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
  18 #include "rc-core-priv.h"
  19
  20 /*
  21  * This decoder currently supports:
  22  * - MCIR-2 29-bit IR signals used for mouse movement and buttons
  23  * - MCIR-2 32-bit IR signals used for standard keyboard keys
  24  *
  25  * The media keys on the keyboard send RC-6 signals that are inditinguishable
  26  * from the keys of the same name on the stock MCE remote, and will be handled
  27  * by the standard RC-6 decoder, and be made available to the system via the
  28  * input device for the remote, rather than the keyboard/mouse one.
  29  */
  30
  31 #define MCIR2_UNIT              333333  /* ns */
  32 #define MCIR2_HEADER_NBITS      5
  33 #define MCIR2_MOUSE_NBITS       29
  34 #define MCIR2_KEYBOARD_NBITS    32
  35 #define MCIR2_PREFIX_PULSE      (8 * MCIR2_UNIT)
  36 #define MCIR2_PREFIX_SPACE      (1 * MCIR2_UNIT)
  37 #define MCIR2_MAX_LEN           (3 * MCIR2_UNIT)
  38 #define MCIR2_BIT_START         (1 * MCIR2_UNIT)
  39 #define MCIR2_BIT_END           (1 * MCIR2_UNIT)
  40 #define MCIR2_BIT_0             (1 * MCIR2_UNIT)
  41 #define MCIR2_BIT_SET           (2 * MCIR2_UNIT)
  42 #define MCIR2_MODE_MASK         0xf     /* for the header bits */
  43 #define MCIR2_KEYBOARD_HEADER   0x4
  44 #define MCIR2_MOUSE_HEADER      0x1
  45 #define MCIR2_MASK_KEYS_START   0xe0
  46
  47 enum mce_kbd_mode {
  48         MCIR2_MODE_KEYBOARD,
  49         MCIR2_MODE_MOUSE,
  50         MCIR2_MODE_UNKNOWN,
  51 };
  52
  53 enum mce_kbd_state {
  54         STATE_INACTIVE,
  55         STATE_HEADER_BIT_START,
  56         STATE_HEADER_BIT_END,
  57         STATE_BODY_BIT_START,
  58         STATE_BODY_BIT_END,
  59         STATE_FINISHED,
  60 };
  61
  62 static unsigned char kbd_keycodes[256] = {
  63         KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_A,
  64         KEY_B,          KEY_C,          KEY_D,          KEY_E,          KEY_F,
  65         KEY_G,          KEY_H,          KEY_I,          KEY_J,          KEY_K,
  66         KEY_L,          KEY_M,          KEY_N,          KEY_O,          KEY_P,
  67         KEY_Q,          KEY_R,          KEY_S,          KEY_T,          KEY_U,
  68         KEY_V,          KEY_W,          KEY_X,          KEY_Y,          KEY_Z,
  69         KEY_1,          KEY_2,          KEY_3,          KEY_4,          KEY_5,
  70         KEY_6,          KEY_7,          KEY_8,          KEY_9,          KEY_0,
  71         KEY_ENTER,      KEY_ESC,        KEY_BACKSPACE,  KEY_TAB,        KEY_SPACE,
  72         KEY_MINUS,      KEY_EQUAL,      KEY_LEFTBRACE,  KEY_RIGHTBRACE, KEY_BACKSLASH,
  73         KEY_RESERVED,   KEY_SEMICOLON,  KEY_APOSTROPHE, KEY_GRAVE,      KEY_COMMA,
  74         KEY_DOT,        KEY_SLASH,      KEY_CAPSLOCK,   KEY_F1,         KEY_F2,
  75         KEY_F3,         KEY_F4,         KEY_F5,         KEY_F6,         KEY_F7,
  76         KEY_F8,         KEY_F9,         KEY_F10,        KEY_F11,        KEY_F12,
  77         KEY_SYSRQ,      KEY_SCROLLLOCK, KEY_PAUSE,      KEY_INSERT,     KEY_HOME,
  78         KEY_PAGEUP,     KEY_DELETE,     KEY_END,        KEY_PAGEDOWN,   KEY_RIGHT,
  79         KEY_LEFT,       KEY_DOWN,       KEY_UP,         KEY_NUMLOCK,    KEY_KPSLASH,
  80         KEY_KPASTERISK, KEY_KPMINUS,    KEY_KPPLUS,     KEY_KPENTER,    KEY_KP1,
  81         KEY_KP2,        KEY_KP3,        KEY_KP4,        KEY_KP5,        KEY_KP6,
  82         KEY_KP7,        KEY_KP8,        KEY_KP9,        KEY_KP0,        KEY_KPDOT,
  83         KEY_102ND,      KEY_COMPOSE,    KEY_POWER,      KEY_KPEQUAL,    KEY_F13,
  84         KEY_F14,        KEY_F15,        KEY_F16,        KEY_F17,        KEY_F18,
  85         KEY_F19,        KEY_F20,        KEY_F21,        KEY_F22,        KEY_F23,
  86         KEY_F24,        KEY_OPEN,       KEY_HELP,       KEY_PROPS,      KEY_FRONT,
  87         KEY_STOP,       KEY_AGAIN,      KEY_UNDO,       KEY_CUT,        KEY_COPY,
  88         KEY_PASTE,      KEY_FIND,       KEY_MUTE,       KEY_VOLUMEUP,   KEY_VOLUMEDOWN,
