diff options
Diffstat (limited to 'adb.c')
| -rw-r--r-- | adb.c | 213 |
1 files changed, 213 insertions, 0 deletions
@@ -1,3 +1,39 @@ +/* +Copyright (c) 2011 Jun WAKO <wakojun@gmail.com> + +This software is licensed with a Modified BSD License. +All of this is supposed to be Free Software, Open Source, DFSG-free, +GPL-compatible, and OK to use in both free and proprietary applications. +Additions and corrections to this file are welcome. + + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + +* Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + +* Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in + the documentation and/or other materials provided with the + distribution. + +* Neither the name of the copyright holders nor the names of + contributors may be used to endorse or promote products derived + from this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE +LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) +ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +POSSIBILITY OF SUCH DAMAGE. +*/ #include <stdbool.h> #include <util/delay.h> #include <avr/io.h> @@ -191,3 +227,180 @@ static inline uint8_t wait_data_hi(uint8_t us) } return us; } + + +/* +ADB Protocol +============ + +Resources +--------- +ADB - The Untold Story: Space Aliens Ate My Mouse + http://developer.apple.com/legacy/mac/library/#technotes/hw/hw_01.html +Apple IIgs Hardware Reference Second Edition [p80(Chapter6 p121)] + ftp://ftp.apple.asimov.net/pub/apple_II/documentation/Apple%20IIgs%20Hardware%20Reference.pdf +ADB Keycode + http://72.0.193.250/Documentation/macppc/adbkeycodes/ + http://m0115.web.fc2.com/m0115.jpg + [Inside Macintosh volume V, pages 191-192] +ADB Signaling + http://kbdbabel.sourceforge.net/doc/kbd_signaling_pcxt_ps2_adb.pdf +ADB Overview & History + http://en.wikipedia.org/wiki/Apple_Desktop_Bus +Microchip Application Note: ADB device(with code for PIC16C) + http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1824&appnote=en011062 +AVR ATtiny2131 ADB to PS/2 converter(Japanese) + http://hp.vector.co.jp/authors/VA000177/html/KeyBoardA5DEA5CBA5A2II.html + + +Pinouts +------- + ADB female socket from the front: + __________ + | | <--- top + | 4o o3 | + |2o o1| + | == | + |________| <--- bottom + | | <--- 4pins + + + ADB female socket from bottom: + + ========== <--- front + | | + | | + |2o o1| + |4o o3| + ---------- <--- back + + 1: Data + 2: Power SW(low when press Power key) + 3: Vcc(5V) + 4: GND + + + +Commands +-------- + ADB command is 1byte and consists of 4bit-address, 2bit-command + type and 2bit-register. The commands are always sent by Host. + + Command format: + 7 6 5 4 3 2 1 0 + | | | |------------ address + | |-------- command type + | |---- register + + bits commands + ------------------------------------------------------ + - - - - 0 0 0 0 Send Request(reset all devices) + A A A A 0 0 0 1 Flush(reset a device) + - - - - 0 0 1 0 Reserved + - - - - 0 0 1 1 Reserved + - - - - 0 1 - - Reserved + A A A A 1 0 R R Listen(write to a device) + A A A A 1 1 R R Talk(read from a device) + + The command to read keycodes from keyboard is 0x2C which + consist of keyboard address 2 and Talk against register 0. + + Address: + 2: keyboard + 3: mice + + Registers: + 0: application(keyobard uses this to store its data.) + 1: application + 2: application(keyboard uses this for LEDs and state of modifiers) + 3: status and command + + +Communication +------------- + This is a minimum information for keyboard communication. + See "Resources" for detail. + + Signaling: + + ~~~~____________~~||||||||||||__~~~~~_~~|||||||||||||||__~~~~ + + |800us | |7 Command 0| | | |15-64 Data 0|Stopbit(0) + +Attention | | | +Startbit(1) + +Startbit(1) | +Tlt(140-260us) + +stopbit(0) + + Bit cells: + + bit0: ______~~~ + 65 :35us + + bit1: ___~~~~~~ + 35 :65us + + bit0 low time: 60-70% of bit cell(42-91us) + bit1 low time: 30-40% of bit cell(21-52us) + bit cell time: 70-130us + [from Apple IIgs Hardware Reference Second Edition] + + Criterion for bit0/1: + After 55us if line is low/high then bit is 0/1. + + Attention & start bit: + Host asserts low in 560-1040us then places start bit(1). + + Tlt(Stop to Start): + Bus stays high in 140-260us then device places start bit(1). + + Global reset: + Host asserts low in 2.8-5.2ms. All devices are forced to reset. + + Send request from device(Srq): + Device can request to send at commad(Global only?) stop bit. + keep low for 300us to request. + + +Keyboard Data(Register0) + This 16bit data can contains two keycodes and two released flags. + First keycode is palced in upper byte. When one keyocode is sent, + lower byte is 0xFF. + Release flag is 1 when key is released. + + 1514 . . . . . 8 7 6 . . . . . 0 + | | | | | | | | | +-+-+-+-+-+-+- Keycode2 + | | | | | | | | +--------------- Released2(1 when the key is released) + | +-+-+-+-+-+-+----------------- Keycode1 + +------------------------------- Released1(1 when the key is released) + + Keycodes: + Scancode consists of 7bit keycode and 1bit release flag. + Device can send two keycodes at once. If just one keycode is sent + keycode1 contains it and keyocode2 is 0xFF. + + Power switch: + You can read the state from PSW line(active low) however + the switch has a special scancode 0x7F7F, so you can + also read from Data line. It uses 0xFFFF for release scancode. + +Keyboard LEDs & state of keys(Register2) + This register hold current state of three LEDs and nine keys. + The state of LEDs can be changed by sending Listen command. + + 1514 . . . . . . 7 6 5 . 3 2 1 0 + | | | | | | | | | | | | | | | +- LED1(NumLock) + | | | | | | | | | | | | | | +--- LED2(CapsLock) + | | | | | | | | | | | | | +----- LED3(ScrollLock) + | | | | | | | | | | +-+-+------- Reserved + | | | | | | | | | +------------- ScrollLock + | | | | | | | | +--------------- NumLock + | | | | | | | +----------------- Apple/Command + | | | | | | +------------------- Option + | | | | | +--------------------- Shift + | | | | +----------------------- Control + | | | +------------------------- Reset/Power + | | +--------------------------- CapsLock + | +----------------------------- Delete + +------------------------------- Reserved + +END_OF_ADB +*/ |