protocol/adb.c

   1 /*
   2 Copyright 2011 Jun WAKO <wakojun@gmail.com>
   3
   4 This software is licensed with a Modified BSD License.
   5 All of this is supposed to be Free Software, Open Source, DFSG-free,
   6 GPL-compatible, and OK to use in both free and proprietary applications.
   7 Additions and corrections to this file are welcome.
   8
   9
  10 Redistribution and use in source and binary forms, with or without
  11 modification, are permitted provided that the following conditions are met:
  12
  13 * Redistributions of source code must retain the above copyright
  14   notice, this list of conditions and the following disclaimer.
  15
  16 * Redistributions in binary form must reproduce the above copyright
  17   notice, this list of conditions and the following disclaimer in
  18   the documentation and/or other materials provided with the
  19   distribution.
  20
  21 * Neither the name of the copyright holders nor the names of
  22   contributors may be used to endorse or promote products derived
  23   from this software without specific prior written permission.
  24
  25 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  26 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  27 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  28 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  29 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  32 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  33 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  34 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  35 POSSIBILITY OF SUCH DAMAGE.
  36 */
  37
  38 #include <stdbool.h>
  39 #include <util/delay.h>
  40 #include <avr/io.h>
  41 #include <avr/interrupt.h>
  42 #include "adb.h"
  43 #include "debug.h"
  44
  45
  46 static inline void data_lo(void);
  47 static inline void data_hi(void);
  48 static inline bool data_in(void);
  49 #ifdef ADB_PSW_BIT
  50 static inline void psw_lo(void);
  51 static inline void psw_hi(void);
  52 static inline bool psw_in(void);
  53 #endif
  54
  55 static inline void attention(void);
  56 static inline void place_bit0(void);
  57 static inline void place_bit1(void);
  58 static inline void send_byte(uint8_t data);
  59 static inline bool read_bit(void);
  60 static inline uint8_t read_byte(void);
  61 static inline uint8_t wait_data_lo(uint16_t us);
  62 static inline uint8_t wait_data_hi(uint8_t us);
  63
  64
  65 void adb_host_init(void)
  66 {
  67     data_hi();
  68 #ifdef ADB_PSW_BIT
  69     psw_hi();
  70 #endif
  71
  72     // Enable keyboard left/right modifier distinction
  73     // Addr:Keyboard(0010), Cmd:Listen(10), Register3(11)
  74     // upper byte: reserved bits 0000, device address 0010
  75     // lower byte: device handler 00000011
  76     adb_host_listen(0x2B,0x02,0x03);
  77 }
  78
  79 #ifdef ADB_PSW_BIT
  80 bool adb_host_psw(void)
  81 {
  82     return psw_in();
  83 }
  84 #endif
  85
  86 uint16_t adb_host_kbd_recv(void)
  87 {
  88     uint16_t data = 0;
  89     attention();
  90     send_byte(0x2C);            // Addr:Keyboard(0010), Cmd:Talk(11), Register0(00)
  91     place_bit0();               // Stopbit(0)
  92     if (!wait_data_lo(500)) {   // Tlt/Stop to Start(140-260us)
  93         return 0;               // No data to send
  94     }
  95     if (!read_bit()) {          // Startbit(1)
  96         // Service Request
  97         dprintf("Startbit ERROR\n");
  98         return -2;
  99     }
 100
 101     // ad hoc fix: without block inerrupt read wrong bit occasionally and get keys stuck
 102     cli();
 103     data = read_byte();
 104     data = (data<<8) | read_byte();
 105     uint8_t stop = read_bit();  // Stopbit(0)
