media: imx7-media-csi: Check the return value from clk_prepare_enable()

clk_prepare_enable() may fail, so we should better check its return value
and propagate it in the case of error.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Tested-by: Rui Miguel Silva <rmfrfs@gmail.com>
Reviewed-by: Rui Miguel Silva <rmfrfs@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/staging/media/imx/imx7-media-csi.c

@@ -390,17 +390,23 @@ static void imx7_csi_error_recovery(struct imx7_csi *csi)
 	imx7_csi_hw_enable(csi);
 }
 
-static void imx7_csi_init(struct imx7_csi *csi)
+static int imx7_csi_init(struct imx7_csi *csi)
 {
+	int ret;
+
 	if (csi->is_init)
-		return;
+		return 0;
 
-	clk_prepare_enable(csi->mclk);
+	ret = clk_prepare_enable(csi->mclk);
+	if (ret < 0)
+		return ret;
 	imx7_csi_hw_reset(csi);
 	imx7_csi_init_interface(csi);
 	imx7_csi_dmareq_rff_enable(csi);
 
 	csi->is_init = true;
+
+	return 0;
 }
 
 static void imx7_csi_deinit(struct imx7_csi *csi)
@@ -513,7 +519,7 @@ static int imx7_csi_link_setup(struct media_entity *entity,
 
 init:
 	if (csi->sink || csi->src_sd)
-		imx7_csi_init(csi);
+		ret = imx7_csi_init(csi);
 	else
 		imx7_csi_deinit(csi);