drivers/led: add LEDX_IS_PRESENT defines

[krzysztof-cabaj]

Contribution description

Currently LEDX_ON, LEDX_OFF, etc. are defined in the board.h (or board_common.h or similar) files. However, various boards could have from 0 to 8 internal LEDs and to write portable code each call of LEDX_... should be protected by #ifdef LEDX_... . Including led.h header file resolve this issue and defines empty LEDX_... if LED is not present for given board. However, after including led.h there is no possibility to check if given board, really posses particular LED.

This PR adds LEDX_IS_PRESENT define for each presented LED at given board.

Testing procedure

This code snippet:

#if defined LED0_IS_PRESENT
 printf("LED0_IS_PRESENT defined.\n");
#endif

#if defined LED1_IS_PRESENT
 printf("LED1_IS_PRESENT defined.\n");
#endif

#if defined LED2_IS_PRESENT
 printf("LED2_IS_PRESENT defined.\n");
#endif

Should show real number of first three LEDs, for example:

LED0_IS_PRESENT defined.
LED1_IS_PRESENT defined.

in native board.

Issues/PRs references

None

[maribu]

Looks good to me, but the CI will insist on the documentation.

I do agree that the name is self-documenting, but the CI doesn't have this intuition and will insistent anyway.

[maribu]

Would you mind to squash the two commits into one?

[krzysztof-cabaj]

Squashed.

[maribu]

Hmm, automerge didn't seem to work here: There is no job running on Murdock. Let's turn it off and on again.

[maribu]

Ahh, my fault 😅

[riot-ci]

Murdock results

✔️ PASSED

a813e97 drivers/led: add LEDX_IS_PRESENT defines

Success	Failures	Total	Runtime
10065	0	10066	14m:16s

Artifacts

• Documentation preview

[maribu]

Thx for your contribution 😄