boards/*nrf52*: Enable tinyusb support for all nrf52-based boards

[mguetschow]

Contribution description

TinyUSB support is given for all nrf52-based boards, but only explicitly enabled for some selected ones. This PR enables support for all such boards.

I also noticed that usb_board_reset would currently only be enabled with the usbus stack, fixed that as well.

Testing procedure

make BOARD=feather-nrf52840-sense -C tests/pkg/tinyusb_cdc_acm_stdio flash term or any other nrf52-based board. Without this PR, only works for selected boards (e.g., nrf52840dk). Flash again to test the usb_board_reset feature.

Issues/PRs references

Hinted to by @dylad on Matrix

[dylad]

Did you tried usb_board_reset alongside with stdio_tinyusb_cdc_acm ? Does it work well ?

[riot-ci]

Murdock results

✔️ PASSED

a715fce Update cpu/nrf52/Makefile.features

Success	Failures	Total	Runtime
10177	0	10178	12m:48s

Artifacts

• Documentation preview

[dylad]

If it works, we're all good :)

[mguetschow]

FWIW, this seems to be a (small) subset of #18998

[mguetschow]

Thanks CI :) good catch: apparently not all nRF52 boards have the necessary USBD peripheral, see https://docs.nordicsemi.com/bundle/struct_nrf52/page/struct/nrf52.html

[mguetschow]

With the last commit, I've moved FEATURES_PROVIDED += periph_usbdev and FEATURES_PROVIDED += tinyusb_dev to be CPU instead of board dependant. That should enable tinyusb for all nrf52-based boards that actually have the USBD peripheral.

Disclaimer: I'm not sure whether this is the right way to model this in RIOT, please have a closer look.

[dylad]

I think we have an issue here.
periph_usbdev is designed to be used by USBUS only.
So you must not provide this feature alongside with tinyusb_device.
tinyUSB provides its own low level peripheral driver.

[dylad]

perhaps we can try to summon @gschorcht for its guidance here.

[mguetschow]

Ah really, I understood it as "the CPU has a usb peripheral", which is also what is documented here: https://doc.riot-os.org/md_doc_2doxygen_2src_2feature__list.html#autotoc_md2318

[mguetschow]

Anyway the boards before also exposed periph_usbdev and using tinyusb was perfectly possible.

[dylad]

In fact, what @gschorcht wanted to do was:
use USBUS by default for highlevel_stdio
but, if for whatever reason, tinyUSB is used by user switch the USB stack to tinyUSB and thus use stdio_tinyusb_cdc_acm.
In the end, the board can provide periph_usbdev but if tinyUSB is used, USBUS must be discarded.

[dylad]

Moreover, is it really a good idea to define the USB at CPU level ?
I think it's done at board level currently because a board doesn't always expose USB pins.

[mguetschow]

You can confirm this with make BOARD=feather-nrf52840-sense -C examples/hello-world info-modules which still includes usbus.

[mguetschow]

Moreover, is it really a good idea to define the USB at CPU level ? I think it's done at board level currently because a board doesn't always expose USB pins.

That is indeed a good point.

So maybe we rather want the following: each board defines periph_usb if present, and the cpu can check for periph_usbdev and then additionally set tinyusb_device?

[dylad]

So maybe we rather want the following: each board defines periph_usb if present, and the cpu can check for periph_usbdev and then additionally set tinyusb_device?

Let's try this way.

[mguetschow]

See the new commit (sorry for the force-push).

[mguetschow]

Hum :/

Modules should not check the content of FEATURES_PROVIDED/REQUIRED/OPTIONAL:
	cpu/nrf52/Makefile.features:17:ifneq (,$(filter periph_usbdev,$(FEATURES_PROVIDED)))

[dylad]

Maybe you could tried to check periph_usbdev against USEMODULE or FEATURES_USED instead ?

[mguetschow]

But that's not what I want: I want to express that tinyusb_device is supported iff periph_usbdev is on any nrf52 boards, not that the former is supported only if I actually want to use the latter.