linux/Documentation/devicetree/bindings/pci/snps,dw-pcie-ep.yaml

# SPDX-License-Identifier: GPL-2.0
%YAML 1.2
---
$id: http://devicetree.org/schemas/pci/snps,dw-pcie-ep.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Synopsys DesignWare PCIe endpoint interface

maintainers:
  - Jingoo Han <jingoohan1@gmail.com>
  - Gustavo Pimentel <gustavo.pimentel@synopsys.com>

description: |
  Synopsys DesignWare PCIe host controller endpoint

# Please create a separate DT-schema for your DWC PCIe Endpoint controller
# and make sure it's assigned with the vendor-specific compatible string.
select:
  properties:
    compatible:
      const: snps,dw-pcie-ep
  required:
    - compatible

allOf:
  - $ref: /schemas/pci/pci-ep.yaml#
  - $ref: /schemas/pci/snps,dw-pcie-common.yaml#

properties:
  reg:
    description:
      DBI, DBI2 reg-spaces and outbound memory window are required for the
      normal controller functioning. iATU memory IO region is also required
      if the space is unrolled (IP-core version >= 4.80a).
    minItems: 2
    maxItems: 7

  reg-names:
    minItems: 2
    maxItems: 7
    items:
      oneOf:
        - description:
            Basic DWC PCIe controller configuration-space accessible over
            the DBI interface. This memory space is either activated with
            CDM/ELBI = 0 and CS2 = 0 or is a contiguous memory region
            with all spaces. Note iATU/eDMA CSRs are indirectly accessible
            via the PL viewports on the DWC PCIe controllers older than
            v4.80a.
          const: dbi
        - description:
            Shadow DWC PCIe config-space registers. This space is selected
            by setting CDM/ELBI = 0 and CS2 = 1. This is an intermix of
            the PCI-SIG PCIe CFG-space with the shadow registers for some
            PCI Header space, PCI Standard and Extended Structures. It's
            mainly relevant for the end-point controller configuration,
            but still there are some shadow registers available for the
            Root Port mode too.
          const: dbi2
        - description:
            External Local Bus registers. It's an application-dependent
            registers normally defined by the platform engineers. The space
            can be selected by setting CDM/ELBI = 1 and CS2 = 0 wires or can
            be accessed over some platform-specific means (for instance
            as a part of a system controller).
          enum: [ elbi, app ]
        - description:
            iATU/eDMA registers common for all device functions. It's an
            unrolled memory space with the internal Address Translation
            Unit and Enhanced DMA, which is selected by setting CDM/ELBI = 1
            and CS2 = 1. For IP-core releases prior v4.80a, these registers
            have been programmed via an indirect addressing scheme using a
            set of viewport CSRs mapped into the PL space. Note iATU is
            normally mapped to the 0x0 address of this region, while eDMA
            is available at 0x80000 base address.
          const: atu
        - description:
            Platform-specific eDMA registers. Some platforms may have eDMA
            CSRs mapped in a non-standard base address. The registers offset
            can be changed or the MS/LS-bits of the address can be attached
            in an additional RTL block before the MEM-IO transactions reach
            the DW PCIe slave interface.
          const: dma
        - description:
            PHY/PCS configuration registers. Some platforms can have the
            PCS and PHY CSRs accessible over a dedicated memory mapped
            region, but mainly these registers are indirectly accessible
            either by means of the embedded PHY viewport schema or by some
            platform-specific method.
          const: phy
        - description:
            Outbound iATU-capable memory-region which will be used to
            generate various application-specific traffic on the PCIe bus
            hierarchy. It's usage scenario depends on the endpoint
            functionality, for instance it can be used to create MSI(X)
            messages.
          const: addr_space
        - description:
            Vendor-specific CSR names. Consider using the generic names above
            for new bindings.
          oneOf:
            - description: See native 'elbi/app' CSR region for details.
              enum: [ apb, link, appl ]
            - description: See native 'atu' CSR region for details.
              enum: [ atu_dma ]
    allOf:
      - contains:
          const: dbi
      - contains:
          const: addr_space

  interrupts:
    description:
      There is no mandatory IRQ signals for the normal controller functioning,
      but in addition to the native set the platforms may have a link- or
      PM-related IRQs specified.
    minItems: 1
    maxItems: 20

  interrupt-names:
    minItems: 1
    maxItems: 20
    items:
      oneOf:
        - description:
            Controller request to read or write virtual product data
            from/to the VPD capability registers.
          const: vpd
        - description:
            Link Equalization Request flag is set in the Link Status 2
            register (applicable if the corresponding IRQ is enabled in
            the Link Control 3 register).
          const: l_eq
        - description:
            Indicates that the eDMA Tx/Rx transfer is complete or that an
            error has occurred on the corresponding channel. eDMA can have
            eight Tx (Write) and Rx (Read) eDMA channels thus supporting up
            to 16 IRQ signals all together. Write eDMA channels shall go
            first in the ordered row as per default edma_int[*] bus setup.
          pattern: '^dma([0-9]|1[0-5])?$'
        - description:
            PCIe protocol correctable error or a Data Path protection
            correctable error is detected by the automotive/safety
            feature.
          const: sft_ce
        - description:
            Indicates that the internal safety mechanism has detected an
            uncorrectable error.
          const: sft_ue
        - description:
            Application-specific IRQ raised depending on the vendor-specific
            events basis.
          const: app
        - description:
            Interrupts triggered when the controller itself (in Endpoint mode)
            has sent an Assert_INT{A,B,C,D}/Desassert_INT{A,B,C,D} message to
            the upstream device.
          pattern: "^tx_int(a|b|c|d)$"
        - description:
            Combined interrupt signal raised when the controller has sent an
            Assert_INT{A,B,C,D} message. See "^tx_int(a|b|c|d)$" for details.
          const: legacy
        - description:
            Vendor-specific IRQ names. Consider using the generic names above
            for new bindings.
          oneOf:
            - description: See native "app" IRQ for details
              enum: [ intr, sys, pmc, msg, err ]

  max-functions:
    maximum: 32

required:
  - compatible
  - reg
  - reg-names

additionalProperties: true

examples:
  - |
    pcie-ep@dfd00000 {
      compatible = "snps,dw-pcie-ep";
      reg = <0xdfc00000 0x0001000>, /* IP registers 1 */
            <0xdfc01000 0x0001000>, /* IP registers 2 */
            <0xd0000000 0x2000000>; /* Configuration space */
      reg-names = "dbi", "dbi2", "addr_space";

      interrupts = <23>, <24>;
      interrupt-names = "dma0", "dma1";

      clocks = <&sys_clk 12>, <&sys_clk 24>;
      clock-names = "dbi", "ref";

      resets = <&sys_rst 12>, <&sys_rst 24>;
      reset-names = "dbi", "phy";

      phys = <&pcie_phy0>, <&pcie_phy1>, <&pcie_phy2>, <&pcie_phy3>;
      phy-names = "pcie0", "pcie1", "pcie2", "pcie3";

      max-link-speed = <3>;
      max-functions = /bits/ 8 <4>;
    };