net: dsa: sja1105: Fix broken fixed-link interfaces on user ports

PHYLIB and PHYLINK handle fixed-link interfaces differently. PHYLIB
wraps them in a software PHY ("pseudo fixed link") phydev construct such
that .adjust_link driver callbacks see an unified API. Whereas PHYLINK
simply creates a phylink_link_state structure and passes it to
.mac_config.

At the time the driver was introduced, DSA was using PHYLIB for the
CPU/cascade ports (the ones with no net devices) and PHYLINK for
everything else.

As explained below:

commit aab9c406
Author: Florian Fainelli <f.fainelli@gmail.com>
Date:   Thu May 10 13:17:36 2018 -0700

  net: dsa: Plug in PHYLINK support

  Drivers that utilize fixed links for user-facing ports (e.g: bcm_sf2)
  will need to implement phylink_mac_ops from now on to preserve
  functionality, since PHYLINK *does not* create a phy_device instance
  for fixed links.

In the above patch, DSA guards the .phylink_mac_config callback against
a NULL phydev pointer.  Therefore, .adjust_link is not called in case of
a fixed-link user port.

This patch fixes the situation by converting the driver from using
.adjust_link to .phylink_mac_config.  This can be done now in a unified
fashion for both slave and CPU/cascade ports because DSA now uses
PHYLINK for all ports.
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/sja1105/sja1105_main.c

@@ -734,15 +734,16 @@ static int sja1105_adjust_port_config(struct sja1105_private *priv, int port,
 	return sja1105_clocking_setup_port(priv, port);
 }
 
-static void sja1105_adjust_link(struct dsa_switch *ds, int port,
-				struct phy_device *phydev)
+static void sja1105_mac_config(struct dsa_switch *ds, int port,
+			       unsigned int link_an_mode,
+			       const struct phylink_link_state *state)
 {
 	struct sja1105_private *priv = ds->priv;
 
-	if (!phydev->link)
+	if (!state->link)
 		sja1105_adjust_port_config(priv, port, 0, false);
 	else
-		sja1105_adjust_port_config(priv, port, phydev->speed, true);
+		sja1105_adjust_port_config(priv, port, state->speed, true);
 }
 
 static void sja1105_phylink_validate(struct dsa_switch *ds, int port,
@@ -1515,9 +1516,9 @@ static int sja1105_set_ageing_time(struct dsa_switch *ds,
 static const struct dsa_switch_ops sja1105_switch_ops = {
 	.get_tag_protocol	= sja1105_get_tag_protocol,
 	.setup			= sja1105_setup,
-	.adjust_link		= sja1105_adjust_link,
 	.set_ageing_time	= sja1105_set_ageing_time,
 	.phylink_validate	= sja1105_phylink_validate,
+	.phylink_mac_config	= sja1105_mac_config,
 	.get_strings		= sja1105_get_strings,
 	.get_ethtool_stats	= sja1105_get_ethtool_stats,
 	.get_sset_count		= sja1105_get_sset_count,