xref: /linux/drivers/net/dsa/yt921x.c (revision 24f171c7e145f43b9f187578e89b0982ce87e54c)

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Driver for Motorcomm YT921x Switch
 *
 * Should work on YT9213/YT9214/YT9215/YT9218, but only tested on YT9215+SGMII,
 * be sure to do your own checks before porting to another chip.
 *
 * Copyright (c) 2025 David Yang
 */

#include <linux/etherdevice.h>
#include <linux/if_bridge.h>
#include <linux/if_hsr.h>
#include <linux/if_vlan.h>
#include <linux/iopoll.h>
#include <linux/mdio.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_mdio.h>
#include <linux/of_net.h>

#include <net/dsa.h>

#include "yt921x.h"

struct yt921x_mib_desc {
	unsigned int size;
	unsigned int offset;
	const char *name;
};

#define MIB_DESC(_size, _offset, _name) \
	{_size, _offset, _name}

/* Must agree with yt921x_mib
 *
 * Unstructured fields (name != NULL) will appear in get_ethtool_stats(),
 * structured go to their *_stats() methods, but we need their sizes and offsets
 * to perform 32bit MIB overflow wraparound.
 */
static const struct yt921x_mib_desc yt921x_mib_descs[] = {
	MIB_DESC(1, YT921X_MIB_DATA_RX_BROADCAST, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_RX_PAUSE, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_RX_MULTICAST, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_RX_CRC_ERR, NULL),

	MIB_DESC(1, YT921X_MIB_DATA_RX_ALIGN_ERR, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_RX_UNDERSIZE_ERR, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_RX_FRAG_ERR, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_64, NULL),

	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_65_TO_127, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_128_TO_255, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_256_TO_511, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_512_TO_1023, NULL),

	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_1024_TO_1518, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_1519_TO_MAX, NULL),
	MIB_DESC(2, YT921X_MIB_DATA_RX_GOOD_BYTES, NULL),

	MIB_DESC(2, YT921X_MIB_DATA_RX_BAD_BYTES, "RxBadBytes"),
	MIB_DESC(1, YT921X_MIB_DATA_RX_OVERSIZE_ERR, NULL),

	MIB_DESC(1, YT921X_MIB_DATA_RX_DROPPED, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_TX_BROADCAST, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_TX_PAUSE, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_TX_MULTICAST, NULL),

	MIB_DESC(1, YT921X_MIB_DATA_TX_UNDERSIZE_ERR, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_64, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_65_TO_127, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_128_TO_255, NULL),

	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_256_TO_511, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_512_TO_1023, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_1024_TO_1518, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_1519_TO_MAX, NULL),

	MIB_DESC(2, YT921X_MIB_DATA_TX_GOOD_BYTES, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_TX_COLLISION, NULL),

	MIB_DESC(1, YT921X_MIB_DATA_TX_EXCESSIVE_COLLISION, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_TX_MULTIPLE_COLLISION, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_TX_SINGLE_COLLISION, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT, NULL),

	MIB_DESC(1, YT921X_MIB_DATA_TX_DEFERRED, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_TX_LATE_COLLISION, NULL),
	MIB_DESC(1, YT921X_MIB_DATA_RX_OAM, "RxOAM"),
	MIB_DESC(1, YT921X_MIB_DATA_TX_OAM, "TxOAM"),
};

struct yt921x_info {
	const char *name;
	u16 major;
	/* Unknown, seems to be plain enumeration */
	u8 mode;
	u8 extmode;
	/* Ports with integral GbE PHYs, not including MCU Port 10 */
	u16 internal_mask;
	/* TODO: see comments in yt921x_dsa_phylink_get_caps() */
	u16 external_mask;
};

#define YT921X_PORT_MASK_INTn(port)	BIT(port)
#define YT921X_PORT_MASK_INT0_n(n)	GENMASK((n) - 1, 0)
#define YT921X_PORT_MASK_EXT0		BIT(8)
#define YT921X_PORT_MASK_EXT1		BIT(9)

static const struct yt921x_info yt921x_infos[] = {
	{
		"YT9215SC", YT9215_MAJOR, 1, 0,
		YT921X_PORT_MASK_INT0_n(5),
		YT921X_PORT_MASK_EXT0 | YT921X_PORT_MASK_EXT1,
	},
	{
		"YT9215S", YT9215_MAJOR, 2, 0,
		YT921X_PORT_MASK_INT0_n(5),
		YT921X_PORT_MASK_EXT0 | YT921X_PORT_MASK_EXT1,
	},
	{
		"YT9215RB", YT9215_MAJOR, 3, 0,
		YT921X_PORT_MASK_INT0_n(5),
		YT921X_PORT_MASK_EXT0 | YT921X_PORT_MASK_EXT1,
	},
	{
		"YT9214NB", YT9215_MAJOR, 3, 2,
		YT921X_PORT_MASK_INTn(1) | YT921X_PORT_MASK_INTn(3),
		YT921X_PORT_MASK_EXT0 | YT921X_PORT_MASK_EXT1,
	},
	{
		"YT9213NB", YT9215_MAJOR, 3, 3,
		YT921X_PORT_MASK_INTn(1) | YT921X_PORT_MASK_INTn(3),
		YT921X_PORT_MASK_EXT1,
	},
	{
		"YT9218N", YT9218_MAJOR, 0, 0,
		YT921X_PORT_MASK_INT0_n(8),
		0,
	},
	{
		"YT9218MB", YT9218_MAJOR, 1, 0,
		YT921X_PORT_MASK_INT0_n(8),
		YT921X_PORT_MASK_EXT0 | YT921X_PORT_MASK_EXT1,
	},
	{}
};

#define YT921X_NAME	"yt921x"

#define YT921X_VID_UNWARE	4095

#define YT921X_POLL_SLEEP_US	10000
#define YT921X_POLL_TIMEOUT_US	100000

/* The interval should be small enough to avoid overflow of 32bit MIBs.
 *
 * Until we can read MIBs from stats64 call directly (i.e. sleep
 * there), we have to poll stats more frequently then it is actually needed.
 * For overflow protection, normally, 100 sec interval should have been OK.
 */
#define YT921X_STATS_INTERVAL_JIFFIES	(3 * HZ)

struct yt921x_reg_mdio {
	struct mii_bus *bus;
	int addr;
	/* SWITCH_ID_1 / SWITCH_ID_0 of the device
	 *
	 * This is a way to multiplex multiple devices on the same MII phyaddr
	 * and should be configurable in DT. However, MDIO core simply doesn't
	 * allow multiple devices over one reg addr, so this is a fixed value
	 * for now until a solution is found.
	 *
	 * Keep this because we need switchid to form MII regaddrs anyway.
	 */
	unsigned char switchid;
};

/* TODO: SPI/I2C */

#define to_yt921x_priv(_ds) container_of_const(_ds, struct yt921x_priv, ds)
#define to_device(priv) ((priv)->ds.dev)

static int yt921x_reg_read(struct yt921x_priv *priv, u32 reg, u32 *valp)
{
	WARN_ON(!mutex_is_locked(&priv->reg_lock));

	return priv->reg_ops->read(priv->reg_ctx, reg, valp);
}

static int yt921x_reg_write(struct yt921x_priv *priv, u32 reg, u32 val)
{
	WARN_ON(!mutex_is_locked(&priv->reg_lock));

	return priv->reg_ops->write(priv->reg_ctx, reg, val);
}

static int
yt921x_reg_wait(struct yt921x_priv *priv, u32 reg, u32 mask, u32 *valp)
{
	u32 val;
	int res;
	int ret;

	ret = read_poll_timeout(yt921x_reg_read, res,
				res || (val & mask) == *valp,
				YT921X_POLL_SLEEP_US, YT921X_POLL_TIMEOUT_US,
				false, priv, reg, &val);
	if (ret)
		return ret;
	if (res)
		return res;

	*valp = val;
	return 0;
}

static int
yt921x_reg_update_bits(struct yt921x_priv *priv, u32 reg, u32 mask, u32 val)
{
	int res;
	u32 v;
	u32 u;

	res = yt921x_reg_read(priv, reg, &v);
	if (res)
		return res;

	u = v;
	u &= ~mask;
	u |= val;
	if (u == v)
		return 0;

	return yt921x_reg_write(priv, reg, u);
}

static int yt921x_reg_set_bits(struct yt921x_priv *priv, u32 reg, u32 mask)
{
	return yt921x_reg_update_bits(priv, reg, 0, mask);
}

static int yt921x_reg_clear_bits(struct yt921x_priv *priv, u32 reg, u32 mask)
{
	return yt921x_reg_update_bits(priv, reg, mask, 0);
}

static int
yt921x_reg_toggle_bits(struct yt921x_priv *priv, u32 reg, u32 mask, bool set)
{
	return yt921x_reg_update_bits(priv, reg, mask, !set ? 0 : mask);
}

/* Some registers, like VLANn_CTRL, should always be written in 64-bit, even if
 * you are to write only the lower / upper 32 bits.
 *
 * There is no such restriction for reading, but we still provide 64-bit read
 * wrappers so that we always handle u64 values.
 */

static int yt921x_reg64_read(struct yt921x_priv *priv, u32 reg, u64 *valp)
{
	u32 lo;
	u32 hi;
	int res;

	res = yt921x_reg_read(priv, reg, &lo);
	if (res)
		return res;
	res = yt921x_reg_read(priv, reg + 4, &hi);
	if (res)
		return res;

	*valp = ((u64)hi << 32) | lo;
	return 0;
}

static int yt921x_reg64_write(struct yt921x_priv *priv, u32 reg, u64 val)
{
	int res;

	res = yt921x_reg_write(priv, reg, (u32)val);
	if (res)
		return res;
	return yt921x_reg_write(priv, reg + 4, (u32)(val >> 32));
}

static int
yt921x_reg64_update_bits(struct yt921x_priv *priv, u32 reg, u64 mask, u64 val)
{
	int res;
	u64 v;
	u64 u;

	res = yt921x_reg64_read(priv, reg, &v);
	if (res)
		return res;

	u = v;
	u &= ~mask;
	u |= val;
	if (u == v)
		return 0;

	return yt921x_reg64_write(priv, reg, u);
}

static int yt921x_reg64_clear_bits(struct yt921x_priv *priv, u32 reg, u64 mask)
{
	return yt921x_reg64_update_bits(priv, reg, mask, 0);
}

static int yt921x_reg_mdio_read(void *context, u32 reg, u32 *valp)
{
	struct yt921x_reg_mdio *mdio = context;
	struct mii_bus *bus = mdio->bus;
	int addr = mdio->addr;
	u32 reg_addr;
	u32 reg_data;
	u32 val;
	int res;

	/* Hold the mdio bus lock to avoid (un)locking for 4 times */
	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);

	reg_addr = YT921X_SMI_SWITCHID(mdio->switchid) | YT921X_SMI_ADDR |
		   YT921X_SMI_READ;
	res = __mdiobus_write(bus, addr, reg_addr, (u16)(reg >> 16));
	if (res)
		goto end;
	res = __mdiobus_write(bus, addr, reg_addr, (u16)reg);
	if (res)
		goto end;

	reg_data = YT921X_SMI_SWITCHID(mdio->switchid) | YT921X_SMI_DATA |
		   YT921X_SMI_READ;
	res = __mdiobus_read(bus, addr, reg_data);
	if (res < 0)
		goto end;
	val = (u16)res;
	res = __mdiobus_read(bus, addr, reg_data);
	if (res < 0)
		goto end;
	val = (val << 16) | (u16)res;

	*valp = val;
	res = 0;

end:
	mutex_unlock(&bus->mdio_lock);
	return res;
}

static int yt921x_reg_mdio_write(void *context, u32 reg, u32 val)
{
	struct yt921x_reg_mdio *mdio = context;
	struct mii_bus *bus = mdio->bus;
	int addr = mdio->addr;
	u32 reg_addr;
	u32 reg_data;
	int res;

