Revision as of 15:57, 13 December 2016

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

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)

Current consumption when suspended

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!

DART-MX6

9mA with a 3.7V Li-Po

VAR-DART-6UL

4.5mA at 3.3V

VAR-SOM-MX7

TBD

@@ Line 9: / Line 9: @@
 $ echo mem > /sys/power/state
 </pre>
-<br>
-To wake up:<br>
+= Wake up =
-There are a few ways to wake up from suspend.<br>
+There are many possible ways to wake up from suspend.<br>
-For example, using the RTC you can wake at a specific time (see the RTC section).<br>
+A few examples:<br>
-Another way is to push a button on the board which is set as wakeable.<br>
+- Pushing the ON/OFF button (when present on the board)<br>
+- 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 [[IMX_RTC|RTC section]])<br>
 = Current consumption when suspended =
@@ Line 28: / Line 45: @@
 == VAR-SOM-MX7 ==
-To be updated
+TBD

IMX suspend: Difference between revisions