drivers/net/ti/cpsw_mdio.c - platform/external/u-boot - Gitiles

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * CPSW MDIO generic driver for TI AMxx/K2x/EMAC devices.
  *
  * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
  */

 #include <common.h>
 #include <log.h>
 #include <malloc.h>
 #include <asm/io.h>
 #include <miiphy.h>
 #include <wait_bit.h>
 #include <linux/bitops.h>
 #include <linux/delay.h>

 struct cpsw_mdio_regs {
 	u32	version;
 	u32	control;
 #define CONTROL_IDLE		BIT(31)
 #define CONTROL_ENABLE		BIT(30)
 #define CONTROL_FAULT		BIT(19)
 #define CONTROL_FAULT_ENABLE	BIT(18)
 #define CONTROL_DIV_MASK	GENMASK(15, 0)

 #define MDIO_MAN_MDCLK_O        BIT(2)
 #define MDIO_MAN_OE             BIT(1)
 #define MDIO_MAN_PIN            BIT(0)
 #define MDIO_MANUALMODE         BIT(31)

 	u32	alive;
 	u32	link;
 	u32	linkintraw;
 	u32	linkintmasked;
 	u32	__reserved_0[2];
 	u32	userintraw;
 	u32	userintmasked;
 	u32	userintmaskset;
 	u32	userintmaskclr;
 	u32	manualif;
 	u32	poll;
 	u32	__reserved_1[18];

 	struct {
 		u32		access;
 		u32		physel;
 #define USERACCESS_GO		BIT(31)
 #define USERACCESS_WRITE	BIT(30)
 #define USERACCESS_ACK		BIT(29)
 #define USERACCESS_READ		(0)
 #define USERACCESS_PHY_REG_SHIFT	(21)
 #define USERACCESS_PHY_ADDR_SHIFT	(16)
 #define USERACCESS_DATA		GENMASK(15, 0)
 	} user[2];
 };

 #define CPSW_MDIO_DIV_DEF	0xff
 #define PHY_REG_MASK		0x1f
 #define PHY_ID_MASK		0x1f

 #define MDIO_BITRANGE           0x8000
 #define C22_READ_PATTERN        0x6
 #define C22_WRITE_PATTERN       0x5
 #define C22_BITRANGE            0x8
 #define PHY_BITRANGE            0x10
 #define PHY_DATA_BITRANGE       0x8000

 /*
  * This timeout definition is a worst-case ultra defensive measure against
  * unexpected controller lock ups.  Ideally, we should never ever hit this
  * scenario in practice.
  */
 #define CPSW_MDIO_TIMEOUT            100 /* msecs */

 enum cpsw_mdio_manual {
 	MDIO_PIN = 0,
 	MDIO_OE,
 	MDIO_MDCLK,
 };

 struct cpsw_mdio {
 	struct cpsw_mdio_regs *regs;
 	struct mii_dev *bus;
 	int div;
 };

 static void cpsw_mdio_disable(struct cpsw_mdio *mdio)
 {
 	u32 reg;
 	/* Disable MDIO state machine */
 	reg = readl(&mdio->regs->control);
 	reg &= ~CONTROL_ENABLE;

 	writel(reg, &mdio->regs->control);
 }

 static void cpsw_mdio_enable_manual_mode(struct cpsw_mdio *mdio)
 {
 	u32 reg;

 	/* set manual mode */
 	reg = readl(&mdio->regs->poll);
 	reg |= MDIO_MANUALMODE;

 	writel(reg, &mdio->regs->poll);
 }

 static void cpsw_mdio_sw_set_bit(struct cpsw_mdio *mdio,
 				 enum cpsw_mdio_manual bit)
 {
 	u32 reg;

 	reg = readl(&mdio->regs->manualif);

 	switch (bit) {
 	case MDIO_OE:
 		reg |= MDIO_MAN_OE;
 		writel(reg, &mdio->regs->manualif);
 		break;
 	case MDIO_PIN:
 		reg |= MDIO_MAN_PIN;
 		writel(reg, &mdio->regs->manualif);
 		break;
 	case MDIO_MDCLK:
 		reg |= MDIO_MAN_MDCLK_O;
 		writel(reg, &mdio->regs->manualif);
 		break;
 	default:
 		break;
 	};
 }