	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);

	reg_addr = YT921X_SMI_SWITCHID(mdio->switchid) | YT921X_SMI_ADDR |
		   YT921X_SMI_WRITE;
	res = __mdiobus_write(bus, addr, reg_addr, (u16)(reg >> 16));
	if (res)
		goto end;
	res = __mdiobus_write(bus, addr, reg_addr, (u16)reg);
	if (res)
		goto end;

	reg_data = YT921X_SMI_SWITCHID(mdio->switchid) | YT921X_SMI_DATA |
		   YT921X_SMI_WRITE;
	res = __mdiobus_write(bus, addr, reg_data, (u16)(val >> 16));
	if (res)
		goto end;
	res = __mdiobus_write(bus, addr, reg_data, (u16)val);
	if (res)
		goto end;

	res = 0;

end:
	mutex_unlock(&bus->mdio_lock);
	return res;
}

static const struct yt921x_reg_ops yt921x_reg_ops_mdio = {
	.read = yt921x_reg_mdio_read,
	.write = yt921x_reg_mdio_write,
};

/* TODO: SPI/I2C */

static int yt921x_intif_wait(struct yt921x_priv *priv)
{
	u32 val = 0;

	return yt921x_reg_wait(priv, YT921X_INT_MBUS_OP, YT921X_MBUS_OP_START,
			       &val);
}

static int
yt921x_intif_read(struct yt921x_priv *priv, int port, int reg, u16 *valp)
{
	struct device *dev = to_device(priv);
	u32 mask;
	u32 ctrl;
	u32 val;
	int res;

	res = yt921x_intif_wait(priv);
	if (res)
		return res;

	mask = YT921X_MBUS_CTRL_PORT_M | YT921X_MBUS_CTRL_REG_M |
	       YT921X_MBUS_CTRL_OP_M;
	ctrl = YT921X_MBUS_CTRL_PORT(port) | YT921X_MBUS_CTRL_REG(reg) |
	       YT921X_MBUS_CTRL_READ;
	res = yt921x_reg_update_bits(priv, YT921X_INT_MBUS_CTRL, mask, ctrl);
	if (res)
		return res;
	res = yt921x_reg_write(priv, YT921X_INT_MBUS_OP, YT921X_MBUS_OP_START);
	if (res)
		return res;

	res = yt921x_intif_wait(priv);
	if (res)
		return res;
	res = yt921x_reg_read(priv, YT921X_INT_MBUS_DIN, &val);
	if (res)
		return res;

	if ((u16)val != val)
		dev_info(dev,
			 "%s: port %d, reg 0x%x: Expected u16, got 0x%08x\n",
			 __func__, port, reg, val);
	*valp = (u16)val;
	return 0;
}

static int
yt921x_intif_write(struct yt921x_priv *priv, int port, int reg, u16 val)
{
	u32 mask;
	u32 ctrl;
	int res;

	res = yt921x_intif_wait(priv);
	if (res)
		return res;

	mask = YT921X_MBUS_CTRL_PORT_M | YT921X_MBUS_CTRL_REG_M |
	       YT921X_MBUS_CTRL_OP_M;
	ctrl = YT921X_MBUS_CTRL_PORT(port) | YT921X_MBUS_CTRL_REG(reg) |
	       YT921X_MBUS_CTRL_WRITE;
	res = yt921x_reg_update_bits(priv, YT921X_INT_MBUS_CTRL, mask, ctrl);
	if (res)
		return res;
	res = yt921x_reg_write(priv, YT921X_INT_MBUS_DOUT, val);
	if (res)
		return res;
	res = yt921x_reg_write(priv, YT921X_INT_MBUS_OP, YT921X_MBUS_OP_START);
	if (res)
		return res;

	return yt921x_intif_wait(priv);
}

static int yt921x_mbus_int_read(struct mii_bus *mbus, int port, int reg)
{
	struct yt921x_priv *priv = mbus->priv;
	u16 val;
	int res;

	if (port >= YT921X_PORT_NUM)
		return U16_MAX;

	mutex_lock(&priv->reg_lock);
	res = yt921x_intif_read(priv, port, reg, &val);
	mutex_unlock(&priv->reg_lock);

	if (res)
		return res;
	return val;
}

static int
yt921x_mbus_int_write(struct mii_bus *mbus, int port, int reg, u16 data)
{
	struct yt921x_priv *priv = mbus->priv;
	int res;

	if (port >= YT921X_PORT_NUM)
		return -ENODEV;

	mutex_lock(&priv->reg_lock);
	res = yt921x_intif_write(priv, port, reg, data);
	mutex_unlock(&priv->reg_lock);

	return res;
}

static int
yt921x_mbus_int_init(struct yt921x_priv *priv, struct device_node *mnp)
{
	struct device *dev = to_device(priv);
	struct mii_bus *mbus;
	int res;

	mbus = devm_mdiobus_alloc(dev);
	if (!mbus)
		return -ENOMEM;

	mbus->name = "YT921x internal MDIO bus";
	snprintf(mbus->id, MII_BUS_ID_SIZE, "%s", dev_name(dev));
	mbus->priv = priv;
	mbus->read = yt921x_mbus_int_read;
	mbus->write = yt921x_mbus_int_write;
	mbus->parent = dev;
	mbus->phy_mask = (u32)~GENMASK(YT921X_PORT_NUM - 1, 0);

	res = devm_of_mdiobus_register(dev, mbus, mnp);
	if (res)
		return res;

	priv->mbus_int = mbus;

	return 0;
}

static int yt921x_extif_wait(struct yt921x_priv *priv)
{
	u32 val = 0;

	return yt921x_reg_wait(priv, YT921X_EXT_MBUS_OP, YT921X_MBUS_OP_START,
			       &val);
}

static int
yt921x_extif_read(struct yt921x_priv *priv, int port, int reg, u16 *valp)
{
	struct device *dev = to_device(priv);
	u32 mask;
	u32 ctrl;
	u32 val;
	int res;

	res = yt921x_extif_wait(priv);
	if (res)
		return res;

	mask = YT921X_MBUS_CTRL_PORT_M | YT921X_MBUS_CTRL_REG_M |
	       YT921X_MBUS_CTRL_TYPE_M | YT921X_MBUS_CTRL_OP_M;
	ctrl = YT921X_MBUS_CTRL_PORT(port) | YT921X_MBUS_CTRL_REG(reg) |
	       YT921X_MBUS_CTRL_TYPE_C22 | YT921X_MBUS_CTRL_READ;
	res = yt921x_reg_update_bits(priv, YT921X_EXT_MBUS_CTRL, mask, ctrl);
	if (res)
		return res;
	res = yt921x_reg_write(priv, YT921X_EXT_MBUS_OP, YT921X_MBUS_OP_START);
	if (res)
		return res;

	res = yt921x_extif_wait(priv);
	if (res)
		return res;
	res = yt921x_reg_read(priv, YT921X_EXT_MBUS_DIN, &val);
	if (res)
		return res;

	if ((u16)val != val)
		dev_info(dev,
			 "%s: port %d, reg 0x%x: Expected u16, got 0x%08x\n",
			 __func__, port, reg, val);
	*valp = (u16)val;
	return 0;
}

static int
yt921x_extif_write(struct yt921x_priv *priv, int port, int reg, u16 val)
{
	u32 mask;
	u32 ctrl;
	int res;

	res = yt921x_extif_wait(priv);
	if (res)
		return res;

	mask = YT921X_MBUS_CTRL_PORT_M | YT921X_MBUS_CTRL_REG_M |
	       YT921X_MBUS_CTRL_TYPE_M | YT921X_MBUS_CTRL_OP_M;
	ctrl = YT921X_MBUS_CTRL_PORT(port) | YT921X_MBUS_CTRL_REG(reg) |
	       YT921X_MBUS_CTRL_TYPE_C22 | YT921X_MBUS_CTRL_WRITE;
	res = yt921x_reg_update_bits(priv, YT921X_EXT_MBUS_CTRL, mask, ctrl);
	if (res)
		return res;
	res = yt921x_reg_write(priv, YT921X_EXT_MBUS_DOUT, val);
	if (res)
		return res;
	res = yt921x_reg_write(priv, YT921X_EXT_MBUS_OP, YT921X_MBUS_OP_START);
	if (res)
		return res;

	return yt921x_extif_wait(priv);
}

static int yt921x_mbus_ext_read(struct mii_bus *mbus, int port, int reg)
{
	struct yt921x_priv *priv = mbus->priv;
	u16 val;
	int res;

	mutex_lock(&priv->reg_lock);
	res = yt921x_extif_read(priv, port, reg, &val);
	mutex_unlock(&priv->reg_lock);

	if (res)
		return res;
	return val;
}

static int
yt921x_mbus_ext_write(struct mii_bus *mbus, int port, int reg, u16 data)
{
	struct yt921x_priv *priv = mbus->priv;
	int res;

	mutex_lock(&priv->reg_lock);
	res = yt921x_extif_write(priv, port, reg, data);
	mutex_unlock(&priv->reg_lock);

	return res;
}

static int
yt921x_mbus_ext_init(struct yt921x_priv *priv, struct device_node *mnp)
{
	struct device *dev = to_device(priv);
	struct mii_bus *mbus;
	int res;

	mbus = devm_mdiobus_alloc(dev);
	if (!mbus)
		return -ENOMEM;

	mbus->name = "YT921x external MDIO bus";
	snprintf(mbus->id, MII_BUS_ID_SIZE, "%s@ext", dev_name(dev));
	mbus->priv = priv;
	/* TODO: c45? */
	mbus->read = yt921x_mbus_ext_read;
	mbus->write = yt921x_mbus_ext_write;
	mbus->parent = dev;

	res = devm_of_mdiobus_register(dev, mbus, mnp);
	if (res)
		return res;

	priv->mbus_ext = mbus;

	return 0;
}

/* Read and handle overflow of 32bit MIBs. MIB buffer must be zeroed before. */
static int yt921x_read_mib(struct yt921x_priv *priv, int port)
{
	struct yt921x_port *pp = &priv->ports[port];
	struct device *dev = to_device(priv);
	struct yt921x_mib *mib = &pp->mib;
	int res = 0;

	/* Reading of yt921x_port::mib is not protected by a lock and it's vain
	 * to keep its consistency, since we have to read registers one by one
	 * and there is no way to make a snapshot of MIB stats.
	 *
	 * Writing (by this function only) is and should be protected by
	 * reg_lock.
	 */

	for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) {
		const struct yt921x_mib_desc *desc = &yt921x_mib_descs[i];
		u32 reg = YT921X_MIBn_DATA0(port) + desc->offset;
		u64 *valp = &((u64 *)mib)[i];
		u64 val = *valp;
		u32 val0;
		u32 val1;

		res = yt921x_reg_read(priv, reg, &val0);
		if (res)
			break;

		if (desc->size <= 1) {
			if (val < (u32)val)
				/* overflow */
				val += (u64)U32_MAX + 1;
			val &= ~U32_MAX;
			val |= val0;
		} else {
			res = yt921x_reg_read(priv, reg + 4, &val1);
			if (res)
				break;
			val = ((u64)val1 << 32) | val0;
		}

