core: Add comment of register 3 of ADB
[tmk_keyboard.git] / tmk_core / protocol / adb.c
CommitLineData
a074364c 1/*
2Copyright 2011 Jun WAKO <wakojun@gmail.com>
3Copyright 2013 Shay Green <gblargg@gmail.com>
4
5This software is licensed with a Modified BSD License.
6All of this is supposed to be Free Software, Open Source, DFSG-free,
7GPL-compatible, and OK to use in both free and proprietary applications.
8Additions and corrections to this file are welcome.
9
10
11Redistribution and use in source and binary forms, with or without
12modification, 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
26THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
27AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
30LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36POSSIBILITY 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
52static inline void psw_lo(void);
53static inline void psw_hi(void);
54static inline bool psw_in(void);
55#endif
56
57static inline void attention(void);
58static inline void place_bit0(void);
59static inline void place_bit1(void);
60static inline void send_byte(uint8_t data);
61static inline uint16_t wait_data_lo(uint16_t us);
62static inline uint16_t wait_data_hi(uint16_t us);
63
64
65void adb_host_init(void)
66{
67 ADB_PORT &= ~(1<<ADB_DATA_BIT);
68 data_hi();
69#ifdef ADB_PSW_BIT
70 psw_hi();
71#endif
72}
73
74#ifdef ADB_PSW_BIT
75bool adb_host_psw(void)
76{
77 return psw_in();
78}
79#endif
80
81/*
82 * Don't call this in a row without the delay, otherwise it makes some of poor controllers
83 * overloaded and misses strokes. Recommended interval is 12ms.
84 *
85 * Thanks a lot, blargg!
86 * <http://geekhack.org/index.php?topic=14290.msg1068919#msg1068919>
87 * <http://geekhack.org/index.php?topic=14290.msg1070139#msg1070139>
88 */
a074364c 89uint16_t adb_host_kbd_recv(void)
4d116a04 90{
d702fe75 91 return adb_host_talk(ADB_ADDR_KEYBOARD, ADB_REG_0);
4d116a04 92}
93
94#ifdef ADB_MOUSE_ENABLE
95void adb_mouse_init(void) {
96 return;
97}
98
99uint16_t adb_host_mouse_recv(void)
100{
d702fe75 101 return adb_host_talk(ADB_ADDR_MOUSE, ADB_REG_0);
4d116a04 102}
103#endif
104
d702fe75 105uint16_t adb_host_talk(uint8_t addr, uint8_t reg)
a074364c 106{
107 uint16_t data = 0;
108 cli();
109 attention();
d702fe75 110 send_byte((addr<<4) | (ADB_CMD_TALK<<2) | reg);
a074364c 111 place_bit0(); // Stopbit(0)
112 if (!wait_data_hi(500)) { // Service Request(310us Adjustable Keyboard): just ignored
113 sei();
114 return -30; // something wrong
115 }
116 if (!wait_data_lo(500)) { // Tlt/Stop to Start(140-260us)
117 sei();
118 return 0; // No data to send
119 }
d702fe75 120
a074364c 121 uint8_t n = 17; // start bit + 16 data bits
122 do {
123 uint8_t lo = (uint8_t) wait_data_hi(130);
124 if (!lo)
125 goto error;
d702fe75 126
a074364c 127 uint8_t hi = (uint8_t) wait_data_lo(lo);
128 if (!hi)
129 goto error;
d702fe75 130
a074364c 131 hi = lo - hi;
132 lo = 130 - lo;
d702fe75 133
a074364c 134 data <<= 1;
135 if (lo < hi) {
136 data |= 1;
137 }
138 else if (n == 17) {
139 sei();
140 return -20;
141 }
142 }
143 while ( --n );
144
145 // Stop bit can't be checked normally since it could have service request lenghtening
146 // and its high state never goes low.
147 if (!wait_data_hi(351) || wait_data_lo(91)) {
148 sei();
149 return -21;
150 }
151 sei();
152 return data;
153
154error:
155 sei();
156 return -n;
157}
158
159void adb_host_listen(uint8_t cmd, uint8_t data_h, uint8_t data_l)
160{
161 cli();
162 attention();
163 send_byte(cmd);
164 place_bit0(); // Stopbit(0)
165 _delay_us(200); // Tlt/Stop to Start
166 place_bit1(); // Startbit(1)
d702fe75 167 send_byte(data_h);
a074364c 168 send_byte(data_l);
169 place_bit0(); // Stopbit(0);
170 sei();
171}
172
173// send state of LEDs
174void adb_host_kbd_led(uint8_t led)
175{
176 // Addr:Keyboard(0010), Cmd:Listen(10), Register2(10)
177 // send upper byte (not used)
178 // send lower byte (bit2: ScrollLock, bit1: CapsLock, bit0:
179 adb_host_listen(0x2A,0,led&0x07);
180}
181
182
183#ifdef ADB_PSW_BIT
184static inline void psw_lo()
185{
186 ADB_DDR |= (1<<ADB_PSW_BIT);
187 ADB_PORT &= ~(1<<ADB_PSW_BIT);
188}
189static inline void psw_hi()
190{
191 ADB_PORT |= (1<<ADB_PSW_BIT);
192 ADB_DDR &= ~(1<<ADB_PSW_BIT);
193}
194static inline bool psw_in()
195{
196 ADB_PORT |= (1<<ADB_PSW_BIT);
197 ADB_DDR &= ~(1<<ADB_PSW_BIT);
198 return ADB_PIN&(1<<ADB_PSW_BIT);
199}
200#endif
201
202static inline void attention(void)
203{
204 data_lo();
205 _delay_us(800-35); // bit1 holds lo for 35 more
206 place_bit1();
207}
208
209static inline void place_bit0(void)
210{
211 data_lo();
212 _delay_us(65);
213 data_hi();
214 _delay_us(35);
215}
216
217static inline void place_bit1(void)
218{
219 data_lo();
220 _delay_us(35);
221 data_hi();
222 _delay_us(65);
223}
224
225static inline void send_byte(uint8_t data)
226{
227 for (int i = 0; i < 8; i++) {
228 if (data&(0x80>>i))
229 place_bit1();
230 else
231 place_bit0();
232 }
233}
234
235// These are carefully coded to take 6 cycles of overhead.
