amixer_mgr_get_ctrl_blk
int (*amixer_mgr_get_ctrl_blk)(void **rblk);
.amixer_mgr_get_ctrl_blk = amixer_mgr_get_ctrl_blk,
.amixer_mgr_get_ctrl_blk = amixer_mgr_get_ctrl_blk,
err = hw->amixer_mgr_get_ctrl_blk(&mgr->ctrl_blk);