net: dsa: rtl8366rb: Switch to phylink

This switches the RTL8366RB over to using phylink callbacks
instead of .adjust_link(). This is a pretty template
switchover. All we adjust is the CPU port so that is why
the code only inspects this port.

We enhance by adding proper error messages, also disabling
the CPU port on the way down and moving dev_info() to
dev_dbg().
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/rtl8366rb.c

@@ -969,8 +969,10 @@ static enum dsa_tag_protocol rtl8366_get_tag_protocol(struct dsa_switch *ds,
 	return DSA_TAG_PROTO_RTL4_A;
 }
 
-static void rtl8366rb_adjust_link(struct dsa_switch *ds, int port,
-				  struct phy_device *phydev)
+static void
+rtl8366rb_mac_link_up(struct dsa_switch *ds, int port, unsigned int mode,
+		      phy_interface_t interface, struct phy_device *phydev,
+		      int speed, int duplex, bool tx_pause, bool rx_pause)
 {
 	struct realtek_smi *smi = ds->priv;
 	int ret;
@@ -978,25 +980,52 @@ static void rtl8366rb_adjust_link(struct dsa_switch *ds, int port,
 	if (port != smi->cpu_port)
 		return;
 
-	dev_info(smi->dev, "adjust link on CPU port (%d)\n", port);
+	dev_dbg(smi->dev, "MAC link up on CPU port (%d)\n", port);
 
 	/* Force the fixed CPU port into 1Gbit mode, no autonegotiation */
 	ret = regmap_update_bits(smi->map, RTL8366RB_MAC_FORCE_CTRL_REG,
 				 BIT(port), BIT(port));
-	if (ret)
+	if (ret) {
+		dev_err(smi->dev, "failed to force 1Gbit on CPU port\n");
 		return;
+	}
 
 	ret = regmap_update_bits(smi->map, RTL8366RB_PAACR2,
 				 0xFF00U,
 				 RTL8366RB_PAACR_CPU_PORT << 8);
-	if (ret)
+	if (ret) {
+		dev_err(smi->dev, "failed to set PAACR on CPU port\n");
 		return;
+	}
 
 	/* Enable the CPU port */
 	ret = regmap_update_bits(smi->map, RTL8366RB_PECR, BIT(port),
 				 0);
-	if (ret)
+	if (ret) {
+		dev_err(smi->dev, "failed to enable the CPU port\n");
+		return;
+	}
+}
+
+static void
+rtl8366rb_mac_link_down(struct dsa_switch *ds, int port, unsigned int mode,
+			phy_interface_t interface)
+{
+	struct realtek_smi *smi = ds->priv;
+	int ret;
+
+	if (port != smi->cpu_port)
 		return;
+
+	dev_dbg(smi->dev, "MAC link down on CPU port (%d)\n", port);
+
+	/* Disable the CPU port */
+	ret = regmap_update_bits(smi->map, RTL8366RB_PECR, BIT(port),
+				 BIT(port));
+	if (ret) {
+		dev_err(smi->dev, "failed to disable the CPU port\n");
+		return;
+	}
 }
 
 static void rb8366rb_set_port_led(struct realtek_smi *smi,
@@ -1439,7 +1468,8 @@ static int rtl8366rb_detect(struct realtek_smi *smi)
 static const struct dsa_switch_ops rtl8366rb_switch_ops = {
 	.get_tag_protocol = rtl8366_get_tag_protocol,
 	.setup = rtl8366rb_setup,
-	.adjust_link = rtl8366rb_adjust_link,
+	.phylink_mac_link_up = rtl8366rb_mac_link_up,
+	.phylink_mac_link_down = rtl8366rb_mac_link_down,
 	.get_strings = rtl8366_get_strings,
 	.get_ethtool_stats = rtl8366_get_ethtool_stats,
 	.get_sset_count = rtl8366_get_sset_count,