1 // SPDX-License-Identifier: GPL-2.0-only 2 /* ir-mce_kbd-decoder.c - A decoder for the RC6-ish keyboard/mouse IR protocol 3 * used by the Microsoft Remote Keyboard for Windows Media Center Edition, 4 * referred to by Microsoft's Windows Media Center remote specification docs 5 * as "an internal protocol called MCIR-2". 6 * 7 * Copyright (C) 2011 by Jarod Wilson <jarod@redhat.com> 8 */ 9 #include <linux/module.h> 10 11 #include "rc-core-priv.h" 12 13 /* 14 * This decoder currently supports: 15 * - MCIR-2 29-bit IR signals used for mouse movement and buttons 16 * - MCIR-2 32-bit IR signals used for standard keyboard keys 17 * 18 * The media keys on the keyboard send RC-6 signals that are indistinguishable 19 * from the keys of the same name on the stock MCE remote, and will be handled 20 * by the standard RC-6 decoder, and be made available to the system via the 21 * input device for the remote, rather than the keyboard/mouse one. 22 */ 23 24 #define MCIR2_UNIT 333 /* us */ 25 #define MCIR2_HEADER_NBITS 5 26 #define MCIR2_MOUSE_NBITS 29 27 #define MCIR2_KEYBOARD_NBITS 32 28 #define MCIR2_PREFIX_PULSE (8 * MCIR2_UNIT) 29 #define MCIR2_PREFIX_SPACE (1 * MCIR2_UNIT) 30 #define MCIR2_MAX_LEN (3 * MCIR2_UNIT) 31 #define MCIR2_BIT_START (1 * MCIR2_UNIT) 32 #define MCIR2_BIT_END (1 * MCIR2_UNIT) 33 #define MCIR2_BIT_0 (1 * MCIR2_UNIT) 34 #define MCIR2_BIT_SET (2 * MCIR2_UNIT) 35 #define MCIR2_MODE_MASK 0xf /* for the header bits */ 36 #define MCIR2_KEYBOARD_HEADER 0x4 37 #define MCIR2_MOUSE_HEADER 0x1 38 #define MCIR2_MASK_KEYS_START 0xe0 39 40 enum mce_kbd_mode { 41 MCIR2_MODE_KEYBOARD, 42 MCIR2_MODE_MOUSE, 43 MCIR2_MODE_UNKNOWN, 44 }; 45 46 enum mce_kbd_state { 47 STATE_INACTIVE, 48 STATE_HEADER_BIT_START, 49 STATE_HEADER_BIT_END, 50 STATE_BODY_BIT_START, 51 STATE_BODY_BIT_END, 52 STATE_FINISHED, 53 }; 54 55 static unsigned char kbd_keycodes[256] = { 56 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_A, 57 KEY_B, KEY_C, KEY_D, KEY_E, KEY_F, 58 KEY_G, KEY_H, KEY_I, KEY_J, KEY_K, 59 KEY_L, KEY_M, KEY_N, KEY_O, KEY_P, 60 KEY_Q, KEY_R, KEY_S, KEY_T, KEY_U, 61 KEY_V, KEY_W, KEY_X, KEY_Y, KEY_Z, 62 KEY_1, KEY_2, KEY_3, KEY_4, KEY_5, 63 KEY_6, KEY_7, KEY_8, KEY_9, KEY_0, 64 KEY_ENTER, KEY_ESC, KEY_BACKSPACE, KEY_TAB, KEY_SPACE, 65 KEY_MINUS, KEY_EQUAL, KEY_LEFTBRACE, KEY_RIGHTBRACE, KEY_BACKSLASH, 66 KEY_BACKSLASH, KEY_SEMICOLON, KEY_APOSTROPHE, KEY_GRAVE, KEY_COMMA, 67 KEY_DOT, KEY_SLASH, KEY_CAPSLOCK, KEY_F1, KEY_F2, 68 KEY_F3, KEY_F4, KEY_F5, KEY_F6, KEY_F7, 69 KEY_F8, KEY_F9, KEY_F10, KEY_F11, KEY_F12, 70 KEY_SYSRQ, KEY_SCROLLLOCK, KEY_PAUSE, KEY_INSERT, KEY_HOME, 71 KEY_PAGEUP, KEY_DELETE, KEY_END, KEY_PAGEDOWN, KEY_RIGHT, 72 KEY_LEFT, KEY_DOWN, KEY_UP, KEY_NUMLOCK, KEY_KPSLASH, 73 KEY_KPASTERISK, KEY_KPMINUS, KEY_KPPLUS, KEY_KPENTER, KEY_KP1, 74 KEY_KP2, KEY_KP3, KEY_KP4, KEY_KP5, KEY_KP6, 75 KEY_KP7, KEY_KP8, KEY_KP9, KEY_KP0, KEY_KPDOT, 