 static void cpsw_mdio_sw_clr_bit(struct cpsw_mdio *mdio,
 				 enum cpsw_mdio_manual bit)
 {
 	u32 reg;

 	reg = readl(&mdio->regs->manualif);

 	switch (bit) {
 	case MDIO_OE:
 		reg &= ~MDIO_MAN_OE;
 		writel(reg, &mdio->regs->manualif);
 		break;
 	case MDIO_PIN:
 		reg &= ~MDIO_MAN_PIN;
 		writel(reg, &mdio->regs->manualif);
 		break;
 	case MDIO_MDCLK:
 		reg = readl(&mdio->regs->manualif);
 		reg &= ~MDIO_MAN_MDCLK_O;
 		writel(reg, &mdio->regs->manualif);
 		break;
 	default:
 		break;
 	};
 }

 static int cpsw_mdio_test_man_bit(struct cpsw_mdio *mdio,
 				  enum cpsw_mdio_manual bit)
 {
 	u32 reg;

 	reg = readl(&mdio->regs->manualif);
 	return test_bit(bit, &reg);
 }

 static void cpsw_mdio_toggle_man_bit(struct cpsw_mdio *mdio,
 				     enum cpsw_mdio_manual bit)
 {
 	cpsw_mdio_sw_clr_bit(mdio, bit);
 	cpsw_mdio_sw_set_bit(mdio, bit);
 }

 static void cpsw_mdio_man_send_pattern(struct cpsw_mdio *mdio,
 				       u32 bitrange, u32 val)
 {
 	u32 i;

 	for (i = bitrange; i; i = i >> 1) {
 		if (i & val)
 			cpsw_mdio_sw_set_bit(mdio, MDIO_PIN);
 		else
 			cpsw_mdio_sw_clr_bit(mdio, MDIO_PIN);

 		cpsw_mdio_toggle_man_bit(mdio, MDIO_MDCLK);
 	}
 }

 static void cpsw_mdio_sw_preamble(struct cpsw_mdio *mdio)
 {
 	u32 i;

 	cpsw_mdio_sw_clr_bit(mdio, MDIO_OE);

 	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
 	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
 	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
 	cpsw_mdio_sw_set_bit(mdio, MDIO_MDCLK);

 	for (i = 0; i < 32; i++) {
 		cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
 		cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
 		cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
 		cpsw_mdio_toggle_man_bit(mdio, MDIO_MDCLK);
 	}
 }

 static int cpsw_mdio_sw_read(struct mii_dev *bus, int phy_id,
 			     int dev_addr, int phy_reg)
 {
 	struct cpsw_mdio *mdio = bus->priv;
 	u32 reg, i;
 	u8 ack;

 	if (phy_reg & ~PHY_REG_MASK || phy_id & ~PHY_ID_MASK)
 		return -EINVAL;

 	cpsw_mdio_disable(mdio);
 	cpsw_mdio_enable_manual_mode(mdio);
 	cpsw_mdio_sw_preamble(mdio);

 	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
 	cpsw_mdio_sw_set_bit(mdio, MDIO_OE);

 	/* Issue clause 22 MII read function {0,1,1,0} */
 	cpsw_mdio_man_send_pattern(mdio, C22_BITRANGE, C22_READ_PATTERN);

 	/* Send the device number MSB first */
 	cpsw_mdio_man_send_pattern(mdio, PHY_BITRANGE, phy_id);

 	/* Send the register number MSB first */
 	cpsw_mdio_man_send_pattern(mdio, PHY_BITRANGE, phy_reg);

