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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.c123
1 files changed, 123 insertions, 0 deletions
diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index 033c2846ce5..83b5f9cea85 100644
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -15,6 +15,7 @@
#include <linux/delay.h>
#include <linux/acpi.h>
#include "pci-quirks.h"
+#include "xhci-ext-caps.h"
#define UHCI_USBLEGSUP 0xc0 /* legacy support */
@@ -341,7 +342,127 @@ static void __devinit quirk_usb_disable_ehci(struct pci_dev *pdev)
return;
}
+/*
+ * handshake - spin reading a register until handshake completes
+ * @ptr: address of hc register to be read
+ * @mask: bits to look at in result of read
+ * @done: value of those bits when handshake succeeds
+ * @wait_usec: timeout in microseconds
+ * @delay_usec: delay in microseconds to wait between polling
+ *
+ * Polls a register every delay_usec microseconds.
+ * Returns 0 when the mask bits have the value done.
+ * Returns -ETIMEDOUT if this condition is not true after
+ * wait_usec microseconds have passed.
+ */
+static int handshake(void __iomem *ptr, u32 mask, u32 done,
+ int wait_usec, int delay_usec)
+{
+ u32 result;
+
+ do {
+ result = readl(ptr);
+ result &= mask;
+ if (result == done)
+ return 0;
+ udelay(delay_usec);
+ wait_usec -= delay_usec;
+ } while (wait_usec > 0);
+ return -ETIMEDOUT;
+}
+
+/**
+ * PCI Quirks for xHCI.
+ *
+ * Takes care of the handoff between the Pre-OS (i.e. BIOS) and the OS.
+ * It signals to the BIOS that the OS wants control of the host controller,
+ * and then waits 5 seconds for the BIOS to hand over control.
+ * If we timeout, assume the BIOS is broken and take control anyway.
+ */
+static void __devinit quirk_usb_handoff_xhci(struct pci_dev *pdev)
+{
+ void __iomem *base;
+ int ext_cap_offset;
+ void __iomem *op_reg_base;
+ u32 val;
+ int timeout;
+
+ if (!mmio_resource_enabled(pdev, 0))
+ return;
+
+ base = ioremap_nocache(pci_resource_start(pdev, 0),
+ pci_resource_len(pdev, 0));
+ if (base == NULL)
+ return;
+ /*
+ * Find the Legacy Support Capability register -
+ * this is optional for xHCI host controllers.
+ */
+ ext_cap_offset = xhci_find_next_cap_offset(base, XHCI_HCC_PARAMS_OFFSET);
+ do {
+ if (!ext_cap_offset)
+ /* We've reached the end of the extended capabilities */
+ goto hc_init;
+ val = readl(base + ext_cap_offset);
+ if (XHCI_EXT_CAPS_ID(val) == XHCI_EXT_CAPS_LEGACY)
+ break;
+ ext_cap_offset = xhci_find_next_cap_offset(base, ext_cap_offset);
+ } while (1);
+
+ /* If the BIOS owns the HC, signal that the OS wants it, and wait */
+ if (val & XHCI_HC_BIOS_OWNED) {
+ writel(val & XHCI_HC_OS_OWNED, base + ext_cap_offset);
+
+ /* Wait for 5 seconds with 10 microsecond polling interval */
+ timeout = handshake(base + ext_cap_offset, XHCI_HC_BIOS_OWNED,
+ 0, 5000, 10);
+
+ /* Assume a buggy BIOS and take HC ownership anyway */
+ if (timeout) {
+ dev_warn(&pdev->dev, "xHCI BIOS handoff failed"
+ " (BIOS bug ?) %08x\n", val);
+ writel(val & ~XHCI_HC_BIOS_OWNED, base + ext_cap_offset);
+ }
+ }
+
+ /* Disable any BIOS SMIs */
+ writel(XHCI_LEGACY_DISABLE_SMI,
+ base + ext_cap_offset + XHCI_LEGACY_CONTROL_OFFSET);
+
+hc_init:
+ op_reg_base = base + XHCI_HC_LENGTH(readl(base));
+
+ /* Wait for the host controller to be ready before writing any
+ * operational or runtime registers. Wait 5 seconds and no more.
+ */
+ timeout = handshake(op_reg_base + XHCI_STS_OFFSET, XHCI_STS_CNR, 0,
+ 5000, 10);
+ /* Assume a buggy HC and start HC initialization anyway */
+ if (timeout) {
+ val = readl(op_reg_base + XHCI_STS_OFFSET);
+ dev_warn(&pdev->dev,
+ "xHCI HW not ready after 5 sec (HC bug?) "
+ "status = 0x%x\n", val);
+ }
+
+ /* Send the halt and disable interrupts command */
+ val = readl(op_reg_base + XHCI_CMD_OFFSET);
+ val &= ~(XHCI_CMD_RUN | XHCI_IRQS);
+ writel(val, op_reg_base + XHCI_CMD_OFFSET);
+
+ /* Wait for the HC to halt - poll every 125 usec (one microframe). */
+ timeout = handshake(op_reg_base + XHCI_STS_OFFSET, XHCI_STS_HALT, 1,
+ XHCI_MAX_HALT_USEC, 125);
+ if (timeout) {
+ val = readl(op_reg_base + XHCI_STS_OFFSET);
+ dev_warn(&pdev->dev,
+ "xHCI HW did not halt within %d usec "
+ "status = 0x%x\n", XHCI_MAX_HALT_USEC, val);
+ }
+
+ iounmap(base);
+}
static void __devinit quirk_usb_early_handoff(struct pci_dev *pdev)
{
@@ -351,5 +472,7 @@ static void __devinit quirk_usb_early_handoff(struct pci_dev *pdev)
quirk_usb_handoff_ohci(pdev);
else if (pdev->class == PCI_CLASS_SERIAL_USB_EHCI)
quirk_usb_disable_ehci(pdev);
+ else if (pdev->class == PCI_CLASS_SERIAL_USB_XHCI)
+ quirk_usb_handoff_xhci(pdev);
}
DECLARE_PCI_FIXUP_FINAL(PCI_ANY_ID, PCI_ANY_ID, quirk_usb_early_handoff);