Merge blargg's fix into adb.c

- <http://geekhack.org/index.php?topic=14290.msg1075201#msg1075201>

converter/adb_usb/led.c

@@ -15,12 +15,15 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include "stdint.h"
+#include <stdint.h>
+#include <util/delay.h>
 #include "adb.h"
 #include "led.h"
 
 
 void led_set(uint8_t usb_led)
 {
+    // need a wait to send command without miss
+    _delay_ms(100);
     adb_host_kbd_led(~usb_led);
 }

converter/adb_usb/matrix.c

@@ -67,6 +67,13 @@ uint8_t matrix_cols(void)
 void matrix_init(void)
 {
     adb_host_init();
+    // wait for keyboard to boot up and receive command
+    _delay_ms(1000);
+    // 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);
 
     // initialize matrix state: all keys off
     for (uint8_t i=0; i < MATRIX_ROWS; i++) matrix[i] = 0x00;

protocol/adb.c

@@ -1,5 +1,6 @@
 /*
 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,
@@ -43,9 +44,11 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "debug.h"
 
 
-static inline void data_lo(void);
+// GCC doesn't inline functions normally
-static inline void data_hi(void);
+#define data_lo() (ADB_DDR |=  (1<<ADB_DATA_BIT))
-static inline bool data_in(void);
+#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);
@@ -56,24 +59,17 @@ static inline void attention(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 uint16_t wait_data_lo(uint16_t us);
-static inline uint8_t read_byte(void);
+static inline uint16_t wait_data_hi(uint16_t us);
-static inline uint8_t wait_data_lo(uint16_t us);
-static inline uint8_t wait_data_hi(uint8_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
@@ -91,128 +87,7 @@ bool adb_host_psw(void)
  * <http://geekhack.org/index.php?topic=14290.msg1068919#msg1068919>
  * <http://geekhack.org/index.php?topic=14290.msg1070139#msg1070139>
  */
-uint16_t adb_host_kbd_recv(void)
-{
-    uint16_t data = 0;
-    attention();
-    send_byte(0x2C);            // Addr:Keyboard(0010), Cmd:Talk(11), Register0(00)
-    place_bit0();               // Stopbit(0)
-    if (!wait_data_lo(500)) {   // Tlt/Stop to Start(140-260us)
-        return 0;               // No data to send
-    }
-    if (!read_bit()) {          // Startbit(1)
-        // Service Request
-        dprintf("Startbit ERROR\n");
-        return -2;
-    }
 
-    // ad hoc fix: without block inerrupt read wrong bit occasionally and get keys stuck
-    cli();
-    data = read_byte();
-    data = (data<<8) | read_byte();
-    uint8_t stop = read_bit();  // Stopbit(0)
-    sei();
-
-    if (stop) {
-        dprintf("Stopbit ERROR\n");
-        return -3;
-    }
-    return data;
-}
-
-void adb_host_listen(uint8_t cmd, uint8_t data_h, uint8_t data_l)
-{
-    attention();
-    send_byte(cmd);
-    place_bit0();               // Stopbit(0)
-    _delay_us(200);             // Tlt/Stop to Start
-    place_bit1();               // Startbit(1)
-    send_byte(data_h); 
-    send_byte(data_l);
-    place_bit0();               // Stopbit(0);
-}
-
-// send state of LEDs
-void adb_host_kbd_led(uint8_t led)
-{
-    // Addr:Keyboard(0010), Cmd:Listen(10), Register2(10)
-    // send upper byte (not used)
-    // send lower byte (bit2: ScrollLock, bit1: CapsLock, bit0:
-    adb_host_listen(0x2A,0,led&0x07);
-}
-
-
-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()
-{
-    ADB_DDR  |=  (1<<ADB_PSW_BIT);
-    ADB_PORT &= ~(1<<ADB_PSW_BIT);
-}
-static inline void psw_hi()
-{
-    ADB_PORT |=  (1<<ADB_PSW_BIT);
-    ADB_DDR  &= ~(1<<ADB_PSW_BIT);
-}
-static inline bool psw_in()
-{
-    ADB_PORT |=  (1<<ADB_PSW_BIT);
-    ADB_DDR  &= ~(1<<ADB_PSW_BIT);
-    return ADB_PIN&(1<<ADB_PSW_BIT);
-}
-#endif
-
-static inline void attention(void)
-{
-    data_lo();
-    _delay_us(700);
-    place_bit1();
-}
-
-static inline void place_bit0(void)
-{
-    data_lo();
-    _delay_us(65);
-    data_hi();
-    _delay_us(35);
-}
-
-static inline void place_bit1(void)
-{
-    data_lo();
-    _delay_us(35);
-    data_hi();
-    _delay_us(65);
-}
-
-static inline void send_byte(uint8_t data)
-{
-    for (int i = 0; i < 8; i++) {
-        if (data&(0x80>>i))
-            place_bit1();
-        else
-            place_bit0();
-    }
-}
-
-static inline bool read_bit(void)
-{
 // ADB Bit Cells
 //
 // bit cell time: 70-130us
@@ -245,47 +120,158 @@ static inline bool read_bit(void)
 //      ______~~~~~~~~~~~~
 //      39-52        78-91
 //
-    // read:
-    //      ________|~~~~~~~~~
-    //              55us
-    // Read data line after 55us. If data line is low/high then bit is 0/1.
-    // This method might not work at <90us bit cell time.
-    //
 // [from Apple IIgs Hardware Reference Second Edition]
-    bool bit;
+
-    wait_data_lo(75);   // wait the start of bit cell at least 130ms(55+0+75)
+uint16_t adb_host_kbd_recv(void)
-    _delay_us(55);
+{
-    bit = data_in();
+    uint16_t data = 0;
-    wait_data_hi(36);   // wait high part of bit cell at least 91ms(55+36)
+    attention();
-    return bit;
+    send_byte(0x2C);            // Addr:Keyboard(0010), Cmd:Talk(11), Register0(00)
+    place_bit0();               // Stopbit(0)
+    if (!wait_data_lo(500)) {   // Tlt/Stop to Start(140-260us)
+        return 0;               // No data to send
     }
     
