[PATCH net-next 9/9] net: dsa: microchip: split ksz_connect_tag_protocol()

[Bastien Curutchet (Schneider Electric)]

All the KSZ switches use the same ksz_connect_tag_protocol while they
don't support all the KSZ tag protocols. So if, for some reason, a given
switch tries to connect another KSZ tag protocol, it won't fail.

Split the common ksz_connect_tag_protocol() into switch-specific
operations. This way, each switch will only accept to connect the tag
protocol it supports.
Remove the no longer used common operation.

Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@xxxxxxxxxxx>
---
 drivers/net/dsa/microchip/ksz8.c         | 51 ++++++++++++++++++++++++++++++--
 drivers/net/dsa/microchip/ksz9477.c      | 17 ++++++++++-
 drivers/net/dsa/microchip/ksz_common.c   | 19 ------------
 drivers/net/dsa/microchip/ksz_common.h   |  2 --
 drivers/net/dsa/microchip/lan937x_main.c | 17 ++++++++++-
 5 files changed, 80 insertions(+), 26 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz8.c b/drivers/net/dsa/microchip/ksz8.c
index fa2e1256323c2..abee0dc5ec04b 100644
--- a/drivers/net/dsa/microchip/ksz8.c
+++ b/drivers/net/dsa/microchip/ksz8.c
@@ -16,6 +16,7 @@
 
 #include <linux/bitfield.h>
 #include <linux/delay.h>
+#include <linux/dsa/ksz_common.h>
 #include <linux/export.h>
 #include <linux/gpio.h>
 #include <linux/if_vlan.h>
@@ -2107,6 +2108,20 @@ static enum dsa_tag_protocol ksz8463_get_tag_protocol(struct dsa_switch *ds,
 	return DSA_TAG_PROTO_KSZ9893;
 }
 
+static int ksz8463_connect_tag_protocol(struct dsa_switch *ds,
+					enum dsa_tag_protocol proto)
+{
+	struct ksz_tagger_data *tagger_data;
+
+	if (proto != DSA_TAG_PROTO_KSZ9893)
+		return -EPROTONOSUPPORT;
+
+	tagger_data = ksz_tagger_data(ds);
+	tagger_data->xmit_work_fn = ksz_port_deferred_xmit;
+
+	return 0;
+}
+
 static enum dsa_tag_protocol ksz87xx_get_tag_protocol(struct dsa_switch *ds,
 						      int port,
 						      enum dsa_tag_protocol mp)
@@ -2114,6 +2129,15 @@ static enum dsa_tag_protocol ksz87xx_get_tag_protocol(struct dsa_switch *ds,
 	return DSA_TAG_PROTO_KSZ8795;
 }
 
+static int ksz87xx_connect_tag_protocol(struct dsa_switch *ds,
+					enum dsa_tag_protocol proto)
+{
+	if (proto != DSA_TAG_PROTO_KSZ8795)
+		return -EPROTONOSUPPORT;
+
+	return 0;
+}
+
 static enum dsa_tag_protocol ksz88xx_get_tag_protocol(struct dsa_switch *ds,
 						      int port,
 						      enum dsa_tag_protocol mp)
@@ -2126,6 +2150,27 @@ static enum dsa_tag_protocol ksz88xx_get_tag_protocol(struct dsa_switch *ds,
 	return DSA_TAG_PROTO_KSZ9893;
 }
 
