pci_host_generic_fdt.c: Add support for mapping dts nodes to PCI devices

[kd]

Summary

Some arm64 SoCs have nodes in their fdts that describe devices connected to the internal PCI bus.
One such SoC is Freescale LS1028A.
It expects the nodes to be mapped to devices enumerated using the standard PCI method.
Mapping is done by reading device and function ids from "reg" property.
Information is dts is used to describe MDIO/PHY connected to a given interface.

[andrew]

sys/dev/pci/pci_host_generic_fdt.c

395

Won't this break if there are multiple instances of this driver?

[kd]

sys/dev/pci/pci_host_generic_fdt.c

395

Whoops, you're right. The list should definitely be stored in the sc.

[andrew]

sys/dev/pci/pci_host_generic_fdt.c

429–430

Do we have macros for these? OFW_PCI_PHYS_HI_* look like what we should use.

[kd]

Use OFW_PCI_PHYS_HI_* macros and check bus number during ofw node search.