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, 118 insertions, 0 deletions

diff --git a/tmk_core/protocol/arm_atsam/usb/main_usb.c b/tmk_core/protocol/arm_atsam/usb/main_usb.c
new file mode 100644
index 0000000000..e943cbcdcd
--- /dev/null
+++ b/tmk_core/protocol/arm_atsam/usb/main_usb.c
@@ -0,0 +1,118 @@
+/*
+Copyright 2018 Massdrop Inc.
+
+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/>.
+*/
+
+#include "samd51j18a.h"
+#include "conf_usb.h"
+#include "udd.h"
+
+uint8_t keyboard_protocol = 1;
+
+void main_suspend_action(void)
+{
+    ui_powerdown();
+}
+
+void main_resume_action(void)
+{
+    ui_wakeup();
+}
+
+void main_sof_action(void)
+{
+    ui_process(udd_get_frame_number());
+}
+
+void main_remotewakeup_enable(void)
+{
+    ui_wakeup_enable();
+}
+
+void main_remotewakeup_disable(void)
+{
+    ui_wakeup_disable();
+}
+
+#ifdef KBD
+volatile bool main_b_kbd_enable = false;
+bool main_kbd_enable(void)
+{
+    main_b_kbd_enable = true;
+    return true;
+}
+
+void main_kbd_disable(void)
+{
+    main_b_kbd_enable = false;
+}
+#endif
+
+#ifdef NKRO
+volatile bool main_b_nkro_enable = false;
+bool main_nkro_enable(void)
+{
+    main_b_nkro_enable = true;
+    return true;
+}
+
+void main_nkro_disable(void)
+{
+    main_b_nkro_enable = false;
+}
+#endif
+
+#ifdef EXK
+volatile bool main_b_exk_enable = false;
+bool main_exk_enable(void)
+{
+    main_b_exk_enable = true;
+    return true;
+}
+
+void main_exk_disable(void)
+{
+    main_b_exk_enable = false;
+}
+#endif
+
+#ifdef MOU
+volatile bool main_b_mou_enable = false;
+bool main_mou_enable(void)
+{
+    main_b_mou_enable = true;
+    return true;
+}
+
+void main_mou_disable(void)
+{
+    main_b_mou_enable = false;
+}
+#endif
+
+#ifdef RAW
+volatile bool main_b_raw_enable = false;
+bool main_raw_enable(void)
+{
+    main_b_raw_enable = true;
+    return true;
+}
+
+void main_raw_disable(void)
+{
+    main_b_raw_enable = false;
+}
+#endif
+