net: dsa: realtek-smi: Add Realtek SMI driver

This adds a driver core for the Realtek SMI chips and a
subdriver for the RTL8366RB. I just added this chip simply
because it is all I can test.

The code is a massaged variant of the code that has been
sitting out-of-tree in OpenWRT for years in the absence of
a proper switch subsystem. This creates a DSA driver for it.
I have tried to credit the original authors wherever
possible.

The main changes I've done from the OpenWRT code:

- Added an IRQ chip inside the RTL8366RB switch to demux and
  handle the line state IRQs.

- Distributed the phy handling out to the PHY driver.

- Added some RTL8366RB code that was missing in the driver at
  the time, such as setting up "green ethernet" with a funny
  jam table and forcing MAC5 (the CPU port) into 1 GBit.

- Select jam table and add the default jam table from the
  vendor driver, also for ASIC "version 0" if need be.

- Do not store jam tables in the device tree, store them
  in the driver.

- Pick in the "initvals" jam tables from OpenWRT's driver
  and make those get selected per compatible for the
  whole system. It's apparently about electrical settings
  for this system and whatnot, not really configuration
  from device tree.

- Implemented LED control: beware of bugs because there are
  no LEDs on the device I am using!

We do not implement custom DSA tags. This is explained in
a comment in the driver as well: this "tagging protocol" is
not simply a few extra bytes tagged on to the ethernet
frame as DSA is used to. Instead, enabling the CPU tags
will make the switch start talking Realtek RRCP internally.
For example a simple ping will make this kind of packets
appear inside the switch:

0000   ff ff ff ff ff ff bc ae c5 6b a8 3d 88 99 a2 00
0010   08 06 00 01 08 00 06 04 00 01 bc ae c5 6b a8 3d
0020   a9 fe 01 01 00 00 00 00 00 00 a9 fe 01 02 00 00
0030   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

As you can see a custom "8899" tagged packet using the
protocol 0xa2. Norm RRCP appears to always have this
protocol set to 0x01 according to OpenRRCP. You can also
see that this is not a ping packet at all, instead the
switch is starting to talk network management issues
with the CPU port.

So for now custom "tagging" is disabled.

This was tested on the D-Link DIR-685 with initramfs and
OpenWRT userspaces and works fine on all the LAN ports
(lan0 .. lan3). The WAN port is yet not working.

Cc: Antti Seppälä <a.seppala@gmail.com>
Cc: Roman Yeryomin <roman@advem.lv>
Cc: Colin Leitner <colin.leitner@googlemail.com>
Cc: Gabor Juhos <juhosg@openwrt.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

MAINTAINERS

@@ -12063,6 +12063,13 @@ S:	Maintained
 F:	sound/soc/codecs/rt*
 F:	include/sound/rt*.h
 
+REALTEK RTL83xx SMI DSA ROUTER CHIPS
+M:	Linus Walleij <linus.walleij@linaro.org>
+S:	Maintained
+F:	Documentation/devicetree/bindings/net/dsa/realtek-smi.txt
+F:	drivers/net/dsa/realtek-smi*
+F:	drivers/net/dsa/rtl83*
+
 REGISTER MAP ABSTRACTION
 M:	Mark Brown <broonie@kernel.org>
 L:	linux-kernel@vger.kernel.org

drivers/net/dsa/Kconfig

@@ -52,6 +52,17 @@ config NET_DSA_QCA8K
 	  This enables support for the Qualcomm Atheros QCA8K Ethernet
 	  switch chips.
 
+config NET_DSA_REALTEK_SMI
+	tristate "Realtek SMI Ethernet switch family support"
+	depends on NET_DSA
+	select FIXED_PHY
+	select IRQ_DOMAIN
+	select REALTEK_PHY
+	select REGMAP
+	---help---
+	  This enables support for the Realtek SMI-based switch
+	  chips, currently only RTL8366RB.
+
 config NET_DSA_SMSC_LAN9303
 	tristate
 	select NET_DSA_TAG_LAN9303

drivers/net/dsa/Makefile

@@ -8,6 +8,8 @@ endif
 obj-$(CONFIG_NET_DSA_MT7530)	+= mt7530.o
 obj-$(CONFIG_NET_DSA_MV88E6060) += mv88e6060.o
 obj-$(CONFIG_NET_DSA_QCA8K)	+= qca8k.o
+obj-$(CONFIG_NET_DSA_REALTEK_SMI) += realtek.o
+realtek-objs			:= realtek-smi.o rtl8366.o rtl8366rb.o
 obj-$(CONFIG_NET_DSA_SMSC_LAN9303) += lan9303-core.o
 obj-$(CONFIG_NET_DSA_SMSC_LAN9303_I2C) += lan9303_i2c.o
 obj-$(CONFIG_NET_DSA_SMSC_LAN9303_MDIO) += lan9303_mdio.o

