Intel xhci: refactor EHCI/xHCI port switching

Make the Linux xHCI driver automatically try to switchover the EHCI ports to
xHCI when an Intel xHCI host is detected, and it also finds an Intel EHCI host.

This means we will no longer have to add Intel xHCI hosts to a quirks list when
the PCI device IDs change.  Simply continuing to add new Intel xHCI PCI device
IDs to the quirks list is not sustainable.

During suspend ports may be swicthed back to EHCI by BIOS and not properly
restored to xHCI at resume. Previously both EHCI and xHCI resume functions
switched ports back to XHCI, but it's enough to do it in xHCI only
because the hub driver doesn't start running again until after both hosts are resumed.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

1 files changed, 18 insertions, 30 deletions

diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index b9848e4d3d44..2c76ef1320ea 100644
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -735,32 +735,6 @@ static int handshake(void __iomem *ptr, u32 mask, u32 done,
 	return -ETIMEDOUT;
 }
 
-#define PCI_DEVICE_ID_INTEL_LYNX_POINT_XHCI	0x8C31
-#define PCI_DEVICE_ID_INTEL_LYNX_POINT_LP_XHCI	0x9C31
-
-bool usb_is_intel_ppt_switchable_xhci(struct pci_dev *pdev)
-{
-	return pdev->class == PCI_CLASS_SERIAL_USB_XHCI &&
-		pdev->vendor == PCI_VENDOR_ID_INTEL &&
-		pdev->device == PCI_DEVICE_ID_INTEL_PANTHERPOINT_XHCI;
-}
-
-/* The Intel Lynx Point chipset also has switchable ports. */
-bool usb_is_intel_lpt_switchable_xhci(struct pci_dev *pdev)
-{
-	return pdev->class == PCI_CLASS_SERIAL_USB_XHCI &&
-		pdev->vendor == PCI_VENDOR_ID_INTEL &&
-		(pdev->device == PCI_DEVICE_ID_INTEL_LYNX_POINT_XHCI ||
-		 pdev->device == PCI_DEVICE_ID_INTEL_LYNX_POINT_LP_XHCI);
-}
-
-bool usb_is_intel_switchable_xhci(struct pci_dev *pdev)
-{
-	return usb_is_intel_ppt_switchable_xhci(pdev) ||
-		usb_is_intel_lpt_switchable_xhci(pdev);
-}
-EXPORT_SYMBOL_GPL(usb_is_intel_switchable_xhci);
-
 /*
  * Intel's Panther Point chipset has two host controllers (EHCI and xHCI) that
  * share some number of ports.  These ports can be switched between either
@@ -779,9 +753,23 @@ EXPORT_SYMBOL_GPL(usb_is_intel_switchable_xhci);
  * terminations before switching the USB 2.0 wires over, so that USB 3.0
  * devices connect at SuperSpeed, rather than at USB 2.0 speeds.
  */
-void usb_enable_xhci_ports(struct pci_dev *xhci_pdev)
+void usb_enable_intel_xhci_ports(struct pci_dev *xhci_pdev)
 {
 	u32		ports_available;
+	bool		ehci_found = false;
+	struct pci_dev	*companion = NULL;
+
+	/* make sure an intel EHCI controller exists */
+	for_each_pci_dev(companion) {
+		if (companion->class == PCI_CLASS_SERIAL_USB_EHCI &&
+		    companion->vendor == PCI_VENDOR_ID_INTEL) {
+			ehci_found = true;
+			break;
+		}
+	}
+
+	if (!ehci_found)
+		return;
 
 	/* Don't switchover the ports if the user hasn't compiled the xHCI
 	 * driver.  Otherwise they will see "dead" USB ports that don't power
@@ -840,7 +828,7 @@ void usb_enable_xhci_ports(struct pci_dev *xhci_pdev)
 	dev_dbg(&xhci_pdev->dev, "USB 2.0 ports that are now switched over "
 			"to xHCI: 0x%x\n", ports_available);
 }
-EXPORT_SYMBOL_GPL(usb_enable_xhci_ports);
+EXPORT_SYMBOL_GPL(usb_enable_intel_xhci_ports);
 
 void usb_disable_xhci_ports(struct pci_dev *xhci_pdev)
 {
@@ -921,8 +909,8 @@ static void quirk_usb_handoff_xhci(struct pci_dev *pdev)
 	writel(val, base + ext_cap_offset + XHCI_LEGACY_CONTROL_OFFSET);
 
 hc_init:
-	if (usb_is_intel_switchable_xhci(pdev))
-		usb_enable_xhci_ports(pdev);
+	if (pdev->vendor == PCI_VENDOR_ID_INTEL)
+		usb_enable_intel_xhci_ports(pdev);
 
 	op_reg_base = base + XHCI_HC_LENGTH(readl(base));