 106     sei();
 107
 108     if (stop) {
 109         dprintf("Stopbit ERROR\n");
 110         return -3;
 111     }
 112     return data;
 113 }
 114
 115 void adb_host_listen(uint8_t cmd, uint8_t data_h, uint8_t data_l)
 116 {
 117     attention();
 118     send_byte(cmd);
 119     place_bit0();               // Stopbit(0)
 120     _delay_us(200);             // Tlt/Stop to Start
 121     place_bit1();               // Startbit(1)
 122     send_byte(data_h);
 123     send_byte(data_l);
 124     place_bit0();               // Stopbit(0);
 125 }
 126
 127 // send state of LEDs
 128 void adb_host_kbd_led(uint8_t led)
 129 {
 130     // Addr:Keyboard(0010), Cmd:Listen(10), Register2(10)
 131     // send upper byte (not used)
 132     // send lower byte (bit2: ScrollLock, bit1: CapsLock, bit0:
 133     adb_host_listen(0x2A,0,led&0x07);
 134 }
 135
 136
 137 static inline void data_lo()
 138 {
 139     ADB_DDR  |=  (1<<ADB_DATA_BIT);
 140     ADB_PORT &= ~(1<<ADB_DATA_BIT);
 141 }
 142 static inline void data_hi()
 143 {
 144     ADB_PORT |=  (1<<ADB_DATA_BIT);
 145     ADB_DDR  &= ~(1<<ADB_DATA_BIT);
 146 }
 147 static inline bool data_in()
 148 {
 149     ADB_PORT |=  (1<<ADB_DATA_BIT);
 150     ADB_DDR  &= ~(1<<ADB_DATA_BIT);
 151     return ADB_PIN&(1<<ADB_DATA_BIT);
 152 }
 153
 154 #ifdef ADB_PSW_BIT
 155 static inline void psw_lo()
 156 {
 157     ADB_DDR  |=  (1<<ADB_PSW_BIT);
 158     ADB_PORT &= ~(1<<ADB_PSW_BIT);
 159 }
 160 static inline void psw_hi()
 161 {
 162     ADB_PORT |=  (1<<ADB_PSW_BIT);
 163     ADB_DDR  &= ~(1<<ADB_PSW_BIT);
 164 }
 165 static inline bool psw_in()
 166 {
 167     ADB_PORT |=  (1<<ADB_PSW_BIT);
 168     ADB_DDR  &= ~(1<<ADB_PSW_BIT);
 169     return ADB_PIN&(1<<ADB_PSW_BIT);
 170 }
 171 #endif
 172
 173 static inline void attention(void)
 174 {
 175     data_lo();
 176     _delay_us(700);
 177     place_bit1();
 178 }
 179
 180 static inline void place_bit0(void)
 181 {
 182     data_lo();
 183     _delay_us(65);
 184     data_hi();
 185     _delay_us(35);
 186 }
 187
 188 static inline void place_bit1(void)
 189 {
 190     data_lo();
 191     _delay_us(35);
 192     data_hi();
 193     _delay_us(65);
 194 }
 195
 196 static inline void send_byte(uint8_t data)
 197 {
 198     for (int i = 0; i < 8; i++) {
 199         if (data&(0x80>>i))
 200             place_bit1();
 201         else
 202             place_bit0();
 203     }
 204 }
 205
 206 static inline bool read_bit(void)
 207 {
 208     // ADB Bit Cells
 209     //
 210     // bit cell time: 70-130us
 211     // low part of bit0: 60-70% of bit cell
 212     // low part of bit1: 30-40% of bit cell
 213     //
 214     //    bit cell time         70us        130us
 215     //    --------------------------------------------
 216     //    low  part of bit0     42-49       78-91
 217     //    high part of bit0     21-28       39-52
 218     //    low  part of bit1     21-28       39-52
 219     //    high part of bit1     42-49       78-91
 220     //
 221     //
 222     // bit0:
 223     //    70us bit cell:
 224     //      ____________~~~~~~
 225     //      42-49        21-28
 226     //
 227     //    130us bit cell:
 228     //      ____________~~~~~~
 229     //      78-91        39-52
 230     //
 231     // bit1:
 232     //    70us bit cell:
 233     //      ______~~~~~~~~~~~~
 234     //      21-28        42-49
 235     //
 236     //    130us bit cell:
 237     //      ______~~~~~~~~~~~~
 238     //      39-52        78-91
 239     //
 240     // read:
 241     //      ________|~~~~~~~~~
 242     //              55us
 243     // Read data line after 55us. If data line is low/high then bit is 0/1.
 244     // This method might not work at <90us bit cell time.
