diff mbox series

[RFC,2/2] net: add support for KSZ9477/KSZ9897/KSZ9567 GbE switch

Message ID 1605291955-32038-3-git-send-email-tharvey@gateworks.com
State RFC
Delegated to: Joe Hershberger
Headers show
Series Add DM driver for KSZ9477/KSZ9897/KSZ9567 GbE Switch | expand

Commit Message

Tim Harvey Nov. 13, 2020, 6:25 p.m. UTC
The Microchip KSZ9477/KSZ9897/KSZ9567 7-Port Gigabit Ethernet Switches
support SGMII/RGMII/MII/RMII with register access via SPI or I2C.

This driver currently supports I2C register access but SPI register
access can be easily added at a later time.

This was tested with a KSZ9897S switch with an IMX8MM FEC MAC connected
via RGMII_ID to the cpu port.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
---
 MAINTAINERS               |   5 +
 drivers/net/phy/Kconfig   |  15 ++
 drivers/net/phy/Makefile  |   1 +
 drivers/net/phy/ksz9477.c | 533 ++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 555 insertions(+)
 create mode 100644 drivers/net/phy/ksz9477.c
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 874cf2c..10a12f9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -784,6 +784,11 @@  F:	drivers/sysreset/sysreset_gpio.c
 F:	drivers/watchdog/xilinx_tb_wdt.c
 N:	xilinx
 
+MICROCHIP KSZ9477
+M:	Tim Harvey <tharvey@gateworks.com>
+S:	Maintained
+F:	drivers/net/phy/ksz9477.c
+
 MIPS
 M:	Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
 S:	Maintained
diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 4e1a93b..9567d679 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -2,6 +2,21 @@ 
 config BITBANGMII
 	bool "Bit-banged ethernet MII management channel support"
 
+config KSZ9477_SWITCH
+	bool "Microchip KSZ9477 GbE Switch support"
+	depends on DM_ETH_PHY
+	help
+	  Enable support for the I2C GbE Switches manufactured by Microchip
+	  including the KSZ9477, KSZ9897, KSZ9893, KSZ9567.
+
+if KSZ9477_SWITCH
+
+config KSZ9477_LED_SINGLE_MODE
+	bool "Single-LED mode"
+	default y
+
+endif # KSZ9477_SWITCH
+
 config MV88E6352_SWITCH
 	bool "Marvell 88E6352 switch support"
 
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index 6e72233..68db3b6 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -5,6 +5,7 @@ 
 
 obj-$(CONFIG_BITBANGMII) += miiphybb.o
 obj-$(CONFIG_B53_SWITCH) += b53.o
+obj-$(CONFIG_KSZ9477_SWITCH) += ksz9477.o
 obj-$(CONFIG_MV88E61XX_SWITCH) += mv88e61xx.o
 obj-$(CONFIG_MV88E6352_SWITCH) += mv88e6352.o
 
diff --git a/drivers/net/phy/ksz9477.c b/drivers/net/phy/ksz9477.c
new file mode 100644
index 0000000..dfd1930
--- /dev/null
+++ b/drivers/net/phy/ksz9477.c
@@ -0,0 +1,533 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2020
+ * Tim Harvey, Gateworks Corporation
