Merge branch 'arrow-speedchips-xrs700x-dsa-driver'

George McCollister says:

====================
Arrow SpeedChips XRS700x DSA Driver

This series adds a DSA driver for the Arrow SpeedChips XRS 7000 series
of HSR/PRP gigabit switch chips.

The chips use Flexibilis IP.
More information can be found here:
 https://www.flexibilis.com/products/speedchips-xrs7000/

The switches have up to three RGMII ports and one MII port and are
managed via mdio or i2c. They use a one byte trailing tag to identify
the switch port when in managed mode so I've added a tag driver which
implements this.

This series contains minimal DSA functionality which may be built upon
in future patches. The ultimate goal is to add HSR and PRP
(IEC 62439-3 Clause 5 & 4) offloading with integration into net/hsr.
====================

Link: https://lore.kernel.org/r/20210114195734.55313-1-george.mccollister@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

14 files changed, 1356 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/net/dsa/arrow,xrs700x.yaml b/Documentation/devicetree/bindings/net/dsa/arrow,xrs700x.yaml
new file mode 100644
index 000000000000..3f01b65f3b22
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/dsa/arrow,xrs700x.yaml
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/dsa/arrow,xrs700x.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Arrow SpeedChips XRS7000 Series Switch Device Tree Bindings
+
+allOf:
+  - $ref: dsa.yaml#
+
+maintainers:
+  - George McCollister <george.mccollister@gmail.com>
+
+description:
+  The Arrow SpeedChips XRS7000 Series of single chip gigabit Ethernet switches
+  are designed for critical networking applications. They have up to three
+  RGMII ports and one RMII port and are managed via i2c or mdio.
+
+properties:
+  compatible:
+    oneOf:
+      - enum:
+          - arrow,xrs7003e
+          - arrow,xrs7003f
+          - arrow,xrs7004e
+          - arrow,xrs7004f
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        switch@8 {
+            compatible = "arrow,xrs7004e";
+            reg = <0x8>;
+
+            ethernet-ports {
+                #address-cells = <1>;
+                #size-cells = <0>;
+                ethernet-port@1 {
+                    reg = <1>;
+                    label = "lan0";
+                    phy-handle = <&swphy0>;
+                    phy-mode = "rgmii-id";
+                };
+                ethernet-port@2 {
+                    reg = <2>;
+                    label = "lan1";
+                    phy-handle = <&swphy1>;
+                    phy-mode = "rgmii-id";
+                };
+                ethernet-port@3 {
+                    reg = <3>;
+                    label = "cpu";
+                    ethernet = <&fec1>;
+                    fixed-link {
+                        speed = <1000>;
+                        full-duplex;
+                    };
+                };
+            };
+        };
+    };
diff --git a/drivers/net/dsa/Kconfig b/drivers/net/dsa/Kconfig
index f6a0488589fc..3af373e90806 100644
--- a/drivers/net/dsa/Kconfig
+++ b/drivers/net/dsa/Kconfig
@@ -60,6 +60,8 @@ source "drivers/net/dsa/qca/Kconfig"
 
 source "drivers/net/dsa/sja1105/Kconfig"
 
+source "drivers/net/dsa/xrs700x/Kconfig"
+
 config NET_DSA_QCA8K
 	tristate "Qualcomm Atheros QCA8K Ethernet switch family support"
 	depends on NET_DSA
diff --git a/drivers/net/dsa/Makefile b/drivers/net/dsa/Makefile
index a84adb140a04..f3598c040994 100644
--- a/drivers/net/dsa/Makefile
+++ b/drivers/net/dsa/Makefile
@@ -24,3 +24,4 @@ obj-y				+= mv88e6xxx/
 obj-y				+= ocelot/
 obj-y				+= qca/
 obj-y				+= sja1105/
+obj-y				+= xrs700x/
diff --git a/drivers/net/dsa/xrs700x/Kconfig b/drivers/net/dsa/xrs700x/Kconfig
new file mode 100644
index 000000000000..d10a4dce1676
--- /dev/null
+++ b/drivers/net/dsa/xrs700x/Kconfig
@@ -0,0 +1,26 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config NET_DSA_XRS700X
+	tristate
+	depends on NET_DSA
+	select NET_DSA_TAG_XRS700X
+	select REGMAP
+	help
+	  This enables support for Arrow SpeedChips XRS7003/7004 gigabit
+	  Ethernet switches.
+
+config NET_DSA_XRS700X_I2C
+	tristate "Arrow XRS7000X series switch in I2C mode"
+	depends on NET_DSA && I2C
+	select NET_DSA_XRS700X
+	select REGMAP_I2C
+	help
+	  Enable I2C support for Arrow SpeedChips XRS7003/7004 gigabit Ethernet
+	  switches.
+
+config NET_DSA_XRS700X_MDIO
+	tristate "Arrow XRS7000X series switch in MDIO mode"
+	depends on NET_DSA
+	select NET_DSA_XRS700X
+	help
+	  Enable MDIO support for Arrow SpeedChips XRS7003/7004 gigabit Ethernet
+	  switches.
diff --git a/drivers/net/dsa/xrs700x/Makefile b/drivers/net/dsa/xrs700x/Makefile
new file mode 100644
index 000000000000..51a3a7d9296a
--- /dev/null
+++ b/drivers/net/dsa/xrs700x/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_NET_DSA_XRS700X) += xrs700x.o
+obj-$(CONFIG_NET_DSA_XRS700X_I2C) += xrs700x_i2c.o
+obj-$(CONFIG_NET_DSA_XRS700X_MDIO) += xrs700x_mdio.o
diff --git a/drivers/net/dsa/xrs700x/xrs700x.c b/drivers/net/dsa/xrs700x/xrs700x.c
new file mode 100644
index 000000000000..259f5e657c46
--- /dev/null
+++ b/drivers/net/dsa/xrs700x/xrs700x.c
@@ -0,0 +1,622 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 NovaTech LLC
+ * George McCollister <george.mccollister@gmail.com>
+ */
+
+#include <net/dsa.h>
+#include <linux/if_bridge.h>
+#include <linux/of_device.h>
+#include "xrs700x.h"
+#include "xrs700x_reg.h"
+
+#define XRS700X_MIB_INTERVAL msecs_to_jiffies(3000)
+
+#define XRS7003E_ID	0x100
+#define XRS7003F_ID	0x101
+#define XRS7004E_ID	0x200
+#define XRS7004F_ID	0x201
+
+const struct xrs700x_info xrs7003e_info = {XRS7003E_ID, "XRS7003E", 3};
+EXPORT_SYMBOL(xrs7003e_info);
+
+const struct xrs700x_info xrs7003f_info = {XRS7003F_ID, "XRS7003F", 3};
+EXPORT_SYMBOL(xrs7003f_info);
+
+const struct xrs700x_info xrs7004e_info = {XRS7004E_ID, "XRS7004E", 4};
+EXPORT_SYMBOL(xrs7004e_info);
+
+const struct xrs700x_info xrs7004f_info = {XRS7004F_ID, "XRS7004F", 4};
+EXPORT_SYMBOL(xrs7004f_info);
+
+struct xrs700x_regfield {
+	struct reg_field rf;
+	struct regmap_field **rmf;
+};
+
+struct xrs700x_mib {
+	unsigned int offset;
+	const char *name;
+	int stats64_offset;
+};
+
+#define XRS700X_MIB_ETHTOOL_ONLY(o, n) {o, n, -1}
+#define XRS700X_MIB(o, n, m) {o, n, offsetof(struct rtnl_link_stats64, m)}
+
+static const struct xrs700x_mib xrs700x_mibs[] = {
+	XRS700X_MIB(XRS_RX_GOOD_OCTETS_L, "rx_good_octets", rx_bytes),
+	XRS700X_MIB_ETHTOOL_ONLY(XRS_RX_BAD_OCTETS_L, "rx_bad_octets"),
