Adds two board config define's, which can be added in a board's
mpconfigboard.h: BOARD_XOSC_FREQ_HZ, and BOARD_XOSC_IS_CRYSTAL, which
are passed to clock_init(). External clock sources are currently only
implemented for SAM_D5X_E5X series chips, so defining BOARD_XOSC_FREQ_HZ
for a SAMD21 board will emit an error.
Signed-off-by: Qyriad <qyriad@qyriad.me>
This allows you to initialize usb_host.Port once successfully and
then returns the same object as long as you pass the same arguments
in. It does allow you to fix incorrect pins but not switching from
one valid set to another. (It needs a reset for that.)
This also moves hcd cache operations to RAM so that they don't
access the cache when doing maintenance.
The picodvi PR #7880 switched the saved word to the watchdog
register since it reworked the RAM layout. This works for
reset_into_safe_mode because the watchdog scratch registers are
preserved by soft resets. They *aren't* preserved for pressing the
reset button. So it broken manual safe mode. Switch back to using
RAM to store the saved word but use the pico-sdks "uninitialized"
designation instead of a fixed location.
Also fixes USB host feather status neopixel by setting the power
pin.
By pausing audio during flash writes, the worst screeching of #8121
is avoided. I don't consider this a full fix, but it greatly improves
the by far most common scenario in which the problem occurs.
Tested on rp2040 prop feather with a midi synth playing arpeggios. When
writing to the flash e.g., with
```
dd bs=512 count=32 if=/dev/zero of=/media/jepler/CIRCUITPY/boop
```
the audio goes "tap tap tap tap" during the flash write instead of the
squawking.
This isn't a 100% fix; it will still glitch out, including during USB
enumeration which must be taking a long time without servicing background
tasks. Add a delay if not usb-connected at startup ameliorates this
greatly.
