256 lines · c
1// SPDX-License-Identifier: GPL-2.0+2// ir-rcmm-decoder.c - A decoder for the RCMM IR protocol3//4// Copyright (C) 2018 by Patrick Lerda <patrick9876@free.fr>5 6#include "rc-core-priv.h"7#include <linux/module.h>8 9#define RCMM_UNIT 166 /* microseconds */10#define RCMM_PREFIX_PULSE 417 /* 166.666666666666*2.5 */11#define RCMM_PULSE_0 278 /* 166.666666666666*(1+2/3) */12#define RCMM_PULSE_1 444 /* 166.666666666666*(2+2/3) */13#define RCMM_PULSE_2 611 /* 166.666666666666*(3+2/3) */14#define RCMM_PULSE_3 778 /* 166.666666666666*(4+2/3) */15 16enum rcmm_state {17 STATE_INACTIVE,18 STATE_LOW,19 STATE_BUMP,20 STATE_VALUE,21 STATE_FINISHED,22};23 24static bool rcmm_mode(const struct rcmm_dec *data)25{26 return !((0x000c0000 & data->bits) == 0x000c0000);27}28 29static int rcmm_miscmode(struct rc_dev *dev, struct rcmm_dec *data)30{31 switch (data->count) {32 case 24:33 if (dev->enabled_protocols & RC_PROTO_BIT_RCMM24) {34 rc_keydown(dev, RC_PROTO_RCMM24, data->bits, 0);35 data->state = STATE_INACTIVE;36 return 0;37 }38 return -1;39 40 case 12:41 if (dev->enabled_protocols & RC_PROTO_BIT_RCMM12) {42 rc_keydown(dev, RC_PROTO_RCMM12, data->bits, 0);43 data->state = STATE_INACTIVE;44 return 0;45 }46 return -1;47 }48 49 return -1;50}51 52/**53 * ir_rcmm_decode() - Decode one RCMM pulse or space54 * @dev: the struct rc_dev descriptor of the device55 * @ev: the struct ir_raw_event descriptor of the pulse/space56 *57 * This function returns -EINVAL if the pulse violates the state machine58 */59static int ir_rcmm_decode(struct rc_dev *dev, struct ir_raw_event ev)60{61 struct rcmm_dec *data = &dev->raw->rcmm;62 u32 scancode;63 u8 toggle;64 int value;65 66 if (!(dev->enabled_protocols & (RC_PROTO_BIT_RCMM32 |67 RC_PROTO_BIT_RCMM24 |68 RC_PROTO_BIT_RCMM12)))69 return 0;70 71 if (!is_timing_event(ev)) {72 if (ev.overflow)73 data->state = STATE_INACTIVE;74 return 0;75 }76 77 switch (data->state) {78 case STATE_INACTIVE:79 if (!ev.pulse)80 break;81 82 if (!eq_margin(ev.duration, RCMM_PREFIX_PULSE, RCMM_UNIT))83 break;84 85 data->state = STATE_LOW;86 data->count = 0;87 data->bits = 0;88 return 0;89 90 case STATE_LOW:91 if (ev.pulse)92 break;93 94 if (!eq_margin(ev.duration, RCMM_PULSE_0, RCMM_UNIT))95 break;96 97 data->state = STATE_BUMP;98 return 0;99 100 case STATE_BUMP:101 if (!ev.pulse)102 break;103 104 if (!eq_margin(ev.duration, RCMM_UNIT, RCMM_UNIT / 2))105 break;106 107 data->state = STATE_VALUE;108 return 0;109 110 case STATE_VALUE:111 if (ev.pulse)112 break;113 114 if (eq_margin(ev.duration, RCMM_PULSE_0, RCMM_UNIT / 2))115 value = 0;116 else if (eq_margin(ev.duration, RCMM_PULSE_1, RCMM_UNIT / 2))117 value = 1;118 else if (eq_margin(ev.duration, RCMM_PULSE_2, RCMM_UNIT / 2))119 value = 2;120 else if (eq_margin(ev.duration, RCMM_PULSE_3, RCMM_UNIT / 2))121 value = 3;122 else123 value = -1;124 125 if (value == -1) {126 if (!rcmm_miscmode(dev, data))127 return 0;128 break;129 }130 131 data->bits <<= 2;132 data->bits |= value;133 134 data->count += 2;135 136 if (data->count < 32)137 data->state = STATE_BUMP;138 else139 data->state = STATE_FINISHED;140 141 return 0;142 143 case STATE_FINISHED:144 if (!ev.pulse)145 break;146 147 if (!eq_margin(ev.duration, RCMM_UNIT, RCMM_UNIT / 2))148 break;149 150 if (rcmm_mode(data)) {151 toggle = !!(0x8000 & data->bits);152 scancode = data->bits & ~0x8000;153 } else {154 toggle = 0;155 scancode = data->bits;156 }157 158 if (dev->enabled_protocols & RC_PROTO_BIT_RCMM32) {159 rc_keydown(dev, RC_PROTO_RCMM32, scancode, toggle);160 data->state = STATE_INACTIVE;161 return 0;162 }163 164 break;165 }166 167 dev_dbg(&dev->dev, "RC-MM decode failed at count %d state %d (%uus %s)\n",168 data->count, data->state, ev.duration, TO_STR(ev.pulse));169 data->state = STATE_INACTIVE;170 return -EINVAL;171}172 173static const int rcmmspace[] = {174 RCMM_PULSE_0,175 RCMM_PULSE_1,176 RCMM_PULSE_2,177 RCMM_PULSE_3,178};179 180static int ir_rcmm_rawencoder(struct ir_raw_event **ev, unsigned int max,181 unsigned int n, u32 data)182{183 int i;184 int ret;185 186 ret = ir_raw_gen_pulse_space(ev, &max, RCMM_PREFIX_PULSE, RCMM_PULSE_0);187 if (ret)188 return ret;189 190 for (i = n - 2; i >= 0; i -= 2) {191 const unsigned int space = rcmmspace[(data >> i) & 3];192 193 ret = ir_raw_gen_pulse_space(ev, &max, RCMM_UNIT, space);194 if (ret)195 return ret;196 }197 198 return ir_raw_gen_pulse_space(ev, &max, RCMM_UNIT, RCMM_PULSE_3 * 2);199}200 201static int ir_rcmm_encode(enum rc_proto protocol, u32 scancode,202 struct ir_raw_event *events, unsigned int max)203{204 struct ir_raw_event *e = events;205 int ret;206 207 switch (protocol) {208 case RC_PROTO_RCMM32:209 ret = ir_rcmm_rawencoder(&e, max, 32, scancode);210 break;211 case RC_PROTO_RCMM24:212 ret = ir_rcmm_rawencoder(&e, max, 24, scancode);213 break;214 case RC_PROTO_RCMM12:215 ret = ir_rcmm_rawencoder(&e, max, 12, scancode);216 break;217 default:218 ret = -EINVAL;219 }220 221 if (ret < 0)222 return ret;223 224 return e - events;225}226 227static struct ir_raw_handler rcmm_handler = {228 .protocols = RC_PROTO_BIT_RCMM32 |229 RC_PROTO_BIT_RCMM24 |230 RC_PROTO_BIT_RCMM12,231 .decode = ir_rcmm_decode,232 .encode = ir_rcmm_encode,233 .carrier = 36000,234 .min_timeout = RCMM_PULSE_3 + RCMM_UNIT,235};236 237static int __init ir_rcmm_decode_init(void)238{239 ir_raw_handler_register(&rcmm_handler);240 241 pr_info("IR RCMM protocol handler initialized\n");242 return 0;243}244 245static void __exit ir_rcmm_decode_exit(void)246{247 ir_raw_handler_unregister(&rcmm_handler);248}249 250module_init(ir_rcmm_decode_init);251module_exit(ir_rcmm_decode_exit);252 253MODULE_LICENSE("GPL");254MODULE_AUTHOR("Patrick Lerda");255MODULE_DESCRIPTION("RCMM IR protocol decoder");256