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 333333 /* ns */ 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 = from_timer(raw, t, mce_kbd.rx_timeout); 113 unsigned char maskcode; 114 unsigned long flags; 115 int i; 116 117 dev_dbg(&raw->dev->dev, "timer callback clearing all keys\n"); 118 119 spin_lock_irqsave(&raw->mce_kbd.keylock, flags); 120 121 if (time_is_before_eq_jiffies(raw->mce_kbd.rx_timeout.expires)) { 122 for (i = 0; i < 7; i++) { 123 maskcode = kbd_keycodes[MCIR2_MASK_KEYS_START + i]; 124 input_report_key(raw->dev->input_dev, maskcode, 0); 125 } 126 127 for (i = 0; i < MCIR2_MASK_KEYS_START; i++) 128 input_report_key(raw->dev->input_dev, kbd_keycodes[i], 129 0); 130 131 input_sync(raw->dev->input_dev); 132 } 133 spin_unlock_irqrestore(&raw->mce_kbd.keylock, flags); 134 } 135 136 static enum mce_kbd_mode mce_kbd_mode(struct mce_kbd_dec *data) 137 { 138 switch (data->header & MCIR2_MODE_MASK) { 139 case MCIR2_KEYBOARD_HEADER: 140 return MCIR2_MODE_KEYBOARD; 141 case MCIR2_MOUSE_HEADER: 142 return MCIR2_MODE_MOUSE; 143 default: 144 return MCIR2_MODE_UNKNOWN; 145 } 146 } 147 148 static void ir_mce_kbd_process_keyboard_data(struct rc_dev *dev, u32 scancode) 149 { 150 u8 keydata1 = (scancode >> 8) & 0xff; 151 u8 keydata2 = (scancode >> 16) & 0xff; 152 u8 shiftmask = scancode & 0xff; 153 unsigned char maskcode; 154 int i, keystate; 155 156 dev_dbg(&dev->dev, "keyboard: keydata2 = 0x%02x, keydata1 = 0x%02x, shiftmask = 0x%02x\n", 157 keydata2, keydata1, shiftmask); 158 159 for (i = 0; i < 7; i++) { 160 maskcode = kbd_keycodes[MCIR2_MASK_KEYS_START + i]; 161 if (shiftmask & (1 << i)) 162 keystate = 1; 163 else 164 keystate = 0; 165 input_report_key(dev->input_dev, maskcode, keystate); 166 } 167 168 if (keydata1) 169 input_report_key(dev->input_dev, kbd_keycodes[keydata1], 1); 170 if (keydata2) 171 input_report_key(dev->input_dev, kbd_keycodes[keydata2], 1); 172 173 if (!keydata1 && !keydata2) { 174 for (i = 0; i < MCIR2_MASK_KEYS_START; i++) 175 input_report_key(dev->input_dev, kbd_keycodes[i], 0); 176 } 177 } 178 179 static void ir_mce_kbd_process_mouse_data(struct rc_dev *dev, u32 scancode) 180 { 181 /* raw mouse coordinates */ 182 u8 xdata = (scancode >> 7) & 0x7f; 183 u8 ydata = (scancode >> 14) & 0x7f; 184 int x, y; 185 /* mouse buttons */ 186 bool right = scancode & 0x40; 187 bool left = scancode & 0x20; 188 189 if (xdata & 0x40) 190 x = -((~xdata & 0x7f) + 1); 191 else 192 x = xdata; 193 194 if (ydata & 0x40) 195 y = -((~ydata & 0x7f) + 1); 196 else 197 y = ydata; 198 199 dev_dbg(&dev->dev, "mouse: x = %d, y = %d, btns = %s%s\n", 200 x, y, left ? "L" : "", right ? "R" : ""); 201 202 input_report_rel(dev->input_dev, REL_X, x); 203 input_report_rel(dev->input_dev, REL_Y, y); 204 205 input_report_key(dev->input_dev, BTN_LEFT, left); 206 input_report_key(dev->input_dev, BTN_RIGHT, right); 207 } 208 209 /** 210 * ir_mce_kbd_decode() - Decode one mce_kbd pulse or space 211 * @dev: the struct rc_dev descriptor of the device 212 * @ev: the struct ir_raw_event descriptor of the pulse/space 213 * 214 * This function returns -EINVAL if the pulse violates the state machine 215 */ 216 static int ir_mce_kbd_decode(struct