		WRITE_ONCE(*valp, val);
	}

	pp->rx_frames = mib->rx_64byte + mib->rx_65_127byte +
			mib->rx_128_255byte + mib->rx_256_511byte +
			mib->rx_512_1023byte + mib->rx_1024_1518byte +
			mib->rx_jumbo;
	pp->tx_frames = mib->tx_64byte + mib->tx_65_127byte +
			mib->tx_128_255byte + mib->tx_256_511byte +
			mib->tx_512_1023byte + mib->tx_1024_1518byte +
			mib->tx_jumbo;

	if (res)
		dev_err(dev, "Failed to %s port %d: %i\n", "read stats for",
			port, res);
	return res;
}

static void yt921x_poll_mib(struct work_struct *work)
{
	struct yt921x_port *pp = container_of_const(work, struct yt921x_port,
						    mib_read.work);
	struct yt921x_priv *priv = (void *)(pp - pp->index) -
				   offsetof(struct yt921x_priv, ports);
	unsigned long delay = YT921X_STATS_INTERVAL_JIFFIES;
	int port = pp->index;
	int res;

	mutex_lock(&priv->reg_lock);
	res = yt921x_read_mib(priv, port);
	mutex_unlock(&priv->reg_lock);
	if (res)
		delay *= 4;

	schedule_delayed_work(&pp->mib_read, delay);
}

static void
yt921x_dsa_get_strings(struct dsa_switch *ds, int port, u32 stringset,
		       uint8_t *data)
{
	if (stringset != ETH_SS_STATS)
		return;

	for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) {
		const struct yt921x_mib_desc *desc = &yt921x_mib_descs[i];

		if (desc->name)
			ethtool_puts(&data, desc->name);
	}
}

static void
yt921x_dsa_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *data)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	struct yt921x_port *pp = &priv->ports[port];
	struct yt921x_mib *mib = &pp->mib;
	size_t j;

	mutex_lock(&priv->reg_lock);
	yt921x_read_mib(priv, port);
	mutex_unlock(&priv->reg_lock);

	j = 0;
	for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) {
		const struct yt921x_mib_desc *desc = &yt921x_mib_descs[i];

		if (!desc->name)
			continue;

		data[j] = ((u64 *)mib)[i];
		j++;
	}
}

static int yt921x_dsa_get_sset_count(struct dsa_switch *ds, int port, int sset)
{
	int cnt = 0;

	if (sset != ETH_SS_STATS)
		return 0;

	for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) {
		const struct yt921x_mib_desc *desc = &yt921x_mib_descs[i];

		if (desc->name)
			cnt++;
	}

	return cnt;
}

static void
yt921x_dsa_get_eth_mac_stats(struct dsa_switch *ds, int port,
			     struct ethtool_eth_mac_stats *mac_stats)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	struct yt921x_port *pp = &priv->ports[port];
	struct yt921x_mib *mib = &pp->mib;

	mutex_lock(&priv->reg_lock);
	yt921x_read_mib(priv, port);
	mutex_unlock(&priv->reg_lock);

	mac_stats->FramesTransmittedOK = pp->tx_frames;
	mac_stats->SingleCollisionFrames = mib->tx_single_collisions;
	mac_stats->MultipleCollisionFrames = mib->tx_multiple_collisions;
	mac_stats->FramesReceivedOK = pp->rx_frames;
	mac_stats->FrameCheckSequenceErrors = mib->rx_crc_errors;
	mac_stats->AlignmentErrors = mib->rx_alignment_errors;
	mac_stats->OctetsTransmittedOK = mib->tx_good_bytes;
	mac_stats->FramesWithDeferredXmissions = mib->tx_deferred;
	mac_stats->LateCollisions = mib->tx_late_collisions;
	mac_stats->FramesAbortedDueToXSColls = mib->tx_aborted_errors;
	/* mac_stats->FramesLostDueToIntMACXmitError */
	/* mac_stats->CarrierSenseErrors */
	mac_stats->OctetsReceivedOK = mib->rx_good_bytes;
	/* mac_stats->FramesLostDueToIntMACRcvError */
	mac_stats->MulticastFramesXmittedOK = mib->tx_multicast;
	mac_stats->BroadcastFramesXmittedOK = mib->tx_broadcast;
	/* mac_stats->FramesWithExcessiveDeferral */
	mac_stats->MulticastFramesReceivedOK = mib->rx_multicast;
	mac_stats->BroadcastFramesReceivedOK = mib->rx_broadcast;
	/* mac_stats->InRangeLengthErrors */
	/* mac_stats->OutOfRangeLengthField */
	mac_stats->FrameTooLongErrors = mib->rx_oversize_errors;
}

static void
yt921x_dsa_get_eth_ctrl_stats(struct dsa_switch *ds, int port,
			      struct ethtool_eth_ctrl_stats *ctrl_stats)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	struct yt921x_port *pp = &priv->ports[port];
	struct yt921x_mib *mib = &pp->mib;

	mutex_lock(&priv->reg_lock);
	yt921x_read_mib(priv, port);
	mutex_unlock(&priv->reg_lock);

	ctrl_stats->MACControlFramesTransmitted = mib->tx_pause;
	ctrl_stats->MACControlFramesReceived = mib->rx_pause;
	/* ctrl_stats->UnsupportedOpcodesReceived */
}

static const struct ethtool_rmon_hist_range yt921x_rmon_ranges[] = {
	{ 0, 64 },
	{ 65, 127 },
	{ 128, 255 },
	{ 256, 511 },
	{ 512, 1023 },
	{ 1024, 1518 },
	{ 1519, YT921X_FRAME_SIZE_MAX },
	{}
};

static void
yt921x_dsa_get_rmon_stats(struct dsa_switch *ds, int port,
			  struct ethtool_rmon_stats *rmon_stats,
			  const struct ethtool_rmon_hist_range **ranges)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	struct yt921x_port *pp = &priv->ports[port];
	struct yt921x_mib *mib = &pp->mib;

	mutex_lock(&priv->reg_lock);
	yt921x_read_mib(priv, port);
	mutex_unlock(&priv->reg_lock);

	*ranges = yt921x_rmon_ranges;

	rmon_stats->undersize_pkts = mib->rx_undersize_errors;
	rmon_stats->oversize_pkts = mib->rx_oversize_errors;
	rmon_stats->fragments = mib->rx_alignment_errors;
	/* rmon_stats->jabbers */

	rmon_stats->hist[0] = mib->rx_64byte;
	rmon_stats->hist[1] = mib->rx_65_127byte;
	rmon_stats->hist[2] = mib->rx_128_255byte;
	rmon_stats->hist[3] = mib->rx_256_511byte;
	rmon_stats->hist[4] = mib->rx_512_1023byte;
	rmon_stats->hist[5] = mib->rx_1024_1518byte;
	rmon_stats->hist[6] = mib->rx_jumbo;

	rmon_stats->hist_tx[0] = mib->tx_64byte;
	rmon_stats->hist_tx[1] = mib->tx_65_127byte;
	rmon_stats->hist_tx[2] = mib->tx_128_255byte;
	rmon_stats->hist_tx[3] = mib->tx_256_511byte;
	rmon_stats->hist_tx[4] = mib->tx_512_1023byte;
	rmon_stats->hist_tx[5] = mib->tx_1024_1518byte;
	rmon_stats->hist_tx[6] = mib->tx_jumbo;
}

static void
yt921x_dsa_get_stats64(struct dsa_switch *ds, int port,
		       struct rtnl_link_stats64 *stats)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	struct yt921x_port *pp = &priv->ports[port];
	struct yt921x_mib *mib = &pp->mib;

	stats->rx_length_errors = mib->rx_undersize_errors +
				  mib->rx_fragment_errors;
	stats->rx_over_errors = mib->rx_oversize_errors;
	stats->rx_crc_errors = mib->rx_crc_errors;
	stats->rx_frame_errors = mib->rx_alignment_errors;
	/* stats->rx_fifo_errors */
	/* stats->rx_missed_errors */

	stats->tx_aborted_errors = mib->tx_aborted_errors;
	/* stats->tx_carrier_errors */
	stats->tx_fifo_errors = mib->tx_undersize_errors;
	/* stats->tx_heartbeat_errors */
	stats->tx_window_errors = mib->tx_late_collisions;

	stats->rx_packets = pp->rx_frames;
	stats->tx_packets = pp->tx_frames;
	stats->rx_bytes = mib->rx_good_bytes - ETH_FCS_LEN * stats->rx_packets;
	stats->tx_bytes = mib->tx_good_bytes - ETH_FCS_LEN * stats->tx_packets;
	stats->rx_errors = stats->rx_length_errors + stats->rx_over_errors +
			   stats->rx_crc_errors + stats->rx_frame_errors;
	stats->tx_errors = stats->tx_aborted_errors + stats->tx_fifo_errors +
			   stats->tx_window_errors;
	stats->rx_dropped = mib->rx_dropped;
	/* stats->tx_dropped */
	stats->multicast = mib->rx_multicast;
	stats->collisions = mib->tx_collisions;
}

static void
yt921x_dsa_get_pause_stats(struct dsa_switch *ds, int port,
			   struct ethtool_pause_stats *pause_stats)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	struct yt921x_port *pp = &priv->ports[port];
	struct yt921x_mib *mib = &pp->mib;

	mutex_lock(&priv->reg_lock);
	yt921x_read_mib(priv, port);
	mutex_unlock(&priv->reg_lock);

	pause_stats->tx_pause_frames = mib->tx_pause;
	pause_stats->rx_pause_frames = mib->rx_pause;
}

static int
yt921x_set_eee(struct yt921x_priv *priv, int port, struct ethtool_keee *e)
{
	/* Poor datasheet for EEE operations; don't ask if you are confused */

	bool enable = e->eee_enabled;
	u16 new_mask;
	int res;

	/* Enable / disable global EEE */
	new_mask = priv->eee_ports_mask;
	new_mask &= ~BIT(port);
	new_mask |= !enable ? 0 : BIT(port);

	if (!!new_mask != !!priv->eee_ports_mask) {
		res = yt921x_reg_toggle_bits(priv, YT921X_PON_STRAP_FUNC,
					     YT921X_PON_STRAP_EEE, !!new_mask);
		if (res)
			return res;
		res = yt921x_reg_toggle_bits(priv, YT921X_PON_STRAP_VAL,
					     YT921X_PON_STRAP_EEE, !!new_mask);
		if (res)
			return res;
	}

	priv->eee_ports_mask = new_mask;

	/* Enable / disable port EEE */
	res = yt921x_reg_toggle_bits(priv, YT921X_EEE_CTRL,
				     YT921X_EEE_CTRL_ENn(port), enable);
	if (res)
		return res;
	res = yt921x_reg_toggle_bits(priv, YT921X_EEEn_VAL(port),
				     YT921X_EEE_VAL_DATA, enable);
	if (res)
		return res;

	return 0;
}

static int
yt921x_dsa_set_mac_eee(struct dsa_switch *ds, int port, struct ethtool_keee *e)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	int res;

	mutex_lock(&priv->reg_lock);
	res = yt921x_set_eee(priv, port, e);
	mutex_unlock(&priv->reg_lock);

	return res;
}

static int
yt921x_dsa_port_change_mtu(struct dsa_switch *ds, int port, int new_mtu)
{
	/* Only serves as packet filter, since the frame size is always set to
	 * maximum after reset
	 */

	struct yt921x_priv *priv = to_yt921x_priv(ds);
	struct dsa_port *dp = dsa_to_port(ds, port);
	int frame_size;
	int res;

	frame_size = new_mtu + ETH_HLEN + ETH_FCS_LEN;
	if (dsa_port_is_cpu(dp))
		frame_size += YT921X_TAG_LEN;

	mutex_lock(&priv->reg_lock);
	res = yt921x_reg_update_bits(priv, YT921X_MACn_FRAME(port),
				     YT921X_MAC_FRAME_SIZE_M,
				     YT921X_MAC_FRAME_SIZE(frame_size));
	mutex_unlock(&priv->reg_lock);

	return res;
}

static int yt921x_dsa_port_max_mtu(struct dsa_switch *ds, int port)
{
	/* Only called for user ports, exclude tag len here */
	return YT921X_FRAME_SIZE_MAX - ETH_HLEN - ETH_FCS_LEN - YT921X_TAG_LEN;
}

static int
yt921x_mirror_del(struct yt921x_priv *priv, int port, bool ingress)
{
	u32 mask;

	if (ingress)
		mask = YT921X_MIRROR_IGR_PORTn(port);
	else
		mask = YT921X_MIRROR_EGR_PORTn(port);
	return yt921x_reg_clear_bits(priv, YT921X_MIRROR, mask);
}

static int
yt921x_mirror_add(struct yt921x_priv *priv, int port, bool ingress,
		  int to_local_port, struct netlink_ext_ack *extack)
{
	u32 srcs;
	u32 ctrl;
	u32 val;
	u32 dst;
	int res;

	if (ingress)
		srcs = YT921X_MIRROR_IGR_PORTn(port);
	else
		srcs = YT921X_MIRROR_EGR_PORTn(port);
	dst = YT921X_MIRROR_PORT(to_local_port);

	res = yt921x_reg_read(priv, YT921X_MIRROR, &val);
	if (res)
		return res;

