Signed-off-by: Nihal Jere <nihal@xxxxxxxxxxxxx> --- include/control.h | 38 +++++++++++++++++++++++++++++++++++++- src/control/control.c | 5 +++++ 2 files changed, 42 insertions(+), 1 deletion(-) diff --git a/include/control.h b/include/control.h index e386ecec..47e462fd 100644 --- a/include/control.h +++ b/include/control.h @@ -152,7 +152,43 @@ typedef struct _snd_ctl_elem_id snd_ctl_elem_id_t; */ typedef struct _snd_ctl_elem_list snd_ctl_elem_list_t; -/** CTL element info container */ +/** CTL element info container + * + * snd_ctl_elem_info_t can be allocated, cleared, and copied in the same + * way as #snd_ctl_elem_value_t, using the analogous functions. + * + * The ID can be filled in in the same way as for snd_ctl_elem_value_t, + * substituting snd_ctl_elem_value_* functions for snd_ctl_elem_info_* + * functions. See #snd_ctl_elem_value_t for details. + * + * The ID or numid must be set before calling snd_ctl_elem_info. + * + * \code + * snd_ctl_t* ctl; + * snd_ctl_elem_info_t* info; + * snd_ctl_elem_id_t* id; + * + * // Allocate info + * snd_ctl_elem_info_malloc(&info); + * + * // Obtain id, setup ctl... + * + * // set id + * snd_ctl_elem_info_set_id(info, id); + * // OR just set numid (more applicable if you don't have an id) + * snd_ctl_elem_info_set_id(info, snd_ctl_elem_id_get_numid(id)); + * + * // Get info from driver + * snd_ctl_elem_info(ctl, info); + * + * // Do things with info... + * + * // Cleanup + * snd_ctl_elem_info_free(info); + * \endcode + * + * The above example excludes error checking for the sake of readability. + */ typedef struct _snd_ctl_elem_info snd_ctl_elem_info_t; /** CTL element value container. diff --git a/src/control/control.c b/src/control/control.c index 3930c7b1..e346fa6b 100644 --- a/src/control/control.c +++ b/src/control/control.c @@ -417,6 +417,11 @@ int snd_ctl_elem_list(snd_ctl_t *ctl, snd_ctl_elem_list_t *list) /** * \brief Get CTL element information + * + * The object "info" must be allocated and the ID or numid must be filled + * prior to calling this function. + * See #snd_ctl_elem_info_t to learn more. + * * \param ctl CTL handle * \param info CTL element id/information pointer * \return 0 on success otherwise a negative error code -- 2.32.0
