Driver Devel: Cardbus BAR Mapping/PCI Differences

[Phil Quinton <pquinton_(_at_)_softhome_(_dot_)_net>]

Hi,

 I'm currently trying to migrate the satalink driver to Cardbus on 
NetBSD, and I'm having difficulty getting detailed answers from their 
mailling list and I noticed OpenBSD Cardbus code is based on the NetBSD 
code but more upto date. So here goes with my questions:

1) When a Cardbus driver maps a BAR with Cardbus_mapreg_map, the 
returned bus_addr is later on OR'd with say CARDBUS_MAPREG_TYPE_MEM as 
used in the mapreg_map call, and Cardbus_conf_write'n back to the BAR.

Why?

2) Also, how would this work with a card that uses two BAR's.. satalink 
uses BA5 and the pciide code uses BA4 (I think). Would I need to write 
back the BAR's bus_addr, once mapped, for both?

3) I also notice that which ever CARDBUS_MAPREG_TYPE(IO MEM) is used as 
a guide to "make sure the right access type is on the Cardbus bridge" 
(as per driver comments). What if I wanted to map IO on one BAR and MEM 
on another.. how does this effect the value written to the bridge, using 
(*ct->ct_cf->cardbus_ctrl)?

Any advice is greatly appreciated,
Thanks for your time.

Phil Quinton.