2 Copyright 2011 Jun WAKO <wakojun@gmail.com>
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.
10 Redistribution and use in source and binary forms, with or without
11 modification, are permitted provided that the following conditions are met:
13 * Redistributions of source code must retain the above copyright
14 notice, this list of conditions and the following disclaimer.
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
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.
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.
39 #include <util/delay.h>
41 #include <avr/interrupt.h>
45 static inline void data_lo(void);
46 static inline void data_hi(void);
47 static inline bool data_in(void);
49 static inline void psw_lo(void);
50 static inline void psw_hi(void);
51 static inline bool psw_in(void);
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(uint8_t us);
61 static inline uint8_t wait_data_hi(uint8_t us);
64 void adb_host_init(void)
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);
79 bool adb_host_psw(void)
85 uint16_t adb_host_kbd_recv(void)
89 send_byte(0x2C); // Addr:Keyboard(0010), Cmd:Talk(11), Register0(00)
90 place_bit0(); // Stopbit(0)
91 if (!wait_data_lo(0xFF)) // Tlt/Stop to Start(140-260us)
92 return 0; // No data to send
93 if (!read_bit()) // Startbit(1)
96 // ad hoc fix: without block inerrupt read wrong bit occasionally and get keys stuck
99 data = (data<<8) | read_byte();
102 if (read_bit()) // Stopbit(0)
107 void adb_host_listen(uint8_t cmd, uint8_t data_h, uint8_t data_l)
111 place_bit0(); // Stopbit(0)
112 _delay_us(200); // Tlt/Stop to Start
113 place_bit1(); // Startbit(1)
116 place_bit0(); // Stopbit(0);
119 // send state of LEDs
120 void adb_host_kbd_led(uint8_t led)
122 // Addr:Keyboard(0010), Cmd:Listen(10), Register2(10)
123 // send upper byte (not used)
124 // send lower byte (bit2: ScrollLock, bit1: CapsLock, bit0:
125 adb_host_listen(0x2A,0,led&0x07);
129 static inline void data_lo()
131 ADB_DDR |= (1<<ADB_DATA_BIT);
132 ADB_PORT &= ~(1<<ADB_DATA_BIT);
134 static inline void data_hi()
136 ADB_PORT |= (1<<ADB_DATA_BIT);
137 ADB_DDR &= ~(1<<ADB_DATA_BIT);
139 static inline bool data_in()
141 ADB_PORT |= (1<<ADB_DATA_BIT);
142 ADB_DDR &= ~(1<<ADB_DATA_BIT);
143 return ADB_PIN&(1<<ADB_DATA_BIT);
147 static inline void psw_lo()
149 ADB_DDR |= (1<<ADB_PSW_BIT);
150 ADB_PORT &= ~(1<<ADB_PSW_BIT);
152 static inline void psw_hi()
154 ADB_PORT |= (1<<ADB_PSW_BIT);
155 ADB_DDR &= ~(1<<ADB_PSW_BIT);
157 static inline bool psw_in()
159 ADB_PORT |= (1<<ADB_PSW_BIT);
160 ADB_DDR &= ~(1<<ADB_PSW_BIT);
161 return ADB_PIN&(1<<ADB_PSW_BIT);
165 static inline void attention(void)
172 static inline void place_bit0(void)
180 static inline void place_bit1(void)
188 static inline void send_byte(uint8_t data)
190 for (int i = 0; i < 8; i++) {
198 static inline bool read_bit(void)
208 // bit0 low time: 60-70% of bit cell(42-91us)
209 // bit1 low time: 30-40% of bit cell(21-52us)
210 // bit cell time: 70-130us
211 // [from Apple IIgs Hardware Reference Second Edition]
213 // After 55us if data line is low/high then bit is 0/1.
214 // Too simple to rely on?
