Low Power Mode Debugging Guide

Chip Power Domains

There are three internal power domains: AON, MCU, and Main. The AON is a power domain that must remain powered at all times as it cannot be powered off. The MCU power domain supplies power to the Hsm, MCU, and their internal IPs. The Main domain supplies power to the other parts.

Power State List

Five power states are currently implemented: Off, MCU only, Working, Deep sleep, and Light sleep. Detailed descriptions are as follows:

Power State	Description	AON	MCU	Main	DDR颗粒
Off	Chip completely powered off	Off	Off	Off	Off
MCU only	MCU Rcore working normally	On	On	Off	Off
Deep sleep	Only AON working, wakeable	On	Off	Off	Self-refresh
Working	Normal working mode	On	On	On	On
Light sleep	MCU working normally, Main only supplies DDR self-refresh	On	On	Off	Self-refresh

Sleep and Wakeup

warning

Note: The wakeup source APIs and commands described below, as well as the wakeup APIs and commands for Light sleep mode, can only be called within MCU0.

Setting Sleep Mode

The default sleep mode is Deep sleep mode.

Display Currently Supported Sleep Modes

root@ubuntu:~# cat /sys/devices/platform/suspend-mode/suspend_mode/suspend_mode
light deep

Currently supported sleep modes are deep and light, with deep being the default.

Display Current Sleep Mode

root@ubuntu:~# cat /sys/devices/platform/suspend-mode/suspend_mode/current_suspend_mode
deep

Switch Sleep Mode

root@ubuntu:~# cat /sys/devices/platform/suspend-mode/suspend_mode/current_suspend_mode
deep
root@ubuntu:~# echo light > /sys/devices/platform/suspend-mode/suspend_mode/suspend_mode
root@ubuntu:~# cat /sys/devices/platform/suspend-mode/suspend_mode/current_suspend_mode
light

Setting Wakeup Source

The default wakeup source is RTC, with a time of 15 seconds.

The default wakeup source is RTC, with a time of 10 seconds.

Setting Wakeup Source via MCU Command

D-Robotics:/$ wakeupsource
[01504.149120 0]WakeupSource Usage:
[01504.149349 0]    WakeupSource rtc <time(seconds)>
[01504.149935 0]    WakeupSource can
[01504.150347 0]    WakeupSource gpio <gpio_index> <type> <level>
[01504.151093 0]        type:  0:level other:edge
[01504.151628 0]        level: 0:low   other:high

Currently, only RTC and GPIO are supported as wakeup sources. Examples are as follows:

Set RTC as the wakeup source with a time of 60 seconds

D-Robotics:/$ wakeupsource rtc 60
[01620.452562 0]rtc init alarm time 60.
Return: 0, 0x00000000

Set GPIO as the wakeup source, AON GPIO 11, active low

D-Robotics:/$ wakeupsource gpio 11 0 0
[01680.254419 0]set gpio wakeup source with index 11 type 0 level 0.
Return: 0, 0x00000000

Set GPIO as the wakeup source, AON GPIO 8, active low

D-Robotics:/$ wakeupsource gpio 8 0 0
[01680.254419 0]set gpio wakeup source with index 8 type 0 level 0.
Return: 0, 0x00000000

Setting Wakeup Source via MCU API

RTC Wakeup Time Setting

SysPower_RtcWakeupSet

Attribute	Description
Name	SysPower_RtcWakeupSet
Syntax	Std_ReturnType SysPower_RtcWakeupSet (uint32 WakeupTime)
Sync/Async	Synchronous
Reentrancy	No Reentrant
Parameters (in)	WakeupTime: time of rtc alarm (s)
Parameters (inout)	None
Parameters (out)	None
Return value	Std_ReturnType
Description	Set rtc wakeup time
Available via	as extern function

After setting the RTC wakeup time, timing begins only when the MCU actually initiates the sleep action; i.e., after SysPower_Suspend is called, core0 enters sleep and then timing starts.

GPIO Wakeup Source Setting

SysPower_GpioWakeupSet

Attribute	Description
Name	SysPower_GpioWakeupSet
Syntax	Std_ReturnType SysPower_GpioWakeupSet (uint32 GpioIdx, uint32 Type, uint32 Polarity)
Sync/Async	Synchronous
Reentrancy	No Reentrant
Parameters (in)	GpioIdx: index of aon gpio; Type: 0:level other:edge; Polarity: 0:low other:high
Parameters (inout)	None
Parameters (out)	None
Return value	Std_ReturnType
Description	Set gpio wakeup source
Available via	as extern function

GPIO Index Definition

AON GPIO0 ~ GPIO11

AON GPIO0 ~ GPIO20

RTC can be set as the sole wakeup source. GPIO cannot be set as the sole wakeup source. When setting GPIO as a wakeup source, RTC must also be set as a wakeup source.

Sleep Command

Sleep via button (WAKE button) (short press)
Acore enters systemctl suspend

Wakeup Command

In Deep sleep mode, automatic wakeup is possible when RTC is set as the wakeup source.
In Deep sleep mode, if GPIO is set as the wakeup source, short pressing the button (WAKE button) after sleep can wake the system.
In Light sleep mode, wakeup can only be achieved by executing a command on the MCU or calling an API interface.

Light sleep mode wakeup command

D-Robotics:/$ wakefromll
D-Robotics:/$ [0544.238961 0] main on start
...

