Re: Fwd: hpet patches

From: Jon Smirl
Date: Wed Jun 15 2005 - 12:55:37 EST


On 6/15/05, Pallipadi, Venkatesh <venkatesh.pallipadi@xxxxxxxxx> wrote:
> The specification for ICH5 has the details about this address
> http://www.intel.com/design/chipsets/datashts/25251601.pdf (Chapter 17).
> We need to look at specific device address to figure out the HPET base
> address in this case.

The ICH5 fix up needs to look something like this:
PCI_DEVICE_ID_INTEL_82801EB_0 is the PCI ID for the LPC device.

ACPI_FIXUP(INTEL, PCI_DEVICE_ID_INTEL_82801EB_0, hpet_ich5_fixup)
hpet_ich5_fixup()
{
pci_bios_find_device(PCI_ID_INTEL, PCI_DEVICE_ID_INTEL_82801EB_0, ...)
pci_bios_read(device, GENERAL_CONTROL_REGISTER, ..)
Check bit 17 and see if it is enabled
use bit 15:16 to set hpet_address to one of the four addresses
}

It would be more complicated to try and turn it on if it is turned
off. Mine is turned on at boot even though it has no ACPI entry. A
routine like this should at least get things started.

--
Jon Smirl
jonsmirl@xxxxxxxxx
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