dt-bindings: pinctrl: add a 'pinctrl-use-default' property

Pin setup may be optional in some cases such as the reset default works
or the pin setup is done by the bootloader. In these cases, it is optional
for the OS to support managing the pin controller and pin setup. In order
to support this scenario, add a property 'pinctrl-use-default' to indicate
that the pin configuration is optional.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
index ad9bbbba36e9d529481f1d9b265b29dbf15d372c..cef2b5855d60fdaef2c62960e19dd0f087564cc5 100644 (file)
--- a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
+++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
@@ -103,6 +103,12 @@ Optional properties:
 #pinctrl-cells:        Number of pin control cells in addition to the index within the
                pin controller device instance
 
+pinctrl-use-default: Boolean. Indicates that the OS can use the boot default
+               pin configuration. This allows using an OS that does not have a
+               driver for the pin controller. This property can be set either
+               globally for the pin controller or in child nodes for individual
+               pin group control.
+
 Pin controller devices should contain the pin configuration nodes that client
 devices reference.