X-Git-Url: https://git.friedersdorff.com/?a=blobdiff_plain;ds=sidebyside;f=tmk_core%2Fprotocol%2Fadb.c;h=3600595121ce1b606e5ba66eeb08026a393842a7;hb=c09600b56b80538abacb31435c3628ff579428c8;hp=7feffb30e62244f378df525dce0d1350b5e3255d;hpb=814eaa2dffa10f8b3a9f5c5ae6fab430322056d7;p=max%2Ftmk_keyboard.git

diff --git a/tmk_core/protocol/adb.c b/tmk_core/protocol/adb.c
index 7feffb30..36005951 100644
--- a/tmk_core/protocol/adb.c
+++ b/tmk_core/protocol/adb.c
@@ -1,5 +1,5 @@
 /*
-Copyright 2011 Jun WAKO <wakojun@gmail.com>
+Copyright 2011-19 Jun WAKO <wakojun@gmail.com>
 Copyright 2013 Shay Green <gblargg@gmail.com>
 
 This software is licensed with a Modified BSD License.
@@ -113,18 +113,71 @@ uint8_t adb_host_talk_buf(uint8_t addr, uint8_t reg, uint8_t *buf, uint8_t len)
     attention();
     send_byte((addr<<4) | ADB_CMD_TALK | reg);
     place_bit0();               // Stopbit(0)
+    // TODO: Service Request(Srq):
+    // Device holds low part of comannd stopbit for 140-260us
+    //
+    // Command:
+    // ......._     ______________________    ___ ............_     -------
+    //         |   |                      |  |   |             |   |
+    // Command |   |                      |  |   | Data bytes  |   |
+    // ........|___|  |     140-260       |__|   |_............|___|
+    //         |stop0 | Tlt Stop-to-Start |start1|             |stop0 |
+    //
+    // Command without data:
+    // ......._     __________________________
+    //         |   |
+    // Command |   |
+    // ........|___|  |     140-260       |
+    //         |stop0 | Tlt Stop-to-Start |
+    //
+    // Service Request:
+    // ......._                     ______    ___ ............_     -------
+    //         |     140-260       |      |  |   |             |   |
+    // Command |  Service Request  |      |  |   | Data bytes  |   |
+    // ........|___________________|      |__|   |_............|___|
+    //         |stop0 |                   |start1|             |stop0 |
+    // ......._                     __________
+    //         |     140-260       |
+    // Command |  Service Request  |
+    // ........|___________________|
+    //         |stop0 |
+    // This can be happened?
+    // ......._     ______________________    ___ ............_                   -----
+    //         |   |                      |  |   |             |    140-260      |
+    // Command |   |                      |  |   | Data bytes  | Service Request |
+    // ........|___|  |     140-260       |__|   |_............|_________________|
+    //         |stop0 | Tlt Stop-to-Start |start1|             |stop0 |
+    //
+    // "Service requests are issued by the devices during a very specific time at the
+    // end of the reception of the command packet.
+    // If a device in need of service issues a service request, it must do so within
+    // the 65 µs of the Stop Bit’s low time and maintain the line low for a total of 300 µs."
+    //
+    // "A device sends a Service Request signal by holding the bus low during the low
+    // portion of the stop bit of any command or data transaction. The device must lengthen
+    // the stop by a minimum of 140 J.lS beyond its normal duration, as shown in Figure 8-15."
+    // http://ww1.microchip.com/downloads/en/AppNotes/00591b.pdf
     if (!wait_data_hi(500)) {    // Service Request(310us Adjustable Keyboard): just ignored
+        xprintf("R");
         sei();
-        return -30;             // something wrong
+        return 0;
     }
     if (!wait_data_lo(500)) {   // Tlt/Stop to Start(140-260us)
         sei();
-        return 0;               // No data to send
+        return 0;               // No data from device(not error);
     }
 
     // start bit(1)
-    if (!wait_data_hi(40)) return 0;
-    if (!wait_data_lo(100)) return 0;
+    if (!wait_data_hi(40)) {
+        xprintf("S");
+        sei();
+        return 0;
+    }
+    if (!wait_data_lo(100)) {
+        xprintf("s");
+        sei();
+        return 0;
+    }
 
     uint8_t n = 0; // bit count
     do {
@@ -143,7 +196,7 @@ uint8_t adb_host_talk_buf(uint8_t addr, uint8_t reg, uint8_t *buf, uint8_t len)
 
         uint8_t hi = (uint8_t) wait_data_lo(lo);
         if (!hi)
-            goto error; // stop bit extedned by Srq
+            goto error; // stop bit extedned by Srq?
 
         if (n/8 >= len) continue; // can't store in buf
 
@@ -174,6 +227,7 @@ void adb_host_listen_buf(uint8_t addr, uint8_t reg, uint8_t *buf, uint8_t len)
     attention();
     send_byte((addr<<4) | ADB_CMD_LISTEN | reg);
     place_bit0();               // Stopbit(0)
+    // TODO: Service Request
     _delay_us(200);             // Tlt/Stop to Start
     place_bit1();               // Startbit(1)
     for (int8_t i = 0; i < len; i++) {