usb: host: ehci-msm: Remove dependency on OTG PHY

Currently the EHCI MSM driver has a hard dependency to be created
by an OTG layer, namely the phy-msm-usb driver. In some cases or
board configurations we want to allow the EHCI host to be
instantiated without OTG capability. Instead, relax the dependency
on having an OTG PHY being present and call usb_add_hcd() directly.
Signed-off-by: Jack Pham <jackp@codeaurora.org>
Signed-off-by: Timur Tabi <timur@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/ehci-msm.c

@@ -106,9 +106,9 @@ static int ehci_msm_probe(struct platform_device *pdev)
 	}
 
 	/*
-	 * OTG driver takes care of PHY initialization, clock management,
-	 * powering up VBUS, mapping of registers address space and power
-	 * management.
+	 * If there is an OTG driver, let it take care of PHY initialization,
+	 * clock management, 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);
@@ -116,27 +116,35 @@ static int ehci_msm_probe(struct platform_device *pdev)
 		phy = devm_usb_get_phy(&pdev->dev, USB_PHY_TYPE_USB2);
 
 	if (IS_ERR(phy)) {
+		if (PTR_ERR(phy) == -EPROBE_DEFER) {
 			dev_err(&pdev->dev, "unable to find transceiver\n");
 			ret = -EPROBE_DEFER;
 			goto put_hcd;
 		}
+		phy = NULL;
+	}
+
+	hcd->usb_phy = phy;
+	device_init_wakeup(&pdev->dev, 1);
 
+	if (phy && phy->otg) {
+		/*
+		 * MSM OTG driver takes care of adding the HCD and
+		 * placing hardware into low power mode via runtime PM.
+		 */
 		ret = otg_set_host(phy->otg, &hcd->self);
 		if (ret < 0) {
 			dev_err(&pdev->dev, "unable to register with transceiver\n");
 			goto put_hcd;
 		}
 
-	hcd->usb_phy = phy;
-	device_init_wakeup(&pdev->dev, 1);
-	/*
-	 * OTG device parent of HCD takes care of putting
-	 * hardware into low power mode.
-	 */
 		pm_runtime_no_callbacks(&pdev->dev);
 		pm_runtime_enable(&pdev->dev);
-
-	/* FIXME: need to call usb_add_hcd() here? */
+	} else {
+		ret = usb_add_hcd(hcd, hcd->irq, IRQF_SHARED);
+		if (ret)
+			goto put_hcd;
+	}
 
 	return 0;
 
@@ -154,9 +162,10 @@ static int ehci_msm_remove(struct platform_device *pdev)
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_set_suspended(&pdev->dev);
 
+	if (hcd->usb_phy && hcd->usb_phy->otg)
 		otg_set_host(hcd->usb_phy->otg, NULL);
-
-	/* FIXME: need to call usb_remove_hcd() here? */
+	else
+		usb_remove_hcd(hcd);
 
 	usb_put_hcd(hcd);