net: dsa: realtek: add new mdio interface for drivers

This driver is a mdio_driver instead of a platform driver (like
realtek-smi).

ds_ops was duplicated for smi and mdio usage as mdio interfaces uses
phy_{read,write} in ds_ops and the presence of phy_read is incompatible
with external slave_mii_bus allocation.

Signed-off-by: Luiz Angelo Daros de Luca <[e-mail]>
Tested-by: Arınç ÜNAL <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/dsa/realtek/Kconfig

···
 	help
 	  Select to enable support for Realtek Ethernet switch chips.
 
+config NET_DSA_REALTEK_MDIO
+	tristate "Realtek MDIO connected switch driver"
+	depends on NET_DSA_REALTEK
+	default y
+	help
+	  Select to enable support for registering switches configured
+	  through MDIO.
+
 config NET_DSA_REALTEK_SMI
 	tristate "Realtek SMI connected switch driver"
 	depends on NET_DSA_REALTEK
···
 	tristate "Realtek RTL8365MB switch subdriver"
 	default y
 	depends on NET_DSA_REALTEK
-	depends on NET_DSA_REALTEK_SMI
+	depends on NET_DSA_REALTEK_SMI || NET_DSA_REALTEK_MDIO
 	select NET_DSA_TAG_RTL8_4
 	help
 	  Select to enable support for Realtek RTL8365MB
···
 	tristate "Realtek RTL8366RB switch subdriver"
 	default y
 	depends on NET_DSA_REALTEK
-	depends on NET_DSA_REALTEK_SMI
+	depends on NET_DSA_REALTEK_SMI || NET_DSA_REALTEK_MDIO
 	select NET_DSA_TAG_RTL4_A
 	help
 	  Select to enable support for Realtek RTL8366RB

drivers/net/dsa/realtek/Makefile

···
 # SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_NET_DSA_REALTEK_MDIO) 	+= realtek-mdio.o
 obj-$(CONFIG_NET_DSA_REALTEK_SMI) 	+= realtek-smi.o
 obj-$(CONFIG_NET_DSA_REALTEK_RTL8366RB) += rtl8366.o
 rtl8366-objs 				:= rtl8366-core.o rtl8366rb.o

