dt-bindings: interrupt-controller: Convert fsl,mpic-msi to YAML

As part of a larger effort to bring various PowerPC-related bindings
into the YAML world, this patch converts msi-pic.txt to YAML and moves
it into the bindings/interrupt-controller/ directory. The conversion may
necessarily be a bit hard to read because the binding is quite verbose.

Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
Link: https://lore.kernel.org/r/20250611-msipic-yaml-v2-1-f2e174c48802@posteo.net
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

Author: neuschaefer

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

@@ -0,0 +1,161 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/interrupt-controller/fsl,mpic-msi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Freescale MSI interrupt controller
+
+description: |
+  The Freescale hypervisor and msi-address-64
+  -------------------------------------------
+
+  Normally, PCI devices have access to all of CCSR via an ATMU mapping.  The
+  Freescale MSI driver calculates the address of MSIIR (in the MSI register
+  block) and sets that address as the MSI message address.
+
+  In a virtualized environment, the hypervisor may need to create an IOMMU
+  mapping for MSIIR.  The Freescale ePAPR hypervisor has this requirement
+  because of hardware limitations of the Peripheral Access Management Unit
+  (PAMU), which is currently the only IOMMU that the hypervisor supports.
+  The ATMU is programmed with the guest physical address, and the PAMU
+  intercepts transactions and reroutes them to the true physical address.
+
+  In the PAMU, each PCI controller is given only one primary window.  The
+  PAMU restricts DMA operations so that they can only occur within a window.
+  Because PCI devices must be able to DMA to memory, the primary window must
+  be used to cover all of the guest's memory space.
+
+  PAMU primary windows can be divided into 256 subwindows, and each
+  subwindow can have its own address mapping ("guest physical" to "true
+  physical").  However, each subwindow has to have the same alignment, which
+  means they cannot be located at just any address.  Because of these
+  restrictions, it is usually impossible to create a 4KB subwindow that
+  covers MSIIR where it's normally located.
+
+  Therefore, the hypervisor has to create a subwindow inside the same
+  primary window used for memory, but mapped to the MSIR block (where MSIIR
+  lives).  The first subwindow after the end of guest memory is used for
+  this.  The address specified in the msi-address-64 property is the PCI
+  address of MSIIR.  The hypervisor configures the PAMU to map that address to
+  the true physical address of MSIIR.
+
+maintainers:
+  - J. Neuschäfer <j.ne@posteo.net>
+
+properties:
+  compatible:
+    oneOf:
+      - enum:
+          - fsl,mpic-msi
+          - fsl,mpic-msi-v4.3
+          - fsl,ipic-msi
+          - fsl,vmpic-msi
+          - fsl,vmpic-msi-v4.3
+      - items:
+          - enum:
+              - fsl,mpc8572-msi
+              - fsl,mpc8610-msi
+              - fsl,mpc8641-msi
+          - const: fsl,mpic-msi
+
+  reg:
+    minItems: 1
+    items:
+      - description: Address and length of the shared message interrupt
+          register set
+      - description: Address of aliased MSIIR or MSIIR1 register for platforms
+          that have such an alias. If using MSIIR1, the second region must be
+          added because different MSI group has different MSIIR1 offset.
+
+  interrupts:
+    minItems: 1
+    maxItems: 16
+    description:
+      Each one of the interrupts here is one entry per 32 MSIs, and routed to
+      the host interrupt controller. The interrupts should be set as edge
+      sensitive. If msi-available-ranges is present, only the interrupts that
+      correspond to available ranges shall be present.
+
+  msi-available-ranges:
+    $ref: /schemas/types.yaml#/definitions/uint32-matrix
+    items:
+      items:
+        - description: First MSI interrupt in this range
+        - description: Number of MSI interrupts in this range
+    description:
+      Define which MSI interrupt can be used in the 256 MSI interrupts.
+      If not specified, all the MSI interrupts can be used.
+      Each available range must begin and end on a multiple of 32 (i.e. no
+      splitting an individual MSI register or the associated PIC interrupt).
+
+  msi-address-64:
+    $ref: /schemas/types.yaml#/definitions/uint64
+    description:
+      64-bit PCI address of the MSIIR register. The MSIIR register is used for
+      MSI messaging.  The address of MSIIR in PCI address space is the MSI
+      message address.
+
+      This property may be used in virtualized environments where the hypervisor
+      has created an alternate mapping for the MSIR block.  See the top-level
+      description for an explanation.
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - fsl,mpic-msi-v4.3
+              - fsl,vmpic-msi-v4.3
+    then:
+      properties:
+        interrupts:
+          minItems: 16
+          description:
+            Version 4.3 implies that there are 16 shared interrupts, and they
+            are configured through MSIIR1.
+
+        # MPIC v4.3 does not support this property because the 32 interrupts of
+        # an individual register are not continuous when using MSIIR1.
+        msi-available-ranges: false
+
+        reg:
+          minItems: 2
+
+    else:
+      properties:
+        interrupts:
+          maxItems: 8
+          description:
+            In versions before 4.3, only 8 shared interrupts are available, and
+            they are configured through MSIIR.
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    msi@41600 {
+            compatible = "fsl,mpc8610-msi", "fsl,mpic-msi";
+            reg = <0x41600 0x80>;
+            msi-available-ranges = <0 0x100>;
+            interrupts = <0xe0 0>, <0xe1 0>, <0xe2 0>, <0xe3 0>,
+                         <0xe4 0>, <0xe5 0>, <0xe6 0>, <0xe7 0>;
+    };
+
+  - |
+    msi@41600 {
+            compatible = "fsl,mpic-msi-v4.3";
+            reg = <0x41600 0x200>, <0x44148 4>;
+            interrupts = <0xe0 0 0 0>, <0xe1 0 0 0>, <0xe2 0 0 0>, <0xe3 0 0 0>,
+                         <0xe4 0 0 0>, <0xe5 0 0 0>, <0xe6 0 0 0>, <0xe7 0 0 0>,
+                         <0x100 0 0 0>, <0x101 0 0 0>, <0x102 0 0 0>, <0x103 0 0 0>,
+                         <0x104 0 0 0>, <0x105 0 0 0>, <0x106 0 0 0>, <0x107 0 0 0>;
+    };
+
+...