[net-next PATCH v4 04/13] drivers: net: dsa: qca8k: add support for cpu port 6

[Ansuel Smith <ansuelsmth@gmail.com>]

Currently CPU port is always hardcoded to port 0. This switch have 2 CPU
port. The original intention of this driver seems to be use the
mac06_exchange bit to swap MAC0 with MAC6 in the strange configuration
where device have connected only the CPU port 6. To skip the
introduction of a new binding, rework the driver to address the
secondary CPU port as primary and drop any reference of hardcoded port.
With configuration of mac06 exchange, just skip the definition of port0
and define the CPU port as a secondary. The driver will autoconfigure
the switch to use that as the primary CPU port.

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
---
 drivers/net/dsa/qca8k.c | 50 +++++++++++++++++++++++++++++------------
 drivers/net/dsa/qca8k.h |  2 --
 2 files changed, 36 insertions(+), 16 deletions(-)

diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c
index 3e4a12d6d61c..df0a622acdd7 100644
--- a/drivers/net/dsa/qca8k.c
+++ b/drivers/net/dsa/qca8k.c
@@ -977,17 +977,34 @@ qca8k_setup_mac_pwr_sel(struct qca8k_priv *priv)
 	return ret;
 }
 
+static int qca8k_find_cpu_port(struct dsa_switch *ds)
+{
+	struct qca8k_priv *priv = (struct qca8k_priv *)ds->priv;
+
+	/* Find the connected cpu port. Valid port are 0 or 6 */
+	if (dsa_is_cpu_port(ds, 0))
+		return 0;
+
+	dev_dbg(priv->dev, "port 0 is not the CPU port. Checking port 6");
+
+	if (dsa_is_cpu_port(ds, 6))
+		return 6;
+
+	return -EINVAL;
+}
+
 static int
 qca8k_setup(struct dsa_switch *ds)
 {
 	struct qca8k_priv *priv = (struct qca8k_priv *)ds->priv;
+	u8 cpu_port;
 	int ret, i;
 	u32 mask;
 
-	/* Make sure that port 0 is the cpu port */
-	if (!dsa_is_cpu_port(ds, 0)) {
-		dev_err(priv->dev, "port 0 is not the CPU port");
-		return -EINVAL;
+	cpu_port = qca8k_find_cpu_port(ds);
+	if (cpu_port < 0) {
+		dev_err(priv->dev, "No cpu port configured in both cpu port0 and port6");
+		return cpu_port;
 	}
 
 	mutex_init(&priv->reg_mutex);
@@ -1024,7 +1041,7 @@ qca8k_setup(struct dsa_switch *ds)
 		dev_warn(priv->dev, "mib init failed");
 
 	/* Enable QCA header mode on the cpu port */
-	ret = qca8k_write(priv, QCA8K_REG_PORT_HDR_CTRL(QCA8K_CPU_PORT),
+	ret = qca8k_write(priv, QCA8K_REG_PORT_HDR_CTRL(cpu_port),
 			  QCA8K_PORT_HDR_CTRL_ALL << QCA8K_PORT_HDR_CTRL_TX_S |
 			  QCA8K_PORT_HDR_CTRL_ALL << QCA8K_PORT_HDR_CTRL_RX_S);
 	if (ret) {
@@ -1046,10 +1063,10 @@ qca8k_setup(struct dsa_switch *ds)
 
