Add non-DMA SPI support.

[tannewt]

This fixes SPI with PSRAM allocated buffers. DMA with SPI2 was
attempted but produced junk output. This manual copy is less than
2x slower than DMA when not interrupted.

Fixes #3339

[tannewt]

@emard please test artifacts from this build once it completes. Thanks!

[emard]

Currently I have tested this: adafruit-circuitpython-espressif_saola_1_wroom-en_US-20200911-9256e6b.bin everything works adafruit-circuitpython-espressif_saola_1_wrover-en_US-20200911-9256e6b.bin doesn't work

>> import spiloopback

loopback IO35-IO37 bytearray(b'\x00\x00\x00\x00') fail bytearray(b'\x00\x00\x00\x00') fail bytearray(b'\x00\x00\x00\x00') fail bytearray(b'\x00\x00\x00\x00') fail

…

On 9/11/20, Scott Shawcroft ***@***.***> wrote: @emard please test artifacts from this build once it completes. Thanks! -- You are receiving this because you were mentioned. Reply to this email directly or view it on GitHub: #3393 (comment)

[tannewt]

Try a file from here: espressif_saola_1_wrover.zip

The PR artifacts aren't available on S3.

[emard]

YEEESSS this one is fully working on WROVER and 2MB free! I don't see any speed difference compared to WROOM. However, if I use 64K buffer instead of 4K I get some strange syntax error inside of the code where correct syntax is.

…

On 9/11/20, Scott Shawcroft ***@***.***> wrote: Try a file from here: [espressif_saola_1_wrover.zip](https://github.com/adafruit/circuitpython/files/5211265/espressif_saola_1_wrover.zip) The PR artifacts aren't available on S3. -- You are receiving this because you were mentioned. Reply to this email directly or view it on GitHub: #3393 (comment)

[tannewt]

Strange syntax errors tend to happen when the host OS hasn't fully flushed it's writes to the filesystem.

[emard]

OK!
I reloaded again and now it seems ok 64K buffer is working!

[emard]

Regarding latest SPI, Is SD card supposed to work on WROVER?
I tried to mount SD card

import sdmount
Traceback (most recent call last):
File "", line 1, in
File "sdmount.py", line 31, in
File "adafruit_sdcard.py", line 116, in init
File "adafruit_sdcard.py", line 177, in _init_card
File "adafruit_sdcard.py", line 155, in _init_card
OSError: couldn't determine SD card version

If I remove SD card then it prints:

OSError: no SD card

[tannewt]

You are the first to try. Please file a separate issue. This might be default speed related or the MOSI state.

[tannewt]

@hierophect Please take a look.

[hierophect]

I don't see any issues with the Saleae. However, I'm unable to get my standard BMP_280 test working on this or the old pre-sram version, and it sounds like there may still be an issue with the SD card similar to the one on STM32-S2. I'll investigate those and make new issues if required.