blob: 9cbe0a00f9ef9d72639e2252dd12e4bd96290921 [file] [log] [blame]
/*
* Copyright (c) 2016 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <kernel.h>
#include <kernel_structs.h>
/**
*
* @brief Power save idle routine
*
* This function will be called by the kernel idle loop or possibly within
* an implementation of _sys_power_save_idle in the kernel when the
* '_sys_power_save_flag' variable is non-zero.
*
* @return N/A
*/
void k_cpu_idle(void)
{
/* Do nothing but unconditionally unlock interrupts and return to the
* caller. This CPU does not have any kind of power saving instruction.
*/
irq_unlock(NIOS2_STATUS_PIE_MSK);
}
/**
*
* @brief Atomically re-enable interrupts and enter low power mode
*
* INTERNAL
* The requirements for k_cpu_atomic_idle() are as follows:
* 1) The enablement of interrupts and entering a low-power mode needs to be
* atomic, i.e. there should be no period of time where interrupts are
* enabled before the processor enters a low-power mode. See the comments
* in k_lifo_get(), for example, of the race condition that
* occurs if this requirement is not met.
*
* 2) After waking up from the low-power mode, the interrupt lockout state
* must be restored as indicated in the 'imask' input parameter.
*
* @return N/A
*/
void k_cpu_atomic_idle(unsigned int key)
{
/* Do nothing but restore IRQ state. This CPU does not have any
* kind of power saving instruction.
*/
irq_unlock(key);
}