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 /*
  87  * Don't call this in a row without the delay, otherwise it makes some of poor controllers
  88  * overloaded and misses strokes. Recommended delay is 16ms.
  89  *
  90  * Thanks a lot, blargg! <http://geekhack.org/index.php?topic=14290.msg1068919#msg1068919>
  91  */
  92 uint16_t adb_host_kbd_recv(void)
  93 {
  94     uint16_t data = 0;
  95     attention();
  96     send_byte(0x2C);            // Addr:Keyboard(0010), Cmd:Talk(11), Register0(00)
  97     place_bit0();               // Stopbit(0)
  98     if (!wait_data_lo(500)) {   // Tlt/Stop to Start(140-260us)
  99         return 0;               // No data to send
 100     }
 101     if (!read_bit()) {          // Startbit(1)
 102         // Service Request
 103         dprintf("Startbit ERROR\n");
 104         return -2;
 105     }
 106
 107     // ad hoc fix: without block inerrupt read wrong bit occasionally and get keys stuck
 108     cli();
 109     data = read_byte();
 110     data = (data<<8) | read_byte();
 111     uint8_t stop = read_bit();  // Stopbit(0)
 112     sei();
 113
 114     if (stop) {
 115         dprintf("Stopbit ERROR\n");
 116         return -3;
 117     }
 118     return data;
 119 }
 120
 121 void adb_host_listen(uint8_t cmd, uint8_t data_h, uint8_t data_l)
 122 {
 123     attention();
 124     send_byte(cmd);
 125     place_bit0();               // Stopbit(0)
 126     _delay_us(200);             // Tlt/Stop to Start
 127     place_bit1();               // Startbit(1)
 128     send_byte(data_h);
 129     send_byte(data_l);
 130     place_bit0();               // Stopbit(0);
 131 }
 132
 133 // send state of LEDs
 134 void adb_host_kbd_led(uint8_t led)
 135 {
 136     // Addr:Keyboard(0010), Cmd:Listen(10), Register2(10)
 137     // send upper byte (not used)
 138     // send lower byte (bit2: ScrollLock, bit1: CapsLock, bit0:
 139     adb_host_listen(0x2A,0,led&0x07);
 140 }
 141
 142
 143 static inline void data_lo()
 144 {
 145     ADB_DDR  |=  (1<<ADB_DATA_BIT);
 146     ADB_PORT &= ~(1<<ADB_DATA_BIT);
 147 }
 148 static inline void data_hi()
 149 {
 150     ADB_PORT |=  (1<<ADB_DATA_BIT);
 151     ADB_DDR  &= ~(1<<ADB_DATA_BIT);
 152 }
 153 static inline bool data_in()
 154 {
 155     ADB_PORT |=  (1<<ADB_DATA_BIT);
 156     ADB_DDR  &= ~(1<<ADB_DATA_BIT);
 157     return ADB_PIN&(1<<ADB_DATA_BIT);
 158 }
 159
 160 #ifdef ADB_PSW_BIT
 161 static inline void psw_lo()
 162 {
 163     ADB_DDR  |=  (1<<ADB_PSW_BIT);
 164     ADB_PORT &= ~(1<<ADB_PSW_BIT);
 165 }
 166 static inline void psw_hi()
 167 {
 168     ADB_PORT |=  (1<<ADB_PSW_BIT);
 169     ADB_DDR  &= ~(1<<ADB_PSW_BIT);
 170 }
 171 static inline bool psw_in()
 172 {
 173     ADB_PORT |=  (1<<ADB_PSW_BIT);
 174     ADB_DDR  &= ~(1<<ADB_PSW_BIT);
 175     return ADB_PIN&(1<<ADB_PSW_BIT);
 176 }
 177 #endif
 178
 179 static inline void attention(void)
 180 {
 181     data_lo();
 182     _delay_us(700);
 183     place_bit1();
 184 }
 185
 186 static inline void place_bit0(void)
 187 {
 188     data_lo();
 189     _delay_us(65);
 190     data_hi();
 191     _delay_us(35);
 192 }
 193
 194 static inline void place_bit1(void)
 195 {
 196     data_lo();
 197     _delay_us(35);
 198     data_hi();
 199     _delay_us(65);
 200 }
 201
 202 static inline void send_byte(uint8_t data)
 203 {
 204     for (int i = 0; i < 8; i++) {
 205         if (data&(0x80>>i))
 206             place_bit1();
 207         else
 208             place_bit0();
 209     }
 210 }
 211
 212 static inline bool read_bit(void)
 213 {
 214     // ADB Bit Cells
 215     //
 216     // bit cell time: 70-130us
 217     // low part of bit0: 60-70% of bit cell
 218     // low part of bit1: 30-40% of bit cell
 219     //
 220     //    bit cell time         70us        130us
 221     //    --------------------------------------------
 222     //    low  part of bit0     42-49       78-91
 223     //    high part of bit0     21-28       39-52
 224     //    low  part of bit1     21-28       39-52
 225     //    high part of bit1     42-49       78-91
 226     //
 227     //
 228     // bit0:
 229     //    70us bit cell:
 230     //      ____________~~~~~~
 231     //      42-49        21-28
 232     //
 233     //    130us bit cell:
 234     //      ____________~~~~~~
 235     //      78-91        39-52
 236     //
 237     // bit1:
 238     //    70us bit cell:
 239     //      ______~~~~~~~~~~~~
 240     //      21-28        42-49
 241     //
 242     //    130us bit cell:
 243     //      ______~~~~~~~~~~~~
 244     //      39-52        78-91
 245     //
 246     // read:
 247     //      ________|~~~~~~~~~
 248     //              55us
 249     // Read data line after 55us. If data line is low/high then bit is 0/1.
