File content as of revision 525:c320967f86b9:

/* mbed Microcontroller Library
 * Copyright (c) 2006-2013 ARM Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "device.h"
#if DEVICE_SLEEP

#include "sleep_api.h"
#include "cmsis.h"
#include "em_emu.h"
#include "em_int.h"

uint32_t sleep_block_counter[NUM_SLEEP_MODES] = {0};

/**
 * Sleep mode.
 * Enter Energy Mode 1, which turns off the clock to the CPU.
 *
 * In EM1, the CPU is sleeping and the power consumption is only 50 μA/MHz.
 * All peripherals, including DMA, PRS and memory system, are still available.
 */
void sleep(void)
{
	if (sleep_block_counter[0] > 0) {
		// Blocked everything below EM0, so just return
		return;
	} else if (sleep_block_counter[1] > 0) {
		// Blocked everything below EM1, enter EM1
		EMU_EnterEM1();
	} else if (sleep_block_counter[2] > 0) {
		// Blocked everything below EM2, enter EM2
		EMU_EnterEM2(true);
	} else if (sleep_block_counter[3] > 0) {
		// Blocked everything below EM3, enter EM3
		EMU_EnterEM3(true);
	}
    return;
}

/**
 * Deep Sleep mode.
 * Enter Energy Mode 2, turning off all high-frequency clocks.
 *
 * In EM2 the high frequency oscillator is turned off, but with the 32.768 kHz
 * oscillator running, selected low energy peripherals (LCD, RTC, LETIMER,
 * PCNT, LEUART, I2C, LESENSE, OPAMP, USB, WDOG and ACMP) are still
 * available. This gives a high degree of autonomous operation with a current
 * consumption as low as 1.1 μA with RTC enabled. Power-on Reset, Brown-out
 * Detection and full RAM and CPU retention is also included.
 */
void deepsleep(void)
{
    EMU_EnterEM2(true);
}

/** Block the microcontroller from sleeping below a certain mode
 *
 * This will block sleep() from entering an energy mode below the one given.
 * -- To be called by peripheral HAL's --
 *
 * After the peripheral is finished with the operation, it should call unblock with the same state
 *
 */
void blockSleepMode(sleepstate_enum minimumMode) 
{
	INT_Disable();
	sleep_block_counter[minimumMode]++;
	INT_Enable();
}

/** Unblock the microcontroller from sleeping below a certain mode
 *
 * This will unblock sleep() from entering an energy mode below the one given.
 * -- To be called by peripheral HAL's --
 *
 * This should be called after all transactions on a peripheral are done.
 */
void unblockSleepMode(sleepstate_enum minimumMode) 
{
	INT_Disable();
	if(sleep_block_counter[minimumMode] > 0) 
	{
		sleep_block_counter[minimumMode]--;
	}
	INT_Enable();
}

#endif