converter/ibmpc_usb/ibmpc_usb.c

   1 /*
   2 Copyright 2019,2020 Jun Wako <wakojun@gmail.com>
   3
   4 This program is free software: you can redistribute it and/or modify
   5 it under the terms of the GNU General Public License as published by
   6 the Free Software Foundation, either version 2 of the License, or
   7 (at your option) any later version.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18 #include <stdint.h>
  19 #include <stdbool.h>
  20 #include "print.h"
  21 #include "util.h"
  22 #include "debug.h"
  23 #include "ibmpc.h"
  24 #include "host.h"
  25 #include "led.h"
  26 #include "matrix.h"
  27 #include "timer.h"
  28 #include "action.h"
  29 #include "ibmpc_usb.h"
  30 #include "ibmpc.h"
  31
  32
  33 static void matrix_make(uint8_t code);
  34 static void matrix_break(uint8_t code);
  35
  36 static int8_t process_cs1(uint8_t code);
  37 static int8_t process_cs2(uint8_t code);
  38 static int8_t process_cs3(uint8_t code);
  39
  40
  41 static uint8_t matrix[MATRIX_ROWS];
  42 #define ROW(code)      ((code>>3)&0x0F)
  43 #define COL(code)      (code&0x07)
  44
  45 static int16_t read_wait(uint16_t wait_ms)
  46 {
  47     uint16_t start = timer_read();
  48     int16_t code;
  49     while ((code = ibmpc_host_recv()) == -1 && timer_elapsed(start) < wait_ms);
  50     return code;
  51 }
  52
  53 static uint16_t read_keyboard_id(void)
  54 {
  55     uint16_t id = 0;
  56     int16_t  code = 0;
  57
  58     // Disable
  59     //code = ibmpc_host_send(0xF5);
  60
  61     // Read ID
  62     code = ibmpc_host_send(0xF2);
  63     if (code == -1) { id = 0xFFFF; goto DONE; }     // XT or No keyboard
  64     if (code != 0xFA) { id = 0xFFFE; goto DONE; }   // Broken PS/2?
  65
  66     // ID takes 500ms max TechRef [8] 4-41
  67     code = read_wait(500);
  68     if (code == -1) { id = 0x0000; goto DONE; }     // AT
  69     id = (code & 0xFF)<<8;
  70
  71     // Mouse responds with one-byte 00, this returns 00FF [y] p.14
  72     code = read_wait(500);
  73     id |= code & 0xFF;
  74
  75 DONE:
  76     // Enable
  77     //code = ibmpc_host_send(0xF4);
  78
  79     return id;
  80 }
  81
  82 void hook_early_init(void)
  83 {
  84     ibmpc_host_init();
  85     ibmpc_host_enable();
  86 }
  87
  88 void matrix_init(void)
  89 {
  90     debug_enable = true;
  91
  92     // initialize matrix state: all keys off
  93     for (uint8_t i=0; i < MATRIX_ROWS; i++) matrix[i] = 0x00;
  94
  95     return;
  96 }
  97
  98 /*
  99  * keyboard recognition
 100  *
 101  * 1. Send F2 to get keyboard ID
 102  *      a. no ACK(FA): XT keyobard
 103  *      b. ACK but no ID: 84-key AT keyboard CodeSet2
 104  *      c. ID is AB 83: PS/2 keyboard CodeSet2
 105  *      d. ID is BF BF: Terminal keyboard CodeSet3
 106  *      e. error on recv: maybe broken PS/2
 107  */
 108 uint8_t current_protocol = 0;
 109 uint16_t keyboard_id = 0x0000;
 110 keyboard_kind_t keyboard_kind = NONE;
 111 uint8_t matrix_scan(void)
 112 {
 113     // scan code reading states
 114     static enum {
 115         INIT,
 116         WAIT_SETTLE,
 117         AT_RESET,
 118         XT_RESET,
 119         XT_RESET_WAIT,
 120         XT_RESET_DONE,
 121         WAIT_AA,
 122         WAIT_AABF,
 123         WAIT_AABFBF,
 124         READ_ID,
 125         SETUP,
 126         LOOP,
 127     } state = INIT;
 128     static uint16_t init_time;
 129
 130
 131     if (ibmpc_error) {
 132         xprintf("\nERR:%02X ISR:%04X ", ibmpc_error, ibmpc_isr_debug);
 133
 134         // when recv error, neither send error nor buffer full
 135         if (!(ibmpc_error & (IBMPC_ERR_SEND | IBMPC_ERR_FULL))) {
 136             // keyboard init again
 137             if (state == LOOP) {
 138                 state = INIT;
 139             }
 140         }
 141
 142         // clear or process error
 143         ibmpc_error = IBMPC_ERR_NONE;
 144         ibmpc_isr_debug = 0;
 145     }
 146
 147     // check protocol AT/XT
 148     if (ibmpc_protocol && ibmpc_protocol != current_protocol) {
 149         xprintf("\nPROTO:%02X ISR:%04X ", ibmpc_protocol, ibmpc_isr_debug);
 150         current_protocol = ibmpc_protocol;
 151         ibmpc_isr_debug = 0;
 152     }
 153
 154     switch (state) {
 155         case INIT:
 156             ibmpc_host_disable();
 157
 158             xprintf("I%u ", timer_read());
 159             keyboard_kind = NONE;
 160             keyboard_id = 0x0000;
 161
 162             matrix_clear();
 163             clear_keyboard();
 164
 165             init_time = timer_read();
 166             state = WAIT_SETTLE;
 167             break;
 168         case WAIT_SETTLE:
 169             // wait for keyboard to settle after plugin
 170             if (timer_elapsed(init_time) > 1000) {
 171                 state = AT_RESET;
 172             }
 173             break;
 174         case AT_RESET:
 175             ibmpc_host_isr_clear();
 176             ibmpc_host_enable();
 177             wait_ms(1); // keyboard can't respond to command without this
 178
 179             // SKIDATA-2-DE(and some other keyboards?) stores 'Code Set' setting in nonvlatile memory
 180             // and keeps it until receiving reset. Sending reset here may be useful to clear it, perhaps.
