[PATCH v4 6/7] usb: pci-quirks: add Intel USB drcfg mux device

[Lu Baolu]

In some Intel platforms, a single usb port is shared between USB host
and device controllers. The shared port is under control of a switch
which is defined in the Intel vendor defined extended capability for
xHCI.

This patch adds the support to detect and create the platform device
for the port mux switch.

Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Reviewed-by: Felipe Balbi <balbi@xxxxxxxxxx>
---
 drivers/usb/host/pci-quirks.c    | 47 ++++++++++++++++++++++++++++++++++++++--
 drivers/usb/host/xhci-ext-caps.h |  2 ++
 2 files changed, 47 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index 26cb8c8..d2770c8 100644
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -16,10 +16,11 @@
 #include <linux/export.h>
 #include <linux/acpi.h>
 #include <linux/dmi.h>
+#include <linux/platform_device.h>
+
 #include "pci-quirks.h"
 #include "xhci-ext-caps.h"
 
-
 #define UHCI_USBLEGSUP		0xc0		/* legacy support */
 #define UHCI_USBCMD		0		/* command register */
 #define UHCI_USBINTR		4		/* interrupt register */
@@ -78,6 +79,9 @@
 #define USB_INTEL_USB3_PSSEN   0xD8
 #define USB_INTEL_USB3PRM      0xDC
 
+#define DEVICE_ID_INTEL_CHERRYVIEW_XHCI		0x22b5
+#define DEVICE_ID_INTEL_BROXTON_M_XHCI		0x0aa8
+
 /*
  * amd_chipset_gen values represent AMD different chipset generations
  */
@@ -956,6 +960,41 @@ void usb_disable_xhci_ports(struct pci_dev *xhci_pdev)
 }
 EXPORT_SYMBOL_GPL(usb_disable_xhci_ports);
 
+static void create_intel_usb_mux_device(struct pci_dev *xhci_pdev,
+					void __iomem *base)
+{
+	struct platform_device *plat_dev;
+	struct property_set pset;
+	int ret;
+
+	struct property_entry pentry[] = {
+		PROPERTY_ENTRY_U64("reg-start",
+				   pci_resource_start(xhci_pdev, 0) + 0x80d8),
+		PROPERTY_ENTRY_U64("reg-size", 8),
+		{ },
+	};
+
+	if (!xhci_find_next_ext_cap(base, 0, XHCI_EXT_CAPS_INTEL_USB_MUX))
+		return;
+
+	plat_dev = platform_device_alloc("intel-mux-drcfg",
+					 PLATFORM_DEVID_AUTO);
+	if (!plat_dev)
+		return;
+
+	plat_dev->dev.parent = &xhci_pdev->dev;
+	pset.properties = pentry;
+	platform_device_add_properties(plat_dev, &pset);
+
+	ret = platform_device_add(plat_dev);
+	if (ret) {
+		dev_warn(&xhci_pdev->dev,
+			 "failed to create mux device with error %d",
+				ret);
+		platform_device_put(plat_dev);
+	}
+}
+
 /**
  * PCI Quirks for xHCI.
  *
@@ -1022,8 +1061,12 @@ static void quirk_usb_handoff_xhci(struct pci_dev *pdev)
 	writel(val, base + ext_cap_offset + XHCI_LEGACY_CONTROL_OFFSET);
 
 hc_init:
-	if (pdev->vendor == PCI_VENDOR_ID_INTEL)
+	if (pdev->vendor == PCI_VENDOR_ID_INTEL) {
 		usb_enable_intel_xhci_ports(pdev);
+		if (pdev->device == DEVICE_ID_INTEL_CHERRYVIEW_XHCI ||
+		    pdev->device == DEVICE_ID_INTEL_BROXTON_M_XHCI)
+			create_intel_usb_mux_device(pdev, base);
+	}
 
 	op_reg_base = base + XHCI_HC_LENGTH(readl(base));
 
diff --git a/drivers/usb/host/xhci-ext-caps.h b/drivers/usb/host/xhci-ext-caps.h
index e0244fb..e368ccb 100644
--- a/drivers/usb/host/xhci-ext-caps.h
+++ b/drivers/usb/host/xhci-ext-caps.h
@@ -51,6 +51,8 @@
 #define XHCI_EXT_CAPS_ROUTE	5
 /* IDs 6-9 reserved */
 #define XHCI_EXT_CAPS_DEBUG	10
+/* Vendor defined 192-255 */
+#define XHCI_EXT_CAPS_INTEL_USB_MUX	192
 /* USB Legacy Support Capability - section 7.1.1 */
 #define XHCI_HC_BIOS_OWNED	(1 << 16)
 #define XHCI_HC_OS_OWNED	(1 << 24)
-- 
2.1.4