protocol/adb.c

   1 /*
   2 Copyright 2011 Jun WAKO <wakojun@gmail.com>
   3 Copyright 2013 Shay Green <gblargg@gmail.com>
   4
   5 This software is licensed with a Modified BSD License.
   6 All of this is supposed to be Free Software, Open Source, DFSG-free,
   7 GPL-compatible, and OK to use in both free and proprietary applications.
   8 Additions and corrections to this file are welcome.
   9
  10
  11 Redistribution and use in source and binary forms, with or without
  12 modification, are permitted provided that the following conditions are met:
  13
  14 * Redistributions of source code must retain the above copyright
  15   notice, this list of conditions and the following disclaimer.
  16
  17 * Redistributions in binary form must reproduce the above copyright
  18   notice, this list of conditions and the following disclaimer in
  19   the documentation and/or other materials provided with the
  20   distribution.
  21
  22 * Neither the name of the copyright holders nor the names of
  23   contributors may be used to endorse or promote products derived
  24   from this software without specific prior written permission.
  25
  26 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  27 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  30 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  31 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  32 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  33 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  34 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  35 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  36 POSSIBILITY OF SUCH DAMAGE.
  37 */
  38
  39 #include <stdbool.h>
  40 #include <util/delay.h>
  41 #include <avr/io.h>
  42 #include <avr/interrupt.h>
  43 #include "adb.h"
  44
  45
  46 // GCC doesn't inline functions normally
  47 #define data_lo() (ADB_DDR |=  (1<<ADB_DATA_BIT))
  48 #define data_hi() (ADB_DDR &= ~(1<<ADB_DATA_BIT))
  49 #define data_in() (ADB_PIN &   (1<<ADB_DATA_BIT))
  50
  51 #ifdef ADB_PSW_BIT
  52 static inline void psw_lo(void);
  53 static inline void psw_hi(void);
  54 static inline bool psw_in(void);
  55 #endif
  56
  57 static inline void attention(void);
  58 static inline void place_bit0(void);
  59 static inline void place_bit1(void);
  60 static inline void send_byte(uint8_t data);
  61 static inline uint16_t wait_data_lo(uint16_t us);
  62 static inline uint16_t wait_data_hi(uint16_t us);
  63 static inline uint16_t adb_host_dev_recv(uint8_t device);
  64
  65
  66 void adb_host_init(void)
  67 {
  68     ADB_PORT &= ~(1<<ADB_DATA_BIT);
  69     data_hi();
  70 #ifdef ADB_PSW_BIT
  71     psw_hi();
  72 #endif
  73 }
  74
  75 #ifdef ADB_PSW_BIT
  76 bool adb_host_psw(void)
  77 {
  78     return psw_in();
  79 }
  80 #endif
  81
  82 /*
  83  * Don't call this in a row without the delay, otherwise it makes some of poor controllers
  84  * overloaded and misses strokes. Recommended interval is 12ms.
  85  *
  86  * Thanks a lot, blargg!
  87  * <http://geekhack.org/index.php?topic=14290.msg1068919#msg1068919>
  88  * <http://geekhack.org/index.php?topic=14290.msg1070139#msg1070139>
  89  */
  90
  91 // ADB Bit Cells
  92 //
  93 // bit cell time: 70-130us
  94 // low part of bit0: 60-70% of bit cell
  95 // low part of bit1: 30-40% of bit cell
  96 //
  97 //    bit cell time         70us        130us
  98 //    --------------------------------------------
  99 //    low  part of bit0     42-49       78-91
 100 //    high part of bit0     21-28       39-52
 101 //    low  part of bit1     21-28       39-52
 102 //    high part of bit1     42-49       78-91
 103 //
 104 //
 105 // bit0:
 106 //    70us bit cell:
 107 //      ____________~~~~~~
 108 //      42-49        21-28
 109 //
 110 //    130us bit cell:
 111 //      ____________~~~~~~
 112 //      78-91        39-52
 113 //
 114 // bit1:
 115 //    70us bit cell:
 116 //      ______~~~~~~~~~~~~
 117 //      21-28        42-49
 118 //
 119 //    130us bit cell:
 120 //      ______~~~~~~~~~~~~
