CLK_CTRL_SRC_SHIFT
parent = (ctrl & data->clk_src_mask) >> CLK_CTRL_SRC_SHIFT;
ctrl |= (AUX_SEL << CLK_CTRL_SRC_SHIFT) & data->clk_src_mask;
ctrl |= (index << CLK_CTRL_SRC_SHIFT) & data->clk_src_mask;