net: dsa: mt7530: introduce separate MDIO driver

Split MT7530 switch driver into a common part and a part specific
for MDIO connected switches and multi-chip modules.
Move MDIO-specific functions to newly introduced mt7530-mdio.c while
keeping the common parts in mt7530.c.
Introduce new Kconfig symbol CONFIG_NET_DSA_MT7530_MDIO which is
implied by CONFIG_NET_DSA_MT7530.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

MAINTAINERS

@@ -13177,6 +13177,7 @@ M:	Landen Chao <Landen.Chao@mediatek.com>
 M:	DENG Qingfang <dqfext@gmail.com>
 L:	netdev@vger.kernel.org
 S:	Maintained
+F:	drivers/net/dsa/mt7530-mdio.c
 F:	drivers/net/dsa/mt7530.*
 F:	net/dsa/tag_mtk.c
 

drivers/net/dsa/Kconfig

@@ -38,11 +38,22 @@ config NET_DSA_MT7530
 	tristate "MediaTek MT7530 and MT7531 Ethernet switch support"
 	select NET_DSA_TAG_MTK
 	select MEDIATEK_GE_PHY
-	select PCS_MTK_LYNXI
+	imply NET_DSA_MT7530_MDIO
 	help
 	  This enables support for the MediaTek MT7530 and MT7531 Ethernet
 	  switch chips. Multi-chip module MT7530 in MT7621AT, MT7621DAT,
-	  MT7621ST and MT7623AI SoCs is supported.
+	  MT7621ST and MT7623AI SoCs, and built-in switch in MT7988 SoC are
+	  supported as well.
+
+config NET_DSA_MT7530_MDIO
+	tristate "MediaTek MT7530 MDIO interface driver"
+	depends on NET_DSA_MT7530
+	select PCS_MTK_LYNXI
+	help
+	  This enables support for the MediaTek MT7530 and MT7531 switch
+	  chips which are connected via MDIO, as well as multi-chip
+	  module MT7530 which can be found in the MT7621AT, MT7621DAT,
+	  MT7621ST and MT7623AI SoCs.
 
 config NET_DSA_MV88E6060
 	tristate "Marvell 88E6060 ethernet switch chip support"

drivers/net/dsa/Makefile

@@ -7,6 +7,7 @@ obj-$(CONFIG_FIXED_PHY)		+= dsa_loop_bdinfo.o
 endif
 obj-$(CONFIG_NET_DSA_LANTIQ_GSWIP) += lantiq_gswip.o
 obj-$(CONFIG_NET_DSA_MT7530)	+= mt7530.o
+obj-$(CONFIG_NET_DSA_MT7530_MDIO) += mt7530-mdio.o
 obj-$(CONFIG_NET_DSA_MV88E6060) += mv88e6060.o
 obj-$(CONFIG_NET_DSA_RZN1_A5PSW) += rzn1_a5psw.o
 obj-$(CONFIG_NET_DSA_SMSC_LAN9303) += lan9303-core.o

