drivers/media/rc/ir-mce_kbd-decoder.c

   1 /* ir-mce_kbd-decoder.c - A decoder for the RC6-ish keyboard/mouse IR protocol
   2  * used by the Microsoft Remote Keyboard for Windows Media Center Edition,
   3  * referred to by Microsoft's Windows Media Center remote specification docs
   4  * as "an internal protocol called MCIR-2".
   5  *
   6  * Copyright (C) 2011 by Jarod Wilson <jarod@redhat.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation version 2 of the License.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17 #include <linux/module.h>
  18
  19 #include "rc-core-priv.h"
  20
  21 /*
  22  * This decoder currently supports:
  23  * - MCIR-2 29-bit IR signals used for mouse movement and buttons
  24  * - MCIR-2 32-bit IR signals used for standard keyboard keys
  25  *
  26  * The media keys on the keyboard send RC-6 signals that are indistinguishable
  27  * from the keys of the same name on the stock MCE remote, and will be handled
  28  * by the standard RC-6 decoder, and be made available to the system via the
  29  * input device for the remote, rather than the keyboard/mouse one.
  30  */
  31
  32 #define MCIR2_UNIT              333333  /* ns */
  33 #define MCIR2_HEADER_NBITS      5
  34 #define MCIR2_MOUSE_NBITS       29
  35 #define MCIR2_KEYBOARD_NBITS    32
  36 #define MCIR2_PREFIX_PULSE      (8 * MCIR2_UNIT)
  37 #define MCIR2_PREFIX_SPACE      (1 * MCIR2_UNIT)
  38 #define MCIR2_MAX_LEN           (3 * MCIR2_UNIT)
  39 #define MCIR2_BIT_START         (1 * MCIR2_UNIT)
  40 #define MCIR2_BIT_END           (1 * MCIR2_UNIT)
  41 #define MCIR2_BIT_0             (1 * MCIR2_UNIT)
  42 #define MCIR2_BIT_SET           (2 * MCIR2_UNIT)
  43 #define MCIR2_MODE_MASK         0xf     /* for the header bits */
  44 #define MCIR2_KEYBOARD_HEADER   0x4
  45 #define MCIR2_MOUSE_HEADER      0x1
  46 #define MCIR2_MASK_KEYS_START   0xe0
  47
  48 enum mce_kbd_mode {
  49         MCIR2_MODE_KEYBOARD,
  50         MCIR2_MODE_MOUSE,
  51         MCIR2_MODE_UNKNOWN,
  52 };
  53
  54 enum mce_kbd_state {
  55         STATE_INACTIVE,
  56         STATE_HEADER_BIT_START,
  57         STATE_HEADER_BIT_END,
  58         STATE_BODY_BIT_START,
  59         STATE_BODY_BIT_END,
  60         STATE_FINISHED,
  61 };
  62
  63 static unsigned char kbd_keycodes[256] = {
  64         KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_A,
  65         KEY_B,          KEY_C,          KEY_D,          KEY_E,          KEY_F,
  66         KEY_G,          KEY_H,          KEY_I,          KEY_J,          KEY_K,
  67         KEY_L,          KEY_M,          KEY_N,          KEY_O,          KEY_P,
  68         KEY_Q,          KEY_R,          KEY_S,          KEY_T,          KEY_U,
  69         KEY_V,          KEY_W,          KEY_X,          KEY_Y,          KEY_Z,
  70         KEY_1,          KEY_2,          KEY_3,          KEY_4,          KEY_5,
  71         KEY_6,          KEY_7,          KEY_8,          KEY_9,          KEY_0,
  72         KEY_ENTER,      KEY_ESC,        KEY_BACKSPACE,  KEY_TAB,        KEY_SPACE,
  73         KEY_MINUS,      KEY_EQUAL,      KEY_LEFTBRACE,  KEY_RIGHTBRACE, KEY_BACKSLASH,
  74         KEY_BACKSLASH,  KEY_SEMICOLON,  KEY_APOSTROPHE, KEY_GRAVE,      KEY_COMMA,
  75         KEY_DOT,        KEY_SLASH,      KEY_CAPSLOCK,   KEY_F1,         KEY_F2,
  76         KEY_F3,         KEY_F4,         KEY_F5,         KEY_F6,         KEY_F7,
  77         KEY_F8,         KEY_F9,         KEY_F10,        KEY_F11,        KEY_F12,
  78         KEY_SYSRQ,      KEY_SCROLLLOCK, KEY_PAUSE,      KEY_INSERT,     KEY_HOME,
  79         KEY_PAGEUP,     KEY_DELETE,     KEY_END,        KEY_PAGEDOWN,   KEY_RIGHT,
  80         KEY_LEFT,       KEY_DOWN,       KEY_UP,         KEY_NUMLOCK,    KEY_KPSLASH,
  81         KEY_KPASTERISK, KEY_KPMINUS,    KEY_KPPLUS,     KEY_KPENTER,    KEY_KP1,
  82         KEY_KP2,        KEY_KP3,        KEY_KP4,        KEY_KP5,        KEY_KP6,