+ */
+#include <dm.h>
+#include <dm/device_compat.h>
+#include <eth_phy.h>
+#include <linux/delay.h>
+#include <miiphy.h>
+#include <i2c.h>
+
+#include <asm-generic/gpio.h>
+
+#define REG_CHIP_ID0__1			0x0000
+
+/* Port Control */
+#define REG_PORT_XMII_CTRL_1		0x0301
+#define PORT_MII_NOT_1GBIT		BIT(6)
+#define PORT_MII_SEL_EDGE		BIT(5)
+#define PORT_RGMII_ID_IG_ENABLE		BIT(4)
+#define PORT_RGMII_ID_EG_ENABLE		BIT(3)
+#define PORT_MII_MAC_MODE		BIT(2)
+#define PORT_MII_SEL_M			0x3
+#define PORT_RGMII_SEL			0x0
+#define PORT_RMII_SEL			0x1
+#define PORT_GMII_SEL			0x2
+#define PORT_MII_SEL			0x3
+
+/* MMD */
+#define REG_PORT_PHY_MMD_SETUP		0x011A
+#define PORT_MMD_OP_MODE_M		0x3
+#define PORT_MMD_OP_MODE_S		14
+#define PORT_MMD_OP_INDEX		0
+#define PORT_MMD_OP_DATA_NO_INCR	1
+#define PORT_MMD_OP_DATA_INCR_RW	2
+#define PORT_MMD_OP_DATA_INCR_W		3
+#define PORT_MMD_DEVICE_ID_M		0x1F
+#define MMD_SETUP(mode, dev)		(((u16)(mode) << PORT_MMD_OP_MODE_S) | (dev))
+#define REG_PORT_PHY_MMD_INDEX_DATA	0x011C
+
+/* Operation control */
+#define REG_SW_OPERATION		0x0300
+#define SW_RESET			BIT(1)
+#define SW_START			BIT(0)
+
+#define PORT_CTRL_ADDR(port, addr) ((addr) | (((port) + 1) << 12))
+
+struct ksz_phy_priv {
+	struct udevice *dev;
+	struct mii_dev *bus;
+	phy_interface_t interface;
+	int phy_port_cnt;
+	int phy_port_cpu;
+	int phy_ports;
+};
+
+static inline int ksz_read8(struct udevice *dev, u32 reg, u8 *val)
+{
+	int ret = dm_i2c_read(dev, reg, val, 1);
+
+	dev_dbg(dev, "%s 0x%04x<<0x%02x\n", __func__, reg, *val);
+
+	return ret;
+}
+
+static inline int ksz_pread8(struct udevice *dev, int port, int reg, u8 *val)
+{
+	return ksz_read8(dev, PORT_CTRL_ADDR(port, reg), val);
+}
+
+static inline int ksz_write8(struct udevice *dev, u32 reg, u8 val)
+{
+	dev_dbg(dev, "%s 0x%04x>>0x%02x\n", __func__, reg, val);
+	return dm_i2c_write(dev, reg, &val, 1);
+}
+
+static inline int ksz_pwrite8(struct udevice *dev, int port, int reg, u8 val)
+{
+	return ksz_write8(dev, PORT_CTRL_ADDR(port, reg), val);
+}
+
+static inline int ksz_write16(struct udevice *dev, u32 reg, u16 val)
+{
+	u8 buf[2];
+
+	buf[1] = val & 0xff;
+	buf[0] = val >> 8;
+	dev_dbg(dev, "%s 0x%04x>>0x%04x\n", __func__, reg, val);
+
+	return dm_i2c_write(dev, reg, buf, 2);
+}
+
+static inline int ksz_pwrite16(struct udevice *dev, int port, int reg, u16 val)
+{
+	return ksz_write16(dev, PORT_CTRL_ADDR(port, reg), val);
+}
+
+static inline int ksz_read16(struct udevice *dev, u32 reg, u16 *val)
+{
+	u8 buf[2];
+	int ret;
+
+	ret = dm_i2c_read(dev, reg, buf, 2);
+	*val = (buf[0] << 8) | buf[1];
+	dev_dbg(dev, "%s 0x%04x<<0x%04x\n", __func__, reg, *val);
+
+	return ret;