drivers/net/dsa/realtek/realtek-mdio.c

···
+// SPDX-License-Identifier: GPL-2.0+
+/* Realtek MDIO interface driver
+ *
+ * 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 <[e-mail]>
+ * Copyright (C) 2010 Antti Seppälä <[e-mail]>
+ * Copyright (C) 2010 Roman Yeryomin <[e-mail]>
+ * Copyright (C) 2011 Colin Leitner <[e-mail]>
+ * Copyright (C) 2009-2010 Gabor Juhos <[e-mail]>
+ */
+
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+
+#include "realtek.h"
+
+/* Read/write via mdiobus */
+#define REALTEK_MDIO_CTRL0_REG		31
+#define REALTEK_MDIO_START_REG		29
+#define REALTEK_MDIO_CTRL1_REG		21
+#define REALTEK_MDIO_ADDRESS_REG	23
+#define REALTEK_MDIO_DATA_WRITE_REG	24
+#define REALTEK_MDIO_DATA_READ_REG	25
+
+#define REALTEK_MDIO_START_OP		0xFFFF
+#define REALTEK_MDIO_ADDR_OP		0x000E
+#define REALTEK_MDIO_READ_OP		0x0001
+#define REALTEK_MDIO_WRITE_OP		0x0003
+
+static int realtek_mdio_write(void *ctx, u32 reg, u32 val)
+{
+	struct realtek_priv *priv = ctx;
+	struct mii_bus *bus = priv->bus;
+	int ret;
+
+	mutex_lock(&bus->mdio_lock);
+
+	ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_CTRL0_REG, REALTEK_MDIO_ADDR_OP);
+	if (ret)
+		goto out_unlock;
+
+	ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_ADDRESS_REG, reg);
+	if (ret)
+		goto out_unlock;
+
+	ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_DATA_WRITE_REG, val);
+	if (ret)
+		goto out_unlock;
+
+	ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_CTRL1_REG, REALTEK_MDIO_WRITE_OP);
+
+out_unlock:
+	mutex_unlock(&bus->mdio_lock);
+
+	return ret;
+}
+
+static int realtek_mdio_read(void *ctx, u32 reg, u32 *val)
+{
+	struct realtek_priv *priv = ctx;
+	struct mii_bus *bus = priv->bus;
+	int ret;
+
+	mutex_lock(&bus->mdio_lock);
+
+	ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_CTRL0_REG, REALTEK_MDIO_ADDR_OP);
+	if (ret)
+		goto out_unlock;
+
+	ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_ADDRESS_REG, reg);
+	if (ret)
+		goto out_unlock;
+
+	ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_CTRL1_REG, REALTEK_MDIO_READ_OP);
+	if (ret)
+		goto out_unlock;
+
+	ret = bus->read(bus, priv->mdio_addr, REALTEK_MDIO_DATA_READ_REG);
+	if (ret >= 0) {
+		*val = ret;
+		ret = 0;
+	}
+
+out_unlock:
+	mutex_unlock(&bus->mdio_lock);
+
+	return ret;
+}
+
+static const struct regmap_config realtek_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_mdio_read,
+	.reg_write = realtek_mdio_write,
+	.cache_type = REGCACHE_NONE,
+};
+
+static int realtek_mdio_probe(struct mdio_device *mdiodev)
+{
+	struct realtek_priv *priv;
+	struct device *dev = &mdiodev->dev;
+	const struct realtek_variant *var;
+	int ret;
+	struct device_node *np;
+
+	var = of_device_get_match_data(dev);
+	if (!var)
+		return -EINVAL;
+
+	priv = devm_kzalloc(&mdiodev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->map = devm_regmap_init(dev, NULL, priv, &realtek_mdio_regmap_config);
+	if (IS_ERR(priv->map)) {
+		ret = PTR_ERR(priv->map);
+		dev_err(dev, "regmap init failed: %d\n", ret);
+		return ret;
+	}
+
+	priv->mdio_addr = mdiodev->addr;
+	priv->bus = mdiodev->bus;
+	priv->dev = &mdiodev->dev;
+	priv->chip_data = (void *)priv + sizeof(*priv);
+
+	priv->clk_delay = var->clk_delay;
+	priv->cmd_read = var->cmd_read;
+	priv->cmd_write = var->cmd_write;
+	priv->ops = var->ops;
+
+	priv->write_reg_noack = realtek_mdio_write;
+
+	np = dev->of_node;
+
+	dev_set_drvdata(dev, priv);
+
+	/* TODO: if power is software controlled, set up any regulators here */
+	priv->leds_disabled = of_property_read_bool(np, "realtek,disable-leds");
+
+	ret = priv->ops->detect(priv);
+	if (ret) {
+		dev_err(dev, "unable to detect switch\n");
+		return ret;
+	}
+
+	priv->ds = devm_kzalloc(dev, sizeof(*priv->ds), GFP_KERNEL);
+	if (!priv->ds)
+		return -ENOMEM;
+
+	priv->ds->dev = dev;
+	priv->ds->num_ports = priv->num_ports;
+	priv->ds->priv = priv;
+	priv->ds->ops = var->ds_ops_mdio;
+
+	ret = dsa_register_switch(priv->ds);
+	if (ret) {
+		dev_err(priv->dev, "unable to register switch ret = %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void realtek_mdio_remove(struct mdio_device *mdiodev)
+{
+	struct realtek_priv *priv = dev_get_drvdata(&mdiodev->dev);
+
+	if (!priv)
+		return;
+
+	dsa_unregister_switch(priv->ds);
+
+	dev_set_drvdata(&mdiodev->dev, NULL);
+}
+
+static void realtek_mdio_shutdown(struct mdio_device *mdiodev)
+{
+	struct realtek_priv *priv = dev_get_drvdata(&mdiodev->dev);
+
+	if (!priv)
+		return;
+
+	dsa_switch_shutdown(priv->ds);
+
+	dev_set_drvdata(&mdiodev->dev, NULL);
+}
+
+static const struct of_device_id realtek_mdio_of_match[] = {
+#if IS_ENABLED(CONFIG_NET_DSA_REALTEK_RTL8366RB)
+	{ .compatible = "realtek,rtl8366rb", .data = &rtl8366rb_variant, },
+#endif
+#if IS_ENABLED(CONFIG_NET_DSA_REALTEK_RTL8365MB)
+	{ .compatible = "realtek,rtl8365mb", .data = &rtl8365mb_variant, },
+#endif
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, realtek_mdio_of_match);
+
+static struct mdio_driver realtek_mdio_driver = {
+	.mdiodrv.driver = {
+		.name = "realtek-mdio",
+		.of_match_table = of_match_ptr(realtek_mdio_of_match),
+	},
+	.probe  = realtek_mdio_probe,
+	.remove = realtek_mdio_remove,
+	.shutdown = realtek_mdio_shutdown,
+};
+
+mdio_module_driver(realtek_mdio_driver);
+
+MODULE_AUTHOR("Luiz Angelo Daros de Luca <[e-mail]>");
+MODULE_DESCRIPTION("Driver for Realtek ethernet switch connected via MDIO interface");
+MODULE_LICENSE("GPL");

