Initial MakerDiary MDK nrf52840 USB dongle support.

Many TODOs to address but it builds and appears at first glance to work...

src/boards/mdk_nrf52840_dongle.h

@@ -0,0 +1,85 @@
+/**************************************************************************/
+/*!
+    @file     mdk_nrf52840_dongle.h
+    @author   gpshead (krypto.org)
+
+    @section LICENSE
+
+    Software License Agreement (BSD License)
+
+    Copyright (c) 2019, Adafruit Industries (adafruit.com)
+    All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions are met:
+    1. Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+    2. 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.
+    3. Neither the name of the copyright holders nor the
+    names of its 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 ''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 HOLDER 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.
+*/
+/**************************************************************************/
+
+#ifndef _MDK_NRF52840_DONGLE_H_
+#define _MDK_NRF52840_DONGLE_H_
+
+#define _PINNUM(port, pin)    ((port)*32 + (pin))
+
+/*------------------------------------------------------------------*/
+/* LED
+ *------------------------------------------------------------------*/
+// TODO(gpshead): only an rgb led, not a separate primary one.  0?
+#define LEDS_NUMBER           1
+#define LED_PRIMARY_PIN       _PINNUM(0, 23)
+#define LED_STATE_ON          0
+
+#define LED_RGB_RED_PIN       _PINNUM(0, 23)
+#define LED_RGB_GREEN_PIN     _PINNUM(0, 22)
+#define LED_RGB_BLUE_PIN      _PINNUM(0, 24)
+#define BOARD_RGB_BRIGHTNESS  0x202020
+/*------------------------------------------------------------------*/
+/* BUTTON
+ *------------------------------------------------------------------*/
+// TODO(gpshead): simplify, have code support 0.  double reset only.
+#define BUTTONS_NUMBER        2  // none connected at all
+#define BUTTON_1              _PINNUM(0, 18)  // unusable: RESET
+#define BUTTON_2              _PINNUM(0, 19)  // no connection
+#define BUTTON_PULL           NRF_GPIO_PIN_PULLUP
+
+/*------------------------------------------------------------------*/
+/* UART
+ * TODO(gpshead): Does this even make sense to define?
+ * No serial pins.  USB ACM/CDC only.
+ *------------------------------------------------------------------*/
+#define RX_PIN_NUMBER         8
+#define TX_PIN_NUMBER         6
+#define CTS_PIN_NUMBER        0
+#define RTS_PIN_NUMBER        0
+#define HWFC                  false
+
+// Used as model string in OTA mode
+#define DIS_MANUFACTURER      "MakerDiary"
+#define DIS_MODEL             "nRF52840 Micro Dev Kit USB Dongle"
+
+#define PRODUCT_NAME          "MDK nRF52840 USB Dongle"
+#define VOLUME_LABEL          "MDK840DONGL"
+
+#define BOARD_ID "MakerDiary-nRF52840-USB-Dongle"
+
+#define INDEX_URL "https://wiki.makerdiary.com/nrf52840-mdk-usb-dongle/"
+
+#endif /* _MDK_NRF52840_DONGLE_H_ */