 	/* Send turn around cycles */
 	cpsw_mdio_sw_clr_bit(mdio, MDIO_OE);

 	cpsw_mdio_toggle_man_bit(mdio, MDIO_MDCLK);

 	ack = cpsw_mdio_test_man_bit(mdio, MDIO_PIN);
 	cpsw_mdio_toggle_man_bit(mdio, MDIO_MDCLK);

 	reg = 0;
 	if (ack == 0) {
 		for (i = MDIO_BITRANGE; i; i = i >> 1) {
 			if (cpsw_mdio_test_man_bit(mdio, MDIO_PIN))
 				reg |= i;

 			cpsw_mdio_toggle_man_bit(mdio, MDIO_MDCLK);
 		}
 	} else {
 		for (i = MDIO_BITRANGE; i; i = i >> 1)
 			cpsw_mdio_toggle_man_bit(mdio, MDIO_MDCLK);

 		reg = 0xFFFF;
 	}

 	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
 	cpsw_mdio_sw_set_bit(mdio, MDIO_MDCLK);
 	cpsw_mdio_sw_set_bit(mdio, MDIO_MDCLK);
 	cpsw_mdio_toggle_man_bit(mdio, MDIO_MDCLK);

 	return reg;
 }

 static int cpsw_mdio_sw_write(struct mii_dev *bus, int phy_id,
 			      int dev_addr, int phy_reg, u16 phy_data)
 {
 	struct cpsw_mdio *mdio = bus->priv;

 	if ((phy_reg & ~PHY_REG_MASK) || (phy_id & ~PHY_ID_MASK))
 		return -EINVAL;

 	cpsw_mdio_disable(mdio);
 	cpsw_mdio_enable_manual_mode(mdio);
 	cpsw_mdio_sw_preamble(mdio);

 	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
 	cpsw_mdio_sw_set_bit(mdio, MDIO_OE);

 	/* Issue clause 22 MII write function {0,1,0,1} */
 	cpsw_mdio_man_send_pattern(mdio, C22_BITRANGE, C22_WRITE_PATTERN);

 	/* Send the device number MSB first */
 	cpsw_mdio_man_send_pattern(mdio, PHY_BITRANGE, phy_id);

 	/* Send the register number MSB first */
 	cpsw_mdio_man_send_pattern(mdio, PHY_BITRANGE, phy_reg);

 	/* set turn-around cycles */
 	cpsw_mdio_sw_set_bit(mdio, MDIO_PIN);
 	cpsw_mdio_toggle_man_bit(mdio, MDIO_MDCLK);
 	cpsw_mdio_sw_clr_bit(mdio, MDIO_PIN);
 	cpsw_mdio_toggle_man_bit(mdio, MDIO_MDCLK);

 	/* Send Register data MSB first */
 	cpsw_mdio_man_send_pattern(mdio, PHY_DATA_BITRANGE, phy_data);
 	cpsw_mdio_sw_clr_bit(mdio, MDIO_OE);

 	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
 	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
 	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
 	cpsw_mdio_toggle_man_bit(mdio, MDIO_MDCLK);

 	return 0;
 }

 /* wait until hardware is ready for another user access */
 static int cpsw_mdio_wait_for_user_access(struct cpsw_mdio *mdio)
 {
 	return wait_for_bit_le32(&mdio->regs->user[0].access,
 				 USERACCESS_GO, false,
 				 CPSW_MDIO_TIMEOUT, false);
 }

 static int cpsw_mdio_read(struct mii_dev *bus, int phy_id,
 			  int dev_addr, int phy_reg)
 {
 	struct cpsw_mdio *mdio = bus->priv;
 	int data, ret;
 	u32 reg;

 	if (phy_reg & ~PHY_REG_MASK || phy_id & ~PHY_ID_MASK)
 		return -EINVAL;

 	ret = cpsw_mdio_wait_for_user_access(mdio);
 	if (ret)
 		return ret;
 	reg = (USERACCESS_GO | USERACCESS_READ |
 	       (phy_reg << USERACCESS_PHY_REG_SHIFT) |
 	       (phy_id << USERACCESS_PHY_ADDR_SHIFT));
 	writel(reg, &mdio->regs->user[0].access);
 	ret = cpsw_mdio_wait_for_user_access(mdio);
 	if (ret)
 		return ret;

