doc: clarify that the high-level set value callback is optional
authorBartosz Golaszewski <bartekgola@gmail.com>
Fri, 26 Jan 2018 09:53:23 +0000 (10:53 +0100)
committerBartosz Golaszewski <bartekgola@gmail.com>
Fri, 26 Jan 2018 09:53:23 +0000 (10:53 +0100)
commit3eb0c52ad5f1ef03ca3a5d8dbcf6512873d1fef1
treea3bd2a5b654b36046f87a2847071acc6a436a7b1
parent7bddc61ae570c04a1e7b6da2a83d9ff8934d53ef
doc: clarify that the high-level set value callback is optional

Users have reported it as confusing so make it clear.

Signed-off-by: Bartosz Golaszewski <bartekgola@gmail.com>
include/gpiod.h