Merge branch 'add-dsa-switch-support-for-ar9331'

Oleksij Rempel says:

====================
add dsa switch support for ar9331

changes v6:
- remove ag71xx changes from this patch set. It needs more work.
- ar9331: fix register definition and add ASCII art switch documentation.

changes v6:
- rebase against net-next

changes v5:
- remote support for port5. The effort of using this port is
  questionable. Currently, it is better to not use it at all, then
  adding buggy support.
- remove port enable call back. There is nothing what we actually need
  to enable.
- rebase it against v5.5-rc1

changes v4:
- ag71xx: ag71xx_mac_validate fix always false comparison (&& -> ||)
- tag_ar9331: use skb_pull_rcsum() instead of skb_pull().
- tag_ar9331: drop skb_set_mac_header()

changes v3:
- ag71xx: ag71xx_mac_config: ignore MLO_AN_INBAND mode. It is not
  supported by HW and SW.
- ag71xx: ag71xx_mac_validate: return all supported bits on
  PHY_INTERFACE_MODE_NA

changes v2:
- move Atheros AR9331 TAG format to separate patch
- use netdev_warn_once in the tag driver to reduce potential message spam
- typo fixes
- reorder tag driver alphabetically
- configure switch to maximal frame size
- use mdiobus_read/write
- fail if mdio sub node is not found
- add comment for post reset state
- remove deprecated comment about device id
- remove phy-handle option for node with fixed-link
- ag71xx: set 1G support only for GMII mode

This patch series provides dsa switch support for Atheros ar9331 WiSoC.
As side effect ag71xx needed to be ported to phylink to make the switch
driver (as well phylink based) work properly.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

12 files changed, 1253 insertions, 1 deletions

diff --git a/Documentation/devicetree/bindings/net/dsa/ar9331.txt b/Documentation/devicetree/bindings/net/dsa/ar9331.txt
new file mode 100644
index 000000000000..320607cbbb17
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/dsa/ar9331.txt
@@ -0,0 +1,148 @@
+Atheros AR9331 built-in switch
+=============================
+
+It is a switch built-in to Atheros AR9331 WiSoC and addressable over internal
+MDIO bus. All PHYs are built-in as well.
+
+Required properties:
+
+ - compatible: should be: "qca,ar9331-switch"
+ - reg: Address on the MII bus for the switch.
+ - resets : Must contain an entry for each entry in reset-names.
+ - reset-names : Must include the following entries: "switch"
+ - interrupt-parent: Phandle to the parent interrupt controller
+ - interrupts: IRQ line for the switch
+ - interrupt-controller: Indicates the switch is itself an interrupt
+   controller. This is used for the PHY interrupts.
+ - #interrupt-cells: must be 1
+ - mdio: Container of PHY and devices on the switches MDIO bus.
+
+See Documentation/devicetree/bindings/net/dsa/dsa.txt for a list of additional
+required and optional properties.
+Examples:
+
+eth0: ethernet@19000000 {
+	compatible = "qca,ar9330-eth";
+	reg = <0x19000000 0x200>;
+	interrupts = <4>;
+
+	resets = <&rst 9>, <&rst 22>;
+	reset-names = "mac", "mdio";
+	clocks = <&pll ATH79_CLK_AHB>, <&pll ATH79_CLK_AHB>;
+	clock-names = "eth", "mdio";
+
+	phy-mode = "mii";
+	phy-handle = <&phy_port4>;
+};
+
+eth1: ethernet@1a000000 {
+	compatible = "qca,ar9330-eth";
+	reg = <0x1a000000 0x200>;
+	interrupts = <5>;
+	resets = <&rst 13>, <&rst 23>;
+	reset-names = "mac", "mdio";
+	clocks = <&pll ATH79_CLK_AHB>, <&pll ATH79_CLK_AHB>;
+	clock-names = "eth", "mdio";
+
+	phy-mode = "gmii";
+
+	fixed-link {
+		speed = <1000>;
+		full-duplex;
+	};
+
+	mdio {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		switch10: switch@10 {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			compatible = "qca,ar9331-switch";
+			reg = <0x10>;
+			resets = <&rst 8>;
+			reset-names = "switch";
+
+			interrupt-parent = <&miscintc>;
+			interrupts = <12>;
+
+			interrupt-controller;
+			#interrupt-cells = <1>;
+
+			ports {
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				switch_port0: port@0 {
+					reg = <0x0>;
+					label = "cpu";
+					ethernet = <&eth1>;
+
+					phy-mode = "gmii";
+
+					fixed-link {
+						speed = <1000>;
+						full-duplex;
+					};
+				};
+
+				switch_port1: port@1 {
+					reg = <0x1>;
+					phy-handle = <&phy_port0>;
+					phy-mode = "internal";
+				};
+
+				switch_port2: port@2 {
+					reg = <0x2>;
+					phy-handle = <&phy_port1>;
+					phy-mode = "internal";
+				};
+
+				switch_port3: port@3 {
+					reg = <0x3>;
+					phy-handle = <&phy_port2>;
+					phy-mode = "internal";
+				};
+
+				switch_port4: port@4 {
+					reg = <0x4>;
+					phy-handle = <&phy_port3>;
+					phy-mode = "internal";
+				};
+			};
+
+			mdio {
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				interrupt-parent = <&switch10>;
+
+				phy_port0: phy@0 {
+					reg = <0x0>;
+					interrupts = <0>;
+				};
+
+				phy_port1: phy@1 {
+					reg = <0x1>;
+					interrupts = <0>;
+				};
+
+				phy_port2: phy@2 {
+					reg = <0x2>;
+					interrupts = <0>;
+				};
+
+				phy_port3: phy@3 {
+					reg = <0x3>;
+					interrupts = <0>;
+				};
+
+				phy_port4: phy@4 {
+					reg = <0x4>;
+					interrupts = <0>;
+				};
+			};
+		};
+	};
+};
diff --git a/arch/mips/boot/dts/qca/ar9331.dtsi b/arch/mips/boot/dts/qca/ar9331.dtsi
index 5cfc9d347826..8f5aed760abb 100644
--- a/arch/mips/boot/dts/qca/ar9331.dtsi
+++ b/arch/mips/boot/dts/qca/ar9331.dtsi
@@ -126,6 +126,9 @@
 			clocks = <&pll ATH79_CLK_AHB>, <&pll ATH79_CLK_AHB>;
 			clock-names = "eth", "mdio";
 
+			phy-mode = "mii";
+			phy-handle = <&phy_port4>;
+
 			status = "disabled";
 		};
 
