feat(cherryusb): add cherryusb device & host demo

[sakumisu]

raspberrypi/pico-sdk#2212

[lurch]

This should probably just include https://github.com/raspberrypi/pico-examples/blob/develop/freertos/FreeRTOSConfig_examples_common.h rather than adding a separate copy of the file to the repo?

[sakumisu]

https://github.com/raspberrypi/pico-examples/tree/master/freertos i use this template, freertos uses FreeRTOSConfig.h not FreeRTOSConfig_examples_common.h, so i don't know why add FreeRTOSConfig_examples_common.h.

[lurch]

I think maybe you could just do #include ../../../freertos/FreeRTOSConfig_examples_common.h in your FreeRTOSConfig.h? (although perhaps there's a "nicer" way of doing that without all the ../ ?) And then you could remove FreeRTOSConfig_examples_common.h from this PR. 🤷

[sakumisu]

How about using FreeRTOSConfig.h only? If configs in FreeRTOSConfig_examples_common.h have conflict with other demo like less memory, no feature support like sem & mutex disabled, users will be confused.

[lurch]

Hmmm I just checked and I hadn't realised that FreeRTOSConfig_examples_common.h doesn't use the normal

#ifndef SOME_SETTING
#define SOME_SETTING some_value
#endif

pattern. But @peterharperuk understands all of this much better than I do! 😆

[lurch]

It seems that this usb_config.h is identical to the other usb_config.h - perhaps it makes sense to add just one copy of the file to the repo (in usb/cherryusb/ ?), and have both examples share it? 🤔
(i.e. like what is done with https://github.com/raspberrypi/pico-examples/blob/develop/freertos/FreeRTOSConfig_examples_common.h and https://github.com/raspberrypi/pico-examples/blob/develop/pico_w/wifi/lwipopts_examples_common.h and https://github.com/raspberrypi/pico-examples/blob/develop/pico_w/wifi/mbedtls_config_examples_common.h )

[sakumisu]

This is an optional config for users to modify.

[sakumisu]

Like enable log, enable bufsize for performance, enable more class instances and so on.

[lurch]

Still, perhaps it makes sense to have a per-example usb_config.h (where the users can add their optional customisation) which then does #include "usb_config_examples_common.h" ? (just to reduce the amount of duplication)

[sakumisu]

Still, perhaps it makes sense to have a per-example usb_config.h (where the users can add their optional customisation) which then does #include "usb_config_examples_common.h" ? (just to reduce the amount of duplication)

I know what you mean, yeah, reduce the duplication, also freertos. I will modify.

[sakumisu]

Have done. And i see pico_w demo has FreeRTOSConfig_examples_common.h, so i move this into config dir.

[lurch]

Have done.

Thanks 👍 But I'm still not sure if it makes sense to have both freertos/FreeRTOSConfig_examples_common.h and usb/cherryusb/config/FreeRTOSConfig_examples_common.h, which appear to be identical copies of each other?

[sakumisu]

In addition, current directory structure i think need to modify.