+ * rl6231_get_pre_div - Return the value of pre divider.
+ *
+ * @map: map for setting.
+ * @reg: register.
+ * @sft: shift.
+ *
+ * Return the value of pre divider from given register value.
+ * Return negative error code for unexpected register value.
+ */
+int rl6231_get_pre_div(struct regmap *map, unsigned int reg, int sft)
+{
+ int pd, val;
+
+ regmap_read(map, reg, &val);
+
+ val = (val >> sft) & 0x7;
+
+ switch (val) {
+ case 0:
+ case 1:
+ case 2:
+ case 3:
+ pd = val + 1;
+ break;
+ case 4:
+ pd = 6;
+ break;
+ case 5:
+ pd = 8;
+ break;
+ case 6:
+ pd = 12;
+ break;
+ case 7:
+ pd = 16;
+ break;
+ default:
+ pd = -EINVAL;
+ break;
+ }
+
+ return pd;
+}
+EXPORT_SYMBOL_GPL(rl6231_get_pre_div);
+
+/**
+ * rl6231_calc_dmic_clk - Calculate the frequency divider parameter of dmic.