 181             // https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-AT-Keyboard-Protocol#select-alternate-scan-codesf0
 182
 183             // reset command
 184             if (0xFA == ibmpc_host_send(0xFF)) {
 185                 state = WAIT_AA;
 186             } else {
 187                 state = XT_RESET;
 188             }
 189             xprintf("A%u ", timer_read());
 190             break;
 191         case XT_RESET:
 192             // Reset XT-initialize keyboard
 193             // XT: hard reset 500ms for IBM XT Type-1 keyboard and clones
 194             // XT: soft reset 20ms min(clock Lo)
 195             ibmpc_host_disable();   // soft reset: inihibit(clock Lo/Data Hi)
 196             IBMPC_RST_LO();         // hard reset: reset pin Lo
 197
 198             init_time = timer_read();
 199             state = XT_RESET_WAIT;
 200             break;
 201         case XT_RESET_WAIT:
 202             if (timer_elapsed(init_time) > 500) {
 203                 state = XT_RESET_DONE;
 204             }
 205             break;
 206         case XT_RESET_DONE:
 207             IBMPC_RST_HIZ();        // hard reset: reset pin HiZ
 208             ibmpc_host_isr_clear();
 209             ibmpc_host_enable();    // soft reset: idle(clock Hi/Data Hi)
 210
 211             xprintf("X%u ", timer_read());
 212             init_time = timer_read();
 213             state = WAIT_AA;
 214             break;
 215         case WAIT_AA:
 216             // 1) Read BAT code and ID on keybaord power-up
 217             // For example, XT/AT sends 'AA' and Terminal sends 'AA BF BF' after BAT
 218             // AT 84-key: POR and BAT can take 900-9900ms according to AT TechRef [8] 4-7
 219             // AT 101/102-key: POR and BAT can take 450-2500ms according to AT TechRef [8] 4-39
 220             // 2) Read key typed by user or anything after error on protocol or scan code
 221             // This can happen in case of keyboard hotswap, unstable hardware, signal integrity problem or bug
 222
 223             /* wait until keyboard sends any code without 10000ms timeout
 224             if (timer_elapsed(init_time) > 10000) {
 225                 state = READ_ID;
 226             }
 227             */
 228             if (ibmpc_host_recv() != -1) {  // wait for AA
 229                 xprintf("W%u ", timer_read());
 230                 init_time = timer_read();
 231                 state = WAIT_AABF;
 232             }
 233             break;
 234         case WAIT_AABF:
 235             // NOTE: we can omit to wait BF BF
 236             // ID takes 500ms max? TechRef [8] 4-41, though 1ms is enough for 122-key Terminal 6110345
 237             if (timer_elapsed(init_time) > 500) {
 238                 state = READ_ID;
 239             }
 240             if (ibmpc_host_recv() != -1) {  // wait for BF
 241                 xprintf("W%u ", timer_read());
 242                 init_time = timer_read();
 243                 state = WAIT_AABFBF;
 244             }
 245             break;
 246         case WAIT_AABFBF:
 247             if (timer_elapsed(init_time) > 500) {
 248                 state = READ_ID;
 249             }
 250             if (ibmpc_host_recv() != -1) {  // wait for BF
 251                 xprintf("W%u ", timer_read());
 252                 state = READ_ID;
 253             }
 254             break;
 255         case READ_ID:
 256             keyboard_id = read_keyboard_id();
 257             xprintf("R%u ", timer_read());
 258
 259             if (0x0000 == keyboard_id) {            // CodeSet2 AT(IBM PC AT 84-key)
 260                 keyboard_kind = PC_AT;
 261             } else if (0xFFFF == keyboard_id) {     // CodeSet1 XT
 262                 keyboard_kind = PC_XT;
 263             } else if (0xFFFE == keyboard_id) {     // CodeSet2 PS/2 fails to response?
