linux/drivers/media/rc/ir-mce_kbd-decoder.c
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   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 inditinguishable
  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
  48enum mce_kbd_mode {
  49        MCIR2_MODE_KEYBOARD,
  50        MCIR2_MODE_MOUSE,
  51        MCIR2_MODE_UNKNOWN,
  52};
  53
  54enum 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
  63static 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_RESERVED,   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
 118static void mce_kbd_rx_timeout(unsigned long data)
 119{
 120        struct mce_kbd_dec *mce_kbd = (struct mce_kbd_dec *)data;
 121        int i;
 122        unsigned char maskcode;
 123
 124        IR_dprintk(2, "timer callback clearing all keys\n");
 125
 126        for (i = 0; i < 7; i++) {
 127                maskcode = kbd_keycodes[MCIR2_MASK_KEYS_START + i];
 128                input_report_key(mce_kbd->idev, maskcode, 0);
 129        }
 130
 131        for (i = 0; i < MCIR2_MASK_KEYS_START; i++)
 132                input_report_key(mce_kbd->idev, kbd_keycodes[i], 0);
 133}
 134
 135static enum mce_kbd_mode mce_kbd_mode(struct mce_kbd_dec *data)
 136{
 137        switch (data->header & MCIR2_MODE_MASK) {
 138        case MCIR2_KEYBOARD_HEADER:
 139                return MCIR2_MODE_KEYBOARD;
 140        case MCIR2_MOUSE_HEADER:
 141                return MCIR2_MODE_MOUSE;
 142        default:
 143                return MCIR2_MODE_UNKNOWN;
 144        }
 145}
 146
 147static void ir_mce_kbd_process_keyboard_data(struct input_dev *idev,
 148                                             u32 scancode)
 149{
 150        u8 keydata   = (scancode >> 8) & 0xff;
 151        u8 shiftmask = scancode & 0xff;
 152        unsigned char keycode, maskcode;
 153        int i, keystate;
 154
 155        IR_dprintk(1, "keyboard: keydata = 0x%02x, shiftmask = 0x%02x\n",
 156                   keydata, shiftmask);
 157
 158        for (i = 0; i < 7; i++) {
 159                maskcode = kbd_keycodes[MCIR2_MASK_KEYS_START + i];
 160                if (shiftmask & (1 << i))
 161                        keystate = 1;
 162                else
 163                        keystate = 0;
 164                input_report_key(idev, maskcode, keystate);
 165        }
 166
 167        if (keydata) {
 168                keycode = kbd_keycodes[keydata];
 169                input_report_key(idev, keycode, 1);
 170        } else {
 171                for (i = 0; i < MCIR2_MASK_KEYS_START; i++)
 172                        input_report_key(idev, kbd_keycodes[i], 0);
 173        }
 174}
 175
 176static void ir_mce_kbd_process_mouse_data(struct input_dev *idev, u32 scancode)
 177{
 178        /* raw mouse coordinates */
 179        u8 xdata = (scancode >> 7) & 0x7f;
 180        u8 ydata = (scancode >> 14) & 0x7f;
 181        int x, y;
 182        /* mouse buttons */
 183        bool right = scancode & 0x40;
 184        bool left  = scancode & 0x20;
 185
 186        if (xdata & 0x40)
 187                x = -((~xdata & 0x7f) + 1);
 188        else
 189                x = xdata;
 190
 191        if (ydata & 0x40)
 192                y = -((~ydata & 0x7f) + 1);
 193        else
 194                y = ydata;
 195
 196        IR_dprintk(1, "mouse: x = %d, y = %d, btns = %s%s\n",
 197                   x, y, left ? "L" : "", right ? "R" : "");
 198
 199        input_report_rel(idev, REL_X, x);
 200        input_report_rel(idev, REL_Y, y);
 201
 202        input_report_key(idev, BTN_LEFT, left);
 203        input_report_key(idev, BTN_RIGHT, right);
 204}
 205
 206/**
 207 * ir_mce_kbd_decode() - Decode one mce_kbd pulse or space
 208 * @dev:        the struct rc_dev descriptor of the device
 209 * @ev:         the struct ir_raw_event descriptor of the pulse/space
 210 *
 211 * This function returns -EINVAL if the pulse violates the state machine
 212 */
 213static int ir_mce_kbd_decode(struct rc_dev *dev, struct ir_raw_event ev)
 214{
 215        struct mce_kbd_dec *data = &dev->raw->mce_kbd;
 216        u32 scancode;
 217        unsigned long delay;
 218
 219        if (!(dev->raw->enabled_protocols & RC_TYPE_MCE_KBD))