  83         KEY_KP7,        KEY_KP8,        KEY_KP9,        KEY_KP0,        KEY_KPDOT,
  84         KEY_102ND,      KEY_COMPOSE,    KEY_POWER,      KEY_KPEQUAL,    KEY_F13,
  85         KEY_F14,        KEY_F15,        KEY_F16,        KEY_F17,        KEY_F18,
  86         KEY_F19,        KEY_F20,        KEY_F21,        KEY_F22,        KEY_F23,
  87         KEY_F24,        KEY_OPEN,       KEY_HELP,       KEY_PROPS,      KEY_FRONT,
  88         KEY_STOP,       KEY_AGAIN,      KEY_UNDO,       KEY_CUT,        KEY_COPY,
  89         KEY_PASTE,      KEY_FIND,       KEY_MUTE,       KEY_VOLUMEUP,   KEY_VOLUMEDOWN,
  90         KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_KPCOMMA,    KEY_RESERVED,
  91         KEY_RO,         KEY_KATAKANAHIRAGANA, KEY_YEN,  KEY_HENKAN,     KEY_MUHENKAN,
  92         KEY_KPJPCOMMA,  KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_HANGUEL,
  93         KEY_HANJA,      KEY_KATAKANA,   KEY_HIRAGANA,   KEY_ZENKAKUHANKAKU, 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_RESERVED,
 101         KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,
 102         KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,
 103         KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,
 104         KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,
 105         KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,
 106         KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,
 107         KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,
 108         KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_LEFTCTRL,
 109         KEY_LEFTSHIFT,  KEY_LEFTALT,    KEY_LEFTMETA,   KEY_RIGHTCTRL,  KEY_RIGHTSHIFT,
 110         KEY_RIGHTALT,   KEY_RIGHTMETA,  KEY_PLAYPAUSE,  KEY_STOPCD,     KEY_PREVIOUSSONG,
 111         KEY_NEXTSONG,   KEY_EJECTCD,    KEY_VOLUMEUP,   KEY_VOLUMEDOWN, KEY_MUTE,
 112         KEY_WWW,        KEY_BACK,       KEY_FORWARD,    KEY_STOP,       KEY_FIND,
 113         KEY_SCROLLUP,   KEY_SCROLLDOWN, KEY_EDIT,       KEY_SLEEP,      KEY_COFFEE,
 114         KEY_REFRESH,    KEY_CALC,       KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,
 115         KEY_RESERVED
 116 };
 117
 118 static void mce_kbd_rx_timeout(struct timer_list *t)
 119 {
 120         struct ir_raw_event_ctrl *raw = from_timer(raw, t, mce_kbd.rx_timeout);
 121         unsigned char maskcode;
 122         unsigned long flags;
 123         int i;
 124
 125         dev_dbg(&raw->dev->dev, "timer callback clearing all keys\n");
 126
 127         spin_lock_irqsave(&raw->mce_kbd.keylock, flags);
 128
 129         if (time_is_before_eq_jiffies(raw->mce_kbd.rx_timeout.expires)) {
 130                 for (i = 0; i < 7; i++) {
 131                         maskcode = kbd_keycodes[MCIR2_MASK_KEYS_START + i];
 132                         input_report_key(raw->dev->input_dev, maskcode, 0);
 133                 }
 134
 135                 for (i = 0; i < MCIR2_MASK_KEYS_START; i++)
 136                         input_report_key(raw->dev->input_dev, kbd_keycodes[i],
 137                                          0);
 138
 139                 input_sync(raw->dev->input_dev);
 140         }
 141         spin_unlock_irqrestore(&raw->mce_kbd.keylock, flags);
 142 }
 143
 144 static enum mce_kbd_mode mce_kbd_mode(struct mce_kbd_dec *data)
 145 {
 146         switch (data->header & MCIR2_MODE_MASK) {
 147         case MCIR2_KEYBOARD_HEADER:
 148                 return MCIR2_MODE_KEYBOARD;
 149         case MCIR2_MOUSE_HEADER:
 150                 return MCIR2_MODE_MOUSE;
 151         default:
 152                 return MCIR2_MODE_UNKNOWN;
 153         }
 154 }
 155
 156 static void ir_mce_kbd_process_keyboard_data(struct rc_dev *dev, u32 scancode)
 157 {
 158         u8 keydata1  = (scancode >> 8) & 0xff;
 159         u8 keydata2  = (scancode >> 16) & 0xff;