+	XRS700X_MIB(XRS_RX_UNICAST_L, "rx_unicast", rx_packets),
+	XRS700X_MIB(XRS_RX_BROADCAST_L, "rx_broadcast", rx_packets),
+	XRS700X_MIB(XRS_RX_MULTICAST_L, "rx_multicast", multicast),
+	XRS700X_MIB(XRS_RX_UNDERSIZE_L, "rx_undersize", rx_length_errors),
+	XRS700X_MIB(XRS_RX_FRAGMENTS_L, "rx_fragments", rx_length_errors),
+	XRS700X_MIB(XRS_RX_OVERSIZE_L, "rx_oversize", rx_length_errors),
+	XRS700X_MIB(XRS_RX_JABBER_L, "rx_jabber", rx_length_errors),
+	XRS700X_MIB(XRS_RX_ERR_L, "rx_err", rx_errors),
+	XRS700X_MIB(XRS_RX_CRC_L, "rx_crc", rx_crc_errors),
+	XRS700X_MIB_ETHTOOL_ONLY(XRS_RX_64_L, "rx_64"),
+	XRS700X_MIB_ETHTOOL_ONLY(XRS_RX_65_127_L, "rx_65_127"),
+	XRS700X_MIB_ETHTOOL_ONLY(XRS_RX_128_255_L, "rx_128_255"),
+	XRS700X_MIB_ETHTOOL_ONLY(XRS_RX_256_511_L, "rx_256_511"),
+	XRS700X_MIB_ETHTOOL_ONLY(XRS_RX_512_1023_L, "rx_512_1023"),
+	XRS700X_MIB_ETHTOOL_ONLY(XRS_RX_1024_1536_L, "rx_1024_1536"),
+	XRS700X_MIB_ETHTOOL_ONLY(XRS_RX_HSR_PRP_L, "rx_hsr_prp"),
+	XRS700X_MIB_ETHTOOL_ONLY(XRS_RX_WRONGLAN_L, "rx_wronglan"),
+	XRS700X_MIB_ETHTOOL_ONLY(XRS_RX_DUPLICATE_L, "rx_duplicate"),
+	XRS700X_MIB(XRS_TX_OCTETS_L, "tx_octets", tx_bytes),
+	XRS700X_MIB(XRS_TX_UNICAST_L, "tx_unicast", tx_packets),
+	XRS700X_MIB(XRS_TX_BROADCAST_L, "tx_broadcast", tx_packets),
+	XRS700X_MIB(XRS_TX_MULTICAST_L, "tx_multicast", tx_packets),
+	XRS700X_MIB_ETHTOOL_ONLY(XRS_TX_HSR_PRP_L, "tx_hsr_prp"),
+	XRS700X_MIB(XRS_PRIQ_DROP_L, "priq_drop", tx_dropped),
+	XRS700X_MIB(XRS_EARLY_DROP_L, "early_drop", tx_dropped),
+};
+
+static void xrs700x_get_strings(struct dsa_switch *ds, int port,
+				u32 stringset, u8 *data)
+{
+	int i;
+
+	if (stringset != ETH_SS_STATS)
+		return;
+
+	for (i = 0; i < ARRAY_SIZE(xrs700x_mibs); i++) {
+		strscpy(data, xrs700x_mibs[i].name, ETH_GSTRING_LEN);
+		data += ETH_GSTRING_LEN;
+	}
+}
+
+static int xrs700x_get_sset_count(struct dsa_switch *ds, int port, int sset)
+{
+	if (sset != ETH_SS_STATS)
+		return -EOPNOTSUPP;
+
+	return ARRAY_SIZE(xrs700x_mibs);
+}
+
+static void xrs700x_read_port_counters(struct xrs700x *priv, int port)
+{
+	struct xrs700x_port *p = &priv->ports[port];
+	struct rtnl_link_stats64 stats;
+	int i;
+
+	memset(&stats, 0, sizeof(stats));
+
+	mutex_lock(&p->mib_mutex);
+
+	/* Capture counter values */
+	regmap_write(priv->regmap, XRS_CNT_CTRL(port), 1);
+
+	for (i = 0; i < ARRAY_SIZE(xrs700x_mibs); i++) {
+		unsigned int high = 0, low = 0, reg;
+
+		reg = xrs700x_mibs[i].offset + XRS_PORT_OFFSET * port;
+		regmap_read(priv->regmap, reg, &low);
+		regmap_read(priv->regmap, reg + 2, &high);
+
+		p->mib_data[i] += (high << 16) | low;
+
+		if (xrs700x_mibs[i].stats64_offset >= 0) {
+			u8 *s = (u8 *)&stats + xrs700x_mibs[i].stats64_offset;
+			*(u64 *)s += p->mib_data[i];
+		}
+	}
+
+	/* multicast must be added to rx_packets (which already includes
+	 * unicast and broadcast)
+	 */
+	stats.rx_packets += stats.multicast;
+
+	u64_stats_update_begin(&p->syncp);
+	p->stats64 = stats;
+	u64_stats_update_end(&p->syncp);
+
+	mutex_unlock(&p->mib_mutex);
+}
+
+static void xrs700x_mib_work(struct work_struct *work)
+{
+	struct xrs700x *priv = container_of(work, struct xrs700x,
+					    mib_work.work);
+	int i;
+
+	for (i = 0; i < priv->ds->num_ports; i++)
+		xrs700x_read_port_counters(priv, i);
+
+	schedule_delayed_work(&priv->mib_work, XRS700X_MIB_INTERVAL);
+}
+
+static void xrs700x_get_ethtool_stats(struct dsa_switch *ds, int port,
+				      u64 *data)
+{
+	struct xrs700x *priv = ds->priv;
+	struct xrs700x_port *p = &priv->ports[port];
+
+	xrs700x_read_port_counters(priv, port);
+
+	mutex_lock(&p->mib_mutex);
+	memcpy(data, p->mib_data, sizeof(*data) * ARRAY_SIZE(xrs700x_mibs));
+	mutex_unlock(&p->mib_mutex);
+}
+
+static void xrs700x_get_stats64(struct dsa_switch *ds, int port,
+				struct rtnl_link_stats64 *s)
+{
+	struct xrs700x *priv = ds->priv;
+	struct xrs700x_port *p = &priv->ports[port];
+	unsigned int start;
+
+	do {
+		start = u64_stats_fetch_begin(&p->syncp);
+		*s = p->stats64;
+	} while (u64_stats_fetch_retry(&p->syncp, start));
+}
+
+static int xrs700x_setup_regmap_range(struct xrs700x *priv)
+{
+	struct xrs700x_regfield regfields[] = {
+		{
+			.rf = REG_FIELD_ID(XRS_PORT_STATE(0), 0, 1,
+					   priv->ds->num_ports,
+					   XRS_PORT_OFFSET),
+			.rmf = &priv->ps_forward
+		},
+		{
+			.rf = REG_FIELD_ID(XRS_PORT_STATE(0), 2, 3,
+					   priv->ds->num_ports,
+					   XRS_PORT_OFFSET),
+			.rmf = &priv->ps_management
+		},
+		{
+			.rf = REG_FIELD_ID(XRS_PORT_STATE(0), 4, 9,
+					   priv->ds->num_ports,
+					   XRS_PORT_OFFSET),
+			.rmf = &priv->ps_sel_speed
+		},
+		{
+			.rf = REG_FIELD_ID(XRS_PORT_STATE(0), 10, 11,
+					   priv->ds->num_ports,
+					   XRS_PORT_OFFSET),
+			.rmf = &priv->ps_cur_speed
+		}
+	};
+	int i = 0;
+
+	for (; i < ARRAY_SIZE(regfields); i++) {
+		*regfields[i].rmf = devm_regmap_field_alloc(priv->dev,
+							    priv->regmap,
+							    regfields[i].rf);
+		if (IS_ERR(*regfields[i].rmf))
+			return PTR_ERR(*regfields[i].rmf);
+	}
+
+	return 0;
+}
+
+static enum dsa_tag_protocol xrs700x_get_tag_protocol(struct dsa_switch *ds,
+						      int port,
+						      enum dsa_tag_protocol m)
+{
+	return DSA_TAG_PROTO_XRS700X;
+}
+
+static int xrs700x_reset(struct dsa_switch *ds)
+{
+	struct xrs700x *priv = ds->priv;
+	unsigned int val;
+	int ret;
+
+	ret = regmap_write(priv->regmap, XRS_GENERAL, XRS_GENERAL_RESET);
+	if (ret)
+		goto error;
+
+	ret = regmap_read_poll_timeout(priv->regmap, XRS_GENERAL,
+				       val, !(val & XRS_GENERAL_RESET),
+				       10, 1000);
+error:
+	if (ret) {
+		dev_err_ratelimited(priv->dev, "error resetting switch: %d\n",
+				    ret);
+	}
+
+	return ret;
+}
+
+static void xrs700x_port_stp_state_set(struct dsa_switch *ds, int port,
+				       u8 state)
+{
+	struct xrs700x *priv = ds->priv;
+	unsigned int bpdus = 1;
+	unsigned int val;
+
+	switch (state) {
+	case BR_STATE_DISABLED:
+		bpdus = 0;
+		fallthrough;
+	case BR_STATE_BLOCKING:
+	case BR_STATE_LISTENING:
+		val = XRS_PORT_DISABLED;
+		break;
+	case BR_STATE_LEARNING:
+		val = XRS_PORT_LEARNING;
+		break;
+	case BR_STATE_FORWARDING:
+		val = XRS_PORT_FORWARDING;
+		break;
+	default:
+		dev_err(ds->dev, "invalid STP state: %d\n", state);
+		return;
+	}
+
+	regmap_fields_write(priv->ps_forward, port, val);
+
+	/* Enable/disable inbound policy added by xrs700x_port_add_bpdu_ipf()
+	 * which allows BPDU forwarding to the CPU port when the front facing
+	 * port is in disabled/learning state.
