zephyr/kernel/nanokernel/idle.c

93 lines
2.2 KiB
C

/*
* Copyright (c) 2011-2014 Wind River Systems, Inc.
*
* 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.
*/
/**
* @file
* @brief Nanokernel idle support
*
* This module provides routines to set the idle field in the nanokernel
* data structure.
*/
#include <nanokernel.h>
#include <nano_private.h>
#include <toolchain.h>
#include <sections.h>
#include <drivers/system_timer.h>
#include <wait_q.h>
/**
*
* @brief Indicate that nanokernel is idling in tickless mode
*
* Sets the nanokernel data structure idle field to a non-zero value.
*
* @param ticks the number of ticks to idle
*
* @return N/A
*/
void nano_cpu_set_idle(int32_t ticks)
{
extern tNANO _nanokernel;
_nanokernel.idle = ticks;
}
#if defined(CONFIG_NANOKERNEL) && defined(CONFIG_TICKLESS_IDLE)
int32_t _sys_idle_ticks_threshold = CONFIG_TICKLESS_IDLE_THRESH;
#if defined(CONFIG_NANO_TIMEOUTS) || defined(CONFIG_NANO_TIMERS)
static inline int32_t get_next_tick_expiry(void)
{
return _nano_get_earliest_timeouts_deadline();
}
#else
#define get_next_tick_expiry(void) TICKS_UNLIMITED
#endif
static inline int was_in_tickless_idle(void)
{
return (_nanokernel.idle == TICKS_UNLIMITED) ||
(_nanokernel.idle >= _sys_idle_ticks_threshold);
}
static inline int must_enter_tickless_idle(void)
{
/* uses same logic as was_in_tickless_idle() */
return was_in_tickless_idle();
}
void _power_save_idle(void)
{
_nanokernel.idle = get_next_tick_expiry();
if (must_enter_tickless_idle()) {
_timer_idle_enter((uint32_t)_nanokernel.idle);
}
}
void _power_save_idle_exit(void)
{
if (was_in_tickless_idle()) {
_timer_idle_exit();
_nanokernel.idle = 0;
}
}
#endif /* CONFIG_NANOKERNEL && CONFIG_TICKLESS_IDLE */