	/* other mirror tasks & different dst port -> conflict */
	if ((val & ~srcs & (YT921X_MIRROR_EGR_PORTS_M |
			    YT921X_MIRROR_IGR_PORTS_M)) &&
	    (val & YT921X_MIRROR_PORT_M) != dst) {
		NL_SET_ERR_MSG_MOD(extack,
				   "Sniffer port is already configured, delete existing rules & retry");
		return -EBUSY;
	}

	ctrl = val & ~YT921X_MIRROR_PORT_M;
	ctrl |= srcs;
	ctrl |= dst;

	if (ctrl == val)
		return 0;

	return yt921x_reg_write(priv, YT921X_MIRROR, ctrl);
}

static void
yt921x_dsa_port_mirror_del(struct dsa_switch *ds, int port,
			   struct dsa_mall_mirror_tc_entry *mirror)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	struct device *dev = to_device(priv);
	int res;

	mutex_lock(&priv->reg_lock);
	res = yt921x_mirror_del(priv, port, mirror->ingress);
	mutex_unlock(&priv->reg_lock);

	if (res)
		dev_err(dev, "Failed to %s port %d: %i\n", "unmirror",
			port, res);
}

static int
yt921x_dsa_port_mirror_add(struct dsa_switch *ds, int port,
			   struct dsa_mall_mirror_tc_entry *mirror,
			   bool ingress, struct netlink_ext_ack *extack)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	int res;

	mutex_lock(&priv->reg_lock);
	res = yt921x_mirror_add(priv, port, ingress,
				mirror->to_local_port, extack);
	mutex_unlock(&priv->reg_lock);

	return res;
}

static int yt921x_fdb_wait(struct yt921x_priv *priv, u32 *valp)
{
	struct device *dev = to_device(priv);
	u32 val = YT921X_FDB_RESULT_DONE;
	int res;

	res = yt921x_reg_wait(priv, YT921X_FDB_RESULT, YT921X_FDB_RESULT_DONE,
			      &val);
	if (res) {
		dev_err(dev, "FDB probably stuck\n");
		return res;
	}

	*valp = val;
	return 0;
}

static int
yt921x_fdb_in01(struct yt921x_priv *priv, const unsigned char *addr,
		u16 vid, u32 ctrl1)
{
	u32 ctrl;
	int res;

	ctrl = (addr[0] << 24) | (addr[1] << 16) | (addr[2] << 8) | addr[3];
	res = yt921x_reg_write(priv, YT921X_FDB_IN0, ctrl);
	if (res)
		return res;

	ctrl = ctrl1 | YT921X_FDB_IO1_FID(vid) | (addr[4] << 8) | addr[5];
	return yt921x_reg_write(priv, YT921X_FDB_IN1, ctrl);
}

static int
yt921x_fdb_has(struct yt921x_priv *priv, const unsigned char *addr, u16 vid,
	       u16 *indexp)
{
	u32 ctrl;
	u32 val;
	int res;

	res = yt921x_fdb_in01(priv, addr, vid, 0);
	if (res)
		return res;

	ctrl = 0;
	res = yt921x_reg_write(priv, YT921X_FDB_IN2, ctrl);
	if (res)
		return res;

	ctrl = YT921X_FDB_OP_OP_GET_ONE | YT921X_FDB_OP_START;
	res = yt921x_reg_write(priv, YT921X_FDB_OP, ctrl);
	if (res)
		return res;

	res = yt921x_fdb_wait(priv, &val);
	if (res)
		return res;
	if (val & YT921X_FDB_RESULT_NOTFOUND) {
		*indexp = YT921X_FDB_NUM;
		return 0;
	}

	*indexp = FIELD_GET(YT921X_FDB_RESULT_INDEX_M, val);
	return 0;
}

static int
yt921x_fdb_read(struct yt921x_priv *priv, unsigned char *addr, u16 *vidp,
		u16 *ports_maskp, u16 *indexp, u8 *statusp)
{
	struct device *dev = to_device(priv);
	u16 index;
	u32 data0;
	u32 data1;
	u32 data2;
	u32 val;
	int res;

	res = yt921x_fdb_wait(priv, &val);
	if (res)
		return res;
	if (val & YT921X_FDB_RESULT_NOTFOUND) {
		*ports_maskp = 0;
		return 0;
	}
	index = FIELD_GET(YT921X_FDB_RESULT_INDEX_M, val);

	res = yt921x_reg_read(priv, YT921X_FDB_OUT1, &data1);
	if (res)
		return res;
	if ((data1 & YT921X_FDB_IO1_STATUS_M) ==
	    YT921X_FDB_IO1_STATUS_INVALID) {
		*ports_maskp = 0;
		return 0;
	}

	res = yt921x_reg_read(priv, YT921X_FDB_OUT0, &data0);
	if (res)
		return res;
	res = yt921x_reg_read(priv, YT921X_FDB_OUT2, &data2);
	if (res)
		return res;

	addr[0] = data0 >> 24;
	addr[1] = data0 >> 16;
	addr[2] = data0 >> 8;
	addr[3] = data0;
	addr[4] = data1 >> 8;
	addr[5] = data1;
	*vidp = FIELD_GET(YT921X_FDB_IO1_FID_M, data1);
	*indexp = index;
	*ports_maskp = FIELD_GET(YT921X_FDB_IO2_EGR_PORTS_M, data2);
	*statusp = FIELD_GET(YT921X_FDB_IO1_STATUS_M, data1);

	dev_dbg(dev,
		"%s: index 0x%x, mac %02x:%02x:%02x:%02x:%02x:%02x, vid %d, ports 0x%x, status %d\n",
		__func__, *indexp, addr[0], addr[1], addr[2], addr[3],
		addr[4], addr[5], *vidp, *ports_maskp, *statusp);
	return 0;
}

static int
yt921x_fdb_dump(struct yt921x_priv *priv, u16 ports_mask,
		dsa_fdb_dump_cb_t *cb, void *data)
{
	unsigned char addr[ETH_ALEN];
	u8 status;
	u16 pmask;
	u16 index;
	u32 ctrl;
	u16 vid;
	int res;

	ctrl = YT921X_FDB_OP_INDEX(0) | YT921X_FDB_OP_MODE_INDEX |
	       YT921X_FDB_OP_OP_GET_ONE | YT921X_FDB_OP_START;
	res = yt921x_reg_write(priv, YT921X_FDB_OP, ctrl);
	if (res)
		return res;
	res = yt921x_fdb_read(priv, addr, &vid, &pmask, &index, &status);
	if (res)
		return res;
	if ((pmask & ports_mask) && !is_multicast_ether_addr(addr)) {
		res = cb(addr, vid,
			 status == YT921X_FDB_ENTRY_STATUS_STATIC, data);
		if (res)
			return res;
	}

	ctrl = YT921X_FDB_IO2_EGR_PORTS(ports_mask);
	res = yt921x_reg_write(priv, YT921X_FDB_IN2, ctrl);
	if (res)
		return res;

	index = 0;
	do {
		ctrl = YT921X_FDB_OP_INDEX(index) | YT921X_FDB_OP_MODE_INDEX |
		       YT921X_FDB_OP_NEXT_TYPE_UCAST_PORT |
		       YT921X_FDB_OP_OP_GET_NEXT | YT921X_FDB_OP_START;
		res = yt921x_reg_write(priv, YT921X_FDB_OP, ctrl);
		if (res)
			return res;

		res = yt921x_fdb_read(priv, addr, &vid, &pmask, &index,
				      &status);
		if (res)
			return res;
		if (!pmask)
			break;

		if ((pmask & ports_mask) && !is_multicast_ether_addr(addr)) {
			res = cb(addr, vid,
				 status == YT921X_FDB_ENTRY_STATUS_STATIC,
				 data);
			if (res)
				return res;
		}

		/* Never call GET_NEXT with 4095, otherwise it will hang
		 * forever until a reset!
		 */
	} while (index < YT921X_FDB_NUM - 1);

	return 0;
}

static int
yt921x_fdb_flush_raw(struct yt921x_priv *priv, u16 ports_mask, u16 vid,
		     bool flush_static)
{
	u32 ctrl;
	u32 val;
	int res;

	if (vid < 4096) {
		ctrl = YT921X_FDB_IO1_FID(vid);
		res = yt921x_reg_write(priv, YT921X_FDB_IN1, ctrl);
		if (res)
			return res;
	}

	ctrl = YT921X_FDB_IO2_EGR_PORTS(ports_mask);
	res = yt921x_reg_write(priv, YT921X_FDB_IN2, ctrl);
	if (res)
		return res;

	ctrl = YT921X_FDB_OP_OP_FLUSH | YT921X_FDB_OP_START;
	if (vid >= 4096)
		ctrl |= YT921X_FDB_OP_FLUSH_PORT;
	else
		ctrl |= YT921X_FDB_OP_FLUSH_PORT_VID;
	if (flush_static)
		ctrl |= YT921X_FDB_OP_FLUSH_STATIC;
	res = yt921x_reg_write(priv, YT921X_FDB_OP, ctrl);
	if (res)
		return res;

	res = yt921x_fdb_wait(priv, &val);
	if (res)
		return res;

	return 0;
}

static int
yt921x_fdb_flush_port(struct yt921x_priv *priv, int port, bool flush_static)
{
	return yt921x_fdb_flush_raw(priv, BIT(port), 4096, flush_static);
}

static int
yt921x_fdb_add_index_in12(struct yt921x_priv *priv, u16 index, u16 ctrl1,
			  u16 ctrl2)
{
	u32 ctrl;
	u32 val;
	int res;

	res = yt921x_reg_write(priv, YT921X_FDB_IN1, ctrl1);
	if (res)
		return res;
	res = yt921x_reg_write(priv, YT921X_FDB_IN2, ctrl2);
	if (res)
		return res;

	ctrl = YT921X_FDB_OP_INDEX(index) | YT921X_FDB_OP_MODE_INDEX |
	       YT921X_FDB_OP_OP_ADD | YT921X_FDB_OP_START;
	res = yt921x_reg_write(priv, YT921X_FDB_OP, ctrl);
	if (res)
		return res;

	return yt921x_fdb_wait(priv, &val);
}

static int
yt921x_fdb_add(struct yt921x_priv *priv, const unsigned char *addr, u16 vid,
	       u16 ports_mask)
{
	u32 ctrl;
	u32 val;
	int res;

	ctrl = YT921X_FDB_IO1_STATUS_STATIC;
	res = yt921x_fdb_in01(priv, addr, vid, ctrl);
	if (res)
		return res;

	ctrl = YT921X_FDB_IO2_EGR_PORTS(ports_mask);
	res = yt921x_reg_write(priv, YT921X_FDB_IN2, ctrl);
	if (res)
		return res;

	ctrl = YT921X_FDB_OP_OP_ADD | YT921X_FDB_OP_START;
	res = yt921x_reg_write(priv, YT921X_FDB_OP, ctrl);
	if (res)
		return res;

	return yt921x_fdb_wait(priv, &val);
}

static int
yt921x_fdb_leave(struct yt921x_priv *priv, const unsigned char *addr,
		 u16 vid, u16 ports_mask)
{
	u16 index;
	u32 ctrl1;
	u32 ctrl2;
	u32 ctrl;
	u32 val2;
	u32 val;
	int res;

	/* Check for presence */
	res = yt921x_fdb_has(priv, addr, vid, &index);
	if (res)
		return res;
	if (index >= YT921X_FDB_NUM)
		return 0;

	/* Check if action required */
	res = yt921x_reg_read(priv, YT921X_FDB_OUT2, &val2);
	if (res)
		return res;

	ctrl2 = val2 & ~YT921X_FDB_IO2_EGR_PORTS(ports_mask);
	if (ctrl2 == val2)
		return 0;
	if (!(ctrl2 & YT921X_FDB_IO2_EGR_PORTS_M)) {
		ctrl = YT921X_FDB_OP_OP_DEL | YT921X_FDB_OP_START;
		res = yt921x_reg_write(priv, YT921X_FDB_OP, ctrl);
		if (res)
			return res;

		return yt921x_fdb_wait(priv, &val);
	}

	res = yt921x_reg_read(priv, YT921X_FDB_OUT1, &ctrl1);
	if (res)
		return res;

	return yt921x_fdb_add_index_in12(priv, index, ctrl1, ctrl2);
}

static int
yt921x_fdb_join(struct yt921x_priv *priv, const unsigned char *addr, u16 vid,
		u16 ports_mask)
{
	u16 index;
	u32 ctrl1;
	u32 ctrl2;
	u32 val1;
	u32 val2;
	int res;

	/* Check for presence */
	res = yt921x_fdb_has(priv, addr, vid, &index);
	if (res)
		return res;
	if (index >= YT921X_FDB_NUM)
		return yt921x_fdb_add(priv, addr, vid, ports_mask);

