/*
   * mdio.c: Generic support for MDIO-compatible transceivers
   * Copyright 2006-2009 Solarflare Communications Inc.
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 as published
   * by the Free Software Foundation, incorporated herein by reference.
   */
  
  #include <linux/kernel.h>
  #include <linux/capability.h>
  #include <linux/errno.h>
  #include <linux/ethtool.h>
  #include <linux/mdio.h>
  #include <linux/module.h>

  MODULE_DESCRIPTION("Generic support for MDIO-compatible transceivers");
  MODULE_AUTHOR("Copyright 2006-2009 Solarflare Communications Inc.");
  MODULE_LICENSE("GPL");

  /**
   * mdio45_probe - probe for an MDIO (clause 45) device
   * @mdio: MDIO interface
   * @prtad: Expected PHY address
   *
   * This sets @prtad and @mmds in the MDIO interface if successful.
   * Returns 0 on success, negative on error.
   */
  int mdio45_probe(struct mdio_if_info *mdio, int prtad)
  {
  	int mmd, stat2, devs1, devs2;
  
  	/* Assume PHY must have at least one of PMA/PMD, WIS, PCS, PHY
  	 * XS or DTE XS; give up if none is present. */
  	for (mmd = 1; mmd <= 5; mmd++) {
  		/* Is this MMD present? */
  		stat2 = mdio->mdio_read(mdio->dev, prtad, mmd, MDIO_STAT2);
  		if (stat2 < 0 ||
  		    (stat2 & MDIO_STAT2_DEVPRST) != MDIO_STAT2_DEVPRST_VAL)
  			continue;
  
  		/* It should tell us about all the other MMDs */
  		devs1 = mdio->mdio_read(mdio->dev, prtad, mmd, MDIO_DEVS1);
  		devs2 = mdio->mdio_read(mdio->dev, prtad, mmd, MDIO_DEVS2);
  		if (devs1 < 0 || devs2 < 0)
  			continue;
  
  		mdio->prtad = prtad;
  		mdio->mmds = devs1 | (devs2 << 16);
  		return 0;
  	}
  
  	return -ENODEV;
  }
  EXPORT_SYMBOL(mdio45_probe);
  
  /**
   * mdio_set_flag - set or clear flag in an MDIO register
   * @mdio: MDIO interface
   * @prtad: PHY address
   * @devad: MMD address
   * @addr: Register address
   * @mask: Mask for flag (single bit set)
   * @sense: New value of flag
   *
   * This debounces changes: it does not write the register if the flag
   * already has the proper value.  Returns 0 on success, negative on error.
   */
  int mdio_set_flag(const struct mdio_if_info *mdio,
  		  int prtad, int devad, u16 addr, int mask,
  		  bool sense)
  {
  	int old_val = mdio->mdio_read(mdio->dev, prtad, devad, addr);
  	int new_val;
  
  	if (old_val < 0)
  		return old_val;
  	if (sense)
  		new_val = old_val | mask;
  	else
  		new_val = old_val & ~mask;
  	if (old_val == new_val)
  		return 0;
  	return mdio->mdio_write(mdio->dev, prtad, devad, addr, new_val);
  }
  EXPORT_SYMBOL(mdio_set_flag);
  
  /**
   * mdio_link_ok - is link status up/OK
   * @mdio: MDIO interface
   * @mmd_mask: Mask for MMDs to check
   *
   * Returns 1 if the PHY reports link status up/OK, 0 otherwise.
   * @mmd_mask is normally @mdio->mmds, but if loopback is enabled
   * the MMDs being bypassed should be excluded from the mask.
   */
  int mdio45_links_ok(const struct mdio_if_info *mdio, u32 mmd_mask)
  {
  	int devad, reg;
  
  	if (!mmd_mask) {
  		/* Use absence of XGMII faults in lieu of link state */
  		reg = mdio->mdio_read(mdio->dev, mdio->prtad,
  				      MDIO_MMD_PHYXS, MDIO_STAT2);
  		return reg >= 0 && !(reg & MDIO_STAT2_RXFAULT);
  	}
  
  	for (devad = 0; mmd_mask; devad++) {
  		if (mmd_mask & (1 << devad)) {
  			mmd_mask &= ~(1 << devad);

  			/* Reset the latched status and fault flags */

  			mdio->mdio_read(mdio->dev, mdio->prtad,
  					devad, MDIO_STAT1);

  			if (devad == MDIO_MMD_PMAPMD || devad == MDIO_MMD_PCS ||
  			    devad == MDIO_MMD_PHYXS || devad == MDIO_MMD_DTEXS)
  				mdio->mdio_read(mdio->dev, mdio->prtad,
  						devad, MDIO_STAT2);
  
