132cf86f6SMauro Carvalho Chehab /* ir-nec-decoder.c - handle NEC IR Pulse/Space protocol 232cf86f6SMauro Carvalho Chehab * 332cf86f6SMauro Carvalho Chehab * Copyright (C) 2010 by Mauro Carvalho Chehab <mchehab@redhat.com> 432cf86f6SMauro Carvalho Chehab * 532cf86f6SMauro Carvalho Chehab * This program is free software; you can redistribute it and/or modify 632cf86f6SMauro Carvalho Chehab * it under the terms of the GNU General Public License as published by 732cf86f6SMauro Carvalho Chehab * the Free Software Foundation version 2 of the License. 832cf86f6SMauro Carvalho Chehab * 932cf86f6SMauro Carvalho Chehab * This program is distributed in the hope that it will be useful, 1032cf86f6SMauro Carvalho Chehab * but WITHOUT ANY WARRANTY; without even the implied warranty of 1132cf86f6SMauro Carvalho Chehab * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 1232cf86f6SMauro Carvalho Chehab * GNU General Public License for more details. 1332cf86f6SMauro Carvalho Chehab */ 1432cf86f6SMauro Carvalho Chehab 1532cf86f6SMauro Carvalho Chehab #include <linux/bitrev.h> 16f62de675SMauro Carvalho Chehab #include "rc-core-priv.h" 1732cf86f6SMauro Carvalho Chehab 1832cf86f6SMauro Carvalho Chehab #define NEC_NBITS 32 1932cf86f6SMauro Carvalho Chehab #define NEC_UNIT 562500 /* ns */ 2032cf86f6SMauro Carvalho Chehab #define NEC_HEADER_PULSE (16 * NEC_UNIT) 2132cf86f6SMauro Carvalho Chehab #define NECX_HEADER_PULSE (8 * NEC_UNIT) /* Less common NEC variant */ 2232cf86f6SMauro Carvalho Chehab #define NEC_HEADER_SPACE (8 * NEC_UNIT) 2332cf86f6SMauro Carvalho Chehab #define NEC_REPEAT_SPACE (4 * NEC_UNIT) 2432cf86f6SMauro Carvalho Chehab #define NEC_BIT_PULSE (1 * NEC_UNIT) 2532cf86f6SMauro Carvalho Chehab #define NEC_BIT_0_SPACE (1 * NEC_UNIT) 2632cf86f6SMauro Carvalho Chehab #define NEC_BIT_1_SPACE (3 * NEC_UNIT) 2732cf86f6SMauro Carvalho Chehab #define NEC_TRAILER_PULSE (1 * NEC_UNIT) 2832cf86f6SMauro Carvalho Chehab #define NEC_TRAILER_SPACE (10 * NEC_UNIT) /* even longer in reality */ 2932cf86f6SMauro Carvalho Chehab #define NECX_REPEAT_BITS 1 3032cf86f6SMauro Carvalho Chehab 3132cf86f6SMauro Carvalho Chehab enum nec_state { 3232cf86f6SMauro Carvalho Chehab STATE_INACTIVE, 3332cf86f6SMauro Carvalho Chehab STATE_HEADER_SPACE, 3432cf86f6SMauro Carvalho Chehab STATE_BIT_PULSE, 3532cf86f6SMauro Carvalho Chehab STATE_BIT_SPACE, 3632cf86f6SMauro Carvalho Chehab STATE_TRAILER_PULSE, 3732cf86f6SMauro Carvalho Chehab STATE_TRAILER_SPACE, 3832cf86f6SMauro Carvalho Chehab }; 3932cf86f6SMauro Carvalho Chehab 4032cf86f6SMauro Carvalho Chehab /** 4132cf86f6SMauro Carvalho Chehab * ir_nec_decode() - Decode one NEC pulse or space 4232cf86f6SMauro Carvalho Chehab * @input_dev: the struct input_dev descriptor of the device 4332cf86f6SMauro Carvalho Chehab * @duration: the struct ir_raw_event descriptor of the pulse/space 4432cf86f6SMauro Carvalho Chehab * 4532cf86f6SMauro Carvalho Chehab * This function returns -EINVAL if the pulse violates the state machine 4632cf86f6SMauro Carvalho Chehab */ 4732cf86f6SMauro Carvalho Chehab static int ir_nec_decode(struct input_dev *input_dev, struct ir_raw_event ev) 4832cf86f6SMauro Carvalho Chehab { 4932cf86f6SMauro Carvalho Chehab struct ir_input_dev *ir_dev = input_get_drvdata(input_dev); 5032cf86f6SMauro Carvalho Chehab struct nec_dec *data = &ir_dev->raw->nec; 5132cf86f6SMauro Carvalho Chehab u32 scancode; 5232cf86f6SMauro Carvalho Chehab u8 address, not_address, command, not_command; 5332cf86f6SMauro Carvalho Chehab 5432cf86f6SMauro Carvalho Chehab if (!