Allow timer_dispatch_many() to run for extended periods if there are
no tasks pending. This reduces the amount of lost cpu time spent
entering and exiting the irq handler.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Track when tasks are pending and spin in irq_wait() when no tasks are
pending. This improves the mechanism for sleeping the processor -
it's simpler for the board specific code and it reduces the
possibility of the processor sleeping when tasks are busy.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Don't rely on the generic scheduler code to always have a timer no
more than 1ms in the future. Instead, create an avr specific timer
that will be called every 0x8000 ticks. This simplifies the generic
code and it reduces the amount of code that needs to be run every
millisecond.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
If sched_add_timer() is called on a timer that would make it the new
head of the list, then add it and signal the board code that the timer
should be rescheduled.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Implement new dynmem_start() and dynmem_end() functions instead of
alloc_chunk() and alloc_chunks() in the board code. This simplifies
the board code.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Export a new console_sendf() function from the board code instead of
console_get_output() and console_push_output(). This enables more
flexibility in how the board specific code produces output.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Move the command_task() code from the generic code to the board
specific code. This enables more flexibility in how the board
specific code processes input.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Avoid using linker magic to define the init, task, and shutdown
functions. Instead, use the compile_time_request system. This
simplifies the build and produces more efficient code.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Introduce a new board function alloc_chunk() to allocate dynamic
memory. This allows the board code to implement memory allocations
without using the standard malloc() interface.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Rename the file to make it clear that the code is helper functions for
boards with irq based timers.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Rename sched_timer_kick() to sched_timer_dispatch() and move its loop
into its callers in the board code. This eliminates the need to
export timer_try_set_next() from the board code.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Reset the timer repeat checks on shutdown, otherwise it is possible to
get into an infinite shutdown loop.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Explicilty load the timer waketime variable into local variables in
sched_timer_kick(). Change the optimization level from Os to O2.
This helps gcc to avoid unnecessary reloads from memory in the common
stepper_event() case.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Move sched_is_before() from sched.c to timer_is_before() in the board
specific timer code. This allows the board code to provide its own
definition.
Also, remove the sched_from_us() and sched_read_time() wrapper
functions and change the callers to directly invoke timer_from_us() /
timer_read_time().
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Most of sam3x8e/timer.c is going to be platform agnostic for any board
with standard irq handling. Move the generic code into a new file
generic/timer.c.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
It's tricky to reschedule the timer irq correctly (due to race
conditions with the irq) and in practice it's very rarely needed.
Handle the special cases in the generic sched.c code so that the board
code doesn't have to handle it.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
The irq handling in sam3x8e isn't specific to the sam3x8e proccessor -
it's generic for all armcm type machines. So, move the definitions
into a new file generic/armcm-irq.c
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Return the number of clock ticks to wait directly from
gpio_adc_sample(). This simplifies the ADC interface.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
The AVR wants a uint8_t return type for irq_save(), but other
architectures will generally prefer int. Allow the board to configure
the size of the flag by introducing an irqstatus_t typedef.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Move the definitions of the readb() style functions to a new header
generic/io.h. This eliminates the dependency of stdint.h on
compiler.h.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Instead of creating a misc.h file in each board directory, create a
generic board directory and declare misc.h there.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Kevin O'Connor