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(void);
  37 static int8_t process_cs2(void);
  38 static int8_t process_cs3(void);
  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         XT_RESET,
 117         XT_RESET_WAIT,
 118         XT_RESET_DONE,
 119         WAIT_AA,
 120         WAIT_AABF,
 121         WAIT_AABFBF,
 122         READ_ID,
 123         SETUP,
 124         LOOP,
 125     } state = INIT;
 126     static uint16_t init_time;
 127
 128
 129     if (ibmpc_error) {
 130         xprintf("\nERR:%02X\n", ibmpc_error);
 131
 132         // when recv error, neither send error nor buffer full
 133         if (!(ibmpc_error & (IBMPC_ERR_SEND | IBMPC_ERR_FULL))) {
 134             // keyboard init again
 135             if (state == LOOP) {
 136                 xprintf("init\n");
 137                 state = INIT;
 138             }
 139         }
 140
 141         // clear or process error
 142         ibmpc_error = IBMPC_ERR_NONE;
 143     }
 144
 145     // check ISR state debug
 146     if (ibmpc_isr_debug) {
 147         xprintf("\nISR:%04X\n", ibmpc_isr_debug);
 148         ibmpc_isr_debug = 0;
 149     }
 150
 151     // check protocol AT/XT
 152     if (ibmpc_protocol != current_protocol) {
 153         xprintf("\nPROTO:%02X\n", ibmpc_protocol);
 154         current_protocol = ibmpc_protocol;
 155     }
 156
 157     switch (state) {
 158         case INIT:
 159             xprintf("I%u ", timer_read());
 160             keyboard_kind = NONE;
 161             keyboard_id = 0x0000;
 162
 163             matrix_clear();
 164             clear_keyboard();
 165
 166             state = XT_RESET;
 167             break;
 168         case XT_RESET:
 169             // Reset XT-initialize keyboard
 170             // XT: hard reset 500ms for IBM XT Type-1 keyboard and clones
 171             // XT: soft reset 20ms min(clock Lo)
 172             ibmpc_host_disable();   // soft reset: inihibit(clock Lo/Data Hi)
 173             IBMPC_RST_LO();         // hard reset: reset pin Lo
 174
 175             init_time = timer_read();
 176             state = XT_RESET_WAIT;
 177             break;
 178         case XT_RESET_WAIT:
 179             if (timer_elapsed(init_time) > 500) {
 180                 state = XT_RESET_DONE;
 181             }
 182             break;
 183         case XT_RESET_DONE:
 184             IBMPC_RST_HIZ();        // hard reset: reset pin HiZ
 185             ibmpc_host_isr_clear();
 186             ibmpc_host_enable();    // soft reset: idle(clock Hi/Data Hi)
 187
 188             xprintf("X%u ", timer_read());
 189             init_time = timer_read();
 190             state = WAIT_AA;
 191             break;
 192         case WAIT_AA:
 193             // 1) Read BAT code and ID on keybaord power-up
 194             // For example, XT/AT sends 'AA' and Terminal sends 'AA BF BF' after BAT
 195             // AT 84-key: POR and BAT can take 900-9900ms according to AT TechRef [8] 4-7
 196             // AT 101/102-key: POR and BAT can take 450-2500ms according to AT TechRef [8] 4-39
 197             // 2) Read key typed by user or anything after error on protocol or scan code
 198             // This can happen in case of keyboard hotswap, unstable hardware, signal integrity problem or bug
 199
 200             /* wait until keyboard sends any code without 10000ms timeout
 201             if (timer_elapsed(init_time) > 10000) {
 202                 state = READ_ID;
 203             }
 204             */
 205             if (ibmpc_host_recv() != -1) {  // wait for AA
 206                 xprintf("W%u ", timer_read());
 207                 init_time = timer_read();
 208                 state = WAIT_AABF;
 209             }
 210             break;
 211         case WAIT_AABF:
 212             // NOTE: we can omit to wait BF BF
 213             // ID takes 500ms max? TechRef [8] 4-41, though 1ms is enough for 122-key Terminal 6110345
 214             if (timer_elapsed(init_time) > 500) {
 215                 state = READ_ID;
 216             }
 217             if (ibmpc_host_recv() != -1) {  // wait for BF
 218                 xprintf("W%u ", timer_read());
 219                 init_time = timer_read();
 220                 state = WAIT_AABFBF;
 221             }
 222             break;
 223         case WAIT_AABFBF:
 224             if (timer_elapsed(init_time) > 500) {
 225                 state = READ_ID;
 226             }
 227             if (ibmpc_host_recv() != -1) {  // wait for BF
 228                 xprintf("W%u ", timer_read());
 229                 state = READ_ID;
 230             }
 231             break;
 232         case READ_ID:
 233             xprintf("R%u ", timer_read());
 234
 235             // SKIDATA-2-DE(and some other keyboards?) stores 'Code Set' setting in nonvlatile memory
 236             // and keeps it until receiving reset. Sending reset here may be useful to clear it, perhaps.