	/* Check if action required */
	res = yt921x_reg_read(priv, YT921X_FDB_OUT1, &val1);
	if (res)
		return res;
	res = yt921x_reg_read(priv, YT921X_FDB_OUT2, &val2);
	if (res)
		return res;

	ctrl1 = val1 & ~YT921X_FDB_IO1_STATUS_M;
	ctrl1 |= YT921X_FDB_IO1_STATUS_STATIC;
	ctrl2 = val2 | YT921X_FDB_IO2_EGR_PORTS(ports_mask);
	if (ctrl1 == val1 && ctrl2 == val2)
		return 0;

	return yt921x_fdb_add_index_in12(priv, index, ctrl1, ctrl2);
}

static int
yt921x_dsa_port_fdb_dump(struct dsa_switch *ds, int port,
			 dsa_fdb_dump_cb_t *cb, void *data)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	int res;

	mutex_lock(&priv->reg_lock);
	/* Hardware FDB is shared for fdb and mdb, "bridge fdb show"
	 * only wants to see unicast
	 */
	res = yt921x_fdb_dump(priv, BIT(port), cb, data);
	mutex_unlock(&priv->reg_lock);

	return res;
}

static void yt921x_dsa_port_fast_age(struct dsa_switch *ds, int port)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	struct device *dev = to_device(priv);
	int res;

	mutex_lock(&priv->reg_lock);
	res = yt921x_fdb_flush_port(priv, port, false);
	mutex_unlock(&priv->reg_lock);

	if (res)
		dev_err(dev, "Failed to %s port %d: %i\n", "clear FDB for",
			port, res);
}

static int
yt921x_dsa_set_ageing_time(struct dsa_switch *ds, unsigned int msecs)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	u32 ctrl;
	int res;

	/* AGEING reg is set in 5s step */
	ctrl = clamp(msecs / 5000, 1, U16_MAX);

	mutex_lock(&priv->reg_lock);
	res = yt921x_reg_write(priv, YT921X_AGEING, ctrl);
	mutex_unlock(&priv->reg_lock);

	return res;
}

static int
yt921x_dsa_port_fdb_del(struct dsa_switch *ds, int port,
			const unsigned char *addr, u16 vid, struct dsa_db db)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	int res;

	mutex_lock(&priv->reg_lock);
	res = yt921x_fdb_leave(priv, addr, vid, BIT(port));
	mutex_unlock(&priv->reg_lock);

	return res;
}

static int
yt921x_dsa_port_fdb_add(struct dsa_switch *ds, int port,
			const unsigned char *addr, u16 vid, struct dsa_db db)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	int res;

	mutex_lock(&priv->reg_lock);
	res = yt921x_fdb_join(priv, addr, vid, BIT(port));
	mutex_unlock(&priv->reg_lock);

	return res;
}

static int
yt921x_dsa_port_mdb_del(struct dsa_switch *ds, int port,
			const struct switchdev_obj_port_mdb *mdb,
			struct dsa_db db)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	const unsigned char *addr = mdb->addr;
	u16 vid = mdb->vid;
	int res;

	mutex_lock(&priv->reg_lock);
	res = yt921x_fdb_leave(priv, addr, vid, BIT(port));
	mutex_unlock(&priv->reg_lock);

	return res;
}

static int
yt921x_dsa_port_mdb_add(struct dsa_switch *ds, int port,
			const struct switchdev_obj_port_mdb *mdb,
			struct dsa_db db)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	const unsigned char *addr = mdb->addr;
	u16 vid = mdb->vid;
	int res;

	mutex_lock(&priv->reg_lock);
	res = yt921x_fdb_join(priv, addr, vid, BIT(port));
	mutex_unlock(&priv->reg_lock);

	return res;
}

static int
yt921x_port_set_pvid(struct yt921x_priv *priv, int port, u16 vid)
{
	u32 mask;
	u32 ctrl;

	mask = YT921X_PORT_VLAN_CTRL_CVID_M;
	ctrl = YT921X_PORT_VLAN_CTRL_CVID(vid);
	return yt921x_reg_update_bits(priv, YT921X_PORTn_VLAN_CTRL(port),
				      mask, ctrl);
}

static int
yt921x_vlan_filtering(struct yt921x_priv *priv, int port, bool vlan_filtering)
{
	struct dsa_port *dp = dsa_to_port(&priv->ds, port);
	struct net_device *bdev;
	u16 pvid;
	u32 mask;
	u32 ctrl;
	int res;

	bdev = dsa_port_bridge_dev_get(dp);

	if (!bdev || !vlan_filtering)
		pvid = YT921X_VID_UNWARE;
	else
		br_vlan_get_pvid(bdev, &pvid);
	res = yt921x_port_set_pvid(priv, port, pvid);
	if (res)
		return res;

	mask = YT921X_PORT_VLAN_CTRL1_CVLAN_DROP_TAGGED |
	       YT921X_PORT_VLAN_CTRL1_CVLAN_DROP_UNTAGGED;
	ctrl = 0;
	/* Do not drop tagged frames here; let VLAN_IGR_FILTER do it */
	if (vlan_filtering && !pvid)
		ctrl |= YT921X_PORT_VLAN_CTRL1_CVLAN_DROP_UNTAGGED;
	res = yt921x_reg_update_bits(priv, YT921X_PORTn_VLAN_CTRL1(port),
				     mask, ctrl);
	if (res)
		return res;

	res = yt921x_reg_toggle_bits(priv, YT921X_VLAN_IGR_FILTER,
				     YT921X_VLAN_IGR_FILTER_PORTn(port),
				     vlan_filtering);
	if (res)
		return res;

	/* Turn on / off VLAN awareness */
	mask = YT921X_PORT_IGR_TPIDn_CTAG_M;
	if (!vlan_filtering)
		ctrl = 0;
	else
		ctrl = YT921X_PORT_IGR_TPIDn_CTAG(0);
	res = yt921x_reg_update_bits(priv, YT921X_PORTn_IGR_TPID(port),
				     mask, ctrl);
	if (res)
		return res;

	return 0;
}

static int
yt921x_vlan_del(struct yt921x_priv *priv, int port, u16 vid)
{
	u64 mask64;

	mask64 = YT921X_VLAN_CTRL_PORTS(port) |
		 YT921X_VLAN_CTRL_UNTAG_PORTn(port);

	return yt921x_reg64_clear_bits(priv, YT921X_VLANn_CTRL(vid), mask64);
}

static int
yt921x_vlan_add(struct yt921x_priv *priv, int port, u16 vid, bool untagged)
{
	u64 mask64;
	u64 ctrl64;

	mask64 = YT921X_VLAN_CTRL_PORTn(port) |
		 YT921X_VLAN_CTRL_PORTS(priv->cpu_ports_mask);
	ctrl64 = mask64;

	mask64 |= YT921X_VLAN_CTRL_UNTAG_PORTn(port);
	if (untagged)
		ctrl64 |= YT921X_VLAN_CTRL_UNTAG_PORTn(port);

	return yt921x_reg64_update_bits(priv, YT921X_VLANn_CTRL(vid),
					mask64, ctrl64);
}

static int
yt921x_pvid_clear(struct yt921x_priv *priv, int port)
{
	struct dsa_port *dp = dsa_to_port(&priv->ds, port);
	bool vlan_filtering;
	u32 mask;
	int res;

	vlan_filtering = dsa_port_is_vlan_filtering(dp);

	res = yt921x_port_set_pvid(priv, port,
				   vlan_filtering ? 0 : YT921X_VID_UNWARE);
	if (res)
		return res;

	if (vlan_filtering) {
		mask = YT921X_PORT_VLAN_CTRL1_CVLAN_DROP_UNTAGGED;
		res = yt921x_reg_set_bits(priv, YT921X_PORTn_VLAN_CTRL1(port),
					  mask);
		if (res)
			return res;
	}

	return 0;
}

static int
yt921x_pvid_set(struct yt921x_priv *priv, int port, u16 vid)
{
	struct dsa_port *dp = dsa_to_port(&priv->ds, port);
	bool vlan_filtering;
	u32 mask;
	int res;

	vlan_filtering = dsa_port_is_vlan_filtering(dp);

	if (vlan_filtering) {
		res = yt921x_port_set_pvid(priv, port, vid);
		if (res)
			return res;
	}

	mask = YT921X_PORT_VLAN_CTRL1_CVLAN_DROP_UNTAGGED;
	res = yt921x_reg_clear_bits(priv, YT921X_PORTn_VLAN_CTRL1(port), mask);
	if (res)
		return res;

	return 0;
}

static int
yt921x_dsa_port_vlan_filtering(struct dsa_switch *ds, int port,
			       bool vlan_filtering,
			       struct netlink_ext_ack *extack)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	int res;

	if (dsa_is_cpu_port(ds, port))
		return 0;

	mutex_lock(&priv->reg_lock);
	res = yt921x_vlan_filtering(priv, port, vlan_filtering);
	mutex_unlock(&priv->reg_lock);

	return res;
}

static int
yt921x_dsa_port_vlan_del(struct dsa_switch *ds, int port,
			 const struct switchdev_obj_port_vlan *vlan)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	u16 vid = vlan->vid;
	u16 pvid;
	int res;

	if (dsa_is_cpu_port(ds, port))
		return 0;

	mutex_lock(&priv->reg_lock);
	do {
		struct dsa_port *dp = dsa_to_port(ds, port);
		struct net_device *bdev;

		res = yt921x_vlan_del(priv, port, vid);
		if (res)
			break;

		bdev = dsa_port_bridge_dev_get(dp);
		if (bdev) {
			br_vlan_get_pvid(bdev, &pvid);
			if (pvid == vid)
				res = yt921x_pvid_clear(priv, port);
		}
	} while (0);
	mutex_unlock(&priv->reg_lock);

	return res;
}

static int
yt921x_dsa_port_vlan_add(struct dsa_switch *ds, int port,
			 const struct switchdev_obj_port_vlan *vlan,
			 struct netlink_ext_ack *extack)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	u16 vid = vlan->vid;
	u16 pvid;
	int res;

	/* CPU port is supposed to be a member of every VLAN; see
	 * yt921x_vlan_add() and yt921x_port_setup()
	 */
	if (dsa_is_cpu_port(ds, port))
		return 0;

	mutex_lock(&priv->reg_lock);
	do {
		struct dsa_port *dp = dsa_to_port(ds, port);
		struct net_device *bdev;

		res = yt921x_vlan_add(priv, port, vid,
				      vlan->flags & BRIDGE_VLAN_INFO_UNTAGGED);
		if (res)
			break;

		bdev = dsa_port_bridge_dev_get(dp);
		if (bdev) {
			if (vlan->flags & BRIDGE_VLAN_INFO_PVID) {
				res = yt921x_pvid_set(priv, port, vid);
			} else {
				br_vlan_get_pvid(bdev, &pvid);
				if (pvid == vid)
					res = yt921x_pvid_clear(priv, port);
			}
		}
	} while (0);
	mutex_unlock(&priv->reg_lock);

	return res;
}

static int yt921x_userport_standalone(struct yt921x_priv *priv, int port)
{
	u32 mask;
	u32 ctrl;
	int res;

	ctrl = ~priv->cpu_ports_mask;
	res = yt921x_reg_write(priv, YT921X_PORTn_ISOLATION(port), ctrl);
	if (res)
		return res;

	/* Turn off FDB learning to prevent FDB pollution */
	mask = YT921X_PORT_LEARN_DIS;
	res = yt921x_reg_set_bits(priv, YT921X_PORTn_LEARN(port), mask);
	if (res)
		return res;

	/* Turn off VLAN awareness */
	mask = YT921X_PORT_IGR_TPIDn_CTAG_M;
	res = yt921x_reg_clear_bits(priv, YT921X_PORTn_IGR_TPID(port), mask);
	if (res)
		return res;

