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TARGET_NRF5: changed 'sleep()' implementation to the one used in mbedOS 3.

pull/2865/head
Głąbek, Andrzej 2016-09-29 13:24:20 +02:00
parent 2564a833c0
commit 7e8aeadfdc
1 changed files with 44 additions and 2 deletions
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46
hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/sleep.c
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@ -16,13 +16,55 @@
#include "sleep_api.h"
#include "cmsis.h"
#include "mbed_interface.h"
#include "nrf_soc.h"
#include "nrf_sdm.h"
// Mask of reserved bits of the register ICSR in the System Control Block peripheral
// In this case, bits which are equal to 0 are the bits reserved in this register
#define SCB_ICSR_RESERVED_BITS_MASK 0x9E43F03F
void sleep(void)
{
// ensure debug is disconnected if semihost is enabled....
NRF_POWER->TASKS_LOWPWR = 1;
// wait for interrupt
__WFE();
SCB->SCR |= SCB_SCR_SEVONPEND_Msk; /* send an event when an interrupt is pending.
* This helps with the wakeup from the following app_evt_wait(). */
uint8_t sd_enabled;
// look if exceptions are enabled or not, if they are, it is possible to make an SVC call
// and check if the soft device is running
if ((__get_PRIMASK() == 0) && (sd_softdevice_is_enabled(&sd_enabled) == NRF_SUCCESS) && (sd_enabled == 1)) {
// soft device is enabled, use the primitives from the soft device to go to sleep
sd_app_evt_wait();
} else {
// Note: it is not possible to just use WFE at this stage because WFE
// will read the event register (not accessible) and if an event occured,
// in the past, it will just clear the event register and continue execution.
// SVC call like sd_softdevice_is_enabled set the event register to 1.
// This means that a making an SVC call followed by WFE will never put the
// CPU to sleep.
// Our startegy here is to clear the event register then, if there is any
// interrupt, return from here. If no interrupts are pending, just call
// WFE.
// Set an event and wake up whatsoever, this will clear the event
// register from all previous events set (SVC call included)
__SEV();
__WFE();
// Test if there is an interrupt pending (mask reserved regions)
if (SCB->ICSR & (SCB_ICSR_RESERVED_BITS_MASK)) {
// Ok, there is an interrut pending, no need to go to sleep
return;
} else {
// next event will wakeup the CPU
// If an interrupt occured between the test of SCB->ICSR and this
// instruction, WFE will just not put the CPU to sleep
__WFE();
}
}
}
void deepsleep(void)