@@ -133,13 +136,127 @@
 			compatible = "qca,ar9330-eth";
 			reg = <0x1a000000 0x200>;
 			interrupts = <5>;
-
 			resets = <&rst 13>, <&rst 23>;
 			reset-names = "mac", "mdio";
 			clocks = <&pll ATH79_CLK_AHB>, <&pll ATH79_CLK_AHB>;
 			clock-names = "eth", "mdio";
 
+			phy-mode = "gmii";
+
 			status = "disabled";
+
+			fixed-link {
+				speed = <1000>;
+				full-duplex;
+			};
+
+			mdio {
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				switch10: switch@10 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+
+					compatible = "qca,ar9331-switch";
+					reg = <0x10>;
+					resets = <&rst 8>;
+					reset-names = "switch";
+
+					interrupt-parent = <&miscintc>;
+					interrupts = <12>;
+
+					interrupt-controller;
+					#interrupt-cells = <1>;
+
+					ports {
+						#address-cells = <1>;
+						#size-cells = <0>;
+
+						switch_port0: port@0 {
+							reg = <0x0>;
+							label = "cpu";
+							ethernet = <&eth1>;
+
+							phy-mode = "gmii";
+
+							fixed-link {
+								speed = <1000>;
+								full-duplex;
+							};
+						};
+
+						switch_port1: port@1 {
+							reg = <0x1>;
+							phy-handle = <&phy_port0>;
+							phy-mode = "internal";
+
+							status = "disabled";
+						};
+
+						switch_port2: port@2 {
+							reg = <0x2>;
+							phy-handle = <&phy_port1>;
+							phy-mode = "internal";
+
+							status = "disabled";
+						};
+
+						switch_port3: port@3 {
+							reg = <0x3>;
+							phy-handle = <&phy_port2>;
+							phy-mode = "internal";
+
+							status = "disabled";
+						};
+
+						switch_port4: port@4 {
+							reg = <0x4>;
+							phy-handle = <&phy_port3>;
+							phy-mode = "internal";
+
+							status = "disabled";
+						};
+					};
+
+					mdio {
+						#address-cells = <1>;
+						#size-cells = <0>;
+
+						interrupt-parent = <&switch10>;
+
+						phy_port0: phy@0 {
+							reg = <0x0>;
+							interrupts = <0>;
+							status = "disabled";
+						};
+
+						phy_port1: phy@1 {
+							reg = <0x1>;
+							interrupts = <0>;
+							status = "disabled";
+						};
+
+						phy_port2: phy@2 {
+							reg = <0x2>;
+							interrupts = <0>;
+							status = "disabled";
+						};
+
+						phy_port3: phy@3 {
+							reg = <0x3>;
+							interrupts = <0>;
+							status = "disabled";
+						};
+
+						phy_port4: phy@4 {
+							reg = <0x4>;
+							interrupts = <0>;
+							status = "disabled";
+						};
+					};
+				};
+			};
 		};
 
 		usb: usb@1b000100 {
diff --git a/arch/mips/boot/dts/qca/ar9331_dpt_module.dts b/arch/mips/boot/dts/qca/ar9331_dpt_module.dts
index 77bab823eb3b..0f2b20044834 100644
--- a/arch/mips/boot/dts/qca/ar9331_dpt_module.dts
+++ b/arch/mips/boot/dts/qca/ar9331_dpt_module.dts
@@ -84,3 +84,16 @@
 &eth1 {
 	status = "okay";
 };
+
+&switch_port1 {
+	label = "lan0";
+	status = "okay";
+};
+
+&phy_port0 {
+	status = "okay";
+};
+
+&phy_port4 {
+	status = "okay";
+};
diff --git a/drivers/net/dsa/Kconfig b/drivers/net/dsa/Kconfig
index c7667645f04a..cbd74a72d0a1 100644
--- a/drivers/net/dsa/Kconfig
+++ b/drivers/net/dsa/Kconfig
@@ -54,6 +54,8 @@ source "drivers/net/dsa/mv88e6xxx/Kconfig"
 
 source "drivers/net/dsa/ocelot/Kconfig"
 
+source "drivers/net/dsa/qca/Kconfig"
+
 source "drivers/net/dsa/sja1105/Kconfig"
 
