/**
* \brief Gets the control interface index from a configuration node.
* \param conf Handle to the configuration node to be parsed.
* \return The control interface index if successful, otherwise a negative error code.
*/
int snd_config_get_ctl_iface(const snd_config_t *conf)
{
long v;
const char *str, *id;
int err;
err = snd_config_get_id(conf, &id);
if (err < 0)
return err;
err = snd_config_get_integer(conf, &v);
if (err >= 0) {
if (v < 0 || v > SND_CTL_ELEM_IFACE_LAST) {
_invalid_value:
SNDERR("Invalid value for %s", id);
return -EINVAL;
}
return v;
}
err = snd_config_get_string(conf, &str);
if (err < 0) {
SNDERR("Invalid type for %s", id);
return -EINVAL;
}
err = snd_config_get_ctl_iface_ascii(str);
if (err < 0)
goto _invalid_value;
return err;
}
/**
* \brief Parse control element id from the config
* \param conf the config tree to parse
* \param ctl_id the pointer to store the resultant control element id
* \param cardp the pointer to store the card index
* \param cchannelsp the pointer to store the number of channels (optional)
* \param hwctlp the pointer to store the h/w control flag (optional)
* \return 0 if successful, or a negative error code
*
* This function parses the given config tree to retrieve the control element id
* and the card index. It's used by softvol. External PCM plugins can use this
* function for creating or assigining their controls.
*
* cchannelsp and hwctlp arguments are optional. Set NULL if not necessary.
*/
int snd_pcm_parse_control_id(snd_config_t *conf, snd_ctl_elem_id_t *ctl_id, int *cardp,
int *cchannelsp, int *hwctlp)
{
snd_config_iterator_t i, next;
int iface = SND_CTL_ELEM_IFACE_MIXER;
const char *name = NULL;
long index = 0;
long device = -1;
long subdevice = -1;
int err;
assert(ctl_id && cardp);
*cardp = -1;
if (cchannelsp)
*cchannelsp = 2;
snd_config_for_each(i, next, conf) {
snd_config_t *n = snd_config_iterator_entry(i);
const char *id;
if (snd_config_get_id(n, &id) < 0)
continue;
if (strcmp(id, "comment") == 0)
continue;
if (strcmp(id, "card") == 0) {
const char *str;
long v;
if ((err = snd_config_get_integer(n, &v)) < 0) {
if ((err = snd_config_get_string(n, &str)) < 0) {
SNDERR("Invalid field %s", id);
goto _err;
}
*cardp = snd_card_get_index(str);
if (*cardp < 0) {
SNDERR("Cannot get index for %s", str);
err = *cardp;
goto _err;
}
} else
*cardp = v;
continue;
}
if (strcmp(id, "iface") == 0 || strcmp(id, "interface") == 0) {
const char *ptr;
if ((err = snd_config_get_string(n, &ptr)) < 0) {
SNDERR("field %s is not a string", id);
goto _err;
}
if ((err = snd_config_get_ctl_iface_ascii(ptr)) < 0) {
SNDERR("Invalid value for '%s'", id);
goto _err;
}
iface = err;
continue;
}
if (strcmp(id, "name") == 0) {
if ((err = snd_config_get_string(n, &name)) < 0) {
SNDERR("field %s is not a string", id);
goto _err;
}
continue;
}
if (strcmp(id, "index") == 0) {
if ((err = snd_config_get_integer(n, &index)) < 0) {
SNDERR("field %s is not an integer", id);
goto _err;
}
continue;
}
if (strcmp(id, "device") == 0) {
if ((err = snd_config_get_integer(n, &device)) < 0) {
SNDERR("field %s is not an integer", id);
goto _err;
}
continue;
}
if (strcmp(id, "subdevice") == 0) {
if ((err = snd_config_get_integer(n, &subdevice)) < 0) {
SNDERR("field %s is not an integer", id);
goto _err;
}
continue;
}
if (cchannelsp && strcmp(id, "count") == 0) {
long v;
if ((err = snd_config_get_integer(n, &v)) < 0) {
SNDERR("field %s is not an integer", id);
goto _err;
}
if (v < 1 || v > 2) {
SNDERR("Invalid count %ld", v);
goto _err;
}
*cchannelsp = v;
continue;
}
if (hwctlp && strcmp(id, "hwctl") == 0) {
if ((err = snd_config_get_bool(n)) < 0) {
SNDERR("The field %s must be a boolean type", id);
return err;
}
*hwctlp = err;
continue;
}
SNDERR("Unknown field %s", id);
return -EINVAL;
}
