ethtool, mdio, mii: Specify MDIO information fields in struct ethtool_cmd

Add comments for ethtool_cmd::phy_address and
ethtool_cmd::mdio_support, and definitions of the flags currently
used in mdio_support.

In the mdio library, assert that its own flags continue to match those
in the ethtool interface.

In the mii library, use the ethtool flag definition and stop
including <linux/mdio.h>.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 21 insertions, 2 deletions

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index da5b2de99ae4..e1d9e0ede309 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -30,10 +30,15 @@ struct ethtool_cmd {
                                  * access it */
         __u8    duplex;         /* Duplex, half or full */
         __u8    port;           /* Which connector port */
-        __u8    phy_address;
+        __u8    phy_address;    /* MDIO PHY address (PRTAD for clause 45).
+                                 * May be read-only or read-write
+                                 * depending on the driver.
+                                 */
         __u8    transceiver;    /* Which transceiver to use */
         __u8    autoneg;        /* Enable or disable autonegotiation */
-        __u8    mdio_support;
+        __u8    mdio_support;   /* MDIO protocols supported.  Read-only.
+                                 * Not set by all drivers.
+                                 */
         __u32   maxtxpkt;       /* Tx pkts before generating tx int */
         __u32   maxrxpkt;       /* Rx pkts before generating rx int */
         __u16   speed_hi;       /* The forced speed (upper
@@ -59,6 +64,20 @@ static inline __u32 ethtool_cmd_speed(const struct ethtool_cmd *ep)
         return (ep->speed_hi << 16) | ep->speed;
 }
 
+/* Device supports clause 22 register access to PHY or peripherals
+ * using the interface defined in <linux/mii.h>.  This should not be
+ * set if there are known to be no such peripherals present or if
+ * the driver only emulates clause 22 registers for compatibility.
+ */
+#define ETH_MDIO_SUPPORTS_C22   1
+
+/* Device supports clause 45 register access to PHY or peripherals
+ * using the interface defined in <linux/mii.h> and <linux/mdio.h>.
+ * This should not be set if there are known to be no such peripherals
+ * present.
+ */
+#define ETH_MDIO_SUPPORTS_C45   2
+
 #define ETHTOOL_FWVERS_LEN      32
 #define ETHTOOL_BUSINFO_LEN     32
 /* these strings are set to whatever the driver author decides... */