1733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman/* ir-rc5-decoder.c - handle RC5(x) IR Pulse/Space protocol 2db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab * 3db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab * Copyright (C) 2010 by Mauro Carvalho Chehab <mchehab@redhat.com> 4db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab * 5db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab * This program is free software; you can redistribute it and/or modify 6db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab * it under the terms of the GNU General Public License as published by 7db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab * the Free Software Foundation version 2 of the License. 8db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab * 9db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab * This program is distributed in the hope that it will be useful, 10db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab * but WITHOUT ANY WARRANTY; without even the implied warranty of 11db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab * GNU General Public License for more details. 13db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab */ 14db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 15db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab/* 16733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman * This code handles 14 bits RC5 protocols and 20 bits RC5x protocols. 17733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman * There are other variants that use a different number of bits. 18733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman * This is currently unsupported. 19733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman * It considers a carrier of 36 kHz, with a total of 14/20 bits, where 209b09df51b8c2b4615376e5ada3e2eb7eeed3cf5dMauro Carvalho Chehab * the first two bits are start bits, and a third one is a filing bit 21db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab */ 22db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 23f62de675f796a992011c598c405a3d6fada9aa20Mauro Carvalho Chehab#include "rc-core-priv.h" 247a707b89202f905bd9f9fbde326933c59a81214cPaul Gortmaker#include <linux/module.h> 25db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 269b09df51b8c2b4615376e5ada3e2eb7eeed3cf5dMauro Carvalho Chehab#define RC5_NBITS 14 27733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman#define RC5X_NBITS 20 28733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman#define CHECK_RC5X_NBITS 8 29724e2495502a98aaa3f93c404472a991da8ff857David Härdeman#define RC5_UNIT 888888 /* ns */ 30e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman#define RC5_BIT_START (1 * RC5_UNIT) 31e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman#define RC5_BIT_END (1 * RC5_UNIT) 32e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman#define RC5X_SPACE (4 * RC5_UNIT) 33db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 34db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehabenum rc5_state { 35db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab STATE_INACTIVE, 36724e2495502a98aaa3f93c404472a991da8ff857David Härdeman STATE_BIT_START, 37724e2495502a98aaa3f93c404472a991da8ff857David Härdeman STATE_BIT_END, 38733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman STATE_CHECK_RC5X, 39724e2495502a98aaa3f93c404472a991da8ff857David Härdeman STATE_FINISHED, 40db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab}; 41db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 42db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab/** 43724e2495502a98aaa3f93c404472a991da8ff857David Härdeman * ir_rc5_decode() - Decode one RC-5 pulse or space 44d8b4b5822f51e2142b731b42c81e3f03eec475b2David Härdeman * @dev: the struct rc_dev descriptor of the device 45e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman * @ev: the struct ir_raw_event descriptor of the pulse/space 46db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab * 47db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab * This function returns -EINVAL if the pulse violates the state machine 48db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab */ 49d8b4b5822f51e2142b731b42c81e3f03eec475b2David Härdemanstatic int ir_rc5_decode(struct rc_dev *dev, struct ir_raw_event ev) 50db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab{ 51d8b4b5822f51e2142b731b42c81e3f03eec475b2David Härdeman struct rc5_dec *data = &dev->raw->rc5; 52733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman u8 toggle; 53724e2495502a98aaa3f93c404472a991da8ff857David Härdeman u32 scancode; 54db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 5552b661449aecc47e652a164c0d8078b31e10aca0Mauro Carvalho Chehab if (!(dev->raw->enabled_protocols & RC_TYPE_RC5)) 56667c9ebe97f7e5f1e48e7eb321644c6fb1668de5David Härdeman return 0; 577f20d32d446097789ade5ada6b645742ddac4eceMauro Carvalho Chehab 584651918a4afdd49bdea21d2f919b189ef17a6399Maxim Levitsky if (!is_timing_event(ev)) { 594651918a4afdd49bdea21d2f919b189ef17a6399Maxim Levitsky if (ev.reset) 604651918a4afdd49bdea21d2f919b189ef17a6399Maxim Levitsky data->state = STATE_INACTIVE; 61db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab return 0; 62724e2495502a98aaa3f93c404472a991da8ff857David Härdeman } 63db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 64e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman if (!geq_margin(ev.duration, RC5_UNIT, RC5_UNIT / 2)) 65724e2495502a98aaa3f93c404472a991da8ff857David Härdeman goto out; 66db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 67724e2495502a98aaa3f93c404472a991da8ff857David Härdemanagain: 68e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman IR_dprintk(2, "RC5(x) decode started at state %i (%uus %s)\n", 69e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman data->state, TO_US(ev.duration), TO_STR(ev.pulse)); 70db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 71e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman if (!geq_margin(ev.duration, RC5_UNIT, RC5_UNIT / 2)) 72724e2495502a98aaa3f93c404472a991da8ff857David Härdeman return 0; 73db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 74724e2495502a98aaa3f93c404472a991da8ff857David Härdeman switch (data->state) { 75db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 76724e2495502a98aaa3f93c404472a991da8ff857David Härdeman case STATE_INACTIVE: 77e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman if (!ev.pulse) 78e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman break; 79e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman 80e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman data->state = STATE_BIT_START; 81e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman data->count = 1; 82e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman /* We just need enough bits to get to STATE_CHECK_RC5X */ 83e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman data->wanted_bits = RC5X_NBITS; 84e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman decrease_duration(&ev, RC5_BIT_START); 85e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman goto again; 86724e2495502a98aaa3f93c404472a991da8ff857David Härdeman 87724e2495502a98aaa3f93c404472a991da8ff857David Härdeman case STATE_BIT_START: 88e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman if (!eq_margin(ev.duration, RC5_BIT_START, RC5_UNIT / 2)) 89e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman break; 90e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman 91c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman data->bits <<= 1; 92e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman if (!ev.pulse) 93c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman data->bits |= 1; 94e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman data->count++; 95e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman data->state = STATE_BIT_END; 