USB_XHCI_EC_REG
brcm_usb_writel(0xa20c, USB_XHCI_EC_REG(xhci_ec_base, IRAADR));
val = brcm_usb_readl(USB_XHCI_EC_REG(xhci_ec_base, IRADAT));
brcm_usb_writel(val, USB_XHCI_EC_REG(xhci_ec_base, IRADAT));