76 KEY_102ND, KEY_COMPOSE, KEY_POWER, KEY_KPEQUAL, KEY_F13, 77 KEY_F14, KEY_F15, KEY_F16, KEY_F17, KEY_F18, 78 KEY_F19, KEY_F20, KEY_F21, KEY_F22, KEY_F23, 79 KEY_F24, KEY_OPEN, KEY_HELP, KEY_PROPS, KEY_FRONT, 80 KEY_STOP, KEY_AGAIN, KEY_UNDO, KEY_CUT, KEY_COPY, 81 KEY_PASTE, KEY_FIND, KEY_MUTE, KEY_VOLUMEUP, KEY_VOLUMEDOWN, 82 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_KPCOMMA, KEY_RESERVED, 83 KEY_RO, KEY_KATAKANAHIRAGANA, KEY_YEN, KEY_HENKAN, KEY_MUHENKAN, 84 KEY_KPJPCOMMA, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_HANGUEL, 85 KEY_HANJA, KEY_KATAKANA, KEY_HIRAGANA, KEY_ZENKAKUHANKAKU, KEY_RESERVED, 86 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, 87 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, 88 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, 89 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, 90 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, 91 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, 92 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, 93 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, 94 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, 95 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, 96 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, 97 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, 98 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, 99 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, 100 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_LEFTCTRL, 101 KEY_LEFTSHIFT, KEY_LEFTALT, KEY_LEFTMETA, KEY_RIGHTCTRL, KEY_RIGHTSHIFT, 102 KEY_RIGHTALT, KEY_RIGHTMETA, KEY_PLAYPAUSE, KEY_STOPCD, KEY_PREVIOUSSONG, 103 KEY_NEXTSONG, KEY_EJECTCD, KEY_VOLUMEUP, KEY_VOLUMEDOWN, KEY_MUTE, 104 KEY_WWW, KEY_BACK, KEY_FORWARD, KEY_STOP, KEY_FIND, 105 KEY_SCROLLUP, KEY_SCROLLDOWN, KEY_EDIT, KEY_SLEEP, KEY_COFFEE, 106 KEY_REFRESH, KEY_CALC, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, 107 KEY_RESERVED 108 }; 109 110 static void mce_kbd_rx_timeout(struct timer_list *t) 111 { 112 struct ir_raw_event_ctrl *raw = timer_container_of(raw, t, 113 mce_kbd.rx_timeout); 114 unsigned char maskcode; 115 unsigned long flags; 116 int i; 117 118 dev_dbg(&raw->dev->dev, "timer callback clearing all keys\n"); 119 120 spin_lock_irqsave(&raw->mce_kbd.keylock, flags); 121 122 if (time_is_before_eq_jiffies(raw->mce_kbd.rx_timeout.expires)) { 123 for (i = 0; i < 7; i++) { 124 maskcode = kbd_keycodes[MCIR2_MASK_KEYS_START + i]; 125 input_report_key(raw->dev->input_dev, maskcode, 0); 126 } 127 128 for (i = 0; i < MCIR2_MASK_KEYS_START; i++) 129 input_report_key(raw->dev->input_dev, kbd_keycodes[i], 130 0); 131 132 input_sync(raw->dev->input_dev); 133 } 134 spin_unlock_irqrestore(&raw->mce_kbd.keylock, flags); 135 } 136 137 static enum mce_kbd_mode mce_kbd_mode(struct mce_kbd_dec *data) 138 { 139 switch (data->header & MCIR2_MODE_MASK) { 140 case MCIR2_KEYBOARD_HEADER: 141 return MCIR2_MODE_KEYBOARD; 142 case MCIR2_MOUSE_HEADER: 143 return MCIR2_MODE_MOUSE; 144 default: 145 return MCIR2_MODE_UNKNOWN; 146 } 147 } 148 149 static void ir_mce_kbd_process_keyboard_data(struct rc_dev *dev, u32 scancode) 150 { 151 u8 keydata1 = (scancode >> 8) & 0xff; 152 u8 keydata2 = (scancode >> 16) & 0xff; 153 u8 shiftmask = scancode & 0xff; 154 unsigned char maskcode; 155 int i, keystate; 156 157 dev_dbg(&dev->dev, "keyboard: keydata2 = 0x%02x, keydata1 = 0x%02x, shiftmask = 0x%02x\n", 158 keydata2, keydata1, shiftmask); 159 160 for (i = 0; i < 7; i++) { 161 maskcode = kbd_keycodes[MCIR2_MASK_KEYS_START + i]; 162 if (shiftmask & (1 << i)) 163 keystate = 1; 164 else 165 keystate = 0; 166 input_report_key(dev->input_dev, maskcode, keystate); 167 } 168 169 if (keydata1) 170 input_report_key(dev->input_dev, kbd_keycodes[keydata1], 1); 171 if (keydata2) 172 input_report_key(dev->input_dev, kbd_keycodes[keydata2], 1); 173 174 if (!keydata1 && !keydata2) { 175 for (i = 0; i < MCIR2_MASK_KEYS_START; i++) 176 input_report_key(dev->input_dev, kbd_keycodes[i], 0); 177 } 178 } 179 180 static void ir_mce_kbd_process_mouse_data(struct rc_dev *dev, u32 scancode) 181 { 182 /* raw mouse coordinates */ 183 u8 xdata = (scancode >> 7) & 0x7f; 184 u8 ydata = (scancode >> 14) & 0x7f; 185 int x, y; 186 /* mouse buttons */ 187 bool right = scancode & 0x40; 188 bool left = scancode & 0x20; 189 190 if (xdata & 0x40) 191 x = -((~xdata & 0x7f) + 1); 192 else 193 x = xdata; 194 195 if (ydata & 0x40) 196 y = -((~ydata & 0x7f) + 1); 197 else 198 y = ydata; 199 200 dev_dbg(&dev->dev, "mouse: x = %d, y = %d, btns = %s%s\n", 201 x, y, left ? "L" : "", right ? "R" : ""); 202 203 input_report_rel(dev->input_dev, REL_X, x); 204 input_report_rel(dev->input_dev, REL_Y, y); 205 206 input_report_key(dev->input_dev, BTN_LEFT, left); 207 input_report_key(dev->input_dev, BTN_RIGHT, right); 208 } 209 210 /** 211 * ir_mce_kbd_decode() - Decode one mce_kbd pulse or space 212 * @dev: the struct rc_dev descriptor of the device 213 * @ev: the struct ir_raw_event descriptor of the pulse/space 214 * 215 * This function returns -EINVAL if the pulse violates the state machine 216 */ 217 static int ir_mce_kbd_decode(struct rc_dev *dev, struct ir_raw_event ev) 218 { 219 struct mce_kbd_dec *data = &dev->raw->mce_kbd; 220 u32 scancode; 221 unsigned long delay; 222 struct lirc_scancode lsc = {}; 223 224 if (!is_timing_event(ev)) { 225 if (ev.overflow) 226 data->state = STATE_INACTIVE; 227 return 0; 228 } 229 230 if (!geq_margin(ev.duration, MCIR2_UNIT, MCIR2_UNIT / 2)) 231 goto out; 232 233 again: 234 dev_dbg(&dev->dev, "started at state %i (%uus %s)\n", 235 data->state, ev.duration, TO_STR(ev.pulse)); 236 237 if (!geq_margin(ev.duration, MCIR2_UNIT, MCIR2_UNIT / 2)) 238 return 0; 239 240 switch (data->state) { 241 242 