drivers/net/dsa/realtek-smi.c

+// SPDX-License-Identifier: GPL-2.0+
+/* Realtek Simple Management Interface (SMI) driver
+ * It can be discussed how "simple" this interface is.
+ *
+ * The SMI protocol piggy-backs the MDIO MDC and MDIO signals levels
+ * but the protocol is not MDIO at all. Instead it is a Realtek
+ * pecularity that need to bit-bang the lines in a special way to
+ * communicate with the switch.
+ *
+ * ASICs we intend to support with this driver:
+ *
+ * RTL8366   - The original version, apparently
+ * RTL8369   - Similar enough to have the same datsheet as RTL8366
+ * RTL8366RB - Probably reads out "RTL8366 revision B", has a quite
+ *             different register layout from the other two
+ * RTL8366S  - Is this "RTL8366 super"?
+ * RTL8367   - Has an OpenWRT driver as well
+ * RTL8368S  - Seems to be an alternative name for RTL8366RB
+ * RTL8370   - Also uses SMI
+ *
+ * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
+ * Copyright (C) 2010 Antti Seppälä <a.seppala@gmail.com>
+ * Copyright (C) 2010 Roman Yeryomin <roman@advem.lv>
+ * Copyright (C) 2011 Colin Leitner <colin.leitner@googlemail.com>
+ * Copyright (C) 2009-2010 Gabor Juhos <juhosg@openwrt.org>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/spinlock.h>
+#include <linux/skbuff.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_mdio.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/bitops.h>
+#include <linux/if_bridge.h>
+
+#include "realtek-smi.h"
+
+#define REALTEK_SMI_ACK_RETRY_COUNT		5
+#define REALTEK_SMI_HW_STOP_DELAY		25	/* msecs */
+#define REALTEK_SMI_HW_START_DELAY		100	/* msecs */
+
+static inline void realtek_smi_clk_delay(struct realtek_smi *smi)
+{
+	ndelay(smi->clk_delay);
+}
+
+static void realtek_smi_start(struct realtek_smi *smi)
+{
+	/* Set GPIO pins to output mode, with initial state:
+	 * SCK = 0, SDA = 1
+	 */
+	gpiod_direction_output(smi->mdc, 0);
+	gpiod_direction_output(smi->mdio, 1);
+	realtek_smi_clk_delay(smi);
+
+	/* CLK 1: 0 -> 1, 1 -> 0 */
+	gpiod_set_value(smi->mdc, 1);
+	realtek_smi_clk_delay(smi);
+	gpiod_set_value(smi->mdc, 0);
+	realtek_smi_clk_delay(smi);
+
+	/* CLK 2: */
+	gpiod_set_value(smi->mdc, 1);
+	realtek_smi_clk_delay(smi);
+	gpiod_set_value(smi->mdio, 0);
+	realtek_smi_clk_delay(smi);
+	gpiod_set_value(smi->mdc, 0);
+	realtek_smi_clk_delay(smi);
+	gpiod_set_value(smi->mdio, 1);
+}
+
+static void realtek_smi_stop(struct realtek_smi *smi)
+{
+	realtek_smi_clk_delay(smi);
+	gpiod_set_value(smi->mdio, 0);
+	gpiod_set_value(smi->mdc, 1);
+	realtek_smi_clk_delay(smi);
+	gpiod_set_value(smi->mdio, 1);
+	realtek_smi_clk_delay(smi);
+	gpiod_set_value(smi->mdc, 1);
+	realtek_smi_clk_delay(smi);
+	gpiod_set_value(smi->mdc, 0);
+	realtek_smi_clk_delay(smi);
+	gpiod_set_value(smi->mdc, 1);
+
+	/* Add a click */
+	realtek_smi_clk_delay(smi);
+	gpiod_set_value(smi->mdc, 0);
+	realtek_smi_clk_delay(smi);
+	gpiod_set_value(smi->mdc, 1);
+
+	/* Set GPIO pins to input mode */
+	gpiod_direction_input(smi->mdio);
+	gpiod_direction_input(smi->mdc);
+}
+
+static void realtek_smi_write_bits(struct realtek_smi *smi, u32 data, u32 len)
+{
+	for (; len > 0; len--) {
+		realtek_smi_clk_delay(smi);
+
+		/* Prepare data */
+		gpiod_set_value(smi->mdio, !!(data & (1 << (len - 1))));
+		realtek_smi_clk_delay(smi);
+
+		/* Clocking */
+		gpiod_set_value(smi->mdc, 1);
+		realtek_smi_clk_delay(smi);
+		gpiod_set_value(smi->mdc, 0);
+	}
+}
+
+static void realtek_smi_read_bits(struct realtek_smi *smi, u32 len, u32 *data)
+{
+	gpiod_direction_input(smi->mdio);
+
+	for (*data = 0; len > 0; len--) {
+		u32 u;
+
+		realtek_smi_clk_delay(smi);
+
+		/* Clocking */
+		gpiod_set_value(smi->mdc, 1);
+		realtek_smi_clk_delay(smi);
+		u = !!gpiod_get_value(smi->mdio);
+		gpiod_set_value(smi->mdc, 0);
+
+		*data |= (u << (len - 1));
+	}
+
+	gpiod_direction_output(smi->mdio, 0);
+}
+
+static int realtek_smi_wait_for_ack(struct realtek_smi *smi)
+{
+	int retry_cnt;
+
+	retry_cnt = 0;