 	reg = readl(&mdio->regs->user[0].access);
 	data = (reg & USERACCESS_ACK) ? (reg & USERACCESS_DATA) : -1;
 	return data;
 }

 static int cpsw_mdio_write(struct mii_dev *bus, int phy_id, int dev_addr,
 			   int phy_reg, u16 data)
 {
 	struct cpsw_mdio *mdio = bus->priv;
 	u32 reg;
 	int ret;

 	if (phy_reg & ~PHY_REG_MASK || phy_id & ~PHY_ID_MASK)
 		return -EINVAL;

 	ret = cpsw_mdio_wait_for_user_access(mdio);
 	if (ret)
 		return ret;
 	reg = (USERACCESS_GO | USERACCESS_WRITE |
 	       (phy_reg << USERACCESS_PHY_REG_SHIFT) |
 	       (phy_id << USERACCESS_PHY_ADDR_SHIFT) |
 	       (data & USERACCESS_DATA));
 	writel(reg, &mdio->regs->user[0].access);

 	return cpsw_mdio_wait_for_user_access(mdio);
 }

 u32 cpsw_mdio_get_alive(struct mii_dev *bus)
 {
 	struct cpsw_mdio *mdio = bus->priv;
 	u32 val;

 	val = readl(&mdio->regs->alive);
 	return val & GENMASK(7, 0);
 }

 struct mii_dev *cpsw_mdio_init(const char *name, phys_addr_t mdio_base,
 			       u32 bus_freq, int fck_freq, bool manual_mode)
 {
 	struct cpsw_mdio *cpsw_mdio;
 	int ret;

 	cpsw_mdio = calloc(1, sizeof(*cpsw_mdio));
 	if (!cpsw_mdio) {
 		debug("failed to alloc cpsw_mdio\n");
 		return NULL;
 	}

 	cpsw_mdio->bus = mdio_alloc();
 	if (!cpsw_mdio->bus) {
 		debug("failed to alloc mii bus\n");
 		free(cpsw_mdio);
 		return NULL;
 	}

 	cpsw_mdio->regs = (struct cpsw_mdio_regs *)(uintptr_t)mdio_base;

 	if (!bus_freq || !fck_freq)
 		cpsw_mdio->div = CPSW_MDIO_DIV_DEF;
 	else
 		cpsw_mdio->div = (fck_freq / bus_freq) - 1;
 	cpsw_mdio->div &= CONTROL_DIV_MASK;

 	/* set enable and clock divider */
 	writel(cpsw_mdio->div | CONTROL_ENABLE | CONTROL_FAULT |
 	       CONTROL_FAULT_ENABLE, &cpsw_mdio->regs->control);
 	wait_for_bit_le32(&cpsw_mdio->regs->control,
 			  CONTROL_IDLE, false, CPSW_MDIO_TIMEOUT, true);

 	/*
 	 * wait for scan logic to settle:
 	 * the scan time consists of (a) a large fixed component, and (b) a
 	 * small component that varies with the mii bus frequency.  These
 	 * were estimated using measurements at 1.1 and 2.2 MHz on tnetv107x
 	 * silicon.  Since the effect of (b) was found to be largely
 	 * negligible, we keep things simple here.
 	 */
 	mdelay(1);

 	if (manual_mode) {
 		cpsw_mdio->bus->read = cpsw_mdio_sw_read;
 		cpsw_mdio->bus->write = cpsw_mdio_sw_write;
 	} else {
 		cpsw_mdio->bus->read = cpsw_mdio_read;
 		cpsw_mdio->bus->write = cpsw_mdio_write;
 	}

 	cpsw_mdio->bus->priv = cpsw_mdio;
 	snprintf(cpsw_mdio->bus->name, sizeof(cpsw_mdio->bus->name), name);

 	ret = mdio_register(cpsw_mdio->bus);
 	if (ret < 0) {
 		debug("failed to register mii bus\n");
 		goto free_bus;
 	}

 	return cpsw_mdio->bus;

 free_bus:
 	mdio_free(cpsw_mdio->bus);
 	free(cpsw_mdio);
 	return NULL;
 }

 void cpsw_mdio_free(struct mii_dev *bus)
 {
 	struct cpsw_mdio *mdio = bus->priv;
 	u32 reg;

