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Diffstat (limited to 'Documentation/devicetree/bindings/pci/pci.txt')
-rw-r--r-- | Documentation/devicetree/bindings/pci/pci.txt | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/pci/pci.txt b/Documentation/devicetree/bindings/pci/pci.txt new file mode 100644 index 000000000..c77981c5d --- /dev/null +++ b/Documentation/devicetree/bindings/pci/pci.txt @@ -0,0 +1,26 @@ +PCI bus bridges have standardized Device Tree bindings: + +PCI Bus Binding to: IEEE Std 1275-1994 +http://www.devicetree.org/open-firmware/bindings/pci/pci2_1.pdf + +And for the interrupt mapping part: + +Open Firmware Recommended Practice: Interrupt Mapping +http://www.devicetree.org/open-firmware/practice/imap/imap0_9d.pdf + +Additionally to the properties specified in the above standards a host bridge +driver implementation may support the following properties: + +- linux,pci-domain: + If present this property assigns a fixed PCI domain number to a host bridge, + otherwise an unstable (across boots) unique number will be assigned. + It is required to either not set this property at all or set it for all + host bridges in the system, otherwise potentially conflicting domain numbers + may be assigned to root buses behind different host bridges. The domain + number for each host bridge in the system must be unique. +- max-link-speed: + If present this property specifies PCI gen for link capability. Host + drivers could add this as a strategy to avoid unnecessary operation for + unsupported link speed, for instance, trying to do training for + unsupported link speed, etc. Must be '4' for gen4, '3' for gen3, '2' + for gen2, and '1' for gen1. Any other values are invalid. |