net: dsa: microchip: add DSA support for microchip LAN937x

Basic DSA driver support for lan937x and the device will be
configured through SPI interface.
It adds the lan937x_dev_ops in ksz_common.c file and tries to reuse the
functionality of ksz9477 series switch.

drivers/net/dsa/microchip/ path is already part of MAINTAINERS &
the new files come under this path. Hence no update needed to the
MAINTAINERS
Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/microchip/Kconfig

 # SPDX-License-Identifier: GPL-2.0-only
 menuconfig NET_DSA_MICROCHIP_KSZ_COMMON
-	tristate "Microchip KSZ8795/KSZ9477 series switch support"
+	tristate "Microchip KSZ8795/KSZ9477/LAN937x series switch support"
 	depends on NET_DSA
 	select NET_DSA_TAG_KSZ
 	help

drivers/net/dsa/microchip/Makefile

@@ -3,6 +3,7 @@ obj-$(CONFIG_NET_DSA_MICROCHIP_KSZ_COMMON)	+= ksz_switch.o
 ksz_switch-objs := ksz_common.o
 ksz_switch-objs += ksz9477.o
 ksz_switch-objs += ksz8795.o
+ksz_switch-objs += lan937x_main.o
 obj-$(CONFIG_NET_DSA_MICROCHIP_KSZ9477_I2C)	+= ksz9477_i2c.o
 obj-$(CONFIG_NET_DSA_MICROCHIP_KSZ_SPI)		+= ksz_spi.o
 obj-$(CONFIG_NET_DSA_MICROCHIP_KSZ8863_SMI)	+= ksz8863_smi.o

drivers/net/dsa/microchip/ksz_common.c

@@ -23,6 +23,7 @@
 #include "ksz_common.h"
 #include "ksz8.h"
 #include "ksz9477.h"
+#include "lan937x.h"
 
 #define MIB_COUNTER_NUM 0x20
 
@@ -201,6 +202,34 @@ static const struct ksz_dev_ops ksz9477_dev_ops = {
 	.exit = ksz9477_switch_exit,
 };
 
+static const struct ksz_dev_ops lan937x_dev_ops = {
+	.setup = lan937x_setup,
+	.get_port_addr = ksz9477_get_port_addr,
+	.cfg_port_member = ksz9477_cfg_port_member,
+	.port_setup = lan937x_port_setup,
+	.r_mib_cnt = ksz9477_r_mib_cnt,
+	.r_mib_pkt = ksz9477_r_mib_pkt,
+	.r_mib_stat64 = ksz_r_mib_stats64,
+	.freeze_mib = ksz9477_freeze_mib,
+	.port_init_cnt = ksz9477_port_init_cnt,
+	.vlan_filtering = ksz9477_port_vlan_filtering,
+	.vlan_add = ksz9477_port_vlan_add,
+	.vlan_del = ksz9477_port_vlan_del,
+	.mirror_add = ksz9477_port_mirror_add,
+	.mirror_del = ksz9477_port_mirror_del,
+	.fdb_dump = ksz9477_fdb_dump,
+	.fdb_add = ksz9477_fdb_add,
+	.fdb_del = ksz9477_fdb_del,
+	.mdb_add = ksz9477_mdb_add,
+	.mdb_del = ksz9477_mdb_del,
+	.max_mtu = ksz9477_max_mtu,
+	.config_cpu_port = lan937x_config_cpu_port,
+	.enable_stp_addr = ksz9477_enable_stp_addr,
+	.reset = lan937x_reset_switch,
+	.init = lan937x_switch_init,
+	.exit = lan937x_switch_exit,
+};
+
 static const u16 ksz8795_regs[] = {
 	[REG_IND_CTRL_0]		= 0x6E,
 	[REG_IND_DATA_8]		= 0x70,
@@ -542,6 +571,7 @@ const struct ksz_chip_data ksz_switch_chips[] = {
 		.num_statics = 256,
 		.cpu_ports = 0x10,	/* can be configured as cpu port */
 		.port_cnt = 5,		/* total physical port count */
+		.ops = &lan937x_dev_ops,
 		.mib_names = ksz9477_mib_names,
 		.mib_cnt = ARRAY_SIZE(ksz9477_mib_names),
 		.reg_mib_cnt = MIB_COUNTER_NUM,
@@ -562,6 +592,7 @@ const struct ksz_chip_data ksz_switch_chips[] = {
 		.num_statics = 256,
 		.cpu_ports = 0x30,	/* can be configured as cpu port */
 		.port_cnt = 6,		/* total physical port count */
+		.ops = &lan937x_dev_ops,
 		.mib_names = ksz9477_mib_names,
 		.mib_cnt = ARRAY_SIZE(ksz9477_mib_names),
 		.reg_mib_cnt = MIB_COUNTER_NUM,
@@ -582,6 +613,7 @@ const struct ksz_chip_data ksz_switch_chips[] = {
 		.num_statics = 256,
 		.cpu_ports = 0x30,	/* can be configured as cpu port */
 		.port_cnt = 8,		/* total physical port count */
+		.ops = &lan937x_dev_ops,
 		.mib_names = ksz9477_mib_names,
 		.mib_cnt = ARRAY_SIZE(ksz9477_mib_names),
 		.reg_mib_cnt = MIB_COUNTER_NUM,
@@ -606,6 +638,7 @@ const struct ksz_chip_data ksz_switch_chips[] = {
 		.num_statics = 256,
 		.cpu_ports = 0x38,	/* can be configured as cpu port */
 		.port_cnt = 5,		/* total physical port count */
+		.ops = &lan937x_dev_ops,
 		.mib_names = ksz9477_mib_names,
 		.mib_cnt = ARRAY_SIZE(ksz9477_mib_names),
 		.reg_mib_cnt = MIB_COUNTER_NUM,
@@ -630,6 +663,7 @@ const struct ksz_chip_data ksz_switch_chips[] = {
 		.num_statics = 256,
 		.cpu_ports = 0x30,	/* can be configured as cpu port */
 		.port_cnt = 8,		/* total physical port count */
+		.ops = &lan937x_dev_ops,
 		.mib_names = ksz9477_mib_names,
 		.mib_cnt = ARRAY_SIZE(ksz9477_mib_names),
 		.reg_mib_cnt = MIB_COUNTER_NUM,