+	do {
+		u32 ack;
+
+		realtek_smi_read_bits(smi, 1, &ack);
+		if (ack == 0)
+			break;
+
+		if (++retry_cnt > REALTEK_SMI_ACK_RETRY_COUNT) {
+			dev_err(smi->dev, "ACK timeout\n");
+			return -ETIMEDOUT;
+		}
+	} while (1);
+
+	return 0;
+}
+
+static int realtek_smi_write_byte(struct realtek_smi *smi, u8 data)
+{
+	realtek_smi_write_bits(smi, data, 8);
+	return realtek_smi_wait_for_ack(smi);
+}
+
+static int realtek_smi_write_byte_noack(struct realtek_smi *smi, u8 data)
+{
+	realtek_smi_write_bits(smi, data, 8);
+	return 0;
+}
+
+static int realtek_smi_read_byte0(struct realtek_smi *smi, u8 *data)
+{
+	u32 t;
+
+	/* Read data */
+	realtek_smi_read_bits(smi, 8, &t);
+	*data = (t & 0xff);
+
+	/* Send an ACK */
+	realtek_smi_write_bits(smi, 0x00, 1);
+
+	return 0;
+}
+
+static int realtek_smi_read_byte1(struct realtek_smi *smi, u8 *data)
+{
+	u32 t;
+
+	/* Read data */
+	realtek_smi_read_bits(smi, 8, &t);
+	*data = (t & 0xff);
+
+	/* Send an ACK */
+	realtek_smi_write_bits(smi, 0x01, 1);
+
+	return 0;
+}
+
+static int realtek_smi_read_reg(struct realtek_smi *smi, u32 addr, u32 *data)
+{
+	unsigned long flags;
+	u8 lo = 0;
+	u8 hi = 0;
+	int ret;
+
+	spin_lock_irqsave(&smi->lock, flags);
+
+	realtek_smi_start(smi);
+
+	/* Send READ command */
+	ret = realtek_smi_write_byte(smi, smi->cmd_read);
+	if (ret)
+		goto out;
+
+	/* Set ADDR[7:0] */
+	ret = realtek_smi_write_byte(smi, addr & 0xff);
+	if (ret)
+		goto out;
+
+	/* Set ADDR[15:8] */
+	ret = realtek_smi_write_byte(smi, addr >> 8);
+	if (ret)
+		goto out;
+
+	/* Read DATA[7:0] */
+	realtek_smi_read_byte0(smi, &lo);
+	/* Read DATA[15:8] */
+	realtek_smi_read_byte1(smi, &hi);
+
+	*data = ((u32)lo) | (((u32)hi) << 8);
+
+	ret = 0;
+
+ out:
+	realtek_smi_stop(smi);
+	spin_unlock_irqrestore(&smi->lock, flags);
+
+	return ret;
+}
+
+static int realtek_smi_write_reg(struct realtek_smi *smi,
+				 u32 addr, u32 data, bool ack)
+{
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&smi->lock, flags);
+
+	realtek_smi_start(smi);
+
+	/* Send WRITE command */
+	ret = realtek_smi_write_byte(smi, smi->cmd_write);
+	if (ret)
+		goto out;
+
+	/* Set ADDR[7:0] */
+	ret = realtek_smi_write_byte(smi, addr & 0xff);
+	if (ret)
+		goto out;
+
+	/* Set ADDR[15:8] */
+	ret = realtek_smi_write_byte(smi, addr >> 8);
+	if (ret)
+		goto out;
+
+	/* Write DATA[7:0] */
+	ret = realtek_smi_write_byte(smi, data & 0xff);
+	if (ret)
+		goto out;
+
+	/* Write DATA[15:8] */
+	if (ack)
+		ret = realtek_smi_write_byte(smi, data >> 8);
+	else
+		ret = realtek_smi_write_byte_noack(smi, data >> 8);
+	if (ret)
+		goto out;
+
+	ret = 0;
+
+ out:
+	realtek_smi_stop(smi);
+	spin_unlock_irqrestore(&smi->lock, flags);
+
+	return ret;
+}
+
+/* There is one single case when we need to use this accessor and that
+ * is when issueing soft reset. Since the device reset as soon as we write
+ * that bit, no ACK will come back for natural reasons.
+ */
+int realtek_smi_write_reg_noack(struct realtek_smi *smi, u32 addr,
+				u32 data)
+{
+	return realtek_smi_write_reg(smi, addr, data, false);
+}
+EXPORT_SYMBOL_GPL(realtek_smi_write_reg_noack);
+
+/* Regmap accessors */
+
+static int realtek_smi_write(void *ctx, u32 reg, u32 val)
+{
+	struct realtek_smi *smi = ctx;
+
+	return realtek_smi_write_reg(smi, reg, val, true);
+}
+
+static int realtek_smi_read(void *ctx, u32 reg, u32 *val)
+{
+	struct realtek_smi *smi = ctx;
+
+	return realtek_smi_read_reg(smi, reg, val);
+}
+
+static const struct regmap_config realtek_smi_mdio_regmap_config = {
+	.reg_bits = 10, /* A4..A0 R4..R0 */
+	.val_bits = 16,
+	.reg_stride = 1,
+	/* PHY regs are at 0x8000 */
+	.max_register = 0xffff,
+	.reg_format_endian = REGMAP_ENDIAN_BIG,
+	.reg_read = realtek_smi_read,
+	.reg_write = realtek_smi_write,
+	.cache_type = REGCACHE_NONE,
+};
+
+static int realtek_smi_mdio_read(struct mii_bus *bus, int addr, int regnum)
+{
+	struct realtek_smi *smi = bus->priv;
+
+	return smi->ops->phy_read(smi, addr, regnum);
+}
+