96e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman return 0; 979b09df51b8c2b4615376e5ada3e2eb7eeed3cf5dMauro Carvalho Chehab 98724e2495502a98aaa3f93c404472a991da8ff857David Härdeman case STATE_BIT_END: 99d8b4b5822f51e2142b731b42c81e3f03eec475b2David Härdeman if (!is_transition(&ev, &dev->raw->prev_ev)) 100e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman break; 101e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman 102e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman if (data->count == data->wanted_bits) 103e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman data->state = STATE_FINISHED; 104e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman else if (data->count == CHECK_RC5X_NBITS) 105e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman data->state = STATE_CHECK_RC5X; 106e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman else 107e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman data->state = STATE_BIT_START; 108e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman 109e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman decrease_duration(&ev, RC5_BIT_END); 110e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman goto again; 111724e2495502a98aaa3f93c404472a991da8ff857David Härdeman 112733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman case STATE_CHECK_RC5X: 113e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman if (!ev.pulse && geq_margin(ev.duration, RC5X_SPACE, RC5_UNIT / 2)) { 114733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman /* RC5X */ 115733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman data->wanted_bits = RC5X_NBITS; 116e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman decrease_duration(&ev, RC5X_SPACE); 117733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman } else { 118733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman /* RC5 */ 119733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman data->wanted_bits = RC5_NBITS; 120733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman } 121733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman data->state = STATE_BIT_START; 122733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman goto again; 123733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman 124724e2495502a98aaa3f93c404472a991da8ff857David Härdeman case STATE_FINISHED: 125e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman if (ev.pulse) 126e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman break; 127e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman 128733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman if (data->wanted_bits == RC5X_NBITS) { 129733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman /* RC5X */ 130733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman u8 xdata, command, system; 131c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman xdata = (data->bits & 0x0003F) >> 0; 132c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman command = (data->bits & 0x00FC0) >> 6; 133c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman system = (data->bits & 0x1F000) >> 12; 134c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman toggle = (data->bits & 0x20000) ? 1 : 0; 135c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman command += (data->bits & 0x01000) ? 0 : 0x40; 136733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman scancode = system << 16 | command << 8 | xdata; 137733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman 138733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman IR_dprintk(1, "RC5X scancode 0x%06x (toggle: %u)\n", 139733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman scancode, toggle); 140733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman 141733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman } else { 142733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman /* RC5 */ 143733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman u8 command, system; 144c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman command = (data->bits & 0x0003F) >> 0; 145c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman system = (data->bits & 0x007C0) >> 6; 146c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman toggle = (data->bits & 0x00800) ? 1 : 0; 147c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman command += (data->bits & 0x01000) ? 0 : 0x40; 148733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman scancode = system << 8 | command; 149733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman 150733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman IR_dprintk(1, "RC5 scancode 0x%04x (toggle: %u)\n", 151733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman scancode, toggle); 152733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman } 153733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman 154ca86674b8a93ea11c4bb6f4dd0113b1adf1fa841Mauro Carvalho Chehab rc_keydown(dev, scancode, toggle); 155db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab data->state = STATE_INACTIVE; 156db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab return 0; 157db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab } 158db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 159724e2495502a98aaa3f93c404472a991da8ff857David Härdemanout: 160e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman IR_dprintk(1, "RC5(x) decode failed at state %i (%uus %s)\n", 161e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman data->state, TO_US(ev.duration), TO_STR(ev.pulse)); 162db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab data->state = STATE_INACTIVE; 163db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab return -EINVAL; 164db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab} 165db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 166db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehabstatic struct ir_raw_handler rc5_handler = { 16752b661449aecc47e652a164c0d8078b31e10aca0Mauro Carvalho Chehab .protocols = RC_TYPE_RC5, 168db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab .decode = ir_rc5_decode, 169db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab}; 170db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 171db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehabstatic int __init ir_rc5_decode_init(void) 172db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab{ 173db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab ir_raw_handler_register(&rc5_handler); 174db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 175733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman printk(KERN_INFO "IR RC5(x) protocol handler initialized\n"); 176db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab return 0; 177db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab} 178db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 179db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehabstatic void __exit ir_rc5_decode_exit(void) 180db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab{ 181db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab ir_raw_handler_unregister(&rc5_handler); 182db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab} 183db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 184db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehabmodule_init(ir_rc5_decode_init); 185db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehabmodule_exit(ir_rc5_decode_exit); 186db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 187db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho ChehabMODULE_LICENSE("GPL"); 188db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho ChehabMODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>"); 189db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho ChehabMODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)"); 190733419b5c4d29186006982a9a27227e214a39dbcDavid HärdemanMODULE_DESCRIPTION("RC5(x) IR protocol decoder"); 191