[PATCH v5 1/7] dt-bindings: arm: coresight-tmc: Add "memory-region" property

From: Linu Cherian
Date: Fri Nov 10 2023 - 13:27:54 EST


memory-region 0: Reserved trace buffer memory

TMC ETR: When available, use this reserved memory region for
trace data capture. Same region is used for trace data
retention after a panic or watchdog reset.

TMC ETF: When available, use this reserved memory region for
trace data retention synced from internal SRAM after a panic or
watchdog reset.

memory-region 1: Reserved meta data memory

TMC ETR, ETF: When available, use this memory for register
snapshot retention synced from hardware registers after a panic
or watchdog reset.

Signed-off-by: Linu Cherian <lcherian@xxxxxxxxxxx>
---
Changelog from v4:
* Description is more explicit on the usage of reserved trace buffer
regions
* Removed "mem" suffix from the memory region names

.../bindings/arm/arm,coresight-tmc.yaml | 25 +++++++++++++++++++
1 file changed, 25 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/arm,coresight-tmc.yaml b/Documentation/devicetree/bindings/arm/arm,coresight-tmc.yaml
index cb8dceaca70e..6d266ac0016b 100644
--- a/Documentation/devicetree/bindings/arm/arm,coresight-tmc.yaml
+++ b/Documentation/devicetree/bindings/arm/arm,coresight-tmc.yaml
@@ -101,6 +101,28 @@ properties:
and ETF configurations.
$ref: /schemas/graph.yaml#/properties/port

+ memory-region:
+ items:
+ - description: Reserved trace buffer memory for ETR and ETF sinks.
+ For ETR, this reserved memory region is used for trace data capture.
+ Same region is used for trace data retention as well after a panic
+ or watchdog reset.
+ This reserved memory region is used as trace buffer or used for trace
+ data retention only if specifically selected by the user in sysfs
+ interface.
+ The default memory usage models for ETR in sysfs/perf modes are
+ otherwise unaltered.
+
+ For ETF, this reserved memory region is used by default for
+ retention of trace data synced from internal SRAM after a panic
+ or watchdog reset.
+ - description: Reserved meta data memory. Used for ETR and ETF sinks
+ for storing metadata.
+ memory-region-names:
+ items:
+ - const: tracedata
+ - const: metadata
+
required:
- compatible
- reg
@@ -115,6 +137,9 @@ examples:
etr@20070000 {
compatible = "arm,coresight-tmc", "arm,primecell";
reg = <0x20070000 0x1000>;
+ memory-region = <&etr_trace_mem_reserved>,
+ <&etr_mdata_mem_reserved>;
+ memory-region-names = "tracedata", "metadata";

clocks = <&oscclk6a>;
clock-names = "apb_pclk";
--
2.34.1