236// inline asm approach became too convoluted
237static inline uint16_t wait_data_lo(uint16_t us)
238{
239 do {
240 if ( !data_in() )
241 break;
242 _delay_us(1 - (6 * 1000000.0 / F_CPU));
243 }
244 while ( --us );
245 return us;
246}
247
248static inline uint16_t wait_data_hi(uint16_t us)
249{
250 do {
251 if ( data_in() )
252 break;
253 _delay_us(1 - (6 * 1000000.0 / F_CPU));
254 }
255 while ( --us );
256 return us;
257}
258
259
260/*
261ADB Protocol
262============
263
264Resources
265---------
266ADB - The Untold Story: Space Aliens Ate My Mouse
267 http://developer.apple.com/legacy/mac/library/#technotes/hw/hw_01.html
268ADB Manager
269 http://developer.apple.com/legacy/mac/library/documentation/mac/pdf/Devices/ADB_Manager.pdf
270 Service request(5-17)
271Apple IIgs Hardware Reference Second Edition [Chapter6 p121]
272 ftp://ftp.apple.asimov.net/pub/apple_II/documentation/Apple%20IIgs%20Hardware%20Reference.pdf
273ADB Keycode
274 http://72.0.193.250/Documentation/macppc/adbkeycodes/
275 http://m0115.web.fc2.com/m0115.jpg
276 [Inside Macintosh volume V, pages 191-192]
277 http://www.opensource.apple.com/source/IOHIDFamily/IOHIDFamily-421.18.3/IOHIDFamily/Cosmo_USB2ADB.c
278ADB Signaling
279 http://kbdbabel.sourceforge.net/doc/kbd_signaling_pcxt_ps2_adb.pdf
280ADB Overview & History
281 http://en.wikipedia.org/wiki/Apple_Desktop_Bus
282Microchip Application Note: ADB device(with code for PIC16C)
283 http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1824&appnote=en011062
284AVR ATtiny2131 ADB to PS/2 converter(Japanese)
285 http://hp.vector.co.jp/authors/VA000177/html/KeyBoardA5DEA5CBA5A2II.html
286
287
288Pinouts
289-------
290 ADB female socket from the front:
291 __________
292 | | <--- top
293 | 4o o3 |
294 |2o o1|
295 | == |
296 |________| <--- bottom
297 | | <--- 4pins
298
299
300 ADB female socket from bottom:
301
302 ========== <--- front
303 | |
304 | |
305 |2o o1|
306 |4o o3|
307 ---------- <--- back
308
309 1: Data
310 2: Power SW(low when press Power key)
311 3: Vcc(5V)
312 4: GND
313
314
315Commands
316--------
317 ADB command is 1byte and consists of 4bit-address, 2bit-command
318 type and 2bit-register. The commands are always sent by Host.
319
320 Command format:
321 7 6 5 4 3 2 1 0
322 | | | |------------ address
323 | |-------- command type
324 | |---- register
325
326 bits commands
327 ------------------------------------------------------
328 - - - - 0 0 0 0 Send Request(reset all devices)
329 A A A A 0 0 0 1 Flush(reset a device)
330 - - - - 0 0 1 0 Reserved
331 - - - - 0 0 1 1 Reserved
332 - - - - 0 1 - - Reserved
333 A A A A 1 0 R R Listen(write to a device)
334 A A A A 1 1 R R Talk(read from a device)
335
336 The command to read keycodes from keyboard is 0x2C which
d702fe75 337 consist of keyboard address 2 and Talk against register 0.
a074364c 338
339 Address:
340 2: keyboard
341 3: mice
342
343 Registers:
344 0: application(keyboard uses this to store its data.)
