Hello.
Alan Cox wrote:
The IDE interface of the Geode CS5536 companion chip is a completely
different beast. It's a more or less standard AMD 8111 PCI IDE device
with slightly different timings.
I'm not sure I uderstand the passage about "slightly different
timings"...
The timing values used are different to those on the AMD 8111 even though
the interface is similar.
What do you mean by timing values anyway, clock counts or the register
encoding itself?
It's stange that the driver is using CPI config. space by default
which not even documented in the datasheet. I guess the MSR accesses are
The PCI configuration is the portable way to drive it.
Portable to what? As you have yorself noted below, this is Geode -- and I
highly doubt that CS5536 will be used for anything else.
also somewhat faster because one doesn't have to access the address/data
register pair at ports 0xcf8/0xcfc...
This is a Geode.
I know. :-)
I have hacked on older Geode GX2 for some time back in 2004 (although not
on something related to PCI); my "toy" board has RIP just recently.)
What makes you think there is even a PCI bus
I sure know that it's not PCI (IIUC, it's the common tendency in the x86
north-to-south-bridge busses has been emulating the PCI config. space with
less and less PCI compatible "physical layer"). That does mean emulating PCI
config. space mechanism #1 and Geode's not an exception here, see:
http://www.amd.com/files/connectivitysolutions/geode/geode_gx/32663C_lx_gx_pciconfig.pdf
or that the 8111 interface isn't entirely a software construct.
If that's the case (looks like so), it makes using it even appealing...
Geode PCI hardware is mostly smoke and mirrors ;)
When it comes to their internal controllers, yes (though e.g. their OHCI
seem to have the real PCI config. space).
Alan
WBR, Sergei
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