net: dsa: qca: ar9331: make proper initial port defaults

Make sure that all external port are actually isolated from each other,
so no packets are leaked.

Fixes: ec6698c272 ("net: dsa: add support for Atheros AR9331 built-in switch")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/qca/ar9331.c

@@ -101,6 +101,23 @@
 	 AR9331_SW_PORT_STATUS_RX_FLOW_EN | AR9331_SW_PORT_STATUS_TX_FLOW_EN | \
 	 AR9331_SW_PORT_STATUS_SPEED_M)
 
+#define AR9331_SW_REG_PORT_CTRL(_port)			(0x104 + (_port) * 0x100)
+#define AR9331_SW_PORT_CTRL_HEAD_EN			BIT(11)
+#define AR9331_SW_PORT_CTRL_PORT_STATE			GENMASK(2, 0)
+#define AR9331_SW_PORT_CTRL_PORT_STATE_DISABLED		0
+#define AR9331_SW_PORT_CTRL_PORT_STATE_BLOCKING		1
+#define AR9331_SW_PORT_CTRL_PORT_STATE_LISTENING	2
+#define AR9331_SW_PORT_CTRL_PORT_STATE_LEARNING		3
+#define AR9331_SW_PORT_CTRL_PORT_STATE_FORWARD		4
+
+#define AR9331_SW_REG_PORT_VLAN(_port)			(0x108 + (_port) * 0x100)
+#define AR9331_SW_PORT_VLAN_8021Q_MODE			GENMASK(31, 30)
+#define AR9331_SW_8021Q_MODE_SECURE			3
+#define AR9331_SW_8021Q_MODE_CHECK			2
+#define AR9331_SW_8021Q_MODE_FALLBACK			1
+#define AR9331_SW_8021Q_MODE_NONE			0
+#define AR9331_SW_PORT_VLAN_PORT_VID_MEMBER		GENMASK(25, 16)
+
 /* MIB registers */
 #define AR9331_MIB_COUNTER(x)			(0x20000 + ((x) * 0x100))
 
@@ -371,11 +388,59 @@ static int ar9331_sw_mbus_init(struct ar9331_sw_priv *priv)
 	return 0;
 }
 
+static int ar9331_sw_setup_port(struct dsa_switch *ds, int port)
+{
+	struct ar9331_sw_priv *priv = (struct ar9331_sw_priv *)ds->priv;
+	struct regmap *regmap = priv->regmap;
+	u32 port_mask, port_ctrl, val;
+	int ret;
+
+	/* Generate default port settings */
+	port_ctrl = FIELD_PREP(AR9331_SW_PORT_CTRL_PORT_STATE,
+			       AR9331_SW_PORT_CTRL_PORT_STATE_FORWARD);
+
+	if (dsa_is_cpu_port(ds, port)) {
+		/* CPU port should be allowed to communicate with all user
+		 * ports.
+		 */
+		port_mask = dsa_user_ports(ds);
+		/* Enable Atheros header on CPU port. This will allow us
+		 * communicate with each port separately
+		 */
+		port_ctrl |= AR9331_SW_PORT_CTRL_HEAD_EN;
+	} else if (dsa_is_user_port(ds, port)) {
+		/* User ports should communicate only with the CPU port.
+		 */
+		port_mask = BIT(dsa_upstream_port(ds, port));
+	} else {
+		/* Other ports do not need to communicate at all */
+		port_mask = 0;
+	}
+
+	val = FIELD_PREP(AR9331_SW_PORT_VLAN_8021Q_MODE,
+			 AR9331_SW_8021Q_MODE_NONE) |
+		FIELD_PREP(AR9331_SW_PORT_VLAN_PORT_VID_MEMBER, port_mask);
+
+	ret = regmap_write(regmap, AR9331_SW_REG_PORT_VLAN(port), val);
+	if (ret)
+		goto error;
+
+	ret = regmap_write(regmap, AR9331_SW_REG_PORT_CTRL(port), port_ctrl);
+	if (ret)
+		goto error;
+
+	return 0;
+error:
+	dev_err(priv->dev, "%s: error: %i\n", __func__, ret);
+
+	return ret;
+}
+
 static int ar9331_sw_setup(struct dsa_switch *ds)
 {
 	struct ar9331_sw_priv *priv = (struct ar9331_sw_priv *)ds->priv;
 	struct regmap *regmap = priv->regmap;
-	int ret;
+	int ret, i;
 
 	ret = ar9331_sw_reset(priv);
 	if (ret)
@@ -402,6 +467,12 @@ static int ar9331_sw_setup(struct dsa_switch *ds)
 	if (ret)
 		goto error;
 
+	for (i = 0; i < ds->num_ports; i++) {
+		ret = ar9331_sw_setup_port(ds, i);
+		if (ret)
+			goto error;
+	}
+
 	ds->configure_vlan_while_not_filtering = false;
 
 	return 0;