 245     //
 246     // [from Apple IIgs Hardware Reference Second Edition]
 247     bool bit;
 248     wait_data_lo(75);   // wait the start of bit cell at least 130ms(55+0+75)
 249     _delay_us(55);
 250     bit = data_in();
 251     wait_data_hi(36);   // wait high part of bit cell at least 91ms(55+36)
 252     return bit;
 253 }
 254
 255 static inline uint8_t read_byte(void)
 256 {
 257     uint8_t data = 0;
 258     for (int i = 0; i < 8; i++) {
 259         data <<= 1;
 260         if (read_bit())
 261             data = data | 1;
 262     }
 263     return data;
 264 }
 265
 266 static inline uint8_t wait_data_lo(uint16_t us)
 267 {
 268     while (data_in() && us) {
 269         _delay_us(1);
 270         us--;
 271     }
 272     return us;
 273 }
 274
 275 static inline uint8_t wait_data_hi(uint8_t us)
 276 {
 277     while (!data_in() && us) {
 278         _delay_us(1);
 279         us--;
 280     }
 281     return us;
 282 }
 283
 284
 285 /*
 286 ADB Protocol
 287 ============
 288
 289 Resources
 290 ---------
 291 ADB - The Untold Story: Space Aliens Ate My Mouse
 292     http://developer.apple.com/legacy/mac/library/#technotes/hw/hw_01.html
 293 ADB Manager
 294     http://developer.apple.com/legacy/mac/library/documentation/mac/pdf/Devices/ADB_Manager.pdf
 295     Service request(5-17)
 296 Apple IIgs Hardware Reference Second Edition [Chapter6 p121]
 297     ftp://ftp.apple.asimov.net/pub/apple_II/documentation/Apple%20IIgs%20Hardware%20Reference.pdf
 298 ADB Keycode
 299     http://72.0.193.250/Documentation/macppc/adbkeycodes/
 300     http://m0115.web.fc2.com/m0115.jpg
 301     [Inside Macintosh volume V, pages 191-192]
 302     http://www.opensource.apple.com/source/IOHIDFamily/IOHIDFamily-421.18.3/IOHIDFamily/Cosmo_USB2ADB.c
 303 ADB Signaling
 304     http://kbdbabel.sourceforge.net/doc/kbd_signaling_pcxt_ps2_adb.pdf
 305 ADB Overview & History
 306     http://en.wikipedia.org/wiki/Apple_Desktop_Bus
 307 Microchip Application Note: ADB device(with code for PIC16C)
 308     http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1824&appnote=en011062
 309 AVR ATtiny2131 ADB to PS/2 converter(Japanese)
 310     http://hp.vector.co.jp/authors/VA000177/html/KeyBoardA5DEA5CBA5A2II.html
 311
 312
 313 Pinouts
 314 -------
 315     ADB female socket from the front:
 316     __________
 317     |        | <--- top
 318     | 4o  o3 |
 319     |2o    o1|
 320     |   ==   |
 321     |________| <--- bottom
 322       |    |   <--- 4pins
 323
 324
 325     ADB female socket from bottom:
 326
 327     ========== <--- front
 328     |        |
 329     |        |
 330     |2o    o1|
 331     |4o    o3|
 332     ---------- <--- back
 333
 334     1: Data
 335     2: Power SW(low when press Power key)
 336     3: Vcc(5V)
 337     4: GND
 338
 339
 340 Commands
 341 --------
 342     ADB command is 1byte and consists of 4bit-address, 2bit-command
 343     type and 2bit-register. The commands are always sent by Host.
 344
 345     Command format:
 346     7 6 5 4 3 2 1 0
 347     | | | |------------ address
 348             | |-------- command type
 349                 | |---- register
 350
 351     bits                commands
 352     ------------------------------------------------------
 353     - - - - 0 0 0 0     Send Request(reset all devices)
 354     A A A A 0 0 0 1     Flush(reset a device)
 355     - - - - 0 0 1 0     Reserved
 356     - - - - 0 0 1 1     Reserved
 357     - - - - 0 1 - -     Reserved
 358     A A A A 1 0 R R     Listen(write to a device)
 359     A A A A 1 1 R R     Talk(read from a device)
 360
 361     The command to read keycodes from keyboard is 0x2C which
 362     consist of keyboard address 2 and Talk against register 0.