216 wait_data_lo(75); // wait the beginning of bit cell
219 wait_data_hi(36); // wait high part of bit cell
223 static inline uint8_t read_byte(void)
226 for (int i = 0; i < 8; i++) {
234 static inline uint8_t wait_data_lo(uint8_t us)
236 while (data_in() && us) {
243 static inline uint8_t wait_data_hi(uint8_t us)
245 while (!data_in() && us) {
259 ADB - The Untold Story: Space Aliens Ate My Mouse
260 http://developer.apple.com/legacy/mac/library/#technotes/hw/hw_01.html
261 Apple IIgs Hardware Reference Second Edition [p80(Chapter6 p121)]
262 ftp://ftp.apple.asimov.net/pub/apple_II/documentation/Apple%20IIgs%20Hardware%20Reference.pdf
264 http://72.0.193.250/Documentation/macppc/adbkeycodes/
265 http://m0115.web.fc2.com/m0115.jpg
266 [Inside Macintosh volume V, pages 191-192]
268 http://kbdbabel.sourceforge.net/doc/kbd_signaling_pcxt_ps2_adb.pdf
269 ADB Overview & History
270 http://en.wikipedia.org/wiki/Apple_Desktop_Bus
271 Microchip Application Note: ADB device(with code for PIC16C)
272 http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1824&appnote=en011062
273 AVR ATtiny2131 ADB to PS/2 converter(Japanese)
274 http://hp.vector.co.jp/authors/VA000177/html/KeyBoardA5DEA5CBA5A2II.html
279 ADB female socket from the front:
285 |________| <--- bottom
289 ADB female socket from bottom:
291 ========== <--- front
299 2: Power SW(low when press Power key)
306 ADB command is 1byte and consists of 4bit-address, 2bit-command
307 type and 2bit-register. The commands are always sent by Host.
311 | | | |------------ address
312 | |-------- command type
316 ------------------------------------------------------
317 - - - - 0 0 0 0 Send Request(reset all devices)
318 A A A A 0 0 0 1 Flush(reset a device)
319 - - - - 0 0 1 0 Reserved
320 - - - - 0 0 1 1 Reserved
321 - - - - 0 1 - - Reserved
322 A A A A 1 0 R R Listen(write to a device)
323 A A A A 1 1 R R Talk(read from a device)
325 The command to read keycodes from keyboard is 0x2C which
326 consist of keyboard address 2 and Talk against register 0.
333 0: application(keyobard uses this to store its data.)
335 2: application(keyboard uses this for LEDs and state of modifiers)
336 3: status and command
341 This is a minimum information for keyboard communication.
342 See "Resources" for detail.
346 ~~~~____________~~||||||||||||__~~~~~_~~|||||||||||||||__~~~~
348 |800us | |7 Command 0| | | |15-64 Data 0|Stopbit(0)
349 +Attention | | | +Startbit(1)
350 +Startbit(1) | +Tlt(140-260us)
361 bit0 low time: 60-70% of bit cell(42-91us)
362 bit1 low time: 30-40% of bit cell(21-52us)
363 bit cell time: 70-130us
364 [from Apple IIgs Hardware Reference Second Edition]
366 Criterion for bit0/1:
367 After 55us if line is low/high then bit is 0/1.
369 Attention & start bit:
370 Host asserts low in 560-1040us then places start bit(1).
373 Bus stays high in 140-260us then device places start bit(1).
376 Host asserts low in 2.8-5.2ms. All devices are forced to reset.
378 Send request from device(Srq):
379 Device can request to send at commad(Global only?) stop bit.
380 keep low for 300us to request.
383 Keyboard Data(Register0)
384 This 16bit data can contains two keycodes and two released flags.
385 First keycode is palced in upper byte. When one keyocode is sent,
387 Release flag is 1 when key is released.
389 1514 . . . . . 8 7 6 . . . . . 0
390 | | | | | | | | | +-+-+-+-+-+-+- Keycode2
391 | | | | | | | | +--------------- Released2(1 when the key is released)
392 | +-+-+-+-+-+-+----------------- Keycode1
393 +------------------------------- Released1(1 when the key is released)
396 Scancode consists of 7bit keycode and 1bit release flag.
397 Device can send two keycodes at once. If just one keycode is sent
398 keycode1 contains it and keyocode2 is 0xFF.
401 You can read the state from PSW line(active low) however
402 the switch has a special scancode 0x7F7F, so you can
403 also read from Data line. It uses 0xFFFF for release scancode.
405 Keyboard LEDs & state of keys(Register2)
406 This register hold current state of three LEDs and nine keys.
407 The state of LEDs can be changed by sending Listen command.
409 1514 . . . . . . 7 6 5 . 3 2 1 0
410 | | | | | | | | | | | | | | | +- LED1(NumLock)
411 | | | | | | | | | | | | | | +--- LED2(CapsLock)
412 | | | | | | | | | | | | | +----- LED3(ScrollLock)
413 | | | | | | | | | | +-+-+------- Reserved
414 | | | | | | | | | +------------- ScrollLock
415 | | | | | | | | +--------------- NumLock
416 | | | | | | | +----------------- Apple/Command
417 | | | | | | +------------------- Option
418 | | | | | +--------------------- Shift
419 | | | | +----------------------- Control
420 | | | +------------------------- Reset/Power
421 | | +--------------------------- CapsLock
422 | +----------------------------- Delete
423 +------------------------------- Reserved