asoc: wcd938x: Add vdd-buck as on demand supply

On lagoon, vdd-buck need to be dynamic supply.
Add required support to handle buck as dynamic supply.

Change-Id: If6c27fffe0d0c44f178e61a6eae6ef63775c8988
Signed-off-by: Laxminath Kasam <lkasam@codeaurora.org>

asoc/codecs/msm-cdc-supply.c

@@ -119,6 +119,47 @@ static int msm_cdc_check_supply_param(struct device *dev,
 	return 0;
 }
 
+/*
+ * msm_cdc_is_ondemand_supply:
+ *	return if ondemand supply true or not
+ *
+ * @dev: pointer to codec device
+ * @supplies: pointer to regulator bulk data
+ * @cdc_vreg: pointer to platform regulator data
+ * @num_supplies: number of supplies
+ * @supply_name: supply name to be checked
+ *
+ * Return true/false
+ */
+bool msm_cdc_is_ondemand_supply(struct device *dev,
+				struct regulator_bulk_data *supplies,
+				struct cdc_regulator *cdc_vreg,
+				int num_supplies,
+				char *supply_name)
+{
+	bool rc = false;
+	int ret, i;
+
+	if ((!supply_name) || (!supplies)) {
+		pr_err("%s: either dev or supplies or cdc_vreg is NULL\n",
+				__func__);
+		return rc;
+	}
+	/* input parameter validation */
+	ret = msm_cdc_check_supply_param(dev, cdc_vreg, num_supplies);
+	if (ret)
+		return rc;
+
+	for (i = 0; i < num_supplies; i++) {
+		if (cdc_vreg[i].ondemand &&
+			!strcmp(cdc_vreg[i].name, supply_name))
+			return true;
+	}
+
+	return rc;
+}
+EXPORT_SYMBOL(msm_cdc_is_ondemand_supply);
+
 /*
  * msm_cdc_disable_ondemand_supply:
  *	Disable codec ondemand supply