text: // SPDX-License-Identifier: GPL-2.0+
  /*
   * drivers/net/phy/lxt.c
   *
   * Driver for Intel LXT PHYs
   *
   * Author: Andy Fleming
   *
   * Copyright (c) 2004 Freescale Semiconductor, Inc.
   */
  #include <linux/kernel.h>
  #include <linux/string.h>
  #include <linux/errno.h>
  #include <linux/unistd.h>
  #include <linux/interrupt.h>
  #include <linux/init.h>
  #include <linux/delay.h>
  #include <linux/netdevice.h>
  #include <linux/etherdevice.h>
  #include <linux/skbuff.h>
  #include <linux/spinlock.h>
  #include <linux/mm.h>
  #include <linux/module.h>
  #include <linux/mii.h>
  #include <linux/ethtool.h>
  #include <linux/phy.h>
  
  #include <asm/io.h>
  #include <asm/irq.h>
  #include <linux/uaccess.h>
  
  /* The Level one LXT970 is used by many boards				     */
  
  #define MII_LXT970_IER       17  /* Interrupt Enable Register */
  
  #define MII_LXT970_IER_IEN	0x0002
  
  #define MII_LXT970_ISR       18  /* Interrupt Status Register */
  
  #define MII_LXT970_CONFIG    19  /* Configuration Register    */
  
  /* ------------------------------------------------------------------------- */
  /* The Level one LXT971 is used on some of my custom boards                  */
  
  /* register definitions for the 971 */
  #define MII_LXT971_IER		18  /* Interrupt Enable Register */
  #define MII_LXT971_IER_IEN	0x00f2
  
  #define MII_LXT971_ISR		19  /* Interrupt Status Register */
  
  /* register definitions for the 973 */
  #define MII_LXT973_PCR 16 /* Port Configuration Register */
  #define PCR_FIBER_SELECT 1
  
  MODULE_DESCRIPTION("Intel LXT PHY driver");
  MODULE_AUTHOR("Andy Fleming");
  MODULE_LICENSE("GPL");
  
  static int lxt970_ack_interrupt(struct phy_device *phydev)
  {
  	int err;
  
  	err = phy_read(phydev, MII_BMSR);
  
  	if (err < 0)
  		return err;
  
  	err = phy_read(phydev, MII_LXT970_ISR);
  
  	if (err < 0)
  		return err;
  
  	return 0;
  }
  
  static int lxt970_config_intr(struct phy_device *phydev)
  {
  	if (phydev->interrupts == PHY_INTERRUPT_ENABLED)
  		return phy_write(phydev, MII_LXT970_IER, MII_LXT970_IER_IEN);
  	else
  		return phy_write(phydev, MII_LXT970_IER, 0);
  }
  
  static int lxt970_config_init(struct phy_device *phydev)
  {
  	return phy_write(phydev, MII_LXT970_CONFIG, 0);
  }
  
  
  static int lxt971_ack_interrupt(struct phy_device *phydev)
  {
  	int err = phy_read(phydev, MII_LXT971_ISR);
  
  	if (err < 0)
  		return err;
  
  	return 0;
  }
  
  static int lxt971_config_intr(struct phy_device *phydev)
  {
  	if (phydev->interrupts == PHY_INTERRUPT_ENABLED)
  		return phy_write(phydev, MII_LXT971_IER, MII_LXT971_IER_IEN);
  	else
  		return phy_write(phydev, MII_LXT971_IER, 0);
  }
  
  /*
   * A2 version of LXT973 chip has an ERRATA: it randomly return the contents
   * of the previous even register when you read a odd register regularly
   */
  
  static int lxt973a2_update_link(struct phy_device *phydev)
  {
  	int status;
  	int control;
  	int retry = 8; /* we try 8 times */
  
  	/* Do a fake read */
  	status = phy_read(phydev, MII_BMSR);
  
  	if (status < 0)
  		return status;
  
  	control = phy_read(phydev, MII_BMCR);
  	if (control < 0)
  		return control;
  
  	do {
  		/* Read link and autonegotiation status */
  		status = phy_read(phydev, MII_BMSR);
  	} while (status >= 0 && retry-- && status == control);
  
  	if (status < 0)
  		return status;
  
  	if ((status & BMSR_LSTATUS) == 0)
  		phydev->link = 0;
  	else
  		phydev->link = 1;
  
  	return 0;
  }
  
  static int lxt973a2_read_status(struct phy_device *phydev)
  {
  	int adv;
  	int err;
  	int lpa;
  
  	/* Update the link, but return if there was an error */
  	err = lxt973a2_update_link(phydev);
  	if (err)
  		return err;
  
  	if (AUTONEG_ENABLE == phydev->autoneg) {
  		int retry = 1;
  
  		adv = phy_read(phydev, MII_ADVERTISE);
  
  		if (adv < 0)
  			return adv;
  
  		do {
  			lpa = phy_read(phydev, MII_LPA);
  
  			if (lpa < 0)
  				return lpa;
  
