xhci-ext-caps.c: Add property to disable Intel SW switch

In platforms like Cherrytrail, 'SW switch enable' bit
should not be enabled for role switch. This patch
adds a property to Intel USB Role Switch platform driver
to denote that SW switch should be disabled in
Cherrytrail devices.

Signed-off-by: Saranya Gopal <[e-mail]>
Signed-off-by: Balaji Manoharan <[e-mail]>
Suggested-by: Heikki Krogerus <[e-mail]>
Reviewed-by: Heikki Krogerus <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/host/xhci-ext-caps.c

···
  */
 
 #include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/pci.h>
 #include "xhci.h"
 
 #define USB_SW_DRV_NAME		"intel_xhci_usb_sw"
 #define USB_SW_RESOURCE_SIZE	0x400
+
+#define PCI_DEVICE_ID_INTEL_CHERRYVIEW_XHCI	0x22b5
+
+static const struct property_entry role_switch_props[] = {
+	PROPERTY_ENTRY_BOOL("sw_switch_disable"),
+	{},
+};
 
 static void xhci_intel_unregister_pdev(void *arg)
 {
···
 	struct usb_hcd *hcd = xhci_to_hcd(xhci);
 	struct device *dev = hcd->self.controller;
 	struct platform_device *pdev;
+	struct pci_dev *pci = to_pci_dev(dev);
 	struct resource	res = { 0, };
 	int ret;
 
···
 		dev_err(dev, "couldn't add resources to intel_xhci_usb_sw pdev\n");
 		platform_device_put(pdev);
 		return ret;
+	}
+
+	if (pci->device == PCI_DEVICE_ID_INTEL_CHERRYVIEW_XHCI) {
+		ret = platform_device_add_properties(pdev, role_switch_props);
+		if (ret) {
+			dev_err(dev, "failed to register device properties\n");
+			return ret;
+		}
 	}
 
 	pdev->dev.parent = dev;