 264                 keyboard_kind = PC_AT;
 265             } else if (0x00FF == keyboard_id) {     // Mouse is not supported
 266                 xprintf("Mouse: not supported\n");
 267                 keyboard_kind = NONE;
 268 #ifdef G80_2551_SUPPORT
 269             } else if (0xAB86 == keyboard_id ||
 270                        0xAB85 == keyboard_id) {     // For G80-2551 and other 122-key terminal
 271                 // https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-AT-Keyboard-Protocol#ab86
 272                 // https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-AT-Keyboard-Protocol#ab85
 273
 274                 if ((0xFA == ibmpc_host_send(0xF0)) &&
 275                     (0xFA == ibmpc_host_send(0x03))) {
 276                     // switch to code set 3
 277                     keyboard_kind = PC_TERMINAL;
 278                 } else {
 279                     keyboard_kind = PC_AT;
 280                 }
 281 #endif
 282             } else if (0xBFB0 == keyboard_id) {     // IBM RT Keyboard
 283                 // https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-AT-Keyboard-Protocol#bfb0
 284                 // TODO: LED indicator fix
 285                 //keyboard_kind = PC_TERMINAL_IBM_RT;
 286                 keyboard_kind = PC_TERMINAL;
 287             } else if (0xAB00 == (keyboard_id & 0xFF00)) {  // CodeSet2 PS/2
 288                 keyboard_kind = PC_AT;
 289             } else if (0xBF00 == (keyboard_id & 0xFF00)) {  // CodeSet3 Terminal
 290                 keyboard_kind = PC_TERMINAL;
 291             } else {
 292                 keyboard_kind = PC_AT;
 293             }
 294
 295             xprintf("\nID:%04X(%d) ", keyboard_id, keyboard_kind);
 296
 297             state = SETUP;
 298             break;
 299         case SETUP:
 300             xprintf("S%u ", timer_read());
 301             switch (keyboard_kind) {
 302                 case PC_XT:
 303                     break;
 304                 case PC_AT:
 305                     led_set(host_keyboard_leds());
 306                     break;
 307                 case PC_TERMINAL:
 308                     // Set all keys to make/break type
 309                     ibmpc_host_send(0xF8);
 310                     // This should not be harmful
 311                     led_set(host_keyboard_leds());
 312                     break;
 313                 default:
 314                     break;
 315             }
 316             state = LOOP;
 317             xprintf("L%u ", timer_read());
 318         case LOOP:
 319             {
 320                 uint16_t code = ibmpc_host_recv();
 321                 if (code == -1) {
 322                     // no code
 323                     break;
 324                 }
 325
 326                 // Keyboard Error/Overrun([3]p.26) or Buffer full
 327                 // Scan Code Set 1: 0xFF
 328                 // Scan Code Set 2 and 3: 0x00
 329                 // Buffer full(IBMPC_ERR_FULL): 0xFF
 330                 if (code == 0x00 || code == 0xFF) {
 331                     xprintf("\n!OVERRUN![");
 332
 333                     // read and ignore data
 334                     do {
 335                         wait_ms(10);
 336                     } while ((code = ibmpc_host_recv()) != -1);
 337                     xprintf("]\n");
 338
 339                     // clear stuck keys
 340                     matrix_clear();
 341                     clear_keyboard();
 342                     break;
 343                 }
 344
 345                 switch (keyboard_kind) {
 346                     case PC_XT:
 347                         if (process_cs1(code) == -1) state = INIT;
 348                         break;
 349                     case PC_AT:
 350                         if (process_cs2(code) == -1) state = INIT;
 351                         break;
 352                     case PC_TERMINAL:
 353                         if (process_cs3(code) == -1) state = INIT;
 354                         break;
 355                     default:
 356                         break;
 357                 }
 358             }
 359             break;
 360         default:
 361             break;
 362     }
 363     return 1;
 364 }
 365
 366 inline
 367 bool matrix_is_on(uint8_t row, uint8_t col)
 368 {
 369     return (matrix[row] & (1<<col));
 370 }
 371
 372 inline
 373 uint8_t matrix_get_row(uint8_t row)
 374 {
 375     return matrix[row];
 376 }
 377
 378 uint8_t matrix_key_count(void)
 379 {
 380     uint8_t count = 0;
 381     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
 382         count += bitpop(matrix[i]);
 383     }
 384     return count;
 385 }
 386
 387
 388 inline
 389 static void matrix_make(uint8_t code)
 390 {
 391     if (!matrix_is_on(ROW(code), COL(code))) {
 392         matrix[ROW(code)] |= 1<<COL(code);
 393     }
 394 }
 395
 396 inline
 397 static void matrix_break(uint8_t code)
 398 {
 399     if (matrix_is_on(ROW(code), COL(code))) {
 400         matrix[ROW(code)] &= ~(1<<COL(code));
 401     }
 402 }
 403
 404 void matrix_clear(void)
 405 {
 406     for (uint8_t i=0; i < MATRIX_ROWS; i++) matrix[i] = 0x00;
 407 }
 408
 409 void led_set(uint8_t usb_led)
 410 {
 411     // Sending before keyboard recognition may be harmful for XT keyboard
 412     if (keyboard_kind == NONE) return;
 413
 414     // XT keyobard doesn't support any command and it is harmful perhaps
 415     // https://github.com/tmk/tmk_keyboard/issues/635#issuecomment-626993437
 416     if (keyboard_kind == PC_XT) return;
 417
 418     // It should be safe to send the command to keyboards with AT protocol
 419     // - IBM Terminal doesn't support the command and response with 0xFE but it is not harmful.
