[WIP] initial API design

samd basic functions ported

src/ArduinoLowPower.cpp

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+#include "ArduinoLowPower.h"
+
+#ifdef ARDUINO_ARCH_SAMD
+
+#include "WInterrupts.h"
+
+void ArduinoLowPowerClass::idle() {
+	SCB->SCR &= ~SCB_SCR_SLEEPDEEP_Msk;
+	PM->SLEEP.reg = 2;
+	__DSB();
+	__WFI();
+}
+
+void ArduinoLowPowerClass::idle(uint32_t millis) {
+	setAlarmIn(millis);
+	idle();
+}
+
+void ArduinoLowPowerClass::sleep() {
+	SCB->SCR |= SCB_SCR_SLEEPDEEP_Msk;
+	__DSB();
+	__WFI();
+}
+
+void ArduinoLowPowerClass::sleep(uint32_t millis) {
+	setAlarmIn(millis);
+	sleep();
+}
+
+void ArduinoLowPowerClass::deepSleep() {
+	sleep();
+}
+
+void ArduinoLowPowerClass::deepSleep(uint32_t millis) {
+	sleep(millis);
+}
+
+void ArduinoLowPowerClass::setAlarmIn(uint32_t millis) {
+
+	if (!rtc.isConfigured()) {
+		attachInterruptWakeup(RTC_ALARM_WAKEUP, NULL, 0);
+	}
+
+	uint32_t now = rtc.getEpoch();
+	rtc.setAlarmEpoch(now + millis/1000);
+	rtc.enableAlarm(rtc.MATCH_YYMMDDHHMMSS);
+}
+
+void ArduinoLowPowerClass::attachInterruptWakeup(uint32_t pin, voidFuncPtr callback, uint32_t mode) {
+
+	if (pin > PINS_COUNT) {
+		// check for external wakeup sources
+		// only enables the wakeup bit, no callback
+		// RTC library should call this API to enable the alarm subsystem
+		switch (pin) {
+			case RTC_ALARM_WAKEUP:
+				rtc.begin();
+				rtc.attachInterrupt(callback);
+			/*case UART_WAKEUP:*/
+		}
+		return;
+	}
+
+	EExt_Interrupts in = g_APinDescription[pin].ulExtInt;
+	if (in == NOT_AN_INTERRUPT || in == EXTERNAL_INT_NMI)
+    		return;
+
+	attachInterrupt(pin, callback, mode);
+
+#if 0
+	// enable EIC clock
+	GCLK->CLKCTRL.bit.CLKEN = 0; //disable GCLK module
+	while (GCLK->STATUS.bit.SYNCBUSY);
+
+	GCLK->CLKCTRL.reg = (uint16_t) (GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN_GCLK6 | GCLK_CLKCTRL_ID( GCM_EIC )) ;  //EIC clock switched on GCLK6
+	while (GCLK->STATUS.bit.SYNCBUSY);
+
+	GCLK->GENCTRL.reg = (GCLK_GENCTRL_GENEN | GCLK_GENCTRL_SRC_OSCULP32K | GCLK_GENCTRL_ID(6));  //source for GCLK6 is OSCULP32K
+	while (GCLK->STATUS.reg & GCLK_STATUS_SYNCBUSY);
+
+	GCLK->GENCTRL.bit.RUNSTDBY = 1;  //GCLK6 run standby
+	while (GCLK->STATUS.reg & GCLK_STATUS_SYNCBUSY);
+#endif
+
+	// Enable wakeup capability on pin in case being used during sleep
+	EIC->WAKEUP.reg |= (1 << in);
+
+	/* Errata: Make sure that the Flash does not power all the way down
+     	* when in sleep mode. */
+	NVMCTRL->CTRLB.bit.SLEEPPRM = NVMCTRL_CTRLB_SLEEPPRM_DISABLED_Val;
+}
+
+#endif
+
+ArduinoLowPowerClass LowPower;

src/ArduinoLowPower.h

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+#ifndef _ARDUINO_LOW_POWER_H_
+#define _ARDUINO_LOW_POWER_H_
+
+#include <Arduino.h>
+
+#ifdef ARDUINO_ARCH_SAMD
+#include "RTCZero.h"
+#endif
+
+//typedef void (*voidFuncPtr)( void ) ;
+
+class ArduinoLowPowerClass {
+	public:
+		void idle(void);
+		void idle(uint32_t millis);
+
+		void sleep(void);
+		void sleep(uint32_t millis);
+
+		void deepSleep(void);
+		void deepSleep(uint32_t millis);
+
+		void attachInterruptWakeup(uint32_t pin, voidFuncPtr callback, uint32_t mode);
+
+	private:
+		#ifdef ARDUINO_ARCH_SAMD
+		void setAlarmIn(uint32_t millis);
+		RTCZero rtc;
+		#define RTC_ALARM_WAKEUP	0xFF
+		#endif
+};
+
+extern ArduinoLowPowerClass LowPower;
+
+#endif