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IMX suspend

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Suspend to RAM


1 Suspend to RAM

This state offers significant power savings as everything in the system is put into a low-power state, except for memory, which is placed into the self-refresh mode to retain its contents.

To suspend to RAM:

# echo mem > /sys/power/state

2 Wake up

There are many possible ways to wake up from suspend.
A few examples:
- Pushing the ON/OFF button (when present on the board)
- Pushing a button on the board which has the boolean property "gpio-key,wakeup" set in its device tree node (under gpio_keys), e.g.:

	gpio-keys {
		compatible = "gpio-keys";
		pinctrl-names = "default";
		pinctrl-0 = <&pinctrl_gpio_keys>;

		back {
			label = "Back";
			gpios = <&gpio5 20 GPIO_ACTIVE_LOW>;
			linux,code = <KEY_BACK>;
			gpio-key,wakeup;
		};
	};

- Using the RTC you can wake at a specific time (see the RTC section)


3 Current consumption when suspended

3.1 VAR-SOM-MX6 "L" revisions (1GB RAM)

17.2mA with a 3.7V Li-Po

Warning: Only "L" (for Low-power) revisions of VAR-SOM-MX6 can be operated at 3.7V!

3.2 DART-MX6

9mA with a 3.7V Li-Po

3.3 VAR-DART-6UL

4.5mA at 3.3V

3.4 VAR-SOM-MX7

TBD