net: bcmgenet: Patch PHY interface for dedicated PHY driver

When we are using a dedicated PHY driver (not the Generic PHY driver)
chances are that it is going to configure RGMII delays and do that in a
way that is incompatible with our incorrect interpretation of the
phy_interface value.

Add a quirk in order to reverse the PHY_INTERFACE_MODE_RGMII to the
value of PHY_INTERFACE_MODE_RGMII_ID such that the MAC continues to be
configured the way it used to be, but the PHY driver can account for
adding delays. Conversely when PHY_INTERFACE_MODE_RGMII_TXID is
specified, return PHY_INTERFACE_MODE_RGMII_RXID to the PHY since we will
have enabled a TXC MAC delay (id_mode_dis=0, meaning there is a delay
inserted).

This is not considered a bug fix at this point since it only affects
Broadcom STB platforms shipping with a Device Tree blob that is not
updatable in the field (quite a few devices out there) and which was
generated using the scripted Device Tree environment shipped with those
platforms' SDK.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c
index 89d16c5..2d29de9 100644 (file)
--- a/drivers/net/ethernet/broadcom/genet/bcmmii.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c
@@ -286,6 +286,7 @@ int bcmgenet_mii_probe(struct net_device *dev)
        struct bcmgenet_priv *priv = netdev_priv(dev);
        struct device *kdev = &priv->pdev->dev;
        struct device_node *dn = kdev->of_node;
+       phy_interface_t phy_iface = priv->phy_interface;
        struct phy_device *phydev;
        u32 phy_flags = 0;
        int ret;
@@ -300,9 +301,42 @@ int bcmgenet_mii_probe(struct net_device *dev)
        priv->old_duplex = -1;
        priv->old_pause = -1;
 
+       /* This is an ugly quirk but we have not been correctly interpreting
+        * the phy_interface values and we have done that across different
+        * drivers, so at least we are consistent in our mistakes.
+        *
+        * When the Generic PHY driver is in use either the PHY has been
+        * strapped or programmed correctly by the boot loader so we should
+        * stick to our incorrect interpretation since we have validated it.
+        *
+        * Now when a dedicated PHY driver is in use, we need to reverse the
+        * meaning of the phy_interface_mode values to something that the PHY
+        * driver will interpret and act on such that we have two mistakes
+        * canceling themselves so to speak. We only do this for the two
+        * modes that GENET driver officially supports on Broadcom STB chips:
+        * PHY_INTERFACE_MODE_RGMII and PHY_INTERFACE_MODE_RGMII_TXID. Other
+        * modes are not *officially* supported with the boot loader and the
+        * scripted environment generating Device Tree blobs for those
+        * platforms.
+        *
+        * Note that internal PHY, MoCA and fixed-link configurations are not
+        * affected because they use different phy_interface_t values or the
+        * Generic PHY driver.
+        */
+       switch (priv->phy_interface) {
+       case PHY_INTERFACE_MODE_RGMII:
+               phy_iface = PHY_INTERFACE_MODE_RGMII_ID;
+               break;
+       case PHY_INTERFACE_MODE_RGMII_TXID:
+               phy_iface = PHY_INTERFACE_MODE_RGMII_RXID;
+               break;
+       default:
+               break;
+       }
+
        if (dn) {
                phydev = of_phy_connect(dev, priv->phy_dn, bcmgenet_mii_setup,
-                                       phy_flags, priv->phy_interface);
+                                       phy_flags, phy_iface);
                if (!phydev) {
                        pr_err("could not attach to PHY\n");
                        return -ENODEV;
@@ -332,7 +366,7 @@ int bcmgenet_mii_probe(struct net_device *dev)
                phydev->dev_flags = phy_flags;
 
                ret = phy_connect_direct(dev, phydev, bcmgenet_mii_setup,
-                                        priv->phy_interface);
+                                        phy_iface);
                if (ret) {
                        pr_err("could not attach to PHY\n");
                        return -ENODEV;