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]. 

The initial idea is to adopt the Manivannan���s recent PCIe M.2 KeyE
connector support patch set[3] and PCI power control framework patches[2],
and extend them to the pcie-imx6 driver. Since the new M.2/pwrctrl model is
implemented based on Root Ports and requires the pwrctrl driver to bind to
a Root Port device, we need to introduce a Root Port child node on i.MX
boards that provide an M.2 connector.

To follow a more standardized DT structure, it also makes sense to move
the reset-gpios and wake-gpios properties into the Root Port node. These
signals logically belong to the Root Port rather than the host bridge,
and placing them there aligns with the new M.2/pwrctrl model.

Regarding backward compatibility, as Frank suggested, I will not remove
the old reset-gpio property from existing DTS files to avoid function
break.

For new i.MX platforms ��� such as the upcoming i.MX952-evk will add
vpcie-supply, reset-gpios, and wake-gpios directly under the Root Port
node.
Therefore, driver updates are needed to support both the legacy
properties and the new standardized Root Port based layout.

[1] https://lore.kernel.org/linux-pci/20250702-perst-v5-0-920b3d1f6ee1@qti.qualcomm.com/ (local)
[2] https://lore.kernel.org/linux-pci/20260115-pci-pwrctrl-rework-v5-0-9d26da3ce903@oss.qualcomm.com/ (local)
[3] https://lore.kernel.org/linux-pci/20260112-pci-m2-e-v4-0-eff84d2c6d26@oss.qualcomm.com/ (local)

Signed-off-by: Sherry Sun <redacted>
---
Changes in V2:
1. Improve the patch#2 commit message as Frank suggested.
2. Add Reviewed-by tag for patch#1.

Changes in V2:
1. Improve the patch#1 commit message as Frank suggested.
2. Also mark the reset-gpio-active-high property as deprecated in
   imx6q-pcie DT binding as Rob suggested.
3. The imx_pcie_delete_ports() has been moved up so that the
   imx_pcie_parse_ports() can call this helper function in error handling.
4. Keep the old reset-gpio property in the host bridge node for the
   existing dts files and add comments to avoid confusion.
---

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 PERST property
  arm: dts: imx6sx: Add Root Port node and PERST property
  arm: dts: imx7d: Add Root Port node and PERST property
  arm64: dts: imx8mm: Add Root Port node and PERST property
  arm64: dts: imx8mp: Add Root Port node and PERST property
  arm64: dts: imx8mq: Add Root Port node and PERST property
  arm64: dts: imx8dxl/qm/qxp: Add Root Port node and PERST property
  arm64: dts: imx95: Add Root Port node and PERST property

 .../bindings/pci/fsl,imx6q-pcie.yaml          |  32 +++++
 .../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         | 123 ++++++++++++++++--
 23 files changed, 348 insertions(+), 14 deletions(-)

-- 
2.37.1