 	/* disable mdio */
 	reg = readl(&mdio->regs->control);
 	reg &= ~CONTROL_ENABLE;
 	writel(reg, &mdio->regs->control);

 	mdio_unregister(bus);
 	mdio_free(bus);
 	free(mdio);
 }
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* CPSW MDIO generic driver for TI AMxx/K2x/EMAC devices.
	*
	* Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
	*/

	#include <common.h>
	#include <log.h>
	#include <malloc.h>
	#include <asm/io.h>
	#include <miiphy.h>
	#include <wait_bit.h>
	#include <linux/bitops.h>
	#include <linux/delay.h>

	struct cpsw_mdio_regs {
	u32 version;
	u32 control;
	#define CONTROL_IDLE BIT(31)
	#define CONTROL_ENABLE BIT(30)
	#define CONTROL_FAULT BIT(19)
	#define CONTROL_FAULT_ENABLE BIT(18)
	#define CONTROL_DIV_MASK GENMASK(15, 0)

	#define MDIO_MAN_MDCLK_O BIT(2)
	#define MDIO_MAN_OE BIT(1)
	#define MDIO_MAN_PIN BIT(0)
	#define MDIO_MANUALMODE BIT(31)

	u32 alive;
	u32 link;
	u32 linkintraw;
	u32 linkintmasked;
	u32 __reserved_0[2];
	u32 userintraw;
	u32 userintmasked;
	u32 userintmaskset;
	u32 userintmaskclr;
	u32 manualif;
	u32 poll;
	u32 __reserved_1[18];

	struct {
	u32 access;
	u32 physel;
	#define USERACCESS_GO BIT(31)
	#define USERACCESS_WRITE BIT(30)
	#define USERACCESS_ACK BIT(29)
	#define USERACCESS_READ (0)
	#define USERACCESS_PHY_REG_SHIFT (21)
	#define USERACCESS_PHY_ADDR_SHIFT (16)
	#define USERACCESS_DATA GENMASK(15, 0)
	} user[2];
	};

	#define CPSW_MDIO_DIV_DEF 0xff
	#define PHY_REG_MASK 0x1f
	#define PHY_ID_MASK 0x1f

	#define MDIO_BITRANGE 0x8000
	#define C22_READ_PATTERN 0x6
	#define C22_WRITE_PATTERN 0x5
	#define C22_BITRANGE 0x8
	#define PHY_BITRANGE 0x10
	#define PHY_DATA_BITRANGE 0x8000

	/*
	* This timeout definition is a worst-case ultra defensive measure against
	* unexpected controller lock ups. Ideally, we should never ever hit this
	* scenario in practice.
	*/
	#define CPSW_MDIO_TIMEOUT 100 /* msecs */

	enum cpsw_mdio_manual {
	MDIO_PIN = 0,
	MDIO_OE,
	MDIO_MDCLK,
	};

	struct cpsw_mdio {
	struct cpsw_mdio_regs *regs;
	struct mii_dev *bus;
	int div;
	};

	static void cpsw_mdio_disable(struct cpsw_mdio *mdio)
	{
	u32 reg;
	/* Disable MDIO state machine */
	reg = readl(&mdio->regs->control);
	reg &= ~CONTROL_ENABLE;

	writel(reg, &mdio->regs->control);
	}

	static void cpsw_mdio_enable_manual_mode(struct cpsw_mdio *mdio)
	{
	u32 reg;