+static int realtek_smi_mdio_write(struct mii_bus *bus, int addr, int regnum,
+				  u16 val)
+{
+	struct realtek_smi *smi = bus->priv;
+
+	return smi->ops->phy_write(smi, addr, regnum, val);
+}
+
+int realtek_smi_setup_mdio(struct realtek_smi *smi)
+{
+	struct device_node *mdio_np;
+	int ret;
+
+	mdio_np = of_find_compatible_node(smi->dev->of_node, NULL,
+					  "realtek,smi-mdio");
+	if (!mdio_np) {
+		dev_err(smi->dev, "no MDIO bus node\n");
+		return -ENODEV;
+	}
+
+	smi->slave_mii_bus = devm_mdiobus_alloc(smi->dev);
+	if (!smi->slave_mii_bus)
+		return -ENOMEM;
+	smi->slave_mii_bus->priv = smi;
+	smi->slave_mii_bus->name = "SMI slave MII";
+	smi->slave_mii_bus->read = realtek_smi_mdio_read;
+	smi->slave_mii_bus->write = realtek_smi_mdio_write;
+	snprintf(smi->slave_mii_bus->id, MII_BUS_ID_SIZE, "SMI-%d",
+		 smi->ds->index);
+	smi->slave_mii_bus->dev.of_node = mdio_np;
+	smi->slave_mii_bus->parent = smi->dev;
+	smi->ds->slave_mii_bus = smi->slave_mii_bus;
+
+	ret = of_mdiobus_register(smi->slave_mii_bus, mdio_np);
+	if (ret) {
+		dev_err(smi->dev, "unable to register MDIO bus %s\n",
+			smi->slave_mii_bus->id);
+		of_node_put(mdio_np);
+	}
+
+	return 0;
+}
+
+static int realtek_smi_probe(struct platform_device *pdev)
+{
+	const struct realtek_smi_variant *var;
+	struct device *dev = &pdev->dev;
+	struct realtek_smi *smi;
+	struct device_node *np;
+	int ret;
+
+	var = of_device_get_match_data(dev);
+	np = dev->of_node;
+
+	smi = devm_kzalloc(dev, sizeof(*smi), GFP_KERNEL);
+	if (!smi)
+		return -ENOMEM;
+	smi->map = devm_regmap_init(dev, NULL, smi,
+				    &realtek_smi_mdio_regmap_config);
+	if (IS_ERR(smi->map)) {
+		ret = PTR_ERR(smi->map);
+		dev_err(dev, "regmap init failed: %d\n", ret);
+		return ret;
+	}
+
+	/* Link forward and backward */
+	smi->dev = dev;
+	smi->clk_delay = var->clk_delay;
+	smi->cmd_read = var->cmd_read;
+	smi->cmd_write = var->cmd_write;
+	smi->ops = var->ops;
+
+	dev_set_drvdata(dev, smi);
+	spin_lock_init(&smi->lock);
+
+	/* TODO: if power is software controlled, set up any regulators here */
+
+	/* Assert then deassert RESET */
+	smi->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(smi->reset)) {
+		dev_err(dev, "failed to get RESET GPIO\n");
+		return PTR_ERR(smi->reset);
+	}
+	msleep(REALTEK_SMI_HW_STOP_DELAY);
+	gpiod_set_value(smi->reset, 0);
+	msleep(REALTEK_SMI_HW_START_DELAY);
+	dev_info(dev, "deasserted RESET\n");
+
+	/* Fetch MDIO pins */
+	smi->mdc = devm_gpiod_get_optional(dev, "mdc", GPIOD_OUT_LOW);
+	if (IS_ERR(smi->mdc))
+		return PTR_ERR(smi->mdc);
+	smi->mdio = devm_gpiod_get_optional(dev, "mdio", GPIOD_OUT_LOW);
+	if (IS_ERR(smi->mdio))
+		return PTR_ERR(smi->mdio);
+
+	smi->leds_disabled = of_property_read_bool(np, "realtek,disable-leds");
+
+	ret = smi->ops->detect(smi);
+	if (ret) {
+		dev_err(dev, "unable to detect switch\n");
+		return ret;
+	}
+
+	smi->ds = dsa_switch_alloc(dev, smi->num_ports);
+	if (!smi->ds)
+		return -ENOMEM;
+	smi->ds->priv = smi;
+
+	smi->ds->ops = var->ds_ops;
+	ret = dsa_register_switch(smi->ds);
+	if (ret) {
+		dev_err(dev, "unable to register switch ret = %d\n", ret);
+		return ret;
+	}
+	return 0;
+}
+
+static int realtek_smi_remove(struct platform_device *pdev)
+{
+	struct realtek_smi *smi = dev_get_drvdata(&pdev->dev);
+
+	dsa_unregister_switch(smi->ds);
+	gpiod_set_value(smi->reset, 1);
+
+	return 0;
+}
+
+static const struct of_device_id realtek_smi_of_match[] = {
+	{
+		.compatible = "realtek,rtl8366rb",
+		.data = &rtl8366rb_variant,
+	},
+	{
+		/* FIXME: add support for RTL8366S and more */
+		.compatible = "realtek,rtl8366s",
+		.data = NULL,
+	},
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, realtek_smi_of_match);
+
+static struct platform_driver realtek_smi_driver = {
+	.driver = {
+		.name = "realtek-smi",
+		.of_match_table = of_match_ptr(realtek_smi_of_match),
+	},
+	.probe  = realtek_smi_probe,
+	.remove = realtek_smi_remove,
+};
+module_platform_driver(realtek_smi_driver);

