I recently misdiagnosed a "maybe-uninitialized" diagnostic as a bug in
asf4. However, the problem was in our SPI code.
A special case for samr21 MCUs was being applied to same54p20a and possibly
other D5x/E5x MCUs, since the check was simply for pin PC19 existing at all.
Change the check to use the macro PIN_PC19F_SERCOM4_PAD0 which is only
defined if special function F of pin PC19 is SERCOM4 PAD0.
Reorganize the code a little bit so that brace-matching in editors is
not confused by the conditionalized code, including an unrelated change
for APA102_SCK's condition.
Revert the change to the Makefile that incorrectly attempted to silence
the diagnostic.
This started while adding USB MIDI support (and descriptor support is
in this change.) When seeing that I'd have to implement the MIDI class
logic twice, once for atmel-samd and once for nrf, I decided to refactor
the USB stack so its shared across ports. This has led to a number of
changes that remove items from the ports folder and move them into
supervisor.
Furthermore, we had external SPI flash support for nrf pending so I
factored out the connection between the usb stack and the flash API as
well. This PR also includes the QSPI support for nRF.
This saves code space in builds which use link-time optimization.
The optimization drops the untranslated strings and replaces them
with a compressed_string_t struct. It can then be decompressed to
a c string.
Builds without LTO work as well but include both untranslated
strings and compressed strings.
This work could be expanded to include QSTRs and loaded strings if
a compress method is added to C. Its tracked in #531.
Its slimmed down by removing the qstr and bit packing TCC info.
The trinket m0 build actually grows by 20 bytes. The arduino zero
build shrinks by 188 bytes.
1. UART: ported to ASF4. Allow rx-only and tx-only. Add .baudrate r/w property.
2. Make NeoPixel timing deterministic by turning off caches during NeoPixel writes.
3. Incorporate asf4 updates:
a. async USART driver
b. bringing Atmel START configuration closer to what we use
c. Clock initialization order now specified by CIRCUITPY_GCLK_INIT_1ST and _LAST.
4. supervisor/port.c: Move commented-out clock-test pin setting to correct location.
all: Add .frequency read-only property for busio.SPI to return actual frequency.
Fix esp8266/posix_helpers.c, which was not up to date for the new
long-lived/short-lived heap allocation scheme.
Also, fixed pin mappings for rev B Metro M4:
swap PA12 and PA13 on SPI 2x3 header
swap A3 and A5
Comment out all frozen modules in CPX again to make room while waiting
for SPI flash.