drivers/net/dsa/microchip/lan937x.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/* Microchip lan937x dev ops headers
+ * Copyright (C) 2019-2022 Microchip Technology Inc.
+ */
+
+#ifndef __LAN937X_CFG_H
+#define __LAN937X_CFG_H
+
+int lan937x_reset_switch(struct ksz_device *dev);
+int lan937x_setup(struct dsa_switch *ds);
+void lan937x_port_setup(struct ksz_device *dev, int port, bool cpu_port);
+void lan937x_config_cpu_port(struct dsa_switch *ds);
+int lan937x_switch_init(struct ksz_device *dev);
+void lan937x_switch_exit(struct ksz_device *dev);
+#endif

drivers/net/dsa/microchip/lan937x_main.c

+// SPDX-License-Identifier: GPL-2.0
+/* Microchip LAN937X switch driver main logic
+ * Copyright (C) 2019-2022 Microchip Technology Inc.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/iopoll.h>
+#include <linux/phy.h>
+#include <linux/of_net.h>
+#include <linux/if_bridge.h>
+#include <linux/math.h>
+#include <net/dsa.h>
+#include <net/switchdev.h>
+
+#include "lan937x_reg.h"
+#include "ksz_common.h"
+#include "lan937x.h"
+
+static int lan937x_cfg(struct ksz_device *dev, u32 addr, u8 bits, bool set)
+{
+	return regmap_update_bits(dev->regmap[0], addr, bits, set ? bits : 0);
+}
+
+static int lan937x_port_cfg(struct ksz_device *dev, int port, int offset,
+			    u8 bits, bool set)
+{
+	return regmap_update_bits(dev->regmap[0], PORT_CTRL_ADDR(port, offset),
+				  bits, set ? bits : 0);
+}
+
+int lan937x_reset_switch(struct ksz_device *dev)
+{
+	u32 data32;
+	int ret;
+
+	/* reset switch */
+	ret = lan937x_cfg(dev, REG_SW_OPERATION, SW_RESET, true);
+	if (ret < 0)
+		return ret;
+
+	/* Enable Auto Aging */
+	ret = lan937x_cfg(dev, REG_SW_LUE_CTRL_1, SW_LINK_AUTO_AGING, true);
+	if (ret < 0)
+		return ret;
+
+	/* disable interrupts */
+	ret = ksz_write32(dev, REG_SW_INT_MASK__4, SWITCH_INT_MASK);
+	if (ret < 0)
+		return ret;
+
+	ret = ksz_write32(dev, REG_SW_PORT_INT_MASK__4, 0xFF);
+	if (ret < 0)
+		return ret;
+
+	return ksz_read32(dev, REG_SW_PORT_INT_STATUS__4, &data32);
+}
+
+void lan937x_port_setup(struct ksz_device *dev, int port, bool cpu_port)
+{
+	struct dsa_switch *ds = dev->ds;
+	u8 member;
+
+	/* enable tag tail for host port */
+	if (cpu_port)
+		lan937x_port_cfg(dev, port, REG_PORT_CTRL_0,
+				 PORT_TAIL_TAG_ENABLE, true);
+
+	/* disable frame check length field */
