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author | Bartosz Golaszewski <bartekgola@gmail.com> | 2017-10-24 10:20:47 +0200 |
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committer | Bartosz Golaszewski <bartekgola@gmail.com> | 2017-10-24 10:20:47 +0200 |
commit | e567cb14f0eadb159fca52ba31d21895e9185e6e (patch) | |
tree | 28c0e8fca8d6cf85221190effe1cfd3d3e947deb /include | |
parent | 030f17e6572d4277c05d2eefffa091cd69ab43cb (diff) | |
download | external_libgpiod-e567cb14f0eadb159fca52ba31d21895e9185e6e.tar.gz external_libgpiod-e567cb14f0eadb159fca52ba31d21895e9185e6e.tar.bz2 external_libgpiod-e567cb14f0eadb159fca52ba31d21895e9185e6e.zip |
doc: extend the introduction
Add some additional info about the way the API is logically ordered
and a note on error handling.
Signed-off-by: Bartosz Golaszewski <bartekgola@gmail.com>
Diffstat (limited to 'include')
-rw-r--r-- | include/gpiod.h | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/include/gpiod.h b/include/gpiod.h index fa4c7b9..b1050f6 100644 --- a/include/gpiod.h +++ b/include/gpiod.h @@ -22,10 +22,24 @@ extern "C" { /** * @mainpage libgpiod public API * - * This is the documentation of the public API exported by libgpiod. + * This is the complete documentation of the public API made available to + * users of libgpiod. * - * <p>These functions and data structures allow to use all the functionalities - * exposed by the linux GPIO character device interface. + * <p>The public header is logically split into two high-level parts: the + * simple API and the low-level API. The former allows users to easily + * interact with the GPIOs in the system without dealing with the low-level + * data structures and resource control. The latter gives the user much more + * fine-grained control over the GPIO interface. + * + * <p>The low-level API is further logically split into several parts such + * as: GPIO chip & line operators, iterators, GPIO events handling etc. + * + * <p>General note on error handling: all routines exported by libgpiod set + * errno to one of the error values defined in errno.h upon failure. The way + * of notifying the caller that an error occurred varies between functions, + * but in general a function that returns an int, returns -1 on error, while + * a function returning a pointer bails out on error condition by returning + * a NULL pointer. */ struct gpiod_chip; |