+static int ksz88xx_connect_tag_protocol(struct dsa_switch *ds,
+					enum dsa_tag_protocol proto)
+{
+	struct ksz_tagger_data *tagger_data;
+
+	if (ksz_is_8895_family(ds->priv)) { /* KSZ8864, KSZ8895 */
+		if (proto != DSA_TAG_PROTO_KSZ8795)
+			return -EPROTONOSUPPORT;
+
+		return 0;
+	}
+
+	if (proto != DSA_TAG_PROTO_KSZ9893)
+		return -EPROTONOSUPPORT;
+
+	tagger_data = ksz_tagger_data(ds);
+	tagger_data->xmit_work_fn = ksz_port_deferred_xmit;
+
+	return 0;
+}
+
 static void ksz88x3_phylink_mac_config(struct phylink_config *config,
 				       unsigned int mode,
 				       const struct phylink_link_state *state)
@@ -2256,7 +2301,7 @@ const struct ksz_dev_ops ksz88xx_dev_ops = {
 
 const struct dsa_switch_ops ksz8463_switch_ops = {
 	.get_tag_protocol	= ksz8463_get_tag_protocol,
-	.connect_tag_protocol   = ksz_connect_tag_protocol,
+	.connect_tag_protocol   = ksz8463_connect_tag_protocol,
 	.get_phy_flags		= ksz_get_phy_flags,
 	.setup			= ksz_setup,
 	.teardown		= ksz_teardown,
@@ -2317,7 +2362,7 @@ const struct dsa_switch_ops ksz8463_switch_ops = {
 
 const struct dsa_switch_ops ksz87xx_switch_ops = {
 	.get_tag_protocol	= ksz87xx_get_tag_protocol,
-	.connect_tag_protocol   = ksz_connect_tag_protocol,
+	.connect_tag_protocol   = ksz87xx_connect_tag_protocol,
 	.get_phy_flags		= ksz_get_phy_flags,
 	.setup			= ksz_setup,
 	.teardown		= ksz_teardown,
@@ -2378,7 +2423,7 @@ const struct dsa_switch_ops ksz87xx_switch_ops = {
 
 const struct dsa_switch_ops ksz88xx_switch_ops = {
 	.get_tag_protocol	= ksz88xx_get_tag_protocol,
-	.connect_tag_protocol   = ksz_connect_tag_protocol,
+	.connect_tag_protocol   = ksz88xx_connect_tag_protocol,
 	.get_phy_flags		= ksz_get_phy_flags,
 	.setup			= ksz_setup,
 	.teardown		= ksz_teardown,
diff --git a/drivers/net/dsa/microchip/ksz9477.c b/drivers/net/dsa/microchip/ksz9477.c
index 9bac95bb079ff..ac2c63fe0588c 100644
--- a/drivers/net/dsa/microchip/ksz9477.c
+++ b/drivers/net/dsa/microchip/ksz9477.c
@@ -5,6 +5,7 @@
  * Copyright (C) 2017-2025 Microchip Technology Inc.
  */
 
+#include <linux/dsa/ksz_common.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/iopoll.h>
@@ -1624,6 +1625,20 @@ static enum dsa_tag_protocol ksz9477_get_tag_protocol(struct dsa_switch *ds,
 	return DSA_TAG_PROTO_KSZ9477;
 }
 
+static int ksz9477_connect_tag_protocol(struct dsa_switch *ds,
+					enum dsa_tag_protocol proto)
+{
+	struct ksz_tagger_data *tagger_data;
+
+	if (proto != DSA_TAG_PROTO_KSZ9893 && proto != DSA_TAG_PROTO_KSZ9477)
+		return -EPROTONOSUPPORT;
+
+	tagger_data = ksz_tagger_data(ds);
+	tagger_data->xmit_work_fn = ksz_port_deferred_xmit;
+
+	return 0;
+}
+
 static void ksz9477_set_gbit(struct ksz_device *dev, int port, bool gbit)
 {
 	const u8 *bitval = dev->info->xmii_ctrl1;
@@ -1790,7 +1805,7 @@ const struct ksz_dev_ops ksz9477_dev_ops = {
 
 const struct dsa_switch_ops ksz9477_switch_ops = {
 	.get_tag_protocol	= ksz9477_get_tag_protocol,
-	.connect_tag_protocol   = ksz_connect_tag_protocol,
+	.connect_tag_protocol   = ksz9477_connect_tag_protocol,
 	.get_phy_flags		= ksz_get_phy_flags,
 	.setup			= ksz_setup,
 	.teardown		= ksz_teardown,
diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index 1be055d3f1994..426414a218455 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -3304,25 +3304,6 @@ int ksz_port_bridge_flags(struct dsa_switch *ds, int port,
 	return 0;
 }
 
