Documentation/devicetree/bindings/interrupt-controller/fsl,mu-msi.yaml

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/interrupt-controller/fsl,mu-msi.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Freescale/NXP i.MX Messaging Unit (MU) work as msi controller

maintainers:
  - Frank Li <Frank.Li@nxp.com>

description: |
  The Messaging Unit module enables two processors within the SoC to
  communicate and coordinate by passing messages (e.g. data, status
  and control) through the MU interface. The MU also provides the ability
  for one processor (A side) to signal the other processor (B side) using
  interrupts.

  Because the MU manages the messaging between processors, the MU uses
  different clocks (from each side of the different peripheral buses).
  Therefore, the MU must synchronize the accesses from one side to the
  other. The MU accomplishes synchronization using two sets of matching
  registers (Processor A-side, Processor B-side).

  MU can work as msi interrupt controller to do doorbell

allOf:
  - $ref: /schemas/interrupt-controller/msi-controller.yaml#

properties:
  compatible:
    enum:
      - fsl,imx6sx-mu-msi
      - fsl,imx7ulp-mu-msi
      - fsl,imx8ulp-mu-msi
      - fsl,imx8ulp-mu-msi-s4

  reg:
    items:
      - description: a side register base address
      - description: b side register base address

  reg-names:
    items:
      - const: processor-a-side
      - const: processor-b-side

  interrupts:
    description: a side interrupt number.
    maxItems: 1

  clocks:
    maxItems: 1

  power-domains:
    items:
      - description: a side power domain
      - description: b side power domain

  power-domain-names:
    items:
      - const: processor-a-side
      - const: processor-b-side

  interrupt-controller: true

  msi-controller: true

  "#msi-cells":
    const: 0

required:
  - compatible
  - reg
  - interrupts
  - interrupt-controller
  - msi-controller
  - "#msi-cells"

additionalProperties: false

examples:
  - |
    #include <dt-bindings/interrupt-controller/arm-gic.h>
    #include <dt-bindings/firmware/imx/rsrc.h>

    msi-controller@5d270000 {
        compatible = "fsl,imx6sx-mu-msi";
        msi-controller;
        #msi-cells = <0>;
        interrupt-controller;
        reg = <0x5d270000 0x10000>,     /* A side */
              <0x5d300000 0x10000>;     /* B side */
        reg-names = "processor-a-side", "processor-b-side";
        interrupts = <GIC_SPI 191 IRQ_TYPE_LEVEL_HIGH>;
        power-domains = <&pd IMX_SC_R_MU_12A>,
                        <&pd IMX_SC_R_MU_12B>;
        power-domain-names = "processor-a-side", "processor-b-side";
    };