[PATCH v2 2/2] PCI: Override Synopsys USB 3.x HAPS device class

[Thinh Nguyen <thinh.nguyen@synopsys.com>]

Synopsys USB 3.x host HAPS platform has a class code of
PCI_CLASS_SERIAL_USB_XHCI, and xhci driver can claim it. However, these
devices should use dwc3-haps driver. Change these devices' class code to
PCI_CLASS_SERIAL_USB_DEVICE to prevent the xhci-pci driver from claiming
them.

Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
---
Change in v2:
- Revise title to fit PCI patches' convention
- Override pci class instead of driver

 drivers/pci/quirks.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 4700d24e5d55..c84f81c42a1f 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -618,6 +618,32 @@ static void quirk_amd_nl_class(struct pci_dev *pdev)
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_NL_USB,
 		quirk_amd_nl_class);
 
+/*
+ * Synopsys USB 3.x host HAPS platform has a class code of
+ * PCI_CLASS_SERIAL_USB_XHCI, and xhci driver can claim it. However, these
+ * devices should use dwc3-haps driver. Change these devices' class code to
+ * PCI_CLASS_SERIAL_USB_DEVICE to prevent the xhci-pci driver from claiming
+ * them.
+ */
+static void quirk_synopsys_haps(struct pci_dev *pdev)
+{
+	u32 class = pdev->class;
+
+	switch (pdev->device) {
+	case PCI_DEVICE_ID_SYNOPSYS_HAPSUSB3:
+	case PCI_DEVICE_ID_SYNOPSYS_HAPSUSB3_AXI:
+	case PCI_DEVICE_ID_SYNOPSYS_HAPSUSB31:
+		pdev->class = PCI_CLASS_SERIAL_USB_DEVICE;
+		pci_info(pdev, "PCI class overridden (%#08x -> %#08x) so dwc3 driver can claim this instead of xhci\n",
+			 class, pdev->class);
+		break;
+	default:
+		return;
+	}
+}
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SYNOPSYS, PCI_ANY_ID,
+			 quirk_synopsys_haps);
+
 /*
  * Let's make the southbridge information explicit instead of having to
  * worry about people probing the ACPI areas, for example.. (Yes, it
-- 
2.11.0