 420     // - Some other Terminals like G80-2551 supports the command.
 421     //   https://geekhack.org/index.php?topic=103648.msg2894921#msg2894921
 422
 423     // TODO: PC_TERMINAL_IBM_RT support
 424     uint8_t ibmpc_led = 0;
 425     if (usb_led &  (1<<USB_LED_SCROLL_LOCK))
 426         ibmpc_led |= (1<<IBMPC_LED_SCROLL_LOCK);
 427     if (usb_led &  (1<<USB_LED_NUM_LOCK))
 428         ibmpc_led |= (1<<IBMPC_LED_NUM_LOCK);
 429     if (usb_led &  (1<<USB_LED_CAPS_LOCK))
 430         ibmpc_led |= (1<<IBMPC_LED_CAPS_LOCK);
 431     ibmpc_host_set_led(ibmpc_led);
 432 }
 433
 434
 435 /*******************************************************************************
 436  * XT: Scan Code Set 1
 437  *
 438  * See [3], [a]
 439  *
 440  * E0-escaped scan codes are translated into unused range of the matrix.(54-7F)
 441  *
 442  *     01-53: Normal codes used in original XT keyboard
 443  *     54-7F: Not used in original XT keyboard
 444  *
 445  *         0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F
 446  *     50  -   -   -   -   *   *   x   x   x   x   *   *   *   *   *   *
 447  *     60  *   *   *   *   x   x   x   x   x   x   x   x   x   x   x   *
 448  *     70  x   *   *   x   *   *   x   *   *   x   *   x   *   x   x   *
 449  *
 450  * -: codes existed in original XT keyboard
 451  * *: E0-escaped codes translated
 452  * x: Non-espcaped codes(Some are not used in real keyboards probably)
 453  *
 454  * Codes assigned in range 54-7F:
 455  *
 456  *     50  -                60  Up*                 70  KANAx
 457  *     51  -                61  Left*               71  Insert*
 458  *     52  -                62  Down*               72  Delete*
 459  *     53  -                63  Right*              73  ROx
 460  *     54  PrintScr*        64  F13x                74  Home*
 461  *     55  Pause*           65  F14x                75  End*
 462  *     56  Euro2x           66  F15x                76  F24x
 463  *     57  F11x             67  F16x                77  PageUp*
 464  *     58  F12x             68  F17x                78  PageDown*
 465  *     59  Keypad=x         69  F18x                79  HENKANx
 466  *     5A  LGUI*            6A  F19x                7A  RCTL*
 467  *     5B  RGUI*            6B  F20x                7B  MUHENKANx
 468  *     5C  APP*             6C  F21x                7C  RALT*
 469  *     5D  Mute*            6D  F22x                7D  JPYx
 470  *     5E  Volume Down*     6E  F23x                7E  Keypad,x
 471  *     5F  Volume Up*       6F  Keypad Enter*       7F  Keypad/ *
 472  */
 473 static uint8_t cs1_e0code(uint8_t code) {
 474     switch(code) {
 475         // Original IBM XT keyboard doesn't use E0-codes probably
 476         // Some XT compatilble keyobards need these keys?
 477         case 0x37: return 0x54; // Print Screen
 478         case 0x46: return 0x55; // Ctrl + Pause
 479         case 0x5B: return 0x5A; // Left  GUI
 480         case 0x5C: return 0x5B; // Right GUI
 481         case 0x5D: return 0x5C; // Application
 482         case 0x20: return 0x5D; // Mute
 483         case 0x2E: return 0x5E; // Volume Down
 484         case 0x30: return 0x5F; // Volume Up
 485         case 0x48: return 0x60; // Up
 486         case 0x4B: return 0x61; // Left
 487         case 0x50: return 0x62; // Down
 488         case 0x4D: return 0x63; // Right
 489         case 0x1C: return 0x6F; // Keypad Enter
 490         case 0x52: return 0x71; // Insert
 491         case 0x53: return 0x72; // Delete
 492         case 0x47: return 0x74; // Home
 493         case 0x4F: return 0x75; // End
 494         case 0x49: return 0x77; // Page Up
 495         case 0x51: return 0x78; // Page Down
 496         case 0x1D: return 0x7A; // Right Ctrl
 497         case 0x38: return 0x7C; // Right Alt
 498         case 0x35: return 0x7F; // Keypad /
 499
 500         // Shared matrix cell with other keys
 501         case 0x5E: return 0x70; // Power (KANA)
 502         case 0x5F: return 0x79; // Sleep (HENKAN)
 503         case 0x63: return 0x7B; // Wake  (MUHENKAN)
 504
 505         default:
 506            xprintf("!CS1_E0_%02X!\n", code);
 507            return code;
 508     }
 509     return 0x00;
 510 }
 511
 512 static int8_t process_cs1(uint8_t code)
 513 {
 514     static enum {
 515         INIT,
 516         E0,
 517         // Pause: E1 1D 45, E1 9D C5 [a] (TODO: test)
 518         E1,
 519         E1_1D,
 520         E1_9D,
 521     } state = INIT;
 522
 523     switch (state) {
 524         case INIT:
 525             switch (code) {
 526                 case 0xE0:
 527                     state = E0;
 528                     break;
 529                 case 0xE1:
 530                     state = E1;
 531                     break;
 532                 default:
 533                     if (code < 0x80)