 363
 364     Address:
 365     2:  keyboard
 366     3:  mice
 367
 368     Registers:
 369     0: application(keyobard uses this to store its data.)
 370     1: application
 371     2: application(keyboard uses this for LEDs and state of modifiers)
 372     3: status and command
 373
 374
 375 Communication
 376 -------------
 377     This is a minimum information for keyboard communication.
 378     See "Resources" for detail.
 379
 380     Signaling:
 381
 382     ~~~~____________~~||||||||||||__~~~~~_~~|||||||||||||||__~~~~
 383
 384         |800us     |  |7 Command 0|  |   |  |15-64  Data  0|Stopbit(0)
 385         +Attention |              |  |   +Startbit(1)
 386                    +Startbit(1)   |  +Tlt(140-260us)
 387                                   +stopbit(0)
 388
 389     Bit cells:
 390
 391     bit0: ______~~~
 392           65    :35us
 393
 394     bit1: ___~~~~~~
 395           35 :65us
 396
 397     bit0 low time: 60-70% of bit cell(42-91us)
 398     bit1 low time: 30-40% of bit cell(21-52us)
 399     bit cell time: 70-130us
 400     [from Apple IIgs Hardware Reference Second Edition]
 401
 402     Criterion for bit0/1:
 403     After 55us if line is low/high then bit is 0/1.
 404
 405     Attention & start bit:
 406     Host asserts low in 560-1040us then places start bit(1).
 407
 408     Tlt(Stop to Start):
 409     Bus stays high in 140-260us then device places start bit(1).
 410
 411     Global reset:
 412     Host asserts low in 2.8-5.2ms. All devices are forced to reset.
 413
 414     Service request from device(Srq):
 415     Device can request to send at commad(Global only?) stop bit.
 416     Requesting device keeps low for 140-260us at stop bit of command.
 417
 418
 419 Keyboard Data(Register0)
 420     This 16bit data can contains two keycodes and two released flags.
 421     First keycode is palced in upper byte. When one keyocode is sent,
 422     lower byte is 0xFF.
 423     Release flag is 1 when key is released.
 424
 425     1514 . . . . . 8 7 6 . . . . . 0
 426      | | | | | | | | | +-+-+-+-+-+-+-   Keycode2
 427      | | | | | | | | +---------------   Released2(1 when the key is released)
 428      | +-+-+-+-+-+-+-----------------   Keycode1
 429      +-------------------------------   Released1(1 when the key is released)
 430
 431     Keycodes:
 432     Scancode consists of 7bit keycode and 1bit release flag.
 433     Device can send two keycodes at once. If just one keycode is sent
 434     keycode1 contains it and keyocode2 is 0xFF.
 435
 436     Power switch:
 437     You can read the state from PSW line(active low) however
 438     the switch has a special scancode 0x7F7F, so you can
 439     also read from Data line. It uses 0xFFFF for release scancode.
 440
 441 Keyboard LEDs & state of keys(Register2)
 442     This register hold current state of three LEDs and nine keys.
 443     The state of LEDs can be changed by sending Listen command.
 444
 445     1514 . . . . . . 7 6 5 . 3 2 1 0
 446      | | | | | | | | | | | | | | | +-   LED1(NumLock)
 447      | | | | | | | | | | | | | | +---   LED2(CapsLock)
 448      | | | | | | | | | | | | | +-----   LED3(ScrollLock)
 449      | | | | | | | | | | +-+-+-------   Reserved
 450      | | | | | | | | | +-------------   ScrollLock
 451      | | | | | | | | +---------------   NumLock
 452      | | | | | | | +-----------------   Apple/Command
 453      | | | | | | +-------------------   Option
 454      | | | | | +---------------------   Shift
 455      | | | | +-----------------------   Control
 456      | | | +-------------------------   Reset/Power
 457      | | +---------------------------   CapsLock
 458      | +-----------------------------   Delete
 459      +-------------------------------   Reserved
 460
 461 END_OF_ADB
 462 */