[PATCH] dt-bindings: sram: Tightly Coupled Memory (TCM) bindings

* [PATCH] dt-bindings: sram: Tightly Coupled Memory (TCM) bindings
@ 2023-01-13  7:30 Tanmay Shah
  2023-01-13  7:52 ` Krzysztof Kozlowski
                   ` (2 more replies)
  0 siblings, 3 replies; 13+ messages in thread
From: Tanmay Shah @ 2023-01-13  7:30 UTC (permalink / raw)
  To: robh+dt, krzysztof.kozlowski+dt
  Cc: devicetree, linux-kernel, linux-remoteproc, tanmay.shah

This patch introduces bindings for TCM memory address space on AMD-xilinx
platforms. As of now TCM addresses are hardcoded in xilinx remoteproc
driver. This bindings will help in defining TCM in device-tree and
make it's access platform agnostic and data-driven from the driver.

Signed-off-by: Tanmay Shah <tanmay.shah@amd.com>
---
 .../devicetree/bindings/sram/xlnx,tcm.yaml    | 137 ++++++++++++++++++
 1 file changed, 137 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/sram/xlnx,tcm.yaml

diff --git a/Documentation/devicetree/bindings/sram/xlnx,tcm.yaml b/Documentation/devicetree/bindings/sram/xlnx,tcm.yaml
new file mode 100644
index 000000000000..02d17026fb1f
--- /dev/null
+++ b/Documentation/devicetree/bindings/sram/xlnx,tcm.yaml
@@ -0,0 +1,137 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sram/xlnx,tcm.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Tightly Coupled Memory (TCM)
+
+maintainers:
+  - Tanmay Shah <tanmay.shah@amd.com>
+
+description: |
+  Tightly Coupled Memory(TCM) is available on AMD-Xilinx paltforms for ARM
+  cortex remote processors to use. It is low-latency memory that provide
+  predictable instruction execution and predictable data load/store timing.
+  TCM can be configured in lockstep mode or split mode. In split mode
+  configuration each RPU core has its own set of ATCM and BTCM memories and in
+  lockstep mode redundant processor's TCM become available to lockstep
+  processor. So In lockstep mode ATCM and BTCM size is increased.
+
+properties:
+  $nodename:
+    pattern: "sram-[0-9a-f]+$"
+
+patternProperties:
+  "^tcm-[a-z]+@[0-9a-f]+$":
+    type: object
+    description: |
+      During the split mode, each RPU core has its own set of ATCM and BTCM memory
+
+      During the lock-step operation, the TCMs that are associated with the
+      redundant processor become available to the lock-step processor.
+      For example if each individual processor has 64KB ATCM, then in lockstep mode
+      The size of ATCM become 128KB. Same for BTCM. tcm-lockstep node represents
+      TCM address space in lockstep mode. tcm-core@x node specfies each core's
+      TCM address space in split mode.
+
+    properties:
+      compatible:
+        oneOf:
+          - items:
+              - enum:
+                  - xlnx,tcm-lockstep
+                  - xlnx,tcm-split
+
+      "#address-cells":
+        const: 1
+
+      "#size-cells":
+        const: 1
+
+      reg:
+        items:
+          - description: |
+              ATCM Memory address space. An ATCM typically holds interrupt or
+              exception code that must be accessed at high speed, without any
+              potential delay resulting from a cache miss.
+              RPU on AMD-Xilinx platform can also fetch data from ATCM
+          - description: |
+              BTCM Memory address space. A BTCM typically holds a block of data
+              for intensive processing, such as audio or video processing. RPU on
+              AMD-Xilinx Platforms can also fetch Code (Instructions) from BTCM
+
+      reg-names:
+        items:
+          - const: atcm
+          - const: btcm
+
+      ranges: true
+
+      power-domains:
+        maxItems: 8
+        items:
+          - description: list of ATCM Power domains
+          - description: list of BTCM Power domains
+        additionalItems: true
+
+    required:
+      - compatible
+      - '#address-cells'
+      - '#size-cells'
+      - reg
+      - ranges
+      - power-domains
+    unevaluatedProperties: false
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/power/xlnx-zynqmp-power.h>
+
+    amba {
+        sram@ffe00000 {
+            tcm-lockstep@ffe00000 {
+                compatible = "xlnx,tcm-lockstep";
+
+                #address-cells = <1>;
+                #size-cells = <1>;
+
+                reg = <0xffe00000 0x20000>, <0xffe20000 0x20000>;
+                reg-names = "atcm", "btcm";
+                ranges = <0x0 0xffe00000 0x20000>, <0x20000 0xffe20000 0x20000>;
+                power-domains = <&zynqmp_firmware PD_R5_0_ATCM>,
+                                <&zynqmp_firmware PD_R5_1_ATCM>,
+                                <&zynqmp_firmware PD_R5_0_BTCM>,
+                                <&zynqmp_firmware PD_R5_1_BTCM>;
+            };
+
+            tcm-core@0 {
+                compatible = "xlnx,tcm-split";
+
+                #address-cells = <1>;
+                #size-cells = <1>;
+
+                reg = <0xffe00000 0x10000>, <0xffe20000 0x10000>;
+                reg-names = "atcm", "btcm";
+                ranges = <0x0 0xffe00000 0x10000>, <0x20000 0xffe20000 0x10000>;
+                power-domains = <&zynqmp_firmware PD_R5_0_ATCM>,
+                                <&zynqmp_firmware PD_R5_0_BTCM>;
+            };
+
+            tcm-core@1 {
+                compatible = "xlnx,tcm-split";
+
+                #address-cells = <1>;
+                #size-cells = <1>;
+
+                reg = <0xffe90000 0x10000>, <0xffeb0000 0x10000>;
+                reg-names = "atcm", "btcm";
+                ranges = <0x0 0xffe90000 0x10000>, <0x20000 0xffeb0000 0x10000>;
+                power-domains = <&zynqmp_firmware PD_R5_1_ATCM>,
+                                <&zynqmp_firmware PD_R5_1_BTCM>;
+            };
+        };
+    };
+...

base-commit: 6b31ffe9c8b9947d6d3552d6e10752fd96d0f80f
-- 
2.25.1


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