Latest revision as of 19:02, 11 April 2024

Warning: This page is designed to be used with a 'release' URL parameter.

This page is using the default release am62-yocto-kirkstone-6.1.46_09.01.00.08-v1.0.
To view this page for a specific Variscite SoM and software release, please follow these steps:

Visit variwiki.com
Select your SoM
Select the software release

VAR-SOM-AM62 Low Power Modes

Background

TI's AM62 contains numerous low power modes and features. Extensive documentation on the subject can be found by consulting TI's Low Power Modes article.

While this wiki article does not serve to duplicate information, it will highlight some of the key important modes and usages on Variscite's development platform.

Suspend to RAM (Deep Sleep)

Deep Sleep AKA Suspend-to-RAM is a low-power mode that allows an embedded device to retain its state in RAM while the processor is turned off. This can save a significant amount of power, especially in devices that are battery-powered.

In order to enter deep sleep, use the following command:

root@am62x-var-som:~# pm-suspend
[   26.430955] mmc2: card 0001 removed
[   26.668685] am65-cpsw-nuss 8000000.ethernet eth0: Link is Down
[   26.716750] am65-cpsw-nuss 8000000.ethernet eth1: Link is Down
[   26.875564] PM: suspend entry (deep)
[   26.880123] Filesystems sync: 0.000 seconds
[   26.904501] remoteproc remoteproc0: stopped remote processor 5000000.m4fss
[   26.925158] Freezing user space processes
[   26.931899] Freezing user space processes completed (elapsed 0.002 seconds)
[   26.938937] OOM killer disabled.
[   26.942261] Freezing remaining freezable tasks
[   26.948416] Freezing remaining freezable tasks completed (elapsed 0.001 seconds)
[   26.955832] printk: Suspending console(s) (use no_console_suspend to debug)

Wake up

Various wakeup sources are possible on the AM62. On Variscite's development platform, the touchscreen has been configured as a wakeup source using TI's "I/O Daisy Chain" method.

ft5x06_ts: ft5x06_ts@38 {
	compatible = "edt,edt-ft5206";
	reg = <0x38>;
	pinctrl-names = "default";
	pinctrl-0 = <&captouch_pins_default>;
	interrupts-extended = <&main_gpio1 16 IRQ_TYPE_EDGE_FALLING>,
                              <&main_pmx0 0x1B8>;
	interrupt-names = "irq", "wakeup";
	touchscreen-size-x = <800>;
	touchscreen-size-y = <480>;
	touchscreen-inverted-x;
	touchscreen-inverted-y;
	wakeup-source;
	status = "okay";
};

Touching the screen after the system has been suspended will wake the system.

For more information on available wake-up sources, please consult TI's Wakeup Sources article.

CPU Hotplug

See the Variscite Set the CPU freq. and number of active cores article for more information.

AM62 Low Power: Difference between revisions

Latest revision as of 19:02, 11 April 2024

Contents

Background

Suspend to RAM (Deep Sleep)

Wake up

CPU Hotplug

@@ Line 3: / Line 3: @@
 --> {{#lst:Yocto_Platform_Customization|{{#var:RELEASE_PARAM}}}} <!--
 --> {{#lst:B2QT_Platform_Customization|{{#var:RELEASE_PARAM}}}} <!--
+--> {{#switch: {{#var:RELEASE_NAME}}
+| am62-yocto-kirkstone-6.1.46_09.01.00.08-v1.0=
+ {{#vardefine:TI_LOW_POWER_DOCS_LINK|https://software-dl.ti.com/processor-sdk-linux/esd/AM62X/09_01_00_08/exports/docs/linux/Foundational_Components/Kernel/Kernel_Drivers/Power_Management/pm_low_power_modes.html}}
+ {{#vardefine:TI_WAKEUP_SOURCES_DOCS_LINK|https://software-dl.ti.com/processor-sdk-linux/esd/AM62X/09_01_00_08/exports/docs/linux/Foundational_Components/Kernel/Kernel_Drivers/Power_Management/pm_wakeup_sources.html#wakeup-sources}}
+| #default=}
+}} <!--
 --> {{PageHeader|{{#var:HARDWARE_NAME}} Low Power Modes}} {{DocImage|category1=Yocto|category2={{#var:HARDWARE_NAME}}}} __toc__
 = Background =
-TI's AM62 contains numerous low power modes. Extensive documentation on the subject can be found by visiting:
+TI's AM62 contains numerous low power modes and features. Extensive documentation on the subject can be found by consulting TI's [{{#var:TI_LOW_POWER_DOCS_LINK}} Low Power Modes] article.
-https://software-dl.ti.com/processor-sdk-linux/esd/AM62X/09_01_00_08/exports/docs/linux/Foundational_Components/Kernel/Kernel_Drivers/Power_Management/pm_low_power_modes.html
+<br>
+<br>
+While this wiki article does not serve to duplicate information, it will highlight some of the key important modes and usages on Variscite's development platform.
-While this guide does not serve to duplicate information, it will highlight some of the key important modes and usages on Variscite's development platform.
+= Suspend to RAM (Deep Sleep) =
+Deep Sleep AKA Suspend-to-RAM is a low-power mode that allows an embedded device to retain its state in RAM while the processor is turned off. This can save a significant amount of power, especially in devices that are battery-powered.
-= Suspend to RAM (Deep Sleep) =
+In order to enter deep sleep, use the following command:
+ root@am62x-var-som:~# pm-suspend
+ [   26.430955] mmc2: card 0001 removed
+ [   26.668685] am65-cpsw-nuss 8000000.ethernet eth0: Link is Down
+ [   26.716750] am65-cpsw-nuss 8000000.ethernet eth1: Link is Down
+ [   26.875564] PM: suspend entry (deep)
+ [   26.880123] Filesystems sync: 0.000 seconds
+ [   26.904501] remoteproc remoteproc0: stopped remote processor 5000000.m4fss
+ [   26.925158] Freezing user space processes
+ [   26.931899] Freezing user space processes completed (elapsed 0.002 seconds)
+ [   26.938937] OOM killer disabled.
+ [   26.942261] Freezing remaining freezable tasks
+ [   26.948416] Freezing remaining freezable tasks completed (elapsed 0.001 seconds)
+ [   26.955832] printk: Suspending console(s) (use no_console_suspend to debug)
 = Wake up =
+Various wakeup sources are possible on the AM62. On Variscite's development platform, the touchscreen has been configured as a wakeup source using TI's "I/O Daisy Chain" method.
+ ft5x06_ts: ft5x06_ts@38 {
+ 	compatible = "edt,edt-ft5206";
+ 	reg = <0x38>;
+ 	pinctrl-names = "default";
+ 	pinctrl-0 = <&captouch_pins_default>;
+ 	interrupts-extended = <&main_gpio1 16 IRQ_TYPE_EDGE_FALLING>,
+                               <&main_pmx0 0x1B8>;
+ 	interrupt-names = "irq", "wakeup";
+ 	touchscreen-size-x = <800>;
+ 	touchscreen-size-y = <480>;
+ 	touchscreen-inverted-x;
+ 	touchscreen-inverted-y;
+ 	wakeup-source;
+ 	status = "okay";
+ };
+Touching the screen after the system has been suspended will wake the system.
-TODO
+For more information on available wake-up sources, please consult TI's [{{#var:TI_WAKEUP_SOURCES_DOCS_LINK}} Wakeup Sources] article.
 = CPU Hotplug =
+See the Variscite [https://variwiki.com/index.php?title=CPU_freq_and_num_of_cores Set the CPU freq. and number of active cores] article for more information.
-TODO