dsa: mv88e6xxx: Allow speed/duplex of port to be configured

The current code sets user ports to perform auto negotiation using the
phy. CPU and DSA ports are configured to full duplex and maximum speed
the switch supports.

There are however use cases where the CPU has a slower port, and when
user ports have SFP modules with fixed speed. In these cases, port
settings to be read from a fixed_phy devices. The switch driver then
needs to implement the adjust_link op, so the port settings can be
set.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6123_61_65.c

@@ -129,6 +129,7 @@ struct dsa_switch_driver mv88e6123_61_65_switch_driver = {
 	.get_strings		= mv88e6xxx_get_strings,
 	.get_ethtool_stats	= mv88e6xxx_get_ethtool_stats,
 	.get_sset_count		= mv88e6xxx_get_sset_count,
+	.adjust_link		= mv88e6xxx_adjust_link,
 #ifdef CONFIG_NET_DSA_HWMON
 	.get_temp		= mv88e6xxx_get_temp,
 #endif

drivers/net/dsa/mv88e6131.c

@@ -182,6 +182,7 @@ struct dsa_switch_driver mv88e6131_switch_driver = {
 	.get_strings		= mv88e6xxx_get_strings,
 	.get_ethtool_stats	= mv88e6xxx_get_ethtool_stats,
 	.get_sset_count		= mv88e6xxx_get_sset_count,
+	.adjust_link		= mv88e6xxx_adjust_link,
 };
 
 MODULE_ALIAS("platform:mv88e6085");

drivers/net/dsa/mv88e6171.c

@@ -108,6 +108,7 @@ struct dsa_switch_driver mv88e6171_switch_driver = {
 	.get_strings		= mv88e6xxx_get_strings,
 	.get_ethtool_stats	= mv88e6xxx_get_ethtool_stats,
 	.get_sset_count		= mv88e6xxx_get_sset_count,
+	.adjust_link		= mv88e6xxx_adjust_link,
 #ifdef CONFIG_NET_DSA_HWMON
 	.get_temp               = mv88e6xxx_get_temp,
 #endif

drivers/net/dsa/mv88e6352.c

@@ -328,6 +328,7 @@ struct dsa_switch_driver mv88e6352_switch_driver = {
 	.get_strings		= mv88e6xxx_get_strings,
 	.get_ethtool_stats	= mv88e6xxx_get_ethtool_stats,
 	.get_sset_count		= mv88e6xxx_get_sset_count,
+	.adjust_link		= mv88e6xxx_adjust_link,
 	.set_eee		= mv88e6xxx_set_eee,
 	.get_eee		= mv88e6xxx_get_eee,
 #ifdef CONFIG_NET_DSA_HWMON

drivers/net/dsa/mv88e6xxx.c

@@ -14,6 +14,7 @@
 #include <linux/debugfs.h>
 #include <linux/delay.h>
 #include <linux/etherdevice.h>
+#include <linux/ethtool.h>
 #include <linux/if_bridge.h>
 #include <linux/jiffies.h>
 #include <linux/list.h>
@@ -560,6 +561,63 @@ static bool mv88e6xxx_6352_family(struct dsa_switch *ds)
 	return false;
 }
 
+/* We expect the switch to perform auto negotiation if there is a real
+ * phy. However, in the case of a fixed link phy, we force the port
+ * settings from the fixed link settings.
+ */
+void mv88e6xxx_adjust_link(struct dsa_switch *ds, int port,
+			   struct phy_device *phydev)
+{
+	struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
+	u32 ret, reg;
+
+	if (!phy_is_pseudo_fixed_link(phydev))
+		return;
+
+	mutex_lock(&ps->smi_mutex);
+
+	ret = _mv88e6xxx_reg_read(ds, REG_PORT(port), PORT_PCS_CTRL);
+	if (ret < 0)
+		goto out;
+
+	reg = ret & ~(PORT_PCS_CTRL_LINK_UP |
+		      PORT_PCS_CTRL_FORCE_LINK |
+		      PORT_PCS_CTRL_DUPLEX_FULL |
+		      PORT_PCS_CTRL_FORCE_DUPLEX |
+		      PORT_PCS_CTRL_UNFORCED);
+
+	reg |= PORT_PCS_CTRL_FORCE_LINK;
+	if (phydev->link)
+			reg |= PORT_PCS_CTRL_LINK_UP;
+
+	if (mv88e6xxx_6065_family(ds) && phydev->speed > SPEED_100)
+		goto out;
+
+	switch (phydev->speed) {
+	case SPEED_1000:
+		reg |= PORT_PCS_CTRL_1000;
+		break;
+	case SPEED_100:
+		reg |= PORT_PCS_CTRL_100;
+		break;
+	case SPEED_10:
+		reg |= PORT_PCS_CTRL_10;
+		break;
+	default:
+		pr_info("Unknown speed");
+		goto out;
+	}
+
+	reg |= PORT_PCS_CTRL_FORCE_DUPLEX;
+	if (phydev->duplex == DUPLEX_FULL)
+		reg |= PORT_PCS_CTRL_DUPLEX_FULL;
+
+	_mv88e6xxx_reg_write(ds, REG_PORT(port), PORT_PCS_CTRL, reg);
+
+out:
+	mutex_unlock(&ps->smi_mutex);
+}
+
 /* Must be called with SMI mutex held */
 static int _mv88e6xxx_stats_wait(struct dsa_switch *ds)
 {

drivers/net/dsa/mv88e6xxx.h

@@ -446,6 +446,8 @@ void mv88e6xxx_get_ethtool_stats(struct dsa_switch *ds, int port,
 				 uint64_t *data);
 int mv88e6xxx_get_sset_count(struct dsa_switch *ds);
 int mv88e6xxx_get_sset_count_basic(struct dsa_switch *ds);
+void mv88e6xxx_adjust_link(struct dsa_switch *ds, int port,
+			   struct phy_device *phydev);
 int mv88e6xxx_get_regs_len(struct dsa_switch *ds, int port);
 void mv88e6xxx_get_regs(struct dsa_switch *ds, int port,
 			struct ethtool_regs *regs, void *_p);