 534                         matrix_make(code);
 535                     else
 536                         matrix_break(code & 0x7F);
 537                     break;
 538             }
 539             break;
 540         case E0:
 541             switch (code) {
 542                 case 0x2A:
 543                 case 0xAA:
 544                 case 0x36:
 545                 case 0xB6:
 546                     //ignore fake shift
 547                     state = INIT;
 548                     break;
 549                 default:
 550                     if (code < 0x80)
 551                         matrix_make(cs1_e0code(code));
 552                     else
 553                         matrix_break(cs1_e0code(code & 0x7F));
 554                     state = INIT;
 555                     break;
 556             }
 557             break;
 558         case E1:
 559             switch (code) {
 560                 case 0x1D:
 561                     state = E1_1D;
 562                     break;
 563                 case 0x9D:
 564                     state = E1_9D;
 565                     break;
 566                 default:
 567                     state = INIT;
 568                     break;
 569             }
 570             break;
 571         case E1_1D:
 572             switch (code) {
 573                 case 0x45:
 574                     matrix_make(0x55);
 575                     break;
 576                 default:
 577                     state = INIT;
 578                     break;
 579             }
 580             break;
 581         case E1_9D:
 582             switch (code) {
 583                 case 0x45:
 584                     matrix_break(0x55);
 585                     break;
 586                 default:
 587                     state = INIT;
 588                     break;
 589             }
 590             break;
 591         default:
 592             state = INIT;
 593     }
 594     return 0;
 595 }
 596
 597
 598 /*******************************************************************************
 599  * AT, PS/2: Scan Code Set 2
 600  *
 601  * Exceptional Handling
 602  * --------------------
 603  * Some keys should be handled exceptionally. See [b].
 604  *
 605  * Scan codes are varied or prefix/postfix'd depending on modifier key state.
 606  *
 607  * 1) Insert, Delete, Home, End, PageUp, PageDown, Up, Down, Right, Left
 608  *     a) when Num Lock is off
 609  *     modifiers | make                      | break
 610  *     ----------+---------------------------+----------------------
 611  *     Ohter     |                    <make> | <break>
 612  *     LShift    | E0 F0 12           <make> | <break>  E0 12
 613  *     RShift    | E0 F0 59           <make> | <break>  E0 59
 614  *     L+RShift  | E0 F0 12  E0 F0 59 <make> | <break>  E0 59 E0 12
 615  *
 616  *     b) when Num Lock is on
 617  *     modifiers | make                      | break
 618  *     ----------+---------------------------+----------------------
 619  *     Other     | E0 12              <make> | <break>  E0 F0 12
 620  *     Shift'd   |                    <make> | <break>
 621  *
 622  *     Handling: These prefix/postfix codes are ignored.
 623  *
 624  *
 625  * 2) Keypad /
 626  *     modifiers | make                      | break
 627  *     ----------+---------------------------+----------------------
 628  *     Ohter     |                    <make> | <break>
 629  *     LShift    | E0 F0 12           <make> | <break>  E0 12
 630  *     RShift    | E0 F0 59           <make> | <break>  E0 59
 631  *     L+RShift  | E0 F0 12  E0 F0 59 <make> | <break>  E0 59 E0 12
 632  *
 633  *     Handling: These prefix/postfix codes are ignored.
 634  *
 635  *
 636  * 3) PrintScreen
 637  *     modifiers | make         | break
 638  *     ----------+--------------+-----------------------------------
 639  *     Other     | E0 12  E0 7C | E0 F0 7C  E0 F0 12
 640  *     Shift'd   |        E0 7C | E0 F0 7C
 641  *     Control'd |        E0 7C | E0 F0 7C
 642  *     Alt'd     |           84 | F0 84
 643  *
 644  *     Handling: These prefix/postfix codes are ignored, and both scan codes
 645  *               'E0 7C' and 84 are seen as PrintScreen.
 646  *
 647  * 4) Pause
 648  *     modifiers | make(no break code)
 649  *     ----------+--------------------------------------------------
 650  *     Other     | E1 14 77 E1 F0 14 F0 77
 651  *     Control'd | E0 7E E0 F0 7E
 652  *
 653  *     Handling: Both code sequences are treated as a whole.
 654  *               And we need a ad hoc 'pseudo break code' hack to get the key off
 655  *               because it has no break code.
 656  *
 657  * Notes:
 658  * 'Hanguel/English'(F1) and 'Hanja'(F2) have no break code. See [a].
 659  * These two Korean keys need exceptional handling and are not supported for now.