  			/* Check the current status and fault flags */

  			reg = mdio->mdio_read(mdio->dev, mdio->prtad,
  					      devad, MDIO_STAT1);

  			if (reg < 0 ||
  			    (reg & (MDIO_STAT1_FAULT | MDIO_STAT1_LSTATUS)) !=
  			    MDIO_STAT1_LSTATUS)

  				return false;
  		}
  	}
  
  	return true;
  }
  EXPORT_SYMBOL(mdio45_links_ok);
  
  /**
   * mdio45_nway_restart - restart auto-negotiation for this interface
   * @mdio: MDIO interface
   *
   * Returns 0 on success, negative on error.
   */
  int mdio45_nway_restart(const struct mdio_if_info *mdio)
  {
  	if (!(mdio->mmds & MDIO_DEVS_AN))
  		return -EOPNOTSUPP;
  
  	mdio_set_flag(mdio, mdio->prtad, MDIO_MMD_AN, MDIO_CTRL1,
  		      MDIO_AN_CTRL1_RESTART, true);
  	return 0;
  }
  EXPORT_SYMBOL(mdio45_nway_restart);
  
  static u32 mdio45_get_an(const struct mdio_if_info *mdio, u16 addr)
  {
  	u32 result = 0;
  	int reg;
  
  	reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_AN, addr);
  	if (reg & ADVERTISE_10HALF)
  		result |= ADVERTISED_10baseT_Half;
  	if (reg & ADVERTISE_10FULL)
  		result |= ADVERTISED_10baseT_Full;
  	if (reg & ADVERTISE_100HALF)
  		result |= ADVERTISED_100baseT_Half;
  	if (reg & ADVERTISE_100FULL)
  		result |= ADVERTISED_100baseT_Full;

  	if (reg & ADVERTISE_PAUSE_CAP)
  		result |= ADVERTISED_Pause;
  	if (reg & ADVERTISE_PAUSE_ASYM)
  		result |= ADVERTISED_Asym_Pause;

  	return result;
  }
  
  /**
   * mdio45_ethtool_gset_npage - get settings for ETHTOOL_GSET
   * @mdio: MDIO interface
   * @ecmd: Ethtool request structure
   * @npage_adv: Modes currently advertised on next pages
   * @npage_lpa: Modes advertised by link partner on next pages
   *

   * The @ecmd parameter is expected to have been cleared before calling
   * mdio45_ethtool_gset_npage().
   *

   * Since the CSRs for auto-negotiation using next pages are not fully
   * standardised, this function does not attempt to decode them.  The
   * caller must pass them in.
   */
  void mdio45_ethtool_gset_npage(const struct mdio_if_info *mdio,
  			       struct ethtool_cmd *ecmd,
  			       u32 npage_adv, u32 npage_lpa)
  {
  	int reg;

  	u32 speed;

  	BUILD_BUG_ON(MDIO_SUPPORTS_C22 != ETH_MDIO_SUPPORTS_C22);
  	BUILD_BUG_ON(MDIO_SUPPORTS_C45 != ETH_MDIO_SUPPORTS_C45);

  	ecmd->transceiver = XCVR_INTERNAL;
  	ecmd->phy_address = mdio->prtad;

  	ecmd->mdio_support =
  		mdio->mode_support & (MDIO_SUPPORTS_C45 | MDIO_SUPPORTS_C22);

  
  	reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
  			      MDIO_CTRL2);
  	switch (reg & MDIO_PMA_CTRL2_TYPE) {
  	case MDIO_PMA_CTRL2_10GBT:
  	case MDIO_PMA_CTRL2_1000BT:
  	case MDIO_PMA_CTRL2_100BTX:
  	case MDIO_PMA_CTRL2_10BT:
  		ecmd->port = PORT_TP;
  		ecmd->supported = SUPPORTED_TP;
  		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
  				      MDIO_SPEED);
  		if (reg & MDIO_SPEED_10G)
  			ecmd->supported |= SUPPORTED_10000baseT_Full;
  		if (reg & MDIO_PMA_SPEED_1000)
  			ecmd->supported |= (SUPPORTED_1000baseT_Full |
  					    SUPPORTED_1000baseT_Half);
  		if (reg & MDIO_PMA_SPEED_100)
  			ecmd->supported |= (SUPPORTED_100baseT_Full |
  					    SUPPORTED_100baseT_Half);
  		if (reg & MDIO_PMA_SPEED_10)
  			ecmd->supported |= (SUPPORTED_10baseT_Full |
  					    SUPPORTED_10baseT_Half);
  		ecmd->advertising = ADVERTISED_TP;
  		break;
  
