Because this must be treated like an in-use pin for all other purposes,
unfortunately a special case must be added in shared-bindings.
Multiple AnalogIn objects for VOLTAGE_MONITOR can be created (because
in use tracking isn't working) but this causes no harm.
Testing performed: Read the monitor, then imported wifi. When the
pin state was insufficiently restored, the second step would fail
with debug messages about do_ioctl timeout.
```
import analogio, board
a = analogio.AnalogIn(board.VOLTAGE_MONITOR)
print(a.value)
import wifi
```
Closes: #7020
This reduces power consumption during true deep sleep.
In my measurements with ppk2 and a program that _irrevocably_ entered
deep sleep (no time alarm or pin alarm), power usage as measured on a
ppk2 decreased from ~10mA to ~1mA.
.. the value actually needs to be enforced each time the STA or AP
is enabled, because internally there's a call to cyw43_wifi_pm with the
library's defaut power management value, not ours.
Add a getter, though it only returns our idea of what the power
management register is set to, it doesn't read out from the actual
hardware, sadly.
Originally, black_bindings found each contiguous "//|" block and sent
it to black independently. This was slower than it needed to be.
Instead, swap the comment prefix: when running black, take off
"//|" prefixes and put "##|" prefixes on all un-prefixed lines.
Then, after black is run, do the opposite operation
This more than doubles the overall speed of "pre-commit run --all",
from 3m20s to 55s CPU time on my local machine (32.5s to under 10s
"elapsed" time)
It also causes a small amount of churn in the bindings, because
black now sees enough context to know whether one 'def' follows another
or ends the 'def's in a 'class'. In the latter case, it adds an extra
newline, which becomes a "//|" line.
I'm less sure why a trailing comma was omitted before down in
rp2pio/StateMachine.c but let's roll with it.
Now a 'once' and a 'loop' buffer can be specified.
'once' is useful for things like writing a neopixel strip in the background,
if you can guarantee the buffer contents are stable until the write is complete.
'loop' is useful for periodic things, like pwm & servos.
both together are useful for some special cases of pwm/servo, where a
transitional waveform needs to be played for one repetition and then
a new waveform needs to be played after that.
The API is renamed to reflect that it's a more generic 'background'
operation.
This is needed so that the floppy flux reader can enable the pull up
on the index pin while using it as a pio jmp pin.
Also fixes a doc bug where the `jmp_pin` was omitted in one spot in the docs.
