net: stmmac: disable/enable ptp_ref_clk in suspend/resume flow

disable ptp_ref_clk in suspend flow, and enable it in resume flow.

Fixes: f573c0b9 ("stmmac: move stmmac_clk, pclk, clk_ptp_ref and stmmac_rst to platform structure")
Signed-off-by: Biao Huang <biao.huang@mediatek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -4742,8 +4742,10 @@ int stmmac_suspend(struct device *dev)
 		stmmac_mac_set(priv, priv->ioaddr, false);
 		pinctrl_pm_select_sleep_state(priv->device);
 		/* Disable clock in case of PWM is off */
-		clk_disable(priv->plat->pclk);
-		clk_disable(priv->plat->stmmac_clk);
+		if (priv->plat->clk_ptp_ref)
+			clk_disable_unprepare(priv->plat->clk_ptp_ref);
+		clk_disable_unprepare(priv->plat->pclk);
+		clk_disable_unprepare(priv->plat->stmmac_clk);
 	}
 	mutex_unlock(&priv->lock);
 
@@ -4806,8 +4808,10 @@ int stmmac_resume(struct device *dev)
 	} else {
 		pinctrl_pm_select_default_state(priv->device);
 		/* enable the clk previously disabled */
-		clk_enable(priv->plat->stmmac_clk);
-		clk_enable(priv->plat->pclk);
+		clk_prepare_enable(priv->plat->stmmac_clk);
+		clk_prepare_enable(priv->plat->pclk);
+		if (priv->plat->clk_ptp_ref)
+			clk_prepare_enable(priv->plat->clk_ptp_ref);
 		/* reset the phy so that it's ready */
 		if (priv->mii)
 			stmmac_mdio_reset(priv->mii);