 250     // This method might not work at <90us bit cell time.
 251     //
 252     // [from Apple IIgs Hardware Reference Second Edition]
 253     bool bit;
 254     wait_data_lo(75);   // wait the start of bit cell at least 130ms(55+0+75)
 255     _delay_us(55);
 256     bit = data_in();
 257     wait_data_hi(36);   // wait high part of bit cell at least 91ms(55+36)
 258     return bit;
 259 }
 260
 261 static inline uint8_t read_byte(void)
 262 {
 263     uint8_t data = 0;
 264     for (int i = 0; i < 8; i++) {
 265         data <<= 1;
 266         if (read_bit())
 267             data = data | 1;
 268     }
 269     return data;
 270 }
 271
 272 static inline uint8_t wait_data_lo(uint16_t us)
 273 {
 274     while (data_in() && us) {
 275         _delay_us(1);
 276         us--;
 277     }
 278     return us;
 279 }
 280
 281 static inline uint8_t wait_data_hi(uint8_t us)
 282 {
 283     while (!data_in() && us) {
 284         _delay_us(1);
 285         us--;
 286     }
 287     return us;
 288 }
 289
 290
 291 /*
 292 ADB Protocol
 293 ============
 294
 295 Resources
 296 ---------
 297 ADB - The Untold Story: Space Aliens Ate My Mouse
 298     http://developer.apple.com/legacy/mac/library/#technotes/hw/hw_01.html
 299 ADB Manager
 300     http://developer.apple.com/legacy/mac/library/documentation/mac/pdf/Devices/ADB_Manager.pdf
 301     Service request(5-17)
 302 Apple IIgs Hardware Reference Second Edition [Chapter6 p121]
 303     ftp://ftp.apple.asimov.net/pub/apple_II/documentation/Apple%20IIgs%20Hardware%20Reference.pdf
 304 ADB Keycode
 305     http://72.0.193.250/Documentation/macppc/adbkeycodes/
 306     http://m0115.web.fc2.com/m0115.jpg
 307     [Inside Macintosh volume V, pages 191-192]
 308     http://www.opensource.apple.com/source/IOHIDFamily/IOHIDFamily-421.18.3/IOHIDFamily/Cosmo_USB2ADB.c
 309 ADB Signaling
 310     http://kbdbabel.sourceforge.net/doc/kbd_signaling_pcxt_ps2_adb.pdf
 311 ADB Overview & History
 312     http://en.wikipedia.org/wiki/Apple_Desktop_Bus
 313 Microchip Application Note: ADB device(with code for PIC16C)
 314     http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1824&appnote=en011062
 315 AVR ATtiny2131 ADB to PS/2 converter(Japanese)
 316     http://hp.vector.co.jp/authors/VA000177/html/KeyBoardA5DEA5CBA5A2II.html
 317
 318
 319 Pinouts
 320 -------
 321     ADB female socket from the front:
 322     __________
 323     |        | <--- top
 324     | 4o  o3 |
 325     |2o    o1|
 326     |   ==   |
 327     |________| <--- bottom
 328       |    |   <--- 4pins
 329
 330
 331     ADB female socket from bottom:
 332
 333     ========== <--- front
 334     |        |
 335     |        |
 336     |2o    o1|
 337     |4o    o3|
 338     ---------- <--- back
 339
 340     1: Data
 341     2: Power SW(low when press Power key)
 342     3: Vcc(5V)
 343     4: GND
 344
 345
 346 Commands
 347 --------
 348     ADB command is 1byte and consists of 4bit-address, 2bit-command
 349     type and 2bit-register. The commands are always sent by Host.
