ir-rc5-decoder.c revision c216369e61fae586cd48c0913cca2a37fbfeb912
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 233f113e36106f133752de47208816b28aa8e60f88Mauro Carvalho Chehab#include "ir-core-priv.h" 24db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 259b09df51b8c2b4615376e5ada3e2eb7eeed3cf5dMauro Carvalho Chehab#define RC5_NBITS 14 26733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman#define RC5X_NBITS 20 27733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman#define CHECK_RC5X_NBITS 8 28724e2495502a98aaa3f93c404472a991da8ff857David Härdeman#define RC5_UNIT 888888 /* ns */ 29e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman#define RC5_BIT_START (1 * RC5_UNIT) 30e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman#define RC5_BIT_END (1 * RC5_UNIT) 31e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman#define RC5X_SPACE (4 * RC5_UNIT) 32db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 33db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehabenum rc5_state { 34db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab STATE_INACTIVE, 35724e2495502a98aaa3f93c404472a991da8ff857David Härdeman STATE_BIT_START, 36724e2495502a98aaa3f93c404472a991da8ff857David Härdeman STATE_BIT_END, 37733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman STATE_CHECK_RC5X, 38724e2495502a98aaa3f93c404472a991da8ff857David Härdeman STATE_FINISHED, 39db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab}; 40db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 41db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab/** 42724e2495502a98aaa3f93c404472a991da8ff857David Härdeman * ir_rc5_decode() - Decode one RC-5 pulse or space 43db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab * @input_dev: the struct input_dev descriptor of the device 44e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman * @ev: the struct ir_raw_event descriptor of the pulse/space 45db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab * 46db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab * This function returns -EINVAL if the pulse violates the state machine 47db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab */ 48e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdemanstatic int ir_rc5_decode(struct input_dev *input_dev, struct ir_raw_event ev) 49db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab{ 50db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab struct ir_input_dev *ir_dev = input_get_drvdata(input_dev); 51c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman struct rc5_dec *data = &ir_dev->raw->rc5; 52733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman u8 toggle; 53724e2495502a98aaa3f93c404472a991da8ff857David Härdeman u32 scancode; 54db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 55667c9ebe97f7e5f1e48e7eb321644c6fb1668de5David Härdeman if (!(ir_dev->raw->enabled_protocols & IR_TYPE_RC5)) 56667c9ebe97f7e5f1e48e7eb321644c6fb1668de5David Härdeman return 0; 577f20d32d446097789ade5ada6b645742ddac4eceMauro Carvalho Chehab 58e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman if (IS_RESET(ev)) { 59db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab data->state = STATE_INACTIVE; 60db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab return 0; 61724e2495502a98aaa3f93c404472a991da8ff857David Härdeman } 62db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 63e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman if (!geq_margin(ev.duration, RC5_UNIT, RC5_UNIT / 2)) 64724e2495502a98aaa3f93c404472a991da8ff857David Härdeman goto out; 65db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 66724e2495502a98aaa3f93c404472a991da8ff857David Härdemanagain: 67e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman IR_dprintk(2, "RC5(x) decode started at state %i (%uus %s)\n", 68e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman data->state, TO_US(ev.duration), TO_STR(ev.pulse)); 69db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 70e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman if (!geq_margin(ev.duration, RC5_UNIT, RC5_UNIT / 2)) 71724e2495502a98aaa3f93c404472a991da8ff857David Härdeman return 0; 72db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 73724e2495502a98aaa3f93c404472a991da8ff857David Härdeman switch (data->state) { 74db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 75724e2495502a98aaa3f93c404472a991da8ff857David Härdeman case STATE_INACTIVE: 76e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman if (!ev.pulse) 77e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman break; 78e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman 79e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman data->state = STATE_BIT_START; 80e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman data->count = 1; 81e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman /* We just need enough bits to get to STATE_CHECK_RC5X */ 82e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman data->wanted_bits = RC5X_NBITS; 83e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman decrease_duration(&ev, RC5_BIT_START); 84e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman goto again; 85724e2495502a98aaa3f93c404472a991da8ff857David Härdeman 86724e2495502a98aaa3f93c404472a991da8ff857David Härdeman case STATE_BIT_START: 87e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman if (!eq_margin(ev.duration, RC5_BIT_START, RC5_UNIT / 2)) 88e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman break; 89e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman 90c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman data->bits <<= 1; 91e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman if (!ev.pulse) 92c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman data->bits |= 1; 93e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman data->count++; 94e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman data->state = STATE_BIT_END; 95e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman return 0; 969b09df51b8c2b4615376e5ada3e2eb7eeed3cf5dMauro Carvalho Chehab 97724e2495502a98aaa3f93c404472a991da8ff857David Härdeman case STATE_BIT_END: 98c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman if (!is_transition(&ev, &ir_dev->raw->prev_ev)) 99e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman break; 100e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman 101e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman if (data->count == data->wanted_bits) 102e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman data->state = STATE_FINISHED; 103e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman else if (data->count == CHECK_RC5X_NBITS) 104e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman data->state = STATE_CHECK_RC5X; 105e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman else 106e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman data->state = STATE_BIT_START; 