	/* Unrelated since learning is off and all packets are trapped;
	 * set it anyway
	 */
	res = yt921x_port_set_pvid(priv, port, YT921X_VID_UNWARE);
	if (res)
		return res;

	return 0;
}

static int yt921x_userport_bridge(struct yt921x_priv *priv, int port)
{
	u32 mask;
	int res;

	mask = YT921X_PORT_LEARN_DIS;
	res = yt921x_reg_clear_bits(priv, YT921X_PORTn_LEARN(port), mask);
	if (res)
		return res;

	return 0;
}

static int yt921x_isolate(struct yt921x_priv *priv, int port)
{
	u32 mask;
	int res;

	mask = BIT(port);
	for (int i = 0; i < YT921X_PORT_NUM; i++) {
		if ((BIT(i) & priv->cpu_ports_mask) || i == port)
			continue;

		res = yt921x_reg_set_bits(priv, YT921X_PORTn_ISOLATION(i),
					  mask);
		if (res)
			return res;
	}

	return 0;
}

/* Make sure to include the CPU port in ports_mask, or your bridge will
 * not have it.
 */
static int yt921x_bridge(struct yt921x_priv *priv, u16 ports_mask)
{
	unsigned long targets_mask = ports_mask & ~priv->cpu_ports_mask;
	u32 isolated_mask;
	u32 ctrl;
	int port;
	int res;

	isolated_mask = 0;
	for_each_set_bit(port, &targets_mask, YT921X_PORT_NUM) {
		struct yt921x_port *pp = &priv->ports[port];

		if (pp->isolated)
			isolated_mask |= BIT(port);
	}

	/* Block from non-cpu bridge ports ... */
	for_each_set_bit(port, &targets_mask, YT921X_PORT_NUM) {
		struct yt921x_port *pp = &priv->ports[port];

		/* to non-bridge ports */
		ctrl = ~ports_mask;
		/* to isolated ports when isolated */
		if (pp->isolated)
			ctrl |= isolated_mask;
		/* to itself when non-hairpin */
		if (!pp->hairpin)
			ctrl |= BIT(port);
		else
			ctrl &= ~BIT(port);

		res = yt921x_reg_write(priv, YT921X_PORTn_ISOLATION(port),
				       ctrl);
		if (res)
			return res;
	}

	return 0;
}

static int yt921x_bridge_leave(struct yt921x_priv *priv, int port)
{
	int res;

	res = yt921x_userport_standalone(priv, port);
	if (res)
		return res;

	res = yt921x_isolate(priv, port);
	if (res)
		return res;

	return 0;
}

static int
yt921x_bridge_join(struct yt921x_priv *priv, int port, u16 ports_mask)
{
	int res;

	res = yt921x_userport_bridge(priv, port);
	if (res)
		return res;

	res = yt921x_bridge(priv, ports_mask);
	if (res)
		return res;

	return 0;
}

static u32
dsa_bridge_ports(struct dsa_switch *ds, const struct net_device *bdev)
{
	struct dsa_port *dp;
	u32 mask = 0;

	dsa_switch_for_each_user_port(dp, ds)
		if (dsa_port_offloads_bridge_dev(dp, bdev))
			mask |= BIT(dp->index);

	return mask;
}

static int
yt921x_bridge_flags(struct yt921x_priv *priv, int port,
		    struct switchdev_brport_flags flags)
{
	struct yt921x_port *pp = &priv->ports[port];
	bool do_flush;
	u32 mask;
	int res;

	if (flags.mask & BR_LEARNING) {
		bool learning = flags.val & BR_LEARNING;

		mask = YT921X_PORT_LEARN_DIS;
		res = yt921x_reg_toggle_bits(priv, YT921X_PORTn_LEARN(port),
					     mask, !learning);
		if (res)
			return res;
	}

	/* BR_FLOOD, BR_MCAST_FLOOD: see the comment where ACT_UNK_ACTn_TRAP
	 * is set
	 */

	/* BR_BCAST_FLOOD: we can filter bcast, but cannot trap them */

	do_flush = false;
	if (flags.mask & BR_HAIRPIN_MODE) {
		pp->hairpin = flags.val & BR_HAIRPIN_MODE;
		do_flush = true;
	}
	if (flags.mask & BR_ISOLATED) {
		pp->isolated = flags.val & BR_ISOLATED;
		do_flush = true;
	}
	if (do_flush) {
		struct dsa_switch *ds = &priv->ds;
		struct dsa_port *dp = dsa_to_port(ds, port);
		struct net_device *bdev;

		bdev = dsa_port_bridge_dev_get(dp);
		if (bdev) {
			u32 ports_mask;

			ports_mask = dsa_bridge_ports(ds, bdev);
			ports_mask |= priv->cpu_ports_mask;
			res = yt921x_bridge(priv, ports_mask);
			if (res)
				return res;
		}
	}

	return 0;
}

static int
yt921x_dsa_port_pre_bridge_flags(struct dsa_switch *ds, int port,
				 struct switchdev_brport_flags flags,
				 struct netlink_ext_ack *extack)
{
	if (flags.mask & ~(BR_HAIRPIN_MODE | BR_LEARNING | BR_FLOOD |
			   BR_MCAST_FLOOD | BR_ISOLATED))
		return -EINVAL;
	return 0;
}

static int
yt921x_dsa_port_bridge_flags(struct dsa_switch *ds, int port,
			     struct switchdev_brport_flags flags,
			     struct netlink_ext_ack *extack)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	int res;

	if (dsa_is_cpu_port(ds, port))
		return 0;

	mutex_lock(&priv->reg_lock);
	res = yt921x_bridge_flags(priv, port, flags);
	mutex_unlock(&priv->reg_lock);

	return res;
}

static void
yt921x_dsa_port_bridge_leave(struct dsa_switch *ds, int port,
			     struct dsa_bridge bridge)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	struct device *dev = to_device(priv);
	int res;

	if (dsa_is_cpu_port(ds, port))
		return;

	mutex_lock(&priv->reg_lock);
	res = yt921x_bridge_leave(priv, port);
	mutex_unlock(&priv->reg_lock);

	if (res)
		dev_err(dev, "Failed to %s port %d: %i\n", "unbridge",
			port, res);
}

static int
yt921x_dsa_port_bridge_join(struct dsa_switch *ds, int port,
			    struct dsa_bridge bridge, bool *tx_fwd_offload,
			    struct netlink_ext_ack *extack)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	u16 ports_mask;
	int res;

	if (dsa_is_cpu_port(ds, port))
		return 0;

	ports_mask = dsa_bridge_ports(ds, bridge.dev);
	ports_mask |= priv->cpu_ports_mask;

	mutex_lock(&priv->reg_lock);
	res = yt921x_bridge_join(priv, port, ports_mask);
	mutex_unlock(&priv->reg_lock);

	return res;
}

static int
yt921x_dsa_port_mst_state_set(struct dsa_switch *ds, int port,
			      const struct switchdev_mst_state *st)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	u32 mask;
	u32 ctrl;
	int res;

	mask = YT921X_STP_PORTn_M(port);
	switch (st->state) {
	case BR_STATE_DISABLED:
		ctrl = YT921X_STP_PORTn_DISABLED(port);
		break;
	case BR_STATE_LISTENING:
	case BR_STATE_LEARNING:
		ctrl = YT921X_STP_PORTn_LEARNING(port);
		break;
	case BR_STATE_FORWARDING:
	default:
		ctrl = YT921X_STP_PORTn_FORWARD(port);
		break;
	case BR_STATE_BLOCKING:
		ctrl = YT921X_STP_PORTn_BLOCKING(port);
		break;
	}

	mutex_lock(&priv->reg_lock);
	res = yt921x_reg_update_bits(priv, YT921X_STPn(st->msti), mask, ctrl);
	mutex_unlock(&priv->reg_lock);

	return res;
}

static int
yt921x_dsa_vlan_msti_set(struct dsa_switch *ds, struct dsa_bridge bridge,
			 const struct switchdev_vlan_msti *msti)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	u64 mask64;
	u64 ctrl64;
	int res;

	if (!msti->vid)
		return -EINVAL;
	if (!msti->msti || msti->msti >= YT921X_MSTI_NUM)
		return -EINVAL;

	mask64 = YT921X_VLAN_CTRL_STP_ID_M;
	ctrl64 = YT921X_VLAN_CTRL_STP_ID(msti->msti);

	mutex_lock(&priv->reg_lock);
	res = yt921x_reg64_update_bits(priv, YT921X_VLANn_CTRL(msti->vid),
				       mask64, ctrl64);
	mutex_unlock(&priv->reg_lock);

	return res;
}

static void
yt921x_dsa_port_stp_state_set(struct dsa_switch *ds, int port, u8 state)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	struct dsa_port *dp = dsa_to_port(ds, port);
	struct device *dev = to_device(priv);
	bool learning;
	u32 mask;
	u32 ctrl;
	int res;

	mask = YT921X_STP_PORTn_M(port);
	learning = false;
	switch (state) {
	case BR_STATE_DISABLED:
		ctrl = YT921X_STP_PORTn_DISABLED(port);
		break;
	case BR_STATE_LISTENING:
		ctrl = YT921X_STP_PORTn_LEARNING(port);
		break;
	case BR_STATE_LEARNING:
		ctrl = YT921X_STP_PORTn_LEARNING(port);
		learning = dp->learning;
		break;
	case BR_STATE_FORWARDING:
	default:
		ctrl = YT921X_STP_PORTn_FORWARD(port);
		learning = dp->learning;
		break;
	case BR_STATE_BLOCKING:
		ctrl = YT921X_STP_PORTn_BLOCKING(port);
		break;
	}

	mutex_lock(&priv->reg_lock);
	do {
		res = yt921x_reg_update_bits(priv, YT921X_STPn(0), mask, ctrl);
		if (res)
			break;

		mask = YT921X_PORT_LEARN_DIS;
		ctrl = !learning ? YT921X_PORT_LEARN_DIS : 0;
		res = yt921x_reg_update_bits(priv, YT921X_PORTn_LEARN(port),
					     mask, ctrl);
	} while (0);
	mutex_unlock(&priv->reg_lock);

	if (res)
		dev_err(dev, "Failed to %s port %d: %i\n", "set STP state for",
			port, res);
}

static int yt921x_port_down(struct yt921x_priv *priv, int port)
{
	u32 mask;
	int res;

	mask = YT921X_PORT_LINK | YT921X_PORT_RX_MAC_EN | YT921X_PORT_TX_MAC_EN;
	res = yt921x_reg_clear_bits(priv, YT921X_PORTn_CTRL(port), mask);
	if (res)
		return res;

	if (yt921x_port_is_external(port)) {
		mask = YT921X_SERDES_LINK;
		res = yt921x_reg_clear_bits(priv, YT921X_SERDESn(port), mask);
		if (res)
			return res;

		mask = YT921X_XMII_LINK;
		res = yt921x_reg_clear_bits(priv, YT921X_XMIIn(port), mask);
		if (res)
			return res;
	}

	return 0;
}

static int
yt921x_port_up(struct yt921x_priv *priv, int port, unsigned int mode,
	       phy_interface_t interface, int speed, int duplex,
	       bool tx_pause, bool rx_pause)
{
	u32 mask;
	u32 ctrl;
	int res;

	switch (speed) {
	case SPEED_10:
		ctrl = YT921X_PORT_SPEED_10;
		break;
	case SPEED_100:
		ctrl = YT921X_PORT_SPEED_100;
		break;
	case SPEED_1000:
		ctrl = YT921X_PORT_SPEED_1000;
		break;
	case SPEED_2500:
		ctrl = YT921X_PORT_SPEED_2500;
		break;
	case SPEED_10000:
		ctrl = YT921X_PORT_SPEED_10000;
		break;
	default:
		return -EINVAL;
	}
	if (duplex == DUPLEX_FULL)
		ctrl |= YT921X_PORT_DUPLEX_FULL;
	if (tx_pause)
		ctrl |= YT921X_PORT_TX_PAUSE;
	if (rx_pause)
		ctrl |= YT921X_PORT_RX_PAUSE;
	ctrl |= YT921X_PORT_RX_MAC_EN | YT921X_PORT_TX_MAC_EN;
	res = yt921x_reg_write(priv, YT921X_PORTn_CTRL(port), ctrl);
	if (res)
		return res;