 237             // https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-AT-Keyboard-Protocol#select-alternate-scan-codesf0
 238             //ibmpc_host_send(0xFF);  // reset command
 239             //read_wait(500);         // BAT takes 600-900ms(84-key) or 300-500ms(101/102-key) [8] 4-7, 4-39
 240
 241             keyboard_id = read_keyboard_id();
 242             if (ibmpc_error) {
 243                 xprintf("\nERR:%02X\n", ibmpc_error);
 244                 ibmpc_error = IBMPC_ERR_NONE;
 245             }
 246
 247             if (0x0000 == keyboard_id) {            // CodeSet2 AT(IBM PC AT 84-key)
 248                 keyboard_kind = PC_AT;
 249             } else if (0xFFFF == keyboard_id) {     // CodeSet1 XT
 250                 keyboard_kind = PC_XT;
 251             } else if (0xFFFE == keyboard_id) {     // CodeSet2 PS/2 fails to response?
 252                 keyboard_kind = PC_AT;
 253             } else if (0x00FF == keyboard_id) {     // Mouse is not supported
 254                 xprintf("Mouse: not supported\n");
 255                 keyboard_kind = NONE;
 256 #ifdef G80_2551_SUPPORT
 257             } else if (0xAB86 == keyboard_id ||
 258                        0xAB85 == keyboard_id) {     // For G80-2551 and other 122-key terminal
 259                 // https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-AT-Keyboard-Protocol#ab86
 260                 // https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-AT-Keyboard-Protocol#ab85
 261
 262                 if ((0xFA == ibmpc_host_send(0xF0)) &&
 263                     (0xFA == ibmpc_host_send(0x03))) {
 264                     // switch to code set 3
 265                     keyboard_kind = PC_TERMINAL;
 266                 } else {
 267                     keyboard_kind = PC_AT;
 268                 }
 269 #endif
 270             } else if (0xBFB0 == keyboard_id) {     // IBM RT Keyboard
 271                 // https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-AT-Keyboard-Protocol#bfb0
 272                 // TODO: LED indicator fix
 273                 //keyboard_kind = PC_TERMINAL_IBM_RT;
 274                 keyboard_kind = PC_TERMINAL;
 275             } else if (0xAB00 == (keyboard_id & 0xFF00)) {  // CodeSet2 PS/2
 276                 keyboard_kind = PC_AT;
 277             } else if (0xBF00 == (keyboard_id & 0xFF00)) {  // CodeSet3 Terminal
 278                 keyboard_kind = PC_TERMINAL;
 279             } else {
 280                 keyboard_kind = PC_AT;
 281             }
 282
 283             xprintf("ID:%04X(%d)\n", keyboard_id, keyboard_kind);
 284
 285             state = SETUP;
 286             break;
 287         case SETUP:
 288             xprintf("S%u ", timer_read());
 289             switch (keyboard_kind) {
 290                 case PC_XT:
 291                     break;
 292                 case PC_AT:
 293                     led_set(host_keyboard_leds());
 294                     break;
 295                 case PC_TERMINAL:
 296                     // Set all keys to make/break type
 297                     ibmpc_host_send(0xF8);
 298                     break;
 299                 default:
 300                     break;
 301             }
 302             state = LOOP;
 303             xprintf("L%u ", timer_read());
 304         case LOOP:
 305             switch (keyboard_kind) {
 306                 case PC_XT:
 307                     if (process_cs1() == -1) state = INIT;
 308                     break;
 309                 case PC_AT:
 310                     if (process_cs2() == -1) state = INIT;
 311                     break;
 312                 case PC_TERMINAL:
 313                     if (process_cs3() == -1) state = INIT;
 314                     break;
 315                 default:
 316                     break;
 317             }
 318             break;
 319         default:
 320             break;
 321     }
 322     return 1;
 323 }
 324
 325 inline
 326 bool matrix_is_on(uint8_t row, uint8_t col)
 327 {
 328     return (matrix[row] & (1<<col));
 329 }
 330
 331 inline
 332 uint8_t matrix_get_row(uint8_t row)
 333 {
 334     return matrix[row];
 335 }
 336
 337 uint8_t matrix_key_count(void)
 338 {
 339     uint8_t count = 0;
 340     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
 341         count += bitpop(matrix[i]);
 342     }
 343     return count;
 344 }
 345
 346
 347 inline
 348 static void matrix_make(uint8_t code)
 349 {
 350     if (!matrix_is_on(ROW(code), COL(code))) {
 351         matrix[ROW(code)] |= 1<<COL(code);
 352     }
 353 }
 354
 355 inline
 356 static void matrix_break(uint8_t code)
 357 {
 358     if (matrix_is_on(ROW(code), COL(code))) {
 359         matrix[ROW(code)] &= ~(1<<COL(code));
 360     }
 361 }
 362
 363 void matrix_clear(void)
 364 {
 365     for (uint8_t i=0; i < MATRIX_ROWS; i++) matrix[i] = 0x00;
 366 }
 367
 368 void led_set(uint8_t usb_led)
 369 {
 370     //if (keyboard_kind != PC_AT) return;
 371
 372     uint8_t ibmpc_led = 0;
 373     if (usb_led &  (1<<USB_LED_SCROLL_LOCK))
 374         ibmpc_led |= (1<<IBMPC_LED_SCROLL_LOCK);
 375     if (usb_led &  (1<<USB_LED_NUM_LOCK))
 376         ibmpc_led |= (1<<IBMPC_LED_NUM_LOCK);
 377     if (usb_led &  (1<<USB_LED_CAPS_LOCK))
 378         ibmpc_led |= (1<<IBMPC_LED_CAPS_LOCK);
 379     ibmpc_host_set_led(ibmpc_led);
 380 }
 381
 382
 383 /*******************************************************************************
 384  * XT: Scan Code Set 1
 385  *
 386  * See [3], [a]
 387  *
 388  * E0-escaped scan codes are translated into unused range of the matrix.(54-7F)
 389  *
 390  *     01-53: Normal codes used in original XT keyboard
 391  *     54-7F: Not used in original XT keyboard
 392  *
 393  *         0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F
 394  *     50  -   -   -   -   *   *   x   x   x   x   *   *   *   *   *   *
 395  *     60  *   *   *   *   x   x   x   x   x   x   x   x   x   x   x   *
 396  *     70  x   *   *   x   *   *   x   *   *   x   *   x   *   x   x   *
 397  *
 398  * -: codes existed in original XT keyboard
 399  * *: E0-escaped codes translated
 400  * x: Non-espcaped codes(Some are not used in real keyboards probably)
 401  *
 402  * Codes assigned in range 54-7F:
 403  *
 404  *     50  -                60  Up*                 70  KANAx
 405  *     51  -                61  Left*               71  Insert*
 406  *     52  -                62  Down*               72  Delete*
 407  *     53  -                63  Right*              73  ROx
 408  *     54  PrintScr*        64  F13x                74  Home*
 409  *     55  Pause*           65  F14x                75  End*
 410  *     56  Euro2x           66  F15x                76  F24x
 411  *     57  F11x             67  F16x                77  PageUp*
 412  *     58  F12x             68  F17x                78  PageDown*
 413  *     59  Keypad=x         69  F18x                79  HENKANx
 414  *     5A  LGUI*            6A  F19x                7A  RCTL*
 415  *     5B  RGUI*            6B  F20x                7B  MUHENKANx
 416  *     5C  APP*             6C  F21x                7C  RALT*
 417  *     5D  Mute*            6D  F22x                7D  JPYx
 418  *     5E  Volume Down*     6E  F23x                7E  Keypad,x
 419  *     5F  Volume Up*       6F  Keypad Enter*       7F  Keypad/ *
 420  */
 421 static uint8_t cs1_e0code(uint8_t code) {
 422     switch(code) {
 423         // Original IBM XT keyboard doesn't use E0-codes probably
 424         // Some XT compatilble keyobards need these keys?
