How to access a device on LPC bus?

Thiemo Nordenholz listmember at thiemo.net
Sun Oct 17 04:50:17 PDT 2004


Hi there,

beginner's question, maybe: How do I, from a device driver point of view,
access a device attached to the "Low Pincount" (LPC) bus? 

I have a Winbond W83L518D card reader controller in a notebook that I want
to access. The only way I see this device at all is (on 5.3-BETA7) in
"pnpinfo -v" output, where it shows up as 

    unknown pnpinfo _HID=WEC0518 _UID=0 at handle=\_SB_.C046.C059.C140

-- I have identified it then by the Hardware ID. I do not see any more
information, especially no resource usage.

As far as I have read, the LPC bus devices can accessed just like ISA
devices. Actually, what seems to be the ACPI parent of this Winbond chip
(with handle \_SB_.C046.C059) is shown as isab0 in the devinfo output.

Now, to implement an identify function in a driver for this, I need to
access data in the controller - but I don't have any information about its
memory attachments... 
Could anyone give me a hint what to do here, some driver to look into for an
example, or just tell me that my idea of an ISA driver on fBSD is completely
wrong?

Thanks in advance,
  Thiemo

-- 
Query a PGP key server (e.g. http://www.pgp.net/) for my public key 41068629.
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