From 9ec861c7e0d4309d9cbdabb29d7e41f9e14216f4 Mon Sep 17 00:00:00 2001
From: Benjamin Gould <bgould@github.com>
Date: Mon, 6 Jan 2014 14:43:59 -0500
Subject: [PATCH] Added NeXT keyboard converter

---
 protocol/next_kbd.c | 204 ++++++++++++++++++++++++++++++++++++++++++++
 protocol/next_kbd.h |  63 ++++++++++++++
 2 files changed, 267 insertions(+)
 create mode 100644 protocol/next_kbd.c
 create mode 100644 protocol/next_kbd.h

diff --git a/protocol/next_kbd.c b/protocol/next_kbd.c
new file mode 100644
index 00000000..a5a07a7a
--- /dev/null
+++ b/protocol/next_kbd.c
@@ -0,0 +1,204 @@
+/*
+
+NeXT non-ADB Keyboard Protocol
+ 
+Copyright 2013, Benjamin Gould (bgould@github.com)
+
+Based on:
+TMK firmware code Copyright 2011,2012 Jun WAKO <wakojun@gmail.com>
+Arduino code by "Ladyada" Limor Fried (http://ladyada.net/, http://adafruit.com/), released under BSD license
+
+Timing reference thanks to http://m0115.web.fc2.com/ (dead link), http://cfile7.uf.tistory.com/image/14448E464F410BF22380BB
+Pinouts thanks to http://www.68k.org/~degs/nextkeyboard.html
+Keycodes from http://ftp.netbsd.org/pub/NetBSD/NetBSD-release-6/src/sys/arch/next68k/dev/
+
+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 <stdint.h>
+#include <stdbool.h>
+#include <util/atomic.h>
+#include <util/delay.h>
+#include "next_kbd.h"
+#include "debug.h"
+
+static inline void out_lo(void);
+static inline void out_hi(void);
+static inline void query(void);
+static inline void reset(void);
+static inline uint32_t response(void);
+
+#define out_hi_delay(intervals)  do { out_hi(); _delay_us(NEXT_KBD_TIMING * intervals); } while (0);
+#define out_lo_delay(intervals)  do { out_lo(); _delay_us(NEXT_KBD_TIMING * intervals); } while (0);
+#define query_delay(intervals)   do { query();  _delay_us(NEXT_KBD_TIMING * intervals); } while (0);
+#define reset_delay(intervals)   do { reset();  _delay_us(NEXT_KBD_TIMING * intervals); } while (0);
+
+void next_kbd_init(void)
+{
+    out_hi();
+    NEXT_KBD_IN_DDR   &= ~(1<<NEXT_KBD_IN_BIT);   // KBD_IN  to input
+    NEXT_KBD_IN_PORT  |=  (1<<NEXT_KBD_IN_BIT);   // KBD_IN  pull up
+    
+    query_delay(5);
+    reset_delay(8);
+    
+    query_delay(5);
+    reset_delay(8);
+}
+
+void next_kbd_set_leds(bool left, bool right)
+{
+    out_lo_delay(9);
+    
+    out_hi_delay(3);
+    out_lo_delay(1);
+    
+    if (left) {
+        out_hi_delay(1);
+    } else {
+        out_lo_delay(1);
+    }
+    
+    if (right) {
+        out_hi_delay(1);
+    } else {
+        out_lo_delay(1);
+    }
+    
+    out_lo_delay(7);
+    out_hi();
+}
+
+#define NEXT_KBD_READ (NEXT_KBD_IN_PIN&(1<<NEXT_KBD_IN_BIT))
+uint32_t next_kbd_recv(void)
+{
+    
+    // First check to make sure that the keyboard is actually connected;
+    // if not, just return
+    // TODO: reflect the status of the keyboard in a return code
+    if (!NEXT_KBD_READ) {
+        sei();
+        return 0;
+    }
+
+    query();
+    uint32_t resp = response();
+    
+    return resp;
+}
+
+static inline uint32_t response(void)
+{
+    cli();
+    
+    // try a 5ms read; this should be called after the query method has
+    // been run so if a key is pressed we should get a response within