 660  *
 661  */
 662 static uint8_t cs2_e0code(uint8_t code) {
 663     switch(code) {
 664         // E0 prefixed codes translation See [a].
 665         case 0x11: return 0x0F; // right alt
 666         case 0x14: return 0x17; // right control
 667         case 0x1F: return 0x19; // left GUI
 668         case 0x27: return 0x1F; // right GUI
 669         case 0x2F: return 0x5C; // apps
 670         case 0x4A: return 0x60; // keypad /
 671         case 0x5A: return 0x62; // keypad enter
 672         case 0x69: return 0x27; // end
 673         case 0x6B: return 0x53; // cursor left
 674         case 0x6C: return 0x2F; // home
 675         case 0x70: return 0x39; // insert
 676         case 0x71: return 0x37; // delete
 677         case 0x72: return 0x3F; // cursor down
 678         case 0x74: return 0x47; // cursor right
 679         case 0x75: return 0x4F; // cursor up
 680         case 0x7A: return 0x56; // page down
 681         case 0x7D: return 0x5E; // page up
 682         case 0x7C: return 0x7F; // Print Screen
 683         case 0x7E: return 0x00; // Control'd Pause
 684
 685         case 0x21: return 0x65; // volume down
 686         case 0x32: return 0x6E; // volume up
 687         case 0x23: return 0x6F; // mute
 688         case 0x10: return 0x08; // (WWW search)     -> F13
 689         case 0x18: return 0x10; // (WWW favourites) -> F14
 690         case 0x20: return 0x18; // (WWW refresh)    -> F15
 691         case 0x28: return 0x20; // (WWW stop)       -> F16
 692         case 0x30: return 0x28; // (WWW forward)    -> F17
 693         case 0x38: return 0x30; // (WWW back)       -> F18
 694         case 0x3A: return 0x38; // (WWW home)       -> F19
 695         case 0x40: return 0x40; // (my computer)    -> F20
 696         case 0x48: return 0x48; // (email)          -> F21
 697         case 0x2B: return 0x50; // (calculator)     -> F22
 698         case 0x34: return 0x08; // (play/pause)     -> F13
 699         case 0x3B: return 0x10; // (stop)           -> F14
 700         case 0x15: return 0x18; // (previous track) -> F15
 701         case 0x4D: return 0x20; // (next track)     -> F16
 702         case 0x50: return 0x28; // (media select)   -> F17
 703         case 0x5E: return 0x50; // (ACPI wake)      -> F22
 704         case 0x3F: return 0x57; // (ACPI sleep)     -> F23
 705         case 0x37: return 0x5F; // (ACPI power)     -> F24
 706
 707         // https://github.com/tmk/tmk_keyboard/pull/636
 708         case 0x03: return 0x18; // Help        DEC LK411 -> F15
 709         case 0x04: return 0x08; // F13         DEC LK411
 710         case 0x0B: return 0x20; // Do          DEC LK411 -> F16
 711         case 0x0C: return 0x10; // F14         DEC LK411
 712         case 0x0D: return 0x19; // LCompose    DEC LK411 -> LGUI
 713         case 0x79: return 0x6D; // KP-         DEC LK411 -> PCMM
 714         case 0x83: return 0x28; // F17         DEC LK411
 715         default: return (code & 0x7F);
 716     }
 717 }
 718
 719 static int8_t process_cs2(uint8_t code)
 720 {
 721     // scan code reading states
 722     static enum {
 723         INIT,
 724         F0,
 725         E0,
 726         E0_F0,
 727         // Pause
 728         E1,
 729         E1_14,
 730         E1_F0,
 731         E1_F0_14,
 732         E1_F0_14_F0,
 733     } state = INIT;
 734
 735     switch (state) {
 736         case INIT:
 737             switch (code) {
 738                 case 0xE0:
 739                     state = E0;
 740                     break;
 741                 case 0xF0:
 742                     state = F0;
 743                     break;
 744                 case 0xE1:
 745                     state = E1;
 746                     break;
 747                 case 0x83:  // F7
 748                     matrix_make(0x02);
 749                     state = INIT;
 750                     break;
 751                 case 0x84:  // Alt'd PrintScreen
 752                     matrix_make(0x7F);
 753                     state = INIT;
 754                     break;
 755                 case 0xAA:  // Self-test passed
 756                 case 0xFC:  // Self-test failed
 757                     // replug or unstable connection probably
 758                 default:    // normal key make
 759                     state = INIT;
 760                     if (code < 0x80) {
 761                         matrix_make(code);
 762                     } else {
 763                         matrix_clear();
 764                         xprintf("!CS2_INIT!\n");
 765                         return -1;
 766                     }
 767             }
 768             break;
 769         case E0:    // E0-Prefixed
 770             switch (code) {
 771                 case 0x12:  // to be ignored
 772                 case 0x59:  // to be ignored
 773                     state = INIT;
 774                     break;
 775                 case 0xF0:
 776                     state = E0_F0;
 777                     break;
 778                 default:
 779                     state = INIT;
 780                     if (code < 0x80) {
 781                         matrix_make(cs2_e0code(code));
 782                     } else {
 783                         matrix_clear();
 784                         xprintf("!CS2_E0!\n");
 785                         return -1;
 786                     }
 787             }
 788             break;
 789         case F0:    // Break code
 790             switch (code) {
 791                 case 0x83:  // F7