345 1: application
346 2: application(keyboard uses this for LEDs and state of modifiers)
347 3: status and command
348
349
350Communication
351-------------
352 This is a minimum information for keyboard communication.
353 See "Resources" for detail.
354
355 Signaling:
356
357 ~~~~____________~~||||||||||||__~~~~~_~~|||||||||||||||__~~~~
358
359 |800us | |7 Command 0| | | |15-64 Data 0|Stopbit(0)
360 +Attention | | | +Startbit(1)
361 +Startbit(1) | +Tlt(140-260us)
362 +stopbit(0)
363
364 Bit cells:
365
366 bit0: ______~~~
367 65 :35us
368
369 bit1: ___~~~~~~
370 35 :65us
371
372 bit0 low time: 60-70% of bit cell(42-91us)
373 bit1 low time: 30-40% of bit cell(21-52us)
374 bit cell time: 70-130us
375 [from Apple IIgs Hardware Reference Second Edition]
376
377 Criterion for bit0/1:
378 After 55us if line is low/high then bit is 0/1.
379
380 Attention & start bit:
381 Host asserts low in 560-1040us then places start bit(1).
382
383 Tlt(Stop to Start):
384 Bus stays high in 140-260us then device places start bit(1).
385
386 Global reset:
387 Host asserts low in 2.8-5.2ms. All devices are forced to reset.
388
389 Service request from device(Srq):
390 Device can request to send at commad(Global only?) stop bit.
391 Requesting device keeps low for 140-260us at stop bit of command.
392
393
394Keyboard Data(Register0)
395 This 16bit data can contains two keycodes and two released flags.
396 First keycode is palced in upper byte. When one keyocode is sent,
397 lower byte is 0xFF.
398 Release flag is 1 when key is released.
399
400 1514 . . . . . 8 7 6 . . . . . 0
401 | | | | | | | | | +-+-+-+-+-+-+- Keycode2
402 | | | | | | | | +--------------- Released2(1 when the key is released)
403 | +-+-+-+-+-+-+----------------- Keycode1
404 +------------------------------- Released1(1 when the key is released)
405
406 Keycodes:
407 Scancode consists of 7bit keycode and 1bit release flag.
408 Device can send two keycodes at once. If just one keycode is sent
409 keycode1 contains it and keyocode2 is 0xFF.
410
411 Power switch:
412 You can read the state from PSW line(active low) however
413 the switch has a special scancode 0x7F7F, so you can
414 also read from Data line. It uses 0xFFFF for release scancode.
415
416Keyboard LEDs & state of keys(Register2)
417 This register hold current state of three LEDs and nine keys.
418 The state of LEDs can be changed by sending Listen command.
d702fe75 419
a074364c 420 1514 . . . . . . 7 6 5 . 3 2 1 0
421 | | | | | | | | | | | | | | | +- LED1(NumLock)
422 | | | | | | | | | | | | | | +--- LED2(CapsLock)
423 | | | | | | | | | | | | | +----- LED3(ScrollLock)
424 | | | | | | | | | | +-+-+------- Reserved
425 | | | | | | | | | +------------- ScrollLock
426 | | | | | | | | +--------------- NumLock
427 | | | | | | | +----------------- Apple/Command
428 | | | | | | +------------------- Option
429 | | | | | +--------------------- Shift
430 | | | | +----------------------- Control
431 | | | +------------------------- Reset/Power
432 | | +--------------------------- CapsLock
433 | +----------------------------- Delete
434 +------------------------------- Reserved
435
e6612962 436Address, Handler ID and bits(Register3)
437 1514131211 . . 8 7 . . . . . . 0
438 | | | | | | | | | | | | | | | |
439 | | | | | | | | +-+-+-+-+-+-+-+- Handler ID
440 | | | | +-+-+-+----------------- Address
441 | | | +------------------------- 0
442 | | +--------------------------- Service request enable(1 = enabled)
443 | +----------------------------- Exeptional event(alwyas 1 if not used)
444 +------------------------------- 0
445
d702fe75 446ADB Bit Cells
447 bit cell time: 70-130us
448 low part of bit0: 60-70% of bit cell
449 low part of bit1: 30-40% of bit cell
450
451 bit cell time 70us 130us
452 --------------------------------------------
453 low part of bit0 42-49 78-91
454 high part of bit0 21-28 39-52
455 low part of bit1 21-28 39-52
456 high part of bit1 42-49 78-91
457
458
459 bit0:
460 70us bit cell:
461 ____________~~~~~~
462 42-49 21-28
463
464 130us bit cell:
465 ____________~~~~~~
466 78-91 39-52
467
468 bit1:
469 70us bit cell:
470 ______~~~~~~~~~~~~
471 21-28 42-49
472
473 130us bit cell:
474 ______~~~~~~~~~~~~
475 39-52 78-91
476
477 [from Apple IIgs Hardware Reference Second Edition]
478
479Keyboard Handle ID
480 Apple Standard Keyboard M0116: 0x01
481 Apple Extended Keyboard M0115: 0x02
482 Apple Extended Keyboard II M3501: 0x02
483 Apple Adjustable Keybaord: 0x10
484
485 http://lxr.free-electrons.com/source/drivers/macintosh/adbhid.c?v=4.4#L802
486
a074364c 487END_OF_ADB
488*/
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