames Hogan if (!eq_margin(ev.duration, SHARP_ECHO_SPACE, 1251d184b0bSJames Hogan SHARP_ECHO_SPACE / 4)) 1261d184b0bSJames Hogan break; 1271d184b0bSJames Hogan 1281d184b0bSJames Hogan data->state = STATE_BIT_PULSE; 1291d184b0bSJames Hogan 1301d184b0bSJames Hogan return 0; 1311d184b0bSJames Hogan 1321d184b0bSJames Hogan case STATE_TRAILER_SPACE: 1331d184b0bSJames Hogan if (ev.pulse) 1341d184b0bSJames Hogan break; 1351d184b0bSJames Hogan 1361d184b0bSJames Hogan if (!geq_margin(ev.duration, SHARP_TRAILER_SPACE, 1371d184b0bSJames Hogan SHARP_BIT_PULSE / 2)) 1381d184b0bSJames Hogan break; 1391d184b0bSJames Hogan 1401d184b0bSJames Hogan /* Validate - command, ext, chk should be inverted in 2nd */ 1411d184b0bSJames Hogan msg = (data->bits >> 15) & 0x7fff; 1421d184b0bSJames Hogan echo = data->bits & 0x7fff; 1431d184b0bSJames Hogan if ((msg ^ echo) != 0x3ff) { 14450078a90SSean Young dev_dbg(&dev->dev, 1451d184b0bSJames Hogan "Sharp checksum error: received 0x%04x, 0x%04x\n", 1461d184b0bSJames Hogan msg, echo); 1471d184b0bSJames Hogan break; 1481d184b0bSJames Hogan } 1491d184b0bSJames Hogan 1501d184b0bSJames Hogan address = bitrev8((msg >> 7) & 0xf8); 1511d184b0bSJames Hogan command = bitrev8((msg >> 2) & 0xff); 1521d184b0bSJames Hogan 1531d184b0bSJames Hogan scancode = address << 8 | command; 15450078a90SSean Young dev_dbg(&dev->dev, "Sharp scancode 0x%04x\n", scancode); 1551d184b0bSJames Hogan 1566d741bfeSSean Young rc_keydown(dev, RC_PROTO_SHARP, scancode, 0); 1571d184b0bSJames Hogan data->state = STATE_INACTIVE; 1581d184b0bSJames Hogan return 0; 1591d184b0bSJames Hogan } 1601d184b0bSJames Hogan 16150078a90SSean Young dev_dbg(&dev->dev, "Sharp decode failed at count %d state %d (%uus %s)\n", 162528222d8SSean Young data->count, data->state, ev.duration, TO_STR(ev.pulse)); 1631d184b0bSJames Hogan data->state = STATE_INACTIVE; 1641d184b0bSJames Hogan return -EINVAL; 1651d184b0bSJames Hogan } 1661d184b0bSJames Hogan 167d35afc5fSSean Young static const struct ir_raw_timings_pd ir_sharp_timings = { 168d35afc5fSSean Young .header_pulse = 0, 169d35afc5fSSean Young .header_space = 0, 170d35afc5fSSean Young .bit_pulse = SHARP_BIT_PULSE, 171d35afc5fSSean Young .bit_space[0] = SHARP_BIT_0_PERIOD, 172d35afc5fSSean Young .bit_space[1] = SHARP_BIT_1_PERIOD, 173d35afc5fSSean Young .trailer_pulse = SHARP_BIT_PULSE, 174d35afc5fSSean Young .trailer_space = SHARP_ECHO_SPACE, 175d35afc5fSSean Young .msb_first = 1, 176d35afc5fSSean Young }; 177d35afc5fSSean Young 178d35afc5fSSean Young /** 179d35afc5fSSean Young * ir_sharp_encode() - Encode a scancode as a stream of raw events 180d35afc5fSSean Young * 181d35afc5fSSean Young * @protocol: protocol to encode 182d35afc5fSSean Young * @scancode: scancode to encode 183d35afc5fSSean Young * @events: array of raw ir events to write into 184d35afc5fSSean Young * @max: maximum size of @events 185d35afc5fSSean Young * 186d35afc5fSSean Young * Returns: The number of events written. 