rc_dev *dev, struct ir_raw_event ev) 217 { 218 struct mce_kbd_dec *data = &dev->raw->mce_kbd; 219 u32 scancode; 220 unsigned long delay; 221 struct lirc_scancode lsc = {}; 222 223 if (!is_timing_event(ev)) { 224 if (ev.reset) 225 data->state = STATE_INACTIVE; 226 return 0; 227 } 228 229 if (!geq_margin(ev.duration, MCIR2_UNIT, MCIR2_UNIT / 2)) 230 goto out; 231 232 again: 233 dev_dbg(&dev->dev, "started at state %i (%uus %s)\n", 234 data->state, TO_US(ev.duration), TO_STR(ev.pulse)); 235 236 if (!geq_margin(ev.duration, MCIR2_UNIT, MCIR2_UNIT / 2)) 237 return 0; 238 239 switch (data->state) { 240 241 case STATE_INACTIVE: 242 if (!ev.pulse) 243 break; 244 245 /* Note: larger margin on first pulse since each MCIR2_UNIT 246 is quite short and some hardware takes some time to 247 adjust to the signal */ 248 if (!eq_margin(ev.duration, MCIR2_PREFIX_PULSE, MCIR2_UNIT)) 249 break; 250 251 data->state = STATE_HEADER_BIT_START; 252 data->count = 0; 253 data->header = 0; 254 return 0; 255 256 case STATE_HEADER_BIT_START: 257 if (geq_margin(ev.duration, MCIR2_MAX_LEN, MCIR2_UNIT / 2)) 258 break; 259 260 data->header <<= 1; 261 if (ev.pulse) 262 data->header |= 1; 263 data->count++; 264 data->state = STATE_HEADER_BIT_END; 265 return 0; 266 267 case STATE_HEADER_BIT_END: 268 decrease_duration(&ev, MCIR2_BIT_END); 269 270 if (data->count != MCIR2_HEADER_NBITS) { 271 data->state = STATE_HEADER_BIT_START; 272 goto again; 273 } 274 275 switch (mce_kbd_mode(data)) { 276 case MCIR2_MODE_KEYBOARD: 277 data->wanted_bits = MCIR2_KEYBOARD_NBITS; 278 break; 279 case MCIR2_MODE_MOUSE: 280 data->wanted_bits = MCIR2_MOUSE_NBITS; 281 break; 282 default: 283 dev_dbg(&dev->dev, "not keyboard or mouse data\n"); 284 goto out; 285 } 286 287 data->count = 0; 288 data->body = 0; 289 data->state = STATE_BODY_BIT_START; 290 goto again; 291 292 case STATE_BODY_BIT_START: 293 if (geq_margin(ev.duration, MCIR2_MAX_LEN, MCIR2_UNIT / 2)) 294 break; 295 296 data->body <<= 1; 297 if (ev.pulse) 298 data->body |= 1; 299 data->count++; 300 data->state = STATE_BODY_BIT_END; 301 return 0; 302 303 case STATE_BODY_BIT_END: 304 if (data->count == data->wanted_bits) 305 data->state = STATE_FINISHED; 306 else 307 data->state = STATE_BODY_BIT_START; 308 309 decrease_duration(&ev, MCIR2_BIT_END); 310 goto again; 311 312 case STATE_FINISHED: 313 if (ev.pulse) 314 break; 315 316 switch (data->wanted_bits) { 317 case MCIR2_KEYBOARD_NBITS: 318 scancode = data->body & 0xffffff; 319 dev_dbg(&dev->dev, "keyboard data 0x%08x\n", 320 data->body); 321 spin_lock(&data->keylock); 322 if (scancode) { 323 delay = nsecs_to_jiffies(dev->timeout) + 324 msecs_to_jiffies(100); 325 mod_timer(&data->rx_timeout, jiffies + delay); 326 } else { 327 del_timer(&data->rx_timeout); 328 } 329 /* Pass data to keyboard buffer parser */ 330 ir_mce_kbd_process_keyboard_data(dev, scancode); 331 spin_unlock(&data->keylock); 332 lsc.rc_proto = RC_PROTO_MCIR2_KBD; 333 break; 334 case MCIR2_MOUSE_NBITS: 335 scancode = data->body & 0x1fffff; 336 dev_dbg(&dev->dev, "mouse data 0x%06x\n", scancode); 337 /* Pass data to mouse buffer parser */ 338 ir_mce_kbd_process_mouse_data(dev, scancode); 339 lsc.rc_proto = RC_PROTO_MCIR2_MSE; 