USB: add runtime frame_no quirk for big-endian OHCI

Add OHCI big endian frame_no quirk.  The frame_no value stored in the
HCCA is a 16 bit field at a specific offset, but since not all CPUs can
do 16-bit memory accesses it's used as a 32 bit field.  And that's why
big-endian OHCI must shift 16 bits ... unless the spec is not followed.

Currently there's one MPC52xx platform that doesn't need the shift. This
patch adds a new "big endian frame_no" quirk to control that at runtime.

Signed-off-by: Valentine Barshak <vbarshak@ru.mvista.com>
Acked-by: Dale Farnsworth <dale@farnsworth.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 15 insertions, 8 deletions

diff --git a/drivers/usb/host/ohci-ppc-of.c b/drivers/usb/host/ohci-ppc-of.c
index c43b66acd4d5..0a7426920150 100644
--- a/drivers/usb/host/ohci-ppc-of.c
+++ b/drivers/usb/host/ohci-ppc-of.c
@@ -134,8 +134,11 @@ ohci_hcd_ppc_of_probe(struct of_device *op, const struct of_device_id *match)
         }
 
         ohci = hcd_to_ohci(hcd);
-        if (is_bigendian)
+        if (is_bigendian) {
                 ohci->flags |= OHCI_QUIRK_BE_MMIO | OHCI_QUIRK_BE_DESC;
+                if (of_device_is_compatible(dn, "mpc5200-ohci"))
+                        ohci->flags |= OHCI_QUIRK_FRAME_NO;
+        }
 
         ohci_hcd_init(ohci);
 
diff --git a/drivers/usb/host/ohci-ppc-soc.c b/drivers/usb/host/ohci-ppc-soc.c
index 1a2e1777ca61..f95be1896b0d 100644
--- a/drivers/usb/host/ohci-ppc-soc.c
+++ b/drivers/usb/host/ohci-ppc-soc.c
@@ -73,6 +73,11 @@ static int usb_hcd_ppc_soc_probe(const struct hc_driver *driver,
 
         ohci = hcd_to_ohci(hcd);
         ohci->flags |= OHCI_QUIRK_BE_MMIO | OHCI_QUIRK_BE_DESC;
+
+#ifdef CONFIG_PPC_MPC52xx
+        /* MPC52xx doesn't need frame_no shift */
+        ohci->flags |= OHCI_QUIRK_FRAME_NO;
+#endif
         ohci_hcd_init(ohci);
 
         retval = usb_add_hcd(hcd, irq, IRQF_DISABLED);
diff --git a/drivers/usb/host/ohci.h b/drivers/usb/host/ohci.h
index dd4d5b4dcb6c..47c5c66a282c 100644
--- a/drivers/usb/host/ohci.h
+++ b/drivers/usb/host/ohci.h
@@ -398,6 +398,7 @@ struct ohci_hcd {
 #define OHCI_QUIRK_BE_MMIO      0x10                    /* BE registers */
 #define OHCI_QUIRK_ZFMICRO      0x20                    /* Compaq ZFMicro chipset*/
 #define OHCI_QUIRK_NEC          0x40                    /* lost interrupts */
+#define OHCI_QUIRK_FRAME_NO     0x80                    /* no big endian frame_no shift */
         // there are also chip quirks/bugs in init logic
 
         struct work_struct      nec_work;       /* Worker for NEC quirk */
@@ -633,15 +634,12 @@ static inline u32 hc32_to_cpup (const struct ohci_hcd *ohci, const __hc32 *x)
 /* HCCA frame number is 16 bits, but is accessed as 32 bits since not all
  * hardware handles 16 bit reads.  That creates a different confusion on
  * some big-endian SOC implementations.  Same thing happens with PSW access.
- *
- * FIXME: Deal with that as a runtime quirk when STB03xxx is ported over
- * to arch/powerpc
  */
 
-#ifdef CONFIG_STB03xxx
-#define OHCI_BE_FRAME_NO_SHIFT  16
+#ifdef CONFIG_PPC_MPC52xx
+#define big_endian_frame_no_quirk(ohci) (ohci->flags & OHCI_QUIRK_FRAME_NO)
 #else
-#define OHCI_BE_FRAME_NO_SHIFT  0
+#define big_endian_frame_no_quirk(ohci) 0
 #endif
 
 static inline u16 ohci_frame_no(const struct ohci_hcd *ohci)
@@ -649,7 +647,8 @@ static inline u16 ohci_frame_no(const struct ohci_hcd *ohci)
         u32 tmp;
         if (big_endian_desc(ohci)) {
                 tmp = be32_to_cpup((__force __be32 *)&ohci->hcca->frame_no);
-                tmp >>= OHCI_BE_FRAME_NO_SHIFT;
+                if (!big_endian_frame_no_quirk(ohci))
+                        tmp >>= 16;
         } else
                 tmp = le32_to_cpup((__force __le32 *)&ohci->hcca->frame_no);