The documentation gives no hints to users about format of TLV data.
This commit add hints to construct/parse the information.
Signed-off-by: Takashi Sakamoto o-takashi@sakamocchi.jp --- src/control/control.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)
diff --git a/src/control/control.c b/src/control/control.c index 422582d..40ee9b7 100644 --- a/src/control/control.c +++ b/src/control/control.c @@ -918,6 +918,13 @@ static int snd_ctl_tlv_do(snd_ctl_t *ctl, int op_flag, * \param tlv An array with members of unsigned int type. * \param tlv_size The length of the array. * \return 0 on success otherwise a negative error code + * + * The format of an array of \a tlv argument is: + * tlv[0]: Type. One of SND_CTL_TLVT_XXX. + * tlv[1]: Length. The length of value in units of byte. + * tlv[2..]: Value. Depending on the type. + * + * Details are described in <sound/tlv.h>. */ int snd_ctl_elem_tlv_read(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id, unsigned int *tlv, unsigned int tlv_size) @@ -948,6 +955,13 @@ int snd_ctl_elem_tlv_read(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id, * \retval 0 on success * \retval >0 on success when value was changed * \retval <0 a negative error code + * + * The format of an array of \a tlv argument is: + * tlv[0]: Type. One of SND_CTL_TLVT_XXX. + * tlv[1]: Length. The length of value in units of byte. + * tlv[2..]: Value. Depending on the type. + * + * Details are described in <sound/tlv.h>. */ int snd_ctl_elem_tlv_write(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id, const unsigned int *tlv) @@ -965,6 +979,13 @@ int snd_ctl_elem_tlv_write(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id, * \retval 0 on success * \retval >0 on success when value was changed * \retval <0 a negative error code + * + * The format of an array of \a tlv argument is: + * tlv[0]: Type. One of SND_CTL_TLVT_XXX. + * tlv[1]: Length. The length of value in units of byte. + * tlv[2..]: Value. Depending on the type. + * + * Details are described in <sound/tlv.h>. */ int snd_ctl_elem_tlv_command(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id, const unsigned int *tlv)