stm32_i2s_calc_clk_div
ret = stm32_i2s_calc_clk_div(i2s, req->best_parent_rate, req->rate);
ret = stm32_i2s_calc_clk_div(i2s, parent_rate, rate);
ret = stm32_i2s_calc_clk_div(i2s, i2s_clock_rate,
ret = stm32_i2s_calc_clk_div(i2s, i2s_clock_rate,