Documentation: devicetree: standardize/consolidate on "wakeup-source" property

Currently different drivers use multiple forms of annotating devices
that should be set up as wakeup sources for the system.

This patch adds a separate binding document inorder to standardize and
consolidate to use "wakeup-source" boolean property to mark the devices
as wakeup capable.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>

diff --git a/Documentation/devicetree/bindings/power/wakeup-source.txt b/Documentation/devicetree/bindings/power/wakeup-source.txt
new file mode 100644 (file)
index 0000000..963c6df
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/wakeup-source.txt
@@ -0,0 +1,71 @@
+Specifying wakeup capability for devices
+============================================
+
+Any device nodes
+----------------
+Nodes that describe devices which has wakeup capability must contain an
+"wakeup-source" boolean property.
+
+Also, if device is marked as a wakeup source, then all the primary
+interrupt(s) can be used as wakeup interrupt(s).
+
+However if the devices have dedicated interrupt as the wakeup source
+then they need to specify/identify the same using device specific
+interrupt name. In such cases only that interrupt can be used as wakeup
+interrupt.
+
+List of legacy properties and respective binding document
+---------------------------------------------------------
+
+1. "enable-sdio-wakeup"                Documentation/devicetree/bindings/mmc/mmc.txt
+2. "gpio-key,wakeup"           Documentation/devicetree/bindings/input/gpio-keys{,-polled}.txt
+3. "has-tpo"                   Documentation/devicetree/bindings/rtc/rtc-opal.txt
+4. "isil,irq2-can-wakeup-machine" Documentation/devicetree/bindings/rtc/isil,isl12057.txt
+5. "linux,wakeup"              Documentation/devicetree/bindings/input/gpio-matrix-keypad.txt
+                               Documentation/devicetree/bindings/mfd/tc3589x.txt
+                               Documentation/devicetree/bindings/input/ads7846.txt
+6. "linux,keypad-wakeup"       Documentation/devicetree/bindings/input/qcom,pm8xxx-keypad.txt
+7. "linux,input-wakeup"                Documentation/devicetree/bindings/input/samsung-keypad.txt
+8. "nvidia,wakeup-source"      Documentation/devicetree/bindings/input/nvidia,tegra20-kbc.txt
+
+Examples
+--------
+
+1. With "wakeup" interrupt name
+
+       device@10000 {
+               compatible      = "vendor,device-id";
+               reg             = <0x10000 0x1000>;
+               interrupts      = <0 19 4>, <0 21 4>, <0 22 4>;
+               interrupt-names = "ack", "err", "wakeup";
+               wakeup-source;
+       };
+
+2. Without "wakeup" interrupt name
+
+       embedded-controller {
+               compatible = "google,cros-ec-i2c";
+               reg = <0x1e>;
+               interrupts = <6 0>;
+               interrupt-parent = <&gpx1>;
+               pinctrl-names = "default";
+               pinctrl-0 = <&ec_irq>;
+               wakeup-source;
+       };
+
+3. Without interrupts
+
+       gpio_keys {
+               compatible = "gpio-keys";
+               #address-cells = <1>;
+               #size-cells = <0>;
+
+               button@1 {
+                       debounce_interval = <50>;
+                       wakeup-source;
+                       linux,code = <116>;
+                       label = "POWER";
+                       gpios = <&iofpga_gpio0 0 0x4>;
+               };
+               [....]
+       };