(ir_dev->raw->enabled_protocols & IR_TYPE_NEC)) 5532cf86f6SMauro Carvalho Chehab return 0; 5632cf86f6SMauro Carvalho Chehab 5732cf86f6SMauro Carvalho Chehab if (!is_timing_event(ev)) { 5832cf86f6SMauro Carvalho Chehab if (ev.reset) 5932cf86f6SMauro Carvalho Chehab data->state = STATE_INACTIVE; 6032cf86f6SMauro Carvalho Chehab return 0; 6132cf86f6SMauro Carvalho Chehab } 6232cf86f6SMauro Carvalho Chehab 6332cf86f6SMauro Carvalho Chehab IR_dprintk(2, "NEC decode started at state %d (%uus %s)\n", 6432cf86f6SMauro Carvalho Chehab data->state, TO_US(ev.duration), TO_STR(ev.pulse)); 6532cf86f6SMauro Carvalho Chehab 6632cf86f6SMauro Carvalho Chehab switch (data->state) { 6732cf86f6SMauro Carvalho Chehab 6832cf86f6SMauro Carvalho Chehab case STATE_INACTIVE: 6932cf86f6SMauro Carvalho Chehab if (!ev.pulse) 7032cf86f6SMauro Carvalho Chehab break; 7132cf86f6SMauro Carvalho Chehab 7232cf86f6SMauro Carvalho Chehab if (eq_margin(ev.duration, NEC_HEADER_PULSE, NEC_UNIT / 2)) { 7332cf86f6SMauro Carvalho Chehab data->is_nec_x = false; 7432cf86f6SMauro Carvalho Chehab data->necx_repeat = false; 7532cf86f6SMauro Carvalho Chehab } else if (eq_margin(ev.duration, NECX_HEADER_PULSE, NEC_UNIT / 2)) 7632cf86f6SMauro Carvalho Chehab data->is_nec_x = true; 7732cf86f6SMauro Carvalho Chehab else 7832cf86f6SMauro Carvalho Chehab break; 7932cf86f6SMauro Carvalho Chehab 8032cf86f6SMauro Carvalho Chehab data->count = 0; 8132cf86f6SMauro Carvalho Chehab data->state = STATE_HEADER_SPACE; 8232cf86f6SMauro Carvalho Chehab return 0; 8332cf86f6SMauro Carvalho Chehab 8432cf86f6SMauro Carvalho Chehab case STATE_HEADER_SPACE: 8532cf86f6SMauro Carvalho Chehab if (ev.pulse) 8632cf86f6SMauro Carvalho Chehab break; 8732cf86f6SMauro Carvalho Chehab 8832cf86f6SMauro Carvalho Chehab if (eq_margin(ev.duration, NEC_HEADER_SPACE, NEC_UNIT / 2)) { 8932cf86f6SMauro Carvalho Chehab data->state = STATE_BIT_PULSE; 9032cf86f6SMauro Carvalho Chehab return 0; 9132cf86f6SMauro Carvalho Chehab } else if (eq_margin(ev.duration, NEC_REPEAT_SPACE, NEC_UNIT / 2)) { 9232cf86f6SMauro Carvalho Chehab ir_repeat(input_dev); 9332cf86f6SMauro Carvalho Chehab IR_dprintk(1, "Repeat last key\n"); 9432cf86f6SMauro Carvalho Chehab data->state = STATE_TRAILER_PULSE; 9532cf86f6SMauro Carvalho Chehab return 0; 9632cf86f6SMauro Carvalho Chehab } 9732cf86f6SMauro Carvalho Chehab 9832cf86f6SMauro Carvalho Chehab break; 9932cf86f6SMauro Carvalho Chehab 10032cf86f6SMauro Carvalho Chehab case STATE_BIT_PULSE: 10132cf86f6SMauro Carvalho Chehab if (!ev.pulse) 10232cf86f6SMauro Carvalho Chehab break; 10332cf86f6SMauro Carvalho Chehab 10432cf86f6SMauro Carvalho Chehab if (!eq_margin(ev.duration, NEC_BIT_PULSE, NEC_UNIT / 2)) 10532cf86f6SMauro Carvalho