 425         case 0x37: return 0x54; // Print Screen
 426         case 0x46: return 0x55; // Ctrl + Pause
 427         case 0x5B: return 0x5A; // Left  GUI
 428         case 0x5C: return 0x5B; // Right GUI
 429         case 0x5D: return 0x5C; // Application
 430         case 0x20: return 0x5D; // Mute
 431         case 0x2E: return 0x5E; // Volume Down
 432         case 0x30: return 0x5F; // Volume Up
 433         case 0x48: return 0x60; // Up
 434         case 0x4B: return 0x61; // Left
 435         case 0x50: return 0x62; // Down
 436         case 0x4D: return 0x63; // Right
 437         case 0x1C: return 0x6F; // Keypad Enter
 438         case 0x52: return 0x71; // Insert
 439         case 0x53: return 0x72; // Delete
 440         case 0x47: return 0x74; // Home
 441         case 0x4F: return 0x75; // End
 442         case 0x49: return 0x77; // Page Up
 443         case 0x51: return 0x78; // Page Down
 444         case 0x1D: return 0x7A; // Right Ctrl
 445         case 0x38: return 0x7C; // Right Alt
 446         case 0x35: return 0x7F; // Keypad /
 447
 448         // Shared matrix cell with other keys
 449         case 0x5E: return 0x70; // Power (KANA)
 450         case 0x5F: return 0x79; // Sleep (HENKAN)
 451         case 0x63: return 0x7B; // Wake  (MUHENKAN)
 452
 453         default:
 454            xprintf("!CS1_E0_%02X!\n", code);
 455            return code;
 456     }
 457     return 0x00;
 458 }
 459
 460 static int8_t process_cs1(void)
 461 {
 462     static enum {
 463         INIT,
 464         E0,
 465         // Pause: E1 1D 45, E1 9D C5 [a] (TODO: test)
 466         E1,
 467         E1_1D,
 468         E1_9D,
 469     } state = INIT;
 470
 471     uint16_t code = ibmpc_host_recv();
 472     if (code == -1) {
 473         return 0;
 474     }
 475
 476     // Check invalid codes; 0x59-7F won't be used in real XT keyboards probably
 477     // 0x62 is used to handle escape code E0 and E1
 478     if ((code & 0x7F) >= 0x62) {
 479         xprintf("!CS1_INV!\n");
 480         state = INIT;
 481         return -1;
 482     }
 483
 484     switch (state) {
 485         case INIT:
 486             switch (code) {
 487                 case 0x00:
 488                 case 0xFF:  // Error/Overrun [3]p.26
 489                     xprintf("!CS1_ERR!\n");
 490                     return -1;
 491                     break;
 492                 case 0xE0:
 493                     state = E0;
 494                     break;
 495                 case 0xE1:
 496                     state = E1;
 497                     break;
 498                 default:
 499                     if (code < 0x80)
 500                         matrix_make(code);
 501                     else
 502                         matrix_break(code & 0x7F);
 503                     break;
 504             }
 505             break;
 506         case E0:
 507             switch (code) {
 508                 case 0x2A:
 509                 case 0xAA:
 510                 case 0x36:
 511                 case 0xB6:
 512                     //ignore fake shift
 513                     state = INIT;
 514                     break;
 515                 default:
 516                     if (code < 0x80)
 517                         matrix_make(cs1_e0code(code));
 518                     else
 519                         matrix_break(cs1_e0code(code & 0x7F));
 520                     state = INIT;
 521                     break;
 522             }
 523             break;
 524         case E1:
 525             switch (code) {
 526                 case 0x1D:
 527                     state = E1_1D;
 528                     break;
 529                 case 0x9D:
 530                     state = E1_9D;
 531                     break;
 532                 default:
 533                     state = INIT;
 534                     break;
 535             }
 536             break;
 537         case E1_1D:
 538             switch (code) {
 539                 case 0x45:
 540                     matrix_make(0x55);
 541                     break;
 542                 default:
 543                     state = INIT;
 544                     break;
 545             }
 546             break;
 547         case E1_9D:
 548             switch (code) {
 549                 case 0x45:
 550                     matrix_break(0x55);
 551                     break;
 552                 default:
 553                     state = INIT;
 554                     break;
 555             }
 556             break;
 557         default:
 558             state = INIT;
 559     }
 560     return 0;
 561 }
 562
 563
 564 /*******************************************************************************
 565  * AT, PS/2: Scan Code Set 2
 566  *
 567  * Exceptional Handling
 568  * --------------------
 569  * Some keys should be handled exceptionally. See [b].
 570  *
 571  * Scan codes are varied or prefix/postfix'd depending on modifier key state.
 572  *
 573  * 1) Insert, Delete, Home, End, PageUp, PageDown, Up, Down, Right, Left
 574  *     a) when Num Lock is off
 575  *     modifiers | make                      | break
 576  *     ----------+---------------------------+----------------------
 577  *     Ohter     |                    <make> | <break>
 578  *     LShift    | E0 F0 12           <make> | <break>  E0 12
 579  *     RShift    | E0 F0 59           <make> | <break>  E0 59
 580  *     L+RShift  | E0 F0 12  E0 F0 59 <make> | <break>  E0 59 E0 12
 581  *
 582  *     b) when Num Lock is on
 583  *     modifiers | make                      | break
 584  *     ----------+---------------------------+----------------------
 585  *     Other     | E0 12              <make> | <break>  E0 F0 12
 586  *     Shift'd   |                    <make> | <break>
 587  *
 588  *     Handling: These prefix/postfix codes are ignored.
