OSDev.org

Hi guys!!

I followed the procedure in this link to perform port reset:
http://forum.osdev.org/viewtopic.php?f=1&t=23318

However I can't get the port connect status change bit back to 0, it ever remains settled to 1.

What would I do here? Somebody has another UHCI reference apart the intel one??

Thank you guys.

You may find the following code helpful or look in the tatOS/usb folder for more info.

http://code.google.com/p/tatos/

TomT


;**************************************************
;uhci_portconnect and ehci_portconnect
;checks if a device is connected to a port
;input
;eax=port number starting with 0 (0,1,2,3...)
;return
;CF is set if some device is connected to the port
;**************************************************

uhci_portconnect:
pushad

mov dx,[UHCIBASEADD]
add dx,0x10 ;offset for port0, 0x12 is offset for port1
shl ax,1 ;ax=0 or 2
add dx,ax ;dx=0x10 for port 0 or 0x12 for port 1
in ax,dx ;read the port
;ax contains PORTSC

bt ax,0 ;sets CF if bit0 is set if device is present

popad
ret



ehci_portconnect:
pushad

mov ecx,eax
mov esi,[0x5d4] ;get start of ehci operational regs
mov eax,[esi+44h+ecx*4]
;eax contains PORTSC

bt ax,0 ;sets CF if bit0 is set if device is present

popad
ret

Wow!! Thank you Tom!! The SCS bit is being disabled now and I'm able to enable the port in my UHCI driver


My project is not about a OS development, is more a USB stack for SGI Irix, altough that OS/CPU architecture has some things to work on.
Thank you Tom, I will take a look to your project's code, maybe I can adapt a pair o' things into my stack