 160         u8 shiftmask = scancode & 0xff;
 161         unsigned char maskcode;
 162         int i, keystate;
 163
 164         dev_dbg(&dev->dev, "keyboard: keydata2 = 0x%02x, keydata1 = 0x%02x, shiftmask = 0x%02x\n",
 165                 keydata2, keydata1, shiftmask);
 166
 167         for (i = 0; i < 7; i++) {
 168                 maskcode = kbd_keycodes[MCIR2_MASK_KEYS_START + i];
 169                 if (shiftmask & (1 << i))
 170                         keystate = 1;
 171                 else
 172                         keystate = 0;
 173                 input_report_key(dev->input_dev, maskcode, keystate);
 174         }
 175
 176         if (keydata1)
 177                 input_report_key(dev->input_dev, kbd_keycodes[keydata1], 1);
 178         if (keydata2)
 179                 input_report_key(dev->input_dev, kbd_keycodes[keydata2], 1);
 180
 181         if (!keydata1 && !keydata2) {
 182                 for (i = 0; i < MCIR2_MASK_KEYS_START; i++)
 183                         input_report_key(dev->input_dev, kbd_keycodes[i], 0);
 184         }
 185 }
 186
 187 static void ir_mce_kbd_process_mouse_data(struct rc_dev *dev, u32 scancode)
 188 {
 189         /* raw mouse coordinates */
 190         u8 xdata = (scancode >> 7) & 0x7f;
 191         u8 ydata = (scancode >> 14) & 0x7f;
 192         int x, y;
 193         /* mouse buttons */
 194         bool right = scancode & 0x40;
 195         bool left  = scancode & 0x20;
 196
 197         if (xdata & 0x40)
 198                 x = -((~xdata & 0x7f) + 1);
 199         else
 200                 x = xdata;
 201
 202         if (ydata & 0x40)
 203                 y = -((~ydata & 0x7f) + 1);
 204         else
 205                 y = ydata;
 206
 207         dev_dbg(&dev->dev, "mouse: x = %d, y = %d, btns = %s%s\n",
 208                 x, y, left ? "L" : "", right ? "R" : "");
 209
 210         input_report_rel(dev->input_dev, REL_X, x);
 211         input_report_rel(dev->input_dev, REL_Y, y);
 212
 213         input_report_key(dev->input_dev, BTN_LEFT, left);
 214         input_report_key(dev->input_dev, BTN_RIGHT, right);
 215 }
 216
 217 /**
 218  * ir_mce_kbd_decode() - Decode one mce_kbd pulse or space
 219  * @dev:        the struct rc_dev descriptor of the device
 220  * @ev:         the struct ir_raw_event descriptor of the pulse/space
 221  *
 222  * This function returns -EINVAL if the pulse violates the state machine
 223  */
 224 static int ir_mce_kbd_decode(struct rc_dev *dev, struct ir_raw_event ev)
 225 {
 226         struct mce_kbd_dec *data = &dev->raw->mce_kbd;
 227         u32 scancode;
 228         unsigned long delay;
 229         struct lirc_scancode lsc = {};
 230
 231         if (!is_timing_event(ev)) {
 232                 if (ev.reset)
 233                         data->state = STATE_INACTIVE;
 234                 return 0;
 235         }
 236
 237         if (!geq_margin(ev.duration, MCIR2_UNIT, MCIR2_UNIT / 2))
 238                 goto out;
 239
 240 again:
 241         dev_dbg(&dev->dev, "started at state %i (%uus %s)\n",
 242                 data->state, TO_US(ev.duration), TO_STR(ev.pulse));
 243
 244         if (!geq_margin(ev.duration, MCIR2_UNIT, MCIR2_UNIT / 2))
 245                 return 0;
 246
 247         switch (data->state) {
 248
 249         case STATE_INACTIVE:
 250                 if (!ev.pulse)
 251                         break;
 252
 253                 /* Note: larger margin on first pulse since each MCIR2_UNIT
 254                    is quite short and some hardware takes some time to
 255                    adjust to the signal */
 256                 if (!eq_margin(ev.duration, MCIR2_PREFIX_PULSE, MCIR2_UNIT))
 257                         break;
 258
 259                 data->state = STATE_HEADER_BIT_START;
 260                 data->count = 0;
 261                 data->header = 0;
 262                 return 0;
 263