 config NET_DSA_QCA8K
diff --git a/drivers/net/dsa/Makefile b/drivers/net/dsa/Makefile
index 9d384a32b3a2..4a943ccc2ca4 100644
--- a/drivers/net/dsa/Makefile
+++ b/drivers/net/dsa/Makefile
@@ -21,4 +21,5 @@ obj-y				+= b53/
 obj-y				+= microchip/
 obj-y				+= mv88e6xxx/
 obj-y				+= ocelot/
+obj-y				+= qca/
 obj-y				+= sja1105/
diff --git a/drivers/net/dsa/qca/Kconfig b/drivers/net/dsa/qca/Kconfig
new file mode 100644
index 000000000000..e3c8d715a18f
--- /dev/null
+++ b/drivers/net/dsa/qca/Kconfig
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config NET_DSA_AR9331
+	tristate "Qualcomm Atheros AR9331 Ethernet switch support"
+	depends on NET_DSA
+	select NET_DSA_TAG_AR9331
+	select REGMAP
+	---help---
+	  This enables support for the Qualcomm Atheros AR9331 built-in Ethernet
+	  switch.
diff --git a/drivers/net/dsa/qca/Makefile b/drivers/net/dsa/qca/Makefile
new file mode 100644
index 000000000000..274022319066
--- /dev/null
+++ b/drivers/net/dsa/qca/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_NET_DSA_AR9331)	+= ar9331.o
diff --git a/drivers/net/dsa/qca/ar9331.c b/drivers/net/dsa/qca/ar9331.c
new file mode 100644
index 000000000000..0d1a7cd85fe8
--- /dev/null
+++ b/drivers/net/dsa/qca/ar9331.c
@@ -0,0 +1,855 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2019 Pengutronix, Oleksij Rempel <kernel@pengutronix.de>
+/*
+ *                   +----------------------+
+ * GMAC1----RGMII----|--MAC0                |
+ *      \---MDIO1----|--REGs                |----MDIO3----\
+ *                   |                      |             |  +------+
+ *                   |                      |             +--|      |
+ *                   |                 MAC1-|----RMII--M-----| PHY0 |-o P0
+ *                   |                      |          |  |  +------+
+ *                   |                      |          |  +--|      |
+ *                   |                 MAC2-|----RMII--------| PHY1 |-o P1
+ *                   |                      |          |  |  +------+
+ *                   |                      |          |  +--|      |
+ *                   |                 MAC3-|----RMII--------| PHY2 |-o P2
+ *                   |                      |          |  |  +------+
+ *                   |                      |          |  +--|      |
+ *                   |                 MAC4-|----RMII--------| PHY3 |-o P3
+ *                   |                      |          |  |  +------+
+ *                   |                      |          |  +--|      |
+ *                   |                 MAC5-|--+-RMII--M-----|-PHY4-|-o P4
+ *                   |                      |  |       |     +------+
+ *                   +----------------------+  |       \--CFG_SW_PHY_SWAP
+ * GMAC0---------------RMII--------------------/        \-CFG_SW_PHY_ADDR_SWAP
+ *      \---MDIO0--NC
+ *
+ * GMAC0 and MAC5 are connected together and use same PHY. Depending on
+ * configuration it can be PHY4 (default) or PHY0. Only GMAC0 or MAC5 can be
+ * used at same time. If GMAC0 is used (default) then MAC5 should be disabled.
+ *
+ * CFG_SW_PHY_SWAP - swap connections of PHY0 and PHY4. If this bit is not set
+ * PHY4 is connected to GMAC0/MAC5 bundle and PHY0 is connected to MAC1. If this
+ * bit is set, PHY4 is connected to MAC1 and PHY0 is connected to GMAC0/MAC5
+ * bundle.
+ *
+ * CFG_SW_PHY_ADDR_SWAP - swap addresses of PHY0 and PHY4
+ *
+ * CFG_SW_PHY_SWAP and CFG_SW_PHY_ADDR_SWAP are part of SoC specific register
+ * set and not related to switch internal registers.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/module.h>
+#include <linux/of_irq.h>
+#include <linux/of_mdio.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+#include <net/dsa.h>
+
+#define AR9331_SW_NAME				"ar9331_switch"
+#define AR9331_SW_PORTS				6
+
+/* dummy reg to change page */
+#define AR9331_SW_REG_PAGE			0x40000
+
+/* Global Interrupt */
+#define AR9331_SW_REG_GINT			0x10
+#define AR9331_SW_REG_GINT_MASK			0x14
+#define AR9331_SW_GINT_PHY_INT			BIT(2)
+
+#define AR9331_SW_REG_FLOOD_MASK		0x2c
+#define AR9331_SW_FLOOD_MASK_BROAD_TO_CPU	BIT(26)
+
+#define AR9331_SW_REG_GLOBAL_CTRL		0x30
+#define AR9331_SW_GLOBAL_CTRL_MFS_M		GENMASK(13, 0)
+
+#define AR9331_SW_REG_MDIO_CTRL			0x98
+#define AR9331_SW_MDIO_CTRL_BUSY		BIT(31)
+#define AR9331_SW_MDIO_CTRL_MASTER_EN		BIT(30)
+#define AR9331_SW_MDIO_CTRL_CMD_READ		BIT(27)
+#define AR9331_SW_MDIO_CTRL_PHY_ADDR_M		GENMASK(25, 21)
+#define AR9331_SW_MDIO_CTRL_REG_ADDR_M		GENMASK(20, 16)
+#define AR9331_SW_MDIO_CTRL_DATA_M		GENMASK(16, 0)
+
+#define AR9331_SW_REG_PORT_STATUS(_port)	(0x100 + (_port) * 0x100)
+
+/* FLOW_LINK_EN - enable mac flow control config auto-neg with phy.
+ * If not set, mac can be config by software.
+ */
+#define AR9331_SW_PORT_STATUS_FLOW_LINK_EN	BIT(12)
+
+/* LINK_EN - If set, MAC is configured from PHY link status.
+ * If not set, MAC should be configured by software.
+ */
+#define AR9331_SW_PORT_STATUS_LINK_EN		BIT(9)
+#define AR9331_SW_PORT_STATUS_DUPLEX_MODE	BIT(6)
+#define AR9331_SW_PORT_STATUS_RX_FLOW_EN	BIT(5)
+#define AR9331_SW_PORT_STATUS_TX_FLOW_EN	BIT(4)
+#define AR9331_SW_PORT_STATUS_RXMAC		BIT(3)
+#define AR9331_SW_PORT_STATUS_TXMAC		BIT(2)
+#define AR9331_SW_PORT_STATUS_SPEED_M		GENMASK(1, 0)
+#define AR9331_SW_PORT_STATUS_SPEED_1000	2
+#define AR9331_SW_PORT_STATUS_SPEED_100		1
+#define AR9331_SW_PORT_STATUS_SPEED_10		0
+
+#define AR9331_SW_PORT_STATUS_MAC_MASK \
+	(AR9331_SW_PORT_STATUS_TXMAC | AR9331_SW_PORT_STATUS_RXMAC)
+
+#define AR9331_SW_PORT_STATUS_LINK_MASK \
+	(AR9331_SW_PORT_STATUS_LINK_EN | AR9331_SW_PORT_STATUS_FLOW_LINK_EN | \
+	 AR9331_SW_PORT_STATUS_DUPLEX_MODE | \
+	 AR9331_SW_PORT_STATUS_RX_FLOW_EN | AR9331_SW_PORT_STATUS_TX_FLOW_EN | \
+	 AR9331_SW_PORT_STATUS_SPEED_M)
+
+/* Phy bypass mode
+ * ------------------------------------------------------------------------
+ * Bit:   | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 |11 |12 |13 |14 |15 |
+ *
+ * real   | start |   OP  | PhyAddr           |  Reg Addr         |  TA   |
+ * atheros| start |   OP  | 2'b00 |PhyAdd[2:0]|  Reg Addr[4:0]    |  TA   |
+ *
+ *
+ * Bit:   |16 |17 |18 |19 |20 |21 |22 |23 |24 |25 |26 |27 |28 |29 |30 |31 |
+ * real   |  Data                                                         |
+ * atheros|  Data                                                         |
+ *
+ * ------------------------------------------------------------------------
+ * Page address mode
+ * ------------------------------------------------------------------------
+ * Bit:   | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 |11 |12 |13 |14 |15 |
