net/ftgmac100: Expose pause frames support and add comment about RGMII

Expose to the phydev that we support Pause frame and add a comment mentioning how we handle RGMII clock delays via u-boot.

Signed-off-by Benjamin Herrenschmidt <[email protected]>

---

This is the diff between v3 that was merged and v4 that I posted shortly afterward.

 drivers/net/ethernet/faraday/ftgmac100.c | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

drivers/net/ethernet/faraday/ftgmac100.c +23 -3

index d42489c..5fe2827 100644
@@ -111,8 +111,8 @@ struct ftgmac100 {
        bool rx_pause;
        bool aneg_pause;
 
-       uint32_t rxdes0_edorr_mask;
-       uint32_t txdes0_edotr_mask;
+       u32 rxdes0_edorr_mask;
+       u32 txdes0_edotr_mask;
 };
 
 static int ftgmac100_alloc_rx_buf(struct ftgmac100 *priv,

@@ -1390,6 +1390,12 @@ static int ftgmac100_mii_probe(struct ftgmac100 *priv, phy_interface_t intf)
                return PTR_ERR(phydev);
        }
 
+       /*
+        * Indicate that we support PAUSE frames (see comment in
+        * Documentation/networking/phy.txt as of v4.10
+        */
+       phydev->supported |= SUPPORTED_Pause | SUPPORTED_Asym_Pause;
+
        phydev->advertising = phydev->supported;
        phy_attached_info(phydev);
 

@@ -1490,6 +1496,21 @@ static int ftgmac100_setup_mdio(struct net_device *ndev)
                iowrite32(reg, priv->base + FTGMAC100_OFFSET_REVR);
        }
 
+       /*
+        * Note: When using RGMII mode, we simply pass "RGMII" to the
+        *       PHY and assume that u-boot will have configured the
+        *       clock delays appropriately for the system.
+        *
+        *       The implementation of the MAC in the Aspeed chips
+        *       supports sub-ns programable delays that need to be
+        *       configured in the SCU while the MAC IP block is in
+        *       reset.
+        *
+        *       If needed in the future, we can support configuring this
+        *       here based on device-tree properties but unless absolutely
+        *       needed I'd rather avoid poking at the SCU registers from
+        *       this driver.
+        */
        if (np)
                intf_prop = of_get_property(np, "phy-interface", NULL);
        if (intf_prop) {
--

2.9.