/*
Copyright 2011 Jun WAKO <wakojun@gmail.com>
+Copyright 2013 Shay Green <gblargg@gmail.com>
This software is licensed with a Modified BSD License.
All of this is supposed to be Free Software, Open Source, DFSG-free,
#include "adb.h"
-static inline void data_lo(void);
-static inline void data_hi(void);
-static inline bool data_in(void);
+// GCC doesn't inline functions normally
+#define data_lo() (ADB_DDR |= (1<<ADB_DATA_BIT))
+#define data_hi() (ADB_DDR &= ~(1<<ADB_DATA_BIT))
+#define data_in() (ADB_PIN & (1<<ADB_DATA_BIT))
+
#ifdef ADB_PSW_BIT
static inline void psw_lo(void);
static inline void psw_hi(void);
static inline void place_bit0(void);
static inline void place_bit1(void);
static inline void send_byte(uint8_t data);
-static inline bool read_bit(void);
-static inline uint8_t read_byte(void);
-static inline uint8_t wait_data_lo(uint8_t us);
-static inline uint8_t wait_data_hi(uint8_t us);
+static inline uint16_t wait_data_lo(uint16_t us);
+static inline uint16_t wait_data_hi(uint16_t us);
void adb_host_init(void)
{
+ ADB_PORT &= ~(1<<ADB_DATA_BIT);
data_hi();
#ifdef ADB_PSW_BIT
psw_hi();
#endif
-
- // Enable keyboard left/right modifier distinction
- // Addr:Keyboard(0010), Cmd:Listen(10), Register3(11)
- // upper byte: reserved bits 0000, device address 0010
- // lower byte: device handler 00000011
- adb_host_listen(0x2B,0x02,0x03);
}
#ifdef ADB_PSW_BIT
}
#endif
+/*
+ * Don't call this in a row without the delay, otherwise it makes some of poor controllers
+ * overloaded and misses strokes. Recommended interval is 12ms.
+ *
+ * Thanks a lot, blargg!
+ * <http://geekhack.org/index.php?topic=14290.msg1068919#msg1068919>
+ * <http://geekhack.org/index.php?topic=14290.msg1070139#msg1070139>
+ */
+
+// ADB Bit Cells
+//
+// bit cell time: 70-130us
+// low part of bit0: 60-70% of bit cell
+// low part of bit1: 30-40% of bit cell
+//
+// bit cell time 70us 130us
+// --------------------------------------------
+// low part of bit0 42-49 78-91
+// high part of bit0 21-28 39-52
+// low part of bit1 21-28 39-52
+// high part of bit1 42-49 78-91
+//
+//
+// bit0:
+// 70us bit cell:
+// ____________~~~~~~
+// 42-49 21-28
+//
+// 130us bit cell:
+// ____________~~~~~~
+// 78-91 39-52
+//
+// bit1:
+// 70us bit cell:
+// ______~~~~~~~~~~~~
+// 21-28 42-49
+//
+// 130us bit cell:
+// ______~~~~~~~~~~~~
+// 39-52 78-91
+//
+// [from Apple IIgs Hardware Reference Second Edition]
+
uint16_t adb_host_kbd_recv(void)
{
uint16_t data = 0;
+ cli();
attention();
send_byte(0x2C); // Addr:Keyboard(0010), Cmd:Talk(11), Register0(00)
place_bit0(); // Stopbit(0)
- if (!wait_data_lo(0xFF)) // Tlt/Stop to Start(140-260us)
+ if (!wait_data_hi(500)) { // Service Request(310us Adjustable Keyboard): just ignored
+ sei();
+ return -30; // something wrong
+ }
+ if (!wait_data_lo(500)) { // Tlt/Stop to Start(140-260us)
+ sei();
return 0; // No data to send
- if (!read_bit()) // Startbit(1)
- return -2;
+ }
+
+ uint8_t n = 17; // start bit + 16 data bits
+ do {
+ uint8_t lo = (uint8_t) wait_data_hi(130);
+ if (!lo)
+ goto error;
+
+ uint8_t hi = (uint8_t) wait_data_lo(lo);
+ if (!hi)
+ goto error;
+
+ hi = lo - hi;
+ lo = 130 - lo;
+
+ data <<= 1;
+ if (lo < hi) {
+ data |= 1;
+ }
+ else if (n == 17) {
+ sei();
+ return -20;
+ }
+ }
+ while ( --n );
- // ad hoc fix: without block inerrupt read wrong bit occasionally and get keys stuck
- cli();
- data = read_byte();
- data = (data<<8) | read_byte();
+ // Stop bit can't be checked normally since it could have service request lenghtening
+ // and its high state never goes low.