+}
+
+static inline int ksz_pread16(struct udevice *dev, int port, int reg, u16 *val)
+{
+	return ksz_read16(dev, PORT_CTRL_ADDR(port, reg), val);
+}
+
+static inline int ksz_read32(struct udevice *dev, u32 reg, u32 *val)
+{
+	return dm_i2c_read(dev, reg, (u8 *)val, 4);
+}
+
+static inline int ksz_pread32(struct udevice *dev, int port, int reg, u32 *val)
+{
+	return ksz_read32(dev, PORT_CTRL_ADDR(port, reg), val);
+}
+
+static inline int ksz_write32(struct udevice *dev, u32 reg, u32 val)
+{
+	u8 buf[4];
+
+	buf[3] = val & 0xff;
+	buf[2] = (val >> 24) & 0xff;
+	buf[1] = (val >> 16) & 0xff;
+	buf[0] = (val >> 8) & 0xff;
+	dev_dbg(dev, "%s 0x%04x>>0x%04x\n", __func__, reg, val);
+
+	return dm_i2c_write(dev, reg, buf, 4);
+}
+
+static inline int ksz_pwrite32(struct udevice *dev, int port, int reg, u32 val)
+{
+	return ksz_write32(dev, PORT_CTRL_ADDR(port, reg), val);
+}
+
+static void ksz9477_port_mmd_read(struct udevice *dev, int port, u8 addr, u16 reg, u16 *val)
+{
+	ksz_pwrite16(dev, port, REG_PORT_PHY_MMD_SETUP, MMD_SETUP(PORT_MMD_OP_INDEX, addr));
+	ksz_pwrite16(dev, port, REG_PORT_PHY_MMD_INDEX_DATA, reg);
+	ksz_pwrite16(dev, port, REG_PORT_PHY_MMD_SETUP, MMD_SETUP(PORT_MMD_OP_DATA_NO_INCR, addr));
+	ksz_pread16(dev, port, REG_PORT_PHY_MMD_INDEX_DATA, val);
+	dev_dbg(dev, "%s  P%d 0x%02x:0x%04x<<0x%04x\n", __func__, port + 1, addr, reg, *val);
+}
+
+static void ksz9477_port_mmd_write(struct udevice *dev, int port, u8 addr, u16 reg, u16 val)
+{
+	dev_dbg(dev, "%s P%d 0x%02x:0x%04x>>0x%04x\n", __func__, port + 1, addr, addr, val);
+	ksz_pwrite16(dev, port, REG_PORT_PHY_MMD_SETUP, MMD_SETUP(PORT_MMD_OP_INDEX, addr));
+	ksz_pwrite16(dev, port, REG_PORT_PHY_MMD_INDEX_DATA, addr);
+	ksz_pwrite16(dev, port, REG_PORT_PHY_MMD_SETUP, MMD_SETUP(PORT_MMD_OP_DATA_NO_INCR, addr));
+	ksz_pwrite16(dev, port, REG_PORT_PHY_MMD_INDEX_DATA, val);
+}
+
+/* Apply PHY settings to address errata listed in KSZ9477, KSZ9897, KSZ9896, KSZ9567
+ * Silicon Errata and Data Sheet Clarification documents
+ */
+static void ksz9477_phy_errata_setup(struct udevice *dev, int port)
+{
+	dev_dbg(dev, "%s P%d\n", __func__, port + 1);
+
+	/* Register settings are needed to improve PHY receive performance */
+	ksz9477_port_mmd_write(dev, port, 0x01, 0x6f, 0xdd0b);
+	ksz9477_port_mmd_write(dev, port, 0x01, 0x8f, 0x6032);
+	ksz9477_port_mmd_write(dev, port, 0x01, 0x9d, 0x248c);
+	ksz9477_port_mmd_write(dev, port, 0x01, 0x75, 0x0060);
+	ksz9477_port_mmd_write(dev, port, 0x01, 0xd3, 0x7777);
+	ksz9477_port_mmd_write(dev, port, 0x1c, 0x06, 0x3008);
+	ksz9477_port_mmd_write(dev, port, 0x1c, 0x08, 0x2001);
+
+	/* Transmit waveform amplitude can be improved (1000BASE-T, 100BASE-TX, 10BASE-Te) */
