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
  44
  45 static inline void data_lo(void);
  46 static inline void data_hi(void);
  47 static inline bool data_in(void);
  48 #ifdef ADB_PSW_BIT
  49 static inline void psw_lo(void);
  50 static inline void psw_hi(void);
  51 static inline bool psw_in(void);
  52 #endif
  53
  54 static inline void attention(void);
  55 static inline void place_bit0(void);
  56 static inline void place_bit1(void);
  57 static inline void send_byte(uint8_t data);
  58 static inline bool read_bit(void);
  59 static inline uint8_t read_byte(void);
  60 static inline uint8_t wait_data_lo(uint16_t us);
  61 static inline uint8_t wait_data_hi(uint8_t us);
  62
  63
  64 void adb_host_init(void)
  65 {
  66 DDRF |= (1<<1);
  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         return -2;
  98     }
  99
 100     // ad hoc fix: without block inerrupt read wrong bit occasionally and get keys stuck
 101     cli();
 102     data = read_byte();
 103     data = (data<<8) | read_byte();
 104     uint8_t stop = read_bit();  // Stopbit(0)
 105     sei();
 106
 107     if (stop) {
 108         return -3;
 109     }
 110     return data;
 111 }
 112
 113 void adb_host_listen(uint8_t cmd, uint8_t data_h, uint8_t data_l)
 114 {
 115     attention();
 116     send_byte(cmd);
 117     place_bit0();               // Stopbit(0)
 118     _delay_us(200);             // Tlt/Stop to Start
 119     place_bit1();               // Startbit(1)
 120     send_byte(data_h);
 121     send_byte(data_l);
 122     place_bit0();               // Stopbit(0);
 123 }
 124
 125 // send state of LEDs
 126 void adb_host_kbd_led(uint8_t led)
 127 {
 128     // Addr:Keyboard(0010), Cmd:Listen(10), Register2(10)
 129     // send upper byte (not used)
 130     // send lower byte (bit2: ScrollLock, bit1: CapsLock, bit0:
 131     adb_host_listen(0x2A,0,led&0x07);
 132 }
 133
 134
 135 static inline void data_lo()
 136 {
 137     ADB_DDR  |=  (1<<ADB_DATA_BIT);
 138     ADB_PORT &= ~(1<<ADB_DATA_BIT);
 139 }
 140 static inline void data_hi()
 141 {
 142     ADB_PORT |=  (1<<ADB_DATA_BIT);
 143     ADB_DDR  &= ~(1<<ADB_DATA_BIT);
 144 }
 145 static inline bool data_in()
 146 {
 147     ADB_PORT |=  (1<<ADB_DATA_BIT);
 148     ADB_DDR  &= ~(1<<ADB_DATA_BIT);
 149     return ADB_PIN&(1<<ADB_DATA_BIT);
 150 }
 151
 152 #ifdef ADB_PSW_BIT
 153 static inline void psw_lo()
 154 {
 155     ADB_DDR  |=  (1<<ADB_PSW_BIT);
 156     ADB_PORT &= ~(1<<ADB_PSW_BIT);
 157 }
 158 static inline void psw_hi()
 159 {
 160     ADB_PORT |=  (1<<ADB_PSW_BIT);
 161     ADB_DDR  &= ~(1<<ADB_PSW_BIT);
 162 }
 163 static inline bool psw_in()
 164 {
 165     ADB_PORT |=  (1<<ADB_PSW_BIT);
 166     ADB_DDR  &= ~(1<<ADB_PSW_BIT);
 167     return ADB_PIN&(1<<ADB_PSW_BIT);
 168 }
 169 #endif
 170
 171 static inline void attention(void)
 172 {
 173     data_lo();
 174     _delay_us(700);
 175     place_bit1();
 176 }
 177
 178 static inline void place_bit0(void)
 179 {
 180     data_lo();
 181     _delay_us(65);
 182     data_hi();
 183     _delay_us(35);
 184 }
 185
 186 static inline void place_bit1(void)
 187 {
 188     data_lo();
 189     _delay_us(35);
 190     data_hi();
 191     _delay_us(65);
 192 }
 193
 194 static inline void send_byte(uint8_t data)
 195 {
 196     for (int i = 0; i < 8; i++) {
 197         if (data&(0x80>>i))
 198             place_bit1();
 199         else
 200             place_bit0();
 201     }
 202 }
 203
 204 static inline bool read_bit(void)
 205 {
 206     // ADB Bit Cells
 207     //
 208     // bit cell time: 70-130us
 209     // low part of bit0: 60-70% of bit cell
 210     // low part of bit1: 30-40% of bit cell
 211     //
 212     //    bit cell time         70us        130us
 213     //    --------------------------------------------
 214     //    low  part of bit0     42-49       78-91
 215     //    high part of bit0     21-28       39-52
 216     //    low  part of bit1     21-28       39-52
 217     //    high part of bit1     42-49       78-91
 218     //
 219     //
 220     // bit0:
 221     //    70us bit cell:
 222     //      ____________~~~~~~
 223     //      42-49        21-28
 224     //
 225     //    130us bit cell:
 226     //      ____________~~~~~~
 227     //      78-91        39-52
 228     //
 229     // bit1:
 230     //    70us bit cell:
 231     //      ______~~~~~~~~~~~~
 232     //      21-28        42-49
 233     //
 234     //    130us bit cell:
 235     //      ______~~~~~~~~~~~~
 236     //      39-52        78-91
 237     //
 238     // read:
 239     //      ________|~~~~~~~~~
 240     //              55us
 241     // Read data line after 55us. If data line is low/high then bit is 0/1.
 242     // This method might not work at <90us bit cell time.
 243     //
 244     // [from Apple IIgs Hardware Reference Second Edition]
 245     bool bit;
 246     wait_data_lo(75);   // wait the start of bit cell at least 130ms(55+0+75)
 247     _delay_us(55);
 248     bit = data_in();
 249     wait_data_hi(36);   // wait high part of bit cell at least 91ms(55+36)
 250     return bit;
 251 }
 252
 253 static inline uint8_t read_byte(void)
 254 {
 255     uint8_t data = 0;
 256     for (int i = 0; i < 8; i++) {
 257         data <<= 1;
 258         if (read_bit())
 259             data = data | 1;
 260     }
 261     return data;
 262 }
 263
 264 static inline uint8_t wait_data_lo(uint16_t us)
 265 {
 266     while (data_in() && us) {
 267         _delay_us(1);
 268         us--;
 269     }
 270     return us;
 271 }
 272
 273 static inline uint8_t wait_data_hi(uint8_t us)
 274 {
 275     while (!data_in() && us) {
 276         _delay_us(1);
 277         us--;
 278     }
 279     return us;
 280 }
 281
 282
 283 /*
 284 ADB Protocol
 285 ============
 286
 287 Resources
 288 ---------
 289 ADB - The Untold Story: Space Aliens Ate My Mouse
 290     http://developer.apple.com/legacy/mac/library/#technotes/hw/hw_01.html
 291 ADB Manager
 292     http://developer.apple.com/legacy/mac/library/documentation/mac/pdf/Devices/ADB_Manager.pdf
 293     Service request(5-17)
 294 Apple IIgs Hardware Reference Second Edition [Chapter6 p121]
 295     ftp://ftp.apple.asimov.net/pub/apple_II/documentation/Apple%20IIgs%20Hardware%20Reference.pdf
 296 ADB Keycode
 297     http://72.0.193.250/Documentation/macppc/adbkeycodes/
 298     http://m0115.web.fc2.com/m0115.jpg
 299     [Inside Macintosh volume V, pages 191-192]
 300     http://www.opensource.apple.com/source/IOHIDFamily/IOHIDFamily-421.18.3/IOHIDFamily/Cosmo_USB2ADB.c
 301 ADB Signaling
 302     http://kbdbabel.sourceforge.net/doc/kbd_signaling_pcxt_ps2_adb.pdf
 303 ADB Overview & History
 304     http://en.wikipedia.org/wiki/Apple_Desktop_Bus
 305 Microchip Application Note: ADB device(with code for PIC16C)
 306     http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1824&appnote=en011062
 307 AVR ATtiny2131 ADB to PS/2 converter(Japanese)
 308     http://hp.vector.co.jp/authors/VA000177/html/KeyBoardA5DEA5CBA5A2II.html
 309
 310
 311 Pinouts
 312 -------
 313     ADB female socket from the front:
 314     __________
 315     |        | <--- top
 316     | 4o  o3 |
 317     |2o    o1|
 318     |   ==   |
 319     |________| <--- bottom
 320       |    |   <--- 4pins
 321
 322
 323     ADB female socket from bottom:
 324
 325     ========== <--- front
 326     |        |
 327     |        |
 328     |2o    o1|
 329     |4o    o3|
 330     ---------- <--- back
 331
 332     1: Data
 333     2: Power SW(low when press Power key)
 334     3: Vcc(5V)
 335     4: GND
 336
 337
 338 Commands
 339 --------
 340     ADB command is 1byte and consists of 4bit-address, 2bit-command
 341     type and 2bit-register. The commands are always sent by Host.