 220                return 0;
 221
 222        if (!is_timing_event(ev)) {
 223                if (ev.reset)
 224                        data->state = STATE_INACTIVE;
 225                return 0;
 226        }
 227
 228        if (!geq_margin(ev.duration, MCIR2_UNIT, MCIR2_UNIT / 2))
 229                goto out;
 230
 231again:
 232        IR_dprintk(2, "started at state %i (%uus %s)\n",
 233                   data->state, TO_US(ev.duration), TO_STR(ev.pulse));
 234
 235        if (!geq_margin(ev.duration, MCIR2_UNIT, MCIR2_UNIT / 2))
 236                return 0;
 237
 238        switch (data->state) {
 239
 240        case STATE_INACTIVE:
 241                if (!ev.pulse)
 242                        break;
 243
 244                /* Note: larger margin on first pulse since each MCIR2_UNIT
 245                   is quite short and some hardware takes some time to
 246                   adjust to the signal */
 247                if (!eq_margin(ev.duration, MCIR2_PREFIX_PULSE, MCIR2_UNIT))
 248                        break;
 249
 250                data->state = STATE_HEADER_BIT_START;
 251                data->count = 0;
 252                data->header = 0;
 253                return 0;
 254
 255        case STATE_HEADER_BIT_START:
 256                if (geq_margin(ev.duration, MCIR2_MAX_LEN, MCIR2_UNIT / 2))
 257                        break;
 258
 259                data->header <<= 1;
 260                if (ev.pulse)
 261                        data->header |= 1;
 262                data->count++;
 263                data->state = STATE_HEADER_BIT_END;
 264                return 0;
 265
 266        case STATE_HEADER_BIT_END:
 267                if (!is_transition(&ev, &dev->raw->prev_ev))
 268                        break;
 269
 270                decrease_duration(&ev, MCIR2_BIT_END);
 271
 272                if (data->count != MCIR2_HEADER_NBITS) {
 273                        data->state = STATE_HEADER_BIT_START;
 274                        goto again;
 275                }
 276
 277                switch (mce_kbd_mode(data)) {
 278                case MCIR2_MODE_KEYBOARD:
 279                        data->wanted_bits = MCIR2_KEYBOARD_NBITS;
 280                        break;
 281                case MCIR2_MODE_MOUSE:
 282                        data->wanted_bits = MCIR2_MOUSE_NBITS;
 283                        break;
 284                default:
 285                        IR_dprintk(1, "not keyboard or mouse data\n");
 286                        goto out;
 287                }
 288
 289                data->count = 0;
 290                data->body = 0;
 291                data->state = STATE_BODY_BIT_START;
 292                goto again;
 293
 294        case STATE_BODY_BIT_START:
 295                if (geq_margin(ev.duration, MCIR2_MAX_LEN, MCIR2_UNIT / 2))
 296                        break;
 297
 298                data->body <<= 1;
 299                if (ev.pulse)
 300                        data->body |= 1;
 301                data->count++;
 302                data->state = STATE_BODY_BIT_END;
 303                return 0;
 304
 305        case STATE_BODY_BIT_END:
 306                if (!is_transition(&ev, &dev->raw->prev_ev))
 307                        break;
 308
 309                if (data->count == data->wanted_bits)
 310                        data->state = STATE_FINISHED;
 311                else
 312                        data->state = STATE_BODY_BIT_START;
 313
 314                decrease_duration(&ev, MCIR2_BIT_END);
 315                goto again;
 316
 317        case STATE_FINISHED:
 318                if (ev.pulse)
 319                        break;
 320
 321                switch (data->wanted_bits) {
 322                case MCIR2_KEYBOARD_NBITS:
 323                        scancode = data->body & 0xffff;
 324                        IR_dprintk(1, "keyboard data 0x%08x\n", data->body);
 325                        if (dev->timeout)
 326                                delay = usecs_to_jiffies(dev->timeout / 1000);
 327                        else
 328                                delay = msecs_to_jiffies(100);
 329                        mod_timer(&data->rx_timeout, jiffies + delay);
