[PATCH] Documentation about RS485 serial communications

[Claudio Scordino]

Hi Randy,

	thank you for the feedback.

[...]

> 
> TIOC[SG]RS485 are #defined in <asm-generic/ioctls.h>, so
> #include <asm-generic/ioctls.h>
> here and/or below (in userspace program).
> 

I noticed that for some architectures (e.g., cris) these ioctls are defined also in arch/cris/include/asm/ioctls.h, and with different values with respect to the values defined on asm-generic/ioctls.h.

Therefore, I wasn't completely sure that the values defined in asm-generic are being used in every driver...

Best regards,

	Claudio