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>
Directly use the Kconfig defined CONFIG_CLOCK_FREQ in the code and
avoid defining F_CPU. Also, remove the unnecessary O2 option - that
is already the default from the main makefile.
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>
Provide hand-coded assembler for timer_is_before() on AVR as that code
is used frequently in the time-critical timer dispatch loop and gcc
doesn't do a good job at compiling that comparison code. Remove the
no longer needed waketime+1 hack from reschedule_timer().
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 hardware timer overflow bit can be used to optimize the conversion
from 16bit timers to 32bit timers.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
There is a small possibility that a shutdown could occur between
clearing transmit_max and clearing transmit_pos - so make sure to
handle the case where transmit_pos > transmit_max.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
As long as the code is careful when writing the in_sendf variable it
should be safe to update it without having to disable irqs.
Also, make sure in_sendf is cleared on shutdown.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Don't assume the hardware ADC has 10bit resultion - instead have the
firmware define a constant and read that constant in the host.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Add a DECL_CONSTANT macro to allow the firmware to define constants
that are to be exported to the host during the "identify" phase. This
replaces the existing hardcoded mechanism of scanning the Kconfig
header file for certain constants.
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>
Rework the timer prioritization code so that is compares against the
current time instead of the number of repeat timers in a given
interrupt. This makes the code slightly faster and it should provide
better protection against task starvation.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Increase the size of the serial receive buffer. With transmit rates
of 250000 baud, it only takes a little over a millisecond to overflow
the existing buffer.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
On faster MCUs the step and unstep events may be too close for the
stepper motor driver. Add a CONFIG_NO_UNSTEP_DELAY build option and
support the case where it is not set. This allows faster MCUs to
schedule two events for each step (one for the step and one for the
unstep).
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Introduce enable_tx_irq() for manipulating the AVR hardware. This
keeps the low-level hardware code together.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Default to O2 and set Os in the AVR makefile. Platforms besides AVR
are likely to produce better code with O2 so make that the default.
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>
Some boards may not support hardware based PWM. Update the build so
that those commands do not need to be compiled if they are not
available.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Some boards may not support SPI transfers. Update the build so that
those commands do not need to be compiled if they are not available.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Some boards may not support the ADC hardware. Update the build so
that those commands do not need to be compiled if they are not
available.
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>
Some AVR chips ship with a 1/8th clock divisor set. Add a compile
time option to manually clear this field at startup.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
The gpio_adc_info only contains a single uint8_t field - it's simpler
to use an array of uint8_t instead.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Kevin O'Connor