Am 12.12.2010 um 00:22 schrieb Benjamin Herrenschmidt:
On Sat, 2010-12-11 at 18:06 +0200, Gleb Natapov wrote:
http://playground.sun.com/pub/p1275/bindings/pci/pci2_1.pdf has table on page 10 that defines how pci class code should be translated into OF name. This is what my patch is using. pci-ata does not look spec compliant (or is there more up-to-date spec?)
What should we dowith
ata-2@600 vs drive@1?
There is no available IDE OF binding spec, so I when with the way OpenBIOS reports ata on qemu-x86. I have no idea what 600 in ata-2@600 may mean, but looking at g3_beige_300.html there is no such node there and looking at any other device tree in http://penguinppc.org/historical/dev-trees-html/
Those are old and I wouldn't look too closely at what Apple does.
The only working system emulation we have are Macs (G3 beige, G4, G5), so we can't just ignore Apple. Alex even made me stick to their odd 0x41 rtas-version property. ;)
ATA doesn't really need anything complex, mostly the ata controller, generally named "ata" nowadays with a #address-cells of 1 and a #size-cells of 0. Children are then typically disk, cdrom, ... (ie block devices) with a unit address of 0 for master and 1 for slave.
In the case of controllers with multiple ports, typically you have one such "ata" node per bus. "pci-ata" is a liberal use by Apple here representing the actual host controller PCI device.
In any case, what matters is the "compatible" property. This is what defines the programming interface of a device.
I haven't found one that use this kind of addressing for pci-ata. http://penguinppc.org/historical/dev-trees-html/g3bw_400.html for instance has pci@80000000/pci-bridge@d/pci-ata@1/ata-4. ata-2@600 kind of addressing is used by devices on mac-io bus which I do not think we emulate in qemu. So it looks like OpneBIOS is wrong here.
Well, it's possible that the @600 represents a register offset within pci-ata, this is entirely up to pci-ata to do as it wishes there to define it's own internal binding. Is there a "ranges" property defining translation accross "pci-ata" ?
No, but that may be OpenBIOS' fault. Here's its reg, in case it helps:
reg 00001800 00000000 00000000 00000000 00000000 01001810 00000000 00000000 00000000 00000008 01001814 00000000 00000000 00000000 00000004 01001818 00000000 00000000 00000000 00000008 0100181c 00000000 00000000 00000000 00000004 01001820 00000000 00000000 00000000 00000010
Regards, Andreas