  89         KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_KPCOMMA,    KEY_RESERVED,
  90         KEY_RO,         KEY_KATAKANAHIRAGANA, KEY_YEN,  KEY_HENKAN,     KEY_MUHENKAN,
  91         KEY_KPJPCOMMA,  KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,   KEY_HANGUEL,
  92         KEY_HANJA,      KEY_KATAKANA,   KEY_HIRAGANA,   KEY_ZENKAKUHANKAKU, 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_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_LEFTCTRL,
 108         KEY_LEFTSHIFT,  KEY_LEFTALT,    KEY_LEFTMETA,   KEY_RIGHTCTRL,  KEY_RIGHTSHIFT,
 109         KEY_RIGHTALT,   KEY_RIGHTMETA,  KEY_PLAYPAUSE,  KEY_STOPCD,     KEY_PREVIOUSSONG,
 110         KEY_NEXTSONG,   KEY_EJECTCD,    KEY_VOLUMEUP,   KEY_VOLUMEDOWN, KEY_MUTE,
 111         KEY_WWW,        KEY_BACK,       KEY_FORWARD,    KEY_STOP,       KEY_FIND,
 112         KEY_SCROLLUP,   KEY_SCROLLDOWN, KEY_EDIT,       KEY_SLEEP,      KEY_COFFEE,
 113         KEY_REFRESH,    KEY_CALC,       KEY_RESERVED,   KEY_RESERVED,   KEY_RESERVED,
 114         KEY_RESERVED
 115 };
 116
 117 static void mce_kbd_rx_timeout(unsigned long data)
 118 {
 119         struct mce_kbd_dec *mce_kbd = (struct mce_kbd_dec *)data;
 120         int i;
 121         unsigned char maskcode;
 122
 123         IR_dprintk(2, "timer callback clearing all keys\n");
 124
 125         for (i = 0; i < 7; i++) {
 126                 maskcode = kbd_keycodes[MCIR2_MASK_KEYS_START + i];
 127                 input_report_key(mce_kbd->idev, maskcode, 0);
 128         }
 129
 130         for (i = 0; i < MCIR2_MASK_KEYS_START; i++)
 131                 input_report_key(mce_kbd->idev, kbd_keycodes[i], 0);
 132 }
 133
 134 static enum mce_kbd_mode mce_kbd_mode(struct mce_kbd_dec *data)
 135 {
 136         switch (data->header & MCIR2_MODE_MASK) {
 137         case MCIR2_KEYBOARD_HEADER:
 138                 return MCIR2_MODE_KEYBOARD;
 139         case MCIR2_MOUSE_HEADER:
 140                 return MCIR2_MODE_MOUSE;
 141         default:
 142                 return MCIR2_MODE_UNKNOWN;
 143         }
 144 }
 145
 146 static void ir_mce_kbd_process_keyboard_data(struct input_dev *idev,
 147                                              u32 scancode)
 148 {
 149         u8 keydata   = (scancode >> 8) & 0xff;
 150         u8 shiftmask = scancode & 0xff;
 151         unsigned char keycode, maskcode;
 152         int i, keystate;
 153
 154         IR_dprintk(1, "keyboard: keydata = 0x%02x, shiftmask = 0x%02x\n",
 155                    keydata, shiftmask);
 156
 157         for (i = 0; i < 7; i++) {
 158                 maskcode = kbd_keycodes[MCIR2_MASK_KEYS_START + i];
 159                 if (shiftmask & (1 << i))
 160                         keystate = 1;
 161                 else
 162                         keystate = 0;
 163                 input_report_key(idev, maskcode, keystate);
 164         }
 165
 166         if (keydata) {
 167                 keycode = kbd_keycodes[keydata];
 168                 input_report_key(idev, keycode, 1);
 169         } else {
 170                 for (i = 0; i < MCIR2_MASK_KEYS_START; i++)
 171                         input_report_key(idev, kbd_keycodes[i], 0);
 172         }
 173 }
 174
 175 static void ir_mce_kbd_process_mouse_data(struct input_dev *idev, u32 scancode)
 176 {
 177         /* raw mouse coordinates */
 178         u8 xdata = (scancode >> 7) & 0x7f;
 179         u8 ydata = (scancode >> 14) & 0x7f;
 180         int x, y;
 181         /* mouse buttons */
 182         bool right = scancode & 0x40;
 183         bool left  = scancode & 0x20;
 184
 185         if (xdata & 0x40)
 186                 x = -((~xdata & 0x7f) + 1);
 187         else
 188                 x = xdata;
 189
 190         if (ydata & 0x40)
 191                 y = -((~ydata & 0x7f) + 1);
 192         else
 193                 y = ydata;
 194
 195         IR_dprintk(1, "mouse: x = %d, y = %d, btns = %s%s\n",
 196                    x, y, left ? "L" : "", right ? "R" : "");
 197