 792                     matrix_break(0x02);
 793                     state = INIT;
 794                     break;
 795                 case 0x84:  // Alt'd PrintScreen
 796                     matrix_break(0x7F);
 797                     state = INIT;
 798                     break;
 799                 default:
 800                     state = INIT;
 801                     if (code < 0x80) {
 802                         matrix_break(code);
 803                     } else {
 804                         matrix_clear();
 805                         xprintf("!CS2_F0!\n");
 806                         return -1;
 807                     }
 808             }
 809             break;
 810         case E0_F0: // Break code of E0-prefixed
 811             switch (code) {
 812                 case 0x12:  // to be ignored
 813                 case 0x59:  // to be ignored
 814                     state = INIT;
 815                     break;
 816                 default:
 817                     state = INIT;
 818                     if (code < 0x80) {
 819                         matrix_break(cs2_e0code(code));
 820                     } else {
 821                         matrix_clear();
 822                         xprintf("!CS2_E0_F0!\n");
 823                         return -1;
 824                     }
 825             }
 826             break;
 827         // Pause make: E1 14 77
 828         case E1:
 829             switch (code) {
 830                 case 0x14:
 831                     state = E1_14;
 832                     break;
 833                 case 0xF0:
 834                     state = E1_F0;
 835                     break;
 836                 default:
 837                     state = INIT;
 838             }
 839             break;
 840         case E1_14:
 841             switch (code) {
 842                 case 0x77:
 843                     matrix_make(0x00);
 844                     state = INIT;
 845                     break;
 846                 default:
 847                     state = INIT;
 848             }
 849             break;
 850         // Pause break: E1 F0 14 F0 77
 851         case E1_F0:
 852             switch (code) {
 853                 case 0x14:
 854                     state = E1_F0_14;
 855                     break;
 856                 default:
 857                     state = INIT;
 858             }
 859             break;
 860         case E1_F0_14:
 861             switch (code) {
 862                 case 0xF0:
 863                     state = E1_F0_14_F0;
 864                     break;
 865                 default:
 866                     state = INIT;
 867             }
 868             break;
 869         case E1_F0_14_F0:
 870             switch (code) {
 871                 case 0x77:
 872                     matrix_break(0x00);
 873                     state = INIT;
 874                     break;
 875                 default:
 876                     state = INIT;
 877             }
 878             break;
 879         default:
 880             state = INIT;
 881     }
 882     return 0;
 883 }
 884
 885 /*
 886  * Terminal: Scan Code Set 3
 887  *
 888  * See [3], [7] and
 889  * https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-AT-Keyboard-Protocol#scan-code-set-3
 890  */
 891 static int8_t process_cs3(uint8_t code)
 892 {
 893     static enum {
 894         READY,
 895         F0,
 896 #ifdef G80_2551_SUPPORT
 897         // G80-2551 four extra keys around cursor keys
 898         G80,
 899         G80_F0,
 900 #endif
 901     } state = READY;
 902
 903     switch (state) {
 904         case READY:
 905             switch (code) {
 906                 case 0xF0:
 907                     state = F0;
 908                     break;
 909                 case 0x83:  // PrintScreen
 910                     matrix_make(0x02);
 911                     break;
 912                 case 0x84:  // Keypad *
 913                     matrix_make(0x7F);
 914                     break;
 915                 case 0x85:  // Muhenkan
 916                     matrix_make(0x0B);
 917                     break;
 918                 case 0x86:  // Henkan
 919                     matrix_make(0x06);
 920                     break;
 921                 case 0x87:  // Hiragana
 922                     matrix_make(0x00);
 923                     break;
 924                 case 0x8B:  // Left GUI
 925                     matrix_make(0x01);
 926                     break;
 927                 case 0x8C:  // Right GUI
 928                     matrix_make(0x09);
 929                     break;
 930                 case 0x8D:  // Application
 931                     matrix_make(0x0A);
 932                     break;
 933 #ifdef G80_2551_SUPPORT
 934                 case 0x80:  // G80-2551 four extra keys around cursor keys
 935                     state = G80;
 936                     break;
 937 #endif
 938                 default:    // normal key make
 939                     if (code < 0x80) {
 940                         matrix_make(code);
 941                     } else {
 942                         xprintf("!CS3_READY!\n");
 943                         return -1;
 944                     }
 945             }
 946             break;
 947         case F0:    // Break code
 948             switch (code) {
 949                 case 0x83:  // PrintScreen
 950                     matrix_break(0x02);
 951                     state = READY;
 952                     break;
