On 04/05/11 21:59, Alan Stern wrote:
> On Wed, 4 May 2011, Jan Andersson wrote:
>
>> This patch is part of a series that extend the UHCI HCD to support
>> non-PCI controllers.
>>
>> This patch moves PCI specific functions to uhci-pci.c and includes
>> this file in uhci-hcd.c. It also renames the function uhci_init to
>> uhci_pci_init.
>
> ...
>
>> -static int uhci_init(struct usb_hcd *hcd)
>> -{
>> - struct uhci_hcd *uhci = hcd_to_uhci(hcd);
>> - unsigned io_size = (unsigned) hcd->rsrc_len;
>> - int port;
>> -
>> - uhci->io_addr = (unsigned long) hcd->rsrc_start;
>> -
>> - /* The UHCI spec says devices must have 2 ports, and goes on to say
>> - * they may have more but gives no way to determine how many there
>> - * are. However according to the UHCI spec, Bit 7 of the port
>> - * status and control register is always set to 1. So we try to
>> - * use this to our advantage. Another common failure mode when
>> - * a nonexistent register is addressed is to return all ones, so
>> - * we test for that also.
>> - */
>> - for (port = 0; port < (io_size - USBPORTSC1) / 2; port++) {
>> - unsigned int portstatus;
>> -
>> - portstatus = inw(uhci->io_addr + USBPORTSC1 + (port * 2));
>> - if (!(portstatus & 0x0080) || portstatus == 0xffff)
>> - break;
>> - }
>> - if (debug)
>> - dev_info(uhci_dev(uhci), "detected %d ports\n", port);
>> -
>> - /* Anything greater than 7 is weird so we'll ignore it. */
>> - if (port > UHCI_RH_MAXCHILD) {
>> - dev_info(uhci_dev(uhci), "port count misdetected? "
>> - "forcing to 2 ports\n");
>> - port = 2;
>> - }
>> - uhci->rh_numports = port;
>
> This port-detection logic will be common to all platforms. It should
> remain in uhci-hcd as a subroutine that can be called from the
> platform-specific init routine.
>
Good idea. Will do.
Best regards,
Jan
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