Implement sdioio for raspberrypi port

[FoamyGuy]

The core functionality of the implementation comes from https://github.com/adafruit/SdFat/. A few files needed altering to work embedded within CircuitPython and hooked up to the bindings.

Basic testing has been completed successfully on a Metro RP2350. Also enabled for Fruit Jam, but not tested yet, should work the same. board.SDIO_DATA is added to those two devices as a tuple of the 4 sdio data pins to match the existing sdioio documented example.

Currently the sdcard automount still uses SPI, and the SPI sdcard interface has some conflicting pins with the sdioio interface. When automount is enabled it holds a lock on those pins preventing them from being used for sdioio. The settings.toml config CIRCUITPY_SDCARD_USB already disabled the automount, but was still holding the pins even when set to false. This PR changes the behavior to not hold the pins when the config is False. I did not look into changing the automount over to use sdio, maybe that would be a good option in the long term? For right now you must have CIRCUITPY_SDCARD_USB = false in settings.toml to use this.

@mikeysklar You recently did a bunch of sd card testing. If you're interested in trying this out it would be appreciated.

[FoamyGuy]

pre-commit run -a was passing for me with all green. I had to manually run python3 tools/codeformat.py -v -c [file] against the files in the actions log to get it to actually format those files for me locally.

[mikeysklar]

Nice work, Foamy. This is the fastest setup I've seen. You cracked the 10 MB/s write speed. This is now competitive with Arduino code.

SDIO on RP2350 ~4x faster for bulk read / write than SPI mode.
SDIO on RP2350 ~10% slower for log/lines (small writes) than SPI mode.

Benchmarking using SD Card Performance Guide example code / configuration.

+-------------+-------+-------+-------+
|             | Bulk  | Bulk  | Log   |
|             | read  | write | lines |
| Bus         | MB/s  | MB/s  | /sec  |
+-------------+-------+-------+-------+
| RP2350 SPI  |  2.3  |  2.3  | 2581  |
|  @25MHz     |       |       |       |
+-------------+-------+-------+-------+
| ESP32-S3    |  7.1  |  4.5  | 1489  |
|  SDIO       |       |       |       |
|  @40MHz     |       |       |       |
+-------------+-------+-------+-------+
| RP2350 SDIO |  8.7  | 10.4  | 2278  |
|  @25MHz     |       |       |       |
|  (this PR)  |       |       |       |
+-------------+-------+-------+-------+
| SDIO vs SPI | 3.8x  | 4.5x  | 0.88x |
|  (RP2350)   | up    | up    | down  |
+-------------+-------+-------+-------+

Note: I did need to do one single hard power cycle - unplug - the board after updating to the new build to transition from SPI -> SDIO mode.

[mikeysklar]

Feather RP2040 Adalogger 5x improvement with SDIO over SPI for bulk rd/wr. Small bump up in log lines.

+----------------------------+------+-----+------+
| Board / Bus                | Wr   | Rd  | Log  |
+----------------------------+------+-----+------+
| Feather RP2040 Adalogger   |  1.9 | 1.8 | 1065 |
|  SPI (built-in)            |      |     |      |
+----------------------------+------+-----+------+
| ESP32-S3                   |  4.5 | 7.1 | 1489 |
|  4-bit SDIO @40MHz         |      |     |      |
+----------------------------+------+-----+------+
| Metro RP2350               | 10.4 | 8.7 | 2278 |
|  4-bit SDIO @25MHz         |      |     |      |
+----------------------------+------+-----+------+
| Feather RP2040 Adalogger   |  9.6 | 8.1 | 1160 |
|  SDIO @25MHz               |      |     |      |
+----------------------------+------+-----+------+
Wr/Rd = MB/s, Log = lines/sec

[mikeysklar]

Feather RP2350 ADA#6000 + SDIO Breakout ADA#4682

Good results nearly identical to the Metro RP2350

+---------------------------------+--------+------+------+------+
| Board (SDIO @25MHz)             | Chip   | Wr   | Rd   | Log  |
+---------------------------------+--------+------+------+------+
| Feather RP2040 Adalogger        | RP2040 |  9.6 |  8.1 | 1160 |
|  (onboard slot)                 |        |      |      |      |
+---------------------------------+--------+------+------+------+
| Metro RP2350                    | RP2350 | 10.4 |  8.7 | 2278 |
|  (onboard slot)                 |        |      |      |      |
+---------------------------------+--------+------+------+------+
| Feather RP2350 + #4682 breakout | RP2350 | 10.3 |  8.7 | 2352 |
|  (A0-A3 wiring)                 |        |      |      |      |
+---------------------------------+--------+------+------+------+
Wr/Rd = MB/s, Log = lines/sec.  All 4-bit SDIO @25MHz, best-of-3.

Breakout #4682	Feather	GPIO	SDIO	Wire
CLK	SCK	22	Clock	🟡 Yellow
CMD	MOSI	23	Command	🔵 Blue
D0	A0	26	Data 0	🟢 Green
D1	A1	27	Data 1	🟠 Orange
DAT2	A2	28	Data 2	🟣 Purple
D3	A3	29	Data 3	🟤 Brown
DET	MISO	20	Card-detect	⚪ White
3V	3V	—	Power	🔴 Red
GND	GND	—	Ground	⚫ Black

Compiled with :

CIRCUITPY_SDIOIO = 1

in:

ports/raspberrypi/boards/adafruit_feather_rp2350/mpconfigboard.mk

It costs 10 KB of flash / 2 KB of SRAM to enable SDIO by default for the Feather RP2350. It's not a lot, but also a little hard to justify as most people would not be using SDIO on the Feather RP2350.