drivers/net/dsa/mt7530-mdio.c

@@ -0,0 +1,271 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/gpio/consumer.h>
+#include <linux/mdio.h>
+#include <linux/module.h>
+#include <linux/pcs/pcs-mtk-lynxi.h>
+#include <linux/of_irq.h>
+#include <linux/of_mdio.h>
+#include <linux/of_net.h>
+#include <linux/of_platform.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+#include <linux/regulator/consumer.h>
+#include <net/dsa.h>
+
+#include "mt7530.h"
+
+static int
+mt7530_regmap_write(void *context, unsigned int reg, unsigned int val)
+{
+	struct mii_bus *bus = context;
+	u16 page, r, lo, hi;
+	int ret;
+
+	page = (reg >> 6) & 0x3ff;
+	r  = (reg >> 2) & 0xf;
+	lo = val & 0xffff;
+	hi = val >> 16;
+
+	/* MT7530 uses 31 as the pseudo port */
+	ret = bus->write(bus, 0x1f, 0x1f, page);
+	if (ret < 0)
+		return ret;
+
+	ret = bus->write(bus, 0x1f, r,  lo);
+	if (ret < 0)
+		return ret;
+
+	ret = bus->write(bus, 0x1f, 0x10, hi);
+	return ret;
+}
+
+static int
+mt7530_regmap_read(void *context, unsigned int reg, unsigned int *val)
+{
+	struct mii_bus *bus = context;
+	u16 page, r, lo, hi;
+	int ret;
+
+	page = (reg >> 6) & 0x3ff;
+	r = (reg >> 2) & 0xf;
+
+	/* MT7530 uses 31 as the pseudo port */
+	ret = bus->write(bus, 0x1f, 0x1f, page);
+	if (ret < 0)
+		return ret;
+
+	lo = bus->read(bus, 0x1f, r);
+	hi = bus->read(bus, 0x1f, 0x10);
+
+	*val = (hi << 16) | (lo & 0xffff);
+
+	return 0;
+}
+
+static void
+mt7530_mdio_regmap_lock(void *mdio_lock)
+{
+	mutex_lock_nested(mdio_lock, MDIO_MUTEX_NESTED);
+}
+
+static void
+mt7530_mdio_regmap_unlock(void *mdio_lock)
+{
+	mutex_unlock(mdio_lock);
+}
+
+static const struct regmap_bus mt7530_regmap_bus = {
+	.reg_write = mt7530_regmap_write,
+	.reg_read = mt7530_regmap_read,
+};
+
+static int
+mt7531_create_sgmii(struct mt7530_priv *priv)
+{
+	struct regmap_config *mt7531_pcs_config[2];
+	struct phylink_pcs *pcs;
+	struct regmap *regmap;
+	int i, ret = 0;
+
+	for (i = 0; i < 2; i++) {
+		mt7531_pcs_config[i] = devm_kzalloc(priv->dev,
+						    sizeof(struct regmap_config),
+						    GFP_KERNEL);
+		if (!mt7531_pcs_config[i]) {
+			ret = -ENOMEM;
+			break;
+		}
+
+		mt7531_pcs_config[i]->name = i ? "port6" : "port5";
+		mt7531_pcs_config[i]->reg_bits = 16;
+		mt7531_pcs_config[i]->val_bits = 32;
+		mt7531_pcs_config[i]->reg_stride = 4;
+		mt7531_pcs_config[i]->reg_base = MT7531_SGMII_REG_BASE(5 + i);
+		mt7531_pcs_config[i]->max_register = 0x17c;
+		mt7531_pcs_config[i]->lock = mt7530_mdio_regmap_lock;
+		mt7531_pcs_config[i]->unlock = mt7530_mdio_regmap_unlock;
+		mt7531_pcs_config[i]->lock_arg = &priv->bus->mdio_lock;
+
+		regmap = devm_regmap_init(priv->dev,
+					  &mt7530_regmap_bus, priv->bus,
+					  mt7531_pcs_config[i]);
+		if (IS_ERR(regmap)) {
+			ret = PTR_ERR(regmap);
+			break;
+		}
+		pcs = mtk_pcs_lynxi_create(priv->dev, regmap,
+					   MT7531_PHYA_CTRL_SIGNAL3, 0);
+		if (!pcs) {
+			ret = -ENXIO;
+			break;
+		}
+		priv->ports[5 + i].sgmii_pcs = pcs;
+	}
+
+	if (ret && i)
+		mtk_pcs_lynxi_destroy(priv->ports[5].sgmii_pcs);
+
+	return ret;
+}
+
+static const struct of_device_id mt7530_of_match[] = {
+	{ .compatible = "mediatek,mt7621", .data = &mt753x_table[ID_MT7621], },
+	{ .compatible = "mediatek,mt7530", .data = &mt753x_table[ID_MT7530], },
+	{ .compatible = "mediatek,mt7531", .data = &mt753x_table[ID_MT7531], },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, mt7530_of_match);
+
+static int