+	ksz9477_port_mmd_write(dev, port, 0x1c, 0x04, 0x00d0);
+
+	/* Energy Efficient Ethernet (EEE) feature select must be manually disabled */
+	ksz9477_port_mmd_write(dev, port, 0x07, 0x3c, 0x0000);
+
+	/* Register settings are required to meet data sheet supply current specifications */
+	ksz9477_port_mmd_write(dev, port, 0x1c, 0x13, 0x6eff);
+	ksz9477_port_mmd_write(dev, port, 0x1c, 0x14, 0xe6ff);
+	ksz9477_port_mmd_write(dev, port, 0x1c, 0x15, 0x6eff);
+	ksz9477_port_mmd_write(dev, port, 0x1c, 0x16, 0xe6ff);
+	ksz9477_port_mmd_write(dev, port, 0x1c, 0x17, 0x00ff);
+	ksz9477_port_mmd_write(dev, port, 0x1c, 0x18, 0x43ff);
+	ksz9477_port_mmd_write(dev, port, 0x1c, 0x19, 0xc3ff);
+	ksz9477_port_mmd_write(dev, port, 0x1c, 0x1a, 0x6fff);
+	ksz9477_port_mmd_write(dev, port, 0x1c, 0x1b, 0x07ff);
+	ksz9477_port_mmd_write(dev, port, 0x1c, 0x1c, 0x0fff);
+	ksz9477_port_mmd_write(dev, port, 0x1c, 0x1d, 0xe7ff);
+	ksz9477_port_mmd_write(dev, port, 0x1c, 0x1e, 0xefff);
+	ksz9477_port_mmd_write(dev, port, 0x1c, 0x20, 0xeeee);
+}
+
+static int ksz9477_port_setup(struct phy_device *phydev, int port, bool cpu_port)
+{
+	struct ksz_phy_priv *priv = (struct ksz_phy_priv *)phydev->bus->priv;
+	struct udevice *dev = priv->dev;
+	u8 data8;
+	u16 data16;
+
+	dev_dbg(dev, "%s P%d %s\n", __func__, port + 1, cpu_port ? "cpu" : "");
+
+	if (port < priv->phy_port_cnt) {
+		/* phy port: config errata and leds */
+		ksz9477_phy_errata_setup(dev, port);
+		ksz9477_port_mmd_read(dev, port, 0x02, 0x00, &data16);
+#if (IS_ENABLED(KSZ9477_LED_SINGLE_MODE))
+		data16 |= BIT(4); // single-led mode
+#else
+		data16 &= ~BIT(4); // tri-color dual led mode (default)
+#endif
+		dev_dbg(dev, "%s setting %s-LED mode\n", __func__,
+			(data16 & BIT(4)) ? "single" : "dual");
+		ksz9477_port_mmd_write(dev, port, 0x02, 0x00, data16);
+	} else {
+		/* cpu port: configure MAC interface mode */
+		ksz_pread8(dev, port, REG_PORT_XMII_CTRL_1, &data8);
+		dev_dbg(dev, "%s P%d cpu interface=%d\n", __func__, port + 1, priv->interface);
+		switch (priv->interface) {
+		case PHY_INTERFACE_MODE_MII:
+			data8 &= ~PORT_MII_SEL_M;
+			data8 |= PORT_MII_SEL;
+			data8 |= PORT_MII_NOT_1GBIT;
+			phydev->speed = SPEED_100;
+			break;
+		case PHY_INTERFACE_MODE_RMII:
+			data8 &= ~PORT_MII_SEL_M;
+			data8 |= PORT_RMII_SEL;
+			data8 |= PORT_MII_NOT_1GBIT;
+			phydev->speed = SPEED_100;
+			break;
+		case PHY_INTERFACE_MODE_GMII:
+			data8 &= ~PORT_MII_SEL_M;
+			data8 |= PORT_GMII_SEL;
+			data8 &= ~PORT_MII_NOT_1GBIT;
+			phydev->speed = SPEED_1000;
+			break;
+		default:
+			data8 &= ~PORT_MII_SEL_M;
+			data8 |= PORT_RGMII_SEL;
+			data8 &= ~PORT_MII_NOT_1GBIT;
