NFC: trf7970a: Document the 'vin-voltage-override' DTS property

The trf7970a driver recently had support for the
'vin-voltage-override' property added to it.  This
property is used to override the value given by
the regulator subsystem for the VIN pin's voltage.

Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

diff --git a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
index 1e43613..02a381d 100644 (file)
--- a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
+++ b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
@@ -13,6 +13,7 @@ Optional SoC Specific Properties:
 - pinctrl-names: Contains only one value - "default".
 - pintctrl-0: Specifies the pin control groups used for this controller.
 - autosuspend-delay: Specify autosuspend delay in milliseconds.
+- vin-voltage-override: Specify voltage of VIN pin in microvolts.
 
 Example (for ARM-based BeagleBone with TRF7970A on SPI1):
 
@@ -30,6 +31,7 @@ Example (for ARM-based BeagleBone with TRF7970A on SPI1):
                ti,enable-gpios = <&gpio2 2 GPIO_ACTIVE_LOW>,
                                  <&gpio2 5 GPIO_ACTIVE_LOW>;
                vin-supply = <&ldo3_reg>;
+               vin-voltage-override = <5000000>;
                autosuspend-delay = <30000>;
                status = "okay";
        };