soc: soundwire: Check for clock source before clock switch

Check for soundwire clock source before clock switch to avoid
redundant clock switch for the same clock source.

Change-Id: I8a7a116cc956f427af677b413928dace5a39a23d
Signed-off-by: Sudheer Papothi <spapothi@codeaurora.org>
diff --git a/soc/swr-mstr-ctrl.c b/soc/swr-mstr-ctrl.c
index 598b269..edc772d 100644
--- a/soc/swr-mstr-ctrl.c
+++ b/soc/swr-mstr-ctrl.c
@@ -3074,9 +3074,18 @@
 		 * next activity on soundwire will request clock from new clock
 		 * source.
 		 */
+		if (!data) {
+			dev_err(swrm->dev, "%s: data is NULL for id:%d\n",
+				__func__, id);
+			ret = -EINVAL;
+			break;
+		}
 		mutex_lock(&swrm->mlock);
-		if (swrm->state == SWR_MSTR_UP)
-			swrm_device_suspend(&pdev->dev);
+		if (swrm->clk_src != *(int *)data) {
+			if (swrm->state == SWR_MSTR_UP)
+				swrm_device_suspend(&pdev->dev);
+			swrm->clk_src = *(int *)data;
+		}
 		mutex_unlock(&swrm->mlock);
 		break;
 	case SWR_CLK_FREQ:
diff --git a/soc/swr-mstr-ctrl.h b/soc/swr-mstr-ctrl.h
index 1987e0f..c404fc6 100644
--- a/soc/swr-mstr-ctrl.h
+++ b/soc/swr-mstr-ctrl.h
@@ -178,6 +178,7 @@
 	u32 swr_irq_wakeup_capable;
 	int hw_core_clk_en;
 	int aud_core_clk_en;
+	int clk_src;
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *debugfs_swrm_dent;
 	struct dentry *debugfs_peek;