+	 */
+	regmap_update_bits(priv->regmap, XRS_ETH_ADDR_CFG(port, 0), 1, bpdus);
+
+	dev_dbg_ratelimited(priv->dev, "%s - port: %d, state: %u, val: 0x%x\n",
+			    __func__, port, state, val);
+}
+
+/* Add an inbound policy filter which matches the BPDU destination MAC
+ * and forwards to the CPU port. Leave the policy disabled, it will be
+ * enabled as needed.
+ */
+static int xrs700x_port_add_bpdu_ipf(struct dsa_switch *ds, int port)
+{
+	struct xrs700x *priv = ds->priv;
+	unsigned int val = 0;
+	int i = 0;
+	int ret;
+
+	/* Compare all 48 bits of the destination MAC address. */
+	ret = regmap_write(priv->regmap, XRS_ETH_ADDR_CFG(port, 0), 48 << 2);
+	if (ret)
+		return ret;
+
+	/* match BPDU destination 01:80:c2:00:00:00 */
+	for (i = 0; i < sizeof(eth_stp_addr); i += 2) {
+		ret = regmap_write(priv->regmap, XRS_ETH_ADDR_0(port, 0) + i,
+				   eth_stp_addr[i] |
+				   (eth_stp_addr[i + 1] << 8));
+		if (ret)
+			return ret;
+	}
+
+	/* Mirror BPDU to CPU port */
+	for (i = 0; i < ds->num_ports; i++) {
+		if (dsa_is_cpu_port(ds, i))
+			val |= BIT(i);
+	}
+
+	ret = regmap_write(priv->regmap, XRS_ETH_ADDR_FWD_MIRROR(port, 0), val);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(priv->regmap, XRS_ETH_ADDR_FWD_ALLOW(port, 0), 0);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int xrs700x_port_setup(struct dsa_switch *ds, int port)
+{
+	bool cpu_port = dsa_is_cpu_port(ds, port);
+	struct xrs700x *priv = ds->priv;
+	unsigned int val = 0;
+	int ret, i;
+
+	xrs700x_port_stp_state_set(ds, port, BR_STATE_DISABLED);
+
+	/* Disable forwarding to non-CPU ports */
+	for (i = 0; i < ds->num_ports; i++) {
+		if (!dsa_is_cpu_port(ds, i))
+			val |= BIT(i);
+	}
+
+	/* 1 = Disable forwarding to the port */
+	ret = regmap_write(priv->regmap, XRS_PORT_FWD_MASK(port), val);
+	if (ret)
+		return ret;
+
+	val = cpu_port ? XRS_PORT_MODE_MANAGEMENT : XRS_PORT_MODE_NORMAL;
+	ret = regmap_fields_write(priv->ps_management, port, val);
+	if (ret)
+		return ret;
+
+	if (!cpu_port) {
+		ret = xrs700x_port_add_bpdu_ipf(ds, port);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int xrs700x_setup(struct dsa_switch *ds)
+{
+	struct xrs700x *priv = ds->priv;
+	int ret, i;
+
+	ret = xrs700x_reset(ds);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < ds->num_ports; i++) {
+		ret = xrs700x_port_setup(ds, i);
+		if (ret)
+			return ret;
+	}
+
+	schedule_delayed_work(&priv->mib_work, XRS700X_MIB_INTERVAL);
+
+	return 0;
+}
+
+static void xrs700x_teardown(struct dsa_switch *ds)
+{
+	struct xrs700x *priv = ds->priv;
+
+	cancel_delayed_work_sync(&priv->mib_work);
+}
+
+static void xrs700x_phylink_validate(struct dsa_switch *ds, int port,
+				     unsigned long *supported,
+				     struct phylink_link_state *state)
+{
+	__ETHTOOL_DECLARE_LINK_MODE_MASK(mask) = { 0, };
+
+	switch (port) {
+	case 0:
+		break;
+	case 1:
+	case 2:
+	case 3:
+		phylink_set(mask, 1000baseT_Full);
+		break;
+	default:
+		bitmap_zero(supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
+		dev_err(ds->dev, "Unsupported port: %i\n", port);
+		return;
+	}
+
+	phylink_set_port_modes(mask);
+
+	/* The switch only supports full duplex. */
+	phylink_set(mask, 10baseT_Full);
+	phylink_set(mask, 100baseT_Full);
+
+	bitmap_and(supported, supported, mask,
+		   __ETHTOOL_LINK_MODE_MASK_NBITS);
+	bitmap_and(state->advertising, state->advertising, mask,
+		   __ETHTOOL_LINK_MODE_MASK_NBITS);
+}
+
+static void xrs700x_mac_link_up(struct dsa_switch *ds, int port,
+				unsigned int mode, phy_interface_t interface,
+				struct phy_device *phydev,
+				int speed, int duplex,
+				bool tx_pause, bool rx_pause)
+{
+	struct xrs700x *priv = ds->priv;
+	unsigned int val;
+
+	switch (speed) {
+	case SPEED_1000:
+		val = XRS_PORT_SPEED_1000;
+		break;
+	case SPEED_100:
+		val = XRS_PORT_SPEED_100;
+		break;
+	case SPEED_10:
+		val = XRS_PORT_SPEED_10;
+		break;
+	default:
+		return;
+	}
+
+	regmap_fields_write(priv->ps_sel_speed, port, val);
+
+	dev_dbg_ratelimited(priv->dev, "%s: port: %d mode: %u speed: %u\n",
+			    __func__, port, mode, speed);
+}
+
+static int xrs700x_bridge_common(struct dsa_switch *ds, int port,
+				 struct net_device *bridge, bool join)
+{
+	unsigned int i, cpu_mask = 0, mask = 0;
+	struct xrs700x *priv = ds->priv;
+	int ret;
+
+	for (i = 0; i < ds->num_ports; i++) {
+		if (dsa_is_cpu_port(ds, i))
+			continue;
+
+		cpu_mask |= BIT(i);
+
+		if (dsa_to_port(ds, i)->bridge_dev == bridge)
+			continue;
+
+		mask |= BIT(i);
+	}
+
+	for (i = 0; i < ds->num_ports; i++) {
+		if (dsa_to_port(ds, i)->bridge_dev != bridge)
+			continue;
+
+		/* 1 = Disable forwarding to the port */
+		ret = regmap_write(priv->regmap, XRS_PORT_FWD_MASK(i), mask);
+		if (ret)
+			return ret;
+	}
+
+	if (!join) {
+		ret = regmap_write(priv->regmap, XRS_PORT_FWD_MASK(port),
+				   cpu_mask);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int xrs700x_bridge_join(struct dsa_switch *ds, int port,
+			       struct net_device *bridge)
+{
+	return xrs700x_bridge_common(ds, port, bridge, true);
+}
+
+static void xrs700x_bridge_leave(struct dsa_switch *ds, int port,