	/* set manual mode */
	reg = readl(&mdio->regs->poll);
	reg \|= MDIO_MANUALMODE;

	writel(reg, &mdio->regs->poll);
	}

	static void cpsw_mdio_sw_set_bit(struct cpsw_mdio *mdio,
	enum cpsw_mdio_manual bit)
	{
	u32 reg;

	reg = readl(&mdio->regs->manualif);

	switch (bit) {
	case MDIO_OE:
	reg \|= MDIO_MAN_OE;
	writel(reg, &mdio->regs->manualif);
	break;
	case MDIO_PIN:
	reg \|= MDIO_MAN_PIN;
	writel(reg, &mdio->regs->manualif);
	break;
	case MDIO_MDCLK:
	reg \|= MDIO_MAN_MDCLK_O;
	writel(reg, &mdio->regs->manualif);
	break;
	default:
	break;
	};
	}

	static void cpsw_mdio_sw_clr_bit(struct cpsw_mdio *mdio,
	enum cpsw_mdio_manual bit)
	{
	u32 reg;

	reg = readl(&mdio->regs->manualif);

	switch (bit) {
	case MDIO_OE:
	reg &= ~MDIO_MAN_OE;
	writel(reg, &mdio->regs->manualif);
	break;
	case MDIO_PIN:
	reg &= ~MDIO_MAN_PIN;
	writel(reg, &mdio->regs->manualif);
	break;
	case MDIO_MDCLK:
	reg = readl(&mdio->regs->manualif);
	reg &= ~MDIO_MAN_MDCLK_O;
	writel(reg, &mdio->regs->manualif);
	break;
	default:
	break;
	};
	}

	static int cpsw_mdio_test_man_bit(struct cpsw_mdio *mdio,
	enum cpsw_mdio_manual bit)
	{
	u32 reg;

	reg = readl(&mdio->regs->manualif);
	return test_bit(bit, &reg);
	}

	static void cpsw_mdio_toggle_man_bit(struct cpsw_mdio *mdio,
	enum cpsw_mdio_manual bit)
	{
	cpsw_mdio_sw_clr_bit(mdio, bit);
	cpsw_mdio_sw_set_bit(mdio, bit);
	}

	static void cpsw_mdio_man_send_pattern(struct cpsw_mdio *mdio,
	u32 bitrange, u32 val)
	{
	u32 i;

	for (i = bitrange; i; i = i >> 1) {
	if (i & val)
	cpsw_mdio_sw_set_bit(mdio, MDIO_PIN);
	else
	cpsw_mdio_sw_clr_bit(mdio, MDIO_PIN);

	cpsw_mdio_toggle_man_bit(mdio, MDIO_MDCLK);
	}
	}

	static void cpsw_mdio_sw_preamble(struct cpsw_mdio *mdio)
	{
	u32 i;

	cpsw_mdio_sw_clr_bit(mdio, MDIO_OE);

	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
	cpsw_mdio_sw_set_bit(mdio, MDIO_MDCLK);

	for (i = 0; i < 32; i++) {
	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
	cpsw_mdio_toggle_man_bit(mdio, MDIO_MDCLK);
	}
	}

	static int cpsw_mdio_sw_read(struct mii_dev *bus, int phy_id,
	int dev_addr, int phy_reg)
	{
	struct cpsw_mdio *mdio = bus->priv;
	u32 reg, i;
	u8 ack;

	if (phy_reg & ~PHY_REG_MASK \|\| phy_id & ~PHY_ID_MASK)
	return -EINVAL;

	cpsw_mdio_disable(mdio);
	cpsw_mdio_enable_manual_mode(mdio);
	cpsw_mdio_sw_preamble(mdio);

	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
	cpsw_mdio_sw_set_bit(mdio, MDIO_OE);

	/* Issue clause 22 MII read function {0,1,1,0} */
	cpsw_mdio_man_send_pattern(mdio, C22_BITRANGE, C22_READ_PATTERN);

	/* Send the device number MSB first */
	cpsw_mdio_man_send_pattern(mdio, PHY_BITRANGE, phy_id);

	/* Send the register number MSB first */
	cpsw_mdio_man_send_pattern(mdio, PHY_BITRANGE, phy_reg);

