/****************************************************************************

*

* Copyright 2024 Samsung Electronics All Rights Reserved.

*

* 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.

*

****************************************************************************/

/****************************************************************************

* Included Files

****************************************************************************/

#include <tinyara/config.h>

#include <assert.h>

#include <tinyara/pm/pm.h>

#include <tinyara/clock.h>

#include <tinyara/irq.h>

#include <tinyara/arch.h>

#include "../kernel/sched/sched.h"

#include "pm.h"

#ifdef CONFIG_SMP

#include "../arch/arm/src/armv7-a/smp.h"

#endif

#ifdef CONFIG_PM

/****************************************************************************

* Pre-processor Definitions

****************************************************************************/

/****************************************************************************

* Private Variables

****************************************************************************/

static clock_t stime;

/****************************************************************************

* Private Functions

****************************************************************************/

/****************************************************************************

* Public Functions

****************************************************************************/

/****************************************************************************

* Name: pm_idle

*

* Description:

* This function is called by IDLE thread to make board sleep. This function

* also allow to set wake up timer & handler and do all the PM pre processing

* required before going to sleep.

*

* Input Parameters:

* None

*

* Returned Value:

* None

*

****************************************************************************/

void pm_idle(void)

{

irqstate_t flags;

enum pm_state_e newstate;

clock_t now;

#ifdef CONFIG_PM_TIMEDWAKEUP

clock_t delay = 0;

#endif

#ifdef CONFIG_SMP

int cpu;

int gated_cpu_count = 0;

FAR struct tcb_s *tcb;

#endif

/* State change only if PM is ready to state change */

if (!g_pmglobals.is_running) {

return;

}

flags = enter_critical_section();

sched_lock();

now = clock_systimer();

/* We need to check and change PM state transition only if one tick time has been passed,

* because state transition only happens when CPU receive TICK INTERRUPT. So checking pm state

* multiple times within one tick is waste of CPU clocks and we should avoid it.

*/

if (now > stime) {

stime = now;

/* Decide, which power saving level can be obtained */

newstate = pm_checkstate();

#ifdef CONFIG_PM_METRICS

pm_metrics_update_idle();

#endif

#ifdef CONFIG_PM_TIMEDWAKEUP

/* get wakeup timer */

if (newstate == PM_SLEEP) {

delay = wd_getwakeupdelay();

if ((delay > 0) && (delay < MSEC2TICK(CONFIG_PM_SLEEP_ENTRY_WAIT_MS))) {

pmvdbg("Wdog Timer Delay: %ldms is less than SLEEP_ENTRY_WAIT: %ldms\n", TICK2MSEC(delay), CONFIG_PM_SLEEP_ENTRY_WAIT_MS);

goto EXIT;

}

}

#endif

/* Perform state-dependent logic here */

/* For SMP case, we need to check secondary core status

* If secondary core status is not in idle thread, abort

* the sleep and check again on next cycle

*/

#ifdef CONFIG_SMP

if (newstate == PM_SLEEP) {

for (cpu = 1; cpu < CONFIG_SMP_NCPUS; cpu++) {

/* If the CPU is just back from sleep, abort the sleep */

if (up_get_cpu_state(cpu) == CPU_WAKE_FROM_SLEEP) {

goto EXIT;

} else if (up_get_cpu_state(cpu) == CPU_HOTPLUG) {

continue;

}

/* Gate the cpu first, before checking which task it is handling */

if (!up_get_gating_flag_status(cpu)) {

up_set_gating_flag_status(cpu, 1);

up_cpu_gating(cpu);

gated_cpu_count = cpu;

}

while (up_get_gating_flag_status(cpu) == 1) {

/* If there is a pause request, we should handle it first */

if (up_cpu_pausereq(up_cpu_index())) {

pmdbg("Sleep abort! CPU%d\n", cpu);

goto EXIT;

}

}

tcb = current_task(cpu);

/* Check if current cpu is in idle thread, and whether there is pending

* pause request on primary core

*/

if (tcb->pid != cpu) {

pmvdbg("Sleep abort! CPU%d task: %s!\n", cpu, tcb->name);

goto EXIT;

}

}

}

#endif

/* Then force the global state change */

if (pm_changestate(newstate) < 0) {

/* The new state change failed */

pmdbg("State change failed! newstate = %d\n", newstate);

goto EXIT;

}

/* If current state is not good to go sleep then do core power saving*/

if (g_pmglobals.state != PM_SLEEP) {

goto EXIT;

}

#ifdef CONFIG_SMP

/* Send signal to shutdown other cores here */

for (cpu = 1; cpu < CONFIG_SMP_NCPUS; cpu++) {

if (up_get_cpu_state(cpu) == CPU_RUNNING) {

up_cpu_hotplug(cpu);

}

/* Reset core gating status flag */

up_set_gating_flag_status(cpu, 0);

/* Check whether each of the cpu has entered hotplug */

while (up_get_cpu_state(cpu) != CPU_HOTPLUG);

}

gated_cpu_count = 0;

#endif

#ifdef CONFIG_PM_TIMEDWAKEUP

/* set wakeup timer */

if (delay > 0) {

pmvdbg("Setting timer and board will wake up after %ld millisecond\n", delay);

up_set_pm_timer(TICK2USEC(delay));

}

#endif

up_pm_board_sleep(pm_wakehandler);

stime = clock_systimer();

}

EXIT:

#ifdef CONFIG_SMP

/* Check if any core is gated, resume it */

while (gated_cpu_count) {

up_set_gating_flag_status(gated_cpu_count, 0);

gated_cpu_count--;

}

#endif

sched_unlock();

leave_critical_section(flags);

}

#endif /* CONFIG_PM */