-static inline uint8_t read_byte(void)
+    // ad hoc fix: without block inerrupt read wrong bit occasionally and get keys stuck
-{
+    // TODO: is this needed anymore with improved timing?
-    uint8_t data = 0;
+    //cli();
-    for (int i = 0; i < 8; i++) {
+    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 (read_bit())
+        if (lo < hi) {
-            data = data | 1;
+            data |= 1;
         }
+        else if (n == 17) {
+            // Service Request
+            dprintf("Startbit ERROR\n");
+            sei();
+            return -2;
+        }
+    }
+    while ( --n );
+
+    // 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)) {
+        dprintf("Stopbit ERROR\n");
+        sei();
+        return -3;
+    }
+    sei();
     return data;
+
+error:
+    dprintf("Bit ERROR\n");
+    sei();
+    return -4;
 }
 
-static inline uint8_t wait_data_lo(uint16_t us)
+void adb_host_listen(uint8_t cmd, uint8_t data_h, uint8_t data_l)
 {
-    while (data_in() && us) {
+    attention();
-        _delay_us(1);
+    send_byte(cmd);
-        us--;
+    place_bit0();               // Stopbit(0)
+    _delay_us(200);             // Tlt/Stop to Start
+    place_bit1();               // Startbit(1)
+    send_byte(data_h); 
+    send_byte(data_l);
+    place_bit0();               // Stopbit(0);
 }
+
+// send state of LEDs
+void adb_host_kbd_led(uint8_t led)
+{
+    // Addr:Keyboard(0010), Cmd:Listen(10), Register2(10)
+    // send upper byte (not used)
+    // send lower byte (bit2: ScrollLock, bit1: CapsLock, bit0:
+    adb_host_listen(0x2A,0,led&0x07);
+}
+
+
+#ifdef ADB_PSW_BIT
+static inline void psw_lo()
+{
+    ADB_DDR  |=  (1<<ADB_PSW_BIT);
+    ADB_PORT &= ~(1<<ADB_PSW_BIT);
+}
+static inline void psw_hi()
+{
+    ADB_PORT |=  (1<<ADB_PSW_BIT);
+    ADB_DDR  &= ~(1<<ADB_PSW_BIT);
+}
+static inline bool psw_in()
+{
+    ADB_PORT |=  (1<<ADB_PSW_BIT);
+    ADB_DDR  &= ~(1<<ADB_PSW_BIT);
+    return ADB_PIN&(1<<ADB_PSW_BIT);
+}
+#endif
+
+static inline void attention(void)
+{
+    data_lo();
+    _delay_us(800-35); // bit1 holds lo for 35 more
+    place_bit1();
+}
+
+static inline void place_bit0(void)
+{
+    data_lo();
+    _delay_us(65);
+    data_hi();
+    _delay_us(35);
+}
+
+static inline void place_bit1(void)
+{
+    data_lo();
+    _delay_us(35);
+    data_hi();
+    _delay_us(65);
+}
+
+static inline void send_byte(uint8_t data)
+{
+    for (int i = 0; i < 8; i++) {
+        if (data&(0x80>>i))
+            place_bit1();
+        else
+            place_bit0();
+    }
+}
+
+// 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)
+{
+    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) {
+    do {
-        _delay_us(1);
+        if ( data_in() )
-        us--;
+            break;
+        _delay_us(1 - (6 * 1000000.0 / F_CPU));
     }
+    while ( --us );
     return us;
 }