net: stmmac: add clocks management for gmac driver

This patch intends to add clocks management for stmmac driver:

If CONFIG_PM enabled:
1. Keep clocks disabled after driver probed.
2. Enable clocks when up the net device, and disable clocks when down
the net device.

If CONFIG_PM disabled:
Keep clocks always enabled after driver probed.

Note:
1. It is fine for ethtool, since the way of implementing ethtool_ops::begin
in stmmac is only can be accessed when interface is enabled, so the clocks
are ticked.
2. The MDIO bus has a different life cycle to the MAC, need ensure
clocks are enabled when _mdio_read/write() need clocks, because these
functions can be called while the interface it not opened.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 85 insertions, 26 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
index d64116e0543e..b750074f8f9c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
@@ -15,6 +15,7 @@
 #include <linux/iopoll.h>
 #include <linux/mii.h>
 #include <linux/of_mdio.h>
+#include <linux/pm_runtime.h>
 #include <linux/phy.h>
 #include <linux/property.h>
 #include <linux/slab.h>
@@ -87,21 +88,29 @@ static int stmmac_xgmac2_mdio_read(struct mii_bus *bus, int phyaddr, int phyreg)
 	u32 tmp, addr, value = MII_XGMAC_BUSY;
 	int ret;
 
+	ret = pm_runtime_get_sync(priv->device);
+	if (ret < 0) {
+		pm_runtime_put_noidle(priv->device);
+		return ret;
+	}
+
 	/* Wait until any existing MII operation is complete */
 	if (readl_poll_timeout(priv->ioaddr + mii_data, tmp,
-			       !(tmp & MII_XGMAC_BUSY), 100, 10000))
-		return -EBUSY;
+			       !(tmp & MII_XGMAC_BUSY), 100, 10000)) {
+		ret = -EBUSY;
+		goto err_disable_clks;
+	}
 
 	if (phyreg & MII_ADDR_C45) {
 		phyreg &= ~MII_ADDR_C45;
 
 		ret = stmmac_xgmac2_c45_format(priv, phyaddr, phyreg, &addr);
 		if (ret)
-			return ret;
+			goto err_disable_clks;
 	} else {
 		ret = stmmac_xgmac2_c22_format(priv, phyaddr, phyreg, &addr);
 		if (ret)
-			return ret;
+			goto err_disable_clks;
 
 		value |= MII_XGMAC_SADDR;
 	}
@@ -112,8 +121,10 @@ static int stmmac_xgmac2_mdio_read(struct mii_bus *bus, int phyaddr, int phyreg)
 
 	/* Wait until any existing MII operation is complete */
 	if (readl_poll_timeout(priv->ioaddr + mii_data, tmp,
-			       !(tmp & MII_XGMAC_BUSY), 100, 10000))
-		return -EBUSY;
+			       !(tmp & MII_XGMAC_BUSY), 100, 10000)) {
+		ret = -EBUSY;
+		goto err_disable_clks;
+	}
 
 	/* Set the MII address register to read */
 	writel(addr, priv->ioaddr + mii_address);
@@ -121,11 +132,18 @@ static int stmmac_xgmac2_mdio_read(struct mii_bus *bus, int phyaddr, int phyreg)
 
 	/* Wait until any existing MII operation is complete */
 	if (readl_poll_timeout(priv->ioaddr + mii_data, tmp,
-			       !(tmp & MII_XGMAC_BUSY), 100, 10000))
-		return -EBUSY;
+			       !(tmp & MII_XGMAC_BUSY), 100, 10000)) {
+		ret = -EBUSY;
+		goto err_disable_clks;
+	}
 
 	/* Read the data from the MII data register */
-	return readl(priv->ioaddr + mii_data) & GENMASK(15, 0);
+	ret = (int)readl(priv->ioaddr + mii_data) & GENMASK(15, 0);
+
+err_disable_clks:
+	pm_runtime_put(priv->device);
+
+	return ret;
 }
 
 static int stmmac_xgmac2_mdio_write(struct mii_bus *bus, int phyaddr,
@@ -138,21 +156,29 @@ static int stmmac_xgmac2_mdio_write(struct mii_bus *bus, int phyaddr,
 	u32 addr, tmp, value = MII_XGMAC_BUSY;
 	int ret;
 
+	ret = pm_runtime_get_sync(priv->device);
+	if (ret < 0) {
+		pm_runtime_put_noidle(priv->device);
+		return ret;
+	}
+
 	/* Wait until any existing MII operation is complete */
 	if (readl_poll_timeout(priv->ioaddr + mii_data, tmp,
-			       !(tmp & MII_XGMAC_BUSY), 100, 10000))
-		return -EBUSY;
+			       !(tmp & MII_XGMAC_BUSY), 100, 10000)) {
+		ret = -EBUSY;
+		goto err_disable_clks;
+	}
 
 	if (phyreg & MII_ADDR_C45) {
 		phyreg &= ~MII_ADDR_C45;
 
 		ret = stmmac_xgmac2_c45_format(priv, phyaddr, phyreg, &addr);
 		if (ret)
-			return ret;
+			goto err_disable_clks;
 	} else {
 		ret = stmmac_xgmac2_c22_format(priv, phyaddr, phyreg, &addr);
 		if (ret)
-			return ret;
+			goto err_disable_clks;
 
 		value |= MII_XGMAC_SADDR;
 	}
@@ -164,16 +190,23 @@ static int stmmac_xgmac2_mdio_write(struct mii_bus *bus, int phyaddr,
 