drivers/net/dsa/realtek-smi.h

+/* SPDX-License-Identifier: GPL-2.0+ */
+/* Realtek SMI interface driver defines
+ *
+ * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
+ * Copyright (C) 2009-2010 Gabor Juhos <juhosg@openwrt.org>
+ */
+
+#ifndef _REALTEK_SMI_H
+#define _REALTEK_SMI_H
+
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+#include <linux/gpio/consumer.h>
+#include <net/dsa.h>
+
+struct realtek_smi_ops;
+struct dentry;
+struct inode;
+struct file;
+
+struct rtl8366_mib_counter {
+	unsigned int	base;
+	unsigned int	offset;
+	unsigned int	length;
+	const char	*name;
+};
+
+struct rtl8366_vlan_mc {
+	u16	vid;
+	u16	untag;
+	u16	member;
+	u8	fid;
+	u8	priority;
+};
+
+struct rtl8366_vlan_4k {
+	u16	vid;
+	u16	untag;
+	u16	member;
+	u8	fid;
+};
+
+struct realtek_smi {
+	struct device		*dev;
+	struct gpio_desc	*reset;
+	struct gpio_desc	*mdc;
+	struct gpio_desc	*mdio;
+	struct regmap		*map;
+	struct mii_bus		*slave_mii_bus;
+
+	unsigned int		clk_delay;
+	u8			cmd_read;
+	u8			cmd_write;
+	spinlock_t		lock; /* Locks around command writes */
+	struct dsa_switch	*ds;
+	struct irq_domain	*irqdomain;
+	bool			leds_disabled;
+
+	unsigned int		cpu_port;
+	unsigned int		num_ports;
+	unsigned int		num_vlan_mc;
+	unsigned int		num_mib_counters;
+	struct rtl8366_mib_counter *mib_counters;
+
+	const struct realtek_smi_ops *ops;
+
+	int			vlan_enabled;
+	int			vlan4k_enabled;
+
+	char			buf[4096];
+};
+
+/**
+ * struct realtek_smi_ops - vtable for the per-SMI-chiptype operations
+ * @detect: detects the chiptype
+ */
+struct realtek_smi_ops {
+	int	(*detect)(struct realtek_smi *smi);
+	int	(*reset_chip)(struct realtek_smi *smi);
+	int	(*setup)(struct realtek_smi *smi);
+	void	(*cleanup)(struct realtek_smi *smi);
+	int	(*get_mib_counter)(struct realtek_smi *smi,
+				   int port,
+				   struct rtl8366_mib_counter *mib,
+				   u64 *mibvalue);
+	int	(*get_vlan_mc)(struct realtek_smi *smi, u32 index,
+			       struct rtl8366_vlan_mc *vlanmc);
+	int	(*set_vlan_mc)(struct realtek_smi *smi, u32 index,
+			       const struct rtl8366_vlan_mc *vlanmc);
+	int	(*get_vlan_4k)(struct realtek_smi *smi, u32 vid,
+			       struct rtl8366_vlan_4k *vlan4k);
+	int	(*set_vlan_4k)(struct realtek_smi *smi,
+			       const struct rtl8366_vlan_4k *vlan4k);
+	int	(*get_mc_index)(struct realtek_smi *smi, int port, int *val);
+	int	(*set_mc_index)(struct realtek_smi *smi, int port, int index);
+	bool	(*is_vlan_valid)(struct realtek_smi *smi, unsigned int vlan);
+	int	(*enable_vlan)(struct realtek_smi *smi, bool enable);
+	int	(*enable_vlan4k)(struct realtek_smi *smi, bool enable);
+	int	(*enable_port)(struct realtek_smi *smi, int port, bool enable);
+	int	(*phy_read)(struct realtek_smi *smi, int phy, int regnum);
+	int	(*phy_write)(struct realtek_smi *smi, int phy, int regnum,
+			     u16 val);
+};
+
+struct realtek_smi_variant {
+	const struct dsa_switch_ops *ds_ops;
+	const struct realtek_smi_ops *ops;
+	unsigned int clk_delay;
+	u8 cmd_read;
+	u8 cmd_write;
+};
+
+/* SMI core calls */
+int realtek_smi_write_reg_noack(struct realtek_smi *smi, u32 addr,
+				u32 data);
+int realtek_smi_setup_mdio(struct realtek_smi *smi);
+
+/* RTL8366 library helpers */
+int rtl8366_mc_is_used(struct realtek_smi *smi, int mc_index, int *used);
+int rtl8366_set_vlan(struct realtek_smi *smi, int vid, u32 member,
+		     u32 untag, u32 fid);
+int rtl8366_get_pvid(struct realtek_smi *smi, int port, int *val);
+int rtl8366_set_pvid(struct realtek_smi *smi, unsigned int port,
+		     unsigned int vid);
+int rtl8366_enable_vlan4k(struct realtek_smi *smi, bool enable);
+int rtl8366_enable_vlan(struct realtek_smi *smi, bool enable);
+int rtl8366_reset_vlan(struct realtek_smi *smi);
+int rtl8366_init_vlan(struct realtek_smi *smi);
+int rtl8366_vlan_filtering(struct dsa_switch *ds, int port,
+			   bool vlan_filtering);
+int rtl8366_vlan_prepare(struct dsa_switch *ds, int port,
+			 const struct switchdev_obj_port_vlan *vlan);
+void rtl8366_vlan_add(struct dsa_switch *ds, int port,
+		      const struct switchdev_obj_port_vlan *vlan);
+int rtl8366_vlan_del(struct dsa_switch *ds, int port,
+		     const struct switchdev_obj_port_vlan *vlan);
+void rtl8366_get_strings(struct dsa_switch *ds, int port, u32 stringset,
+			 uint8_t *data);
+int rtl8366_get_sset_count(struct dsa_switch *ds, int port, int sset);
+void rtl8366_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *data);
+
+extern const struct realtek_smi_variant rtl8366rb_variant;
+
+#endif /*  _REALTEK_SMI_H */