 264         case STATE_HEADER_BIT_START:
 265                 if (geq_margin(ev.duration, MCIR2_MAX_LEN, MCIR2_UNIT / 2))
 266                         break;
 267
 268                 data->header <<= 1;
 269                 if (ev.pulse)
 270                         data->header |= 1;
 271                 data->count++;
 272                 data->state = STATE_HEADER_BIT_END;
 273                 return 0;
 274
 275         case STATE_HEADER_BIT_END:
 276                 decrease_duration(&ev, MCIR2_BIT_END);
 277
 278                 if (data->count != MCIR2_HEADER_NBITS) {
 279                         data->state = STATE_HEADER_BIT_START;
 280                         goto again;
 281                 }
 282
 283                 switch (mce_kbd_mode(data)) {
 284                 case MCIR2_MODE_KEYBOARD:
 285                         data->wanted_bits = MCIR2_KEYBOARD_NBITS;
 286                         break;
 287                 case MCIR2_MODE_MOUSE:
 288                         data->wanted_bits = MCIR2_MOUSE_NBITS;
 289                         break;
 290                 default:
 291                         dev_dbg(&dev->dev, "not keyboard or mouse data\n");
 292                         goto out;
 293                 }
 294
 295                 data->count = 0;
 296                 data->body = 0;
 297                 data->state = STATE_BODY_BIT_START;
 298                 goto again;
 299
 300         case STATE_BODY_BIT_START:
 301                 if (geq_margin(ev.duration, MCIR2_MAX_LEN, MCIR2_UNIT / 2))
 302                         break;
 303
 304                 data->body <<= 1;
 305                 if (ev.pulse)
 306                         data->body |= 1;
 307                 data->count++;
 308                 data->state = STATE_BODY_BIT_END;
 309                 return 0;
 310
 311         case STATE_BODY_BIT_END:
 312                 if (data->count == data->wanted_bits)
 313                         data->state = STATE_FINISHED;
 314                 else
 315                         data->state = STATE_BODY_BIT_START;
 316
 317                 decrease_duration(&ev, MCIR2_BIT_END);
 318                 goto again;
 319
 320         case STATE_FINISHED:
 321                 if (ev.pulse)
 322                         break;
 323
 324                 switch (data->wanted_bits) {
 325                 case MCIR2_KEYBOARD_NBITS:
 326                         scancode = data->body & 0xffffff;
 327                         dev_dbg(&dev->dev, "keyboard data 0x%08x\n",
 328                                 data->body);
 329                         spin_lock(&data->keylock);
 330                         if (scancode) {
 331                                 delay = nsecs_to_jiffies(dev->timeout) +
 332                                         msecs_to_jiffies(100);
 333                                 mod_timer(&data->rx_timeout, jiffies + delay);
 334                         } else {
 335                                 del_timer(&data->rx_timeout);
 336                         }
 337                         /* Pass data to keyboard buffer parser */
 338                         ir_mce_kbd_process_keyboard_data(dev, scancode);
 339                         spin_unlock(&data->keylock);
 340                         lsc.rc_proto = RC_PROTO_MCIR2_KBD;
 341                         break;
 342                 case MCIR2_MOUSE_NBITS:
 343                         scancode = data->body & 0x1fffff;
 344                         dev_dbg(&dev->dev, "mouse data 0x%06x\n", scancode);
 345                         /* Pass data to mouse buffer parser */
 346                         ir_mce_kbd_process_mouse_data(dev, scancode);
 347                         lsc.rc_proto = RC_PROTO_MCIR2_MSE;
 348                         break;
 349                 default:
 350                         dev_dbg(&dev->dev, "not keyboard or mouse data\n");