+	lan937x_port_cfg(dev, port, REG_PORT_MAC_CTRL_0, PORT_CHECK_LENGTH,
+			 false);
+
+	/* set back pressure for half duplex */
+	lan937x_port_cfg(dev, port, REG_PORT_MAC_CTRL_1, PORT_BACK_PRESSURE,
+			 true);
+
+	/* enable 802.1p priority */
+	lan937x_port_cfg(dev, port, P_PRIO_CTRL, PORT_802_1P_PRIO_ENABLE, true);
+
+	if (!dev->info->internal_phy[port])
+		lan937x_port_cfg(dev, port, REG_PORT_XMII_CTRL_0,
+				 PORT_MII_TX_FLOW_CTRL | PORT_MII_RX_FLOW_CTRL,
+				 true);
+
+	if (cpu_port)
+		member = dsa_user_ports(ds);
+	else
+		member = BIT(dsa_upstream_port(ds, port));
+
+	dev->dev_ops->cfg_port_member(dev, port, member);
+}
+
+void lan937x_config_cpu_port(struct dsa_switch *ds)
+{
+	struct ksz_device *dev = ds->priv;
+	struct dsa_port *dp;
+
+	dsa_switch_for_each_cpu_port(dp, ds) {
+		if (dev->info->cpu_ports & (1 << dp->index)) {
+			dev->cpu_port = dp->index;
+
+			/* enable cpu port */
+			lan937x_port_setup(dev, dp->index, true);
+		}
+	}
+
+	dsa_switch_for_each_user_port(dp, ds) {
+		ksz_port_stp_state_set(ds, dp->index, BR_STATE_DISABLED);
+	}
+}
+
+int lan937x_setup(struct dsa_switch *ds)
+{
+	struct ksz_device *dev = ds->priv;
+
+	/* The VLAN aware is a global setting. Mixed vlan
+	 * filterings are not supported.
+	 */
+	ds->vlan_filtering_is_global = true;
+
+	/* Enable aggressive back off for half duplex & UNH mode */
+	lan937x_cfg(dev, REG_SW_MAC_CTRL_0,
+		    (SW_PAUSE_UNH_MODE | SW_NEW_BACKOFF | SW_AGGR_BACKOFF),
+		    true);
+
+	/* If NO_EXC_COLLISION_DROP bit is set, the switch will not drop
+	 * packets when 16 or more collisions occur
+	 */
+	lan937x_cfg(dev, REG_SW_MAC_CTRL_1, NO_EXC_COLLISION_DROP, true);
+
+	/* enable global MIB counter freeze function */
+	lan937x_cfg(dev, REG_SW_MAC_CTRL_6, SW_MIB_COUNTER_FREEZE, true);
+
+	/* disable CLK125 & CLK25, 1: disable, 0: enable */
+	lan937x_cfg(dev, REG_SW_GLOBAL_OUTPUT_CTRL__1,
+		    (SW_CLK125_ENB | SW_CLK25_ENB), true);
+
+	return 0;
+}
+
+int lan937x_switch_init(struct ksz_device *dev)
+{
+	dev->port_mask = (1 << dev->info->port_cnt) - 1;
+
+	return 0;
+}
+
+void lan937x_switch_exit(struct ksz_device *dev)
+{
+	lan937x_reset_switch(dev);
+}
+
+MODULE_AUTHOR("Arun Ramadoss <arun.ramadoss@microchip.com>");
+MODULE_DESCRIPTION("Microchip LAN937x Series Switch DSA Driver");
+MODULE_LICENSE("GPL");