+ * real   | start |   OP  | PhyAddr           |  Reg Addr         |  TA   |
+ * atheros| start |   OP  | 2'b11 |                          8'b0 |  TA   |
+ *
+ * Bit:   |16 |17 |18 |19 |20 |21 |22 |23 |24 |25 |26 |27 |28 |29 |30 |31 |
+ * real   |  Data                                                         |
+ * atheros|                       | Page [9:0]                            |
+ */
+/* In case of Page Address mode, Bit[18:9] of 32 bit register address should be
+ * written to bits[9:0] of mdio data register.
+ */
+#define AR9331_SW_ADDR_PAGE			GENMASK(18, 9)
+
+/* ------------------------------------------------------------------------
+ * Normal register access mode
+ * ------------------------------------------------------------------------
+ * Bit:   | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 |11 |12 |13 |14 |15 |
+ * real   | start |   OP  | PhyAddr           |  Reg Addr         |  TA   |
+ * atheros| start |   OP  | 2'b10 |  low_addr[7:0]                |  TA   |
+ *
+ * Bit:   |16 |17 |18 |19 |20 |21 |22 |23 |24 |25 |26 |27 |28 |29 |30 |31 |
+ * real   |  Data                                                         |
+ * atheros|  Data                                                         |
+ * ------------------------------------------------------------------------
+ */
+#define AR9331_SW_LOW_ADDR_PHY			GENMASK(8, 6)
+#define AR9331_SW_LOW_ADDR_REG			GENMASK(5, 1)
+
+#define AR9331_SW_MDIO_PHY_MODE_M		GENMASK(4, 3)
+#define AR9331_SW_MDIO_PHY_MODE_PAGE		3
+#define AR9331_SW_MDIO_PHY_MODE_REG		2
+#define AR9331_SW_MDIO_PHY_MODE_BYPASS		0
+#define AR9331_SW_MDIO_PHY_ADDR_M		GENMASK(2, 0)
+
+/* Empirical determined values */
+#define AR9331_SW_MDIO_POLL_SLEEP_US		1
+#define AR9331_SW_MDIO_POLL_TIMEOUT_US		20
+
+struct ar9331_sw_priv {
+	struct device *dev;
+	struct dsa_switch ds;
+	struct dsa_switch_ops ops;
+	struct irq_domain *irqdomain;
+	struct mii_bus *mbus; /* mdio master */
+	struct mii_bus *sbus; /* mdio slave */
+	struct regmap *regmap;
+	struct reset_control *sw_reset;
+};
+
+/* Warning: switch reset will reset last AR9331_SW_MDIO_PHY_MODE_PAGE request
+ * If some kind of optimization is used, the request should be repeated.
+ */
+static int ar9331_sw_reset(struct ar9331_sw_priv *priv)
+{
+	int ret;
+
+	ret = reset_control_assert(priv->sw_reset);
+	if (ret)
+		goto error;
+
+	/* AR9331 doc do not provide any information about proper reset
+	 * sequence. The AR8136 (the closes switch to the AR9331) doc says:
+	 * reset duration should be greater than 10ms. So, let's use this value
+	 * for now.
+	 */
+	usleep_range(10000, 15000);
+	ret = reset_control_deassert(priv->sw_reset);
+	if (ret)
+		goto error;
+	/* There is no information on how long should we wait after reset.
+	 * AR8136 has an EEPROM and there is an Interrupt for EEPROM load
+	 * status. AR9331 has no EEPROM support.
+	 * For now, do not wait. In case AR8136 will be needed, the after
+	 * reset delay can be added as well.
+	 */
+
+	return 0;
+error:
+	dev_err_ratelimited(priv->dev, "%s: %i\n", __func__, ret);
+	return ret;
+}
+
+static int ar9331_sw_mbus_write(struct mii_bus *mbus, int port, int regnum,
+				u16 data)
+{
+	struct ar9331_sw_priv *priv = mbus->priv;
+	struct regmap *regmap = priv->regmap;
+	u32 val;
+	int ret;
+
+	ret = regmap_write(regmap, AR9331_SW_REG_MDIO_CTRL,
+			   AR9331_SW_MDIO_CTRL_BUSY |
+			   AR9331_SW_MDIO_CTRL_MASTER_EN |
+			   FIELD_PREP(AR9331_SW_MDIO_CTRL_PHY_ADDR_M, port) |
+			   FIELD_PREP(AR9331_SW_MDIO_CTRL_REG_ADDR_M, regnum) |
+			   FIELD_PREP(AR9331_SW_MDIO_CTRL_DATA_M, data));
+	if (ret)
+		goto error;
+
+	ret = regmap_read_poll_timeout(regmap, AR9331_SW_REG_MDIO_CTRL, val,
+				       !(val & AR9331_SW_MDIO_CTRL_BUSY),
+				       AR9331_SW_MDIO_POLL_SLEEP_US,
+				       AR9331_SW_MDIO_POLL_TIMEOUT_US);
+	if (ret)
+		goto error;
+
+	return 0;
+error:
+	dev_err_ratelimited(priv->dev, "PHY write error: %i\n", ret);
+	return ret;
+}
+
+static int ar9331_sw_mbus_read(struct mii_bus *mbus, int port, int regnum)
+{
+	struct ar9331_sw_priv *priv = mbus->priv;
+	struct regmap *regmap = priv->regmap;
+	u32 val;
+	int ret;
+
+	ret = regmap_write(regmap, AR9331_SW_REG_MDIO_CTRL,
+			   AR9331_SW_MDIO_CTRL_BUSY |
+			   AR9331_SW_MDIO_CTRL_MASTER_EN |
+			   AR9331_SW_MDIO_CTRL_CMD_READ |
+			   FIELD_PREP(AR9331_SW_MDIO_CTRL_PHY_ADDR_M, port) |
+			   FIELD_PREP(AR9331_SW_MDIO_CTRL_REG_ADDR_M, regnum));
+	if (ret)
+		goto error;
+
+	ret = regmap_read_poll_timeout(regmap, AR9331_SW_REG_MDIO_CTRL, val,
+				       !(val & AR9331_SW_MDIO_CTRL_BUSY),
+				       AR9331_SW_MDIO_POLL_SLEEP_US,
+				       AR9331_SW_MDIO_POLL_TIMEOUT_US);
+	if (ret)
+		goto error;
+
+	ret = regmap_read(regmap, AR9331_SW_REG_MDIO_CTRL, &val);
+	if (ret)
+		goto error;
+
+	return FIELD_GET(AR9331_SW_MDIO_CTRL_DATA_M, val);
+
+error:
+	dev_err_ratelimited(priv->dev, "PHY read error: %i\n", ret);
+	return ret;
+}
+
+static int ar9331_sw_mbus_init(struct ar9331_sw_priv *priv)
+{
+	struct device *dev = priv->dev;
+	static struct mii_bus *mbus;
+	struct device_node *np, *mnp;
+	int ret;
+
+	np = dev->of_node;
+
+	mbus = devm_mdiobus_alloc(dev);
+	if (!mbus)
+		return -ENOMEM;
+
+	mbus->name = np->full_name;
+	snprintf(mbus->id, MII_BUS_ID_SIZE, "%pOF", np);
+
+	mbus->read = ar9331_sw_mbus_read;
+	mbus->write = ar9331_sw_mbus_write;
+	mbus->priv = priv;
+	mbus->parent = dev;
+
+	mnp = of_get_child_by_name(np, "mdio");
+	if (!mnp)
+		return -ENODEV;
+
+	ret = of_mdiobus_register(mbus, mnp);
+	of_node_put(mnp);
+	if (ret)
+		return ret;
+
+	priv->mbus = mbus;
+
+	return 0;
+}
+
+static int ar9331_sw_setup(struct dsa_switch *ds)
+{
+	struct ar9331_sw_priv *priv = (struct ar9331_sw_priv *)ds->priv;
+	struct regmap *regmap = priv->regmap;
+	int ret;
+
+	ret = ar9331_sw_reset(priv);
+	if (ret)
+		return ret;
+
+	/* Reset will set proper defaults. CPU - Port0 will be enabled and
+	 * configured. All other ports (ports 1 - 5) are disabled
+	 */
+	ret = ar9331_sw_mbus_init(priv);
+	if (ret)
+		return ret;
+
+	/* Do not drop broadcast frames */
+	ret = regmap_write_bits(regmap, AR9331_SW_REG_FLOOD_MASK,
+				AR9331_SW_FLOOD_MASK_BROAD_TO_CPU,
+				AR9331_SW_FLOOD_MASK_BROAD_TO_CPU);
+	if (ret)
+		goto error;
+
+	/* Set max frame size to the maximum supported value */
+	ret = regmap_write_bits(regmap, AR9331_SW_REG_GLOBAL_CTRL,
+				AR9331_SW_GLOBAL_CTRL_MFS_M,
+				AR9331_SW_GLOBAL_CTRL_MFS_M);
+	if (ret)
+		goto error;
+
+	return 0;
+error:
+	dev_err_ratelimited(priv->dev, "%s: %i\n", __func__, ret);
+	return ret;
+}
+
+static void ar9331_sw_port_disable(struct dsa_switch *ds, int port)
+{
