Re: [PATCH 00/10] pci-imx6: Add support for parsing the reset property in new Root Port binding

[Bjorn Helgaas <helgaas@kernel.org>]

On Mon, Jan 19, 2026 at 06:02:25PM +0800, Sherry Sun wrote:
> This patch set adds support for parsing the reset property in new Root Port
> binding in pci-imx6 driver, similar to the implementation in the qcom pcie
> driver[1].
> 
> The plan is to add the wake-gpio property to the root port in subsequent
> patches. Also, the vpcie-supply property will be moved to the root port
> node later based on the refactoring patch set for the PCI pwrctrl
> framework[2]. 
> 
> [1] https://lore.kernel.org/linux-pci/20250702-perst-v5-0-920b3d1f6ee1@qti.qualcomm.com/
> [2] https://lore.kernel.org/linux-pci/20260115-pci-pwrctrl-rework-v5-0-9d26da3ce903@oss.qualcomm.com/

Is there value in doing this?  It looks like it might be making work
for no benefit.

Certainly for *new* drivers and DTs, we should put resets in the Root
Port.  But this looks like you're moving them in existing DTs.  In
that case, you still have to support the old DTs where the resets are
in the host bridge.

If you are adding support for hardware that has multiple Root Ports
with separate resets for each Root Port, then of course you would need
to put the reset info in per-Root Port stanzas and make changes to
support that, but this series doesn't mention anything about multiple
Root Ports.

> Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
> ---
> Sherry Sun (10):
>   dt-bindings: PCI: fsl,imx6q-pcie: Add reset GPIO in Root Port node
>   PCI: imx6: Add support for parsing the reset property in new Root Port
>     binding
>   arm: dts: imx6qdl: Add Root Port node and move PERST property to Root
>     Port node
>   arm: dts: imx6sx: Add Root Port node and move PERST property to Root
>     Port node
>   arm: dts: imx7d: Add Root Port node and move PERST property to Root
>     Port node
>   arm64: dts: imx8mm: Add Root Port node and move PERST property to Root
>     Port node
>   arm64: dts: imx8mp: Add Root Port node and move PERST property to Root
>     Port node
>   arm64: dts: imx8mq: Add Root Port nodes and move PERST property to
>     Root Port node
>   arm64: dts: imx8dxl/qm/qxp: Add Root Port nodes and move PERST
>     property to Root Port node
>   arm64: dts: imx95: Add Root Port nodes and move PERST property to Root
>     Port node
> 
>  .../bindings/pci/fsl,imx6q-pcie.yaml          |  29 ++++
>  .../arm/boot/dts/nxp/imx/imx6qdl-sabresd.dtsi |   5 +-
>  arch/arm/boot/dts/nxp/imx/imx6qdl.dtsi        |  11 ++
>  .../arm/boot/dts/nxp/imx/imx6qp-sabreauto.dts |   5 +-
>  arch/arm/boot/dts/nxp/imx/imx6sx-sdb.dtsi     |   5 +-
>  arch/arm/boot/dts/nxp/imx/imx6sx.dtsi         |  11 ++
>  arch/arm/boot/dts/nxp/imx/imx7d-sdb.dts       |   5 +-
>  arch/arm/boot/dts/nxp/imx/imx7d.dtsi          |  11 ++
>  .../boot/dts/freescale/imx8-ss-hsio.dtsi      |  11 ++
>  arch/arm64/boot/dts/freescale/imx8dxl-evk.dts |   5 +-
>  arch/arm64/boot/dts/freescale/imx8mm-evk.dtsi |   5 +-
>  arch/arm64/boot/dts/freescale/imx8mm.dtsi     |  11 ++
>  arch/arm64/boot/dts/freescale/imx8mp-evk.dts  |   5 +-
>  arch/arm64/boot/dts/freescale/imx8mp.dtsi     |  11 ++
>  arch/arm64/boot/dts/freescale/imx8mq-evk.dts  |  10 +-
>  arch/arm64/boot/dts/freescale/imx8mq.dtsi     |  22 +++
>  arch/arm64/boot/dts/freescale/imx8qm-mek.dts  |  10 +-
>  .../boot/dts/freescale/imx8qm-ss-hsio.dtsi    |  22 +++
>  arch/arm64/boot/dts/freescale/imx8qxp-mek.dts |   5 +-
>  .../boot/dts/freescale/imx95-15x15-evk.dts    |   5 +-
>  .../boot/dts/freescale/imx95-19x19-evk.dts    |  10 +-
>  arch/arm64/boot/dts/freescale/imx95.dtsi      |  22 +++
>  drivers/pci/controller/dwc/pci-imx6.c         | 128 ++++++++++++++++--
>  23 files changed, 335 insertions(+), 29 deletions(-)
> 
> -- 
> 2.37.1
>