net: dsa: qca8k: drop port_sts from qca8k_priv

Port_sts is a thing of the past for this driver. It was something
present on the initial implementation of this driver and parts of the
original struct were dropped over time. Using an array of int to store if
a port is enabled or not to handle PM operation seems overkill. Switch
and use a simple u8 to store the port status where each bit correspond
to a port. (bit is set port is enabled, bit is not set, port is disabled)
Also add some comments to better describe why we need to track port
status.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/qca8k.c

@@ -2346,7 +2346,7 @@ qca8k_port_enable(struct dsa_switch *ds, int port,
 	struct qca8k_priv *priv = (struct qca8k_priv *)ds->priv;
 
 	qca8k_port_set_status(priv, port, 1);
-	priv->port_sts[port].enabled = 1;
+	priv->port_enabled_map |= BIT(port);
 
 	if (dsa_is_user_port(ds, port))
 		phy_support_asym_pause(phy);
@@ -2360,7 +2360,7 @@ qca8k_port_disable(struct dsa_switch *ds, int port)
 	struct qca8k_priv *priv = (struct qca8k_priv *)ds->priv;
 
 	qca8k_port_set_status(priv, port, 0);
-	priv->port_sts[port].enabled = 0;
+	priv->port_enabled_map &= ~BIT(port);
 }
 
 static int
@@ -3235,13 +3235,16 @@ static void qca8k_sw_shutdown(struct mdio_device *mdiodev)
 static void
 qca8k_set_pm(struct qca8k_priv *priv, int enable)
 {
-	int i;
+	int port;
 
-	for (i = 0; i < QCA8K_NUM_PORTS; i++) {
-		if (!priv->port_sts[i].enabled)
+	for (port = 0; port < QCA8K_NUM_PORTS; port++) {
+		/* Do not enable on resume if the port was
+		 * disabled before.
+		 */
+		if (!(priv->port_enabled_map & BIT(port)))
 			continue;
 
-		qca8k_port_set_status(priv, i, enable);
+		qca8k_port_set_status(priv, port, enable);
 	}
 }
 

drivers/net/dsa/qca8k.h

@@ -324,10 +324,6 @@ enum qca8k_mid_cmd {
 	QCA8K_MIB_CAST = 3,
 };
 
-struct ar8xxx_port_status {
-	int enabled;
-};
-
 struct qca8k_match_data {
 	u8 id;
 	bool reduced_package;
@@ -388,11 +384,14 @@ struct qca8k_priv {
 	u8 mirror_rx;
 	u8 mirror_tx;
 	u8 lag_hash_mode;
+	/* Each bit correspond to a port. This switch can support a max of 7 port.
+	 * Bit 1: port enabled. Bit 0: port disabled.
+	 */
+	u8 port_enabled_map;
 	bool legacy_phy_port_mapping;
 	struct qca8k_ports_config ports_config;
 	struct regmap *regmap;
 	struct mii_bus *bus;
-	struct ar8xxx_port_status port_sts[QCA8K_NUM_PORTS];
 	struct dsa_switch *ds;
 	struct mutex reg_mutex;
 	struct device *dev;