From e55d735f84364d3b7d38104cee37c968e3797ea4 Mon Sep 17 00:00:00 2001 From: Takashi Sakamoto Date: Thu, 29 Sep 2016 08:57:23 +0900 Subject: [PATCH] ctl: improve documentation about TLV-related APIs 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 Signed-off-by: Takashi Iwai --- src/control/control.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/src/control/control.c b/src/control/control.c index 422582d4..40ee9b75 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 . */ 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 . */ 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 . */ int snd_ctl_elem_tlv_command(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id, const unsigned int *tlv) -- 2.47.1