From: Vidya Sagar Date: Tue, 13 Aug 2019 11:36:23 +0000 (+0530) Subject: dt-bindings: Add PCIe supports-clkreq property X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=7b31a72e7195aebd620d504f28b97ad8398e95ec;p=linux.git dt-bindings: Add PCIe supports-clkreq property Some host controllers need to know the existence of clkreq signal routing to downstream devices to be able to advertise low power features like ASPM L1 substates. Without clkreq signal routing being present, enabling ASPM L1 substates might lead to downstream devices being disconnected from the bus. Hence a new device tree property 'supports-clkreq' is added to make such host controllers aware of clkreq signal routing to downstream devices. Signed-off-by: Vidya Sagar Signed-off-by: Lorenzo Pieralisi Reviewed-by: Rob Herring Reviewed-by: Thierry Reding --- diff --git a/Documentation/devicetree/bindings/pci/pci.txt b/Documentation/devicetree/bindings/pci/pci.txt index 2a5d91024059c..29bcbd88f457d 100644 --- a/Documentation/devicetree/bindings/pci/pci.txt +++ b/Documentation/devicetree/bindings/pci/pci.txt @@ -27,6 +27,11 @@ driver implementation may support the following properties: - reset-gpios: If present this property specifies PERST# GPIO. Host drivers can parse the GPIO and apply fundamental reset to endpoints. +- supports-clkreq: + If present this property specifies that CLKREQ signal routing exists from + root port to downstream device and host bridge drivers can do programming + which depends on CLKREQ signal existence. For example, programming root port + not to advertise ASPM L1 Sub-States support if there is no CLKREQ signal. PCI-PCI Bridge properties -------------------------