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>
diff --git a/drivers/usb/host/ohci.h b/drivers/usb/host/ohci.h
index dd4d5b4..47c5c66 100644
--- a/drivers/usb/host/ohci.h
+++ b/drivers/usb/host/ohci.h
@@ -398,6 +398,7 @@
#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 @@
/* 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 @@
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);