ASoC: Add function "rl6231_get_pre_div" to correct the dmic clock calculation

Signed-off-by: Bard Liao <bardliao@realtek.com>
Signed-off-by: Oder Chiou <oder_chiou@realtek.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 47 insertions, 0 deletions

diff --git a/sound/soc/codecs/rl6231.c b/sound/soc/codecs/rl6231.c
index 96f3e906dfef..57e51c16e021 100644
--- a/sound/soc/codecs/rl6231.c
+++ b/sound/soc/codecs/rl6231.c
@@ -11,10 +11,57 @@
  */
 
 #include <linux/module.h>
+#include <linux/regmap.h>
 
 #include "rl6231.h"
 
 /**
+ * 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 parameter of dmic.
  *
  * @rate: base clock rate.