+	struct ar9331_sw_priv *priv = (struct ar9331_sw_priv *)ds->priv;
+	struct regmap *regmap = priv->regmap;
+	int ret;
+
+	ret = regmap_write(regmap, AR9331_SW_REG_PORT_STATUS(port), 0);
+	if (ret)
+		dev_err_ratelimited(priv->dev, "%s: %i\n", __func__, ret);
+}
+
+static enum dsa_tag_protocol ar9331_sw_get_tag_protocol(struct dsa_switch *ds,
+							int port)
+{
+	return DSA_TAG_PROTO_AR9331;
+}
+
+static void ar9331_sw_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:
+		if (state->interface != PHY_INTERFACE_MODE_GMII)
+			goto unsupported;
+
+		phylink_set(mask, 1000baseT_Full);
+		phylink_set(mask, 1000baseT_Half);
+		break;
+	case 1:
+	case 2:
+	case 3:
+	case 4:
+	case 5:
+		if (state->interface != PHY_INTERFACE_MODE_INTERNAL)
+			goto unsupported;
+		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);
+	phylink_set(mask, Pause);
+	phylink_set(mask, Asym_Pause);
+
+	phylink_set(mask, 10baseT_Half);
+	phylink_set(mask, 10baseT_Full);
+	phylink_set(mask, 100baseT_Half);
+	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);
+
+	return;
+
+unsupported:
+	bitmap_zero(supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
+	dev_err(ds->dev, "Unsupported interface: %d, port: %d\n",
+		state->interface, port);
+}
+
+static void ar9331_sw_phylink_mac_config(struct dsa_switch *ds, int port,
+					 unsigned int mode,
+					 const struct phylink_link_state *state)
+{
+	struct ar9331_sw_priv *priv = (struct ar9331_sw_priv *)ds->priv;
+	struct regmap *regmap = priv->regmap;
+	int ret;
+	u32 val;
+
+	switch (state->speed) {
+	case SPEED_1000:
+		val = AR9331_SW_PORT_STATUS_SPEED_1000;
+		break;
+	case SPEED_100:
+		val = AR9331_SW_PORT_STATUS_SPEED_100;
+		break;
+	case SPEED_10:
+		val = AR9331_SW_PORT_STATUS_SPEED_10;
+		break;
+	default:
+		return;
+	}
+
+	if (state->duplex)
+		val |= AR9331_SW_PORT_STATUS_DUPLEX_MODE;
+
+	if (state->pause & MLO_PAUSE_TX)
+		val |= AR9331_SW_PORT_STATUS_TX_FLOW_EN;
+
+	if (state->pause & MLO_PAUSE_RX)
+		val |= AR9331_SW_PORT_STATUS_RX_FLOW_EN;
+
+	ret = regmap_update_bits(regmap, AR9331_SW_REG_PORT_STATUS(port),
+				 AR9331_SW_PORT_STATUS_LINK_MASK, val);
+	if (ret)
+		dev_err_ratelimited(priv->dev, "%s: %i\n", __func__, ret);
+}
+
+static void ar9331_sw_phylink_mac_link_down(struct dsa_switch *ds, int port,
+					    unsigned int mode,
+					    phy_interface_t interface)
+{
+	struct ar9331_sw_priv *priv = (struct ar9331_sw_priv *)ds->priv;
+	struct regmap *regmap = priv->regmap;
+	int ret;
+
+	ret = regmap_update_bits(regmap, AR9331_SW_REG_PORT_STATUS(port),
+				 AR9331_SW_PORT_STATUS_MAC_MASK, 0);
+	if (ret)
+		dev_err_ratelimited(priv->dev, "%s: %i\n", __func__, ret);
+}
+
+static void ar9331_sw_phylink_mac_link_up(struct dsa_switch *ds, int port,
+					  unsigned int mode,
+					  phy_interface_t interface,
+					  struct phy_device *phydev)
+{
+	struct ar9331_sw_priv *priv = (struct ar9331_sw_priv *)ds->priv;
+	struct regmap *regmap = priv->regmap;
+	int ret;
+
+	ret = regmap_update_bits(regmap, AR9331_SW_REG_PORT_STATUS(port),
+				 AR9331_SW_PORT_STATUS_MAC_MASK,
+				 AR9331_SW_PORT_STATUS_MAC_MASK);
+	if (ret)
+		dev_err_ratelimited(priv->dev, "%s: %i\n", __func__, ret);
+}
+
+static const struct dsa_switch_ops ar9331_sw_ops = {
+	.get_tag_protocol	= ar9331_sw_get_tag_protocol,
+	.setup			= ar9331_sw_setup,
+	.port_disable		= ar9331_sw_port_disable,
+	.phylink_validate	= ar9331_sw_phylink_validate,
+	.phylink_mac_config	= ar9331_sw_phylink_mac_config,
+	.phylink_mac_link_down	= ar9331_sw_phylink_mac_link_down,
+	.phylink_mac_link_up	= ar9331_sw_phylink_mac_link_up,
+};
+
+static irqreturn_t ar9331_sw_irq(int irq, void *data)
+{
+	struct ar9331_sw_priv *priv = data;
+	struct regmap *regmap = priv->regmap;
+	u32 stat;
+	int ret;
+
+	ret = regmap_read(regmap, AR9331_SW_REG_GINT, &stat);
+	if (ret) {
+		dev_err(priv->dev, "can't read interrupt status\n");
+		return IRQ_NONE;
+	}
+
+	if (!stat)
+		return IRQ_NONE;
+
+	if (stat & AR9331_SW_GINT_PHY_INT) {
+		int child_irq;
+
+		child_irq = irq_find_mapping(priv->irqdomain, 0);
+		handle_nested_irq(child_irq);
+	}
+
+	ret = regmap_write(regmap, AR9331_SW_REG_GINT, stat);
+	if (ret) {
+		dev_err(priv->dev, "can't write interrupt status\n");
+		return IRQ_NONE;
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void ar9331_sw_mask_irq(struct irq_data *d)
+{
+	struct ar9331_sw_priv *priv = irq_data_get_irq_chip_data(d);
+	struct regmap *regmap = priv->regmap;
+	int ret;
+
+	ret = regmap_update_bits(regmap, AR9331_SW_REG_GINT_MASK,
+				 AR9331_SW_GINT_PHY_INT, 0);
+	if (ret)
+		dev_err(priv->dev, "could not mask IRQ\n");
+}
+
+static void ar9331_sw_unmask_irq(struct irq_data *d)
+{
+	struct ar9331_sw_priv *priv = irq_data_get_irq_chip_data(d);
+	struct regmap *regmap = priv->regmap;
+	int ret;
+
+	ret = regmap_update_bits(regmap, AR9331_SW_REG_GINT_MASK,
+				 AR9331_SW_GINT_PHY_INT,
+				 AR9331_SW_GINT_PHY_INT);
+	if (ret)
+		dev_err(priv->dev, "could not unmask IRQ\n");
+}
+
+static struct irq_chip ar9331_sw_irq_chip = {
+	.name = AR9331_SW_NAME,
+	.irq_mask = ar9331_sw_mask_irq,
+	.irq_unmask = ar9331_sw_unmask_irq,
+};
+
+static int ar9331_sw_irq_map(struct irq_domain *domain, unsigned int irq,
+			     irq_hw_number_t hwirq)
+{
+	irq_set_chip_data(irq, domain->host_data);
+	irq_set_chip_and_handler(irq, &ar9331_sw_irq_chip, handle_simple_irq);
+	irq_set_nested_thread(irq, 1);
+	irq_set_noprobe(irq);
+
+	return 0;
+}
+
+static void ar9331_sw_irq_unmap(struct irq_domain *d, unsigned int irq)
+{
+	irq_set_nested_thread(irq, 0);
+	irq_set_chip_and_handler(irq, NULL, NULL);
+	irq_set_chip_data(irq, NULL);
+}
+
+static const struct irq_domain_ops ar9331_sw_irqdomain_ops = {
+	.map = ar9331_sw_irq_map,
+	.unmap = ar9331_sw_irq_unmap,
+	.xlate = irq_domain_xlate_onecell,
+};
+
+static int ar9331_sw_irq_init(struct ar9331_sw_priv *priv)
+{
+	struct device_node *np = priv->dev->of_node;
+	struct device *dev = priv->dev;
+	int ret, irq;
+
+	irq = of_irq_get(np, 0);
+	if (irq <= 0) {
+		dev_err(dev, "failed to get parent IRQ\n");
+		return irq ? irq : -EINVAL;
+	}
+
+	ret = devm_request_threaded_irq(dev, irq, NULL, ar9331_sw_irq,
+					IRQF_ONESHOT, AR9331_SW_NAME, priv);
+	if (ret) {
+		dev_err(dev, "unable to request irq: %d\n", ret);
+		return ret;
+	}
+
+	priv->irqdomain = irq_domain_add_linear(np, 1, &ar9331_sw_irqdomain_ops,
+						priv);
+	if (!priv->irqdomain) {
+		dev_err(dev, "failed to create IRQ domain\n");
+		return -EINVAL;
+	}
+
+	irq_set_parent(irq_create_mapping(priv->irqdomain, 0), irq);
+
+	return 0;
+}
+
+static int __ar9331_mdio_write(struct mii_bus *sbus, u8 mode, u16 reg, u16 val)
+{
+	u8 r, p;
+