-int ksz_connect_tag_protocol(struct dsa_switch *ds,
-			     enum dsa_tag_protocol proto)
-{
-	struct ksz_tagger_data *tagger_data;
-
-	switch (proto) {
-	case DSA_TAG_PROTO_KSZ8795:
-		return 0;
-	case DSA_TAG_PROTO_KSZ9893:
-	case DSA_TAG_PROTO_KSZ9477:
-	case DSA_TAG_PROTO_LAN937X:
-		tagger_data = ksz_tagger_data(ds);
-		tagger_data->xmit_work_fn = ksz_port_deferred_xmit;
-		return 0;
-	default:
-		return -EPROTONOSUPPORT;
-	}
-}
-
 int ksz_port_vlan_filtering(struct dsa_switch *ds, int port,
 			    bool flag, struct netlink_ext_ack *extack)
 {
diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index 39486b5571bd6..3dde7e7717272 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -473,8 +473,6 @@ void ksz_teardown(struct dsa_switch *ds);
 int ksz_port_setup(struct dsa_switch *ds, int port);
 void ksz_port_teardown(struct dsa_switch *ds, int port);
 
-int ksz_connect_tag_protocol(struct dsa_switch *ds,
-			     enum dsa_tag_protocol proto);
 void ksz_init_mib_timer(struct ksz_device *dev);
 bool ksz_is_port_mac_global_usable(struct dsa_switch *ds, int port);
 void ksz_r_mib_stats64(struct ksz_device *dev, int port);
diff --git a/drivers/net/dsa/microchip/lan937x_main.c b/drivers/net/dsa/microchip/lan937x_main.c
index c39be6eb50121..e522990cce22e 100644
--- a/drivers/net/dsa/microchip/lan937x_main.c
+++ b/drivers/net/dsa/microchip/lan937x_main.c
@@ -2,6 +2,7 @@
 /* Microchip LAN937X switch driver main logic
  * Copyright (C) 2019-2024 Microchip Technology Inc.
  */
+#include <linux/dsa/ksz_common.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/iopoll.h>
@@ -674,6 +675,20 @@ static enum dsa_tag_protocol lan937x_get_tag_protocol(struct dsa_switch *ds,
 	return DSA_TAG_PROTO_LAN937X;
 }
 
+static int lan937x_connect_tag_protocol(struct dsa_switch *ds,
+					enum dsa_tag_protocol proto)
+{
+	struct ksz_tagger_data *tagger_data;
+
+	if (proto != DSA_TAG_PROTO_LAN937X)
+		return -EPROTONOSUPPORT;
+
+	tagger_data = ksz_tagger_data(ds);
+	tagger_data->xmit_work_fn = ksz_port_deferred_xmit;
+
+	return 0;
+}
+
 const struct phylink_mac_ops lan937x_phylink_mac_ops = {
 	.mac_config	= ksz_phylink_mac_config,
 	.mac_link_down	= ksz_phylink_mac_link_down,
@@ -722,7 +737,7 @@ const struct ksz_dev_ops lan937x_dev_ops = {
 
 const struct dsa_switch_ops lan937x_switch_ops = {
 	.get_tag_protocol	= lan937x_get_tag_protocol,
-	.connect_tag_protocol   = ksz_connect_tag_protocol,
+	.connect_tag_protocol   = lan937x_connect_tag_protocol,
 	.get_phy_flags		= ksz_get_phy_flags,
 	.setup			= ksz_setup,
 	.teardown		= ksz_teardown,

-- 
2.53.0