+			data8 &= ~PORT_RGMII_ID_IG_ENABLE;
+			data8 &= ~PORT_RGMII_ID_EG_ENABLE;
+			if (priv->interface == PHY_INTERFACE_MODE_RGMII_ID ||
+			    priv->interface == PHY_INTERFACE_MODE_RGMII_RXID)
+				data8 |= PORT_RGMII_ID_IG_ENABLE;
+			if (priv->interface == PHY_INTERFACE_MODE_RGMII_ID ||
+			    priv->interface == PHY_INTERFACE_MODE_RGMII_TXID)
+				data8 |= PORT_RGMII_ID_EG_ENABLE;
+			phydev->speed = SPEED_1000;
+			break;
+		}
+		phydev->duplex = DUPLEX_FULL;
+		phydev->link = 1;
+		ksz_write8(dev, PORT_CTRL_ADDR(port, REG_PORT_XMII_CTRL_1), data8);
+	}
+
+	return 0;
+}
+
+static int ksz9477_phy_mii_read(struct mii_dev *bus, int dev, int addr, int reg)
+{
+	struct ksz_phy_priv *priv = (struct ksz_phy_priv *)bus->priv;
+	u16 val = 0xffff;
+	int port = dev;
+
+	ksz_pread16(priv->dev, port, 0x100 + (reg << 1), &val);
+	dev_dbg(priv->dev, "%s dev=%d addr=0x%x P%d reg=0x%04x:0x%04x<<0x%04x\n", __func__,
+		dev, addr, port + 1, reg, 0x100 + (reg << 1), val);
+
+	return val;
+}
+
+static int ksz9477_phy_mii_write(struct mii_dev *bus, int dev, int addr, int reg, u16 data)
+{
+	struct ksz_phy_priv *priv = (struct ksz_phy_priv *)bus->priv;
+	int port = dev;
+
+	dev_dbg(priv->dev, "%s dev=%d addr=0x%x P%d reg=0x%04x:%04x>>0x%04x\n", __func__,
+		dev, addr, port + 1, reg, 0x100 + (reg << 1), data);
+	ksz_pwrite16(priv->dev, port, 0x100 + (reg << 1), data);
+
+	return 0;
+}
+
+static int ksz9477_phy_config(struct phy_device *phydev)
+{
+	struct ksz_phy_priv *priv = (struct ksz_phy_priv *)phydev->bus->priv;
+	int i;
+	u8 data8;
+	int ret;
+
+	dev_dbg(priv->dev, "%s\n", __func__);
+	ret = ksz9477_port_setup(phydev, priv->phy_port_cpu, true);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < priv->phy_port_cnt; i++) {
+		if ((1 << i) & priv->phy_ports) {
+			phydev->addr = i;
+
+			if (i == priv->phy_port_cpu)
+				continue;
+			ret = ksz9477_port_setup(phydev, i, false);
+			if (ret)
+				return ret;
+
+			ret = phy_reset(phydev);
+			if (ret) {
+				printf("Error resetting P%d PHY %d\n", i + 1, ret);
+				continue;
+			}
+			ret = genphy_config_aneg(phydev);
+			if (ret) {
+				printf("Error setting P%d autoneg: %d\n", i + 1, ret);
+				return ret;
+			}
+		}
+	}
+
+	/* start switch */
+	ksz_read8(priv->dev, REG_SW_OPERATION, &data8);
+	data8 |= SW_START;
+	ksz_write8(priv->dev, REG_SW_OPERATION, data8);
+
+	return 0;
+}
+
+static int ksz9477_phy_startup(struct phy_device *phydev)
+{
+	struct ksz_phy_priv *priv = (struct ksz_phy_priv *)phydev->bus->priv;
+	int i;
+	int link = 0;
+	int speed = phydev->speed;
+	int duplex = phydev->duplex;
+	int ret;
+
+	dev_dbg(priv->dev, "%s\n", __func__);