  	case MDIO_PMA_CTRL2_10GBCX4:

  		ecmd->port = PORT_OTHER;
  		ecmd->supported = 0;
  		ecmd->advertising = 0;
  		break;

  	case MDIO_PMA_CTRL2_10GBKX4:
  	case MDIO_PMA_CTRL2_10GBKR:
  	case MDIO_PMA_CTRL2_1000BKX:
  		ecmd->port = PORT_OTHER;

  		ecmd->supported = SUPPORTED_Backplane;
  		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
  				      MDIO_PMA_EXTABLE);
  		if (reg & MDIO_PMA_EXTABLE_10GBKX4)
  			ecmd->supported |= SUPPORTED_10000baseKX4_Full;
  		if (reg & MDIO_PMA_EXTABLE_10GBKR)
  			ecmd->supported |= SUPPORTED_10000baseKR_Full;
  		if (reg & MDIO_PMA_EXTABLE_1000BKX)
  			ecmd->supported |= SUPPORTED_1000baseKX_Full;
  		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
  				      MDIO_PMA_10GBR_FECABLE);
  		if (reg & MDIO_PMA_10GBR_FECABLE_ABLE)
  			ecmd->supported |= SUPPORTED_10000baseR_FEC;
  		ecmd->advertising = ADVERTISED_Backplane;

  		break;
  
  	/* All the other defined modes are flavours of optical */
  	default:
  		ecmd->port = PORT_FIBRE;
  		ecmd->supported = SUPPORTED_FIBRE;
  		ecmd->advertising = ADVERTISED_FIBRE;
  		break;
  	}
  
  	if (mdio->mmds & MDIO_DEVS_AN) {
  		ecmd->supported |= SUPPORTED_Autoneg;
  		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_AN,
  				      MDIO_CTRL1);
  		if (reg & MDIO_AN_CTRL1_ENABLE) {
  			ecmd->autoneg = AUTONEG_ENABLE;
  			ecmd->advertising |=
  				ADVERTISED_Autoneg |
  				mdio45_get_an(mdio, MDIO_AN_ADVERTISE) |
  				npage_adv;
  		} else {
  			ecmd->autoneg = AUTONEG_DISABLE;
  		}
  	} else {
  		ecmd->autoneg = AUTONEG_DISABLE;
  	}
  
  	if (ecmd->autoneg) {
  		u32 modes = 0;

  		int an_stat = mdio->mdio_read(mdio->dev, mdio->prtad,
  					      MDIO_MMD_AN, MDIO_STAT1);

  
  		/* If AN is complete and successful, report best common
  		 * mode, otherwise report best advertised mode. */

  		if (an_stat & MDIO_AN_STAT1_COMPLETE) {
  			ecmd->lp_advertising =
  				mdio45_get_an(mdio, MDIO_AN_LPA) | npage_lpa;
  			if (an_stat & MDIO_AN_STAT1_LPABLE)
  				ecmd->lp_advertising |= ADVERTISED_Autoneg;
  			modes = ecmd->advertising & ecmd->lp_advertising;
  		}
  		if ((modes & ~ADVERTISED_Autoneg) == 0)

  			modes = ecmd->advertising;

  		if (modes & (ADVERTISED_10000baseT_Full |
  			     ADVERTISED_10000baseKX4_Full |
  			     ADVERTISED_10000baseKR_Full)) {

  			speed = SPEED_10000;

  			ecmd->duplex = DUPLEX_FULL;
  		} else if (modes & (ADVERTISED_1000baseT_Full |

  				    ADVERTISED_1000baseT_Half |
  				    ADVERTISED_1000baseKX_Full)) {

  			speed = SPEED_1000;

  			ecmd->duplex = !(modes & ADVERTISED_1000baseT_Half);

