net/fsl: Add mEMAC MDIO support to XGMAC MDIO

The Freescale mEMAC supports operating at 10/100/1000/10G, and
its associated MDIO controller is likewise capable of operating
both Clause 22 and Clause 45 MDIO buses. It is nearly identical
to the MDIO controller on the XGMAC, so we just modify that
driver.

Portions of this driver developed by:

Sandeep Singh <sandeep@freescale.com>
Roy Zang <tie-fei.zang@freescale.com>
Signed-off-by: Andy Fleming <afleming@gmail.com>
Signed-off-by: Shaohui Xie <Shaohui.Xie@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/Kconfig

@@ -69,7 +69,8 @@ config FSL_XGMAC_MDIO
 	select PHYLIB
 	select OF_MDIO
 	---help---
-	  This driver supports the MDIO bus on the Fman 10G Ethernet MACs.
+	  This driver supports the MDIO bus on the Fman 10G Ethernet MACs, and
+	  on the FMan mEMAC (which supports both Clauses 22 and 45)
 
 config UCC_GETH
 	tristate "Freescale QE Gigabit Ethernet"

drivers/net/ethernet/freescale/xgmac_mdio.c

@@ -32,6 +32,7 @@ struct tgec_mdio_controller {
 	__be32	mdio_addr;	/* MDIO address */
 } __packed;
 
+#define MDIO_STAT_ENC		BIT(6)
 #define MDIO_STAT_CLKDIV(x)	(((x>>1) & 0xff) << 8)
 #define MDIO_STAT_BSY		(1 << 0)
 #define MDIO_STAT_RD_ER		(1 << 1)
@@ -91,19 +92,39 @@ static int xgmac_wait_until_done(struct device *dev,
 static int xgmac_mdio_write(struct mii_bus *bus, int phy_id, int regnum, u16 value)
 {
 	struct tgec_mdio_controller __iomem *regs = bus->priv;
-	uint16_t dev_addr = regnum >> 16;
+	uint16_t dev_addr;
+	u32 mdio_ctl, mdio_stat;
 	int ret;
 
+	mdio_stat = in_be32(&regs->mdio_stat);
+	if (regnum & MII_ADDR_C45) {
+		/* Clause 45 (ie 10G) */
+		dev_addr = (regnum >> 16) & 0x1f;
+		mdio_stat |= MDIO_STAT_ENC;
+	} else {
+		/* Clause 22 (ie 1G) */
+		dev_addr = regnum & 0x1f;
+		mdio_stat &= ~MDIO_STAT_ENC;
+	}
+
+	out_be32(&regs->mdio_stat, mdio_stat);
+
+	ret = xgmac_wait_until_free(&bus->dev, regs);
+	if (ret)
+		return ret;
+
 	/* Set the port and dev addr */
-	out_be32(&regs->mdio_ctl,
-		 MDIO_CTL_PORT_ADDR(phy_id) | MDIO_CTL_DEV_ADDR(dev_addr));
+	mdio_ctl = MDIO_CTL_PORT_ADDR(phy_id) | MDIO_CTL_DEV_ADDR(dev_addr);
+	out_be32(&regs->mdio_ctl, mdio_ctl);
 
 	/* Set the register address */
+	if (regnum & MII_ADDR_C45) {
 		out_be32(&regs->mdio_addr, regnum & 0xffff);
 
 		ret = xgmac_wait_until_free(&bus->dev, regs);
 		if (ret)
 			return ret;
+	}
 
 	/* Write the value to the register */
 	out_be32(&regs->mdio_data, MDIO_DATA(value));
@@ -123,21 +144,39 @@ static int xgmac_mdio_write(struct mii_bus *bus, int phy_id, int regnum, u16 val
 static int xgmac_mdio_read(struct mii_bus *bus, int phy_id, int regnum)
 {
 	struct tgec_mdio_controller __iomem *regs = bus->priv;
-	uint16_t dev_addr = regnum >> 16;
+	uint16_t dev_addr;
+	uint32_t mdio_stat;
 	uint32_t mdio_ctl;
 	uint16_t value;
 	int ret;
 
+	mdio_stat = in_be32(&regs->mdio_stat);
+	if (regnum & MII_ADDR_C45) {
+		dev_addr = (regnum >> 16) & 0x1f;
+		mdio_stat |= MDIO_STAT_ENC;
+	} else {
+		dev_addr = regnum & 0x1f;
+		mdio_stat = ~MDIO_STAT_ENC;
+	}
+
+	out_be32(&regs->mdio_stat, mdio_stat);
+
+	ret = xgmac_wait_until_free(&bus->dev, regs);
+	if (ret)
+		return ret;
+
 	/* Set the Port and Device Addrs */
 	mdio_ctl = MDIO_CTL_PORT_ADDR(phy_id) | MDIO_CTL_DEV_ADDR(dev_addr);
 	out_be32(&regs->mdio_ctl, mdio_ctl);
 
 	/* Set the register address */
+	if (regnum & MII_ADDR_C45) {
 		out_be32(&regs->mdio_addr, regnum & 0xffff);
 
 		ret = xgmac_wait_until_free(&bus->dev, regs);
 		if (ret)
 			return ret;
+	}
 
 	/* Initiate the read */
 	out_be32(&regs->mdio_ctl, mdio_ctl | MDIO_CTL_READ);
@@ -224,6 +263,9 @@ static struct of_device_id xgmac_mdio_match[] = {
 	{
 		.compatible = "fsl,fman-xmdio",
 	},
+	{
+		.compatible = "fsl,fman-memac-mdio",
+	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, xgmac_mdio_match);