  			/* If both registers are equal, it is suspect but not
  			* impossible, hence a new try
  			*/
  		} while (lpa == adv && retry--);
  
  		mii_lpa_to_linkmode_lpa_t(phydev->lp_advertising, lpa);
  
  		lpa &= adv;
  
  		phydev->speed = SPEED_10;
  		phydev->duplex = DUPLEX_HALF;
  		phydev->pause = phydev->asym_pause = 0;
  
  		if (lpa & (LPA_100FULL | LPA_100HALF)) {
  			phydev->speed = SPEED_100;
  
  			if (lpa & LPA_100FULL)
  				phydev->duplex = DUPLEX_FULL;
  		} else {
  			if (lpa & LPA_10FULL)
  				phydev->duplex = DUPLEX_FULL;
  		}
  
  		if (phydev->duplex == DUPLEX_FULL) {
  			phydev->pause = lpa & LPA_PAUSE_CAP ? 1 : 0;
  			phydev->asym_pause = lpa & LPA_PAUSE_ASYM ? 1 : 0;
  		}
  	} else {
  		int bmcr = phy_read(phydev, MII_BMCR);
  
  		if (bmcr < 0)
  			return bmcr;
  
  		if (bmcr & BMCR_FULLDPLX)
  			phydev->duplex = DUPLEX_FULL;
  		else
  			phydev->duplex = DUPLEX_HALF;
  
  		if (bmcr & BMCR_SPEED1000)
  			phydev->speed = SPEED_1000;
  		else if (bmcr & BMCR_SPEED100)
  			phydev->speed = SPEED_100;
  		else
  			phydev->speed = SPEED_10;
  
  		phydev->pause = phydev->asym_pause = 0;
  		linkmode_zero(phydev->lp_advertising);
  	}
  
  	return 0;
  }
  
  static int lxt973_probe(struct phy_device *phydev)
  {
  	int val = phy_read(phydev, MII_LXT973_PCR);
  
  	if (val & PCR_FIBER_SELECT) {
  		/*
  		 * If fiber is selected, then the only correct setting
  		 * is 100Mbps, full duplex, and auto negotiation off.
  		 */
  		val = phy_read(phydev, MII_BMCR);
  		val |= (BMCR_SPEED100 | BMCR_FULLDPLX);
  		val &= ~BMCR_ANENABLE;
  		phy_write(phydev, MII_BMCR, val);
  		/* Remember that the port is in fiber mode. */
  		phydev->priv = lxt973_probe;
  	} else {
  		phydev->priv = NULL;
  	}
  	return 0;
  }
  
  static int lxt973_config_aneg(struct phy_device *phydev)
  {
  	/* Do nothing if port is in fiber mode. */
  	return phydev->priv ? 0 : genphy_config_aneg(phydev);
  }
  
  static struct phy_driver lxt97x_driver[] = {
  {
  	.phy_id		= 0x78100000,
  	.name		= "LXT970",
  	.phy_id_mask	= 0xfffffff0,
  	/* PHY_BASIC_FEATURES */
  	.config_init	= lxt970_config_init,
  	.ack_interrupt	= lxt970_ack_interrupt,
  	.config_intr	= lxt970_config_intr,
  }, {
  	.phy_id		= 0x001378e0,
  	.name		= "LXT971",
  	.phy_id_mask	= 0xfffffff0,
  	/* PHY_BASIC_FEATURES */
  	.ack_interrupt	= lxt971_ack_interrupt,
  	.config_intr	= lxt971_config_intr,
  	.suspend	= genphy_suspend,
  	.resume		= genphy_resume,
  }, {
  	.phy_id		= 0x00137a10,
  	.name		= "LXT973-A2",
  	.phy_id_mask	= 0xffffffff,
  	/* PHY_BASIC_FEATURES */
  	.flags		= 0,
  	.probe		= lxt973_probe,
  	.config_aneg	= lxt973_config_aneg,
  	.read_status	= lxt973a2_read_status,
  	.suspend	= genphy_suspend,
  	.resume		= genphy_resume,
  }, {
  	.phy_id		= 0x00137a10,
  	.name		= "LXT973",
  	.phy_id_mask	= 0xfffffff0,
  	/* PHY_BASIC_FEATURES */
  	.flags		= 0,
  	.probe		= lxt973_probe,
  	.config_aneg	= lxt973_config_aneg,
  	.suspend	= genphy_suspend,
  	.resume		= genphy_resume,
  } };
  
  module_phy_driver(lxt97x_driver);
  
  static struct mdio_device_id __maybe_unused lxt_tbl[] = {
  	{ 0x78100000, 0xfffffff0 },
  	{ 0x001378e0, 0xfffffff0 },
  	{ 0x00137a10, 0xfffffff0 },
  	{ }
  };
  
  MODULE_DEVICE_TABLE(mdio, lxt_tbl);
  