bindings/pci/pci.txt

3 PCI Bus Binding to: IEEE Std 1275-1994
4 https://www.devicetree.org/open-firmware/bindings/pci/pci2_1.pdf
9 https://www.devicetree.org/open-firmware/practice/imap/imap0_9d.pdf
14 - linux,pci-domain:
15    If present this property assigns a fixed PCI domain number to a host bridge,
18    host bridges in the system, otherwise potentially conflicting domain numbers
19    may be assigned to root buses behind different host bridges.  The domain
21 - max-link-speed:
27 - reset-gpios:
30 - supports-clkreq:
34    not to advertise ASPM L1 Sub-States support if there is no CLKREQ signal.
36 PCI-PCI Bridge properties
37 -------------------------
46 - reg:
47    Identifies the PCI-PCI bridge. As defined in the IEEE Std 1275-1994
48    document, it is a five-cell address encoded as (phys.hi phys.mid
56    number of a root port is the first number in the bus-range property,
60    above this port, then phys.hi contains the 8-bit function number as
63    OS is ARI-aware.
67 - external-facing:
68    When present, the port is external-facing. All bridges and endpoints
71    trusted with relaxed DMA protection, as users could easily attach
77 	compatible = "pci-host-ecam-generic";
80 		/* Root port 00:01.0 is external-facing */
82 		external-facing;