USB: ehci-msm: Add device tree support and binding information

Allows MSM EHCI controller to be specified via device tree.
Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Acked-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/usb/msm-hsusb.txt

+MSM SoC HSUSB controllers
+
+EHCI
+
+Required properties:
+- compatible:	Should contain "qcom,ehci-host"
+- regs:			offset and length of the register set in the memory map
+- usb-phy:		phandle for the PHY device
+
+Example EHCI controller device node:
+
+	ehci: ehci@f9a55000 {
+		compatible = "qcom,ehci-host";
+		reg = <0xf9a55000 0x400>;
+		usb-phy = <&usb_otg>;
+	};
+

drivers/usb/host/ehci-msm.c

@@ -108,10 +108,14 @@ static int ehci_msm_probe(struct platform_device *pdev)
 	 * powering up VBUS, mapping of registers address space and power
 	 * management.
 	 */
+	if (pdev->dev.of_node)
+		phy = devm_usb_get_phy_by_phandle(&pdev->dev, "usb-phy", 0);
+	else
 		phy = devm_usb_get_phy(&pdev->dev, USB_PHY_TYPE_USB2);
+
 	if (IS_ERR(phy)) {
 		dev_err(&pdev->dev, "unable to find transceiver\n");
-		ret = -ENODEV;
+		ret = -EPROBE_DEFER;
 		goto put_hcd;
 	}
 
@@ -187,12 +191,19 @@ static const struct dev_pm_ops ehci_msm_dev_pm_ops = {
 	.resume          = ehci_msm_pm_resume,
 };
 
+static struct of_device_id msm_ehci_dt_match[] = {
+	{ .compatible = "qcom,ehci-host", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, msm_ehci_dt_match);
+
 static struct platform_driver ehci_msm_driver = {
 	.probe	= ehci_msm_probe,
 	.remove	= ehci_msm_remove,
 	.driver = {
 		   .name = "msm_hsusb_host",
 		   .pm = &ehci_msm_dev_pm_ops,
+		   .of_match_table = msm_ehci_dt_match,
 	},
 };