107e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman 108e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman decrease_duration(&ev, RC5_BIT_END); 109e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman goto again; 110724e2495502a98aaa3f93c404472a991da8ff857David Härdeman 111733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman case STATE_CHECK_RC5X: 112e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman if (!ev.pulse && geq_margin(ev.duration, RC5X_SPACE, RC5_UNIT / 2)) { 113733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman /* RC5X */ 114733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman data->wanted_bits = RC5X_NBITS; 115e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman decrease_duration(&ev, RC5X_SPACE); 116733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman } else { 117733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman /* RC5 */ 118733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman data->wanted_bits = RC5_NBITS; 119733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman } 120733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman data->state = STATE_BIT_START; 121733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman goto again; 122733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman 123724e2495502a98aaa3f93c404472a991da8ff857David Härdeman case STATE_FINISHED: 124e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman if (ev.pulse) 125e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman break; 126e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman 127733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman if (data->wanted_bits == RC5X_NBITS) { 128733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman /* RC5X */ 129733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman u8 xdata, command, system; 130c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman xdata = (data->bits & 0x0003F) >> 0; 131c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman command = (data->bits & 0x00FC0) >> 6; 132c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman system = (data->bits & 0x1F000) >> 12; 133c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman toggle = (data->bits & 0x20000) ? 1 : 0; 134c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman command += (data->bits & 0x01000) ? 0 : 0x40; 135733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman scancode = system << 16 | command << 8 | xdata; 136733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman 137733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman IR_dprintk(1, "RC5X scancode 0x%06x (toggle: %u)\n", 138733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman scancode, toggle); 139733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman 140733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman } else { 141733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman /* RC5 */ 142733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman u8 command, system; 143c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman command = (data->bits & 0x0003F) >> 0; 144c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman system = (data->bits & 0x007C0) >> 6; 145c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman toggle = (data->bits & 0x00800) ? 1 : 0; 146c216369e61fae586cd48c0913cca2a37fbfeb912David Härdeman command += (data->bits & 0x01000) ? 0 : 0x40; 147733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman scancode = system << 8 | command; 148733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman 149733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman IR_dprintk(1, "RC5 scancode 0x%04x (toggle: %u)\n", 150733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman scancode, toggle); 151733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman } 152733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman 153724e2495502a98aaa3f93c404472a991da8ff857David Härdeman ir_keydown(input_dev, scancode, toggle); 154db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab data->state = STATE_INACTIVE; 155db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab return 0; 156db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab } 157db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 158724e2495502a98aaa3f93c404472a991da8ff857David Härdemanout: 159e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman IR_dprintk(1, "RC5(x) decode failed at state %i (%uus %s)\n", 160e40b1127f994a427568319d1be9b9e5ab1f58dd1David Härdeman data->state, TO_US(ev.duration), TO_STR(ev.pulse)); 161db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab data->state = STATE_INACTIVE; 162db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab return -EINVAL; 163db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab} 164db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 165db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehabstatic struct ir_raw_handler rc5_handler = { 166667c9ebe97f7e5f1e48e7eb321644c6fb1668de5David Härdeman .protocols = IR_TYPE_RC5, 167db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab .decode = ir_rc5_decode, 168db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab}; 169db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 170db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehabstatic int __init ir_rc5_decode_init(void) 171db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab{ 172db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab ir_raw_handler_register(&rc5_handler); 173db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 174733419b5c4d29186006982a9a27227e214a39dbcDavid Härdeman printk(KERN_INFO "IR RC5(x) protocol handler initialized\n"); 175db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab return 0; 176db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab} 177db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 178db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehabstatic void __exit ir_rc5_decode_exit(void) 179db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab{ 180db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab ir_raw_handler_unregister(&rc5_handler); 181db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab} 182db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 183db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehabmodule_init(ir_rc5_decode_init); 184db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehabmodule_exit(ir_rc5_decode_exit); 185db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho Chehab 186db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho ChehabMODULE_LICENSE("GPL"); 187db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho ChehabMODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>"); 188db1423a6c79f66db2b1846614c13bde9c2db7ad2Mauro Carvalho ChehabMODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)"); 189733419b5c4d29186006982a9a27227e214a39dbcDavid HärdemanMODULE_DESCRIPTION("RC5(x) IR protocol decoder"); 190