+				 struct net_device *bridge)
+{
+	xrs700x_bridge_common(ds, port, bridge, false);
+}
+
+static const struct dsa_switch_ops xrs700x_ops = {
+	.get_tag_protocol	= xrs700x_get_tag_protocol,
+	.setup			= xrs700x_setup,
+	.teardown		= xrs700x_teardown,
+	.port_stp_state_set	= xrs700x_port_stp_state_set,
+	.phylink_validate	= xrs700x_phylink_validate,
+	.phylink_mac_link_up	= xrs700x_mac_link_up,
+	.get_strings		= xrs700x_get_strings,
+	.get_sset_count		= xrs700x_get_sset_count,
+	.get_ethtool_stats	= xrs700x_get_ethtool_stats,
+	.get_stats64		= xrs700x_get_stats64,
+	.port_bridge_join	= xrs700x_bridge_join,
+	.port_bridge_leave	= xrs700x_bridge_leave,
+};
+
+static int xrs700x_detect(struct xrs700x *priv)
+{
+	const struct xrs700x_info *info;
+	unsigned int id;
+	int ret;
+
+	ret = regmap_read(priv->regmap, XRS_DEV_ID0, &id);
+	if (ret) {
+		dev_err(priv->dev, "error %d while reading switch id.\n",
+			ret);
+		return ret;
+	}
+
+	info = of_device_get_match_data(priv->dev);
+	if (!info)
+		return -EINVAL;
+
+	if (info->id == id) {
+		priv->ds->num_ports = info->num_ports;
+		dev_info(priv->dev, "%s detected.\n", info->name);
+		return 0;
+	}
+
+	dev_err(priv->dev, "expected switch id 0x%x but found 0x%x.\n",
+		info->id, id);
+
+	return -ENODEV;
+}
+
+struct xrs700x *xrs700x_switch_alloc(struct device *base, void *devpriv)
+{
+	struct dsa_switch *ds;
+	struct xrs700x *priv;
+
+	ds = devm_kzalloc(base, sizeof(*ds), GFP_KERNEL);
+	if (!ds)
+		return NULL;
+
+	ds->dev = base;
+
+	priv = devm_kzalloc(base, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return NULL;
+
+	INIT_DELAYED_WORK(&priv->mib_work, xrs700x_mib_work);
+
+	ds->ops = &xrs700x_ops;
+	ds->priv = priv;
+	priv->dev = base;
+
+	priv->ds = ds;
+	priv->priv = devpriv;
+
+	return priv;
+}
+EXPORT_SYMBOL(xrs700x_switch_alloc);
+
+static int xrs700x_alloc_port_mib(struct xrs700x *priv, int port)
+{
+	struct xrs700x_port *p = &priv->ports[port];
+
+	p->mib_data = devm_kcalloc(priv->dev, ARRAY_SIZE(xrs700x_mibs),
+				   sizeof(*p->mib_data), GFP_KERNEL);
+	if (!p->mib_data)
+		return -ENOMEM;
+
+	mutex_init(&p->mib_mutex);
+	u64_stats_init(&p->syncp);
+
+	return 0;
+}
+
+int xrs700x_switch_register(struct xrs700x *priv)
+{
+	int ret;
+	int i;
+
+	ret = xrs700x_detect(priv);
+	if (ret)
+		return ret;
+
+	ret = xrs700x_setup_regmap_range(priv);
+	if (ret)
+		return ret;
+
+	priv->ports = devm_kcalloc(priv->dev, priv->ds->num_ports,
+				   sizeof(*priv->ports), GFP_KERNEL);
+	if (!priv->ports)
+		return -ENOMEM;
+
+	for (i = 0; i < priv->ds->num_ports; i++) {
+		ret = xrs700x_alloc_port_mib(priv, i);
+		if (ret)
+			return ret;
+	}
+
+	return dsa_register_switch(priv->ds);
+}
+EXPORT_SYMBOL(xrs700x_switch_register);
+
+void xrs700x_switch_remove(struct xrs700x *priv)
+{
+	dsa_unregister_switch(priv->ds);
+}
+EXPORT_SYMBOL(xrs700x_switch_remove);
+
+MODULE_AUTHOR("George McCollister <george.mccollister@gmail.com>");
+MODULE_DESCRIPTION("Arrow SpeedChips XRS700x DSA driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/net/dsa/xrs700x/xrs700x.h b/drivers/net/dsa/xrs700x/xrs700x.h
new file mode 100644
index 000000000000..ff62cf61b091
--- /dev/null
+++ b/drivers/net/dsa/xrs700x/xrs700x.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/device.h>
+#include <linux/mutex.h>
+#include <linux/regmap.h>
+#include <linux/workqueue.h>
+#include <linux/u64_stats_sync.h>
+#include <uapi/linux/if_link.h>
+
+struct xrs700x_info {
+	unsigned int id;
+	const char *name;
+	size_t num_ports;
+};
+
+extern const struct xrs700x_info xrs7003e_info;
+extern const struct xrs700x_info xrs7003f_info;
+extern const struct xrs700x_info xrs7004e_info;
+extern const struct xrs700x_info xrs7004f_info;
+
+struct xrs700x_port {
+	struct mutex mib_mutex; /* protects mib_data */
+	u64 *mib_data;
+	struct rtnl_link_stats64 stats64;
+	struct u64_stats_sync syncp;
+};
+
+struct xrs700x {
+	struct dsa_switch *ds;
+	struct device *dev;
+	void *priv;
+	struct regmap *regmap;
+	struct regmap_field *ps_forward;
+	struct regmap_field *ps_management;
+	struct regmap_field *ps_sel_speed;
+	struct regmap_field *ps_cur_speed;
+	struct delayed_work mib_work;
+	struct xrs700x_port *ports;
+};
+
+struct xrs700x *xrs700x_switch_alloc(struct device *base, void *devpriv);
+int xrs700x_switch_register(struct xrs700x *priv);
+void xrs700x_switch_remove(struct xrs700x *priv);
diff --git a/drivers/net/dsa/xrs700x/xrs700x_i2c.c b/drivers/net/dsa/xrs700x/xrs700x_i2c.c
new file mode 100644
index 000000000000..a5f8883af829
--- /dev/null
+++ b/drivers/net/dsa/xrs700x/xrs700x_i2c.c
@@ -0,0 +1,150 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 NovaTech LLC
+ * George McCollister <george.mccollister@gmail.com>
+ */
+
+#include <linux/bits.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include "xrs700x.h"
+#include "xrs700x_reg.h"
+
+static int xrs700x_i2c_reg_read(void *context, unsigned int reg,
+				unsigned int *val)
+{
+	struct device *dev = context;
+	struct i2c_client *i2c = to_i2c_client(dev);
+	unsigned char buf[4];
+	int ret;
+
+	buf[0] = reg >> 23 & 0xff;
+	buf[1] = reg >> 15 & 0xff;
