In #4683, tannewt noticed that uncrustify was not running on some
file in common-hal.
I investigated and found that it was not being run on a bunch of paths.
Rather than make incremental changes, I rewrote list_files to work
bsaed on regular expressions; these regular expressions are created from
the same git-style glob patterns.
I spot-checked some specific filenames after this change, and all looks good:
```
$ python3 tools/codeformat.py -v --dry-run tests/basics/int_small.py ports/raspberrypi/common-hal/pulseio/PulseIn.c extmod/virtpin.c tests/thread/thread_exit1.py ports/raspberrypi/background.h extmod/re1.5/recursiveloop.c
tools/codeformat.py -v --dry-run tests/basics/int_small.py ports/raspberrypi/common-hal/pulseio/PulseIn.c extmod/virtpin.c tests/thread/thread_exit1.py ports/raspberrypi/background.h extmod/re1.5/recursiveloop.c
uncrustify -c /home/jepler/src/circuitpython/tools/uncrustify.cfg -lC --no-backup extmod/virtpin.c ports/raspberrypi/background.h ports/raspberrypi/common-hal/pulseio/PulseIn.c
black --fast --line-length=99 -v tests/thread/thread_exit1.py
```
recursiveloop and int_small are excluded, while PulseIn, virtpin,
and background are included.
Testing running from a subdirectory (not _specifically_ supported though):
```
(cd ports && python3 ../tools/codeformat.py -v --dry-run raspberrypi/common-hal/pulseio/PulseIn.c ../extmod/virtpin.c)
../tools/codeformat.py -v --dry-run raspberrypi/common-hal/pulseio/PulseIn.c ../extmod/virtpin.c
uncrustify -c /home/jepler/src/circuitpython/tools/uncrustify.cfg -lC --no-backup ../extmod/virtpin.c raspberrypi/common-hal/pulseio/PulseIn.
```
As a side-effect, a bunch more files are re-formatted now. :-P
After this change, the following program works for me on the MIMXRT1010-EVK:
```python
import pwmio
import board
p = pwmio.PWMOut(board.D13, frequency=1_000_000, variable_frequency=True)
p.duty_cycle = 32868
while True:
pass
```
Querying and varying the duty_cycle and frequency work as well.
The lowest frequency obtainable is about 2kHz; there is an additional
divider which would allow lower PWM frequencies (I think 1kHz is important
for servos?)
Something odd happens with very low duty cycles, such as
```python
>>> p.frequency = 2000
>>> p.duty_cycle = 2
```
instead of a symmetrical waveform, it's asymmetrical. With `duty_cycle=4`,
the effect disappears. The reason for this is probably hidden in the
datasheet, but could affect servos or other things that count pulse
widths.
Set the betweenTransferDelay to the SCK low-time, to avoid long pauses
between bytes (transfers) while preventing the last SCK cycle in a byte
from being a runt pulse.
Compared to an earlier revision of this change, which just set the delays
all to zero, this doesn't break using an AirLift, which was sensitive
to the runt pulses (the simple loopback-wire test didn't detect the problem)
without this, the baud rate could be wrong; in my testing, it was
low by a factor of 2 when requesating baudrate=1_000_000 (1MHz).
When passing the baudrate in to LPSPI_MasterInit, the setting is made
automatically, but LPSPI_MAster_SetBaudRate just returns it via the
out-parameter tcrPrescaleValue.
This is a slight trade-off with code size, in places where a "_varg"
mp_raise variant is now used. The net savings on trinket_m0 is
just 32 bytes.
It also means that the translation will include the original English
text, and cannot be translated. These are usually names of Python
types such as int, set, or dict or special values such as "inf" or
"Nan".