 198         input_report_rel(idev, REL_X, x);
 199         input_report_rel(idev, REL_Y, y);
 200
 201         input_report_key(idev, BTN_LEFT, left);
 202         input_report_key(idev, BTN_RIGHT, right);
 203 }
 204
 205 /**
 206  * ir_mce_kbd_decode() - Decode one mce_kbd pulse or space
 207  * @dev:        the struct rc_dev descriptor of the device
 208  * @ev:         the struct ir_raw_event descriptor of the pulse/space
 209  *
 210  * This function returns -EINVAL if the pulse violates the state machine
 211  */
 212 static int ir_mce_kbd_decode(struct rc_dev *dev, struct ir_raw_event ev)
 213 {
 214         struct mce_kbd_dec *data = &dev->raw->mce_kbd;
 215         u32 scancode;
 216         unsigned long delay;
 217
 218         if (!(dev->raw->enabled_protocols & RC_TYPE_MCE_KBD))
 219                 return 0;
 220
 221         if (!is_timing_event(ev)) {
 222                 if (ev.reset)
 223                         data->state = STATE_INACTIVE;
 224                 return 0;
 225         }
 226
 227         if (!geq_margin(ev.duration, MCIR2_UNIT, MCIR2_UNIT / 2))
 228                 goto out;
 229
 230 again:
 231         IR_dprintk(2, "started at state %i (%uus %s)\n",
 232                    data->state, TO_US(ev.duration), TO_STR(ev.pulse));
 233
 234         if (!geq_margin(ev.duration, MCIR2_UNIT, MCIR2_UNIT / 2))
 235                 return 0;
 236
 237         switch (data->state) {
 238
 239         case STATE_INACTIVE:
 240                 if (!ev.pulse)
 241                         break;
 242
 243                 /* Note: larger margin on first pulse since each MCIR2_UNIT
 244                    is quite short and some hardware takes some time to
 245                    adjust to the signal */
 246                 if (!eq_margin(ev.duration, MCIR2_PREFIX_PULSE, MCIR2_UNIT))
 247                         break;
 248
 249                 data->state = STATE_HEADER_BIT_START;
 250                 data->count = 0;
 251                 data->header = 0;
 252                 return 0;
 253
 254         case STATE_HEADER_BIT_START:
 255                 if (geq_margin(ev.duration, MCIR2_MAX_LEN, MCIR2_UNIT / 2))
 256                         break;
 257
 258                 data->header <<= 1;
 259                 if (ev.pulse)
 260                         data->header |= 1;
 261                 data->count++;
 262                 data->state = STATE_HEADER_BIT_END;
 263                 return 0;
 264
 265         case STATE_HEADER_BIT_END:
 266                 if (!is_transition(&ev, &dev->raw->prev_ev))
 267                         break;
 268
 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                         IR_dprintk(1, "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 (!is_transition(&ev, &dev->raw->prev_ev))
 306                         break;
 307
 308                 if (data->count == data->wanted_bits)
 309                         data->state = STATE_FINISHED;
 310                 else
 311                         data->state = STATE_BODY_BIT_START;
 312
 313                 decrease_duration(&ev, MCIR2_BIT_END);
 314                 goto again;
 315
 316         case STATE_FINISHED:
 317                 if (ev.pulse)
 318                         break;
 319
 320                 switch (data->wanted_bits) {
 321                 case MCIR2_KEYBOARD_NBITS:
 322                         scancode = data->body & 0xffff;
 323                         IR_dprintk(1, "keyboard data 0x%08x\n", data->body);
 324                         if (dev->timeout)
 325                                 delay = usecs_to_jiffies(dev->timeout / 1000);
 326                         else
 327                                 delay = msecs_to_jiffies(100);
 328                         mod_timer(&data->rx_timeout, jiffies + delay);
 329                         /* Pass data to keyboard buffer parser */
 330                         ir_mce_kbd_process_keyboard_data(data->idev, scancode);
 331                         break;
 332                 case MCIR2_MOUSE_NBITS:
 333                         scancode = data->body & 0x1fffff;
 334                         IR_dprintk(1, "mouse data 0x%06x\n", scancode);
 335                         /* Pass data to mouse buffer parser */
 336                         ir_mce_kbd_process_mouse_data(data->idev, scancode);
 337                         break;
 338                 default:
 339                         IR_dprintk(1, "not keyboard or mouse data\n");
 340                         goto out;
 341                 }
 342
 343                 data->state = STATE_INACTIVE;
 344                 input_sync(data->idev);
 345                 return 0;
 346         }
 347
 348 out:
 349         IR_dprintk(1, "failed at state %i (%uus %s)\n",
 350                    data->state, TO_US(ev.duration), TO_STR(ev.pulse));
 351         data->state = STATE_INACTIVE;
 352         input_sync(data->idev);
 353         return -EINVAL;
 354 }
 355
 356 static int ir_mce_kbd_register(struct rc_dev *dev)
 357 {
 358         struct mce_kbd_dec *mce_kbd = &dev->raw->mce_kbd;
 359         struct input_dev *idev;
 360         int i, ret;
 361
 362         idev = input_allocate_device();
 363         if (!idev)
 364                 return -ENOMEM;
 365
 366         snprintf(mce_kbd->name, sizeof(mce_kbd->name),
 367                  "MCE IR Keyboard/Mouse (%s)", dev->driver_name);
 368         strlcat(mce_kbd->phys, "/input0", sizeof(mce_kbd->phys));
 369
 370         idev->name = mce_kbd->name;
 371         idev->phys = mce_kbd->phys;
 372
 373         /* Keyboard bits */
 374         set_bit(EV_KEY, idev->evbit);
 375         set_bit(EV_REP, idev->evbit);
 376         for (i = 0; i < sizeof(kbd_keycodes); i++)
 377                 set_bit(kbd_keycodes[i], idev->keybit);
 378
 379         /* Mouse bits */
 380         set_bit(EV_REL, idev->evbit);
 381         set_bit(REL_X, idev->relbit);
 382         set_bit(REL_Y, idev->relbit);
 383         set_bit(BTN_LEFT, idev->keybit);
 384         set_bit(BTN_RIGHT, idev->keybit);
 385
 386         /* Report scancodes too */
 387         set_bit(EV_MSC, idev->evbit);
 388         set_bit(MSC_SCAN, idev->mscbit);
 389
 390         setup_timer(&mce_kbd->rx_timeout, mce_kbd_rx_timeout,
 391                     (unsigned long)mce_kbd);
 392
 393         input_set_drvdata(idev, mce_kbd);
 394
 395 #if 0
 396         /* Adding this reference means two input devices are associated with
 397          * this rc-core device, which ir-keytable doesn't cope with yet */
 398         idev->dev.parent = &dev->dev;
 399 #endif
 400
 401         ret = input_register_device(idev);
 402         if (ret < 0) {
 403                 input_free_device(idev);
 404                 return -EIO;
 405         }
 406
 407         mce_kbd->idev = idev;
 408
 409         return 0;
 410 }
 411
 412 static int ir_mce_kbd_unregister(struct rc_dev *dev)
 413 {
 414         struct mce_kbd_dec *mce_kbd = &dev->raw->mce_kbd;
 415         struct input_dev *idev = mce_kbd->idev;
 416
 417         del_timer_sync(&mce_kbd->rx_timeout);
 418         input_unregister_device(idev);
 419
 420         return 0;
 421 }
 422
 423 static struct ir_raw_handler mce_kbd_handler = {
 424         .protocols      = RC_TYPE_MCE_KBD,
 425         .decode         = ir_mce_kbd_decode,
 426         .raw_register   = ir_mce_kbd_register,
 427         .raw_unregister = ir_mce_kbd_unregister,
 428 };
 429
 430 static int __init ir_mce_kbd_decode_init(void)
 431 {
 432         ir_raw_handler_register(&mce_kbd_handler);
 433
 434         printk(KERN_INFO "IR MCE Keyboard/mouse protocol handler initialized\n");
 435         return 0;
 436 }
 437
 438 static void __exit ir_mce_kbd_decode_exit(void)
 439 {
 440         ir_raw_handler_unregister(&mce_kbd_handler);
 441 }
 442
 443 module_init(ir_mce_kbd_decode_init);
 444 module_exit(ir_mce_kbd_decode_exit);
 445
 446 MODULE_LICENSE("GPL");
 447 MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>");
 448 MODULE_DESCRIPTION("MCE Keyboard/mouse IR protocol decoder");