PCI: imx6: Clear CLKREQ# override if 'supports-clkreq' DT property is available

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CLKREQ# is an optional reference clock request signal defined by the PCIe
CEM and M.2 specifications to request REFCLK and exit the L1 Substates. The
imx6 controller driver so far forced the CLKREQ# signal to low by enabling
the CLKREQ# override logic as the slots do not expose this signal.

Now, there are board designs coming up exposing this signal to the endpoint
devices. This is identified using the 'supports-clkreq' DT property in the
controller node.

So when the DT node has this property, clear the CLKREQ# override after
link up in host_post_init() callback to allow the endpoint to drive the
CLKREQ# signal.

Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
[mani: squashed the imx8mm_pcie_clkreq_override helper patch & reworded description]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>

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Richard Zhu 2026-01-06 17:19:19 +05:30 • committed by Manivannan Sadhasivam

parent 27a064aba2

commit a152a90f53

1 changed files with 29 additions and 1 deletions

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drivers/pci/controller/dwc/pci-imx6.c

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