 589  *
 590  *
 591  * 2) Keypad /
 592  *     modifiers | make                      | break
 593  *     ----------+---------------------------+----------------------
 594  *     Ohter     |                    <make> | <break>
 595  *     LShift    | E0 F0 12           <make> | <break>  E0 12
 596  *     RShift    | E0 F0 59           <make> | <break>  E0 59
 597  *     L+RShift  | E0 F0 12  E0 F0 59 <make> | <break>  E0 59 E0 12
 598  *
 599  *     Handling: These prefix/postfix codes are ignored.
 600  *
 601  *
 602  * 3) PrintScreen
 603  *     modifiers | make         | break
 604  *     ----------+--------------+-----------------------------------
 605  *     Other     | E0 12  E0 7C | E0 F0 7C  E0 F0 12
 606  *     Shift'd   |        E0 7C | E0 F0 7C
 607  *     Control'd |        E0 7C | E0 F0 7C
 608  *     Alt'd     |           84 | F0 84
 609  *
 610  *     Handling: These prefix/postfix codes are ignored, and both scan codes
 611  *               'E0 7C' and 84 are seen as PrintScreen.
 612  *
 613  * 4) Pause
 614  *     modifiers | make(no break code)
 615  *     ----------+--------------------------------------------------
 616  *     Other     | E1 14 77 E1 F0 14 F0 77
 617  *     Control'd | E0 7E E0 F0 7E
 618  *
 619  *     Handling: Both code sequences are treated as a whole.
 620  *               And we need a ad hoc 'pseudo break code' hack to get the key off
 621  *               because it has no break code.
 622  *
 623  * Notes:
 624  * 'Hanguel/English'(F1) and 'Hanja'(F2) have no break code. See [a].
 625  * These two Korean keys need exceptional handling and are not supported for now.
 626  *
 627  */
 628 static uint8_t cs2_e0code(uint8_t code) {
 629     switch(code) {
 630         // E0 prefixed codes translation See [a].
 631         case 0x11: return 0x0F; // right alt
 632         case 0x14: return 0x17; // right control
 633         case 0x1F: return 0x19; // left GUI
 634         case 0x27: return 0x1F; // right GUI
 635         case 0x2F: return 0x5C; // apps
 636         case 0x4A: return 0x60; // keypad /
 637         case 0x5A: return 0x62; // keypad enter
 638         case 0x69: return 0x27; // end
 639         case 0x6B: return 0x53; // cursor left
 640         case 0x6C: return 0x2F; // home
 641         case 0x70: return 0x39; // insert
 642         case 0x71: return 0x37; // delete
 643         case 0x72: return 0x3F; // cursor down
 644         case 0x74: return 0x47; // cursor right
 645         case 0x75: return 0x4F; // cursor up
 646         case 0x7A: return 0x56; // page down
 647         case 0x7D: return 0x5E; // page up
 648         case 0x7C: return 0x7F; // Print Screen
 649         case 0x7E: return 0x00; // Control'd Pause
 650
 651         case 0x21: return 0x65; // volume down
 652         case 0x32: return 0x6E; // volume up
 653         case 0x23: return 0x6F; // mute
 654         case 0x10: return 0x08; // (WWW search)     -> F13
 655         case 0x18: return 0x10; // (WWW favourites) -> F14
 656         case 0x20: return 0x18; // (WWW refresh)    -> F15
 657         case 0x28: return 0x20; // (WWW stop)       -> F16
 658         case 0x30: return 0x28; // (WWW forward)    -> F17
 659         case 0x38: return 0x30; // (WWW back)       -> F18
 660         case 0x3A: return 0x38; // (WWW home)       -> F19
 661         case 0x40: return 0x40; // (my computer)    -> F20
 662         case 0x48: return 0x48; // (email)          -> F21
 663         case 0x2B: return 0x50; // (calculator)     -> F22
 664         case 0x34: return 0x08; // (play/pause)     -> F13
 665         case 0x3B: return 0x10; // (stop)           -> F14
 666         case 0x15: return 0x18; // (previous track) -> F15
 667         case 0x4D: return 0x20; // (next track)     -> F16
 668         case 0x50: return 0x28; // (media select)   -> F17
 669         case 0x5E: return 0x50; // (ACPI wake)      -> F22
 670         case 0x3F: return 0x57; // (ACPI sleep)     -> F23
 671         case 0x37: return 0x5F; // (ACPI power)     -> F24
 672
 673         // https://github.com/tmk/tmk_keyboard/pull/636
 674         case 0x03: return 0x18; // Help        DEC LK411 -> F15
 675         case 0x04: return 0x08; // F13         DEC LK411
 676         case 0x0B: return 0x20; // Do          DEC LK411 -> F16
 677         case 0x0C: return 0x10; // F14         DEC LK411
 678         case 0x0D: return 0x19; // LCompose    DEC LK411 -> LGUI
 679         case 0x79: return 0x6D; // KP-         DEC LK411 -> PCMM
 680         case 0x83: return 0x28; // F17         DEC LK411
 681         default: return (code & 0x7F);
 682     }
 683 }
 684
 685 static int8_t process_cs2(void)
 686 {
 687     // scan code reading states
 688     static enum {
 689         INIT,
 690         F0,
 691         E0,
 692         E0_F0,
 693         // Pause
 694         E1,
 695         E1_14,
 696         E1_F0,
 697         E1_F0_14,
 698         E1_F0_14_F0,
