1 files changed, 101 insertions, 0 deletions
diff --git a/drivers/net/phy/phy-core.c b/drivers/net/phy/phy-core.c
new file mode 100644
index 000000000000..6739b738bbaf
--- /dev/null
+++ b/drivers/net/phy/phy-core.c
@@ -0,0 +1,101 @@
+/*
+ * Core PHY library, taken from phy.c
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+#include <linux/export.h>
+#include <linux/phy.h>
+
+static void mmd_phy_indirect(struct mii_bus *bus, int phy_addr, int devad,
+			     u16 regnum)
+{
+	/* Write the desired MMD Devad */
+	bus->write(bus, phy_addr, MII_MMD_CTRL, devad);
+
+	/* Write the desired MMD register address */
+	bus->write(bus, phy_addr, MII_MMD_DATA, regnum);
+
+	/* Select the Function : DATA with no post increment */
+	bus->write(bus, phy_addr, MII_MMD_CTRL, devad | MII_MMD_CTRL_NOINCR);
+}
+
+/**
+ * phy_read_mmd - Convenience function for reading a register
+ * from an MMD on a given PHY.
+ * @phydev: The phy_device struct
+ * @devad: The MMD to read from (0..31)
+ * @regnum: The register on the MMD to read (0..65535)
+ *
+ * Same rules as for phy_read();
+ */
+int phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum)
+{
+	int val;
+
+	if (regnum > (u16)~0 || devad > 32)
+		return -EINVAL;
+
+	if (phydev->drv->read_mmd) {
+		val = phydev->drv->read_mmd(phydev, devad, regnum);
+	} else if (phydev->is_c45) {
+		u32 addr = MII_ADDR_C45 | (devad << 16) | (regnum & 0xffff);
+
+		val = mdiobus_read(phydev->mdio.bus, phydev->mdio.addr, addr);
+	} else {
+		struct mii_bus *bus = phydev->mdio.bus;
+		int phy_addr = phydev->mdio.addr;
+
+		mutex_lock(&bus->mdio_lock);
+		mmd_phy_indirect(bus, phy_addr, devad, regnum);
+
+		/* Read the content of the MMD's selected register */
+		val = bus->read(bus, phy_addr, MII_MMD_DATA);
+		mutex_unlock(&bus->mdio_lock);
+	}
+	return val;
+}
+EXPORT_SYMBOL(phy_read_mmd);
+
+/**
+ * phy_write_mmd - Convenience function for writing a register
+ * on an MMD on a given PHY.
+ * @phydev: The phy_device struct
+ * @devad: The MMD to read from
+ * @regnum: The register on the MMD to read
+ * @val: value to write to @regnum
+ *
+ * Same rules as for phy_write();
+ */
+int phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val)
+{
+	int ret;
+
+	if (regnum > (u16)~0 || devad > 32)
+		return -EINVAL;
+
+	if (phydev->drv->write_mmd) {
+		ret = phydev->drv->write_mmd(phydev, devad, regnum, val);
+	} else if (phydev->is_c45) {
+		u32 addr = MII_ADDR_C45 | (devad << 16) | (regnum & 0xffff);
+
+		ret = mdiobus_write(phydev->mdio.bus, phydev->mdio.addr,
+				    addr, val);
+	} else {
+		struct mii_bus *bus = phydev->mdio.bus;
+		int phy_addr = phydev->mdio.addr;
+
+		mutex_lock(&bus->mdio_lock);
+		mmd_phy_indirect(bus, phy_addr, devad, regnum);
+
+		/* Write the data into MMD's selected register */
+		bus->write(bus, phy_addr, MII_MMD_DATA, val);
+		mutex_unlock(&bus->mdio_lock);
+
+		ret = 0;
+	}
+	return ret;
+}
+EXPORT_SYMBOL(phy_write_mmd);