	/* Send turn around cycles */
	cpsw_mdio_sw_clr_bit(mdio, MDIO_OE);

	cpsw_mdio_toggle_man_bit(mdio, MDIO_MDCLK);

	ack = cpsw_mdio_test_man_bit(mdio, MDIO_PIN);
	cpsw_mdio_toggle_man_bit(mdio, MDIO_MDCLK);

	reg = 0;
	if (ack == 0) {
	for (i = MDIO_BITRANGE; i; i = i >> 1) {
	if (cpsw_mdio_test_man_bit(mdio, MDIO_PIN))
	reg \|= i;

	cpsw_mdio_toggle_man_bit(mdio, MDIO_MDCLK);
	}
	} else {
	for (i = MDIO_BITRANGE; i; i = i >> 1)
	cpsw_mdio_toggle_man_bit(mdio, MDIO_MDCLK);

	reg = 0xFFFF;
	}

	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
	cpsw_mdio_sw_set_bit(mdio, MDIO_MDCLK);
	cpsw_mdio_sw_set_bit(mdio, MDIO_MDCLK);
	cpsw_mdio_toggle_man_bit(mdio, MDIO_MDCLK);

	return reg;
	}

	static int cpsw_mdio_sw_write(struct mii_dev *bus, int phy_id,
	int dev_addr, int phy_reg, u16 phy_data)
	{
	struct cpsw_mdio *mdio = bus->priv;

	if ((phy_reg & ~PHY_REG_MASK) \|\| (phy_id & ~PHY_ID_MASK))
	return -EINVAL;

	cpsw_mdio_disable(mdio);
	cpsw_mdio_enable_manual_mode(mdio);
	cpsw_mdio_sw_preamble(mdio);

	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
	cpsw_mdio_sw_set_bit(mdio, MDIO_OE);

	/* Issue clause 22 MII write function {0,1,0,1} */
	cpsw_mdio_man_send_pattern(mdio, C22_BITRANGE, C22_WRITE_PATTERN);

	/* Send the device number MSB first */
	cpsw_mdio_man_send_pattern(mdio, PHY_BITRANGE, phy_id);

	/* Send the register number MSB first */
	cpsw_mdio_man_send_pattern(mdio, PHY_BITRANGE, phy_reg);

	/* set turn-around cycles */
	cpsw_mdio_sw_set_bit(mdio, MDIO_PIN);
	cpsw_mdio_toggle_man_bit(mdio, MDIO_MDCLK);
	cpsw_mdio_sw_clr_bit(mdio, MDIO_PIN);
	cpsw_mdio_toggle_man_bit(mdio, MDIO_MDCLK);

	/* Send Register data MSB first */
	cpsw_mdio_man_send_pattern(mdio, PHY_DATA_BITRANGE, phy_data);
	cpsw_mdio_sw_clr_bit(mdio, MDIO_OE);

	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
	cpsw_mdio_sw_clr_bit(mdio, MDIO_MDCLK);
	cpsw_mdio_toggle_man_bit(mdio, MDIO_MDCLK);

	return 0;
	}

	/* wait until hardware is ready for another user access */
	static int cpsw_mdio_wait_for_user_access(struct cpsw_mdio *mdio)
	{
	return wait_for_bit_le32(&mdio->regs->user[0].access,
	USERACCESS_GO, false,
	CPSW_MDIO_TIMEOUT, false);
	}

	static int cpsw_mdio_read(struct mii_dev *bus, int phy_id,
	int dev_addr, int phy_reg)
	{
	struct cpsw_mdio *mdio = bus->priv;
	int data, ret;
	u32 reg;

	if (phy_reg & ~PHY_REG_MASK \|\| phy_id & ~PHY_ID_MASK)
	return -EINVAL;

	ret = cpsw_mdio_wait_for_user_access(mdio);
	if (ret)
	return ret;
	reg = (USERACCESS_GO \| USERACCESS_READ \|
	(phy_reg << USERACCESS_PHY_REG_SHIFT) \|
	(phy_id << USERACCESS_PHY_ADDR_SHIFT));
	writel(reg, &mdio->regs->user[0].access);
	ret = cpsw_mdio_wait_for_user_access(mdio);
	if (ret)
	return ret;

	reg = readl(&mdio->regs->user[0].access);
	data = (reg & USERACCESS_ACK) ? (reg & USERACCESS_DATA) : -1;
	return data;
	}

