diff options
Diffstat (limited to 'drivers/usb/host/uhci-grlib.c')
| -rw-r--r-- | drivers/usb/host/uhci-grlib.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/usb/host/uhci-grlib.c b/drivers/usb/host/uhci-grlib.c index b1addd6..d01c1e2 100644 --- a/drivers/usb/host/uhci-grlib.c +++ b/drivers/usb/host/uhci-grlib.c @@ -25,6 +25,20 @@ static int uhci_grlib_init(struct usb_hcd *hcd) { struct uhci_hcd *uhci = hcd_to_uhci(hcd); + /* + * Probe to determine the endianness of the controller. + * We know that bit 7 of the PORTSC1 register is always set + * and bit 15 is always clear. If uhci_readw() yields a value + * with bit 7 (0x80) turned on then the current little-endian + * setting is correct. Otherwise we assume the value was + * byte-swapped; hence the register interface and presumably + * also the descriptors are big-endian. + */ + if (!(uhci_readw(uhci, USBPORTSC1) & 0x80)) { + uhci->big_endian_mmio = 1; + uhci->big_endian_desc = 1; + } + uhci->rh_numports = uhci_count_ports(hcd); /* Set up pointers to to generic functions */ |