net: dsa: Add DSA driver for Hirschmann Hellcreek switches

Add a basic DSA driver for Hirschmann Hellcreek switches. Those switches are
implementing features needed for Time Sensitive Networking (TSN) such as support
for the Time Precision Protocol and various shapers like the Time Aware Shaper.

This driver includes basic support for networking:

 * VLAN handling
 * FDB handling
 * Port statistics
 * STP
 * Phylink

Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/Kconfig

@@ -24,6 +24,8 @@ config NET_DSA_LOOP
 	  This enables support for a fake mock-up switch chip which
 	  exercises the DSA APIs.
 
+source "drivers/net/dsa/hirschmann/Kconfig"
+
 config NET_DSA_LANTIQ_GSWIP
 	tristate "Lantiq / Intel GSWIP"
 	depends on HAS_IOMEM && NET_DSA

drivers/net/dsa/Makefile

@@ -18,6 +18,7 @@ obj-$(CONFIG_NET_DSA_VITESSE_VSC73XX) += vitesse-vsc73xx-core.o
 obj-$(CONFIG_NET_DSA_VITESSE_VSC73XX_PLATFORM) += vitesse-vsc73xx-platform.o
 obj-$(CONFIG_NET_DSA_VITESSE_VSC73XX_SPI) += vitesse-vsc73xx-spi.o
 obj-y				+= b53/
+obj-y				+= hirschmann/
 obj-y				+= microchip/
 obj-y				+= mv88e6xxx/
 obj-y				+= ocelot/

drivers/net/dsa/hirschmann/Kconfig

@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0
+config NET_DSA_HIRSCHMANN_HELLCREEK
+	tristate "Hirschmann Hellcreek TSN Switch support"
+	depends on HAS_IOMEM
+	depends on NET_DSA
+	select NET_DSA_TAG_HELLCREEK
+	help
+	  This driver adds support for Hirschmann Hellcreek TSN switches.

drivers/net/dsa/hirschmann/Makefile

@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_NET_DSA_HIRSCHMANN_HELLCREEK)	+= hellcreek.o