 	/* Wait until any existing MII operation is complete */
 	if (readl_poll_timeout(priv->ioaddr + mii_data, tmp,
-			       !(tmp & MII_XGMAC_BUSY), 100, 10000))
-		return -EBUSY;
+			       !(tmp & MII_XGMAC_BUSY), 100, 10000)) {
+		ret = -EBUSY;
+		goto err_disable_clks;
+	}
 
 	/* Set the MII address register to write */
 	writel(addr, priv->ioaddr + mii_address);
 	writel(value, priv->ioaddr + mii_data);
 
 	/* Wait until any existing MII operation is complete */
-	return readl_poll_timeout(priv->ioaddr + mii_data, tmp,
-				  !(tmp & MII_XGMAC_BUSY), 100, 10000);
+	ret = readl_poll_timeout(priv->ioaddr + mii_data, tmp,
+				 !(tmp & MII_XGMAC_BUSY), 100, 10000);
+
+err_disable_clks:
+	pm_runtime_put(priv->device);
+
+	return ret;
 }
 
 /**
@@ -196,6 +229,12 @@ static int stmmac_mdio_read(struct mii_bus *bus, int phyaddr, int phyreg)
 	int data = 0;
 	u32 v;
 
+	data = pm_runtime_get_sync(priv->device);
+	if (data < 0) {
+		pm_runtime_put_noidle(priv->device);
+		return data;
+	}
+
 	value |= (phyaddr << priv->hw->mii.addr_shift)
 		& priv->hw->mii.addr_mask;
 	value |= (phyreg << priv->hw->mii.reg_shift) & priv->hw->mii.reg_mask;
@@ -216,19 +255,26 @@ static int stmmac_mdio_read(struct mii_bus *bus, int phyaddr, int phyreg)
 	}
 
 	if (readl_poll_timeout(priv->ioaddr + mii_address, v, !(v & MII_BUSY),
-			       100, 10000))
-		return -EBUSY;
+			       100, 10000)) {
+		data = -EBUSY;
+		goto err_disable_clks;
+	}
 
 	writel(data, priv->ioaddr + mii_data);
 	writel(value, priv->ioaddr + mii_address);
 
 	if (readl_poll_timeout(priv->ioaddr + mii_address, v, !(v & MII_BUSY),
-			       100, 10000))
-		return -EBUSY;
+			       100, 10000)) {
+		data = -EBUSY;
+		goto err_disable_clks;
+	}
 
 	/* Read the data from the MII data register */
 	data = (int)readl(priv->ioaddr + mii_data) & MII_DATA_MASK;
 
+err_disable_clks:
+	pm_runtime_put(priv->device);
+
 	return data;
 }
 
@@ -247,10 +293,16 @@ static int stmmac_mdio_write(struct mii_bus *bus, int phyaddr, int phyreg,
 	struct stmmac_priv *priv = netdev_priv(ndev);
 	unsigned int mii_address = priv->hw->mii.addr;
 	unsigned int mii_data = priv->hw->mii.data;
+	int ret, data = phydata;
 	u32 value = MII_BUSY;
-	int data = phydata;
 	u32 v;
 
+	ret = pm_runtime_get_sync(priv->device);
+	if (ret < 0) {
+		pm_runtime_put_noidle(priv->device);
+		return ret;
+	}
+
 	value |= (phyaddr << priv->hw->mii.addr_shift)
 		& priv->hw->mii.addr_mask;
 	value |= (phyreg << priv->hw->mii.reg_shift) & priv->hw->mii.reg_mask;
@@ -275,16 +327,23 @@ static int stmmac_mdio_write(struct mii_bus *bus, int phyaddr, int phyreg,
 
 	/* Wait until any existing MII operation is complete */
 	if (readl_poll_timeout(priv->ioaddr + mii_address, v, !(v & MII_BUSY),
-			       100, 10000))
-		return -EBUSY;
+			       100, 10000)) {
+		ret = -EBUSY;
+		goto err_disable_clks;
+	}
 
 	/* Set the MII address register to write */
 	writel(data, priv->ioaddr + mii_data);
 	writel(value, priv->ioaddr + mii_address);
 
 	/* Wait until any existing MII operation is complete */
-	return readl_poll_timeout(priv->ioaddr + mii_address, v, !(v & MII_BUSY),
-				  100, 10000);
+	ret = readl_poll_timeout(priv->ioaddr + mii_address, v, !(v & MII_BUSY),
+				 100, 10000);
+
+err_disable_clks:
+	pm_runtime_put(priv->device);
+
+	return ret;
 }
 
 /**