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