diff --git a/include/sound/cs35l35.h b/include/sound/cs35l35.h
index de92e452bf93..983c610eba2e 100644
--- a/include/sound/cs35l35.h
+++ b/include/sound/cs35l35.h
@@ -80,6 +80,8 @@ struct cs35l35_platform_data {
 	bool stereo;
 	/* serial port drive strength */
 	int sp_drv_str;
+	/* serial port drive in unused slots */
+	int sp_drv_unused;
 	/* Boost Power Down with FET */
 	bool bst_pdn_fet_on;
 	/* Boost Voltage : used if ClassH Algo Enabled */
diff --git a/sound/soc/codecs/cs35l35.c b/sound/soc/codecs/cs35l35.c
index 48b45dc904ea..5a9fe5addb86 100644
--- a/sound/soc/codecs/cs35l35.c
+++ b/sound/soc/codecs/cs35l35.c
@@ -789,6 +789,11 @@ static int cs35l35_codec_probe(struct snd_soc_codec *codec)
 				CS35L35_SP_DRV_MASK,
 				cs35l35->pdata.sp_drv_str <<
 				CS35L35_SP_DRV_SHIFT);
+	if (cs35l35->pdata.sp_drv_unused)
+		regmap_update_bits(cs35l35->regmap, CS35L35_SP_FMT_CTL3,
+				   CS35L35_SP_I2S_DRV_MASK,
+				   cs35l35->pdata.sp_drv_unused <<
+				   CS35L35_SP_I2S_DRV_SHIFT);
 
 	if (classh->classh_algo_enable) {
 		if (classh->classh_bst_override)
@@ -1169,6 +1174,8 @@ static int cs35l35_handle_of_data(struct i2c_client *i2c_client,
 
 	if (of_property_read_u32(np, "cirrus,sp-drv-strength", &val32) >= 0)
 		pdata->sp_drv_str = val32;
+	if (of_property_read_u32(np, "cirrus,sp-drv-unused", &val32) >= 0)
+		pdata->sp_drv_unused = val32 | CS35L35_VALID_PDATA;
 
 	pdata->stereo = of_property_read_bool(np, "cirrus,stereo-config");
 
diff --git a/sound/soc/codecs/cs35l35.h b/sound/soc/codecs/cs35l35.h
index e27a7fef5fb1..c203081fc94c 100644
--- a/sound/soc/codecs/cs35l35.h
+++ b/sound/soc/codecs/cs35l35.h
@@ -190,6 +190,10 @@
 #define CS35L35_AMP_GAIN_ZC_MASK	0x10
 #define CS35L35_AMP_GAIN_ZC_SHIFT	4
 
+/* CS35L35_SP_FMT_CTL3 */
+#define CS35L35_SP_I2S_DRV_MASK		0x03
+#define CS35L35_SP_I2S_DRV_SHIFT	0
+
 /* Class H Algorithm Control */
 #define CS35L35_CH_STEREO_MASK		0x40
 #define CS35L35_CH_STEREO_SHIFT		6