+ if (!wait_data_hi(351) || wait_data_lo(91)) {
+ sei();
+ return -21;
+ }
sei();
-
- if (read_bit()) // Stopbit(0)
- return -3;
return data;
+
+error:
+ sei();
+ return -n;
}
void adb_host_listen(uint8_t cmd, uint8_t data_h, uint8_t data_l)
{
+ cli();
attention();
send_byte(cmd);
place_bit0(); // Stopbit(0)
send_byte(data_h);
send_byte(data_l);
place_bit0(); // Stopbit(0);
+ sei();
}
// send state of LEDs
}
-static inline void data_lo()
-{
- ADB_DDR |= (1<<ADB_DATA_BIT);
- ADB_PORT &= ~(1<<ADB_DATA_BIT);
-}
-static inline void data_hi()
-{
- ADB_PORT |= (1<<ADB_DATA_BIT);
- ADB_DDR &= ~(1<<ADB_DATA_BIT);
-}
-static inline bool data_in()
-{
- ADB_PORT |= (1<<ADB_DATA_BIT);
- ADB_DDR &= ~(1<<ADB_DATA_BIT);
- return ADB_PIN&(1<<ADB_DATA_BIT);
-}
-
#ifdef ADB_PSW_BIT
static inline void psw_lo()
{
static inline void attention(void)
{
data_lo();
- _delay_us(700);
+ _delay_us(800-35); // bit1 holds lo for 35 more
place_bit1();
}
}
}
-static inline bool read_bit(void)
-{
- // ADB 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]
- //
- // After 55us if data line is low/high then bit is 0/1.
- // Too simple to rely on?
- bool bit;
- wait_data_lo(75); // wait the beginning of bit cell
- _delay_us(55);
- bit = data_in();
- wait_data_hi(36); // wait high part of bit cell
- return bit;
-}
-
-static inline uint8_t read_byte(void)
-{
- uint8_t data = 0;
- for (int i = 0; i < 8; i++) {
- data <<= 1;
- if (read_bit())
- data = data | 1;
- }
- return data;
-}
-
-static inline uint8_t wait_data_lo(uint8_t us)
+// These are carefully coded to take 6 cycles of overhead.
+// inline asm approach became too convoluted
+static inline uint16_t wait_data_lo(uint16_t us)
{
- while (data_in() && us) {
- _delay_us(1);
- us--;
+ do {
+ if ( !data_in() )
+ break;
+ _delay_us(1 - (6 * 1000000.0 / F_CPU));
}
+ while ( --us );
return us;
}
-static inline uint8_t wait_data_hi(uint8_t us)
+static inline uint16_t wait_data_hi(uint16_t us)
{
- while (!data_in() && us) {
- _delay_us(1);
- us--;
+ do {
+ if ( data_in() )
+ break;
+ _delay_us(1 - (6 * 1000000.0 / F_CPU));
}
+ while ( --us );
return us;
}
---------
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)]
+ADB Manager
+ http://developer.apple.com/legacy/mac/library/documentation/mac/pdf/Devices/ADB_Manager.pdf
+ Service request(5-17)
+Apple IIgs Hardware Reference Second Edition [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/
Global reset:
Host asserts low in 2.8-5.2ms. All devices are forced to reset.
- Send request from device(Srq):
+ Service request from device(Srq):
Device can request to send at commad(Global only?) stop bit.
- keep low for 300us to request.
+ Requesting device keeps low for 140-260us at stop bit of command.
Keyboard Data(Register0)
projects / tmk_firmware.git / blobdiff