 121 //      39-52        78-91
 122 //
 123 // [from Apple IIgs Hardware Reference Second Edition]
 124
 125 enum {
 126     ADDR_KEYB  = 0x20,
 127     ADDR_MOUSE = 0x30
 128 };
 129
 130 uint16_t adb_host_kbd_recv(void)
 131 {
 132     return adb_host_dev_recv(ADDR_KEYB);
 133 }
 134
 135 #ifdef ADB_MOUSE_ENABLE
 136 void adb_mouse_init(void) {
 137             return;
 138 }
 139
 140 uint16_t adb_host_mouse_recv(void)
 141 {
 142     return adb_host_dev_recv(ADDR_MOUSE);
 143 }
 144 #endif
 145
 146 static inline uint16_t adb_host_dev_recv(uint8_t device)
 147 {
 148     uint16_t data = 0;
 149     cli();
 150     attention();
 151     send_byte(device|0x0C);     // Addr:Keyboard(0010)/Mouse(0011), Cmd:Talk(11), Register0(00)
 152     place_bit0();               // Stopbit(0)
 153     if (!wait_data_hi(500)) {    // Service Request(310us Adjustable Keyboard): just ignored
 154         sei();
 155         return -30;             // something wrong
 156     }
 157     if (!wait_data_lo(500)) {   // Tlt/Stop to Start(140-260us)
 158         sei();
 159         return 0;               // No data to send
 160     }
 161
 162     uint8_t n = 17; // start bit + 16 data bits
 163     do {
 164         uint8_t lo = (uint8_t) wait_data_hi(130);
 165         if (!lo)
 166             goto error;
 167
 168         uint8_t hi = (uint8_t) wait_data_lo(lo);
 169         if (!hi)
 170             goto error;
 171
 172         hi = lo - hi;
 173         lo = 130 - lo;
 174
 175         data <<= 1;
 176         if (lo < hi) {
 177             data |= 1;
 178         }
 179         else if (n == 17) {
 180             sei();
 181             return -20;
 182         }
 183     }
 184     while ( --n );
 185
 186     // Stop bit can't be checked normally since it could have service request lenghtening
 187     // and its high state never goes low.
 188     if (!wait_data_hi(351) || wait_data_lo(91)) {
 189         sei();
 190         return -21;
 191     }
 192     sei();
 193     return data;
 194
 195 error:
 196     sei();
 197     return -n;
 198 }
 199
 200 void adb_host_listen(uint8_t cmd, uint8_t data_h, uint8_t data_l)
 201 {
 202     cli();
 203     attention();
 204     send_byte(cmd);
 205     place_bit0();               // Stopbit(0)
 206     _delay_us(200);             // Tlt/Stop to Start
 207     place_bit1();               // Startbit(1)
 208     send_byte(data_h);
 209     send_byte(data_l);
 210     place_bit0();               // Stopbit(0);
 211     sei();
 212 }
 213
 214 // send state of LEDs
 215 void adb_host_kbd_led(uint8_t led)
 216 {
 217     // Addr:Keyboard(0010), Cmd:Listen(10), Register2(10)
 218     // send upper byte (not used)
 219     // send lower byte (bit2: ScrollLock, bit1: CapsLock, bit0:
 220     adb_host_listen(0x2A,0,led&0x07);
 221 }
 222
 223
 224 #ifdef ADB_PSW_BIT
 225 static inline void psw_lo()
 226 {
 227     ADB_DDR  |=  (1<<ADB_PSW_BIT);
 228     ADB_PORT &= ~(1<<ADB_PSW_BIT);
 229 }
 230 static inline void psw_hi()
 231 {
 232     ADB_PORT |=  (1<<ADB_PSW_BIT);
 233     ADB_DDR  &= ~(1<<ADB_PSW_BIT);
 234 }
 235 static inline bool psw_in()
 236 {
 237     ADB_PORT |=  (1<<ADB_PSW_BIT);
 238     ADB_DDR  &= ~(1<<ADB_PSW_BIT);
 239     return ADB_PIN&(1<<ADB_PSW_BIT);
 240 }
 241 #endif
 242
 243 static inline void attention(void)
 244 {
 245     data_lo();
 246     _delay_us(800-35); // bit1 holds lo for 35 more
 247     place_bit1();
 248 }
 249
 250 static inline void place_bit0(void)
 251 {
 252     data_lo();
 253     _delay_us(65);
 254     data_hi();
 255     _delay_us(35);
 256 }
 257
 258 static inline void place_bit1(void)
 259 {
 260     data_lo();
 261     _delay_us(35);
 262     data_hi();
 263     _delay_us(65);
 264 }
 265
 266 static inline void send_byte(uint8_t data)
 267 {
 268     for (int i = 0; i < 8; i++) {
 269         if (data&(0x80>>i))
 270             place_bit1();
 271         else
 272             place_bit0();
 273     }
 274 }
 275
 276 // These are carefully coded to take 6 cycles of overhead.