drivers/net/dsa/realtek/realtek-smi.c

···
 	priv->ds->num_ports = priv->num_ports;
 	priv->ds->priv = priv;
 
-	priv->ds->ops = var->ds_ops;
+	priv->ds->ops = var->ds_ops_smi;
 	ret = dsa_register_switch(priv->ds);
 	if (ret) {
 		dev_err_probe(dev, ret, "unable to register switch\n");

drivers/net/dsa/realtek/realtek.h

···
 	struct gpio_desc	*mdio;
 	struct regmap		*map;
 	struct mii_bus		*slave_mii_bus;
+	struct mii_bus		*bus;
+	int			mdio_addr;
 
 	unsigned int		clk_delay;
 	u8			cmd_read;
···
 };
 
 struct realtek_variant {
-	const struct dsa_switch_ops *ds_ops;
+	const struct dsa_switch_ops *ds_ops_smi;
+	const struct dsa_switch_ops *ds_ops_mdio;
 	const struct realtek_ops *ops;
 	unsigned int clk_delay;
 	u8 cmd_read;

drivers/net/dsa/realtek/rtl8365mb.c

···
 	return 0;
 }
 
+static int rtl8365mb_dsa_phy_read(struct dsa_switch *ds, int phy, int regnum)
+{
+	return rtl8365mb_phy_read(ds->priv, phy, regnum);
+}
+
+static int rtl8365mb_dsa_phy_write(struct dsa_switch *ds, int phy, int regnum,
+				   u16 val)
+{
+	return rtl8365mb_phy_write(ds->priv, phy, regnum, val);
+}
+
 static enum dsa_tag_protocol
 rtl8365mb_get_tag_protocol(struct dsa_switch *ds, int port,
 			   enum dsa_tag_protocol mp)
···
 	return 0;
 }
 
-static const struct dsa_switch_ops rtl8365mb_switch_ops = {
+static const struct dsa_switch_ops rtl8365mb_switch_ops_smi = {
 	.get_tag_protocol = rtl8365mb_get_tag_protocol,
 	.setup = rtl8365mb_setup,
 	.teardown = rtl8365mb_teardown,
···
 	.get_stats64 = rtl8365mb_get_stats64,
 };
 
+static const struct dsa_switch_ops rtl8365mb_switch_ops_mdio = {
+	.get_tag_protocol = rtl8365mb_get_tag_protocol,
+	.setup = rtl8365mb_setup,
+	.teardown = rtl8365mb_teardown,
+	.phylink_validate = rtl8365mb_phylink_validate,
+	.phylink_mac_config = rtl8365mb_phylink_mac_config,
+	.phylink_mac_link_down = rtl8365mb_phylink_mac_link_down,
+	.phylink_mac_link_up = rtl8365mb_phylink_mac_link_up,
+	.phy_read = rtl8365mb_dsa_phy_read,
+	.phy_write = rtl8365mb_dsa_phy_write,
+	.port_stp_state_set = rtl8365mb_port_stp_state_set,
+	.get_strings = rtl8365mb_get_strings,
+	.get_ethtool_stats = rtl8365mb_get_ethtool_stats,
+	.get_sset_count = rtl8365mb_get_sset_count,
+	.get_eth_phy_stats = rtl8365mb_get_phy_stats,
+	.get_eth_mac_stats = rtl8365mb_get_mac_stats,
+	.get_eth_ctrl_stats = rtl8365mb_get_ctrl_stats,
+	.get_stats64 = rtl8365mb_get_stats64,
+};
+
 static const struct realtek_ops rtl8365mb_ops = {
 	.detect = rtl8365mb_detect,
 	.phy_read = rtl8365mb_phy_read,
···
 };
 
