PTPd Service Enhancement: Supports Ethernet Synchronization / Logic Optimization / Alignment with Linux PTPv4 Options

[Donny9]

Summary

This patch series brings comprehensive PTP (Precision Time Protocol) daemon support to NuttX, implementing a complete IEEE 1588 PTPv2 stack with the following key enhancements:

1. Core Infrastructure (dc94b2418a, 32ef6dc612):

   • Added CMake build system support for ptpd
   • Fixed structure byte alignment for cross-core communication compatibility

2. Debug and Logging (5aecb30da3):

   • Migrated from custom NETUTILS_PTPD_DEBUG to standard DEBUG_PTP_* macros
   • Integrated with NuttX PTP clock device debug framework

3. Task Management Redesign (e2737dd6f1, 09420b3f46):

   • Replaced separate task creation with main task execution model
   • Unified command interface: ptpd -i eth0 & for start, ptpd -d pid for stop
   • Introduced struct ptpd_config_s for dynamic configuration
   • Enables background execution with proper lifecycle management

4. Hardware Timestamping Support (0985006e26, d5713d2494):

   • Runtime-configurable hardware timestamp via hardware_ts flag
   • Replaced CONFIG_NET_TIMESTAMP with dynamic configuration
   • Enhanced precision using SO_TIMESTAMPNS for nanosecond timestamps

5. PTP Clock Device Integration (71598b6f5d, 10b7258a14, 757744add4):

   • Added NET_PKT dependency for PTP clock device support
   • Implemented clock_adjtime() support for PTP hardware clocks via CLOCKFD
   • Added CONFIG_NETUTILS_PTPD_ADJTIME_THRESHOLD_NS for accelerated adjustment
   • Optimized time adjustment convergence speed

6. BMCA and Clock Selection (3b20797945, 3cab597f01):

   • Fixed missing comparisons in is_better_clock() for BMCA compliance
   • Added semaphore cleanup in ptpd_status() to prevent resource leaks

7. Transport Layer (ebd885e1dd, 8f8bc63769):

   • Implemented PTP Ethernet transport (Layer 2) via raw socket support
   • Added -B option to control BMCA (Best Master Clock Algorithm) messages

8. Configuration Flexibility (32b4ef4dc5):

   • Dynamic runtime configuration for client-only and delay-e2e modes
   • Removed compile-time Kconfig restrictions (PTPD_CLIENT/PTPD_SERVER)
   • Fixed compilation warnings when enabling subset configurations

9. gPTP Switch Support (f61389ed64):

   • Added path delay correction field support for gPTP-aware switches
   • Enables accurate time synchronization in switched network topologies

The series transforms ptpd from a basic proof-of-concept into a production-ready PTP daemon with hardware timestamp support, flexible transport options, and full integration with NuttX PTP clock framework.

Impact

Users:

• New command-line interface requires updating ptpd invocation scripts
• Old: ptpd start eth0 &, New: ptpd -i eth0 &
• Background execution now mandatory using '&' operator
• Client-only and delay mode now configured at runtime, not compile-time

Build System:

• CMake support added alongside Make build system
• New Kconfig dependencies: requires NET_PKT when using PTP clock devices
• Removed several Kconfig options in favor of runtime configuration

Hardware Requirements:

• Hardware timestamping now supported but optional (fallback to software)
• PTP clock device (/dev/ptp*) integration requires CONFIG_PTP_CLOCK
• Network drivers should implement SO_TIMESTAMPNS for best accuracy

Configuration:

• CONFIG_NETUTILS_PTPD_ADJTIME_THRESHOLD_NS controls adjustment speed
• BMCA behavior controlled via -B command-line option
• Transport type (UDP/Ethernet) selected automatically based on capabilities

Compatibility:

• Breaking: Command-line interface changed
• Breaking: Some Kconfig options removed
• Forward: Maintains IEEE 1588-2008 PTPv2 protocol compatibility
• Enhanced: Better interoperability with gPTP switches

Documentation:

• New command syntax requires documentation updates
• PTP clock device integration needs cross-reference to driver docs

Security:

• Raw socket support (Ethernet transport) requires appropriate permissions
• No authentication mechanisms added (per IEEE 1588 standard)

Testing

ptp sync base on tricore tc4 platform: Initial synchronization error: ±50 μs, converging to ±2.5 μs within 3 seconds.