 953                 case 0x84:  // Keypad *
 954                     matrix_break(0x7F);
 955                     state = READY;
 956                     break;
 957                 case 0x85:  // Muhenkan
 958                     matrix_break(0x0B);
 959                     state = READY;
 960                     break;
 961                 case 0x86:  // Henkan
 962                     matrix_break(0x06);
 963                     state = READY;
 964                     break;
 965                 case 0x87:  // Hiragana
 966                     matrix_break(0x00);
 967                     state = READY;
 968                     break;
 969                 case 0x8B:  // Left GUI
 970                     matrix_break(0x01);
 971                     state = READY;
 972                     break;
 973                 case 0x8C:  // Right GUI
 974                     matrix_break(0x09);
 975                     state = READY;
 976                     break;
 977                 case 0x8D:  // Application
 978                     matrix_break(0x0A);
 979                     state = READY;
 980                     break;
 981                 default:
 982                     state = READY;
 983                     if (code < 0x80) {
 984                         matrix_break(code);
 985                     } else {
 986                         xprintf("!CS3_F0!\n");
 987                         return -1;
 988                     }
 989             }
 990             break;
 991 #ifdef G80_2551_SUPPORT
 992         /*
 993          * G80-2551 terminal keyboard support
 994          * https://deskthority.net/wiki/Cherry_G80-2551
 995          * https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-AT-Keyboard-Protocol#g80-2551-in-code-set-3
 996          */
 997         case G80:   // G80-2551 four extra keys around cursor keys
 998             switch (code) {
 999                 case (0x26):    // TD= -> JYEN
1000                     matrix_make(0x5D);
1001                     break;
1002                 case (0x25):    // page with edge -> NUHS
1003                     matrix_make(0x53);
1004                     break;
1005                 case (0x16):    // two pages -> RO
1006                     matrix_make(0x51);
1007                     break;
1008                 case (0x1E):    // calc -> KANA
1009                     matrix_make(0x00);
1010                     break;
1011                 case (0xF0):
1012                     state = G80_F0;
1013                     return 0;
1014                 default:
1015                     // Not supported
1016                     matrix_clear();
1017                     break;
1018             }
1019             state = READY;
1020             break;
1021         case G80_F0:
1022             switch (code) {
1023                 case (0x26):    // TD= -> JYEN
1024                     matrix_break(0x5D);
1025                     break;
1026                 case (0x25):    // page with edge -> NUHS
1027                     matrix_break(0x53);
1028                     break;
1029                 case (0x16):    // two pages -> RO
1030                     matrix_break(0x51);
1031                     break;
1032                 case (0x1E):    // calc -> KANA
1033                     matrix_break(0x00);
1034                     break;
1035                 default:
1036                     // Not supported
1037                     matrix_clear();
1038                     break;
1039             }
1040             state = READY;
1041             break;
1042 #endif
1043     }
1044     return 0;
1045 }
1046
1047 /*
1048  * IBM PC Keyboard Protocol Resources:
1049  *
1050  * [a] Microsoft USB HID to PS/2 Translation Table - Scan Code Set 1 and 2
1051  * http://download.microsoft.com/download/1/6/1/161ba512-40e2-4cc9-843a-923143f3456c/translate.pdf
1052  *
1053  * [b] Microsoft Keyboard Scan Code Specification - Special rules of Scan Code Set 1 and 2
1054  * http://download.microsoft.com/download/1/6/1/161ba512-40e2-4cc9-843a-923143f3456c/scancode.doc
1055  *
1056  * [1] PS/2 Reference Manuals - Collection of IBM Personal System/2 documents.
1057  * http://www.mcamafia.de/pdf/pdfref.htm
1058  *
1059  * [2] Keyboard and Auxiliary Device Controller - Signal Timing and Format
1060  * http://www.mcamafia.de/pdf/ibm_hitrc07.pdf
1061  *
1062  * [3] Keyboards(101- and 102-key) - Keyboard Layout, Scan Code Set, POR, and Commands.
1063  * http://www.mcamafia.de/pdf/ibm_hitrc11.pdf
1064  *
1065  * [4] IBM PC XT Keyboard Protocol
1066  * https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-XT-Keyboard-Protocol
1067  *
1068  * [5] IBM Keyboard Scan Code by John Elliott - 83-key, 84-key, 102-key and 122-key
1069  * https://www.seasip.info/VintagePC/index.html
1070  *
1071  * [6] IBM 1391406 Keyboard - Scan Code Set 2 of 102-key PS/2 keyboard
1072  * https://www.seasip.info/VintagePC/ibm_1391406.html
1073  *
1074  * [7] The IBM 6110344 Keyboard - Scan Code Set 3 of 122-key terminal keyboard
1075  * https://www.seasip.info/VintagePC/ibm_6110344.html
1076  *
1077  * [8] IBM PC AT Technical Reference 1986
1078  * http://bitsavers.org/pdf/ibm/pc/at/6183355_PC_AT_Technical_Reference_Mar86.pdf
1079  *
1080  * [y] TrackPoint Engineering Specifications for version 3E
1081  * https://web.archive.org/web/20100526161812/http://wwwcssrv.almaden.ibm.com/trackpoint/download.html
1082  *
1083  * [z] [Soarer's XT/AT/PS2/Terminal to USB converter]
1084  * https://geekhack.org/index.php?topic=17458.0
1085  *
1086  */