+	buf[2] = reg >> 7 & 0xff;
+	buf[3] = (reg & 0x7f) << 1;
+
+	ret = i2c_master_send(i2c, buf, sizeof(buf));
+	if (ret < 0) {
+		dev_err(dev, "xrs i2c_master_send returned %d\n", ret);
+		return ret;
+	}
+
+	ret = i2c_master_recv(i2c, buf, 2);
+	if (ret < 0) {
+		dev_err(dev, "xrs i2c_master_recv returned %d\n", ret);
+		return ret;
+	}
+
+	*val = buf[0] << 8 | buf[1];
+
+	return 0;
+}
+
+static int xrs700x_i2c_reg_write(void *context, unsigned int reg,
+				 unsigned int val)
+{
+	struct device *dev = context;
+	struct i2c_client *i2c = to_i2c_client(dev);
+	unsigned char buf[6];
+	int ret;
+
+	buf[0] = reg >> 23 & 0xff;
+	buf[1] = reg >> 15 & 0xff;
+	buf[2] = reg >> 7 & 0xff;
+	buf[3] = (reg & 0x7f) << 1 | 1;
+	buf[4] = val >> 8 & 0xff;
+	buf[5] = val & 0xff;
+
+	ret = i2c_master_send(i2c, buf, sizeof(buf));
+	if (ret < 0) {
+		dev_err(dev, "xrs i2c_master_send returned %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct regmap_config xrs700x_i2c_regmap_config = {
+	.val_bits = 16,
+	.reg_stride = 2,
+	.reg_bits = 32,
+	.pad_bits = 0,
+	.write_flag_mask = 0,
+	.read_flag_mask = 0,
+	.reg_read = xrs700x_i2c_reg_read,
+	.reg_write = xrs700x_i2c_reg_write,
+	.max_register = 0,
+	.cache_type = REGCACHE_NONE,
+	.reg_format_endian = REGMAP_ENDIAN_BIG,
+	.val_format_endian = REGMAP_ENDIAN_BIG
+};
+
+static int xrs700x_i2c_probe(struct i2c_client *i2c,
+			     const struct i2c_device_id *i2c_id)
+{
+	struct xrs700x *priv;
+	int ret;
+
+	priv = xrs700x_switch_alloc(&i2c->dev, i2c);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->regmap = devm_regmap_init(&i2c->dev, NULL, &i2c->dev,
+					&xrs700x_i2c_regmap_config);
+	if (IS_ERR(priv->regmap)) {
+		ret = PTR_ERR(priv->regmap);
+		dev_err(&i2c->dev, "Failed to initialize regmap: %d\n", ret);
+		return ret;
+	}
+
+	i2c_set_clientdata(i2c, priv);
+
+	ret = xrs700x_switch_register(priv);
+
+	/* Main DSA driver may not be started yet. */
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int xrs700x_i2c_remove(struct i2c_client *i2c)
+{
+	struct xrs700x *priv = i2c_get_clientdata(i2c);
+
+	xrs700x_switch_remove(priv);
+
+	return 0;
+}
+
+static const struct i2c_device_id xrs700x_i2c_id[] = {
+	{ "xrs700x-switch", 0 },
+	{},
+};
+
+MODULE_DEVICE_TABLE(i2c, xrs700x_i2c_id);
+
+static const struct of_device_id xrs700x_i2c_dt_ids[] = {
+	{ .compatible = "arrow,xrs7003e", .data = &xrs7003e_info },
+	{ .compatible = "arrow,xrs7003f", .data = &xrs7003f_info },
+	{ .compatible = "arrow,xrs7004e", .data = &xrs7004e_info },
+	{ .compatible = "arrow,xrs7004f", .data = &xrs7004f_info },
+	{},
+};
+MODULE_DEVICE_TABLE(of, xrs700x_i2c_dt_ids);
+
+static struct i2c_driver xrs700x_i2c_driver = {
+	.driver = {
+		.name	= "xrs700x-i2c",
+		.of_match_table = of_match_ptr(xrs700x_i2c_dt_ids),
+	},
+	.probe	= xrs700x_i2c_probe,
+	.remove	= xrs700x_i2c_remove,
+	.id_table = xrs700x_i2c_id,
+};
+
+module_i2c_driver(xrs700x_i2c_driver);
+
+MODULE_AUTHOR("George McCollister <george.mccollister@gmail.com>");
+MODULE_DESCRIPTION("Arrow SpeedChips XRS700x DSA I2C driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/net/dsa/xrs700x/xrs700x_mdio.c b/drivers/net/dsa/xrs700x/xrs700x_mdio.c
new file mode 100644
index 000000000000..a10ee28eb86e
--- /dev/null
+++ b/drivers/net/dsa/xrs700x/xrs700x_mdio.c
@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 NovaTech LLC
+ * George McCollister <george.mccollister@gmail.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/mdio.h>
+#include <linux/module.h>
+#include <linux/phy.h>
+#include <linux/if_vlan.h>
+#include "xrs700x.h"
+#include "xrs700x_reg.h"
+
+#define XRS_MDIO_IBA0	0x10
+#define XRS_MDIO_IBA1	0x11
+#define XRS_MDIO_IBD	0x14
+
+#define XRS_IB_READ	0x0
+#define XRS_IB_WRITE	0x1
+
+static int xrs700x_mdio_reg_read(void *context, unsigned int reg,
+				 unsigned int *val)
+{
+	struct mdio_device *mdiodev = context;
+	struct device *dev = &mdiodev->dev;
+	u16 uval;
+	int ret;
+
+	uval = (u16)FIELD_GET(GENMASK(31, 16), reg);
+
+	ret = mdiobus_write(mdiodev->bus, mdiodev->addr, XRS_MDIO_IBA1, uval);
+	if (ret < 0) {
+		dev_err(dev, "xrs mdiobus_write returned %d\n", ret);
+		return ret;
+	}
+
+	uval = (u16)((reg & GENMASK(15, 1)) | XRS_IB_READ);
+
+	ret = mdiobus_write(mdiodev->bus, mdiodev->addr, XRS_MDIO_IBA0, uval);
+	if (ret < 0) {
+		dev_err(dev, "xrs mdiobus_write returned %d\n", ret);
+		return ret;
+	}
+
+	ret = mdiobus_read(mdiodev->bus, mdiodev->addr, XRS_MDIO_IBD);
+	if (ret < 0) {
+		dev_err(dev, "xrs mdiobus_read returned %d\n", ret);
+		return ret;
+	}
+
+	*val = (unsigned int)ret;
+
+	return 0;
+}
+
+static int xrs700x_mdio_reg_write(void *context, unsigned int reg,
+				  unsigned int val)
+{
+	struct mdio_device *mdiodev = context;
+	struct device *dev = &mdiodev->dev;
+	u16 uval;
+	int ret;
+
+	ret = mdiobus_write(mdiodev->bus, mdiodev->addr, XRS_MDIO_IBD, (u16)val);
+	if (ret < 0) {
+		dev_err(dev, "xrs mdiobus_write returned %d\n", ret);
+		return ret;
+	}
+
+	uval = (u16)FIELD_GET(GENMASK(31, 16), reg);
+
+	ret = mdiobus_write(mdiodev->bus, mdiodev->addr, XRS_MDIO_IBA1, uval);
+	if (ret < 0) {