 699     } state = INIT;
 700
 701     uint16_t code = ibmpc_host_recv();
 702     if (code == -1) {
 703         return 0;
 704     }
 705
 706     switch (state) {
 707         case INIT:
 708             switch (code) {
 709                 case 0x00:  // Error/Overrun [3]p.26
 710                     xprintf("!CS2_OVR!\n");
 711                     matrix_clear();
 712                     clear_keyboard();
 713                     break;
 714                 case 0xFF:
 715                     matrix_clear();
 716                     xprintf("!CS2_ERR!\n");
 717                     state = INIT;
 718                     return -1;
 719                     break;
 720                 case 0xE0:
 721                     state = E0;
 722                     break;
 723                 case 0xF0:
 724                     state = F0;
 725                     break;
 726                 case 0xE1:
 727                     state = E1;
 728                     break;
 729                 case 0x83:  // F7
 730                     matrix_make(0x02);
 731                     state = INIT;
 732                     break;
 733                 case 0x84:  // Alt'd PrintScreen
 734                     matrix_make(0x7F);
 735                     state = INIT;
 736                     break;
 737                 case 0xAA:  // Self-test passed
 738                 case 0xFC:  // Self-test failed
 739                     // reset or plugin-in new keyboard
 740                     state = INIT;
 741                     return -1;
 742                     break;
 743                 default:    // normal key make
 744                     state = INIT;
 745                     if (code < 0x80) {
 746                         matrix_make(code);
 747                     } else {
 748                         matrix_clear();
 749                         xprintf("!CS2_INIT!\n");
 750                         return -1;
 751                     }
 752             }
 753             break;
 754         case E0:    // E0-Prefixed
 755             switch (code) {
 756                 case 0x12:  // to be ignored
 757                 case 0x59:  // to be ignored
 758                     state = INIT;
 759                     break;
 760                 case 0xF0:
 761                     state = E0_F0;
 762                     break;
 763                 default:
 764                     state = INIT;
 765                     if (code < 0x80) {
 766                         matrix_make(cs2_e0code(code));
 767                     } else {
 768                         matrix_clear();
 769                         xprintf("!CS2_E0!\n");
 770                         return -1;
 771                     }
 772             }
 773             break;
 774         case F0:    // Break code
 775             switch (code) {
 776                 case 0x83:  // F7
 777                     matrix_break(0x02);
 778                     state = INIT;
 779                     break;
 780                 case 0x84:  // Alt'd PrintScreen
 781                     matrix_break(0x7F);
 782                     state = INIT;
 783                     break;
 784                 default:
 785                     state = INIT;
 786                     if (code < 0x80) {
 787                         matrix_break(code);
 788                     } else {
 789                         matrix_clear();
 790                         xprintf("!CS2_F0!\n");
 791                         return -1;
 792                     }
 793             }
 794             break;
 795         case E0_F0: // Break code of E0-prefixed
 796             switch (code) {
 797                 case 0x12:  // to be ignored
 798                 case 0x59:  // to be ignored
 799                     state = INIT;
 800                     break;
 801                 default:
 802                     state = INIT;
 803                     if (code < 0x80) {
 804                         matrix_break(cs2_e0code(code));
 805                     } else {
 806                         matrix_clear();
 807                         xprintf("!CS2_E0_F0!\n");
 808                         return -1;
 809                     }
 810             }
 811             break;
 812         // Pause make: E1 14 77
 813         case E1:
 814             switch (code) {
 815                 case 0x14:
 816                     state = E1_14;
 817                     break;
 818                 case 0xF0:
 819                     state = E1_F0;
 820                     break;
 821                 default:
 822                     state = INIT;
 823             }
 824             break;
 825         case E1_14:
 826             switch (code) {
 827                 case 0x77:
 828                     matrix_make(0x00);
 829                     state = INIT;
 830                     break;
 831                 default:
 832                     state = INIT;
 833             }