drivers/net/dsa/microchip/lan937x_reg.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/* Microchip LAN937X switch register definitions
+ * Copyright (C) 2019-2021 Microchip Technology Inc.
+ */
+#ifndef __LAN937X_REG_H
+#define __LAN937X_REG_H
+
+#define PORT_CTRL_ADDR(port, addr)	((addr) | (((port) + 1)  << 12))
+
+/* 0 - Operation */
+#define REG_SW_INT_STATUS__4		0x0010
+#define REG_SW_INT_MASK__4		0x0014
+
+#define LUE_INT				BIT(31)
+#define TRIG_TS_INT			BIT(30)
+#define APB_TIMEOUT_INT			BIT(29)
+#define OVER_TEMP_INT			BIT(28)
+#define HSR_INT				BIT(27)
+#define PIO_INT				BIT(26)
+#define POR_READY_INT			BIT(25)
+
+#define SWITCH_INT_MASK			\
+	(LUE_INT | TRIG_TS_INT | APB_TIMEOUT_INT | OVER_TEMP_INT | HSR_INT | \
+	 PIO_INT | POR_READY_INT)
+
+#define REG_SW_PORT_INT_STATUS__4	0x0018
+#define REG_SW_PORT_INT_MASK__4		0x001C
+
+/* 1 - Global */
+#define REG_SW_GLOBAL_OUTPUT_CTRL__1	0x0103
+#define SW_CLK125_ENB			BIT(1)
+#define SW_CLK25_ENB			BIT(0)
+
+/* 3 - Operation Control */
+#define REG_SW_OPERATION		0x0300
+
+#define SW_DOUBLE_TAG			BIT(7)
+#define SW_OVER_TEMP_ENABLE		BIT(2)
+#define SW_RESET			BIT(1)
+
+#define REG_SW_LUE_CTRL_0		0x0310
+
+#define SW_VLAN_ENABLE			BIT(7)
+#define SW_DROP_INVALID_VID		BIT(6)
+#define SW_AGE_CNT_M			0x7
+#define SW_AGE_CNT_S			3
+#define SW_RESV_MCAST_ENABLE		BIT(2)
+
+#define REG_SW_LUE_CTRL_1		0x0311
+
+#define UNICAST_LEARN_DISABLE		BIT(7)
+#define SW_FLUSH_STP_TABLE		BIT(5)
+#define SW_FLUSH_MSTP_TABLE		BIT(4)
+#define SW_SRC_ADDR_FILTER		BIT(3)
+#define SW_AGING_ENABLE			BIT(2)
+#define SW_FAST_AGING			BIT(1)
+#define SW_LINK_AUTO_AGING		BIT(0)
+
+#define REG_SW_MAC_CTRL_0		0x0330
+#define SW_NEW_BACKOFF			BIT(7)
+#define SW_PAUSE_UNH_MODE		BIT(1)
+#define SW_AGGR_BACKOFF			BIT(0)
+
+#define REG_SW_MAC_CTRL_1		0x0331
+#define SW_SHORT_IFG			BIT(7)
+#define MULTICAST_STORM_DISABLE		BIT(6)
+#define SW_BACK_PRESSURE		BIT(5)
+#define FAIR_FLOW_CTRL			BIT(4)
+#define NO_EXC_COLLISION_DROP		BIT(3)
+#define SW_LEGAL_PACKET_DISABLE		BIT(1)
+#define SW_PASS_SHORT_FRAME		BIT(0)
+
+#define REG_SW_MAC_CTRL_6		0x0336
+#define SW_MIB_COUNTER_FLUSH		BIT(7)
+#define SW_MIB_COUNTER_FREEZE		BIT(6)
+
+/* 4 - LUE */
+#define REG_SW_ALU_STAT_CTRL__4		0x041C
+
+#define REG_SW_ALU_VAL_B		0x0424
+#define ALU_V_OVERRIDE			BIT(31)
+#define ALU_V_USE_FID			BIT(30)
+#define ALU_V_PORT_MAP			0xFF
+
+/* Port Registers */
+
+/* 0 - Operation */
+#define REG_PORT_CTRL_0			0x0020
+
+#define PORT_MAC_LOOPBACK		BIT(7)
+#define PORT_MAC_REMOTE_LOOPBACK	BIT(6)
+#define PORT_K2L_INSERT_ENABLE		BIT(5)
+#define PORT_K2L_DEBUG_ENABLE		BIT(4)
+#define PORT_TAIL_TAG_ENABLE		BIT(2)
+#define PORT_QUEUE_SPLIT_ENABLE		0x3
+
+/* 3 - xMII */
+#define REG_PORT_XMII_CTRL_0		0x0300
+#define PORT_SGMII_SEL			BIT(7)
+#define PORT_MII_FULL_DUPLEX		BIT(6)
+#define PORT_MII_TX_FLOW_CTRL		BIT(5)
+#define PORT_MII_100MBIT		BIT(4)
+#define PORT_MII_RX_FLOW_CTRL		BIT(3)
+#define PORT_GRXC_ENABLE		BIT(0)
+
+/* 4 - MAC */
+#define REG_PORT_MAC_CTRL_0		0x0400
+#define PORT_CHECK_LENGTH		BIT(2)
+#define PORT_BROADCAST_STORM		BIT(1)
+#define PORT_JUMBO_PACKET		BIT(0)
+
+#define REG_PORT_MAC_CTRL_1		0x0401
+#define PORT_BACK_PRESSURE		BIT(3)
+#define PORT_PASS_ALL			BIT(0)
+
+/* 8 - Classification and Policing */
+#define REG_PORT_MRI_PRIO_CTRL		0x0801
+#define PORT_HIGHEST_PRIO		BIT(7)
+#define PORT_OR_PRIO			BIT(6)
+#define PORT_MAC_PRIO_ENABLE		BIT(4)
+#define PORT_VLAN_PRIO_ENABLE		BIT(3)
+#define PORT_802_1P_PRIO_ENABLE		BIT(2)
+#define PORT_DIFFSERV_PRIO_ENABLE	BIT(1)
+#define PORT_ACL_PRIO_ENABLE		BIT(0)
+
+#define P_PRIO_CTRL			REG_PORT_MRI_PRIO_CTRL
+
+#endif