+	for (i = 0; i < priv->phy_port_cnt; i++) {
+		if ((1 << i) & priv->phy_ports) {
+			phydev->addr = i;
+			/* skip if not linked to avoid timeout waiting for aneg */
+			if (!(ksz9477_phy_mii_read(phydev->bus, i, 0, MII_BMSR) & BMSR_LSTATUS))
+				continue;
+			ret = genphy_update_link(phydev);
+			if (ret < 0)
+				continue;
+			ret = genphy_parse_link(phydev);
+			if (ret < 0)
+				continue;
+			dev_dbg(priv->dev, "%s P%d link=%d speed=%d duplex=%d\n", __func__,
+				i + 1, phydev->link, phydev->speed, phydev->duplex);
+			link = (link || phydev->link);
+		}
+	}
+	phydev->link = link;
+
+	/* Restore CPU interface speed and duplex after it was changed for other ports */
+	phydev->speed = speed;
+	phydev->duplex = duplex;
+	dev_dbg(priv->dev, "%s link=%d speed=%d duplex=%d\n", __func__, link, speed, duplex);
+
+	return 0;
+}
+
+static struct phy_driver ksz9477_phy_driver = {
+	.name = "ksz9477-phy",
+	.uid = 0x00221631,
+	.mask = 0xffffff00,
+	.features = PHY_GBIT_FEATURES,
+	.config = &ksz9477_phy_config,
+	.startup = &ksz9477_phy_startup,
+	.shutdown = &genphy_shutdown,
+};
+
+static int ksz9477_probe(struct udevice *dev)
+{
+	struct ksz_phy_priv *priv = dev_get_priv(dev);
+	ofnode ports_node, port_node;
+	struct ofnode_phandle_args eth_phandle;
+	const char *phy_mode, *label;
+	struct udevice *eth_dev = NULL;
+	struct gpio_desc reset_gpios;
+	u32 reset_assert_us;
+	u32 reset_deassert_us;
+	u32 id;
+	u8 data8;
+	int i, ret;
+
+	dev_dbg(dev, "%s %s\n", __func__, dev->name);
+	ret = i2c_set_chip_offset_len(dev, 2);
+	if (ret) {
+		printf("i2c_set_chip_offset_len failed: %d\n", ret);
+		return ret;
+	}
+
+	/* default config */
+	priv->dev = dev;
+	priv->phy_port_cnt = 5;
+	priv->interface = PHY_INTERFACE_MODE_NONE;
+
+	/* get port config from dt */
+	if (IS_ENABLED(CONFIG_DM_GPIO)) {
+		gpio_request_by_name(dev, "reset-gpios", 0, &reset_gpios, GPIOD_IS_OUT);
+		reset_assert_us = dev_read_u32_default(dev, "reset-assert-us", 0);
+		reset_deassert_us = dev_read_u32_default(dev, "reset-deassert-us", 0);
+		if (dm_gpio_is_valid(&reset_gpios)) {
+			dm_gpio_set_value(&reset_gpios, 1);
+			udelay(reset_assert_us);
+			dm_gpio_set_value(&reset_gpios, 0);
+			udelay(reset_deassert_us);
+		}
+	}
+	ports_node = ofnode_find_subnode(dev_ofnode(dev), "ports");
+	if (!ofnode_valid(ports_node)) {
+		dev_err(dev, "no ports defined\n");
+		return -EINVAL;
+	}
+	ofnode_for_each_subnode(port_node, ports_node) {
+		i = ofnode_read_u32_default(port_node, "reg", -1);
+		ret = ofnode_parse_phandle_with_args(port_node, "ethernet", NULL,
+						     0, 0, &eth_phandle);
+		if (!ret) {
+			priv->phy_port_cpu = i;
+			uclass_get_device_by_ofnode(UCLASS_ETH, eth_phandle.node, &eth_dev);
