phylib: mdio: Add sysfs attribute for PHY identifiers.

This adds a phy_id sysfs attribute to MDIO devices, containing the
32-bit PHY identifier reported by the device.  This attribute can
be useful when debugging problems related to phy drivers.  Other
enumerable buses already have similar attributes.

Signed-off-by: Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/Documentation/ABI/testing/sysfs-bus-mdio b/Documentation/ABI/testing/sysfs-bus-mdio
new file mode 100644 (file)
index 0000000..6349749
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-mdio
@@ -0,0 +1,9 @@
+What:          /sys/bus/mdio_bus/devices/.../phy_id
+Date:          November 2012
+KernelVersion: 3.8
+Contact:       netdev@vger.kernel.org
+Description:
+               This attribute contains the 32-bit PHY Identifier as reported
+               by the device during bus enumeration, encoded in hexadecimal.
+               This ID is used to match the device with the appropriate
+               driver.

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index c1ef3000ea6065a9c394ae1fef99e0fa76bd852f..044b5326459fe807fc53e7af30de56c630c5cad3 100644 (file)
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -431,10 +431,24 @@ static struct dev_pm_ops mdio_bus_pm_ops = {
 
 #endif /* CONFIG_PM */
 
+static ssize_t
+phy_id_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+       struct phy_device *phydev = to_phy_device(dev);
+
+       return sprintf(buf, "0x%.8lx\n", (unsigned long)phydev->phy_id);
+}
+
+static struct device_attribute mdio_dev_attrs[] = {
+       __ATTR_RO(phy_id),
+       __ATTR_NULL
+};
+
 struct bus_type mdio_bus_type = {
        .name           = "mdio_bus",
        .match          = mdio_bus_match,
        .pm             = MDIO_BUS_PM_OPS,
+       .dev_attrs      = mdio_dev_attrs,
 };
 EXPORT_SYMBOL(mdio_bus_type);