+		dev_err(dev, "xrs mdiobus_write returned %d\n", ret);
+		return ret;
+	}
+
+	uval = (u16)((reg & GENMASK(15, 1)) | XRS_IB_WRITE);
+
+	ret = mdiobus_write(mdiodev->bus, mdiodev->addr, XRS_MDIO_IBA0, uval);
+	if (ret < 0) {
+		dev_err(dev, "xrs mdiobus_write returned %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct regmap_config xrs700x_mdio_regmap_config = {
+	.val_bits = 16,
+	.reg_stride = 2,
+	.reg_bits = 32,
+	.pad_bits = 0,
+	.write_flag_mask = 0,
+	.read_flag_mask = 0,
+	.reg_read = xrs700x_mdio_reg_read,
+	.reg_write = xrs700x_mdio_reg_write,
+	.max_register = XRS_VLAN(VLAN_N_VID - 1),
+	.cache_type = REGCACHE_NONE,
+	.reg_format_endian = REGMAP_ENDIAN_BIG,
+	.val_format_endian = REGMAP_ENDIAN_BIG
+};
+
+static int xrs700x_mdio_probe(struct mdio_device *mdiodev)
+{
+	struct xrs700x *priv;
+	int ret;
+
+	priv = xrs700x_switch_alloc(&mdiodev->dev, mdiodev);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->regmap = devm_regmap_init(&mdiodev->dev, NULL, mdiodev,
+					&xrs700x_mdio_regmap_config);
+	if (IS_ERR(priv->regmap)) {
+		ret = PTR_ERR(priv->regmap);
+		dev_err(&mdiodev->dev, "Failed to initialize regmap: %d\n", ret);
+		return ret;
+	}
+
+	dev_set_drvdata(&mdiodev->dev, priv);
+
+	ret = xrs700x_switch_register(priv);
+
+	/* Main DSA driver may not be started yet. */
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static void xrs700x_mdio_remove(struct mdio_device *mdiodev)
+{
+	struct xrs700x *priv = dev_get_drvdata(&mdiodev->dev);
+
+	xrs700x_switch_remove(priv);
+}
+
+static const struct of_device_id xrs700x_mdio_dt_ids[] = {
+	{ .compatible = "arrow,xrs7003e", .data = &xrs7003e_info },
+	{ .compatible = "arrow,xrs7003f", .data = &xrs7003f_info },
+	{ .compatible = "arrow,xrs7004e", .data = &xrs7004e_info },
+	{ .compatible = "arrow,xrs7004f", .data = &xrs7004f_info },
+	{},
+};
+MODULE_DEVICE_TABLE(of, xrs700x_mdio_dt_ids);
+
+static struct mdio_driver xrs700x_mdio_driver = {
+	.mdiodrv.driver = {
+		.name	= "xrs700x-mdio",
+		.of_match_table = xrs700x_mdio_dt_ids,
+	},
+	.probe	= xrs700x_mdio_probe,
+	.remove	= xrs700x_mdio_remove,
+};
+
+mdio_module_driver(xrs700x_mdio_driver);
+
+MODULE_AUTHOR("George McCollister <george.mccollister@gmail.com>");
+MODULE_DESCRIPTION("Arrow SpeedChips XRS700x DSA MDIO driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/net/dsa/xrs700x/xrs700x_reg.h b/drivers/net/dsa/xrs700x/xrs700x_reg.h
new file mode 100644
index 000000000000..a135d4d92b6d
--- /dev/null
+++ b/drivers/net/dsa/xrs700x/xrs700x_reg.h
@@ -0,0 +1,203 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/* Register Base Addresses */
+#define XRS_DEVICE_ID_BASE		0x0
+#define XRS_GPIO_BASE			0x10000
+#define XRS_PORT_OFFSET			0x10000
+#define XRS_PORT_BASE(x)		(0x200000 + XRS_PORT_OFFSET * (x))
+#define XRS_RTC_BASE			0x280000
+#define XRS_TS_OFFSET			0x8000
+#define XRS_TS_BASE(x)			(0x290000 + XRS_TS_OFFSET * (x))
+#define XRS_SWITCH_CONF_BASE		0x300000
+
+/* Device Identification Registers */
+#define XRS_DEV_ID0			(XRS_DEVICE_ID_BASE + 0)
+#define XRS_DEV_ID1			(XRS_DEVICE_ID_BASE + 2)
+#define XRS_INT_ID0			(XRS_DEVICE_ID_BASE + 4)
+#define XRS_INT_ID1			(XRS_DEVICE_ID_BASE + 6)
+#define XRS_REV_ID			(XRS_DEVICE_ID_BASE + 8)
+
+/* GPIO Registers */
+#define XRS_CONFIG0			(XRS_GPIO_BASE + 0x1000)
+#define XRS_INPUT_STATUS0		(XRS_GPIO_BASE + 0x1002)
+#define XRS_CONFIG1			(XRS_GPIO_BASE + 0x1004)
+#define XRS_INPUT_STATUS1		(XRS_GPIO_BASE + 0x1006)
+#define XRS_CONFIG2			(XRS_GPIO_BASE + 0x1008)
+#define XRS_INPUT_STATUS2		(XRS_GPIO_BASE + 0x100a)
+
+/* Port Configuration Registers */
+#define XRS_PORT_GEN_BASE(x)		(XRS_PORT_BASE(x) + 0x0)
+#define XRS_PORT_HSR_BASE(x)		(XRS_PORT_BASE(x) + 0x2000)
+#define XRS_PORT_PTP_BASE(x)		(XRS_PORT_BASE(x) + 0x4000)
+#define XRS_PORT_CNT_BASE(x)		(XRS_PORT_BASE(x) + 0x6000)
+#define XRS_PORT_IPO_BASE(x)		(XRS_PORT_BASE(x) + 0x8000)
+
+/* Port Configuration Registers - General and State */
+#define XRS_PORT_STATE(x)		(XRS_PORT_GEN_BASE(x) + 0x0)
+#define XRS_PORT_FORWARDING		0
+#define XRS_PORT_LEARNING		1
+#define XRS_PORT_DISABLED		2
+#define XRS_PORT_MODE_NORMAL		0
+#define XRS_PORT_MODE_MANAGEMENT	1
+#define XRS_PORT_SPEED_1000		0x12
+#define XRS_PORT_SPEED_100		0x20
+#define XRS_PORT_SPEED_10		0x30
+#define XRS_PORT_VLAN(x)		(XRS_PORT_GEN_BASE(x) + 0x10)
+#define XRS_PORT_VLAN0_MAPPING(x)	(XRS_PORT_GEN_BASE(x) + 0x12)
+#define XRS_PORT_FWD_MASK(x)		(XRS_PORT_GEN_BASE(x) + 0x14)
+#define XRS_PORT_VLAN_PRIO(x)		(XRS_PORT_GEN_BASE(x) + 0x16)
+
+/* Port Configuration Registers - HSR/PRP */
+#define XRS_HSR_CFG(x)			(XRS_PORT_HSR_BASE(x) + 0x0)
+
+/* Port Configuration Registers - PTP */
+#define XRS_PTP_RX_SYNC_DELAY_NS_LO(x)	(XRS_PORT_PTP_BASE(x) + 0x2)
+#define XRS_PTP_RX_SYNC_DELAY_NS_HI(x)	(XRS_PORT_PTP_BASE(x) + 0x4)
+#define XRS_PTP_RX_EVENT_DELAY_NS(x)	(XRS_PORT_PTP_BASE(x) + 0xa)
+#define XRS_PTP_TX_EVENT_DELAY_NS(x)	(XRS_PORT_PTP_BASE(x) + 0x12)
+
+/* Port Configuration Registers - Counter */
+#define XRS_CNT_CTRL(x)			(XRS_PORT_CNT_BASE(x) + 0x0)
+#define XRS_RX_GOOD_OCTETS_L		(XRS_PORT_CNT_BASE(0) + 0x200)
