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