1 files changed, 32 insertions, 0 deletions

diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 74dbc6c8228f..5f28b74bb8d3 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -92,6 +92,7 @@ struct ehci_hcd {			/* one per controller */
         unsigned                is_tdi_rh_tt:1; /* TDI roothub with TT */
         unsigned                no_selective_suspend:1;
         unsigned                has_fsl_port_bug:1; /* FreeScale */
+        unsigned                big_endian_mmio:1;
 
         u8                      sbrn;           /* packed release number */
 
@@ -651,6 +652,37 @@ ehci_port_speed(struct ehci_hcd *ehci, unsigned int portsc)
 #define ehci_has_fsl_portno_bug(e)              (0)
 #endif
 
+/*
+ * While most USB host controllers implement their registers in
+ * little-endian format, a minority (celleb companion chip) implement
+ * them in big endian format.
+ *
+ * This attempts to support either format at compile time without a
+ * runtime penalty, or both formats with the additional overhead
+ * of checking a flag bit.
+ */
+
+#ifdef CONFIG_USB_EHCI_BIG_ENDIAN_MMIO
+#define ehci_big_endian_mmio(e)         ((e)->big_endian_mmio)
+#else
+#define ehci_big_endian_mmio(e)         0
+#endif
+
+static inline unsigned int ehci_readl (const struct ehci_hcd *ehci,
+                                       __u32 __iomem * regs)
+{
+        return ehci_big_endian_mmio(ehci) ?
+                readl_be((__force u32 *)regs) :
+                readl((__force u32 *)regs);
+}
+
+static inline void ehci_writel (const struct ehci_hcd *ehci,
+                                const unsigned int val, __u32 __iomem *regs)
+{
+        ehci_big_endian_mmio(ehci) ?
+                writel_be(val, (__force u32 *)regs) :
+                writel(val, (__force u32 *)regs);
+}
 
 /*-------------------------------------------------------------------------*/