 342
 343     Command format:
 344     7 6 5 4 3 2 1 0
 345     | | | |------------ address
 346             | |-------- command type
 347                 | |---- register
 348
 349     bits                commands
 350     ------------------------------------------------------
 351     - - - - 0 0 0 0     Send Request(reset all devices)
 352     A A A A 0 0 0 1     Flush(reset a device)
 353     - - - - 0 0 1 0     Reserved
 354     - - - - 0 0 1 1     Reserved
 355     - - - - 0 1 - -     Reserved
 356     A A A A 1 0 R R     Listen(write to a device)
 357     A A A A 1 1 R R     Talk(read from a device)
 358
 359     The command to read keycodes from keyboard is 0x2C which
 360     consist of keyboard address 2 and Talk against register 0.
 361
 362     Address:
 363     2:  keyboard
 364     3:  mice
 365
 366     Registers:
 367     0: application(keyobard uses this to store its data.)
 368     1: application
 369     2: application(keyboard uses this for LEDs and state of modifiers)
 370     3: status and command
 371
 372
 373 Communication
 374 -------------
 375     This is a minimum information for keyboard communication.
 376     See "Resources" for detail.
 377
 378     Signaling:
 379
 380     ~~~~____________~~||||||||||||__~~~~~_~~|||||||||||||||__~~~~
 381
 382         |800us     |  |7 Command 0|  |   |  |15-64  Data  0|Stopbit(0)
 383         +Attention |              |  |   +Startbit(1)
 384                    +Startbit(1)   |  +Tlt(140-260us)
 385                                   +stopbit(0)
 386
 387     Bit cells:
 388
 389     bit0: ______~~~
 390           65    :35us
 391
 392     bit1: ___~~~~~~
 393           35 :65us
 394
 395     bit0 low time: 60-70% of bit cell(42-91us)
 396     bit1 low time: 30-40% of bit cell(21-52us)
 397     bit cell time: 70-130us
 398     [from Apple IIgs Hardware Reference Second Edition]
 399
 400     Criterion for bit0/1:
 401     After 55us if line is low/high then bit is 0/1.
 402
 403     Attention & start bit:
 404     Host asserts low in 560-1040us then places start bit(1).
 405
 406     Tlt(Stop to Start):
 407     Bus stays high in 140-260us then device places start bit(1).
 408
 409     Global reset:
 410     Host asserts low in 2.8-5.2ms. All devices are forced to reset.
 411
 412     Service request from device(Srq):
 413     Device can request to send at commad(Global only?) stop bit.
 414     Requesting device keeps low for 140-260us at stop bit of command.
 415
 416
 417 Keyboard Data(Register0)
 418     This 16bit data can contains two keycodes and two released flags.
 419     First keycode is palced in upper byte. When one keyocode is sent,
 420     lower byte is 0xFF.
 421     Release flag is 1 when key is released.
 422
 423     1514 . . . . . 8 7 6 . . . . . 0
 424      | | | | | | | | | +-+-+-+-+-+-+-   Keycode2
 425      | | | | | | | | +---------------   Released2(1 when the key is released)
 426      | +-+-+-+-+-+-+-----------------   Keycode1
 427      +-------------------------------   Released1(1 when the key is released)
 428
 429     Keycodes:
 430     Scancode consists of 7bit keycode and 1bit release flag.
 431     Device can send two keycodes at once. If just one keycode is sent
 432     keycode1 contains it and keyocode2 is 0xFF.
 433
 434     Power switch:
 435     You can read the state from PSW line(active low) however
 436     the switch has a special scancode 0x7F7F, so you can
 437     also read from Data line. It uses 0xFFFF for release scancode.
 438
 439 Keyboard LEDs & state of keys(Register2)
 440     This register hold current state of three LEDs and nine keys.
 441     The state of LEDs can be changed by sending Listen command.
 442
 443     1514 . . . . . . 7 6 5 . 3 2 1 0
 444      | | | | | | | | | | | | | | | +-   LED1(NumLock)
 445      | | | | | | | | | | | | | | +---   LED2(CapsLock)
 446      | | | | | | | | | | | | | +-----   LED3(ScrollLock)
 447      | | | | | | | | | | +-+-+-------   Reserved
 448      | | | | | | | | | +-------------   ScrollLock
 449      | | | | | | | | +---------------   NumLock
 450      | | | | | | | +-----------------   Apple/Command
 451      | | | | | | +-------------------   Option
 452      | | | | | +---------------------   Shift
 453      | | | | +-----------------------   Control
 454      | | | +-------------------------   Reset/Power
 455      | | +---------------------------   CapsLock
 456      | +-----------------------------   Delete
 457      +-------------------------------   Reserved
 458
 459 END_OF_ADB
 460 */