[PATCH 0/9] PCI-EP: Add 'ranges' support for PCI endpoint devices

[Frank Li <Frank.Li@nxp.com>]

The PCI bus device tree supports 'ranges' properties that indicate
how to convert PCI addresses to CPU addresses. Many PCI controllers
are dual-role controllers, supporting both Root Complex (RC) and
Endpoint (EP) modes. The EP side also needs similar information for
proper address translation.

This commit introduces several changes to add 'ranges' support for
PCI endpoint devices:

1. **Modify of_address.c**: Add support for the new `device_type`
   "pci-ep", enabling it to parse 'ranges' using the same functions
   as for PCI devices.

2. **Update DesignWare PCIe EP driver**: Enhance the driver to
   support 'ranges' when 'addr_space' is missing, maintaining
   compatibility with existing drivers.

3. **Update binding documentation**: Modify the device tree bindings
   to include 'ranges' support and make 'addr_space' an optional
   entry in 'reg-names'.

4. **Add i.MX8QXP EP support**: Incorporate support for the
   i.MX8QXP PCIe EP in the driver.

i.MX8QXP PCIe dts is upstreaming.  Below is pcie-ep part.

pcieb_ep: pcie-ep@5f010000 {
                compatible = "fsl,imx8q-pcie-ep";
                reg = <0x5f010000 0x00010000>;
                reg-names = "dbi";
                #address-cells = <3>;
                #size-cells = <2>;
                device_type = "pci-ep";
                ranges = <0x82000000 0 0x80000000 0x70000000 0 0x10000000>;
                num-lanes = <1>;
                interrupts = <GIC_SPI 104 IRQ_TYPE_LEVEL_HIGH>;
                interrupt-names = "dma";
                clocks = <&pcieb_lpcg IMX_LPCG_CLK_6>,
                         <&pcieb_lpcg IMX_LPCG_CLK_4>,
                         <&pcieb_lpcg IMX_LPCG_CLK_5>;
                clock-names = "dbi", "mstr", "slv";
                power-domains = <&pd IMX_SC_R_PCIE_B>;
                fsl,max-link-speed = <3>;
                num-ib-windows = <6>;
                num-ob-windows = <6>;
                status = "disabled";
};

These changes improve PCIe EP support by allowing proper address
translation using 'ranges', ensuring compatibility with devices that
rely on this information.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
Frank Li (9):
      dt-bindings: PCI: pci-ep: Document 'ranges' property
      of: address: Add argument 'name' for of_node_is_pcie()
      of: address: Add device type pci-ep
      dt-bindings: PCI: snps,dw-pcie-ep: 'addr_space' not required if 'ranges' present
      PCI: dwc: ep: Replace phys_base and addr_size with range
      PCI: dwc: ep: Use 'ranges' from DT if 'addr_space' is missing
      dt-bindings: PCI: fsl,imx6q-pcie-ep: Add compatible string fsl,imx8q-pcie-ep
      PCI: imx6: Pass correct sub mode when calling phy_set_mode_ext()
      PCI: imx6: Add i.MX8Q PCIe Endpoint (EP) support

 .../devicetree/bindings/pci/fsl,imx6q-pcie-ep.yaml | 42 +++++++++++++++++++++-
 Documentation/devicetree/bindings/pci/pci-ep.yaml  | 30 ++++++++++++++++
 .../bindings/pci/snps,dw-pcie-common.yaml          |  4 +--
 .../devicetree/bindings/pci/snps,dw-pcie-ep.yaml   | 21 ++++++++---
 drivers/of/address.c                               | 30 ++++++++++++----
 drivers/pci/controller/dwc/pci-imx6.c              | 24 ++++++++++++-
 drivers/pci/controller/dwc/pcie-artpec6.c          |  2 +-
 drivers/pci/controller/dwc/pcie-designware-ep.c    | 23 ++++++++----
 drivers/pci/controller/dwc/pcie-designware.h       |  4 +--
 9 files changed, 157 insertions(+), 23 deletions(-)
---
base-commit: 909eac36208b70a22fd0d1c3097e3af98dca7599
change-id: 20240918-pcie_ep_range-4c5c5e300e19

Best regards,
---
Frank Li <Frank.Li@nxp.com>