 277 // inline asm approach became too convoluted
 278 static inline uint16_t wait_data_lo(uint16_t us)
 279 {
 280     do {
 281         if ( !data_in() )
 282             break;
 283         _delay_us(1 - (6 * 1000000.0 / F_CPU));
 284     }
 285     while ( --us );
 286     return us;
 287 }
 288
 289 static inline uint16_t wait_data_hi(uint16_t us)
 290 {
 291     do {
 292         if ( data_in() )
 293             break;
 294         _delay_us(1 - (6 * 1000000.0 / F_CPU));
 295     }
 296     while ( --us );
 297     return us;
 298 }
 299
 300
 301 /*
 302 ADB Protocol
 303 ============
 304
 305 Resources
 306 ---------
 307 ADB - The Untold Story: Space Aliens Ate My Mouse
 308     http://developer.apple.com/legacy/mac/library/#technotes/hw/hw_01.html
 309 ADB Manager
 310     http://developer.apple.com/legacy/mac/library/documentation/mac/pdf/Devices/ADB_Manager.pdf
 311     Service request(5-17)
 312 Apple IIgs Hardware Reference Second Edition [Chapter6 p121]
 313     ftp://ftp.apple.asimov.net/pub/apple_II/documentation/Apple%20IIgs%20Hardware%20Reference.pdf
 314 ADB Keycode
 315     http://72.0.193.250/Documentation/macppc/adbkeycodes/
 316     http://m0115.web.fc2.com/m0115.jpg
 317     [Inside Macintosh volume V, pages 191-192]
 318     http://www.opensource.apple.com/source/IOHIDFamily/IOHIDFamily-421.18.3/IOHIDFamily/Cosmo_USB2ADB.c
 319 ADB Signaling
 320     http://kbdbabel.sourceforge.net/doc/kbd_signaling_pcxt_ps2_adb.pdf
 321 ADB Overview & History
 322     http://en.wikipedia.org/wiki/Apple_Desktop_Bus
 323 Microchip Application Note: ADB device(with code for PIC16C)
 324     http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1824&appnote=en011062
 325 AVR ATtiny2131 ADB to PS/2 converter(Japanese)
 326     http://hp.vector.co.jp/authors/VA000177/html/KeyBoardA5DEA5CBA5A2II.html
 327
 328
 329 Pinouts
 330 -------
 331     ADB female socket from the front:
 332     __________
 333     |        | <--- top
 334     | 4o  o3 |
 335     |2o    o1|
 336     |   ==   |
 337     |________| <--- bottom
 338       |    |   <--- 4pins
 339
 340
 341     ADB female socket from bottom:
 342
 343     ========== <--- front
 344     |        |
 345     |        |
 346     |2o    o1|
 347     |4o    o3|
 348     ---------- <--- back
 349
 350     1: Data
 351     2: Power SW(low when press Power key)
 352     3: Vcc(5V)
 353     4: GND
 354
 355
 356 Commands
 357 --------
 358     ADB command is 1byte and consists of 4bit-address, 2bit-command
 359     type and 2bit-register. The commands are always sent by Host.
 360
 361     Command format:
 362     7 6 5 4 3 2 1 0
 363     | | | |------------ address
 364             | |-------- command type
 365                 | |---- register
 366
 367     bits                commands
 368     ------------------------------------------------------
 369     - - - - 0 0 0 0     Send Request(reset all devices)
 370     A A A A 0 0 0 1     Flush(reset a device)
 371     - - - - 0 0 1 0     Reserved
 372     - - - - 0 0 1 1     Reserved
 373     - - - - 0 1 - -     Reserved
 374     A A A A 1 0 R R     Listen(write to a device)
 375     A A A A 1 1 R R     Talk(read from a device)
 376
 377     The command to read keycodes from keyboard is 0x2C which
 378     consist of keyboard address 2 and Talk against register 0.
