nRF UART nrfx drivers (nRF UARTE 0) won't build

[oxymoron87]

Describe the bug
Can't build project for set(BOARD nrf52840_pca10056) with CONFIG_UART_0_NRF_UARTE=y. Build process fails on undeclared symbol.
[build] ../zephyr/drivers/serial/uart_nrfx_uarte.c:581:5: error: DT_NORDIC_NRF_UARTE_UART_0_CURRENT_SPEED' undeclared here (not in a function); did you mean 'DT_NORDIC_NRF_UART_UART_0_CURRENT_SPEED'?
[build] DT_NORDIC_NRF_UARTE_UART_##idx##_CURRENT_SPEED,\
[build] ^
[build] ../zephyr/drivers/serial/uart_nrfx_uarte.c:689:2: note: in expansion of macro 'UART_NRF_UARTE_DEVICE'
[build] UART_NRF_UARTE_DEVICE(0);
[build] ^~~~~~~~~~~~~~~~~~~~~
[build] ../zephyr/drivers/serial/uart_nrfx_uarte.c:597:4: error: 'DT_NORDIC_NRF_UARTE_UART_0_BASE_ADDRESS' undeclared here (not in a function); did you mean 'DT_NORDIC_NRF_UART_UART_0_BASE_ADDRESS'?
[build] DT_NORDIC_NRF_UARTE_UART_##idx##_BASE_ADDRESS, \
[build] ^
[build] ../zephyr/drivers/serial/uart_nrfx_uarte.c:689:2: note: in expansion of macro 'UART_NRF_UARTE_DEVICE'
[build] UART_NRF_UARTE_DEVICE(0);
[build] ^~~~~~~~~~~~~~~~~~~~~
etc.

To Reproduce
Steps to reproduce the behavior:

1. set CONFIG_UART_0_NRF_UARTE=y in prj.conf
2. mkdir build; cd build
3. cmake -GNinja -DBOARD=nrf52840_pca10056
4. ninja
5. See error

Additional context
Symbols are generated to
./build/zephyr/include/generated/generated_dts_board.conf (DT_NORDIC_NRF_UART_UART_0_CURRENT_SPEED=115200)
but for UART and not for UARTE even if UARTE is selected.

Impact
Can't use nRF UARTE instead of nRF UART

Environment (please complete the following information):

• OS: Linux
• Toolchain: GNU ARM GCC
• ZephyrOS commit: 48f4932

[jakub-uC]

This is philosophical problem, what shall be done in DT and what in Kconfig.

We agreed that Zephyr will be Linux-like so in Kconfig you set a driver to be compiled and in DT peripheral to be used.

Please refer to issue: #11792

To fix it simply edit file:
zephyr/boards/arm/nrf52840_pca10056/nrf52840_pca10056.dts
you need to change line 92:
compatible = "nordic,nrf-uart"; to compatible = "nordic,nrf-uarte";

[chris-schra]

@jarz-nordic could #11932, #11792 or this one please stay open? I think this is a real problem, especially keeping newbies in mind. I always wonder why there aren't more hints in code. In this case, for example, it could be something like

#if !defined(DT_NORDIC_NRF_UARTE_UART_0_CURRENT_SPEED) && defined(DT_NORDIC_NRF_UART_UART_0_CURRENT_SPEED)
#error Please set UART0 compatible = "nordic,nrf-uarte" in DTS
#endif

in uart_nrfx_uarte.c

Again, this is just an example and I think that it's not good to place it there because it statically checks for UARTE0 (instead of being generic like UART_NRF_UARTE_DEVICE(idx))

Should I create an Improvement issue for "Help newbies with compiler macros"? Eg, what about adding an extra build step which calls a "config_check.h" afterwards and everyone who wants to add checks could just include for example "config_check_nrfx_uarte.h" there and define checks in that header file?

[jakub-uC]

@derchrismakaio : I am not an expert to say if this is good idea or not.
I would ask: @anangl , @galak or @Mierunski , they were working a lot on Device Tree.

[CodingGhost]

I am a newbie here and have to agree @chris-makaio.
I had no Idea what to do.