Jordan Crouse writes:
I guess I should provide a bit of context for this code. When the 5535
(the predecessor to the 5536) first came out, the BIOS folks decided
to combine some of the "random" legacy devices as bars under what
we call the ISA_BRIDGE device, and it has been that way until this day.
This has been very frustrating, since it doesn't mesh very well with
the Linux PCI model. To get around that - most of the drivers have
either read the resource base directly from the 5536 MSRs (such as the
cs5535_gpio driver), and others like the SMBUS driver have probed for the
PCI devices, but not actually used them. The SMBUS driver is particularly
confusing because the same block was accessible through ISA ports in
earlier generations of the Geode, so we have to do way more probing
then one would expect.
This driver was an effort to provide some place to manage the PCI device,
particularly for power management purposes. In the end, its like we are
designing our own API for our own bus, but we're really hijacking
existing infrastructure, which seemed easier to me then creating a new
device type from scratch just for the Geode.
When faced with this, I'd just provide config space accessor functions
that make things look normal. See arch/i386/pci for where you set that.
Call something that does:
raw_pci_ops = pci_geode_access;
You'll have one of these:
static struct pci_raw_ops pci_geode_access = {
.read = pci_geode_read,
.write = pci_geode_write
};
Those functions can of course call the normal functions if it helps any.
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