	if (yt921x_port_is_external(port)) {
		mask = YT921X_SERDES_SPEED_M;
		switch (speed) {
		case SPEED_10:
			ctrl = YT921X_SERDES_SPEED_10;
			break;
		case SPEED_100:
			ctrl = YT921X_SERDES_SPEED_100;
			break;
		case SPEED_1000:
			ctrl = YT921X_SERDES_SPEED_1000;
			break;
		case SPEED_2500:
			ctrl = YT921X_SERDES_SPEED_2500;
			break;
		case SPEED_10000:
			ctrl = YT921X_SERDES_SPEED_10000;
			break;
		default:
			return -EINVAL;
		}
		mask |= YT921X_SERDES_DUPLEX_FULL;
		if (duplex == DUPLEX_FULL)
			ctrl |= YT921X_SERDES_DUPLEX_FULL;
		mask |= YT921X_SERDES_TX_PAUSE;
		if (tx_pause)
			ctrl |= YT921X_SERDES_TX_PAUSE;
		mask |= YT921X_SERDES_RX_PAUSE;
		if (rx_pause)
			ctrl |= YT921X_SERDES_RX_PAUSE;
		mask |= YT921X_SERDES_LINK;
		ctrl |= YT921X_SERDES_LINK;
		res = yt921x_reg_update_bits(priv, YT921X_SERDESn(port),
					     mask, ctrl);
		if (res)
			return res;

		mask = YT921X_XMII_LINK;
		res = yt921x_reg_set_bits(priv, YT921X_XMIIn(port), mask);
		if (res)
			return res;

		switch (speed) {
		case SPEED_10:
			ctrl = YT921X_MDIO_POLLING_SPEED_10;
			break;
		case SPEED_100:
			ctrl = YT921X_MDIO_POLLING_SPEED_100;
			break;
		case SPEED_1000:
			ctrl = YT921X_MDIO_POLLING_SPEED_1000;
			break;
		case SPEED_2500:
			ctrl = YT921X_MDIO_POLLING_SPEED_2500;
			break;
		case SPEED_10000:
			ctrl = YT921X_MDIO_POLLING_SPEED_10000;
			break;
		default:
			return -EINVAL;
		}
		if (duplex == DUPLEX_FULL)
			ctrl |= YT921X_MDIO_POLLING_DUPLEX_FULL;
		ctrl |= YT921X_MDIO_POLLING_LINK;
		res = yt921x_reg_write(priv, YT921X_MDIO_POLLINGn(port), ctrl);
		if (res)
			return res;
	}

	return 0;
}

static int
yt921x_port_config(struct yt921x_priv *priv, int port, unsigned int mode,
		   phy_interface_t interface)
{
	struct device *dev = to_device(priv);
	u32 mask;
	u32 ctrl;
	int res;

	if (!yt921x_port_is_external(port)) {
		if (interface != PHY_INTERFACE_MODE_INTERNAL) {
			dev_err(dev, "Wrong mode %d on port %d\n",
				interface, port);
			return -EINVAL;
		}
		return 0;
	}

	switch (interface) {
	/* SERDES */
	case PHY_INTERFACE_MODE_SGMII:
	case PHY_INTERFACE_MODE_100BASEX:
	case PHY_INTERFACE_MODE_1000BASEX:
	case PHY_INTERFACE_MODE_2500BASEX:
		mask = YT921X_SERDES_CTRL_PORTn(port);
		res = yt921x_reg_set_bits(priv, YT921X_SERDES_CTRL, mask);
		if (res)
			return res;

		mask = YT921X_XMII_CTRL_PORTn(port);
		res = yt921x_reg_clear_bits(priv, YT921X_XMII_CTRL, mask);
		if (res)
			return res;

		mask = YT921X_SERDES_MODE_M;
		switch (interface) {
		case PHY_INTERFACE_MODE_SGMII:
			ctrl = YT921X_SERDES_MODE_SGMII;
			break;
		case PHY_INTERFACE_MODE_100BASEX:
			ctrl = YT921X_SERDES_MODE_100BASEX;
			break;
		case PHY_INTERFACE_MODE_1000BASEX:
			ctrl = YT921X_SERDES_MODE_1000BASEX;
			break;
		case PHY_INTERFACE_MODE_2500BASEX:
			ctrl = YT921X_SERDES_MODE_2500BASEX;
			break;
		default:
			return -EINVAL;
		}
		res = yt921x_reg_update_bits(priv, YT921X_SERDESn(port),
					     mask, ctrl);
		if (res)
			return res;

		break;
	/* add XMII support here */
	default:
		return -EINVAL;
	}

	return 0;
}

static void
yt921x_phylink_mac_link_down(struct phylink_config *config, unsigned int mode,
			     phy_interface_t interface)
{
	struct dsa_port *dp = dsa_phylink_to_port(config);
	struct yt921x_priv *priv = to_yt921x_priv(dp->ds);
	int port = dp->index;
	int res;

	/* No need to sync; port control block is hold until device remove */
	cancel_delayed_work(&priv->ports[port].mib_read);

	mutex_lock(&priv->reg_lock);
	res = yt921x_port_down(priv, port);
	mutex_unlock(&priv->reg_lock);

	if (res)
		dev_err(dp->ds->dev, "Failed to %s port %d: %i\n", "bring down",
			port, res);
}

static void
yt921x_phylink_mac_link_up(struct phylink_config *config,
			   struct phy_device *phydev, unsigned int mode,
			   phy_interface_t interface, int speed, int duplex,
			   bool tx_pause, bool rx_pause)
{
	struct dsa_port *dp = dsa_phylink_to_port(config);
	struct yt921x_priv *priv = to_yt921x_priv(dp->ds);
	int port = dp->index;
	int res;

	mutex_lock(&priv->reg_lock);
	res = yt921x_port_up(priv, port, mode, interface, speed, duplex,
			     tx_pause, rx_pause);
	mutex_unlock(&priv->reg_lock);

	if (res)
		dev_err(dp->ds->dev, "Failed to %s port %d: %i\n", "bring up",
			port, res);

	schedule_delayed_work(&priv->ports[port].mib_read, 0);
}

static void
yt921x_phylink_mac_config(struct phylink_config *config, unsigned int mode,
			  const struct phylink_link_state *state)
{
	struct dsa_port *dp = dsa_phylink_to_port(config);
	struct yt921x_priv *priv = to_yt921x_priv(dp->ds);
	int port = dp->index;
	int res;

	mutex_lock(&priv->reg_lock);
	res = yt921x_port_config(priv, port, mode, state->interface);
	mutex_unlock(&priv->reg_lock);

	if (res)
		dev_err(dp->ds->dev, "Failed to %s port %d: %i\n", "config",
			port, res);
}

static void
yt921x_dsa_phylink_get_caps(struct dsa_switch *ds, int port,
			    struct phylink_config *config)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	const struct yt921x_info *info = priv->info;

	config->mac_capabilities = MAC_ASYM_PAUSE | MAC_SYM_PAUSE |
				   MAC_10 | MAC_100 | MAC_1000;

	if (info->internal_mask & BIT(port)) {
		/* Port 10 for MCU should probably go here too. But since that
		 * is untested yet, turn it down for the moment by letting it
		 * fall to the default branch.
		 */
		__set_bit(PHY_INTERFACE_MODE_INTERNAL,
			  config->supported_interfaces);
	} else if (info->external_mask & BIT(port)) {
		/* TODO: external ports may support SERDES only, XMII only, or
		 * SERDES + XMII depending on the chip. However, we can't get
		 * the accurate config table due to lack of document, thus
		 * we simply declare SERDES + XMII and rely on the correctness
		 * of devicetree for now.
		 */

		/* SERDES */
		__set_bit(PHY_INTERFACE_MODE_SGMII,
			  config->supported_interfaces);
		/* REVSGMII (SGMII in PHY role) should go here, once
		 * PHY_INTERFACE_MODE_REVSGMII is introduced.
		 */
		__set_bit(PHY_INTERFACE_MODE_100BASEX,
			  config->supported_interfaces);
		__set_bit(PHY_INTERFACE_MODE_1000BASEX,
			  config->supported_interfaces);
		__set_bit(PHY_INTERFACE_MODE_2500BASEX,
			  config->supported_interfaces);
		config->mac_capabilities |= MAC_2500FD;

		/* XMII */

		/* Not tested. To add support for XMII:
		 *   - Add proper interface modes below
		 *   - Handle them in yt921x_port_config()
		 */
	}
	/* no such port: empty supported_interfaces causes phylink to turn it
	 * down
	 */
}

static int yt921x_port_setup(struct yt921x_priv *priv, int port)
{
	struct dsa_switch *ds = &priv->ds;
	u32 ctrl;
	int res;

	res = yt921x_userport_standalone(priv, port);
	if (res)
		return res;

	if (dsa_is_cpu_port(ds, port)) {
		/* Egress of CPU port is supposed to be completely controlled
		 * via tagging, so set to oneway isolated (drop all packets
		 * without tag).
		 */
		ctrl = ~(u32)0;
		res = yt921x_reg_write(priv, YT921X_PORTn_ISOLATION(port),
				       ctrl);
		if (res)
			return res;

		/* To simplify FDB "isolation" simulation, we also disable
		 * learning on the CPU port, and let software identify packets
		 * towarding CPU (either trapped or a static FDB entry is
		 * matched, no matter which bridge that entry is for), which is
		 * already done by yt921x_userport_standalone(). As a result,
		 * VLAN-awareness becomes unrelated on the CPU port (set to
		 * VLAN-unaware by the way).
		 */
	}

	return 0;
}

static enum dsa_tag_protocol
yt921x_dsa_get_tag_protocol(struct dsa_switch *ds, int port,
			    enum dsa_tag_protocol m)
{
	return DSA_TAG_PROTO_YT921X;
}

static int yt921x_dsa_port_setup(struct dsa_switch *ds, int port)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	int res;

	mutex_lock(&priv->reg_lock);
	res = yt921x_port_setup(priv, port);
	mutex_unlock(&priv->reg_lock);

	return res;
}

static int yt921x_edata_wait(struct yt921x_priv *priv, u32 *valp)
{
	u32 val = YT921X_EDATA_DATA_IDLE;
	int res;

	res = yt921x_reg_wait(priv, YT921X_EDATA_DATA,
			      YT921X_EDATA_DATA_STATUS_M, &val);
	if (res)
		return res;

	*valp = val;
	return 0;
}

static int
yt921x_edata_read_cont(struct yt921x_priv *priv, u8 addr, u8 *valp)
{
	u32 ctrl;
	u32 val;
	int res;

	ctrl = YT921X_EDATA_CTRL_ADDR(addr) | YT921X_EDATA_CTRL_READ;
	res = yt921x_reg_write(priv, YT921X_EDATA_CTRL, ctrl);
	if (res)
		return res;
	res = yt921x_edata_wait(priv, &val);
	if (res)
		return res;

	*valp = FIELD_GET(YT921X_EDATA_DATA_DATA_M, val);
	return 0;
}

static int yt921x_edata_read(struct yt921x_priv *priv, u8 addr, u8 *valp)
{
	u32 val;
	int res;

	res = yt921x_edata_wait(priv, &val);
	if (res)
		return res;
	return yt921x_edata_read_cont(priv, addr, valp);
}

static int yt921x_chip_detect(struct yt921x_priv *priv)
{
	struct device *dev = to_device(priv);
	const struct yt921x_info *info;
	u8 extmode;
	u32 chipid;
	u32 major;
	u32 mode;
	int res;

	res = yt921x_reg_read(priv, YT921X_CHIP_ID, &chipid);
	if (res)
		return res;

	major = FIELD_GET(YT921X_CHIP_ID_MAJOR, chipid);

	for (info = yt921x_infos; info->name; info++)
		if (info->major == major)
			break;
	if (!info->name) {
		dev_err(dev, "Unexpected chipid 0x%x\n", chipid);
		return -ENODEV;
	}

	res = yt921x_reg_read(priv, YT921X_CHIP_MODE, &mode);
	if (res)
		return res;
	res = yt921x_edata_read(priv, YT921X_EDATA_EXTMODE, &extmode);
	if (res)
		return res;

	for (; info->name; info++)
		if (info->major == major && info->mode == mode &&
		    info->extmode == extmode)
			break;
	if (!info->name) {
		dev_err(dev,
			"Unsupported chipid 0x%x with chipmode 0x%x 0x%x\n",
			chipid, mode, extmode);
		return -ENODEV;
	}

	/* Print chipid here since we are interested in lower 16 bits */
	dev_info(dev,
		 "Motorcomm %s ethernet switch, chipid: 0x%x, chipmode: 0x%x 0x%x\n",
		 info->name, chipid, mode, extmode);

	priv->info = info;
	return 0;
}

static int yt921x_chip_reset(struct yt921x_priv *priv)
{
	struct device *dev = to_device(priv);
	u16 eth_p_tag;
	u32 val;
	int res;

	res = yt921x_chip_detect(priv);
	if (res)
		return res;