 351                         goto out;
 352                 }
 353
 354                 lsc.scancode = scancode;
 355                 ir_lirc_scancode_event(dev, &lsc);
 356                 data->state = STATE_INACTIVE;
 357                 input_event(dev->input_dev, EV_MSC, MSC_SCAN, scancode);
 358                 input_sync(dev->input_dev);
 359                 return 0;
 360         }
 361
 362 out:
 363         dev_dbg(&dev->dev, "failed at state %i (%uus %s)\n",
 364                 data->state, TO_US(ev.duration), TO_STR(ev.pulse));
 365         data->state = STATE_INACTIVE;
 366         return -EINVAL;
 367 }
 368
 369 static int ir_mce_kbd_register(struct rc_dev *dev)
 370 {
 371         struct mce_kbd_dec *mce_kbd = &dev->raw->mce_kbd;
 372
 373         timer_setup(&mce_kbd->rx_timeout, mce_kbd_rx_timeout, 0);
 374         spin_lock_init(&mce_kbd->keylock);
 375
 376         return 0;
 377 }
 378
 379 static int ir_mce_kbd_unregister(struct rc_dev *dev)
 380 {
 381         struct mce_kbd_dec *mce_kbd = &dev->raw->mce_kbd;
 382
 383         del_timer_sync(&mce_kbd->rx_timeout);
 384
 385         return 0;
 386 }
 387
 388 static const struct ir_raw_timings_manchester ir_mce_kbd_timings = {
 389         .leader_pulse   = MCIR2_PREFIX_PULSE,
 390         .invert         = 1,
 391         .clock          = MCIR2_UNIT,
 392         .trailer_space  = MCIR2_UNIT * 10,
 393 };
 394
 395 /**
 396  * ir_mce_kbd_encode() - Encode a scancode as a stream of raw events
 397  *
 398  * @protocol:   protocol to encode
 399  * @scancode:   scancode to encode
 400  * @events:     array of raw ir events to write into
 401  * @max:        maximum size of @events
 402  *
 403  * Returns:     The number of events written.
 404  *              -ENOBUFS if there isn't enough space in the array to fit the
 405  *              encoding. In this case all @max events will have been written.
 406  */
 407 static int ir_mce_kbd_encode(enum rc_proto protocol, u32 scancode,
 408                              struct ir_raw_event *events, unsigned int max)
 409 {
 410         struct ir_raw_event *e = events;
 411         int len, ret;
 412         u64 raw;
 413
 414         if (protocol == RC_PROTO_MCIR2_KBD) {
 415                 raw = scancode |
 416                       ((u64)MCIR2_KEYBOARD_HEADER << MCIR2_KEYBOARD_NBITS);
 417                 len = MCIR2_KEYBOARD_NBITS + MCIR2_HEADER_NBITS;
 418         } else {
 419                 raw = scancode |
 420                       ((u64)MCIR2_MOUSE_HEADER << MCIR2_MOUSE_NBITS);
 421                 len = MCIR2_MOUSE_NBITS + MCIR2_HEADER_NBITS;
 422         }
 423
 424         ret = ir_raw_gen_manchester(&e, max, &ir_mce_kbd_timings, len, raw);
 425         if (ret < 0)
 426                 return ret;
 427
 428         return e - events;
 429 }
 430
 431 static struct ir_raw_handler mce_kbd_handler = {
 432         .protocols      = RC_PROTO_BIT_MCIR2_KBD | RC_PROTO_BIT_MCIR2_MSE,
 433         .decode         = ir_mce_kbd_decode,
 434         .encode         = ir_mce_kbd_encode,
 435         .raw_register   = ir_mce_kbd_register,
 436         .raw_unregister = ir_mce_kbd_unregister,
 437         .carrier        = 36000,
 438         .min_timeout    = MCIR2_MAX_LEN + MCIR2_UNIT / 2,
 439 };
 440
 441 static int __init ir_mce_kbd_decode_init(void)
 442 {
 443         ir_raw_handler_register(&mce_kbd_handler);
 444
 445         printk(KERN_INFO "IR MCE Keyboard/mouse protocol handler initialized\n");
 446         return 0;
 447 }
 448
 449 static void __exit ir_mce_kbd_decode_exit(void)
 450 {
 451         ir_raw_handler_unregister(&mce_kbd_handler);
 452 }
 453
 454 module_init(ir_mce_kbd_decode_init);
 455 module_exit(ir_mce_kbd_decode_exit);
 456
 457 MODULE_LICENSE("GPL");
 458 MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>");
 459 MODULE_DESCRIPTION("MCE Keyboard/mouse IR protocol decoder");