USB: EHCI: Support controllers with big endian capability regs

The two first HC capability registers (CAPLENGTH and HCIVERSION)
are defined as one 8-bit and one 16-bit register. Most HC
implementations have selected to treat these registers as part
of a 32-bit register, giving the same layout for both big and
small endian systems.

This patch adds a new quirk, big_endian_capbase, to support
controllers with big endian register interfaces that treat
HCIVERSION and CAPLENGTH as individual registers.

Signed-off-by: Jan Andersson <jan@gaisler.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/host/ehci-ath79.c b/drivers/usb/host/ehci-ath79.c
index 7ea23b5..98cc8a1 100644
--- a/drivers/usb/host/ehci-ath79.c
+++ b/drivers/usb/host/ehci-ath79.c
@@ -44,6 +44,7 @@
 	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
 	struct platform_device *pdev = to_platform_device(hcd->self.controller);
 	const struct platform_device_id *id;
+	int hclength;
 	int ret;
 
 	id = platform_get_device_id(pdev);
@@ -52,21 +53,20 @@
 		return -EINVAL;
 	}
 
+	hclength = HC_LENGTH(ehci, ehci_readl(ehci, &ehci->caps->hc_capbase));
 	switch (id->driver_data) {
 	case EHCI_ATH79_IP_V1:
 		ehci->has_synopsys_hc_bug = 1;
 
 		ehci->caps = hcd->regs;
-		ehci->regs = hcd->regs +
-			HC_LENGTH(ehci_readl(ehci, &ehci->caps->hc_capbase));
+		ehci->regs = hcd->regs + hclength;
 		break;
 
 	case EHCI_ATH79_IP_V2:
 		hcd->has_tt = 1;
 
 		ehci->caps = hcd->regs + 0x100;
-		ehci->regs = hcd->regs + 0x100 +
-			HC_LENGTH(ehci_readl(ehci, &ehci->caps->hc_capbase));
+		ehci->regs = hcd->regs + 0x100 + hclength;
 		break;
 
 	default: