[PATCH 18/20] net: stmmac: Move PTP clock enabling to PTP-init method

[Serge Semin <Sergey.Semin@baikalelectronics.ru>]

That clock is purely dedicated for the PTP feature of DW *MAC. From the
driver readability and maintainability point of the view it's better to
have it enabled/disable in the PTP interface init/release methods. Let's
do that by moving the clock prepare/enable procedure invocation to the
stmmac_init_ptp() method and adding the clock disable/unprepare function
call to stmmac_release_ptp(). Since the clock is now handled in the
framework of the PTP-interface related initializers/de-initializers we
need to call the stmmac_release_ptp() method in the HW-setup antagonist -
stmmac_hw_teardown(). Thus call the later one when the network device is
closed to clean the PTP-interface too.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
---
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 25 +++++++++++++------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index f3ced94b3f4e..d6446aa712e1 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -761,10 +761,18 @@ static int stmmac_hwtstamp_get(struct net_device *dev, struct ifreq *ifr)
 static int stmmac_init_ptp(struct stmmac_priv *priv)
 {
 	bool xmac = priv->plat->has_gmac4 || priv->plat->has_xgmac;
+	int ret;
 
 	if (!(priv->dma_cap.time_stamp || priv->dma_cap.atime_stamp))
 		return -EOPNOTSUPP;
 
+	ret = clk_prepare_enable(priv->plat->clk_ptp_ref);
+	if (ret) {
+		netdev_warn(priv->dev, "failed to enable PTP ref-clock: %d\n",
+			    ret);
+		return ret;
+	}
+
 	priv->adv_ts = 0;
 	/* Check if adv_ts can be enabled for dwmac 4.x / xgmac core */
 	if (xmac && priv->dma_cap.atime_stamp)
@@ -790,8 +798,12 @@ static int stmmac_init_ptp(struct stmmac_priv *priv)
 
 static void stmmac_release_ptp(struct stmmac_priv *priv)
 {
-	clk_disable_unprepare(priv->plat->clk_ptp_ref);
+	if (!(priv->dma_cap.time_stamp || priv->dma_cap.atime_stamp))
+		return;
+
 	stmmac_ptp_unregister(priv);
+
+	clk_disable_unprepare(priv->plat->clk_ptp_ref);
 }
 
 /**
@@ -2716,10 +2728,6 @@ static int stmmac_hw_setup(struct net_device *dev, bool init_ptp)
 	stmmac_mmc_setup(priv);
 
 	if (init_ptp) {
-		ret = clk_prepare_enable(priv->plat->clk_ptp_ref);
-		if (ret < 0)
-			netdev_warn(priv->dev, "failed to enable PTP reference clock: %d\n", ret);
-
 		ret = stmmac_init_ptp(priv);
 		if (ret == -EOPNOTSUPP)
 			netdev_warn(priv->dev, "PTP not supported by HW\n");
@@ -2784,7 +2792,7 @@ static void stmmac_hw_teardown(struct net_device *dev)
 {
 	struct stmmac_priv *priv = netdev_priv(dev);
 
-	clk_disable_unprepare(priv->plat->clk_ptp_ref);
+	stmmac_release_ptp(priv);
 }
 
 /**
@@ -2965,6 +2973,9 @@ static int stmmac_release(struct net_device *dev)
 	/* Stop TX/RX DMA and clear the descriptors */
 	stmmac_stop_all_dma(priv);
 
+	/* Cleanup HW setup */
+	stmmac_hw_teardown(dev);
+
 	/* Release and free the Rx/Tx resources */
 	free_dma_desc_resources(priv);
 
@@ -2973,8 +2984,6 @@ static int stmmac_release(struct net_device *dev)
 
 	netif_carrier_off(dev);
 
-	stmmac_release_ptp(priv);
-
 	return 0;
 }
 
-- 
2.29.2