conf_get_subtree
snd_config_t *conf_get_subtree(snd_config_t *root, const char *key1, const char *key2);
pcm_config = conf_get_subtree(card_config, "pcm", NULL);
if (conf_get_subtree(node2, "PLAYBACK", NULL))
if (conf_get_subtree(node2, "CAPTURE", NULL))
pcm_config = conf_get_subtree(card_config, key, NULL);
pcm_data->pcm_config = conf_get_subtree(card_config, key, NULL);
cfg = conf_get_subtree(cfg, "test", NULL);
default_pcm_config = conf_get_subtree(global_config, "pcm", NULL);