+mt7530_probe(struct mdio_device *mdiodev)
+{
+	static struct regmap_config *regmap_config;
+	struct mt7530_priv *priv;
+	struct device_node *dn;
+	int ret;
+
+	dn = mdiodev->dev.of_node;
+
+	priv = devm_kzalloc(&mdiodev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->bus = mdiodev->bus;
+	priv->dev = &mdiodev->dev;
+
+	ret = mt7530_probe_common(priv);
+	if (ret)
+		return ret;
+
+	/* Use medatek,mcm property to distinguish hardware type that would
+	 * cause a little bit differences on power-on sequence.
+	 * Not MCM that indicates switch works as the remote standalone
+	 * integrated circuit so the GPIO pin would be used to complete
+	 * the reset, otherwise memory-mapped register accessing used
+	 * through syscon provides in the case of MCM.
+	 */
+	priv->mcm = of_property_read_bool(dn, "mediatek,mcm");
+	if (priv->mcm) {
+		dev_info(&mdiodev->dev, "MT7530 adapts as multi-chip module\n");
+
+		priv->rstc = devm_reset_control_get(&mdiodev->dev, "mcm");
+		if (IS_ERR(priv->rstc)) {
+			dev_err(&mdiodev->dev, "Couldn't get our reset line\n");
+			return PTR_ERR(priv->rstc);
+		}
+	} else {
+		priv->reset = devm_gpiod_get_optional(&mdiodev->dev, "reset",
+						      GPIOD_OUT_LOW);
+		if (IS_ERR(priv->reset)) {
+			dev_err(&mdiodev->dev, "Couldn't get our reset line\n");
+			return PTR_ERR(priv->reset);
+		}
+	}
+
+	if (priv->id == ID_MT7530) {
+		priv->core_pwr = devm_regulator_get(&mdiodev->dev, "core");
+		if (IS_ERR(priv->core_pwr))
+			return PTR_ERR(priv->core_pwr);
+
+		priv->io_pwr = devm_regulator_get(&mdiodev->dev, "io");
+		if (IS_ERR(priv->io_pwr))
+			return PTR_ERR(priv->io_pwr);
+	}
+
+	regmap_config = devm_kzalloc(&mdiodev->dev, sizeof(*regmap_config),
+				     GFP_KERNEL);
+	if (!regmap_config)
+		return -ENOMEM;
+
+	regmap_config->reg_bits = 16;
+	regmap_config->val_bits = 32;
+	regmap_config->reg_stride = 4;
+	regmap_config->max_register = MT7530_CREV;
+	regmap_config->disable_locking = true;
+	priv->regmap = devm_regmap_init(priv->dev, &mt7530_regmap_bus,
+					priv->bus, regmap_config);
+	if (IS_ERR(priv->regmap))
+		return PTR_ERR(priv->regmap);
+
+	if (priv->id == ID_MT7531) {
+		ret = mt7531_create_sgmii(priv);
+		if (ret)
+			return ret;
+	}
+
+	return dsa_register_switch(priv->ds);
+}
+
+static void
+mt7530_remove(struct mdio_device *mdiodev)
+{
+	struct mt7530_priv *priv = dev_get_drvdata(&mdiodev->dev);
+	int ret = 0, i;
+
+	if (!priv)
+		return;
+
+	ret = regulator_disable(priv->core_pwr);
+	if (ret < 0)
+		dev_err(priv->dev,
+			"Failed to disable core power: %d\n", ret);
+
+	ret = regulator_disable(priv->io_pwr);
+	if (ret < 0)
+		dev_err(priv->dev, "Failed to disable io pwr: %d\n",
+			ret);
+
+	mt7530_remove_common(priv);
+
+	for (i = 0; i < 2; ++i)
+		mtk_pcs_lynxi_destroy(priv->ports[5 + i].sgmii_pcs);
+}
+
+static void mt7530_shutdown(struct mdio_device *mdiodev)
+{
+	struct mt7530_priv *priv = dev_get_drvdata(&mdiodev->dev);
+
+	if (!priv)
+		return;
+
+	dsa_switch_shutdown(priv->ds);
+
+	dev_set_drvdata(&mdiodev->dev, NULL);
+}
+
+static struct mdio_driver mt7530_mdio_driver = {
+	.probe  = mt7530_probe,
+	.remove = mt7530_remove,
+	.shutdown = mt7530_shutdown,
+	.mdiodrv.driver = {
+		.name = "mt7530-mdio",
+		.of_match_table = mt7530_of_match,
+	},
+};
+
+mdio_module_driver(mt7530_mdio_driver);
+
+MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
+MODULE_DESCRIPTION("Driver for Mediatek MT7530 Switch (MDIO)");
+MODULE_LICENSE("GPL");