Chehab break; 10632cf86f6SMauro Carvalho Chehab 10732cf86f6SMauro Carvalho Chehab data->state = STATE_BIT_SPACE; 10832cf86f6SMauro Carvalho Chehab return 0; 10932cf86f6SMauro Carvalho Chehab 11032cf86f6SMauro Carvalho Chehab case STATE_BIT_SPACE: 11132cf86f6SMauro Carvalho Chehab if (ev.pulse) 11232cf86f6SMauro Carvalho Chehab break; 11332cf86f6SMauro Carvalho Chehab 11432cf86f6SMauro Carvalho Chehab if (data->necx_repeat && data->count == NECX_REPEAT_BITS && 11532cf86f6SMauro Carvalho Chehab geq_margin(ev.duration, 11632cf86f6SMauro Carvalho Chehab NEC_TRAILER_SPACE, NEC_UNIT / 2)) { 11732cf86f6SMauro Carvalho Chehab IR_dprintk(1, "Repeat last key\n"); 11832cf86f6SMauro Carvalho Chehab ir_repeat(input_dev); 11932cf86f6SMauro Carvalho Chehab data->state = STATE_INACTIVE; 12032cf86f6SMauro Carvalho Chehab return 0; 12132cf86f6SMauro Carvalho Chehab 12232cf86f6SMauro Carvalho Chehab } else if (data->count > NECX_REPEAT_BITS) 12332cf86f6SMauro Carvalho Chehab data->necx_repeat = false; 12432cf86f6SMauro Carvalho Chehab 12532cf86f6SMauro Carvalho Chehab data->bits <<= 1; 12632cf86f6SMauro Carvalho Chehab if (eq_margin(ev.duration, NEC_BIT_1_SPACE, NEC_UNIT / 2)) 12732cf86f6SMauro Carvalho Chehab data->bits |= 1; 12832cf86f6SMauro Carvalho Chehab else if (!eq_margin(ev.duration, NEC_BIT_0_SPACE, NEC_UNIT / 2)) 12932cf86f6SMauro Carvalho Chehab break; 13032cf86f6SMauro Carvalho Chehab data->count++; 13132cf86f6SMauro Carvalho Chehab 13232cf86f6SMauro Carvalho Chehab if (data->count == NEC_NBITS) 13332cf86f6SMauro Carvalho Chehab data->state = STATE_TRAILER_PULSE; 13432cf86f6SMauro Carvalho Chehab else 13532cf86f6SMauro Carvalho Chehab data->state = STATE_BIT_PULSE; 13632cf86f6SMauro Carvalho Chehab 13732cf86f6SMauro Carvalho Chehab return 0; 13832cf86f6SMauro Carvalho Chehab 13932cf86f6SMauro Carvalho Chehab case STATE_TRAILER_PULSE: 14032cf86f6SMauro Carvalho Chehab if (!ev.pulse) 14132cf86f6SMauro Carvalho Chehab break; 14232cf86f6SMauro Carvalho Chehab 14332cf86f6SMauro Carvalho Chehab if (!eq_margin(ev.duration, NEC_TRAILER_PULSE, NEC_UNIT / 2)) 14432cf86f6SMauro Carvalho Chehab break; 14532cf86f6SMauro Carvalho Chehab 14632cf86f6SMauro Carvalho Chehab data->state = STATE_TRAILER_SPACE; 14732cf86f6SMauro Carvalho Chehab return 0; 14832cf86f6SMauro Carvalho Chehab 14932cf86f6SMauro Carvalho Chehab case STATE_TRAILER_SPACE: 15032cf86f6SMauro Carvalho Chehab if (ev.pulse) 15132cf86f6SMauro Carvalho Chehab break; 15232cf86f6SMauro Carvalho Chehab 15332cf86f6SMauro Carvalho Chehab if (!geq_margin(ev.duration, NEC_TRAILER_SPACE, NEC_UNIT / 2)) 15432cf86f6SMauro Carvalho Chehab break; 15532cf86f6SMauro Carvalho Chehab 15632cf86f6SMauro Carvalho Chehab address = bitrev8((data->bits >> 24) & 0xff); 15732cf86f6SMauro Carvalho Chehab not_address = bitrev8((data->bits >> 16) & 0xff); 15832cf86f6SMauro Carvalho Chehab command = bitrev8((data->bits >> 8) & 0xff); 15932cf86f6SMauro Carvalho Chehab not_command = bitrev8((data->bits >> 0) & 0xff); 16032cf86f6SMauro Carvalho Chehab 16132cf86f6SMauro Carvalho Chehab if ((command ^ not_command) != 0xff) { 16232cf86f6SMauro Carvalho