+    // 5ms; if not then send a reset and exit
+    uint8_t     i  = 0;
+    uint32_t data  = 0;
+    uint16_t reset_timeout = 50000;
+    while (NEXT_KBD_READ && reset_timeout)  {
+        asm(""); _delay_us(1); reset_timeout--;
+    }
+    if (!reset_timeout) {
+        reset();
+        sei();
+        return 0;
+    }
+    _delay_us(NEXT_KBD_TIMING / 2);
+    for (; i < 22; i++)
+    {
+        if (NEXT_KBD_READ)
+        {
+            data |= ((uint32_t) 1 << i);
+            /* Note:
+             * My testing with the ATmega32u4 showed that there might
+             * something wrong with the timing here; by the end of the
+             * second data byte some of the modifiers can get bumped out
+             * to the next bit over if we just cycle through the data
+             * based on the expected interval.  There is a bit (i = 10) 
+             * in the middle of the data that is always on followed by 
+             * one that is always off - so we'll use that to reset our 
+             * timing in case we've gotten ahead of the keyboard;
+             */
+            if (i == 10)
+            {
+                i++;
+                while (NEXT_KBD_READ) ;
+                _delay_us(NEXT_KBD_TIMING / 2);
+            }
+        } else {
+            /* redundant - but I don't want to remove if it might screw
+             * up the timing
+             */
+            data |= ((uint32_t) 0 << i);
+        }
+        _delay_us(NEXT_KBD_TIMING);
+    }
+    
+    sei();
+    
+    return data;
+}
+
+static inline void out_lo(void)
+{
+    NEXT_KBD_OUT_PORT &= ~(1<<NEXT_KBD_OUT_BIT);
+    NEXT_KBD_OUT_DDR  |=  (1<<NEXT_KBD_OUT_BIT);
+}
+
+static inline void out_hi(void)
+{
+    /* input with pull up */
+    NEXT_KBD_OUT_DDR  &= ~(1<<NEXT_KBD_OUT_BIT);
+    NEXT_KBD_OUT_PORT |=  (1<<NEXT_KBD_OUT_BIT);
+}
+
+static inline void query(void)
+{
+    out_lo_delay(5);
+    out_hi_delay(1);
+    out_lo_delay(3);
+    out_hi();
+}
+
+static inline void reset(void)
+{
+    out_lo_delay(1);
+    out_hi_delay(4);
+    out_lo_delay(1);
+    out_hi_delay(6);
+    out_lo_delay(10);
+    out_hi();
+}
diff --git a/protocol/next_kbd.h b/protocol/next_kbd.h
new file mode 100644
index 00000000..6d455d4f
--- /dev/null
+++ b/protocol/next_kbd.h
@@ -0,0 +1,63 @@
+/*
+NeXT non-ADB Keyboard Protocol
+ 
+Copyright 2013, Benjamin Gould (bgould@github.com)
+
+Based on:
+TMK firmware code Copyright 2011,2012 Jun WAKO <wakojun@gmail.com>
+Arduino code by "Ladyada" Limor Fried (http://ladyada.net/, http://adafruit.com/), released under BSD license
+
+Timing reference thanks to http://m0115.web.fc2.com/ (dead link), http://cfile7.uf.tistory.com/image/14448E464F410BF22380BB
+Pinouts thanks to http://www.68k.org/~degs/nextkeyboard.html
+Keycodes from http://ftp.netbsd.org/pub/NetBSD/NetBSD-release-6/src/sys/arch/next68k/dev/
+
+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>
+
+#ifndef NEXT_KBD_H
+#define NEXT_KBD_H
+
+#define NEXT_KBD_KMBUS_IDLE 0x300600
+#define NEXT_KBD_TIMING     50
+
+extern uint8_t next_kbd_error;
+
+/* host role */
+void next_kbd_init(void);
+void next_kbd_set_leds(bool left, bool right);
+uint32_t next_kbd_recv(void);
+
+#endif