 834             break;
 835         // Pause break: E1 F0 14 F0 77
 836         case E1_F0:
 837             switch (code) {
 838                 case 0x14:
 839                     state = E1_F0_14;
 840                     break;
 841                 default:
 842                     state = INIT;
 843             }
 844             break;
 845         case E1_F0_14:
 846             switch (code) {
 847                 case 0xF0:
 848                     state = E1_F0_14_F0;
 849                     break;
 850                 default:
 851                     state = INIT;
 852             }
 853             break;
 854         case E1_F0_14_F0:
 855             switch (code) {
 856                 case 0x77:
 857                     matrix_break(0x00);
 858                     state = INIT;
 859                     break;
 860                 default:
 861                     state = INIT;
 862             }
 863             break;
 864         default:
 865             state = INIT;
 866     }
 867     return 0;
 868 }
 869
 870 /*
 871  * Terminal: Scan Code Set 3
 872  *
 873  * See [3], [7] and
 874  * https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-AT-Keyboard-Protocol#scan-code-set-3
 875  */
 876 static int8_t process_cs3(void)
 877 {
 878     static enum {
 879         READY,
 880         F0,
 881 #ifdef G80_2551_SUPPORT
 882         // G80-2551 four extra keys around cursor keys
 883         G80,
 884         G80_F0,
 885 #endif
 886     } state = READY;
 887
 888     uint16_t code = ibmpc_host_recv();
 889     if (code == -1) {
 890         return 0;
 891     }
 892
 893     switch (state) {
 894         case READY:
 895             switch (code) {
 896                 case 0x00:  // Error/Overrun [3]p.26
 897                     xprintf("!CS3_OVR!\n");
 898                     matrix_clear();
 899                     clear_keyboard();
 900                     break;
 901                 case 0xFF:
 902                     xprintf("!CS3_ERR!\n");
 903                     return -1;
 904                     break;
 905                 case 0xF0:
 906                     state = F0;
 907                     break;
 908                 case 0x83:  // PrintScreen
 909                     matrix_make(0x02);
 910                     break;
 911                 case 0x84:  // Keypad *
 912                     matrix_make(0x7F);
 913                     break;
 914                 case 0x85:  // Muhenkan
 915                     matrix_make(0x0B);
 916                     break;
 917                 case 0x86:  // Henkan
 918                     matrix_make(0x06);
 919                     break;
 920                 case 0x87:  // Hiragana
 921                     matrix_make(0x00);
 922                     break;
 923                 case 0x8B:  // Left GUI
 924                     matrix_make(0x01);
 925                     break;
 926                 case 0x8C:  // Right GUI
 927                     matrix_make(0x09);
 928                     break;
 929                 case 0x8D:  // Application
 930                     matrix_make(0x0A);
 931                     break;
 932 #ifdef G80_2551_SUPPORT
 933                 case 0x80:  // G80-2551 four extra keys around cursor keys
 934                     state = G80;
 935                     break;
 936 #endif
 937                 default:    // normal key make
 938                     if (code < 0x80) {
 939                         matrix_make(code);
 940                     } else {
 941                         xprintf("!CS3_READY!\n");
 942                         //return -1;
 943                     }
 944             }
 945             break;
 946         case F0:    // Break code
 947             switch (code) {
 948                 case 0x00:
 949                     xprintf("!CS3_F0_OVR!\n");
 950                     matrix_clear();
 951                     clear_keyboard();
 952                     state = READY;
 953                     break;
 954                 case 0xFF:
 955                     xprintf("!CS3_F0_ERR!\n");
 956                     state = READY;
 957                     return -1;
 958                     break;
 959                 case 0x83:  // PrintScreen
 960                     matrix_break(0x02);
 961                     state = READY;
 962                     break;
 963                 case 0x84:  // Keypad *
 964                     matrix_break(0x7F);
 965                     state = READY;
 966                     break;
 967                 case 0x85:  // Muhenkan
 968                     matrix_break(0x0B);
 969                     state = READY;
 970                     break;
 971                 case 0x86:  // Henkan
 972                     matrix_break(0x06);
 973                     state = READY;
 974                     break;
 975                 case 0x87:  // Hiragana
 976                     matrix_break(0x00);
