POSIX / libc
clock_gettime, nanosleep
Soft RTC
timekeeping baseline
Device Drivers
input timestamp, vDSO, PIC
Clock Time Subsystem
Core API
register, default source/event
counter ↔ ns conversion
Clock Source Device
get_freq / get_counter
monotonic time base
Clock Event Device
set_timeout / event ISR
timeout programming
Clock HRTimer
priority queue of timeouts
callback dispatch
Boottime Helpers
get_us / get_ns / get_s
timeval / timespec
Clock Timer Adapter
rt_clock_timer device API
unified timer interface
BSP Drivers
arch counters, clock_timer drivers, DM/OFW integration
Hardware Counter / Timer
CPU timer, SoC timer peripherals