[PATCH v4 3/6] dt-bindings: arm: Add MPAM MSC binding

[Yin Li]

From: Rob Herring <robh@xxxxxxxxxx>

The binding is designed around the assumption that an MSC will be a
sub-block of something else such as a memory controller or cache
controller.

A key part of MPAM is we need to know about all of the MSCs in the system
before it can be enabled. This drives the need for the genericish
'arm,mpam-msc' compatible. Though we can't assume an MSC is accessible
until a h/w specific driver potentially enables the h/w.

This binding covers only the properties currently used in practice; it
can be extended as additional features are needed.

Cc: James Morse <james.morse@xxxxxxx>
Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: James Morse <james.morse@xxxxxxx>
[ Yin Li and Huang Yiwei: fix schema field order and yamllint spacing;
  fix example reg addresses; reduce to minimal binding covering only
  properties in current use, dropping RIS child nodes, memory controller
  support, arm,mpam-device, cpus and interrupt-names ]
Co-developed-by: Huang Yiwei <huang.yiwei@xxxxxxxxxxxxxxxx>
Signed-off-by: Huang Yiwei <huang.yiwei@xxxxxxxxxxxxxxxx>
Signed-off-by: Yin Li <yin.li@xxxxxxxxxxxxxxxx>
---
 .../devicetree/bindings/arm/arm,mpam-msc.yaml      | 52 ++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/arm,mpam-msc.yaml b/Documentation/devicetree/bindings/arm/arm,mpam-msc.yaml
new file mode 100644
index 000000000000..523978900d3d
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/arm,mpam-msc.yaml
@@ -0,0 +1,52 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/arm,mpam-msc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Arm Memory System Resource Partitioning and Monitoring (MPAM)
+
+maintainers:
+  - Rob Herring <robh@xxxxxxxxxx>
+
+description: |
+  The Arm MPAM specification can be found here:
+
+  https://developer.arm.com/documentation/ddi0598/latest
+
+properties:
+  compatible:
+    const: arm,mpam-msc
+
+  reg:
+    maxItems: 1
+    description: A memory region containing registers as defined in the MPAM
+      specification.
+
+  arm,not-ready-us:
+    description: The maximum time in microseconds for monitoring data to be
+      accurate after a settings change. For more information, see the
+      Not-Ready (NRDY) bit description in the MPAM specification.
+
+additionalProperties: false
+
+examples:
+  - |
+    L3: cache-controller@30000000 {
+        compatible = "foo,a-l3-cache", "cache";
+        cache-level = <3>;
+        cache-unified;
+        reg = <0x0 0x30000000 0x0 0x2000>;
+        ranges = <0x0 0x30000000 0x2000>;
+        #address-cells = <1>;
+        #size-cells = <1>;
+
+        msc@0 {
+            compatible = "arm,mpam-msc";
+            reg = <0x0 0x2000>;
+            arm,not-ready-us = <1>;
+            /* CPU affinity implied by parent cache node  */
+        };
+    };
+
+...

-- 
2.34.1