 const struct realtek_variant rtl8365mb_variant = {
-	.ds_ops = &rtl8365mb_switch_ops,
+	.ds_ops_smi = &rtl8365mb_switch_ops_smi,
+	.ds_ops_mdio = &rtl8365mb_switch_ops_mdio,
 	.ops = &rtl8365mb_ops,
 	.clk_delay = 10,
 	.cmd_read = 0xb9,

drivers/net/dsa/realtek/rtl8366rb.c

···
 	return 0;
 }
 
+static int rtl8366rb_dsa_phy_read(struct dsa_switch *ds, int phy, int regnum)
+{
+	return rtl8366rb_phy_read(ds->priv, phy, regnum);
+}
+
+static int rtl8366rb_dsa_phy_write(struct dsa_switch *ds, int phy, int regnum,
+				   u16 val)
+{
+	return rtl8366rb_phy_write(ds->priv, phy, regnum, val);
+}
+
 static int rtl8366rb_reset_chip(struct realtek_priv *priv)
 {
 	int timeout = 10;
···
 	return 0;
 }
 
-static const struct dsa_switch_ops rtl8366rb_switch_ops = {
+static const struct dsa_switch_ops rtl8366rb_switch_ops_smi = {
 	.get_tag_protocol = rtl8366_get_tag_protocol,
 	.setup = rtl8366rb_setup,
+	.phylink_mac_link_up = rtl8366rb_mac_link_up,
+	.phylink_mac_link_down = rtl8366rb_mac_link_down,
+	.get_strings = rtl8366_get_strings,
+	.get_ethtool_stats = rtl8366_get_ethtool_stats,
+	.get_sset_count = rtl8366_get_sset_count,
+	.port_bridge_join = rtl8366rb_port_bridge_join,
+	.port_bridge_leave = rtl8366rb_port_bridge_leave,
+	.port_vlan_filtering = rtl8366rb_vlan_filtering,
+	.port_vlan_add = rtl8366_vlan_add,
+	.port_vlan_del = rtl8366_vlan_del,
+	.port_enable = rtl8366rb_port_enable,
+	.port_disable = rtl8366rb_port_disable,
+	.port_pre_bridge_flags = rtl8366rb_port_pre_bridge_flags,
+	.port_bridge_flags = rtl8366rb_port_bridge_flags,
+	.port_stp_state_set = rtl8366rb_port_stp_state_set,
+	.port_fast_age = rtl8366rb_port_fast_age,
+	.port_change_mtu = rtl8366rb_change_mtu,
+	.port_max_mtu = rtl8366rb_max_mtu,
+};
+
+static const struct dsa_switch_ops rtl8366rb_switch_ops_mdio = {
+	.get_tag_protocol = rtl8366_get_tag_protocol,
+	.setup = rtl8366rb_setup,
+	.phy_read = rtl8366rb_dsa_phy_read,
+	.phy_write = rtl8366rb_dsa_phy_write,
 	.phylink_mac_link_up = rtl8366rb_mac_link_up,
 	.phylink_mac_link_down = rtl8366rb_mac_link_down,
 	.get_strings = rtl8366_get_strings,
···
 };
 
 const struct realtek_variant rtl8366rb_variant = {
-	.ds_ops = &rtl8366rb_switch_ops,
+	.ds_ops_smi = &rtl8366rb_switch_ops_smi,
+	.ds_ops_mdio = &rtl8366rb_switch_ops_mdio,
 	.ops = &rtl8366rb_ops,
 	.clk_delay = 10,
 	.cmd_read = 0xa9,