int
pci_get_capability(pci_chipset_tag_t pc, pcitag_t tag, int capid,
int *offset, pcireg_t *value)
{
pcireg_t reg;
unsigned int ofs;
reg = pci_conf_read(pc, tag, PCI_COMMAND_STATUS_REG);
if (!(reg & PCI_STATUS_CAPLIST_SUPPORT))
return 0;
/* Determine the Capability List Pointer register to start with. */
reg = pci_conf_read(pc, tag, PCI_BHLC_REG);
switch (PCI_HDRTYPE_TYPE(reg)) {
case 0: /* standard device header */
case 1: /* PCI-PCI bridge header */
ofs = PCI_CAPLISTPTR_REG;
break;
case 2: /* PCI-CardBus Bridge header */
ofs = PCI_CARDBUS_CAPLISTPTR_REG;
break;
default:
return 0;
}
ofs = PCI_CAPLIST_PTR(pci_conf_read(pc, tag, ofs));
while (ofs != 0) {
if ((ofs & 3) || (ofs < 0x40)) {
int bus, device, function;
pci_decompose_tag(pc, tag, &bus, &device, &function);
printf("Skipping broken PCI header on %d:%d:%d\n",
bus, device, function);
break;
}
reg = pci_conf_read(pc, tag, ofs);
if (PCI_CAPLIST_CAP(reg) == capid) {
if (offset)
*offset = ofs;
if (value)
*value = reg;
return 1;
}
ofs = PCI_CAPLIST_NEXT(reg);
}
return 0;
}
int
pciaddr_device_is_agp(pci_chipset_tag_t pc, pcitag_t tag)
{
pcireg_t class, status, rval;
int off;
/* Check AGP device. */
class = pci_conf_read(pc, tag, PCI_CLASS_REG);
if (PCI_CLASS(class) == PCI_CLASS_DISPLAY) {
status = pci_conf_read(pc, tag, PCI_COMMAND_STATUS_REG);
if (status & PCI_STATUS_CAPLIST_SUPPORT) {
rval = pci_conf_read(pc, tag, PCI_CAPLISTPTR_REG);
for (off = PCI_CAPLIST_PTR(rval);
off != 0;
off = PCI_CAPLIST_NEXT(rval) ) {
rval = pci_conf_read(pc, tag, off);
if (PCI_CAPLIST_CAP(rval) == PCI_CAP_AGP)
return (1);
}
}
}
return (0);
}
