diff --git a/drivers/phy/rockchip/phy-rockchip-naneng-combphy.c b/drivers/phy/rockchip/phy-rockchip-naneng-combphy.c
index 0351ed80aafe..6964c473611d 100644
--- a/drivers/phy/rockchip/phy-rockchip-naneng-combphy.c
+++ b/drivers/phy/rockchip/phy-rockchip-naneng-combphy.c
@@ -809,6 +809,27 @@ static int rk3588_combphy_cfg(struct rockchip_combphy_priv *priv)
 		return -EINVAL;
 	}
 
+	if (device_property_read_bool(priv->dev, "rockchip,ext-refclk")) {
+		param_write(priv->phy_grf, &cfg->pipe_clk_ext, true);
+		if (priv->mode == PHY_TYPE_PCIE && rate == 100000000) {
+			val = 0x10;
+			writel(val, priv->mmio + (0x20 << 2));
+
+			val = 0x0c;
+			writel(val, priv->mmio + (0x1b << 2));
+
+			/* Set up su_trim:  */
+			val = 0xf0;
+			writel(val, priv->mmio + (0xa << 2));
+			val = 0x45;
+			writel(val, priv->mmio + (0xb << 2));
+			val = 0xb8;
+			writel(val, priv->mmio + (0xc << 2));
+			val = 0x59;
+			writel(val, priv->mmio + (0xd << 2));
+		}
+	}
+
 	return 0;
 }