[PATCH net-next] net: dsa: mt7530: add support for changing DSA master

[arinc9.unal@gmail.com]

From: Richard van Schagen <richard@routerhints.com>

Add support for changing the master of a port on the MT7530 DSA subdriver.

[ arinc.unal@arinc9.com: Wrote subject and changelog ]

Tested-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Signed-off-by: Richard van Schagen <richard@routerhints.com>
Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
---
 drivers/net/dsa/mt7530.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index b5ad4b4fc00c..04bb4986454e 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -1072,6 +1072,38 @@ mt7530_port_disable(struct dsa_switch *ds, int port)
 	mutex_unlock(&priv->reg_mutex);
 }
 
+static int
+mt7530_port_change_master(struct dsa_switch *ds, int port,
+				       struct net_device *master,
+				       struct netlink_ext_ack *extack)
+{
+	struct mt7530_priv *priv = ds->priv;
+	struct dsa_port *dp = dsa_to_port(ds, port);
+	struct dsa_port *cpu_dp = master->dsa_ptr;
+	int old_cpu = dp->cpu_dp->index;
+	int new_cpu = cpu_dp->index;
+
+	mutex_lock(&priv->reg_mutex);
+
+	/* Move old to new cpu on User port */
+	priv->ports[port].pm &= ~PCR_MATRIX(BIT(old_cpu));
+	priv->ports[port].pm |= PCR_MATRIX(BIT(new_cpu));
+
+	mt7530_rmw(priv, MT7530_PCR_P(port), PCR_MATRIX_MASK,
+		   priv->ports[port].pm);
+
+	/* Move user port from old cpu to new cpu */
+	priv->ports[old_cpu].pm &= ~PCR_MATRIX(BIT(port));
+	priv->ports[new_cpu].pm |= PCR_MATRIX(BIT(port));
+
+	mt7530_write(priv, MT7530_PCR_P(old_cpu), priv->ports[old_cpu].pm);
+	mt7530_write(priv, MT7530_PCR_P(new_cpu), priv->ports[new_cpu].pm);
+
+	mutex_unlock(&priv->reg_mutex);
+
+	return 0;
+}
+
 static int
 mt7530_port_change_mtu(struct dsa_switch *ds, int port, int new_mtu)
 {
@@ -3157,6 +3189,7 @@ static const struct dsa_switch_ops mt7530_switch_ops = {
 	.set_ageing_time	= mt7530_set_ageing_time,
 	.port_enable		= mt7530_port_enable,
 	.port_disable		= mt7530_port_disable,
+	.port_change_master	= mt7530_port_change_master,
 	.port_change_mtu	= mt7530_port_change_mtu,
 	.port_max_mtu		= mt7530_port_max_mtu,
 	.port_stp_state_set	= mt7530_stp_state_set,
-- 
2.37.2