The mechanism of SC7 for hardware with the command on Jetson AGX Xavier

[A_Y]

I would like to know the mechanism of Deep Sleep(SC7) for hardware when we use the command below on the AGX Xavier:
$ sudo systemctl suspend
How can the command control the hardware for entering SC7?

thanks

[JerryChang]

hello H_Y,

please refer to Jetson AGX Xavier Series OEM Product Design Guide, you may check [Chapter-5. Power] for the details.
thanks

[A_Y]

It says:

This can be entered under software control, and exited using various mechanisms, including wake capable pins that are listed in Table 5-8.

This means that the way of entering for Deep sleep(SC7) is only under software control, right?
However, STANDBY_REQ_N pin is that “Requests module enter standby(SC7 state)” in the Product design Guide.

[JerryChang]

hello H_Y,

are you asking hardware keyevents for putting device to deep sleep(SC7) mode?

[A_Y]

Hello Jerry,

“are you asking hardware keyevents for putting device to deep sleep(SC7) mode?”
->Yes

We plan to make custom carrier board/Jetson AGX Xavier.
If we would like to enter for Deep sleep(SC7), we just only need to use the command below:
$ sudo systemctl suspend
Is this understanding right?

[JerryChang]

hello H_Y,

that’s correct, it only support software command into deep sleep(SC7) mode.

[A_Y]

hello Jerry,

Thank you for the answer.
However, I checked the datasheet, Product Design Guide and Jetson_AGX_Xavier_Series_Pin_Descriptions sheet.
I thought that STANDBY_REQ_N pin and POWER_BTN_N one can control for entering for Deep sleep(SC7)
I would like to confirm that we cannot control for putting device to deep sleep(SC7) mode with the hardware keyevents like STANDBY_REQ_N pin and POWER_BTN_N one.
Is this true?

thanks

[JerryChang]

hello H_Y,

that’s correct, it’s an optional signal for putting device enter SC7.
you’ll also need to monitor STANDBY_ACK_N, the level should be changed when enter or exit deep sleep.

please also have device tree update, you may modify gpio-keys with… linux,code = <KEY_SUSPEND> .
this should put device enter deep sleep after you press the hardware key.
please have a try, thanks

[A_Y]

hello Jerry,

Thank you for the answer. I appreciate it.
I also would like you to tell us which file we should modify.
Could you please share the information of the file we should modify for entering for Deep sleep(SC7)?

thanks

[JerryChang]

hello H_Y,

please refer to AGX Xavier device tree,
for example, $public_sources/kernel_src/hardware/nvidia/platform/t19x/galen/kernel-dts/common/tegra194-p2822-0000-a00.dtsi
here show an example of default gpio-keys for the power button.

        gpio-keys {
                compatible = "gpio-keys";
                gpio-keys,name = "gpio-keys";

                power_key {
                        label = "power-key";
                        gpios = <&tegra_aon_gpio TEGRA194_AON_GPIO(EE, 4) GPIO_ACTIVE_LOW>;
                        linux,code = <KEY_POWER>;
                        gpio-key,wakeup;
                };