 350
 351     Command format:
 352     7 6 5 4 3 2 1 0
 353     | | | |------------ address
 354             | |-------- command type
 355                 | |---- register
 356
 357     bits                commands
 358     ------------------------------------------------------
 359     - - - - 0 0 0 0     Send Request(reset all devices)
 360     A A A A 0 0 0 1     Flush(reset a device)
 361     - - - - 0 0 1 0     Reserved
 362     - - - - 0 0 1 1     Reserved
 363     - - - - 0 1 - -     Reserved
 364     A A A A 1 0 R R     Listen(write to a device)
 365     A A A A 1 1 R R     Talk(read from a device)
 366
 367     The command to read keycodes from keyboard is 0x2C which
 368     consist of keyboard address 2 and Talk against register 0.
 369
 370     Address:
 371     2:  keyboard
 372     3:  mice
 373
 374     Registers:
 375     0: application(keyobard uses this to store its data.)
 376     1: application
 377     2: application(keyboard uses this for LEDs and state of modifiers)
 378     3: status and command
 379
 380
 381 Communication
 382 -------------
 383     This is a minimum information for keyboard communication.
 384     See "Resources" for detail.
 385
 386     Signaling:
 387
 388     ~~~~____________~~||||||||||||__~~~~~_~~|||||||||||||||__~~~~
 389
 390         |800us     |  |7 Command 0|  |   |  |15-64  Data  0|Stopbit(0)
 391         +Attention |              |  |   +Startbit(1)
 392                    +Startbit(1)   |  +Tlt(140-260us)
 393                                   +stopbit(0)
 394
 395     Bit cells:
 396
 397     bit0: ______~~~
 398           65    :35us
 399
 400     bit1: ___~~~~~~
 401           35 :65us
 402
 403     bit0 low time: 60-70% of bit cell(42-91us)
 404     bit1 low time: 30-40% of bit cell(21-52us)
 405     bit cell time: 70-130us
 406     [from Apple IIgs Hardware Reference Second Edition]
 407
 408     Criterion for bit0/1:
 409     After 55us if line is low/high then bit is 0/1.
 410
 411     Attention & start bit:
 412     Host asserts low in 560-1040us then places start bit(1).
 413
 414     Tlt(Stop to Start):
 415     Bus stays high in 140-260us then device places start bit(1).
 416
 417     Global reset:
 418     Host asserts low in 2.8-5.2ms. All devices are forced to reset.
 419
 420     Service request from device(Srq):
 421     Device can request to send at commad(Global only?) stop bit.
 422     Requesting device keeps low for 140-260us at stop bit of command.
 423
 424
 425 Keyboard Data(Register0)
 426     This 16bit data can contains two keycodes and two released flags.
 427     First keycode is palced in upper byte. When one keyocode is sent,
 428     lower byte is 0xFF.
 429     Release flag is 1 when key is released.
 430
 431     1514 . . . . . 8 7 6 . . . . . 0
 432      | | | | | | | | | +-+-+-+-+-+-+-   Keycode2
 433      | | | | | | | | +---------------   Released2(1 when the key is released)
 434      | +-+-+-+-+-+-+-----------------   Keycode1
 435      +-------------------------------   Released1(1 when the key is released)
 436
 437     Keycodes:
 438     Scancode consists of 7bit keycode and 1bit release flag.
 439     Device can send two keycodes at once. If just one keycode is sent
 440     keycode1 contains it and keyocode2 is 0xFF.
 441
 442     Power switch:
 443     You can read the state from PSW line(active low) however
 444     the switch has a special scancode 0x7F7F, so you can
 445     also read from Data line. It uses 0xFFFF for release scancode.
 446
 447 Keyboard LEDs & state of keys(Register2)
 448     This register hold current state of three LEDs and nine keys.
 449     The state of LEDs can be changed by sending Listen command.
 450
 451     1514 . . . . . . 7 6 5 . 3 2 1 0
 452      | | | | | | | | | | | | | | | +-   LED1(NumLock)
 453      | | | | | | | | | | | | | | +---   LED2(CapsLock)
 454      | | | | | | | | | | | | | +-----   LED3(ScrollLock)
 455      | | | | | | | | | | +-+-+-------   Reserved
 456      | | | | | | | | | +-------------   ScrollLock
 457      | | | | | | | | +---------------   NumLock
 458      | | | | | | | +-----------------   Apple/Command
 459      | | | | | | +-------------------   Option
 460      | | | | | +---------------------   Shift
 461      | | | | +-----------------------   Control
 462      | | | +-------------------------   Reset/Power
 463      | | +---------------------------   CapsLock
 464      | +-----------------------------   Delete
 465      +-------------------------------   Reserved
 466
 467 END_OF_ADB
 468 */