+#define XRS_RX_GOOD_OCTETS_H		(XRS_PORT_CNT_BASE(0) + 0x202)
+#define XRS_RX_BAD_OCTETS_L		(XRS_PORT_CNT_BASE(0) + 0x204)
+#define XRS_RX_BAD_OCTETS_H		(XRS_PORT_CNT_BASE(0) + 0x206)
+#define XRS_RX_UNICAST_L		(XRS_PORT_CNT_BASE(0) + 0x208)
+#define XRS_RX_UNICAST_H		(XRS_PORT_CNT_BASE(0) + 0x20a)
+#define XRS_RX_BROADCAST_L		(XRS_PORT_CNT_BASE(0) + 0x20c)
+#define XRS_RX_BROADCAST_H		(XRS_PORT_CNT_BASE(0) + 0x20e)
+#define XRS_RX_MULTICAST_L		(XRS_PORT_CNT_BASE(0) + 0x210)
+#define XRS_RX_MULTICAST_H		(XRS_PORT_CNT_BASE(0) + 0x212)
+#define XRS_RX_UNDERSIZE_L		(XRS_PORT_CNT_BASE(0) + 0x214)
+#define XRS_RX_UNDERSIZE_H		(XRS_PORT_CNT_BASE(0) + 0x216)
+#define XRS_RX_FRAGMENTS_L		(XRS_PORT_CNT_BASE(0) + 0x218)
+#define XRS_RX_FRAGMENTS_H		(XRS_PORT_CNT_BASE(0) + 0x21a)
+#define XRS_RX_OVERSIZE_L		(XRS_PORT_CNT_BASE(0) + 0x21c)
+#define XRS_RX_OVERSIZE_H		(XRS_PORT_CNT_BASE(0) + 0x21e)
+#define XRS_RX_JABBER_L			(XRS_PORT_CNT_BASE(0) + 0x220)
+#define XRS_RX_JABBER_H			(XRS_PORT_CNT_BASE(0) + 0x222)
+#define XRS_RX_ERR_L			(XRS_PORT_CNT_BASE(0) + 0x224)
+#define XRS_RX_ERR_H			(XRS_PORT_CNT_BASE(0) + 0x226)
+#define XRS_RX_CRC_L			(XRS_PORT_CNT_BASE(0) + 0x228)
+#define XRS_RX_CRC_H			(XRS_PORT_CNT_BASE(0) + 0x22a)
+#define XRS_RX_64_L			(XRS_PORT_CNT_BASE(0) + 0x22c)
+#define XRS_RX_64_H			(XRS_PORT_CNT_BASE(0) + 0x22e)
+#define XRS_RX_65_127_L			(XRS_PORT_CNT_BASE(0) + 0x230)
+#define XRS_RX_65_127_H			(XRS_PORT_CNT_BASE(0) + 0x232)
+#define XRS_RX_128_255_L		(XRS_PORT_CNT_BASE(0) + 0x234)
+#define XRS_RX_128_255_H		(XRS_PORT_CNT_BASE(0) + 0x236)
+#define XRS_RX_256_511_L		(XRS_PORT_CNT_BASE(0) + 0x238)
+#define XRS_RX_256_511_H		(XRS_PORT_CNT_BASE(0) + 0x23a)
+#define XRS_RX_512_1023_L		(XRS_PORT_CNT_BASE(0) + 0x23c)
+#define XRS_RX_512_1023_H		(XRS_PORT_CNT_BASE(0) + 0x23e)
+#define XRS_RX_1024_1536_L		(XRS_PORT_CNT_BASE(0) + 0x240)
+#define XRS_RX_1024_1536_H		(XRS_PORT_CNT_BASE(0) + 0x242)
+#define XRS_RX_HSR_PRP_L		(XRS_PORT_CNT_BASE(0) + 0x244)
+#define XRS_RX_HSR_PRP_H		(XRS_PORT_CNT_BASE(0) + 0x246)
+#define XRS_RX_WRONGLAN_L		(XRS_PORT_CNT_BASE(0) + 0x248)
+#define XRS_RX_WRONGLAN_H		(XRS_PORT_CNT_BASE(0) + 0x24a)
+#define XRS_RX_DUPLICATE_L		(XRS_PORT_CNT_BASE(0) + 0x24c)
+#define XRS_RX_DUPLICATE_H		(XRS_PORT_CNT_BASE(0) + 0x24e)
+#define XRS_TX_OCTETS_L			(XRS_PORT_CNT_BASE(0) + 0x280)
+#define XRS_TX_OCTETS_H			(XRS_PORT_CNT_BASE(0) + 0x282)
+#define XRS_TX_UNICAST_L		(XRS_PORT_CNT_BASE(0) + 0x284)
+#define XRS_TX_UNICAST_H		(XRS_PORT_CNT_BASE(0) + 0x286)
+#define XRS_TX_BROADCAST_L		(XRS_PORT_CNT_BASE(0) + 0x288)
+#define XRS_TX_BROADCAST_H		(XRS_PORT_CNT_BASE(0) + 0x28a)
+#define XRS_TX_MULTICAST_L		(XRS_PORT_CNT_BASE(0) + 0x28c)
+#define XRS_TX_MULTICAST_H		(XRS_PORT_CNT_BASE(0) + 0x28e)
+#define XRS_TX_HSR_PRP_L		(XRS_PORT_CNT_BASE(0) + 0x290)
+#define XRS_TX_HSR_PRP_H		(XRS_PORT_CNT_BASE(0) + 0x292)
+#define XRS_PRIQ_DROP_L			(XRS_PORT_CNT_BASE(0) + 0x2c0)
+#define XRS_PRIQ_DROP_H			(XRS_PORT_CNT_BASE(0) + 0x2c2)
+#define XRS_EARLY_DROP_L		(XRS_PORT_CNT_BASE(0) + 0x2c4)
+#define XRS_EARLY_DROP_H		(XRS_PORT_CNT_BASE(0) + 0x2c6)
+
+/* Port Configuration Registers - Inbound Policy 0 - 15 */
+#define XRS_ETH_ADDR_CFG(x, p)		(XRS_PORT_IPO_BASE(x) + \
+					 (p) * 0x20 + 0x0)
+#define XRS_ETH_ADDR_FWD_ALLOW(x, p)	(XRS_PORT_IPO_BASE(x) + \
+					 (p) * 0x20 + 0x2)
+#define XRS_ETH_ADDR_FWD_MIRROR(x, p)	(XRS_PORT_IPO_BASE(x) + \
+					 (p) * 0x20 + 0x4)
+#define XRS_ETH_ADDR_0(x, p)		(XRS_PORT_IPO_BASE(x) + \
+					 (p) * 0x20 + 0x8)
+#define XRS_ETH_ADDR_1(x, p)		(XRS_PORT_IPO_BASE(x) + \
+					 (p) * 0x20 + 0xa)
+#define XRS_ETH_ADDR_2(x, p)		(XRS_PORT_IPO_BASE(x) + \
+					 (p) * 0x20 + 0xc)
+
+/* RTC Registers */
+#define XRS_CUR_NSEC0			(XRS_RTC_BASE + 0x1004)
+#define XRS_CUR_NSEC1			(XRS_RTC_BASE + 0x1006)
+#define XRS_CUR_SEC0			(XRS_RTC_BASE + 0x1008)
+#define XRS_CUR_SEC1			(XRS_RTC_BASE + 0x100a)
+#define XRS_CUR_SEC2			(XRS_RTC_BASE + 0x100c)
+#define XRS_TIME_CC0			(XRS_RTC_BASE + 0x1010)
+#define XRS_TIME_CC1			(XRS_RTC_BASE + 0x1012)
+#define XRS_TIME_CC2			(XRS_RTC_BASE + 0x1014)
+#define XRS_STEP_SIZE0			(XRS_RTC_BASE + 0x1020)
+#define XRS_STEP_SIZE1			(XRS_RTC_BASE + 0x1022)
+#define XRS_STEP_SIZE2			(XRS_RTC_BASE + 0x1024)
+#define XRS_ADJUST_NSEC0		(XRS_RTC_BASE + 0x1034)
+#define XRS_ADJUST_NSEC1		(XRS_RTC_BASE + 0x1036)
+#define XRS_ADJUST_SEC0			(XRS_RTC_BASE + 0x1038)
+#define XRS_ADJUST_SEC1			(XRS_RTC_BASE + 0x103a)
+#define XRS_ADJUST_SEC2			(XRS_RTC_BASE + 0x103c)
+#define XRS_TIME_CMD			(XRS_RTC_BASE + 0x1040)
+
+/* Time Stamper Registers */
+#define XRS_TS_CTRL(x)			(XRS_TS_BASE(x) + 0x1000)
+#define XRS_TS_INT_MASK(x)		(XRS_TS_BASE(x) + 0x1008)
+#define XRS_TS_INT_STATUS(x)		(XRS_TS_BASE(x) + 0x1010)
+#define XRS_TS_NSEC0(x)			(XRS_TS_BASE(x) + 0x1104)
+#define XRS_TS_NSEC1(x)			(XRS_TS_BASE(x) + 0x1106)
+#define XRS_TS_SEC0(x)			(XRS_TS_BASE(x) + 0x1108)
+#define XRS_TS_SEC1(x)			(XRS_TS_BASE(x) + 0x110a)
+#define XRS_TS_SEC2(x)			(XRS_TS_BASE(x) + 0x110c)
+#define XRS_PNCT0(x)			(XRS_TS_BASE(x) + 0x1110)
+#define XRS_PNCT1(x)			(XRS_TS_BASE(x) + 0x1112)
+
+/* Switch Configuration Registers */
