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>
This commit is contained in:
Sudeep Holla 2015-10-21 11:09:58 +01:00 committed by Rob Herring
parent 0b13ea8e26
commit a68eee4c74

View File

@ -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>;
};
[....]
};