drivers/net/dsa/rtl8366.c

+// SPDX-License-Identifier: GPL-2.0
+/* Realtek SMI library helpers for the RTL8366x variants
+ * RTL8366RB and RTL8366S
+ *
+ * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
+ * Copyright (C) 2009-2010 Gabor Juhos <juhosg@openwrt.org>
+ * Copyright (C) 2010 Antti Seppälä <a.seppala@gmail.com>
+ * Copyright (C) 2010 Roman Yeryomin <roman@advem.lv>
+ * Copyright (C) 2011 Colin Leitner <colin.leitner@googlemail.com>
+ */
+#include <linux/if_bridge.h>
+#include <net/dsa.h>
+
+#include "realtek-smi.h"
+
+int rtl8366_mc_is_used(struct realtek_smi *smi, int mc_index, int *used)
+{
+	int ret;
+	int i;
+
+	*used = 0;
+	for (i = 0; i < smi->num_ports; i++) {
+		int index = 0;
+
+		ret = smi->ops->get_mc_index(smi, i, &index);
+		if (ret)
+			return ret;
+
+		if (mc_index == index) {
+			*used = 1;
+			break;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rtl8366_mc_is_used);
+
+int rtl8366_set_vlan(struct realtek_smi *smi, int vid, u32 member,
+		     u32 untag, u32 fid)
+{
+	struct rtl8366_vlan_4k vlan4k;
+	int ret;
+	int i;
+
+	/* Update the 4K table */
+	ret = smi->ops->get_vlan_4k(smi, vid, &vlan4k);
+	if (ret)
+		return ret;
+
+	vlan4k.member = member;
+	vlan4k.untag = untag;
+	vlan4k.fid = fid;
+	ret = smi->ops->set_vlan_4k(smi, &vlan4k);
+	if (ret)
+		return ret;
+
+	/* Try to find an existing MC entry for this VID */
+	for (i = 0; i < smi->num_vlan_mc; i++) {
+		struct rtl8366_vlan_mc vlanmc;
+
+		ret = smi->ops->get_vlan_mc(smi, i, &vlanmc);
+		if (ret)
+			return ret;
+
+		if (vid == vlanmc.vid) {
+			/* update the MC entry */
+			vlanmc.member = member;
+			vlanmc.untag = untag;
+			vlanmc.fid = fid;
+
+			ret = smi->ops->set_vlan_mc(smi, i, &vlanmc);
+			break;
+		}
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(rtl8366_set_vlan);
+
+int rtl8366_get_pvid(struct realtek_smi *smi, int port, int *val)
+{
+	struct rtl8366_vlan_mc vlanmc;
+	int ret;
+	int index;
+
+	ret = smi->ops->get_mc_index(smi, port, &index);
+	if (ret)
+		return ret;
+
+	ret = smi->ops->get_vlan_mc(smi, index, &vlanmc);
+	if (ret)
+		return ret;
+
+	*val = vlanmc.vid;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rtl8366_get_pvid);
+
+int rtl8366_set_pvid(struct realtek_smi *smi, unsigned int port,
+		     unsigned int vid)
+{
+	struct rtl8366_vlan_mc vlanmc;
+	struct rtl8366_vlan_4k vlan4k;
+	int ret;
+	int i;
+
+	/* Try to find an existing MC entry for this VID */
+	for (i = 0; i < smi->num_vlan_mc; i++) {
+		ret = smi->ops->get_vlan_mc(smi, i, &vlanmc);
+		if (ret)
+			return ret;
+
+		if (vid == vlanmc.vid) {
+			ret = smi->ops->set_vlan_mc(smi, i, &vlanmc);
+			if (ret)
+				return ret;
+
+			ret = smi->ops->set_mc_index(smi, port, i);
+			return ret;
+		}
+	}
+
+	/* We have no MC entry for this VID, try to find an empty one */
+	for (i = 0; i < smi->num_vlan_mc; i++) {
+		ret = smi->ops->get_vlan_mc(smi, i, &vlanmc);
+		if (ret)
+			return ret;
+
+		if (vlanmc.vid == 0 && vlanmc.member == 0) {
+			/* Update the entry from the 4K table */
+			ret = smi->ops->get_vlan_4k(smi, vid, &vlan4k);
+			if (ret)
+				return ret;
+
+			vlanmc.vid = vid;
+			vlanmc.member = vlan4k.member;
+			vlanmc.untag = vlan4k.untag;
+			vlanmc.fid = vlan4k.fid;
+			ret = smi->ops->set_vlan_mc(smi, i, &vlanmc);
+			if (ret)
+				return ret;
+
+			ret = smi->ops->set_mc_index(smi, port, i);
+			return ret;
+		}
+	}
+
+	/* MC table is full, try to find an unused entry and replace it */
+	for (i = 0; i < smi->num_vlan_mc; i++) {
+		int used;
+
+		ret = rtl8366_mc_is_used(smi, i, &used);
+		if (ret)
+			return ret;
+
+		if (!used) {
+			/* Update the entry from the 4K table */
+			ret = smi->ops->get_vlan_4k(smi, vid, &vlan4k);
+			if (ret)
+				return ret;
+
+			vlanmc.vid = vid;
+			vlanmc.member = vlan4k.member;
+			vlanmc.untag = vlan4k.untag;
+			vlanmc.fid = vlan4k.fid;
+			ret = smi->ops->set_vlan_mc(smi, i, &vlanmc);
+			if (ret)
+				return ret;
+
+			ret = smi->ops->set_mc_index(smi, port, i);
+			return ret;
