| Message ID | 20220930192747.21471-2-vidyas@nvidia.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere, archived |
| Delegated to: | Rob Herring |
| Headers | show |
| Series | GPIO based PCIe Hot-Plug support | expand |
On Sat, Oct 01, 2022 at 12:57:44AM +0530, Vidya Sagar wrote: > Provide a way for the firmware to tell the OS about the GPIO that can be > used to get the Hot-Plug and Unplug events. [...] > --- a/Documentation/devicetree/bindings/pci/pci.txt > +++ b/Documentation/devicetree/bindings/pci/pci.txt > @@ -32,6 +32,10 @@ driver implementation may support the following properties: > 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. > +- hotplug-gpios: > + If present this property specifies the GPIO to be used for Hot-Plug/Unplug > + functionality. It is used by the PCIe GPIO Hot-Plug core driver for > + PCIe device Hot-Plug/Unplug events. Please specify the GPIO's semantics in more detail: Is the pin high as long as presence of a card is detected? Or does it pulse when a hotplug/unplug event occurs? Thanks, Lukas
On Saturday 01 October 2022 17:56:26 Lukas Wunner wrote: > On Sat, Oct 01, 2022 at 12:57:44AM +0530, Vidya Sagar wrote: > > Provide a way for the firmware to tell the OS about the GPIO that can be > > used to get the Hot-Plug and Unplug events. > [...] > > --- a/Documentation/devicetree/bindings/pci/pci.txt > > +++ b/Documentation/devicetree/bindings/pci/pci.txt > > @@ -32,6 +32,10 @@ driver implementation may support the following properties: > > 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. > > +- hotplug-gpios: > > + If present this property specifies the GPIO to be used for Hot-Plug/Unplug > > + functionality. It is used by the PCIe GPIO Hot-Plug core driver for > > + PCIe device Hot-Plug/Unplug events. > > Please specify the GPIO's semantics in more detail: > Is the pin high as long as presence of a card is detected? Hello! In PCIe is this semantics called "Presence Detect" (see PCIe Slot Capabilities). So should it be rather named "presence-detect-gpios" instead of hotplug? > Or does it pulse when a hotplug/unplug event occurs? > > Thanks, > > Lukas
diff --git a/Documentation/devicetree/bindings/pci/pci.txt b/Documentation/devicetree/bindings/pci/pci.txt index 6a8f2874a24d..7b89bddc8dde 100644 --- a/Documentation/devicetree/bindings/pci/pci.txt +++ b/Documentation/devicetree/bindings/pci/pci.txt @@ -32,6 +32,10 @@ driver implementation may support the following properties: 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. +- hotplug-gpios: + If present this property specifies the GPIO to be used for Hot-Plug/Unplug + functionality. It is used by the PCIe GPIO Hot-Plug core driver for + PCIe device Hot-Plug/Unplug events. PCI-PCI Bridge properties -------------------------
Provide a way for the firmware to tell the OS about the GPIO that can be used to get the Hot-Plug and Unplug events. Signed-off-by: Vidya Sagar <vidyas@nvidia.com> --- Documentation/devicetree/bindings/pci/pci.txt | 4 ++++ 1 file changed, 4 insertions(+)