The clock tick rate was off by a factor of two in some configurations.
Use the maximum counter frequency to get the best time resolution. Do
not use the automatic interrupt clear feature.
Update #4982.
Pass the parameter of the clock interrupt handler to
Clock_driver_support_at_tick() and Clock_driver_timecounter_tick(). This makes
it possible to use the interrupt handler argument in clock drivers.
Use the interrupt handler provided by Clock_driver_support_install_isr() to
avoid local delarations of Clock_isr().
Update #4862.
Change license to BSD-2-Clause according to file history and contributor
agreements. Add Doxygen file comments.
Update #3053.
Update #3707.
Update #4982.
The aim of this clock driver hook was to stop clock tick interrupts at
some late point in the exit() procedure.
The use of atexit() pulls in malloc() which pulls in errno. It is
incompatible with the intention of the
CONFIGURE_DISABLE_NEWLIB_REENTRANCY configuration option.
The exit() function must be called from thread context, so accompanied
clock tick interrupts should cause no harm. On the contrary, someone
may assume a normal operating system operation, e.g. working timeouts.
Remove the Clock_driver_support_shutdown_hardware() clock driver hook.
Close#3436.
