ARM: tegra: add USB ULPI PHY reset GPIO to device tree

ULPI PHYs have a reset signal, and different boards use a different GPIO
for this task. Add a property to device tree to represent this.

I'm not sure if adding this property to the EHCI controller node is
entirely correct; perhaps eventually we should have explicit separate
nodes for the various PHYs. However, we don't have that right now, so this
binding seems like a reasonable choice.

Cc: <devicetree-discuss@lists.ozlabs.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <linux-usb@vger.kernel.org>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/usb/tegra-usb.txt b/Documentation/devicetree/bindings/usb/tegra-usb.txt
index 007005ddbe12..e9b005dc7625 100644
--- a/Documentation/devicetree/bindings/usb/tegra-usb.txt
+++ b/Documentation/devicetree/bindings/usb/tegra-usb.txt
@@ -12,6 +12,9 @@ Required properties :
  - nvidia,vbus-gpio : If present, specifies a gpio that needs to be
    activated for the bus to be powered.
 
+Required properties for phy_type == ulpi:
+  - nvidia,phy-reset-gpio : The GPIO used to reset the PHY.
+
 Optional properties:
   - dr_mode : dual role mode. Indicates the working mode for
    nvidia,tegra20-ehci compatible controllers.  Can be "host", "peripheral",