 379
 380     Address:
 381     2:  keyboard
 382     3:  mice
 383
 384     Registers:
 385     0: application(keyboard uses this to store its data.)
 386     1: application
 387     2: application(keyboard uses this for LEDs and state of modifiers)
 388     3: status and command
 389
 390
 391 Communication
 392 -------------
 393     This is a minimum information for keyboard communication.
 394     See "Resources" for detail.
 395
 396     Signaling:
 397
 398     ~~~~____________~~||||||||||||__~~~~~_~~|||||||||||||||__~~~~
 399
 400         |800us     |  |7 Command 0|  |   |  |15-64  Data  0|Stopbit(0)
 401         +Attention |              |  |   +Startbit(1)
 402                    +Startbit(1)   |  +Tlt(140-260us)
 403                                   +stopbit(0)
 404
 405     Bit cells:
 406
 407     bit0: ______~~~
 408           65    :35us
 409
 410     bit1: ___~~~~~~
 411           35 :65us
 412
 413     bit0 low time: 60-70% of bit cell(42-91us)
 414     bit1 low time: 30-40% of bit cell(21-52us)
 415     bit cell time: 70-130us
 416     [from Apple IIgs Hardware Reference Second Edition]
 417
 418     Criterion for bit0/1:
 419     After 55us if line is low/high then bit is 0/1.
 420
 421     Attention & start bit:
 422     Host asserts low in 560-1040us then places start bit(1).
 423
 424     Tlt(Stop to Start):
 425     Bus stays high in 140-260us then device places start bit(1).
 426
 427     Global reset:
 428     Host asserts low in 2.8-5.2ms. All devices are forced to reset.
 429
 430     Service request from device(Srq):
 431     Device can request to send at commad(Global only?) stop bit.
 432     Requesting device keeps low for 140-260us at stop bit of command.
 433
 434
 435 Keyboard Data(Register0)
 436     This 16bit data can contains two keycodes and two released flags.
 437     First keycode is palced in upper byte. When one keyocode is sent,
 438     lower byte is 0xFF.
 439     Release flag is 1 when key is released.
 440
 441     1514 . . . . . 8 7 6 . . . . . 0
 442      | | | | | | | | | +-+-+-+-+-+-+-   Keycode2
 443      | | | | | | | | +---------------   Released2(1 when the key is released)
 444      | +-+-+-+-+-+-+-----------------   Keycode1
 445      +-------------------------------   Released1(1 when the key is released)
 446
 447     Keycodes:
 448     Scancode consists of 7bit keycode and 1bit release flag.
 449     Device can send two keycodes at once. If just one keycode is sent
 450     keycode1 contains it and keyocode2 is 0xFF.
 451
 452     Power switch:
 453     You can read the state from PSW line(active low) however
 454     the switch has a special scancode 0x7F7F, so you can
 455     also read from Data line. It uses 0xFFFF for release scancode.
 456
 457 Keyboard LEDs & state of keys(Register2)
 458     This register hold current state of three LEDs and nine keys.
 459     The state of LEDs can be changed by sending Listen command.
 460
 461     1514 . . . . . . 7 6 5 . 3 2 1 0
 462      | | | | | | | | | | | | | | | +-   LED1(NumLock)
 463      | | | | | | | | | | | | | | +---   LED2(CapsLock)
 464      | | | | | | | | | | | | | +-----   LED3(ScrollLock)
 465      | | | | | | | | | | +-+-+-------   Reserved
 466      | | | | | | | | | +-------------   ScrollLock
 467      | | | | | | | | +---------------   NumLock
 468      | | | | | | | +-----------------   Apple/Command
 469      | | | | | | +-------------------   Option
 470      | | | | | +---------------------   Shift
 471      | | | | +-----------------------   Control
 472      | | | +-------------------------   Reset/Power
 473      | | +---------------------------   CapsLock
 474      | +-----------------------------   Delete
 475      +-------------------------------   Reserved
 476
 477 END_OF_ADB
 478 */