diff --git a/drivers/nvmem/rockchip-otp.c b/drivers/nvmem/rockchip-otp.c
index 0ec78b5e19e7..2c0feb036f3f 100644
--- a/drivers/nvmem/rockchip-otp.c
+++ b/drivers/nvmem/rockchip-otp.c
@@ -78,9 +78,9 @@ struct rockchip_data {
 struct rockchip_otp {
 	struct device *dev;
 	void __iomem *base;
-	struct clk_bulk_data *clks;
 	struct reset_control *rst;
 	const struct rockchip_data *data;
+	struct clk_bulk_data clks[];
 };
 
 static int rockchip_otp_reset(struct rockchip_otp *otp)
@@ -424,7 +424,7 @@ static int rockchip_otp_probe(struct platform_device *pdev)
 	if (!data)
 		return dev_err_probe(dev, -EINVAL, "failed to get match data\n");
 
-	otp = devm_kzalloc(&pdev->dev, sizeof(struct rockchip_otp),
+	otp = devm_kzalloc(&pdev->dev, struct_size(otp, clks, data->num_clks),
 			   GFP_KERNEL);
 	if (!otp)
 		return -ENOMEM;
@@ -436,11 +436,6 @@ static int rockchip_otp_probe(struct platform_device *pdev)
 		return dev_err_probe(dev, PTR_ERR(otp->base),
 				     "failed to ioremap resource\n");
 
-	otp->clks = devm_kcalloc(dev, data->num_clks, sizeof(*otp->clks),
-				 GFP_KERNEL);
-	if (!otp->clks)
-		return -ENOMEM;
-
 	for (i = 0; i < data->num_clks; ++i)
 		otp->clks[i].id = data->clks[i];