[SL-ONLY] [Cherry-Pick] Tracing: Energy state stats (#699)

[malbert-silabs]

Cherry Pick #699

This is a cherry pick of #699 for release 2.8. The rest of the description body is from the original PR

Summary

This PR add two new features.

1. An optional addition to the existing tracing infrastructure to see quick statistics about the energy states

2. An optional addition to record and output all energy state transition traces for analysis with other tools.

WIP Confluence page: https://confluence.silabs.com/spaces/MATTER/pages/745094873/Energy+Mode+Tracing+and+Statistics

Related issues

Closes: https://jira.silabs.com/browse/MATTER-5331
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Testing

Added unit tests for the energy tracing feature. Uses stubs for PowerManager and CMSIS.

Tested feature on LIT-ICD app and Lighting app on series 2 and 3.
Tested on UART and RTT for the transition traces.

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Note

Adds optional energy mode statistics and transition tracing on Silabs, wired via GN args, exposed via tracing energy CLI, initialized behind flags, and covered by unit tests; also drops totalTaskCount from FreeRTOS stats.

• Silabs Tracing:
  • Energy Mode Stats: Track and report time/percentage/longest/transition-count per energy mode in SilabsTracing (OutputPowerManagerStatistics), enabled by SL_TRACING_ENERGY_STATS and accessible via tracing energy.
  • Energy Transition Traces: New SilabsPowerTracing component to record EM transitions over time and log them after a timer; initialized in MatterConfig.cpp when SL_TRACING_ENERGY_TRACES==1.
  • Build/Config: New GN args in src/platform/silabs/tracing/args.gni; config header defines (SL_TRACING_ENERGY_STATS, SL_TRACING_ENERGY_TRACES, periods/max); new SilabsPowerTracing target and deps; EFR32 BUILD.gn wires in tracing libs and tests.
  • Shell: Adds tracing energy command to print energy mode statistics.
  • Timing: Introduces SL_GET_SLEEPTIMER_TIME for EM2-safe timestamps.
• FreeRTOS Task Stats:
  • Removes totalTaskCount from SystemTaskStats and associated log output.
• Tests:
  • Adds unit tests for energy tracing with CMSIS/Power Manager stubs and integrates into silabs_platform_tests.

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[Copilot]

Pull Request Overview

This PR adds energy state tracing capabilities to the Silicon Labs platform, enabling developers to monitor device energy mode transitions and statistics. The implementation includes two optional features: real-time energy state statistics accessible via the "tracing energy" CLI command, and detailed transition traces for external analysis.

• New SilabsPowerTracing class for recording energy mode transitions with timestamp tracking
• Statistics collection for time spent in each energy mode (EM0-EM2) with percentage calculations
• Unit tests with stub implementations for PowerManager and CMSIS OS2 APIs

Reviewed Changes

Copilot reviewed 19 out of 19 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/platform/silabs/tracing/tests/mocks/sl_power_manager_stub.h	Stub header defining PowerManager types and functions for unit tests
src/platform/silabs/tracing/tests/mocks/sl_power_manager_stub.cpp	No-op stub implementations of PowerManager functions
src/platform/silabs/tracing/tests/mocks/cmsis_os2_stub.h	Stub header defining CMSIS-OS2 timer types and functions for unit tests
src/platform/silabs/tracing/tests/mocks/cmsis_os2_stub.cpp	Minimal stub implementations returning success/dummy values
src/platform/silabs/tracing/tests/TestSilabsPowerTracing.cpp	Unit tests covering basic functionality, buffer overflow handling, and initialization failures
src/platform/silabs/tracing/tests/BUILD.gn	Build configuration for tracing unit tests
src/platform/silabs/tracing/args.gni	Build arguments for enabling energy stats and traces features
src/platform/silabs/tracing/SilabsTracingMacros.h	Macro for obtaining sleeptimer-based timestamps
src/platform/silabs/tracing/SilabsTracing.h	Extended tracer with PowerManager statistics tracking members and methods
src/platform/silabs/tracing/SilabsTracing.cpp	Implemented PowerManager transition callbacks and statistics output logic
src/platform/silabs/tracing/SilabsPowerTracing.h	Header defining the power tracing singleton class interface
src/platform/silabs/tracing/SilabsPowerTracing.cpp	Implementation of power tracing with trace buffer and timer management
src/platform/silabs/tracing/BUILD.gn	Build configuration adding power tracing library
src/platform/silabs/tests/BUILD.gn	Added tracing tests to platform test group
src/platform/silabs/efr32/BUILD.gn	Conditional dependency on power tracing library
examples/platform/silabs/shell/tracing/TracingShellCommands.cpp	Added "energy" CLI command handler
examples/platform/silabs/MatterConfig.cpp	Initialize power tracing singleton during Matter setup
examples/platform/silabs/FreeRTOSRuntimeStats.h	Removed unused totalTaskCount field from SystemTaskStats
examples/platform/silabs/FreeRTOSRuntimeStats.c	Removed calculation of unused totalTaskCount field

Comments suppressed due to low confidence (2)

src/platform/silabs/tracing/SilabsTracing.cpp:836

• The removal of totalTaskCount from the log output appears unrelated to energy tracing functionality. This change modifies task statistics logging behavior and should either be documented in the PR description or moved to a separate commit, as it's not part of the energy state tracing feature being added.

    ChipLogProgress(DeviceLayer, "Active tasks: %lu | Terminated tasks: %lu", systemStats.activeTaskCount,
                    systemStats.terminatedTaskCount);

examples/platform/silabs/FreeRTOSRuntimeStats.h:1

• The removal of totalTaskCount from SystemTaskStats is unrelated to energy tracing and could break existing code that depends on this field. This change should be in a separate PR or clearly documented as a related cleanup with justification for why it's being removed.

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