net: dsa: qca8k: move read_switch_id function to common code

The same function to read the switch id is used by drivers based on
qca8k family switch. Move them to common code to make them accessible
also by other drivers.
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/qca/qca8k-8xxx.c

@@ -1876,35 +1876,6 @@ static const struct dsa_switch_ops qca8k_switch_ops = {
 	.connect_tag_protocol	= qca8k_connect_tag_protocol,
 };
 
-static int qca8k_read_switch_id(struct qca8k_priv *priv)
-{
-	u32 val;
-	u8 id;
-	int ret;
-
-	if (!priv->info)
-		return -ENODEV;
-
-	ret = qca8k_read(priv, QCA8K_REG_MASK_CTRL, &val);
-	if (ret < 0)
-		return -ENODEV;
-
-	id = QCA8K_MASK_CTRL_DEVICE_ID(val);
-	if (id != priv->info->id) {
-		dev_err(priv->dev,
-			"Switch id detected %x but expected %x",
-			id, priv->info->id);
-		return -ENODEV;
-	}
-
-	priv->switch_id = id;
-
-	/* Save revision to communicate to the internal PHY driver */
-	priv->switch_revision = QCA8K_MASK_CTRL_REV_ID(val);
-
-	return 0;
-}
-
 static int
 qca8k_sw_probe(struct mdio_device *mdiodev)
 {

drivers/net/dsa/qca/qca8k-common.c

@@ -1179,3 +1179,32 @@ int qca8k_port_lag_leave(struct dsa_switch *ds, int port,
 {
 	return qca8k_lag_refresh_portmap(ds, port, lag, true);
 }
+
+int qca8k_read_switch_id(struct qca8k_priv *priv)
+{
+	u32 val;
+	u8 id;
+	int ret;
+
+	if (!priv->info)
+		return -ENODEV;
+
+	ret = qca8k_read(priv, QCA8K_REG_MASK_CTRL, &val);
+	if (ret < 0)
+		return -ENODEV;
+
+	id = QCA8K_MASK_CTRL_DEVICE_ID(val);
+	if (id != priv->info->id) {
+		dev_err(priv->dev,
+			"Switch id detected %x but expected %x",
+			id, priv->info->id);
+		return -ENODEV;
+	}
+
+	priv->switch_id = id;
+
+	/* Save revision to communicate to the internal PHY driver */
+	priv->switch_revision = QCA8K_MASK_CTRL_REV_ID(val);
+
+	return 0;
+}

drivers/net/dsa/qca/qca8k.h

@@ -432,6 +432,7 @@ extern const struct qca8k_mib_desc ar8327_mib[];
 extern const struct regmap_access_table qca8k_readable_table;
 int qca8k_mib_init(struct qca8k_priv *priv);
 void qca8k_port_set_status(struct qca8k_priv *priv, int port, int enable);
+int qca8k_read_switch_id(struct qca8k_priv *priv);
 
 /* Common read/write/rmw function */
 int qca8k_read(struct qca8k_priv *priv, u32 reg, u32 *val);