"usb_otg_ss_refclk960m" is needed by usb2 phy present in omap5. For
omap4, the clk_get of this clock will fail since it does not have this
clock.

Signed-off-by: Kishon Vijay Abraham I <redacted>
---
 Documentation/devicetree/bindings/usb/usb-phy.txt |    3 +++
 drivers/usb/phy/omap-usb2.c                       |   28 ++++++++++++++++++++-
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/usb/usb-phy.txt b/Documentation/devicetree/bindings/usb/usb-phy.txt
index 7c5fd89..d5626de 100644
--- a/Documentation/devicetree/bindings/usb/usb-phy.txt
+++ b/Documentation/devicetree/bindings/usb/usb-phy.txt

@@ -24,6 +24,9 @@ Required properties:
 add the address of control module phy power register until a driver for
 control module is added
 
+Optional properties:
+ - has960mhzclk: should be added if the phy needs 960mhz clock
+
 This is usually a subnode of ocp2scp to which it is connected.
 
 usb3phy@4a084400 {

diff --git a/drivers/usb/phy/omap-usb2.c b/drivers/usb/phy/omap-usb2.c
index d36c282..d6612ba 100644
--- a/drivers/usb/phy/omap-usb2.c
+++ b/drivers/usb/phy/omap-usb2.c

@@ -146,6 +146,7 @@ static int __devinit omap_usb2_probe(struct platform_device *pdev)
 	struct omap_usb			*phy;
 	struct usb_otg			*otg;
 	struct resource			*res;
+	struct device_node		*np = pdev->dev.of_node;
 
 	phy = devm_kzalloc(&pdev->dev, sizeof(*phy), GFP_KERNEL);
 	if (!phy) {

@@ -190,6 +191,15 @@ static int __devinit omap_usb2_probe(struct platform_device *pdev)
 	}
 	clk_prepare(phy->wkupclk);
 
+	if (of_property_read_bool(np, "has960mhzclk")) {
+		phy->optclk = devm_clk_get(phy->dev, "usb_otg_ss_refclk960m");
+		if (IS_ERR(phy->optclk)) {
+			dev_err(&pdev->dev, "unable to get refclk960m\n");
+			return PTR_ERR(phy->optclk);
+		}
+		clk_prepare(phy->optclk);
+	}