case STATE_INACTIVE: 243 if (!ev.pulse) 244 break; 245 246 /* Note: larger margin on first pulse since each MCIR2_UNIT 247 is quite short and some hardware takes some time to 248 adjust to the signal */ 249 if (!eq_margin(ev.duration, MCIR2_PREFIX_PULSE, MCIR2_UNIT)) 250 break; 251 252 data->state = STATE_HEADER_BIT_START; 253 data->count = 0; 254 data->header = 0; 255 return 0; 256 257 case STATE_HEADER_BIT_START: 258 if (geq_margin(ev.duration, MCIR2_MAX_LEN, MCIR2_UNIT / 2)) 259 break; 260 261 data->header <<= 1; 262 if (ev.pulse) 263 data->header |= 1; 264 data->count++; 265 data->state = STATE_HEADER_BIT_END; 266 return 0; 267 268 case STATE_HEADER_BIT_END: 269 decrease_duration(&ev, MCIR2_BIT_END); 270 271 if (data->count != MCIR2_HEADER_NBITS) { 272 data->state = STATE_HEADER_BIT_START; 273 goto again; 274 } 275 276 switch (mce_kbd_mode(data)) { 277 case MCIR2_MODE_KEYBOARD: 278 data->wanted_bits = MCIR2_KEYBOARD_NBITS; 279 break; 280 case MCIR2_MODE_MOUSE: 281 data->wanted_bits = MCIR2_MOUSE_NBITS; 282 break; 283 default: 284 dev_dbg(&dev->dev, "not keyboard or mouse data\n"); 285 goto out; 286 } 287 288 data->count = 0; 289 data->body = 0; 290 data->state = STATE_BODY_BIT_START; 291 goto again; 292 293 case STATE_BODY_BIT_START: 294 if (geq_margin(ev.duration, MCIR2_MAX_LEN, MCIR2_UNIT / 2)) 295 break; 296 297 data->body <<= 1; 298 if (ev.pulse) 299 data->body |= 1; 300 data->count++; 301 data->state = STATE_BODY_BIT_END; 302 return 0; 303 304 case STATE_BODY_BIT_END: 305 if (data->count == data->wanted_bits) 306 data->state = STATE_FINISHED; 307 else 308 data->state = STATE_BODY_BIT_START; 309 310 decrease_duration(&ev, MCIR2_BIT_END); 311 goto again; 312 313 case STATE_FINISHED: 314 if (ev.pulse) 315 break; 316 317 switch (data->wanted_bits) { 318 case MCIR2_KEYBOARD_NBITS: 319 scancode = data->body & 0xffffff; 320 dev_dbg(&dev->dev, "keyboard data 0x%08x\n", 321 data->body); 322 spin_lock(&data->keylock); 323 if (scancode) { 324 delay = usecs_to_jiffies(dev->timeout) + 325 msecs_to_jiffies(100); 326 mod_timer(&data->rx_timeout, jiffies + delay); 327 } else { 328 timer_delete(&data->rx_timeout); 329 } 330 /* Pass data to keyboard buffer parser */ 331 ir_mce_kbd_process_keyboard_data(dev, scancode); 332 spin_unlock(&data->keylock); 333 lsc.rc_proto = RC_PROTO_MCIR2_KBD; 334 break; 335 case MCIR2_MOUSE_NBITS: 336 scancode = data->body & 0x1fffff; 337 dev_dbg(&dev->dev, "mouse data 0x%06x\n", scancode); 338 /* Pass data to mouse buffer parser */ 339 ir_mce_kbd_process_mouse_data(dev, scancode); 340 lsc.rc_proto = RC_PROTO_MCIR2_MSE; 341 break; 342 default: 343 dev_dbg(&dev->dev, "not keyboard or mouse data\n"); 344 goto out; 345 } 346 347 lsc.scancode = scancode; 348 lirc_scancode_event(dev, &lsc); 349 data->state = STATE_INACTIVE; 350 input_event(dev->input_dev, EV_MSC, MSC_SCAN, scancode); 351 input_sync(dev->input_dev); 