1Specifying wakeup capability for devices
2============================================
3
4Any device nodes
5----------------
6Nodes that describe devices which have wakeup capability may contain a
7"wakeup-source" boolean property.
8
9If the device is marked as a wakeup-source, interrupt wake capability depends
10on the device specific "interrupt-names" property. If no interrupts are labeled
11as wake capable, then it is up to the device to determine which interrupts can
12wake the system.
13
14However if a device has a dedicated interrupt as the wakeup source, then it
15needs to specify/identify it using a device specific interrupt name. In such
16cases only that interrupt can be used as a wakeup interrupt.
17
18While various legacy interrupt names exist, new devices should use "wakeup" as
19the canonical interrupt name.
20
21List of legacy properties and respective binding document
22---------------------------------------------------------
23
241. "gpio-key,wakeup"		Documentation/devicetree/bindings/input/gpio-keys{,-polled}.txt
252. "has-tpo"			Documentation/devicetree/bindings/rtc/rtc-opal.txt
263. "linux,wakeup"		Documentation/devicetree/bindings/input/gpio-matrix-keypad.txt
27				Documentation/devicetree/bindings/mfd/tc3589x.txt
28				Documentation/devicetree/bindings/input/touchscreen/ads7846.txt
294. "linux,keypad-wakeup"	Documentation/devicetree/bindings/input/qcom,pm8xxx-keypad.txt
305. "linux,input-wakeup"		Documentation/devicetree/bindings/input/samsung-keypad.txt
316. "nvidia,wakeup-source"	Documentation/devicetree/bindings/input/nvidia,tegra20-kbc.txt
32
33Examples
34--------
35
361. With "wakeup" interrupt name
37
38	device@10000 {
39		compatible	= "vendor,device-id";
40		reg		= <0x10000 0x1000>;
41		interrupts	= <0 19 4>, <0 21 4>, <0 22 4>;
42		interrupt-names	= "ack", "err", "wakeup";
43		wakeup-source;
44	};
45
462. Without "wakeup" interrupt name
47
48	embedded-controller {
49		compatible = "google,cros-ec-i2c";
50		reg = <0x1e>;
51		interrupts = <6 0>;
52		interrupt-parent = <&gpx1>;
53		pinctrl-names = "default";
54		pinctrl-0 = <&ec_irq>;
55		wakeup-source;
56	};
57
583. Without interrupts
59
60	gpio_keys {
61		compatible = "gpio-keys";
62		#address-cells = <1>;
63		#size-cells = <0>;
64
65		button@1 {
66			debounce-interval = <50>;
67			wakeup-source;
68			linux,code = <116>;
69			label = "POWER";
70			gpios = <&iofpga_gpio0 0 0x4>;
71		};
72		[....]
73	};
74