net: stmmac: replace stmmac_mdio_busy_wait by readl_poll_timeout

The stmmac_mdio_busy_wait() function do the same job than
readl_poll_timeout().
So is is better to replace it.
Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Acked-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -21,6 +21,7 @@
 *******************************************************************************/
 
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/mii.h>
 #include <linux/of.h>
 #include <linux/of_gpio.h>
@@ -38,22 +39,6 @@
 #define MII_GMAC4_WRITE			(1 << MII_GMAC4_GOC_SHIFT)
 #define MII_GMAC4_READ			(3 << MII_GMAC4_GOC_SHIFT)
 
-static int stmmac_mdio_busy_wait(void __iomem *ioaddr, unsigned int mii_addr)
-{
-	unsigned long curr;
-	unsigned long finish = jiffies + 3 * HZ;
-
-	do {
-		curr = jiffies;
-		if (readl(ioaddr + mii_addr) & MII_BUSY)
-			cpu_relax();
-		else
-			return 0;
-	} while (!time_after_eq(curr, finish));
-
-	return -EBUSY;
-}
-
 /**
  * stmmac_mdio_read
  * @bus: points to the mii_bus structure
@@ -70,7 +55,7 @@ static int stmmac_mdio_read(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;
-
+	u32 v;
 	int data;
 	u32 value = MII_BUSY;
 
@@ -82,12 +67,14 @@ static int stmmac_mdio_read(struct mii_bus *bus, int phyaddr, int phyreg)
 	if (priv->plat->has_gmac4)
 		value |= MII_GMAC4_READ;
 
-	if (stmmac_mdio_busy_wait(priv->ioaddr, mii_address))
+	if (readl_poll_timeout(priv->ioaddr + mii_address, v, !(v & MII_BUSY),
+			       100, 10000))
 		return -EBUSY;
 
 	writel(value, priv->ioaddr + mii_address);
 
-	if (stmmac_mdio_busy_wait(priv->ioaddr, mii_address))
+	if (readl_poll_timeout(priv->ioaddr + mii_address, v, !(v & MII_BUSY),
+			       100, 10000))
 		return -EBUSY;
 
 	/* Read the data from the MII data register */
@@ -111,7 +98,7 @@ 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;
-
+	u32 v;
 	u32 value = MII_BUSY;
 
 	value |= (phyaddr << priv->hw->mii.addr_shift)
@@ -126,7 +113,8 @@ static int stmmac_mdio_write(struct mii_bus *bus, int phyaddr, int phyreg,
 		value |= MII_WRITE;
 
 	/* Wait until any existing MII operation is complete */
-	if (stmmac_mdio_busy_wait(priv->ioaddr, mii_address))
+	if (readl_poll_timeout(priv->ioaddr + mii_address, v, !(v & MII_BUSY),
+			       100, 10000))
 		return -EBUSY;
 
 	/* Set the MII address register to write */
@@ -134,7 +122,8 @@ static int stmmac_mdio_write(struct mii_bus *bus, int phyaddr, int phyreg,
 	writel(value, priv->ioaddr + mii_address);
 
 	/* Wait until any existing MII operation is complete */
-	return stmmac_mdio_busy_wait(priv->ioaddr, mii_address);
+	return readl_poll_timeout(priv->ioaddr + mii_address, v, !(v & MII_BUSY),
+				  100, 10000);
 }
 
 /**