Massdrop keyboard support (#3780)

* Massdrop SAMD51

Massdrop SAMD51 keyboards initial project upload

* Removing relocated files

Removing files that were relocated and not deleted from previous location

* LED queue fix and cleaning

Cleaned some white space or comments.
Fix for LED I2C command queue.
Cleaned up interrupts.
Added debug function for printing numbers to scope through m15 line.

* Factory programmed serial usage

Ability to use factory programmed serial in hub and keyboard usb descriptors

* USB serial number and bugfix

Added support for factory programmed serial and usage.
Incorporated bootloader's conditional compiling to align project closer.
Fixed issue when USB device attempted to send before enabled.
General white space and comment cleanup.

* Project cleanup

Cleaned up project in terms of white space, commented code, and unecessary files.
NKRO keyboard is now using correct setreport although KBD was fine to use.
Fixed broken linkage to __xprintf for serial debug statements.

* Fix for extra keys

Fixed possible USB hang on extra keys report set missing

* I2C cleanup

I2C cleanup and file renames necessary for master branch merge

* Boot tracing and clocks cleanup

Added optional boot debug trace mode through debug LED codes.
General clock code cleanup.

* Relocate ARM/Atmel headers

Moved ARM/Atmel header folder from drivers to lib and made necessary makefile changes.

* Pull request changes

Pull request changes

* Keymap and compile flag fix

Keymap fix for momentary layer.
Potential compile flag fix for Travis CI failure.

* va_list include fix

Fix for va_list compile failure

* Include file case fixes

Fixes for include files with incorrect case

* ctrl and alt67 keyboard readme

Added ctrl and alt67 keyboard readme files

1 files changed, 79 insertions, 0 deletions

diff --git a/keyboards/alt67/config.h b/keyboards/alt67/config.h
new file mode 100644
index 000000000..c67ae7d43
--- /dev/null
+++ b/keyboards/alt67/config.h
@@ -0,0 +1,79 @@
+/*
+Copyright 2015 Jun Wako <wakojun@gmail.com>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#pragma once
+
+#include "config_common.h"
+
+/* USB Device descriptor parameter */
+#define VENDOR_ID           0x04D8
+#define PRODUCT_ID          0xEED3
+#define DEVICE_VER          0x0101
+
+#define MANUFACTURER        "Massdrop Inc."
+#define PRODUCT             "ALT67 Keyboard"
+#define SERIAL_NUM          "Unavailable"
+
+/* key matrix size */
+#define MATRIX_ROWS 5
+#define MATRIX_COLS 15
+
+#define PA 0
+#define PB 1
+
+#define MATRIX_ROW_PORTS PA, PA, PA, PA, PA
+#define MATRIX_ROW_PINS   0,  1,  2,  3,  4
+
+#define MATRIX_COL_PORTS PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, PA, PA, PA, PA, PA
+#define MATRIX_COL_PINS   4,  5,  6,  7,  8,  9, 10, 11, 12, 13,  5,  6,  7, 10, 11
+
+/* Print boot debug codes using debug LED when M28 and M30 shorted */
+#define DEBUG_BOOT_TRACING
+
+/* Debounce reduces chatter (unintended double-presses) - set 0 if debouncing is not needed */
+#define DEBOUNCING_DELAY 5
+
+/* Mechanical locking support. Use KC_LCAP, KC_LNUM or KC_LSCR instead in keymap */
+//#define LOCKING_SUPPORT_ENABLE
+/* Locking resynchronize hack */
+//#define LOCKING_RESYNC_ENABLE
+
+/* key combination for command */
+#define IS_COMMAND() ( \
+    keyboard_report->mods == (MOD_BIT(KC_LSHIFT) | MOD_BIT(KC_RSHIFT)) \
+)
+
+/* Force boot in NKRO mode */
+//#define FORCE_NKRO
+
+/*
+ * Feature disable options
+ *  These options are also useful to firmware size reduction.
+ */
+
+/* disable debug print */
+//#define NO_DEBUG
+
+/* disable print */
+//#define NO_PRINT
+
+/* disable action features */
+//#define NO_ACTION_LAYER
+//#define NO_ACTION_TAPPING
+//#define NO_ACTION_ONESHOT
+//#define NO_ACTION_MACRO
+//#define NO_ACTION_FUNCTION