 	/* Forward all unknown frames to CPU port for Linux processing */
 	ret = qca8k_write(priv, QCA8K_REG_GLOBAL_FW_CTRL1,
-			  BIT(0) << QCA8K_GLOBAL_FW_CTRL1_IGMP_DP_S |
-			  BIT(0) << QCA8K_GLOBAL_FW_CTRL1_BC_DP_S |
-			  BIT(0) << QCA8K_GLOBAL_FW_CTRL1_MC_DP_S |
-			  BIT(0) << QCA8K_GLOBAL_FW_CTRL1_UC_DP_S);
+			  BIT(cpu_port) << QCA8K_GLOBAL_FW_CTRL1_IGMP_DP_S |
+			  BIT(cpu_port) << QCA8K_GLOBAL_FW_CTRL1_BC_DP_S |
+			  BIT(cpu_port) << QCA8K_GLOBAL_FW_CTRL1_MC_DP_S |
+			  BIT(cpu_port) << QCA8K_GLOBAL_FW_CTRL1_UC_DP_S);
 	if (ret)
 		return ret;
 
@@ -1057,7 +1074,7 @@ qca8k_setup(struct dsa_switch *ds)
 	for (i = 0; i < QCA8K_NUM_PORTS; i++) {
 		/* CPU port gets connected to all user ports of the switch */
 		if (dsa_is_cpu_port(ds, i)) {
-			ret = qca8k_rmw(priv, QCA8K_PORT_LOOKUP_CTRL(QCA8K_CPU_PORT),
+			ret = qca8k_rmw(priv, QCA8K_PORT_LOOKUP_CTRL(cpu_port),
 					QCA8K_PORT_LOOKUP_MEMBER, dsa_user_ports(ds));
 			if (ret)
 				return ret;
@@ -1069,7 +1086,7 @@ qca8k_setup(struct dsa_switch *ds)
 
 			ret = qca8k_rmw(priv, QCA8K_PORT_LOOKUP_CTRL(i),
 					QCA8K_PORT_LOOKUP_MEMBER,
-					BIT(QCA8K_CPU_PORT));
+					BIT(cpu_port));
 			if (ret)
 				return ret;
 
@@ -1578,9 +1595,12 @@ static int
 qca8k_port_bridge_join(struct dsa_switch *ds, int port, struct net_device *br)
 {
 	struct qca8k_priv *priv = (struct qca8k_priv *)ds->priv;
-	int port_mask = BIT(QCA8K_CPU_PORT);
+	int port_mask, cpu_port;
 	int i, ret;
 
+	cpu_port = dsa_to_port(ds, port)->cpu_dp->index;
+	port_mask = BIT(cpu_port);
+
 	for (i = 1; i < QCA8K_NUM_PORTS; i++) {
 		if (dsa_to_port(ds, i)->bridge_dev != br)
 			continue;
@@ -1607,7 +1627,9 @@ static void
 qca8k_port_bridge_leave(struct dsa_switch *ds, int port, struct net_device *br)
 {
 	struct qca8k_priv *priv = (struct qca8k_priv *)ds->priv;
-	int i;
+	int cpu_port, i;
+
+	cpu_port = dsa_to_port(ds, port)->cpu_dp->index;
 
 	for (i = 1; i < QCA8K_NUM_PORTS; i++) {
 		if (dsa_to_port(ds, i)->bridge_dev != br)
@@ -1624,7 +1646,7 @@ qca8k_port_bridge_leave(struct dsa_switch *ds, int port, struct net_device *br)
 	 * this port
 	 */
 	qca8k_rmw(priv, QCA8K_PORT_LOOKUP_CTRL(port),
-		  QCA8K_PORT_LOOKUP_MEMBER, BIT(QCA8K_CPU_PORT));
+		  QCA8K_PORT_LOOKUP_MEMBER, BIT(cpu_port));
 }
 
 static int
diff --git a/drivers/net/dsa/qca8k.h b/drivers/net/dsa/qca8k.h
index 3fded69a6839..5df0f0ef6526 100644
--- a/drivers/net/dsa/qca8k.h
+++ b/drivers/net/dsa/qca8k.h
@@ -24,8 +24,6 @@
 
 #define QCA8K_NUM_FDB_RECORDS				2048
 
-#define QCA8K_CPU_PORT					0
-
 #define QCA8K_PORT_VID_DEF				1
 
 /* Global control registers */
-- 
2.32.0