	/* Reset */
	res = yt921x_reg_write(priv, YT921X_RST, YT921X_RST_HW);
	if (res)
		return res;

	/* RST_HW is almost same as GPIO hard reset, so we need this delay. */
	fsleep(YT921X_RST_DELAY_US);

	val = 0;
	res = yt921x_reg_wait(priv, YT921X_RST, ~0, &val);
	if (res)
		return res;

	/* Check for tag EtherType; do it after reset in case you messed it up
	 * before.
	 */
	res = yt921x_reg_read(priv, YT921X_CPU_TAG_TPID, &val);
	if (res)
		return res;
	eth_p_tag = FIELD_GET(YT921X_CPU_TAG_TPID_TPID_M, val);
	if (eth_p_tag != ETH_P_YT921X) {
		dev_err(dev, "Tag type 0x%x != 0x%x\n", eth_p_tag,
			ETH_P_YT921X);
		/* Despite being possible, we choose not to set CPU_TAG_TPID,
		 * since there is no way it can be different unless you have the
		 * wrong chip.
		 */
		return -EINVAL;
	}

	return 0;
}

static int yt921x_chip_setup(struct yt921x_priv *priv)
{
	struct dsa_switch *ds = &priv->ds;
	unsigned long cpu_ports_mask;
	u64 ctrl64;
	u32 ctrl;
	int port;
	int res;

	/* Enable DSA */
	priv->cpu_ports_mask = dsa_cpu_ports(ds);

	ctrl = YT921X_EXT_CPU_PORT_TAG_EN | YT921X_EXT_CPU_PORT_PORT_EN |
	       YT921X_EXT_CPU_PORT_PORT(__ffs(priv->cpu_ports_mask));
	res = yt921x_reg_write(priv, YT921X_EXT_CPU_PORT, ctrl);
	if (res)
		return res;

	/* Enable and clear MIB */
	res = yt921x_reg_set_bits(priv, YT921X_FUNC, YT921X_FUNC_MIB);
	if (res)
		return res;

	ctrl = YT921X_MIB_CTRL_CLEAN | YT921X_MIB_CTRL_ALL_PORT;
	res = yt921x_reg_write(priv, YT921X_MIB_CTRL, ctrl);
	if (res)
		return res;

	/* Setup software switch */
	ctrl = YT921X_CPU_COPY_TO_EXT_CPU;
	res = yt921x_reg_write(priv, YT921X_CPU_COPY, ctrl);
	if (res)
		return res;

	ctrl = GENMASK(10, 0);
	res = yt921x_reg_write(priv, YT921X_FILTER_UNK_UCAST, ctrl);
	if (res)
		return res;
	res = yt921x_reg_write(priv, YT921X_FILTER_UNK_MCAST, ctrl);
	if (res)
		return res;

	/* YT921x does not support native DSA port bridging, so we use port
	 * isolation to emulate it. However, be especially careful that port
	 * isolation takes _after_ FDB lookups, i.e. if an FDB entry (from
	 * another bridge) is matched and the destination port (in another
	 * bridge) is blocked, the packet will be dropped instead of flooding to
	 * the "bridged" ports, thus we need to trap and handle those packets by
	 * software.
	 *
	 * If there is no more than one bridge, we might be able to drop them
	 * directly given some conditions are met, but we trap them in all cases
	 * for now.
	 */
	ctrl = 0;
	for (int i = 0; i < YT921X_PORT_NUM; i++)
		ctrl |= YT921X_ACT_UNK_ACTn_TRAP(i);
	/* Except for CPU ports, if any packets are sent via CPU ports without
	 * tag, they should be dropped.
	 */
	cpu_ports_mask = priv->cpu_ports_mask;
	for_each_set_bit(port, &cpu_ports_mask, YT921X_PORT_NUM) {
		ctrl &= ~YT921X_ACT_UNK_ACTn_M(port);
		ctrl |= YT921X_ACT_UNK_ACTn_DROP(port);
	}
	res = yt921x_reg_write(priv, YT921X_ACT_UNK_UCAST, ctrl);
	if (res)
		return res;
	res = yt921x_reg_write(priv, YT921X_ACT_UNK_MCAST, ctrl);
	if (res)
		return res;

	/* Tagged VID 0 should be treated as untagged, which confuses the
	 * hardware a lot
	 */
	ctrl64 = YT921X_VLAN_CTRL_LEARN_DIS | YT921X_VLAN_CTRL_PORTS_M;
	res = yt921x_reg64_write(priv, YT921X_VLANn_CTRL(0), ctrl64);
	if (res)
		return res;

	/* Miscellaneous */
	res = yt921x_reg_set_bits(priv, YT921X_SENSOR, YT921X_SENSOR_TEMP);
	if (res)
		return res;

	return 0;
}

static int yt921x_dsa_setup(struct dsa_switch *ds)
{
	struct yt921x_priv *priv = to_yt921x_priv(ds);
	struct device *dev = to_device(priv);
	struct device_node *np = dev->of_node;
	struct device_node *child;
	int res;

	mutex_lock(&priv->reg_lock);
	res = yt921x_chip_reset(priv);
	mutex_unlock(&priv->reg_lock);

	if (res)
		return res;

	/* Register the internal mdio bus. Nodes for internal ports should have
	 * proper phy-handle pointing to their PHYs. Not enabling the internal
	 * bus is possible, though pretty wired, if internal ports are not used.
	 */
	child = of_get_child_by_name(np, "mdio");
	if (child) {
		res = yt921x_mbus_int_init(priv, child);
		of_node_put(child);
		if (res)
			return res;
	}

	/* External mdio bus is optional */
	child = of_get_child_by_name(np, "mdio-external");
	if (child) {
		res = yt921x_mbus_ext_init(priv, child);
		of_node_put(child);
		if (res)
			return res;

		dev_err(dev, "Untested external mdio bus\n");
		return -ENODEV;
	}

	mutex_lock(&priv->reg_lock);
	res = yt921x_chip_setup(priv);
	mutex_unlock(&priv->reg_lock);

	if (res)
		return res;

	return 0;
}

static const struct phylink_mac_ops yt921x_phylink_mac_ops = {
	.mac_link_down	= yt921x_phylink_mac_link_down,
	.mac_link_up	= yt921x_phylink_mac_link_up,
	.mac_config	= yt921x_phylink_mac_config,
};

static const struct dsa_switch_ops yt921x_dsa_switch_ops = {
	/* mib */
	.get_strings		= yt921x_dsa_get_strings,
	.get_ethtool_stats	= yt921x_dsa_get_ethtool_stats,
	.get_sset_count		= yt921x_dsa_get_sset_count,
	.get_eth_mac_stats	= yt921x_dsa_get_eth_mac_stats,
	.get_eth_ctrl_stats	= yt921x_dsa_get_eth_ctrl_stats,
	.get_rmon_stats		= yt921x_dsa_get_rmon_stats,
	.get_stats64		= yt921x_dsa_get_stats64,
	.get_pause_stats	= yt921x_dsa_get_pause_stats,
	/* eee */
	.support_eee		= dsa_supports_eee,
	.set_mac_eee		= yt921x_dsa_set_mac_eee,
	/* mtu */
	.port_change_mtu	= yt921x_dsa_port_change_mtu,
	.port_max_mtu		= yt921x_dsa_port_max_mtu,
	/* hsr */
	.port_hsr_leave		= dsa_port_simple_hsr_leave,
	.port_hsr_join		= dsa_port_simple_hsr_join,
	/* mirror */
	.port_mirror_del	= yt921x_dsa_port_mirror_del,
	.port_mirror_add	= yt921x_dsa_port_mirror_add,
	/* fdb */
	.port_fdb_dump		= yt921x_dsa_port_fdb_dump,
	.port_fast_age		= yt921x_dsa_port_fast_age,
	.set_ageing_time	= yt921x_dsa_set_ageing_time,
	.port_fdb_del		= yt921x_dsa_port_fdb_del,
	.port_fdb_add		= yt921x_dsa_port_fdb_add,
	.port_mdb_del		= yt921x_dsa_port_mdb_del,
	.port_mdb_add		= yt921x_dsa_port_mdb_add,
	/* vlan */
	.port_vlan_filtering	= yt921x_dsa_port_vlan_filtering,
	.port_vlan_del		= yt921x_dsa_port_vlan_del,
	.port_vlan_add		= yt921x_dsa_port_vlan_add,
	/* bridge */
	.port_pre_bridge_flags	= yt921x_dsa_port_pre_bridge_flags,
	.port_bridge_flags	= yt921x_dsa_port_bridge_flags,
	.port_bridge_leave	= yt921x_dsa_port_bridge_leave,
	.port_bridge_join	= yt921x_dsa_port_bridge_join,
	/* mst */
	.port_mst_state_set	= yt921x_dsa_port_mst_state_set,
	.vlan_msti_set		= yt921x_dsa_vlan_msti_set,
	.port_stp_state_set	= yt921x_dsa_port_stp_state_set,
	/* port */
	.get_tag_protocol	= yt921x_dsa_get_tag_protocol,
	.phylink_get_caps	= yt921x_dsa_phylink_get_caps,
	.port_setup		= yt921x_dsa_port_setup,
	/* chip */
	.setup			= yt921x_dsa_setup,
};

static void yt921x_mdio_shutdown(struct mdio_device *mdiodev)
{
	struct yt921x_priv *priv = mdiodev_get_drvdata(mdiodev);

	if (!priv)
		return;

	dsa_switch_shutdown(&priv->ds);
}

static void yt921x_mdio_remove(struct mdio_device *mdiodev)
{
	struct yt921x_priv *priv = mdiodev_get_drvdata(mdiodev);

	if (!priv)
		return;

	for (size_t i = ARRAY_SIZE(priv->ports); i-- > 0; ) {
		struct yt921x_port *pp = &priv->ports[i];

		disable_delayed_work_sync(&pp->mib_read);
	}

	dsa_unregister_switch(&priv->ds);

	mutex_destroy(&priv->reg_lock);
}

static int yt921x_mdio_probe(struct mdio_device *mdiodev)
{
	struct device *dev = &mdiodev->dev;
	struct yt921x_reg_mdio *mdio;
	struct yt921x_priv *priv;
	struct dsa_switch *ds;

	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	mdio = devm_kzalloc(dev, sizeof(*mdio), GFP_KERNEL);
	if (!mdio)
		return -ENOMEM;

	mdio->bus = mdiodev->bus;
	mdio->addr = mdiodev->addr;
	mdio->switchid = 0;

	mutex_init(&priv->reg_lock);

	priv->reg_ops = &yt921x_reg_ops_mdio;
	priv->reg_ctx = mdio;

	for (size_t i = 0; i < ARRAY_SIZE(priv->ports); i++) {
		struct yt921x_port *pp = &priv->ports[i];

		pp->index = i;
		INIT_DELAYED_WORK(&pp->mib_read, yt921x_poll_mib);
	}

	ds = &priv->ds;
	ds->dev = dev;
	ds->assisted_learning_on_cpu_port = true;
	ds->priv = priv;
	ds->ops = &yt921x_dsa_switch_ops;
	ds->ageing_time_min = 1 * 5000;
	ds->ageing_time_max = U16_MAX * 5000;
	ds->phylink_mac_ops = &yt921x_phylink_mac_ops;
	ds->num_ports = YT921X_PORT_NUM;

	mdiodev_set_drvdata(mdiodev, priv);

	return dsa_register_switch(ds);
}

static const struct of_device_id yt921x_of_match[] = {
	{ .compatible = "motorcomm,yt9215" },
	{}
};
MODULE_DEVICE_TABLE(of, yt921x_of_match);

static struct mdio_driver yt921x_mdio_driver = {
	.probe = yt921x_mdio_probe,
	.remove = yt921x_mdio_remove,
	.shutdown = yt921x_mdio_shutdown,
	.mdiodrv.driver = {
		.name = YT921X_NAME,
		.of_match_table = yt921x_of_match,
	},
};

mdio_module_driver(yt921x_mdio_driver);

MODULE_AUTHOR("David Yang <mmyangfl@gmail.com>");
MODULE_DESCRIPTION("Driver for Motorcomm YT921x Switch");
MODULE_LICENSE("GPL");