+#define XRS_SWITCH_GEN_BASE		(XRS_SWITCH_CONF_BASE + 0x0)
+#define XRS_SWITCH_TS_BASE		(XRS_SWITCH_CONF_BASE + 0x2000)
+#define XRS_SWITCH_VLAN_BASE		(XRS_SWITCH_CONF_BASE + 0x4000)
+
+/* Switch Configuration Registers - General */
+#define XRS_GENERAL			(XRS_SWITCH_GEN_BASE + 0x10)
+#define XRS_GENERAL_TIME_TRAILER	BIT(9)
+#define XRS_GENERAL_MOD_SYNC		BIT(10)
+#define XRS_GENERAL_CUT_THRU		BIT(13)
+#define XRS_GENERAL_CLR_MAC_TBL		BIT(14)
+#define XRS_GENERAL_RESET		BIT(15)
+#define XRS_MT_CLEAR_MASK		(XRS_SWITCH_GEN_BASE + 0x12)
+#define XRS_ADDRESS_AGING		(XRS_SWITCH_GEN_BASE + 0x20)
+#define XRS_TS_CTRL_TX			(XRS_SWITCH_GEN_BASE + 0x28)
+#define XRS_TS_CTRL_RX			(XRS_SWITCH_GEN_BASE + 0x2a)
+#define XRS_INT_MASK			(XRS_SWITCH_GEN_BASE + 0x2c)
+#define XRS_INT_STATUS			(XRS_SWITCH_GEN_BASE + 0x2e)
+#define XRS_MAC_TABLE0			(XRS_SWITCH_GEN_BASE + 0x200)
+#define XRS_MAC_TABLE1			(XRS_SWITCH_GEN_BASE + 0x202)
+#define XRS_MAC_TABLE2			(XRS_SWITCH_GEN_BASE + 0x204)
+#define XRS_MAC_TABLE3			(XRS_SWITCH_GEN_BASE + 0x206)
+
+/* Switch Configuration Registers - Frame Timestamp */
+#define XRS_TX_TS_NS_LO(t)		(XRS_SWITCH_TS_BASE + 0x80 * (t) + 0x0)
+#define XRS_TX_TS_NS_HI(t)		(XRS_SWITCH_TS_BASE + 0x80 * (t) + 0x2)
+#define XRS_TX_TS_S_LO(t)		(XRS_SWITCH_TS_BASE + 0x80 * (t) + 0x4)
+#define XRS_TX_TS_S_HI(t)		(XRS_SWITCH_TS_BASE + 0x80 * (t) + 0x6)
+#define XRS_TX_TS_HDR(t, h)		(XRS_SWITCH_TS_BASE + 0x80 * (t) + \
+					 0x2 * (h) + 0xe)
+#define XRS_RX_TS_NS_LO(t)		(XRS_SWITCH_TS_BASE + 0x80 * (t) + \
+					 0x200)
+#define XRS_RX_TS_NS_HI(t)		(XRS_SWITCH_TS_BASE + 0x80 * (t) + \
+					 0x202)
+#define XRS_RX_TS_S_LO(t)		(XRS_SWITCH_TS_BASE + 0x80 * (t) + \
+					 0x204)
+#define XRS_RX_TS_S_HI(t)		(XRS_SWITCH_TS_BASE + 0x80 * (t) + \
+					 0x206)
+#define XRS_RX_TS_HDR(t, h)		(XRS_SWITCH_TS_BASE + 0x80 * (t) + \
+					 0x2 * (h) + 0xe)
+
+/* Switch Configuration Registers - VLAN */
+#define XRS_VLAN(v)			(XRS_SWITCH_VLAN_BASE + 0x2 * (v))
diff --git a/include/net/dsa.h b/include/net/dsa.h
index 06e3784ec55c..fa537afcab53 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -46,6 +46,7 @@ struct phylink_link_state;
 #define DSA_TAG_PROTO_AR9331_VALUE		16
 #define DSA_TAG_PROTO_RTL4_A_VALUE		17
 #define DSA_TAG_PROTO_HELLCREEK_VALUE		18
+#define DSA_TAG_PROTO_XRS700X_VALUE		19
 
 enum dsa_tag_protocol {
 	DSA_TAG_PROTO_NONE		= DSA_TAG_PROTO_NONE_VALUE,
@@ -67,6 +68,7 @@ enum dsa_tag_protocol {
 	DSA_TAG_PROTO_AR9331		= DSA_TAG_PROTO_AR9331_VALUE,
 	DSA_TAG_PROTO_RTL4_A		= DSA_TAG_PROTO_RTL4_A_VALUE,
 	DSA_TAG_PROTO_HELLCREEK		= DSA_TAG_PROTO_HELLCREEK_VALUE,
+	DSA_TAG_PROTO_XRS700X		= DSA_TAG_PROTO_XRS700X_VALUE,
 };
 
 struct packet_type;
diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig
index dfecd7b22fd7..2d226a5c085f 100644
--- a/net/dsa/Kconfig
+++ b/net/dsa/Kconfig
@@ -139,4 +139,10 @@ config NET_DSA_TAG_TRAILER
 	  Say Y or M if you want to enable support for tagging frames at
 	  with a trailed. e.g. Marvell 88E6060.
 
+config NET_DSA_TAG_XRS700X
+	tristate "Tag driver for XRS700x switches"
+	help
+	  Say Y or M if you want to enable support for tagging frames for
+	  Arrow SpeedChips XRS700x switches that use a single byte tag trailer.
+
 endif
diff --git a/net/dsa/Makefile b/net/dsa/Makefile
index 0fb2b75a7ae3..92cea2132241 100644
--- a/net/dsa/Makefile
+++ b/net/dsa/Makefile
@@ -18,3 +18,4 @@ obj-$(CONFIG_NET_DSA_TAG_OCELOT) += tag_ocelot.o
 obj-$(CONFIG_NET_DSA_TAG_QCA) += tag_qca.o
 obj-$(CONFIG_NET_DSA_TAG_SJA1105) += tag_sja1105.o
 obj-$(CONFIG_NET_DSA_TAG_TRAILER) += tag_trailer.o
+obj-$(CONFIG_NET_DSA_TAG_XRS700X) += tag_xrs700x.o
diff --git a/net/dsa/tag_xrs700x.c b/net/dsa/tag_xrs700x.c
new file mode 100644
index 000000000000..db0ed1a5fcb7
--- /dev/null
+++ b/net/dsa/tag_xrs700x.c
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * XRS700x tag format handling
+ * Copyright (c) 2008-2009 Marvell Semiconductor
+ * Copyright (c) 2020 NovaTech LLC
+ */
+
+#include <linux/bitops.h>
+
+#include "dsa_priv.h"
+
+static struct sk_buff *xrs700x_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct dsa_port *dp = dsa_slave_to_port(dev);
+	u8 *trailer;
+
+	trailer = skb_put(skb, 1);
+	trailer[0] = BIT(dp->index);
+
+	return skb;
+}
+
+static struct sk_buff *xrs700x_rcv(struct sk_buff *skb, struct net_device *dev,
+				   struct packet_type *pt)
+{
+	int source_port;
+	u8 *trailer;
+
+	trailer = skb_tail_pointer(skb) - 1;
+
+	source_port = ffs((int)trailer[0]) - 1;
+
+	if (source_port < 0)
+		return NULL;
+
+	skb->dev = dsa_master_find_slave(dev, 0, source_port);
+	if (!skb->dev)
+		return NULL;
+
+	if (pskb_trim_rcsum(skb, skb->len - 1))
+		return NULL;
+
+	/* Frame is forwarded by hardware, don't forward in software. */
+	skb->offload_fwd_mark = 1;
+
+	return skb;
+}
+
+static const struct dsa_device_ops xrs700x_netdev_ops = {
+	.name	= "xrs700x",
+	.proto	= DSA_TAG_PROTO_XRS700X,
+	.xmit	= xrs700x_xmit,
+	.rcv	= xrs700x_rcv,
+	.overhead = 1,
+	.tail_tag = true,
+};
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_XRS700X);
+
+module_dsa_tag_driver(xrs700x_netdev_ops);