[OLPC-devel] Re: just verified: 2306 + olpc + linux kernel works.

[Jordan Crouse]

On 26/05/06 00:13 +0100, David Woodhouse wrote:
> On Thu, 2006-05-25 at 20:00 -0300, Marcelo Tosatti wrote:
> > 
> > Ah, to disable PCI you want to comment this code in drivers/mtd/nand/cs553x.c:
> > 
> > static int __init cs553x_init(void)
> > {
> >         /* Check whether we actually have a CS5535 or CS5536 */
> > #if 0
> >         if (!pci_find_device(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA, NULL) &&
> >             !pci_find_device(PCI_VENDOR_ID_NS,  PCI_DEVICE_ID_NS_CS5535_ISA, NULL))
> >                 return -ENXIO;
> > #endif
> 
> We should find a better way of detecting the CS553[56] companion chip.
> We can check for a Geode easily enough -- given that knowledge, can we
> check certain MSRs to see if the companion chip is present?
> 
> Or can we just assume that there's a CS553x if it's certain models of
> Geode?

You *can* assume that the GX/LX will have a CS553x hanging about, but if you
want to be super sure, you can check for the device IDs on the DIVIL
device capabilities MSR (0x51400000):

	CS5535: 0x00000000 0x002DF0xx
	CS5536: 0x00000000 0x005DF5xx

In both cases, xx will indicate the revision of the chip.   If the DIVIL
device exists, and the IDs match, you can be certain its a 5535 or 5536.

Jordan

--
Jordan Crouse
Senior Linux Engineer
AMD - Personal Connectivity Solutions Group
<www.amd.com/embeddedprocessors>