SPIM3 is faster than all other SPI blocks, and is capable of generating
a 32 MHz clock. However, it cannot be used at the same time as the BLE
radio without dedicating an additional 8 kB of RAM to it.
Therefore, some boards may want to disable this. Support pre-defining
NRFX_SPIM3_ENABLED on the command line to disable it on some bords.
Signed-off-by: Sean Cross <sean@xobs.io>
This adds preliminary support for the nRF52833, which is a variant of
the nRF52840 with half the RAM, half the flash, and fewer peripherals.
Signed-off-by: Sean Cross <sean@xobs.io>
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.
