[PATCH v3 1/3] dt-bindings: remoteproc: k3-m4f: Add bindings for K3 AM64x SoCs

[Martyn Welch <martyn.welch@collabora.com>]

From: Hari Nagalla <hnagalla@ti.com>

K3 AM64x SoC has a Cortex M4F subsystem in the MCU voltage domain.
The remote processor's life cycle management and IPC mechanisms are
similar across the R5F and M4F cores from remote processor driver
point of view. However, there are subtle differences in image loading
and starting the M4F subsystems.

The YAML binding document provides the various node properties to be
configured by the consumers of the M4F subsystem.

Signed-off-by: Hari Nagalla <hnagalla@ti.com>
[Martyn Welch: Amended as per review comments and to pass DT tests]
Signed-off-by: Martyn Welch <martyn.welch@collabora.com>
---

Changes since v1:
 - Spelling corrections
 - Corrected to pass DT checks

Changes since v2:
 - Missed spelling correction to commit message

Note: The only review comment that I don't see directly addressed is the
      lack of description of `ti,sci`, `ti,sci-dev-id` and
      `ti,sci-proc-ids`. A reference has been added to
      `/schemas/arm/keystone/ti,k3-sci-common.yaml#` where they are
      described. I believe this is the correct approach, please advise if
      that is not the case.

 .../bindings/remoteproc/ti,k3-m4f-rproc.yaml  | 158 ++++++++++++++++++
 1 file changed, 158 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/remoteproc/ti,k3-m4f-rproc.yaml

diff --git a/Documentation/devicetree/bindings/remoteproc/ti,k3-m4f-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/ti,k3-m4f-rproc.yaml
new file mode 100644
index 000000000000..1b38df0be2e6
--- /dev/null
+++ b/Documentation/devicetree/bindings/remoteproc/ti,k3-m4f-rproc.yaml
@@ -0,0 +1,158 @@
+# SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/remoteproc/ti,k3-m4f-rproc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: TI K3 M4F processor subsystems
+
+maintainers:
+  - Hari Nagalla <hnagalla@ti.com>
+
+description: |
+  Some K3 family SoCs have Arm Cortex M4F cores. AM64x is a SoC in K3
+  family with a M4F core. Typically safety oriented applications may use
+  the M4F core in isolation without an IPC. Where as some industrial and
+  home automation applications, may use the M4F core as a remote processor
+  with IPC communications.
+
+$ref: /schemas/arm/keystone/ti,k3-sci-common.yaml#
+
+properties:
+  $nodename:
+    pattern: "^m4fss(@.*)?"
+
+  compatible:
+    enum:
+      - ti,am64-m4fss
+
+  power-domains:
+    description: |
+      Should contain a phandle to a PM domain provider node and an args
+      specifier containing the M4FSS device id value.
+    maxItems: 1
+
+  "#address-cells":
+    const: 2
+
+  "#size-cells":
+    const: 2
+
+  reg:
+    items:
+      - description: Address and Size of the IRAM internal memory region
+      - description: Address and Size of the DRAM internal memory region
+
+  reg-names:
+    items:
+      - const: iram
+      - const: dram
+
+  resets:
+    description: |
+      Should contain the phandle to the reset controller node managing the
+      local resets for this device, and a reset specifier.
+    maxItems: 1
+
+  firmware-name:
+    description: |
+      Should contain the name of the default firmware image
+      file located on the firmware search path
+
+  mboxes:
+    description: |
+      OMAP Mailbox specifier denoting the sub-mailbox, to be used for
+      communication with the remote processor. This property should match
+      with the sub-mailbox node used in the firmware image.
+    maxItems: 1
+
+  memory-region:
+    description: |
+      phandle to the reserved memory nodes to be associated with the
+      remoteproc device. There should be at least two reserved memory nodes
+      defined. The reserved memory nodes should be carveout nodes, and
+      should be defined with a "no-map" property as per the bindings in
+      Documentation/devicetree/bindings/reserved-memory/reserved-memory.yaml
+    minItems: 2
+    maxItems: 8
+    items:
+      - description: region used for dynamic DMA allocations like vrings and
+                     vring buffers
+      - description: region reserved for firmware image sections
+    additionalItems: true
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - ti,sci
+  - ti,sci-dev-id
+  - ti,sci-proc-ids
+  - resets
+  - firmware-name
+  - mboxes
+  - memory-region
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    reserved-memory {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        mcu_m4fss_dma_memory_region: m4f-dma-memory@9cb00000 {
+            compatible = "shared-dma-pool";
+            reg = <0x00 0x9cb00000 0x00 0x100000>;
+            no-map;
+        };
+
+        mcu_m4fss_memory_region: m4f-memory@9cc00000 {
+            compatible = "shared-dma-pool";
+            reg = <0x00 0x9cc00000 0x00 0xe00000>;
+            no-map;
+        };
+    };
+
+    soc {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        mailbox0_cluster0: mailbox-0 {
+            #mbox-cells = <1>;
+
+            mbox_m4_0: mbox-m4-0 {
+                ti,mbox-rx = <0 0 0>;
+                ti,mbox-tx = <1 0 0>;
+            };
+        };
+
+        bus@f0000 {
+            compatible = "simple-bus";
+            #address-cells = <2>;
+            #size-cells = <2>;
+            ranges = <0x00 0x04000000 0x00 0x04000000 0x00 0x01ff1400>;
+
+            bus@4000000 {
+                compatible = "simple-bus";
+                #address-cells = <2>;
+                #size-cells = <2>;
+                ranges = <0x00 0x04000000 0x00 0x04000000 0x00 0x01ff1400>;
+
+                mcu_m4fss: m4fss@5000000 {
+                    compatible = "ti,am64-m4fss";
+                    reg = <0x00 0x5000000 0x00 0x30000>,
+                          <0x00 0x5040000 0x00 0x10000>;
+                    reg-names = "iram", "dram";
+                    ti,sci = <&dmsc>;
+                    ti,sci-dev-id = <9>;
+                    ti,sci-proc-ids = <0x18 0xff>;
+                    resets = <&k3_reset 9 1>;
+                    firmware-name = "am62-mcu-m4f0_0-fw";
+                    mboxes = <&mailbox0_cluster0 &mbox_m4_0>;
+                    memory-region = <&mcu_m4fss_dma_memory_region>,
+                                    <&mcu_m4fss_memory_region>;
+                };
+            };
+        };
+    };
-- 
2.39.1