+		}
+	}
+
+	dev_err(smi->dev,
+		"all VLAN member configurations are in use\n");
+
+	return -ENOSPC;
+}
+EXPORT_SYMBOL_GPL(rtl8366_set_pvid);
+
+int rtl8366_enable_vlan4k(struct realtek_smi *smi, bool enable)
+{
+	int ret;
+
+	/* To enable 4k VLAN, ordinary VLAN must be enabled first,
+	 * but if we disable 4k VLAN it is fine to leave ordinary
+	 * VLAN enabled.
+	 */
+	if (enable) {
+		/* Make sure VLAN is ON */
+		ret = smi->ops->enable_vlan(smi, true);
+		if (ret)
+			return ret;
+
+		smi->vlan_enabled = true;
+	}
+
+	ret = smi->ops->enable_vlan4k(smi, enable);
+	if (ret)
+		return ret;
+
+	smi->vlan4k_enabled = enable;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rtl8366_enable_vlan4k);
+
+int rtl8366_enable_vlan(struct realtek_smi *smi, bool enable)
+{
+	int ret;
+
+	ret = smi->ops->enable_vlan(smi, enable);
+	if (ret)
+		return ret;
+
+	smi->vlan_enabled = enable;
+
+	/* If we turn VLAN off, make sure that we turn off
+	 * 4k VLAN as well, if that happened to be on.
+	 */
+	if (!enable) {
+		smi->vlan4k_enabled = false;
+		ret = smi->ops->enable_vlan4k(smi, false);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(rtl8366_enable_vlan);
+
+int rtl8366_reset_vlan(struct realtek_smi *smi)
+{
+	struct rtl8366_vlan_mc vlanmc;
+	struct rtl8366_vlan_4k vlan4k;
+	int ret;
+	int i;
+
+	rtl8366_enable_vlan(smi, false);
+	rtl8366_enable_vlan4k(smi, false);
+
+	/* Clear the 16 VLAN member configurations */
+	vlanmc.vid = 0;
+	vlanmc.priority = 0;
+	vlanmc.member = 0;
+	vlanmc.untag = 0;
+	vlanmc.fid = 0;
+	for (i = 0; i < smi->num_vlan_mc; i++) {
+		ret = smi->ops->set_vlan_mc(smi, i, &vlanmc);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rtl8366_reset_vlan);
+
+int rtl8366_init_vlan(struct realtek_smi *smi)
+{
+	int port;
+	int ret;
+
+	ret = rtl8366_reset_vlan(smi);
+	if (ret)
+		return ret;
+
+	/* Loop over the available ports, for each port, associate
+	 * it with the VLAN (port+1)
+	 */
+	for (port = 0; port < smi->num_ports; port++) {
+		u32 mask;
+
+		if (port == smi->cpu_port)
+			/* For the CPU port, make all ports members of this
+			 * VLAN.
+			 */
+			mask = GENMASK(smi->num_ports - 1, 0);
+		else
+			/* For all other ports, enable itself plus the
+			 * CPU port.
+			 */
+			mask = BIT(port) | BIT(smi->cpu_port);
+
+		/* For each port, set the port as member of VLAN (port+1)
+		 * and untagged, except for the CPU port: the CPU port (5) is
+		 * member of VLAN 6 and so are ALL the other ports as well.
+		 * Use filter 0 (no filter).
+		 */
+		dev_info(smi->dev, "VLAN%d port mask for port %d, %08x\n",
+			 (port + 1), port, mask);
+		ret = rtl8366_set_vlan(smi, (port + 1), mask, mask, 0);
+		if (ret)
+			return ret;
+
+		dev_info(smi->dev, "VLAN%d port %d, PVID set to %d\n",
+			 (port + 1), port, (port + 1));
+		ret = rtl8366_set_pvid(smi, port, (port + 1));
+		if (ret)
+			return ret;
+	}
+
+	return rtl8366_enable_vlan(smi, true);
+}
+EXPORT_SYMBOL_GPL(rtl8366_init_vlan);
+
+int rtl8366_vlan_filtering(struct dsa_switch *ds, int port, bool vlan_filtering)
+{
+	struct realtek_smi *smi = ds->priv;
+	struct rtl8366_vlan_4k vlan4k;
+	int ret;
+
+	if (!smi->ops->is_vlan_valid(smi, port))
+		return -EINVAL;
+
+	dev_info(smi->dev, "%s filtering on port %d\n",
+		 vlan_filtering ? "enable" : "disable",
+		 port);
+
+	/* TODO:
+	 * The hardware support filter ID (FID) 0..7, I have no clue how to
+	 * support this in the driver when the callback only says on/off.
+	 */
+	ret = smi->ops->get_vlan_4k(smi, port, &vlan4k);
+	if (ret)
+		return ret;
+
+	/* Just set the filter to FID 1 for now then */
+	ret = rtl8366_set_vlan(smi, port,
+			       vlan4k.member,
+			       vlan4k.untag,
+			       1);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rtl8366_vlan_filtering);
+
+int rtl8366_vlan_prepare(struct dsa_switch *ds, int port,
+			 const struct switchdev_obj_port_vlan *vlan)
+{
+	struct realtek_smi *smi = ds->priv;
+	int ret;
+
+	if (!smi->ops->is_vlan_valid(smi, port))
+		return -EINVAL;