 330                        /* Pass data to keyboard buffer parser */
 331                        ir_mce_kbd_process_keyboard_data(data->idev, scancode);
 332                        break;
 333                case MCIR2_MOUSE_NBITS:
 334                        scancode = data->body & 0x1fffff;
 335                        IR_dprintk(1, "mouse data 0x%06x\n", scancode);
 336                        /* Pass data to mouse buffer parser */
 337                        ir_mce_kbd_process_mouse_data(data->idev, scancode);
 338                        break;
 339                default:
 340                        IR_dprintk(1, "not keyboard or mouse data\n");
 341                        goto out;
 342                }
 343
 344                data->state = STATE_INACTIVE;
 345                input_sync(data->idev);
 346                return 0;
 347        }
 348
 349out:
 350        IR_dprintk(1, "failed at state %i (%uus %s)\n",
 351                   data->state, TO_US(ev.duration), TO_STR(ev.pulse));
 352        data->state = STATE_INACTIVE;
 353        input_sync(data->idev);
 354        return -EINVAL;
 355}
 356
 357static int ir_mce_kbd_register(struct rc_dev *dev)
 358{
 359        struct mce_kbd_dec *mce_kbd = &dev->raw->mce_kbd;
 360        struct input_dev *idev;
 361        int i, ret;
 362
 363        idev = input_allocate_device();
 364        if (!idev)
 365                return -ENOMEM;
 366
 367        snprintf(mce_kbd->name, sizeof(mce_kbd->name),
 368                 "MCE IR Keyboard/Mouse (%s)", dev->driver_name);
 369        strlcat(mce_kbd->phys, "/input0", sizeof(mce_kbd->phys));
 370
 371        idev->name = mce_kbd->name;
 372        idev->phys = mce_kbd->phys;
 373
 374        /* Keyboard bits */
 375        set_bit(EV_KEY, idev->evbit);
 376        set_bit(EV_REP, idev->evbit);
 377        for (i = 0; i < sizeof(kbd_keycodes); i++)
 378                set_bit(kbd_keycodes[i], idev->keybit);
 379
 380        /* Mouse bits */
 381        set_bit(EV_REL, idev->evbit);
 382        set_bit(REL_X, idev->relbit);
 383        set_bit(REL_Y, idev->relbit);
 384        set_bit(BTN_LEFT, idev->keybit);
 385        set_bit(BTN_RIGHT, idev->keybit);
 386
 387        /* Report scancodes too */
 388        set_bit(EV_MSC, idev->evbit);
 389        set_bit(MSC_SCAN, idev->mscbit);
 390
 391        setup_timer(&mce_kbd->rx_timeout, mce_kbd_rx_timeout,
 392                    (unsigned long)mce_kbd);
 393
 394        input_set_drvdata(idev, mce_kbd);
 395
 396#if 0
 397        /* Adding this reference means two input devices are associated with
 398         * this rc-core device, which ir-keytable doesn't cope with yet */
 399        idev->dev.parent = &dev->dev;
 400#endif
 401
 402        ret = input_register_device(idev);
 403        if (ret < 0) {
 404                input_free_device(idev);
 405                return -EIO;
 406        }
 407
 408        mce_kbd->idev = idev;
 409
 410        return 0;
 411}
 412
 413static int ir_mce_kbd_unregister(struct rc_dev *dev)
 414{
 415        struct mce_kbd_dec *mce_kbd = &dev->raw->mce_kbd;
 416        struct input_dev *idev = mce_kbd->idev;
 417
 418        del_timer_sync(&mce_kbd->rx_timeout);
 419        input_unregister_device(idev);
 420
 421        return 0;
 422}
 423
 424static struct ir_raw_handler mce_kbd_handler = {
 425        .protocols      = RC_TYPE_MCE_KBD,
 426        .decode         = ir_mce_kbd_decode,
 427        .raw_register   = ir_mce_kbd_register,
 428        .raw_unregister = ir_mce_kbd_unregister,
 429};
 430
 431static int __init ir_mce_kbd_decode_init(void)
 432{
 433        ir_raw_handler_register(&mce_kbd_handler);
 434
 435        printk(KERN_INFO "IR MCE Keyboard/mouse protocol handler initialized\n");
 436        return 0;
 437}
 438
 439static void __exit ir_mce_kbd_decode_exit(void)
 440{
 441        ir_raw_handler_unregister(&mce_kbd_handler);
 442}
 443
 444module_init(ir_mce_kbd_decode_init);
 445module_exit(ir_mce_kbd_decode_exit);
 446
 447MODULE_LICENSE("GPL");
 448MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>");
 449MODULE_DESCRIPTION("MCE Keyboard/mouse IR protocol decoder");
 450