352 return 0; 353 } 354 355 out: 356 dev_dbg(&dev->dev, "failed at state %i (%uus %s)\n", 357 data->state, ev.duration, TO_STR(ev.pulse)); 358 data->state = STATE_INACTIVE; 359 return -EINVAL; 360 } 361 362 static int ir_mce_kbd_register(struct rc_dev *dev) 363 { 364 struct mce_kbd_dec *mce_kbd = &dev->raw->mce_kbd; 365 366 timer_setup(&mce_kbd->rx_timeout, mce_kbd_rx_timeout, 0); 367 spin_lock_init(&mce_kbd->keylock); 368 369 return 0; 370 } 371 372 static int ir_mce_kbd_unregister(struct rc_dev *dev) 373 { 374 struct mce_kbd_dec *mce_kbd = &dev->raw->mce_kbd; 375 376 timer_delete_sync(&mce_kbd->rx_timeout); 377 378 return 0; 379 } 380 381 static const struct ir_raw_timings_manchester ir_mce_kbd_timings = { 382 .leader_pulse = MCIR2_PREFIX_PULSE, 383 .invert = 1, 384 .clock = MCIR2_UNIT, 385 .trailer_space = MCIR2_UNIT * 10, 386 }; 387 388 /** 389 * ir_mce_kbd_encode() - Encode a scancode as a stream of raw events 390 * 391 * @protocol: protocol to encode 392 * @scancode: scancode to encode 393 * @events: array of raw ir events to write into 394 * @max: maximum size of @events 395 * 396 * Returns: The number of events written. 397 * -ENOBUFS if there isn't enough space in the array to fit the 398 * encoding. In this case all @max events will have been written. 399 */ 400 static int ir_mce_kbd_encode(enum rc_proto protocol, u32 scancode, 401 struct ir_raw_event *events, unsigned int max) 402 { 403 struct ir_raw_event *e = events; 404 int len, ret; 405 u64 raw; 406 407 if (protocol == RC_PROTO_MCIR2_KBD) { 408 raw = scancode | 409 ((u64)MCIR2_KEYBOARD_HEADER << MCIR2_KEYBOARD_NBITS); 410 len = MCIR2_KEYBOARD_NBITS + MCIR2_HEADER_NBITS; 411 } else { 412 raw = scancode | 413 ((u64)MCIR2_MOUSE_HEADER << MCIR2_MOUSE_NBITS); 414 len = MCIR2_MOUSE_NBITS + MCIR2_HEADER_NBITS; 415 } 416 417 ret = ir_raw_gen_manchester(&e, max, &ir_mce_kbd_timings, len, raw); 418 if (ret < 0) 419 return ret; 420 421 return e - events; 422 } 423 424 static struct ir_raw_handler mce_kbd_handler = { 425 .protocols = RC_PROTO_BIT_MCIR2_KBD | RC_PROTO_BIT_MCIR2_MSE, 426 .decode = ir_mce_kbd_decode, 427 .encode = ir_mce_kbd_encode, 428 .raw_register = ir_mce_kbd_register, 429 .raw_unregister = ir_mce_kbd_unregister, 430 .carrier = 36000, 431 .min_timeout = MCIR2_MAX_LEN + MCIR2_UNIT / 2, 432 }; 433 434 static int __init ir_mce_kbd_decode_init(void) 435 { 436 ir_raw_handler_register(&mce_kbd_handler); 437 438 printk(KERN_INFO "IR MCE Keyboard/mouse protocol handler initialized\n"); 439 return 0; 440 } 441 442 static void __exit ir_mce_kbd_decode_exit(void) 443 { 444 ir_raw_handler_unregister(&mce_kbd_handler); 445 } 446 447 module_init(ir_mce_kbd_decode_init); 448 module_exit(ir_mce_kbd_decode_exit); 449 450 MODULE_LICENSE("GPL"); 451 MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>"); 452 MODULE_DESCRIPTION("MCE Keyboard/mouse IR protocol decoder"); 453