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path: root/drivers/usb/host/pci-quirks.c
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Diffstat (limited to 'drivers/usb/host/pci-quirks.c')
-rw-r--r--drivers/usb/host/pci-quirks.c63
1 files changed, 63 insertions, 0 deletions
diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index f16c59d5f48..fd930618c28 100644
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -69,6 +69,9 @@
#define NB_PIF0_PWRDOWN_0 0x01100012
#define NB_PIF0_PWRDOWN_1 0x01100013
+#define USB_INTEL_XUSB2PR 0xD0
+#define USB_INTEL_USB3_PSSEN 0xD8
+
static struct amd_chipset_info {
struct pci_dev *nb_dev;
struct pci_dev *smbus_dev;
@@ -673,6 +676,64 @@ static int handshake(void __iomem *ptr, u32 mask, u32 done,
return -ETIMEDOUT;
}
+bool usb_is_intel_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;
+}
+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
+ * controller. Not all of the ports under the EHCI host controller may be
+ * switchable.
+ *
+ * The ports should be switched over to xHCI before PCI probes for any device
+ * start. This avoids active devices under EHCI being disconnected during the
+ * port switchover, which could cause loss of data on USB storage devices, or
+ * failed boot when the root file system is on a USB mass storage device and is
+ * enumerated under EHCI first.
+ *
+ * We write into the xHC's PCI configuration space in some Intel-specific
+ * registers to switch the ports over. The USB 3.0 terminations and the USB
+ * 2.0 data wires are switched separately. We want to enable the SuperSpeed
+ * 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)
+{
+ u32 ports_available;
+
+ ports_available = 0xffffffff;
+ /* Write USB3_PSSEN, the USB 3.0 Port SuperSpeed Enable
+ * Register, to turn on SuperSpeed terminations for all
+ * available ports.
+ */
+ pci_write_config_dword(xhci_pdev, USB_INTEL_USB3_PSSEN,
+ cpu_to_le32(ports_available));
+
+ pci_read_config_dword(xhci_pdev, USB_INTEL_USB3_PSSEN,
+ &ports_available);
+ dev_dbg(&xhci_pdev->dev, "USB 3.0 ports that are now enabled "
+ "under xHCI: 0x%x\n", ports_available);
+
+ ports_available = 0xffffffff;
+ /* Write XUSB2PR, the xHC USB 2.0 Port Routing Register, to
+ * switch the USB 2.0 power and data lines over to the xHCI
+ * host.
+ */
+ pci_write_config_dword(xhci_pdev, USB_INTEL_XUSB2PR,
+ cpu_to_le32(ports_available));
+
+ pci_read_config_dword(xhci_pdev, USB_INTEL_XUSB2PR,
+ &ports_available);
+ 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);
+
/**
* PCI Quirks for xHCI.
*
@@ -732,6 +793,8 @@ static void __devinit quirk_usb_handoff_xhci(struct pci_dev *pdev)
writel(XHCI_LEGACY_DISABLE_SMI,
base + ext_cap_offset + XHCI_LEGACY_CONTROL_OFFSET);
+ if (usb_is_intel_switchable_xhci(pdev))
+ usb_enable_xhci_ports(pdev);
hc_init:
op_reg_base = base + XHCI_HC_LENGTH(readl(base));