phylib: add mdiobus_{read,write}

Add mdiobus_{read,write} routines to allow direct reading/writing
of registers on an mii bus without having to go through the PHY
abstraction, and make phy_{read,write} use these primitives.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 49 insertions, 0 deletions

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index fb4c0965b152..6671e2da0d57 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -211,6 +211,55 @@ struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
 EXPORT_SYMBOL(mdiobus_scan);
 
 /**
+ * mdiobus_read - Convenience function for reading a given MII mgmt register
+ * @bus: the mii_bus struct
+ * @addr: the phy address
+ * @regnum: register number to read
+ *
+ * NOTE: MUST NOT be called from interrupt context,
+ * because the bus read/write functions may wait for an interrupt
+ * to conclude the operation.
+ */
+int mdiobus_read(struct mii_bus *bus, int addr, u16 regnum)
+{
+        int retval;
+
+        BUG_ON(in_interrupt());
+
+        mutex_lock(&bus->mdio_lock);
+        retval = bus->read(bus, addr, regnum);
+        mutex_unlock(&bus->mdio_lock);
+
+        return retval;
+}
+EXPORT_SYMBOL(mdiobus_read);
+
+/**
+ * mdiobus_write - Convenience function for writing a given MII mgmt register
+ * @bus: the mii_bus struct
+ * @addr: the phy address
+ * @regnum: register number to write
+ * @val: value to write to @regnum
+ *
+ * NOTE: MUST NOT be called from interrupt context,
+ * because the bus read/write functions may wait for an interrupt
+ * to conclude the operation.
+ */
+int mdiobus_write(struct mii_bus *bus, int addr, u16 regnum, u16 val)
+{
+        int err;
+
+        BUG_ON(in_interrupt());
+
+        mutex_lock(&bus->mdio_lock);
+        err = bus->write(bus, addr, regnum, val);
+        mutex_unlock(&bus->mdio_lock);
+
+        return err;
+}
+EXPORT_SYMBOL(mdiobus_write);
+
+/**
  * mdio_bus_match - determine if given PHY driver supports the given PHY device
  * @dev: target PHY device
  * @drv: given PHY driver