+	p = FIELD_PREP(AR9331_SW_MDIO_PHY_MODE_M, mode) |
+		FIELD_GET(AR9331_SW_LOW_ADDR_PHY, reg);
+	r = FIELD_GET(AR9331_SW_LOW_ADDR_REG, reg);
+
+	return mdiobus_write(sbus, p, r, val);
+}
+
+static int __ar9331_mdio_read(struct mii_bus *sbus, u16 reg)
+{
+	u8 r, p;
+
+	p = FIELD_PREP(AR9331_SW_MDIO_PHY_MODE_M, AR9331_SW_MDIO_PHY_MODE_REG) |
+		FIELD_GET(AR9331_SW_LOW_ADDR_PHY, reg);
+	r = FIELD_GET(AR9331_SW_LOW_ADDR_REG, reg);
+
+	return mdiobus_read(sbus, p, r);
+}
+
+static int ar9331_mdio_read(void *ctx, const void *reg_buf, size_t reg_len,
+			    void *val_buf, size_t val_len)
+{
+	struct ar9331_sw_priv *priv = ctx;
+	struct mii_bus *sbus = priv->sbus;
+	u32 reg = *(u32 *)reg_buf;
+	int ret;
+
+	if (reg == AR9331_SW_REG_PAGE) {
+		/* We cannot read the page selector register from hardware and
+		 * we cache its value in regmap. Return all bits set here,
+		 * that regmap will always write the page on first use.
+		 */
+		*(u32 *)val_buf = GENMASK(9, 0);
+		return 0;
+	}
+
+	ret = __ar9331_mdio_read(sbus, reg);
+	if (ret < 0)
+		goto error;
+
+	*(u32 *)val_buf = ret;
+	ret = __ar9331_mdio_read(sbus, reg + 2);
+	if (ret < 0)
+		goto error;
+
+	*(u32 *)val_buf |= ret << 16;
+
+	return 0;
+error:
+	dev_err_ratelimited(&sbus->dev, "Bus error. Failed to read register.\n");
+	return ret;
+}
+
+static int ar9331_mdio_write(void *ctx, u32 reg, u32 val)
+{
+	struct ar9331_sw_priv *priv = (struct ar9331_sw_priv *)ctx;
+	struct mii_bus *sbus = priv->sbus;
+	int ret;
+
+	if (reg == AR9331_SW_REG_PAGE) {
+		ret = __ar9331_mdio_write(sbus, AR9331_SW_MDIO_PHY_MODE_PAGE,
+					  0, val);
+		if (ret < 0)
+			goto error;
+
+		return 0;
+	}
+
+	ret = __ar9331_mdio_write(sbus, AR9331_SW_MDIO_PHY_MODE_REG, reg, val);
+	if (ret < 0)
+		goto error;
+
+	ret = __ar9331_mdio_write(sbus, AR9331_SW_MDIO_PHY_MODE_REG, reg + 2,
+				  val >> 16);
+	if (ret < 0)
+		goto error;
+
+	return 0;
+error:
+	dev_err_ratelimited(&sbus->dev, "Bus error. Failed to write register.\n");
+	return ret;
+}
+
+static int ar9331_sw_bus_write(void *context, const void *data, size_t count)
+{
+	u32 reg = *(u32 *)data;
+	u32 val = *((u32 *)data + 1);
+
+	return ar9331_mdio_write(context, reg, val);
+}
+
+static const struct regmap_range ar9331_valid_regs[] = {
+	regmap_reg_range(0x0, 0x0),
+	regmap_reg_range(0x10, 0x14),
+	regmap_reg_range(0x20, 0x24),
+	regmap_reg_range(0x2c, 0x30),
+	regmap_reg_range(0x40, 0x44),
+	regmap_reg_range(0x50, 0x78),
+	regmap_reg_range(0x80, 0x98),
+
+	regmap_reg_range(0x100, 0x120),
+	regmap_reg_range(0x200, 0x220),
+	regmap_reg_range(0x300, 0x320),
+	regmap_reg_range(0x400, 0x420),
+	regmap_reg_range(0x500, 0x520),
+	regmap_reg_range(0x600, 0x620),
+
+	regmap_reg_range(0x20000, 0x200a4),
+	regmap_reg_range(0x20100, 0x201a4),
+	regmap_reg_range(0x20200, 0x202a4),
+	regmap_reg_range(0x20300, 0x203a4),
+	regmap_reg_range(0x20400, 0x204a4),
+	regmap_reg_range(0x20500, 0x205a4),
+
+	/* dummy page selector reg */
+	regmap_reg_range(AR9331_SW_REG_PAGE, AR9331_SW_REG_PAGE),
+};
+
+static const struct regmap_range ar9331_nonvolatile_regs[] = {
+	regmap_reg_range(AR9331_SW_REG_PAGE, AR9331_SW_REG_PAGE),
+};
+
+static const struct regmap_range_cfg ar9331_regmap_range[] = {
+	{
+		.selector_reg = AR9331_SW_REG_PAGE,
+		.selector_mask = GENMASK(9, 0),
+		.selector_shift = 0,
+
+		.window_start = 0,
+		.window_len = 512,
+
+		.range_min = 0,
+		.range_max = AR9331_SW_REG_PAGE - 4,
+	},
+};
+
+static const struct regmap_access_table ar9331_register_set = {
+	.yes_ranges = ar9331_valid_regs,
+	.n_yes_ranges = ARRAY_SIZE(ar9331_valid_regs),
+};
+
+static const struct regmap_access_table ar9331_volatile_set = {
+	.no_ranges = ar9331_nonvolatile_regs,
+	.n_no_ranges = ARRAY_SIZE(ar9331_nonvolatile_regs),
+};
+
+static const struct regmap_config ar9331_mdio_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = AR9331_SW_REG_PAGE,
+
+	.ranges = ar9331_regmap_range,
+	.num_ranges = ARRAY_SIZE(ar9331_regmap_range),
+
+	.volatile_table = &ar9331_volatile_set,
+	.wr_table = &ar9331_register_set,
+	.rd_table = &ar9331_register_set,
+
+	.cache_type = REGCACHE_RBTREE,
+};
+
+static struct regmap_bus ar9331_sw_bus = {
+	.reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
+	.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
+	.read = ar9331_mdio_read,
+	.write = ar9331_sw_bus_write,
+	.max_raw_read = 4,
+	.max_raw_write = 4,
+};
+
+static int ar9331_sw_probe(struct mdio_device *mdiodev)
+{
+	struct ar9331_sw_priv *priv;
+	struct dsa_switch *ds;
+	int ret;
+
+	priv = devm_kzalloc(&mdiodev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->regmap = devm_regmap_init(&mdiodev->dev, &ar9331_sw_bus, priv,
+					&ar9331_mdio_regmap_config);
+	if (IS_ERR(priv->regmap)) {
+		ret = PTR_ERR(priv->regmap);
+		dev_err(&mdiodev->dev, "regmap init failed: %d\n", ret);
+		return ret;
+	}
+
+	priv->sw_reset = devm_reset_control_get(&mdiodev->dev, "switch");
+	if (IS_ERR(priv->sw_reset)) {
+		dev_err(&mdiodev->dev, "missing switch reset\n");
+		return PTR_ERR(priv->sw_reset);
+	}
+
+	priv->sbus = mdiodev->bus;
+	priv->dev = &mdiodev->dev;
+
+	ret = ar9331_sw_irq_init(priv);
+	if (ret)
+		return ret;
+
+	ds = &priv->ds;
+	ds->dev = &mdiodev->dev;
+	ds->num_ports = AR9331_SW_PORTS;
+	ds->priv = priv;
+	priv->ops = ar9331_sw_ops;
+	ds->ops = &priv->ops;
+	dev_set_drvdata(&mdiodev->dev, priv);
+
+	ret = dsa_register_switch(ds);
+	if (ret)
+		goto err_remove_irq;
+
+	return 0;
+
+err_remove_irq:
+	irq_domain_remove(priv->irqdomain);
+
+	return ret;
+}
+
+static void ar9331_sw_remove(struct mdio_device *mdiodev)
+{
+	struct ar9331_sw_priv *priv = dev_get_drvdata(&mdiodev->dev);
+
+	irq_domain_remove(priv->irqdomain);
+	mdiobus_unregister(priv->mbus);
+	dsa_unregister_switch(&priv->ds);
+
+	reset_control_assert(priv->sw_reset);
+}
+
+static const struct of_device_id ar9331_sw_of_match[] = {
+	{ .compatible = "qca,ar9331-switch" },
+	{ },
+};
+
+static struct mdio_driver ar9331_sw_mdio_driver = {
+	.probe = ar9331_sw_probe,
+	.remove = ar9331_sw_remove,
+	.mdiodrv.driver = {
+		.name = AR9331_SW_NAME,
+		.of_match_table = ar9331_sw_of_match,
+	},
+};
+
+mdio_module_driver(ar9331_sw_mdio_driver);
+
+MODULE_AUTHOR("Oleksij Rempel <kernel@pengutronix.de>");
+MODULE_DESCRIPTION("Driver for Atheros AR9331 switch");
+MODULE_LICENSE("GPL v2");
diff --git a/include/net/dsa.h b/include/net/dsa.h
index 6767dc3f66c0..da5578db228e 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -43,6 +43,7 @@ struct phylink_link_state;
 #define DSA_TAG_PROTO_SJA1105_VALUE		13
 #define DSA_TAG_PROTO_KSZ8795_VALUE		14
 #define DSA_TAG_PROTO_OCELOT_VALUE		15
+#define DSA_TAG_PROTO_AR9331_VALUE		16
 
