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, 90 insertions, 0 deletions

diff --git a/tmk_core/protocol/arm_atsam/clks.h b/tmk_core/protocol/arm_atsam/clks.h
new file mode 100644
index 000000000..96819bfdd
--- /dev/null
+++ b/tmk_core/protocol/arm_atsam/clks.h
@@ -0,0 +1,90 @@
+/*
+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/>.
+*/
+
+#ifndef _CLKS_H_
+#define _CLKS_H_
+
+#ifndef MD_BOOTLOADER
+
+//From keyboard
+#include "config_led.h"
+#include "config.h"
+
+#endif //MD_BOOTLOADER
+
+#define PLL_RATIO                   47  //mcu frequency ((X+1)MHz)
+#define FREQ_DFLL_DEFAULT     48000000  //DFLL frequency / usb clock
+#define FREQ_SPI_DEFAULT       1000000  //spi to 595 shift regs
+#define FREQ_I2C0_DEFAULT       100000  //i2c to hub
+#define FREQ_I2C1_DEFAULT       I2C_HZ  //i2c to LED drivers
+#define FREQ_TC45_DEFAULT      1000000  //1 usec resolution
+
+//I2C1 Set      ~Result     PWM Time (2x Drivers)
+//     1000000  1090000
+//     900000   1000000     3.82ms
+//     800000   860000
+//     700000   750000
+//     600000   630000
+//     580000   615000      6.08ms
+//     500000   522000
+
+#define FREQ_XOSC0            16000000
+
+#define CHAN_SERCOM_SPI   2 //shift regs
+#define CHAN_SERCOM_I2C0  0 //hub
+#define CHAN_SERCOM_I2C1  1 //led drivers
+#define CHAN_SERCOM_UART  3 //debug util
+
+//Generator clock channels
+#define GEN_DPLL0   0
+#define GEN_OSC0    1
+#define GEN_TC45    2
+
+#define SERCOM_COUNT 5
+#define GCLK_COUNT  12
+
+typedef struct clk_s {
+    uint32_t freq_dfll;
+    uint32_t freq_dpll[2];
+    uint32_t freq_sercom[SERCOM_COUNT];
+    uint32_t freq_gclk[GCLK_COUNT];
+    uint32_t freq_xosc0;
+    uint32_t freq_spi;
+    uint32_t freq_i2c0;
+    uint32_t freq_i2c1;
+    uint32_t freq_uart;
+    uint32_t freq_adc0;
+} clk_t;
+
+extern volatile clk_t system_clks;
+extern volatile uint64_t ms_clk;
+
+void CLK_oscctrl_init(void);
+void CLK_reset_time(void);
+uint32_t CLK_set_gclk_freq(uint8_t gclkn, uint32_t freq);
+uint32_t CLK_enable_timebase(void);
+uint32_t CLK_get_ms(void);
+uint64_t CLK_get_us(void);
+void CLK_delay_us(uint16_t usec);
+void CLK_delay_ms(uint64_t msec);
+
+uint32_t CLK_set_spi_freq(uint8_t sercomn, uint32_t freq);
+uint32_t CLK_set_i2c0_freq(uint8_t sercomn, uint32_t freq);
+uint32_t CLK_set_i2c1_freq(uint8_t sercomn, uint32_t freq);
+void CLK_init(void);
+
+#endif // _CLKS_H_