usb: host: xhci-plat: prepare operation w/o shared hcd

This patch prepares xhci-plat for the following scenario
- If either of the root hubs has no ports, then omit shared hcd
- Main hcd can be USB3 if there are no USB2 ports
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20220511220450.85367-5-mathias.nyman@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci-plat.c

@@ -180,7 +180,7 @@ static int xhci_plat_probe(struct platform_device *pdev)
 	struct device		*sysdev, *tmpdev;
 	struct xhci_hcd		*xhci;
 	struct resource         *res;
-	struct usb_hcd		*hcd;
+	struct usb_hcd		*hcd, *usb3_hcd;
 	int			ret;
 	int			irq;
 	struct xhci_plat_priv	*priv = NULL;
@@ -327,21 +327,26 @@ static int xhci_plat_probe(struct platform_device *pdev)
 	if (ret)
 		goto disable_usb_phy;
 
-	xhci->shared_hcd = __usb_create_hcd(driver, sysdev, &pdev->dev,
-			dev_name(&pdev->dev), hcd);
-	if (!xhci->shared_hcd) {
-		ret = -ENOMEM;
-		goto dealloc_usb2_hcd;
-	}
+	if (!xhci_has_one_roothub(xhci)) {
+		xhci->shared_hcd = __usb_create_hcd(driver, sysdev, &pdev->dev,
+						    dev_name(&pdev->dev), hcd);
+		if (!xhci->shared_hcd) {
+			ret = -ENOMEM;
+			goto dealloc_usb2_hcd;
+		}
 
-	xhci->shared_hcd->tpl_support = hcd->tpl_support;
+		xhci->shared_hcd->tpl_support = hcd->tpl_support;
+	}
 
-	if (HCC_MAX_PSA(xhci->hcc_params) >= 4)
-		xhci->shared_hcd->can_do_streams = 1;
+	usb3_hcd = xhci_get_usb3_hcd(xhci);
+	if (usb3_hcd && HCC_MAX_PSA(xhci->hcc_params) >= 4)
+		usb3_hcd->can_do_streams = 1;
 
-	ret = usb_add_hcd(xhci->shared_hcd, irq, IRQF_SHARED);
-	if (ret)
-		goto put_usb3_hcd;
+	if (xhci->shared_hcd) {
+		ret = usb_add_hcd(xhci->shared_hcd, irq, IRQF_SHARED);
+		if (ret)
+			goto put_usb3_hcd;
+	}
 
 	device_enable_async_suspend(&pdev->dev);
 	pm_runtime_put_noidle(&pdev->dev);