 enum dsa_tag_protocol {
 	DSA_TAG_PROTO_NONE		= DSA_TAG_PROTO_NONE_VALUE,
@@ -61,6 +62,7 @@ enum dsa_tag_protocol {
 	DSA_TAG_PROTO_SJA1105		= DSA_TAG_PROTO_SJA1105_VALUE,
 	DSA_TAG_PROTO_KSZ8795		= DSA_TAG_PROTO_KSZ8795_VALUE,
 	DSA_TAG_PROTO_OCELOT		= DSA_TAG_PROTO_OCELOT_VALUE,
+	DSA_TAG_PROTO_AR9331		= DSA_TAG_PROTO_AR9331_VALUE,
 };
 
 struct packet_type;
diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig
index 1e6c3cac11e6..92663dcb3aa2 100644
--- a/net/dsa/Kconfig
+++ b/net/dsa/Kconfig
@@ -29,6 +29,12 @@ config NET_DSA_TAG_8021Q
 
 	  Drivers which use these helpers should select this as dependency.
 
+config NET_DSA_TAG_AR9331
+	tristate "Tag driver for Atheros AR9331 SoC with built-in switch"
+	help
+	  Say Y or M if you want to enable support for tagging frames for
+	  the Atheros AR9331 SoC with built-in switch.
+
 config NET_DSA_TAG_BRCM_COMMON
 	tristate
 	default n
diff --git a/net/dsa/Makefile b/net/dsa/Makefile
index 9a482c38bdb1..108486cfdeef 100644
--- a/net/dsa/Makefile
+++ b/net/dsa/Makefile
@@ -5,6 +5,7 @@ dsa_core-y += dsa.o dsa2.o master.o port.o slave.o switch.o
 