+
+	dev_info(smi->dev, "prepare VLANs %04x..%04x\n",
+		 vlan->vid_begin, vlan->vid_end);
+
+	/* Enable VLAN in the hardware
+	 * FIXME: what's with this 4k business?
+	 * Just rtl8366_enable_vlan() seems inconclusive.
+	 */
+	ret = rtl8366_enable_vlan4k(smi, true);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rtl8366_vlan_prepare);
+
+void rtl8366_vlan_add(struct dsa_switch *ds, int port,
+		      const struct switchdev_obj_port_vlan *vlan)
+{
+	bool untagged = !!(vlan->flags & BRIDGE_VLAN_INFO_UNTAGGED);
+	bool pvid = !!(vlan->flags & BRIDGE_VLAN_INFO_PVID);
+	struct realtek_smi *smi = ds->priv;
+	u32 member = 0;
+	u32 untag = 0;
+	u16 vid;
+	int ret;
+
+	if (!smi->ops->is_vlan_valid(smi, port))
+		return;
+
+	dev_info(smi->dev, "add VLAN on port %d, %s, %s\n",
+		 port,
+		 untagged ? "untagged" : "tagged",
+		 pvid ? " PVID" : "no PVID");
+
+	if (dsa_is_dsa_port(ds, port) || dsa_is_cpu_port(ds, port))
+		dev_err(smi->dev, "port is DSA or CPU port\n");
+
+	for (vid = vlan->vid_begin; vid <= vlan->vid_end; ++vid) {
+		int pvid_val = 0;
+
+		dev_info(smi->dev, "add VLAN %04x\n", vid);
+		member |= BIT(port);
+
+		if (untagged)
+			untag |= BIT(port);
+
+		/* To ensure that we have a valid MC entry for this VLAN,
+		 * initialize the port VLAN ID here.
+		 */
+		ret = rtl8366_get_pvid(smi, port, &pvid_val);
+		if (ret < 0) {
+			dev_err(smi->dev, "could not lookup PVID for port %d\n",
+				port);
+			return;
+		}
+		if (pvid_val == 0) {
+			ret = rtl8366_set_pvid(smi, port, vid);
+			if (ret < 0)
+				return;
+		}
+	}
+
+	ret = rtl8366_set_vlan(smi, port, member, untag, 0);
+	if (ret)
+		dev_err(smi->dev,
+			"failed to set up VLAN %04x",
+			vid);
+}
+EXPORT_SYMBOL_GPL(rtl8366_vlan_add);
+
+int rtl8366_vlan_del(struct dsa_switch *ds, int port,
+		     const struct switchdev_obj_port_vlan *vlan)
+{
+	struct realtek_smi *smi = ds->priv;
+	u16 vid;
+	int ret;
+
+	dev_info(smi->dev, "del VLAN on port %d\n", port);
+
+	for (vid = vlan->vid_begin; vid <= vlan->vid_end; ++vid) {
+		int i;
+
+		dev_info(smi->dev, "del VLAN %04x\n", vid);
+
+		for (i = 0; i < smi->num_vlan_mc; i++) {
+			struct rtl8366_vlan_mc vlanmc;
+
+			ret = smi->ops->get_vlan_mc(smi, i, &vlanmc);
+			if (ret)
+				return ret;
+
+			if (vid == vlanmc.vid) {
+				/* clear VLAN member configurations */
+				vlanmc.vid = 0;
+				vlanmc.priority = 0;
+				vlanmc.member = 0;
+				vlanmc.untag = 0;
+				vlanmc.fid = 0;
+
+				ret = smi->ops->set_vlan_mc(smi, i, &vlanmc);
+				if (ret) {
+					dev_err(smi->dev,
+						"failed to remove VLAN %04x\n",
+						vid);
+					return ret;
+				}
+				break;
+			}
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rtl8366_vlan_del);
+
+void rtl8366_get_strings(struct dsa_switch *ds, int port, u32 stringset,
+			 uint8_t *data)
+{
+	struct realtek_smi *smi = ds->priv;
+	struct rtl8366_mib_counter *mib;
+	int i;
+
+	if (port >= smi->num_ports)
+		return;
+
+	for (i = 0; i < smi->num_mib_counters; i++) {
+		mib = &smi->mib_counters[i];
+		strncpy(data + i * ETH_GSTRING_LEN,
+			mib->name, ETH_GSTRING_LEN);
+	}
+}
+EXPORT_SYMBOL_GPL(rtl8366_get_strings);
+
+int rtl8366_get_sset_count(struct dsa_switch *ds, int port, int sset)
+{
+	struct realtek_smi *smi = ds->priv;
+
+	/* We only support SS_STATS */
+	if (sset != ETH_SS_STATS)
+		return 0;
+	if (port >= smi->num_ports)
+		return -EINVAL;
+
+	return smi->num_mib_counters;
+}
+EXPORT_SYMBOL_GPL(rtl8366_get_sset_count);
+
+void rtl8366_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *data)
+{
+	struct realtek_smi *smi = ds->priv;
+	int i;
+	int ret;
+
+	if (port >= smi->num_ports)
+		return;
+
+	for (i = 0; i < smi->num_mib_counters; i++) {
+		struct rtl8366_mib_counter *mib;
+		u64 mibvalue = 0;
+
+		mib = &smi->mib_counters[i];
+		ret = smi->ops->get_mib_counter(smi, port, mib, &mibvalue);
+		if (ret) {
+			dev_err(smi->dev, "error reading MIB counter %s\n",
+				mib->name);
+		}
+		data[i] = mibvalue;
+	}
+}
+EXPORT_SYMBOL_GPL(rtl8366_get_ethtool_stats);