	static int cpsw_mdio_write(struct mii_dev *bus, int phy_id, int dev_addr,
	int phy_reg, u16 data)
	{
	struct cpsw_mdio *mdio = bus->priv;
	u32 reg;
	int ret;

	if (phy_reg & ~PHY_REG_MASK \|\| phy_id & ~PHY_ID_MASK)
	return -EINVAL;

	ret = cpsw_mdio_wait_for_user_access(mdio);
	if (ret)
	return ret;
	reg = (USERACCESS_GO \| USERACCESS_WRITE \|
	(phy_reg << USERACCESS_PHY_REG_SHIFT) \|
	(phy_id << USERACCESS_PHY_ADDR_SHIFT) \|
	(data & USERACCESS_DATA));
	writel(reg, &mdio->regs->user[0].access);

	return cpsw_mdio_wait_for_user_access(mdio);
	}

	u32 cpsw_mdio_get_alive(struct mii_dev *bus)
	{
	struct cpsw_mdio *mdio = bus->priv;
	u32 val;

	val = readl(&mdio->regs->alive);
	return val & GENMASK(7, 0);
	}

	struct mii_dev cpsw_mdio_init(const char name, phys_addr_t mdio_base,
	u32 bus_freq, int fck_freq, bool manual_mode)
	{
	struct cpsw_mdio *cpsw_mdio;
	int ret;

	cpsw_mdio = calloc(1, sizeof(*cpsw_mdio));
	if (!cpsw_mdio) {
	debug("failed to alloc cpsw_mdio\n");
	return NULL;
	}

	cpsw_mdio->bus = mdio_alloc();
	if (!cpsw_mdio->bus) {
	debug("failed to alloc mii bus\n");
	free(cpsw_mdio);
	return NULL;
	}

	cpsw_mdio->regs = (struct cpsw_mdio_regs *)(uintptr_t)mdio_base;

	if (!bus_freq \|\| !fck_freq)
	cpsw_mdio->div = CPSW_MDIO_DIV_DEF;
	else
	cpsw_mdio->div = (fck_freq / bus_freq) - 1;
	cpsw_mdio->div &= CONTROL_DIV_MASK;

	/* set enable and clock divider */
	writel(cpsw_mdio->div \| CONTROL_ENABLE \| CONTROL_FAULT \|
	CONTROL_FAULT_ENABLE, &cpsw_mdio->regs->control);
	wait_for_bit_le32(&cpsw_mdio->regs->control,
	CONTROL_IDLE, false, CPSW_MDIO_TIMEOUT, true);

	/*
	* wait for scan logic to settle:
	* the scan time consists of (a) a large fixed component, and (b) a
	* small component that varies with the mii bus frequency. These
	* were estimated using measurements at 1.1 and 2.2 MHz on tnetv107x
	* silicon. Since the effect of (b) was found to be largely
	* negligible, we keep things simple here.
	*/
	mdelay(1);

	if (manual_mode) {
	cpsw_mdio->bus->read = cpsw_mdio_sw_read;
	cpsw_mdio->bus->write = cpsw_mdio_sw_write;
	} else {
	cpsw_mdio->bus->read = cpsw_mdio_read;
	cpsw_mdio->bus->write = cpsw_mdio_write;
	}

	cpsw_mdio->bus->priv = cpsw_mdio;
	snprintf(cpsw_mdio->bus->name, sizeof(cpsw_mdio->bus->name), name);

	ret = mdio_register(cpsw_mdio->bus);
	if (ret < 0) {
	debug("failed to register mii bus\n");
	goto free_bus;
	}

	return cpsw_mdio->bus;

	free_bus:
	mdio_free(cpsw_mdio->bus);
	free(cpsw_mdio);
	return NULL;
	}

	void cpsw_mdio_free(struct mii_dev *bus)
	{
	struct cpsw_mdio *mdio = bus->priv;
	u32 reg;

	/* disable mdio */
	reg = readl(&mdio->regs->control);
	reg &= ~CONTROL_ENABLE;
	writel(reg, &mdio->regs->control);

	mdio_unregister(bus);
	mdio_free(bus);
	free(mdio);
	}