+		} else {
+			priv->phy_ports |= (1 << i);
+		}
+		label = ofnode_read_string(port_node, "label");
+		phy_mode = ofnode_read_string(port_node, "phy-mode");
+		priv->interface = phy_get_interface_by_name(phy_mode);
+		dev_dbg(dev, "%s:P%d %s %s\n", ofnode_get_name(port_node),
+			i, label, phy_mode ? phy_mode : "");
+	}
+	if (!priv->phy_port_cpu) {
+		dev_err(dev, "no cpu port defined\n");
+		return -EINVAL;
+	}
+	if (!eth_dev) {
+		dev_err(dev, "no ethernet device defined\n");
+		return -EINVAL;
+	}
+	if (!priv->phy_ports) {
+		dev_err(dev, "no phy ports defined\n");
+		return -EINVAL;
+	}
+	switch (priv->interface) {
+	case PHY_INTERFACE_MODE_MII:
+	case PHY_INTERFACE_MODE_RMII:
+	case PHY_INTERFACE_MODE_GMII:
+	case PHY_INTERFACE_MODE_RGMII_RXID:
+	case PHY_INTERFACE_MODE_RGMII_TXID:
+	case PHY_INTERFACE_MODE_RGMII_ID:
+		break;
+	default:
+		dev_err(dev, "invalid phy_mode\n");
+		return -EINVAL;
+	}
+	dev_dbg(dev, "%s:cpu:P%d ports:0x%x eth_dev:%s\n", __func__,
+		priv->phy_port_cpu + 1, priv->phy_ports, eth_dev->name);
+
+	/* chip level reset */
+	ksz_read8(priv->dev, REG_SW_OPERATION, &data8);
+	data8 |= SW_RESET;
+	ksz_write8(priv->dev, REG_SW_OPERATION, data8);
+
+	/* read chip id */
+	ret = ksz_read32(dev, REG_CHIP_ID0__1, &id);
+	if (ret)
+		return ret;
+	id = __swab32(id);
+	dev_dbg(dev, "%s id=0x%08x\n", __func__, id);
+	switch (id & 0xffffff00) {
+	case 0x00947700:
+		puts("Microchip KSZ9477S");
+		break;
+	case 0x00956700:
+		puts("Microchip KSZ9567R");
+		break;
+	case 0x00989700:
+		puts("Microchip KSZ9897S");
+		break;
+	default:
+		dev_err(dev, "invalid chip id: 0x%08x\n", id);
+		return -EINVAL;
+	}
+
+	/* register an mii_bus to translate phy read/write to the various ports */
+	priv->bus = mdio_alloc();
+	if (!priv->bus) {
+		printf("mdio_alloc failed\n");
+		return -ENOMEM;
+	}
+	priv->bus->read = ksz9477_phy_mii_read;
+	priv->bus->write = ksz9477_phy_mii_write;
+	priv->bus->priv = dev->priv;
+	sprintf(priv->bus->name, "%s-mii", dev->name);
+	ret = mdio_register(priv->bus);
+	if (ret) {
+		printf("mdio_register failed\n");
+		free(priv->bus);
+		return ret;
+	}
+
+	/* bind the mdio_bus to our dev */
+	eth_phy_set_mdio_bus(dev, priv->bus);
+
+	phy_register(&ksz9477_phy_driver);
+
+	return 0;
+};
+
+static const struct udevice_id ksz9477_i2creg_ids[] = {
+	{ .compatible = "microchip,ksz9897" },
+	{ .compatible = "microchip,ksz9477" },
+	{ .compatible = "microchip,ksz9567" },
+	{ }
+};
+
+U_BOOT_DRIVER(ksz9477) = {
+	.name		= "ksz9477",
+	.id		= UCLASS_ETH_PHY,
+	.of_match	= ksz9477_i2creg_ids,
+	.probe		= ksz9477_probe,
+	.priv_auto_alloc_size = sizeof(struct ksz_phy_priv),
+};
+