 # tagging formats
 obj-$(CONFIG_NET_DSA_TAG_8021Q) += tag_8021q.o
+obj-$(CONFIG_NET_DSA_TAG_AR9331) += tag_ar9331.o
 obj-$(CONFIG_NET_DSA_TAG_BRCM_COMMON) += tag_brcm.o
 obj-$(CONFIG_NET_DSA_TAG_DSA) += tag_dsa.o
 obj-$(CONFIG_NET_DSA_TAG_EDSA) += tag_edsa.o
diff --git a/net/dsa/tag_ar9331.c b/net/dsa/tag_ar9331.c
new file mode 100644
index 000000000000..466ffa92a474
--- /dev/null
+++ b/net/dsa/tag_ar9331.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019 Pengutronix, Oleksij Rempel <kernel@pengutronix.de>
+ */
+
+
+#include <linux/bitfield.h>
+#include <linux/etherdevice.h>
+
+#include "dsa_priv.h"
+
+#define AR9331_HDR_LEN			2
+#define AR9331_HDR_VERSION		1
+
+#define AR9331_HDR_VERSION_MASK		GENMASK(15, 14)
+#define AR9331_HDR_PRIORITY_MASK	GENMASK(13, 12)
+#define AR9331_HDR_TYPE_MASK		GENMASK(10, 8)
+#define AR9331_HDR_BROADCAST		BIT(7)
+#define AR9331_HDR_FROM_CPU		BIT(6)
+/* AR9331_HDR_RESERVED - not used or may be version field.
+ * According to the AR8216 doc it should 0b10. On AR9331 it is 0b11 on RX path
+ * and should be set to 0b11 to make it work.
+ */
+#define AR9331_HDR_RESERVED_MASK	GENMASK(5, 4)
+#define AR9331_HDR_PORT_NUM_MASK	GENMASK(3, 0)
+
+static struct sk_buff *ar9331_tag_xmit(struct sk_buff *skb,
+				       struct net_device *dev)
+{
+	struct dsa_port *dp = dsa_slave_to_port(dev);
+	__le16 *phdr;
+	u16 hdr;
+
+	if (skb_cow_head(skb, 0) < 0)
+		return NULL;
+
+	phdr = skb_push(skb, AR9331_HDR_LEN);
+
+	hdr = FIELD_PREP(AR9331_HDR_VERSION_MASK, AR9331_HDR_VERSION);
+	hdr |= AR9331_HDR_FROM_CPU | dp->index;
+	/* 0b10 for AR8216 and 0b11 for AR9331 */
+	hdr |= AR9331_HDR_RESERVED_MASK;
+
+	phdr[0] = cpu_to_le16(hdr);
+
+	return skb;
+}
+
+static struct sk_buff *ar9331_tag_rcv(struct sk_buff *skb,
+				      struct net_device *ndev,
+				      struct packet_type *pt)
+{
+	u8 ver, port;
+	u16 hdr;
+
+	if (unlikely(!pskb_may_pull(skb, AR9331_HDR_LEN)))
+		return NULL;
+
+	hdr = le16_to_cpu(*(__le16 *)skb_mac_header(skb));
+
+	ver = FIELD_GET(AR9331_HDR_VERSION_MASK, hdr);
+	if (unlikely(ver != AR9331_HDR_VERSION)) {
+		netdev_warn_once(ndev, "%s:%i wrong header version 0x%2x\n",
+				 __func__, __LINE__, hdr);
+		return NULL;
+	}
+
+	if (unlikely(hdr & AR9331_HDR_FROM_CPU)) {
+		netdev_warn_once(ndev, "%s:%i packet should not be from cpu 0x%2x\n",
+				 __func__, __LINE__, hdr);
+		return NULL;
+	}
+
+	skb_pull_rcsum(skb, AR9331_HDR_LEN);
+
+	/* Get source port information */
+	port = FIELD_GET(AR9331_HDR_PORT_NUM_MASK, hdr);
+
+	skb->dev = dsa_master_find_slave(ndev, 0, port);
+	if (!skb->dev)
+		return NULL;
+
+	return skb;
+}
+
+static const struct dsa_device_ops ar9331_netdev_ops = {
+	.name	= "ar9331",
+	.proto	= DSA_TAG_PROTO_AR9331,
+	.xmit	= ar9331_tag_xmit,
+	.rcv	= ar9331_tag_rcv,
+	.overhead = AR9331_HDR_LEN,
+};
+
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_AR9331);
+module_dsa_tag_driver(ar9331_netdev_ops);