 977                     state = READY;
 978                     break;
 979                 case 0x8B:  // Left GUI
 980                     matrix_break(0x01);
 981                     state = READY;
 982                     break;
 983                 case 0x8C:  // Right GUI
 984                     matrix_break(0x09);
 985                     state = READY;
 986                     break;
 987                 case 0x8D:  // Application
 988                     matrix_break(0x0A);
 989                     state = READY;
 990                     break;
 991                 default:
 992                     state = READY;
 993                     if (code < 0x80) {
 994                         matrix_break(code);
 995                     } else {
 996                         xprintf("!CS3_F0!\n");
 997                         //return -1;
 998                     }
 999             }
1000             break;
1001 #ifdef G80_2551_SUPPORT
1002         /*
1003          * G80-2551 terminal keyboard support
1004          * https://deskthority.net/wiki/Cherry_G80-2551
1005          * https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-AT-Keyboard-Protocol#g80-2551-in-code-set-3
1006          */
1007         case G80:   // G80-2551 four extra keys around cursor keys
1008             switch (code) {
1009                 case (0x26):    // TD= -> JYEN
1010                     matrix_make(0x5D);
1011                     break;
1012                 case (0x25):    // page with edge -> NUHS
1013                     matrix_make(0x53);
1014                     break;
1015                 case (0x16):    // two pages -> RO
1016                     matrix_make(0x51);
1017                     break;
1018                 case (0x1E):    // calc -> KANA
1019                     matrix_make(0x00);
1020                     break;
1021                 case (0xF0):
1022                     state = G80_F0;
1023                     return 0;
1024                 default:
1025                     // Not supported
1026                     matrix_clear();
1027                     break;
1028             }
1029             state = READY;
1030             break;
1031         case G80_F0:
1032             switch (code) {
1033                 case (0x26):    // TD= -> JYEN
1034                     matrix_break(0x5D);
1035                     break;
1036                 case (0x25):    // page with edge -> NUHS
1037                     matrix_break(0x53);
1038                     break;
1039                 case (0x16):    // two pages -> RO
1040                     matrix_break(0x51);
1041                     break;
1042                 case (0x1E):    // calc -> KANA
1043                     matrix_break(0x00);
1044                     break;
1045                 default:
1046                     // Not supported
1047                     matrix_clear();
1048                     break;
1049             }
1050             state = READY;
1051             break;
1052 #endif
1053     }
1054     return 0;
1055 }
1056
1057 /*
1058  * IBM PC Keyboard Protocol Resources:
1059  *
1060  * [a] Microsoft USB HID to PS/2 Translation Table - Scan Code Set 1 and 2
1061  * http://download.microsoft.com/download/1/6/1/161ba512-40e2-4cc9-843a-923143f3456c/translate.pdf
1062  *
1063  * [b] Microsoft Keyboard Scan Code Specification - Special rules of Scan Code Set 1 and 2
1064  * http://download.microsoft.com/download/1/6/1/161ba512-40e2-4cc9-843a-923143f3456c/scancode.doc
1065  *
1066  * [1] PS/2 Reference Manuals - Collection of IBM Personal System/2 documents.
1067  * http://www.mcamafia.de/pdf/pdfref.htm
1068  *
1069  * [2] Keyboard and Auxiliary Device Controller - Signal Timing and Format
1070  * http://www.mcamafia.de/pdf/ibm_hitrc07.pdf
1071  *
1072  * [3] Keyboards(101- and 102-key) - Keyboard Layout, Scan Code Set, POR, and Commands.
1073  * http://www.mcamafia.de/pdf/ibm_hitrc11.pdf
1074  *
1075  * [4] IBM PC XT Keyboard Protocol
1076  * https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-XT-Keyboard-Protocol
1077  *
1078  * [5] IBM Keyboard Scan Code by John Elliott - 83-key, 84-key, 102-key and 122-key
1079  * https://www.seasip.info/VintagePC/index.html
1080  *
1081  * [6] IBM 1391406 Keyboard - Scan Code Set 2 of 102-key PS/2 keyboard
1082  * https://www.seasip.info/VintagePC/ibm_1391406.html
1083  *
1084  * [7] The IBM 6110344 Keyboard - Scan Code Set 3 of 122-key terminal keyboard
1085  * https://www.seasip.info/VintagePC/ibm_6110344.html
1086  *
1087  * [8] IBM PC AT Technical Reference 1986
1088  * http://bitsavers.org/pdf/ibm/pc/at/6183355_PC_AT_Technical_Reference_Mar86.pdf
1089  *
1090  * [y] TrackPoint Engineering Specifications for version 3E
1091  * https://web.archive.org/web/20100526161812/http://wwwcssrv.almaden.ibm.com/trackpoint/download.html
1092  *
1093  * [z] [Soarer's XT/AT/PS2/Terminal to USB converter]
1094  * https://geekhack.org/index.php?topic=17458.0
1095  *
1096  */