Chehab IR_dprintk(1, "NEC checksum error: received 0x%08x\n", 16332cf86f6SMauro Carvalho Chehab data->bits); 16432cf86f6SMauro Carvalho Chehab break; 16532cf86f6SMauro Carvalho Chehab } 16632cf86f6SMauro Carvalho Chehab 16732cf86f6SMauro Carvalho Chehab if ((address ^ not_address) != 0xff) { 16832cf86f6SMauro Carvalho Chehab /* Extended NEC */ 16932cf86f6SMauro Carvalho Chehab scancode = address << 16 | 17032cf86f6SMauro Carvalho Chehab not_address << 8 | 17132cf86f6SMauro Carvalho Chehab command; 17232cf86f6SMauro Carvalho Chehab IR_dprintk(1, "NEC (Ext) scancode 0x%06x\n", scancode); 17332cf86f6SMauro Carvalho Chehab } else { 17432cf86f6SMauro Carvalho Chehab /* Normal NEC */ 17532cf86f6SMauro Carvalho Chehab scancode = address << 8 | command; 17632cf86f6SMauro Carvalho Chehab IR_dprintk(1, "NEC scancode 0x%04x\n", scancode); 17732cf86f6SMauro Carvalho Chehab } 17832cf86f6SMauro Carvalho Chehab 17932cf86f6SMauro Carvalho Chehab if (data->is_nec_x) 18032cf86f6SMauro Carvalho Chehab data->necx_repeat = true; 18132cf86f6SMauro Carvalho Chehab 18232cf86f6SMauro Carvalho Chehab ir_keydown(input_dev, scancode, 0); 18332cf86f6SMauro Carvalho Chehab data->state = STATE_INACTIVE; 18432cf86f6SMauro Carvalho Chehab return 0; 18532cf86f6SMauro Carvalho Chehab } 18632cf86f6SMauro Carvalho Chehab 18732cf86f6SMauro Carvalho Chehab IR_dprintk(1, "NEC decode failed at state %d (%uus %s)\n", 18832cf86f6SMauro Carvalho Chehab data->state, TO_US(ev.duration), TO_STR(ev.pulse)); 18932cf86f6SMauro Carvalho Chehab data->state = STATE_INACTIVE; 19032cf86f6SMauro Carvalho Chehab return -EINVAL; 19132cf86f6SMauro Carvalho Chehab } 19232cf86f6SMauro Carvalho Chehab 19332cf86f6SMauro Carvalho Chehab static struct ir_raw_handler nec_handler = { 19432cf86f6SMauro Carvalho Chehab .protocols = IR_TYPE_NEC, 19532cf86f6SMauro Carvalho Chehab .decode = ir_nec_decode, 19632cf86f6SMauro Carvalho Chehab }; 19732cf86f6SMauro Carvalho Chehab 19832cf86f6SMauro Carvalho Chehab static int __init ir_nec_decode_init(void) 19932cf86f6SMauro Carvalho Chehab { 20032cf86f6SMauro Carvalho Chehab ir_raw_handler_register(&nec_handler); 20132cf86f6SMauro Carvalho Chehab 20232cf86f6SMauro Carvalho Chehab printk(KERN_INFO "IR NEC protocol handler initialized\n"); 20332cf86f6SMauro Carvalho Chehab return 0; 20432cf86f6SMauro Carvalho Chehab } 20532cf86f6SMauro Carvalho Chehab 20632cf86f6SMauro Carvalho Chehab static void __exit ir_nec_decode_exit(void) 20732cf86f6SMauro Carvalho Chehab { 20832cf86f6SMauro Carvalho Chehab ir_raw_handler_unregister(&nec_handler); 20932cf86f6SMauro Carvalho Chehab } 21032cf86f6SMauro Carvalho Chehab 21132cf86f6SMauro Carvalho Chehab module_init(ir_nec_decode_init); 21232cf86f6SMauro Carvalho Chehab module_exit(ir_nec_decode_exit); 21332cf86f6SMauro Carvalho Chehab 21432cf86f6SMauro Carvalho Chehab MODULE_LICENSE("GPL"); 21532cf86f6SMauro Carvalho Chehab MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>"); 21632cf86f6SMauro Carvalho Chehab MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)"); 21732cf86f6SMauro Carvalho Chehab MODULE_DESCRIPTION("NEC IR protocol decoder"); 218