  		} else if (modes & (ADVERTISED_100baseT_Full |
  				    ADVERTISED_100baseT_Half)) {

  			speed = SPEED_100;

  			ecmd->duplex = !!(modes & ADVERTISED_100baseT_Full);
  		} else {

  			speed = SPEED_10;

  			ecmd->duplex = !!(modes & ADVERTISED_10baseT_Full);
  		}
  	} else {
  		/* Report forced settings */
  		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
  				      MDIO_CTRL1);

  		speed = (((reg & MDIO_PMA_CTRL1_SPEED1000) ? 100 : 1)
  			 * ((reg & MDIO_PMA_CTRL1_SPEED100) ? 100 : 10));

  		ecmd->duplex = (reg & MDIO_CTRL1_FULLDPLX ||

  				speed == SPEED_10000);

  	}

  	ethtool_cmd_speed_set(ecmd, speed);

  	/* 10GBASE-T MDI/MDI-X */

  	if (ecmd->port == PORT_TP
  	    && (ethtool_cmd_speed(ecmd) == SPEED_10000)) {

  		switch (mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
  					MDIO_PMA_10GBT_SWAPPOL)) {
  		case MDIO_PMA_10GBT_SWAPPOL_ABNX | MDIO_PMA_10GBT_SWAPPOL_CDNX:
  			ecmd->eth_tp_mdix = ETH_TP_MDI;
  			break;
  		case 0:
  			ecmd->eth_tp_mdix = ETH_TP_MDI_X;
  			break;
  		default:
  			/* It's complicated... */
  			ecmd->eth_tp_mdix = ETH_TP_MDI_INVALID;
  			break;
  		}
  	}

  }
  EXPORT_SYMBOL(mdio45_ethtool_gset_npage);
  
  /**
   * mdio_mii_ioctl - MII ioctl interface for MDIO (clause 22 or 45) PHYs
   * @mdio: MDIO interface
   * @mii_data: MII ioctl data structure
   * @cmd: MII ioctl command
   *
   * Returns 0 on success, negative on error.
   */
  int mdio_mii_ioctl(const struct mdio_if_info *mdio,
  		   struct mii_ioctl_data *mii_data, int cmd)
  {
  	int prtad, devad;
  	u16 addr = mii_data->reg_num;
  
  	/* Validate/convert cmd to one of SIOC{G,S}MIIREG */
  	switch (cmd) {
  	case SIOCGMIIPHY:
  		if (mdio->prtad == MDIO_PRTAD_NONE)
  			return -EOPNOTSUPP;
  		mii_data->phy_id = mdio->prtad;
  		cmd = SIOCGMIIREG;
  		break;
  	case SIOCGMIIREG:

  	case SIOCSMIIREG:

  		break;
  	default:
  		return -EOPNOTSUPP;
  	}
  
  	/* Validate/convert phy_id */
  	if ((mdio->mode_support & MDIO_SUPPORTS_C45) &&
  	    mdio_phy_id_is_c45(mii_data->phy_id)) {
  		prtad = mdio_phy_id_prtad(mii_data->phy_id);
  		devad = mdio_phy_id_devad(mii_data->phy_id);
  	} else if ((mdio->mode_support & MDIO_SUPPORTS_C22) &&
  		   mii_data->phy_id < 0x20) {
  		prtad = mii_data->phy_id;
  		devad = MDIO_DEVAD_NONE;
  		addr &= 0x1f;
  	} else if ((mdio->mode_support & MDIO_EMULATE_C22) &&
  		   mdio->prtad != MDIO_PRTAD_NONE &&
  		   mii_data->phy_id == mdio->prtad) {
  		/* Remap commonly-used MII registers. */
  		prtad = mdio->prtad;
  		switch (addr) {
  		case MII_BMCR:
  		case MII_BMSR:
  		case MII_PHYSID1:
  		case MII_PHYSID2:
  			devad = __ffs(mdio->mmds);
  			break;
  		case MII_ADVERTISE:
  		case MII_LPA:
  			if (!(mdio->mmds & MDIO_DEVS_AN))
  				return -EINVAL;
  			devad = MDIO_MMD_AN;
  			if (addr == MII_ADVERTISE)
  				addr = MDIO_AN_ADVERTISE;
  			else
  				addr = MDIO_AN_LPA;
  			break;
  		default:
  			return -EINVAL;
  		}
  	} else {
  		return -EINVAL;
  	}
  
  	if (cmd == SIOCGMIIREG) {
  		int rc = mdio->mdio_read(mdio->dev, prtad, devad, addr);
  		if (rc < 0)
  			return rc;
  		mii_data->val_out = rc;
  		return 0;
  	} else {
  		return mdio->mdio_write(mdio->dev, prtad, devad, addr,
  					mii_data->val_in);
  	}
  }
  EXPORT_SYMBOL(mdio_mii_ioctl);