Light sleep mode wakeup interface

Interface definition:

Pmu_PerformMainDomainOn

Attribute	Description
Name	Pmu_PerformMainDomainOn
Syntax	Std_ReturnType Pmu_PerformMainDomainOn (void)
Sync/Async	Synchronous
Reentrancy	No Reentrant
Parameters (in)	None
Parameters (inout)	None
Parameters (out)	None
Return value	Std_ReturnType
Description	main domain power on or resume, and main domain peripherals
Available via	Pmu.h

Example of waking Acore or powering on Acore:

int wakefromll(void)
{
    return Pmu_PerformMainDomainOn();
}

Interface definition:

hb_PM_RequestSt

Attribute	Description
Name	hb_PM_RequestSt
Syntax	Std_ReturnType hb_PM_RequestSt(PowerManagerState_Type ReqSt)
Sync/Async	Asynchronous
Reentrancy	No Reentrant
Parameters (in)	ReqSt: The target power status requested
Parameters (inout)	None
Parameters (out)	None
Return value	Std_ReturnType
Description	Request for power management state switching
Available via	Power_Manager_Cust.h

hb_PM_GetCurrSt

Attribute	Description
Name	hb_PM_GetCurrSt
Syntax	Std_ReturnType hb_PM_GetCurrSt(PowerManagerState_Type *CurrSt_Ptr)
Sync/Async	Synchronous
Reentrancy	No Reentrant
Parameters (in)	None
Parameters (inout)	CurrSt_Ptr: current power status
Parameters (out)	None
Return value	Std_ReturnType
Description	get current power management state
Available via	Power_Manager_Cust.h

warning

The hb_PM_RequestSt interface does not support multiple consecutive calls. A new state request can only be initiated after the current power state transition is complete. After calling hb_PM_RequestSt, you can query the current power state using the hb_PM_GetCurrSt interface to determine if the state transition is complete.

State definition:

typedef enum {
    MAINSTATE_INIT_ST = 0U,
    MAINSTATE_ON_ST,
    MAINSTATE_OFF_ST,
    MAINSTATE_SLEEP_ST,
#if (MAIN_INITIATE_PWR_SWITCH_ENABLE == STD_ON)
    SYSSTATE_SHUTDOWN_ST,
    MCUSTATE_SLEEP_ST,
    SYSSTATE_SHUTDOWN_ACTTION_IT,
    MAINSTATE_ON2SLEEP_ACTTION_IT,
    MAINSTATE_OFF_ACTTION_IT,
#endif
    MAINSTATE_FORCE_OFF_IT,
    MAINSTATE_RESET_IT,
    ......
} PowerManagerState_Type;

Example of waking Acore or powering on Acore:

int wakefromll(void)
{
    return hb_PM_RequestSt(MAINSTATE_ON_ST);
}

The sample for calling the above sleep/wakeup APIs is located in Service/Cmd_Utility/power_sample_cmd/src/PowerControl.c

Acore Sleep/Wakeup Callback

systemd is used for system service management. Related shutdown or sleep/wakeup callbacks can be used in the form supported by systemd.

Sleep: When Acore receives a sleep command (systemctl suspend), it calls systemd's suspend interface, which sends signals to all services and waits for them to exit, then calls the kernel's suspend interface to complete the sleep process.

When the system enters or exits sleep, all executable programs in the /usr/lib/systemd/system-sleep/ directory will run. The system passes two parameters to these executable programs. All scripts in the directory are processed in parallel. The system will proceed with subsequent actions only after all programs have completed execution.

Parameter Type	Value Range	Explanation
argv[1]	pre	Before sleep
	post	After wakeup
argv[2]	suspend	Suspend to ram
	hibernate	Not supported
	hybrid-sleep	Not supported
	suspend-then-hibernate	Not supported

If you need to stop a service before sleep/wakeup and start it afterward, you can add the control logic to /usr/lib/systemd/system-sleep/example.sh

#!/bin/bash

PATH=/sbin:/usr/sbin:/bin:/usr/bin

case "$1" in
pre)
        echo "==========handle before suspend==========" > /dev/kmsg
        systemctl stop hobot-example.service
        ;;
post)
        echo "==========handle after wakeup==========" > /dev/kmsg
        systemctl start hobot-example.service
        ;;
*)
        echo "Usage: $0 {pre|post}"
        exit 1
        ;;
esac

exit 0

Currently, the callback logic for D-Robotics software sleep/wakeup is implemented in the RDK code at source/hobot-configs/debian/usr/lib/systemd/system-sleep/suspend_resume.sh

warning

All upper-layer services must be stopped before sleep; otherwise, the system may not be able to perform sleep/wakeup correctly.

Chip Power Domains​

Power State List​

Sleep and Wakeup​

Setting Sleep Mode​

Display Currently Supported Sleep Modes​

Display Current Sleep Mode​

Switch Sleep Mode​

Setting Wakeup Source​

Setting Wakeup Source via MCU Command​

Setting Wakeup Source via MCU API​

RTC Wakeup Time Setting​

GPIO Wakeup Source Setting​

GPIO Index Definition​

Sleep Command​

Wakeup Command​

Light sleep mode wakeup command​

Light sleep mode wakeup interface​

Acore Sleep/Wakeup Callback​

Chip Power Domains

Power State List

Sleep and Wakeup

Setting Sleep Mode

Display Currently Supported Sleep Modes

Display Current Sleep Mode

Switch Sleep Mode

Setting Wakeup Source

Setting Wakeup Source via MCU Command

Setting Wakeup Source via MCU API

RTC Wakeup Time Setting

GPIO Wakeup Source Setting

GPIO Index Definition

Sleep Command

Wakeup Command

Light sleep mode wakeup command

Light sleep mode wakeup interface

Acore Sleep/Wakeup Callback