This code is shared by most parts, except where not all the #ifdefs
inside the tick function were present in all ports. This mostly would
have broken gamepad tick support on non-samd ports.
The "ms32" and "ms64" variants of the tick functions are introduced
because there is no 64-bit atomic read. Disabling interrupts avoids
a low probability bug where milliseconds could be off by ~49.5 days
once every ~49.5 days (2^32 ms).
Avoiding disabling interrupts when only the low 32 bits are needed is a minor
optimization.
Testing performed: on metro m4 express, USB still works and
time.monotonic_ns() still counts up
This also improves Palette so it stores the original RGB888 colors.
Lastly, it adds I2CDisplay as a display bus to talk over I2C. Particularly
useful for the SSD1306.
Fixes#1828. Fixes#1956
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.
This is not strictly needed in order for #1056 to be resolved,
because the "make long-lived" machinery is unaware of this pointer.
However, as UARTs are assumed to be long-lived, this change is
beneficial because it moves the long-lived buffer into the upper
memory area with other long-lived objects, instead of remaining in
the low heap.
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.
We added a check to make sure the pins are in a high state before
initing the bus. This leads to a friendly error message when someone
forgets to add the pull up resistors to their circuit.
The following error occurs when building with gcc 5.4.1 (debian stretch):
common-hal/busio/UART.c:104:83: error: 'sercom_index' may be used uninitialized in this function [-Werror=maybe-uninitialized]
sercom_insts[rx->sercom[j].index]->USART.CTRLA.bit.ENABLE == 0) ||
It may be related to the addition of rx-only UARTs; gcc is unable
to infer the intended relationship between have_tx and sercom_index
being set (I am still not entirely confident of it myself)