187d35afc5fSSean Young * -ENOBUFS if there isn't enough space in the array to fit the 188d35afc5fSSean Young * encoding. In this case all @max events will have been written. 189d35afc5fSSean Young */ 1906d741bfeSSean Young static int ir_sharp_encode(enum rc_proto protocol, u32 scancode, 191d35afc5fSSean Young struct ir_raw_event *events, unsigned int max) 192d35afc5fSSean Young { 193d35afc5fSSean Young struct ir_raw_event *e = events; 194d35afc5fSSean Young int ret; 195d35afc5fSSean Young u32 raw; 196d35afc5fSSean Young 197d35afc5fSSean Young raw = (((bitrev8(scancode >> 8) >> 3) << 8) & 0x1f00) | 198d35afc5fSSean Young bitrev8(scancode); 199d35afc5fSSean Young ret = ir_raw_gen_pd(&e, max, &ir_sharp_timings, SHARP_NBITS, 200d35afc5fSSean Young (raw << 2) | 2); 201d35afc5fSSean Young if (ret < 0) 202d35afc5fSSean Young return ret; 203d35afc5fSSean Young 204d35afc5fSSean Young max -= ret; 205d35afc5fSSean Young 206d35afc5fSSean Young raw = (((bitrev8(scancode >> 8) >> 3) << 8) & 0x1f00) | 207d35afc5fSSean Young bitrev8(~scancode); 208d35afc5fSSean Young ret = ir_raw_gen_pd(&e, max, &ir_sharp_timings, SHARP_NBITS, 209d35afc5fSSean Young (raw << 2) | 1); 210d35afc5fSSean Young if (ret < 0) 211d35afc5fSSean Young return ret; 212d35afc5fSSean Young 213d35afc5fSSean Young return e - events; 214d35afc5fSSean Young } 215d35afc5fSSean Young 2161d184b0bSJames Hogan static struct ir_raw_handler sharp_handler = { 2176d741bfeSSean Young .protocols = RC_PROTO_BIT_SHARP, 2181d184b0bSJames Hogan .decode = ir_sharp_decode, 219d35afc5fSSean Young .encode = ir_sharp_encode, 220cdfaa01cSSean Young .carrier = 38000, 221a86d6df8SSean Young .min_timeout = SHARP_ECHO_SPACE + SHARP_ECHO_SPACE / 4, 2221d184b0bSJames Hogan }; 2231d184b0bSJames Hogan 2241d184b0bSJames Hogan static int __init ir_sharp_decode_init(void) 2251d184b0bSJames Hogan { 2261d184b0bSJames Hogan ir_raw_handler_register(&sharp_handler); 2271d184b0bSJames Hogan 2281d184b0bSJames Hogan pr_info("IR Sharp protocol handler initialized\n"); 2291d184b0bSJames Hogan return 0; 2301d184b0bSJames Hogan } 2311d184b0bSJames Hogan 2321d184b0bSJames Hogan static void __exit ir_sharp_decode_exit(void) 2331d184b0bSJames Hogan { 2341d184b0bSJames Hogan ir_raw_handler_unregister(&sharp_handler); 2351d184b0bSJames Hogan } 2361d184b0bSJames Hogan 2371d184b0bSJames Hogan module_init(ir_sharp_decode_init); 2381d184b0bSJames Hogan module_exit(ir_sharp_decode_exit); 2391d184b0bSJames Hogan 2401d184b0bSJames Hogan MODULE_LICENSE("GPL"); 241e0a86312SJames Hogan MODULE_AUTHOR("James Hogan <jhogan@kernel.org>"); 2421d184b0bSJames Hogan MODULE_DESCRIPTION("Sharp IR protocol decoder"); 243