[PATCH 2/3] dt-bindings: irqchip: imx mu work as msi controller

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

imx mu support generate irq by write a register.
provide msi controller support so other driver
can use it by standard msi interface.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 .../interrupt-controller/fsl,mu-msi.yaml      | 94 +++++++++++++++++++
 1 file changed, 94 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/interrupt-controller/fsl,mu-msi.yaml

diff --git a/Documentation/devicetree/bindings/interrupt-controller/fsl,mu-msi.yaml b/Documentation/devicetree/bindings/interrupt-controller/fsl,mu-msi.yaml
new file mode 100644
index 0000000000000..b4ac583f60227
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/fsl,mu-msi.yaml
@@ -0,0 +1,94 @@
+# 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: NXP i.MX Messaging Unit (MU)
+
+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 to signal the other processor 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-facing, Processor B-facing).
+
+  MU can work as msi interrupt controller to do doorbell
+
+properties:
+  compatible:
+    oneOf:
+      - const: fsl,imx6sx-mu-msi
+      - const: fsl,imx7ulp-mu-msi
+      - const: fsl,imx8ulp-mu-msi
+      - const: fsl,imx8-mu-msi
+      - const: fsl,imx8ulp-mu-msi-s4
+      - items:
+          - const: fsl,imx8ulp-mu-msi
+      - items:
+          - enum:
+              - fsl,imx7s-mu-msi
+              - fsl,imx8mq-mu-msi
+              - fsl,imx8mm-mu-msi
+              - fsl,imx8mn-mu-msi
+              - fsl,imx8mp-mu-msi
+              - fsl,imx8qm-mu-msi
+              - fsl,imx8qxp-mu-msi
+          - const: fsl,imx6sx-mu-msi
+      - description: MU work as msi controller
+        items:
+          - enum:
+              - fsl,imx8qm-mu-msi
+              - fsl,imx8qxp-mu-msi
+          - const: fsl,imx6sx-mu-msi
+  reg:
+    maxItems: 2
+
+  interrupts:
+    minItems: 1
+    maxItems: 2
+
+  interrupt-names:
+    minItems: 1
+    items:
+      - const: tx
+      - const: rx
+
+  clocks:
+    maxItems: 1
+
+  power-domains:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - msi-controller
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    lsio_mu12: msi@5d270000 {
+               compatible = "fsl,imx6sx-mu-msi-db";
+               msi-controller;
+               interrupt-controller;
+               reg = <0x5d270000 0x10000>,     /* A side */
+                     <0x5d300000 0x10000>;     /* B side */
+               reg-names = "a", "b";
+               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 = "a", "b";
+    };
-- 
2.35.1