340 break; 341 default: 342 dev_dbg(&dev->dev, "not keyboard or mouse data\n"); 343 goto out; 344 } 345 346 lsc.scancode = scancode; 347 ir_lirc_scancode_event(dev, &lsc); 348 data->state = STATE_INACTIVE; 349 input_event(dev->input_dev, EV_MSC, MSC_SCAN, scancode); 350 input_sync(dev->input_dev); 351 return 0; 352 } 353 354 out: 355 dev_dbg(&dev->dev, "failed at state %i (%uus %s)\n", 356 data->state, TO_US(ev.duration), TO_STR(ev.pulse)); 357 data->state = STATE_INACTIVE; 358 return -EINVAL; 359 } 360 361 static int ir_mce_kbd_register(struct rc_dev *dev) 362 { 363 struct mce_kbd_dec *mce_kbd = &dev->raw->mce_kbd; 364 365 timer_setup(&mce_kbd->rx_timeout, mce_kbd_rx_timeout, 0); 366 spin_lock_init(&mce_kbd->keylock); 367 368 return 0; 369 } 370 371 static int ir_mce_kbd_unregister(struct rc_dev *dev) 372 { 373 struct mce_kbd_dec *mce_kbd = &dev->raw->mce_kbd; 374 375 del_timer_sync(&mce_kbd->rx_timeout); 376 377 return 0; 378 } 379 380 static const struct ir_raw_timings_manchester ir_mce_kbd_timings = { 381 .leader_pulse = MCIR2_PREFIX_PULSE, 382 .invert = 1, 383 .clock = MCIR2_UNIT, 384 .trailer_space = MCIR2_UNIT * 10, 385 }; 386 387 /** 388 * ir_mce_kbd_encode() - Encode a scancode as a stream of raw events 389 * 390 * @protocol: protocol to encode 391 * @scancode: scancode to encode 392 * @events: array of raw ir events to write into 393 * @max: maximum size of @events 394 * 395 * Returns: The number of events written. 396 * -ENOBUFS if there isn't enough space in the array to fit the 397 * encoding. In this case all @max events will have been written. 398 */ 399 static int ir_mce_kbd_encode(enum rc_proto protocol, u32 scancode, 400 struct ir_raw_event *events, unsigned int max) 401 { 402 struct ir_raw_event *e = events; 403 int len, ret; 404 u64 raw; 405 406 if (protocol == RC_PROTO_MCIR2_KBD) { 407 raw = scancode | 408 ((u64)MCIR2_KEYBOARD_HEADER << MCIR2_KEYBOARD_NBITS); 409 len = MCIR2_KEYBOARD_NBITS + MCIR2_HEADER_NBITS; 410 } else { 411 raw = scancode | 412 ((u64)MCIR2_MOUSE_HEADER << MCIR2_MOUSE_NBITS); 413 len = MCIR2_MOUSE_NBITS + MCIR2_HEADER_NBITS; 414 } 415 416 ret = ir_raw_gen_manchester(&e, max, &ir_mce_kbd_timings, len, raw); 417 if (ret < 0) 418 return ret; 419 420 return e - events; 421 } 422 423 static struct ir_raw_handler mce_kbd_handler = { 424 .protocols = RC_PROTO_BIT_MCIR2_KBD | RC_PROTO_BIT_MCIR2_MSE, 425 .decode = ir_mce_kbd_decode, 426 .encode = ir_mce_kbd_encode, 427 .raw_register = ir_mce_kbd_register, 428 .raw_unregister = ir_mce_kbd_unregister, 429 .carrier = 36000, 430 .min_timeout = MCIR2_MAX_LEN + MCIR2_UNIT / 2, 431 }; 432 433 static int __init ir_mce_kbd_decode_init(void) 434 { 435 ir_raw_handler_register(&mce_kbd_handler); 436 437 printk(KERN_INFO "IR MCE Keyboard/mouse protocol handler initialized\n"); 438 return 0; 439 } 440 441 static void __exit ir_mce_kbd_decode_exit(void) 442 { 443 ir_raw_handler_unregister(&mce_kbd_handler); 444 } 445 446 module_init(ir_mce_kbd_decode_init); 447 module_exit(ir_mce_kbd_decode_exit); 448 449 MODULE_LICENSE("GPL"); 450 MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>"); 451 MODULE_DESCRIPTION("MCE Keyboard/mouse IR protocol decoder"); 452