net: dsa: microchip: add support for different DCB app configurations

Add DCB support to configure app trust sources and default port priority.

Following commands can be used for testing:
dcb apptrust set dev lan1 order pcp dscp
dcb app replace dev lan1 default-prio 3

Since it is not possible to configure DSCP-Prio mapping per port, this
patch provide only ability to read switch global dscp-prio mapping and
way to enable/disable app trust for DSCP.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/microchip/Kconfig

@@ -4,6 +4,8 @@ menuconfig NET_DSA_MICROCHIP_KSZ_COMMON
 	depends on NET_DSA
 	select NET_DSA_TAG_KSZ
 	select NET_DSA_TAG_NONE
+	select NET_IEEE8021Q_HELPERS
+	select DCB
 	help
 	  This driver adds support for Microchip KSZ9477 series switch and
 	  KSZ8795/KSZ88x3 switch chips.

drivers/net/dsa/microchip/Makefile

 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_NET_DSA_MICROCHIP_KSZ_COMMON)	+= ksz_switch.o
-ksz_switch-objs := ksz_common.o
+ksz_switch-objs := ksz_common.o ksz_dcb.o
 ksz_switch-objs += ksz9477.o ksz9477_acl.o ksz9477_tc_flower.o
 ksz_switch-objs += ksz8795.o
 ksz_switch-objs += lan937x_main.o

drivers/net/dsa/microchip/ksz_common.c

@@ -28,6 +28,7 @@
 #include <net/switchdev.h>
 
 #include "ksz_common.h"
+#include "ksz_dcb.h"
 #include "ksz_ptp.h"
 #include "ksz8.h"
 #include "ksz9477.h"
@@ -2411,6 +2412,10 @@ static int ksz_setup(struct dsa_switch *ds)
 		goto out_ptp_clock_unregister;
 	}
 
+	ret = ksz_dcb_init(dev);
+	if (ret)
+		goto out_ptp_clock_unregister;
+
 	/* start switch */
 	regmap_update_bits(ksz_regmap_8(dev), regs[S_START_CTRL],
 			   SW_START, SW_START);
@@ -2739,7 +2744,7 @@ static int ksz_port_setup(struct dsa_switch *ds, int port)
 	 * there is no need to do anything.
 	 */
 
-	return 0;
+	return ksz_dcb_init_port(dev, port);
 }
 
 void ksz_port_stp_state_set(struct dsa_switch *ds, int port, u8 state)
@@ -3982,6 +3987,11 @@ static const struct dsa_switch_ops ksz_switch_ops = {
 	.port_setup_tc		= ksz_setup_tc,
 	.get_mac_eee		= ksz_get_mac_eee,
 	.set_mac_eee		= ksz_set_mac_eee,
+	.port_get_default_prio	= ksz_port_get_default_prio,
+	.port_set_default_prio	= ksz_port_set_default_prio,
+	.port_get_dscp_prio	= ksz_port_get_dscp_prio,
+	.port_get_apptrust	= ksz_port_get_apptrust,
+	.port_set_apptrust	= ksz_port_set_apptrust,
 };
 
 struct ksz_device *ksz_switch_alloc(struct device *base, void *priv)

drivers/net/dsa/microchip/ksz_common.h

@@ -620,6 +620,11 @@ static inline bool ksz_is_ksz88x3(struct ksz_device *dev)
 	return dev->chip_id == KSZ8830_CHIP_ID;
 }
 
+static inline bool is_ksz8(struct ksz_device *dev)
+{
+	return ksz_is_ksz87xx(dev) || ksz_is_ksz88x3(dev);
+}
+
 static inline int is_lan937x(struct ksz_device *dev)
 {
 	return dev->chip_id == LAN9370_CHIP_ID ||

drivers/net/dsa/microchip/ksz_dcb.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2024 Pengutronix, Oleksij Rempel <kernel@pengutronix.de> */
+
+#ifndef __KSZ_DCB_H
+#define __KSZ_DCB_H
+
+#include <net/dsa.h>
+
+#include "ksz_common.h"
+
+int ksz_port_get_default_prio(struct dsa_switch *ds, int port);
+int ksz_port_set_default_prio(struct dsa_switch *ds, int port, u8 prio);
+int ksz_port_get_dscp_prio(struct dsa_switch *ds, int port, u8 dscp);
+int ksz_port_set_apptrust(struct dsa_switch *ds, int port,
+			  const unsigned char *sel,
+			  int nsel);
+int ksz_port_get_apptrust(struct dsa_switch *ds, int port, u8 *sel, int *nsel);
+int ksz_dcb_init_port(struct ksz_device *dev, int port);
+int ksz_dcb_init(struct ksz_device *dev);
+
+#endif /* __KSZ_DCB_H */