drivers/net/mdio.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * mdio.c: Generic support for MDIO-compatible transceivers
  * Copyright 2006-2009 Solarflare Communications Inc.
  */

 #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);

 /**
  * mdio45_links_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);

 /**
  * mdio45_ethtool_ksettings_get_npage - get settings for ETHTOOL_GLINKSETTINGS
  * @mdio: MDIO interface
  * @cmd: Ethtool request structure
  * @npage_adv: Modes currently advertised on next pages
  * @npage_lpa: Modes advertised by link partner on next pages
  *
  * The @cmd parameter is expected to have been cleared before calling
  * mdio45_ethtool_ksettings_get_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_ksettings_get_npage(const struct mdio_if_info *mdio,
 					struct ethtool_link_ksettings *cmd,
 					u32 npage_adv, u32 npage_lpa)
 {
 	int reg;
 	u32 speed, supported = 0, advertising = 0, lp_advertising = 0;

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

 	cmd->base.phy_address = mdio->prtad;
 	cmd->base.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:
 		cmd->base.port = PORT_TP;
 		supported = SUPPORTED_TP;
 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
 				      MDIO_SPEED);
 		if (reg & MDIO_SPEED_10G)
 			supported |= SUPPORTED_10000baseT_Full;
 		if (reg & MDIO_PMA_SPEED_1000)
 			supported |= (SUPPORTED_1000baseT_Full |
 					    SUPPORTED_1000baseT_Half);
 		if (reg & MDIO_PMA_SPEED_100)
 			supported |= (SUPPORTED_100baseT_Full |
 					    SUPPORTED_100baseT_Half);
 		if (reg & MDIO_PMA_SPEED_10)
 			supported |= (SUPPORTED_10baseT_Full |
 					    SUPPORTED_10baseT_Half);
 		advertising = ADVERTISED_TP;
 		break;

 	case MDIO_PMA_CTRL2_10GBCX4:
 		cmd->base.port = PORT_OTHER;
 		supported = 0;
 		advertising = 0;
 		break;

 	case MDIO_PMA_CTRL2_10GBKX4:
 	case MDIO_PMA_CTRL2_10GBKR:
 	case MDIO_PMA_CTRL2_1000BKX:
 		cmd->base.port = PORT_OTHER;
 		supported = SUPPORTED_Backplane;
 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
 				      MDIO_PMA_EXTABLE);
 		if (reg & MDIO_PMA_EXTABLE_10GBKX4)
 			supported |= SUPPORTED_10000baseKX4_Full;
 		if (reg & MDIO_PMA_EXTABLE_10GBKR)
 			supported |= SUPPORTED_10000baseKR_Full;
 		if (reg & MDIO_PMA_EXTABLE_1000BKX)
 			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)
 			supported |= SUPPORTED_10000baseR_FEC;
 		advertising = ADVERTISED_Backplane;
 		break;

 	/* All the other defined modes are flavours of optical */
 	default:
 		cmd->base.port = PORT_FIBRE;
 		supported = SUPPORTED_FIBRE;
 		advertising = ADVERTISED_FIBRE;
 		break;
 	}

 	if (mdio->mmds & MDIO_DEVS_AN) {
 		supported |= SUPPORTED_Autoneg;
 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_AN,
 				      MDIO_CTRL1);
 		if (reg & MDIO_AN_CTRL1_ENABLE) {
 			cmd->base.autoneg = AUTONEG_ENABLE;
 			advertising |=
 				ADVERTISED_Autoneg |
 				mdio45_get_an(mdio, MDIO_AN_ADVERTISE) |
 				npage_adv;
 		} else {
 			cmd->base.autoneg = AUTONEG_DISABLE;
 		}
 	} else {
 		cmd->base.autoneg = AUTONEG_DISABLE;
 	}

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

 		if (modes & (ADVERTISED_10000baseT_Full |
 			     ADVERTISED_10000baseKX4_Full |
 			     ADVERTISED_10000baseKR_Full)) {
 			speed = SPEED_10000;
 			cmd->base.duplex = DUPLEX_FULL;
 		} else if (modes & (ADVERTISED_1000baseT_Full |
 				    ADVERTISED_1000baseT_Half |
 				    ADVERTISED_1000baseKX_Full)) {
 			speed = SPEED_1000;
 			cmd->base.duplex = !(modes & ADVERTISED_1000baseT_Half);
 		} else if (modes & (ADVERTISED_100baseT_Full |
 				    ADVERTISED_100baseT_Half)) {
 			speed = SPEED_100;
 			cmd->base.duplex = !!(modes & ADVERTISED_100baseT_Full);
 		} else {
 			speed = SPEED_10;
 			cmd->base.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));
 		cmd->base.duplex = (reg & MDIO_CTRL1_FULLDPLX ||
 				    speed == SPEED_10000);
 	}

 	cmd->base.speed = speed;

 	ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.supported,
 						supported);
 	ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.advertising,
 						advertising);
 	ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.lp_advertising,
 						lp_advertising);

 	/* 10GBASE-T MDI/MDI-X */
 	if (cmd->base.port == PORT_TP && (cmd->base.speed == 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:
 			cmd->base.eth_tp_mdix = ETH_TP_MDI;
 			break;
 		case 0:
 			cmd->base.eth_tp_mdix = ETH_TP_MDI_X;
 			break;
 		default:
 			/* It's complicated... */
 			cmd->base.eth_tp_mdix = ETH_TP_MDI_INVALID;
 			break;
 		}
 	}
 }
 EXPORT_SYMBOL(mdio45_ethtool_ksettings_get_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);
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* mdio.c: Generic support for MDIO-compatible transceivers
	* Copyright 2006-2009 Solarflare Communications Inc.
	*/

	#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);

	/**
	* mdio45_links_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);

	/**
	* mdio45_ethtool_ksettings_get_npage - get settings for ETHTOOL_GLINKSETTINGS
	* @mdio: MDIO interface
	* @cmd: Ethtool request structure
	* @npage_adv: Modes currently advertised on next pages
	* @npage_lpa: Modes advertised by link partner on next pages
	*
	* The @cmd parameter is expected to have been cleared before calling
	* mdio45_ethtool_ksettings_get_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_ksettings_get_npage(const struct mdio_if_info *mdio,
	struct ethtool_link_ksettings *cmd,
	u32 npage_adv, u32 npage_lpa)
	{
	int reg;
	u32 speed, supported = 0, advertising = 0, lp_advertising = 0;

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

	cmd->base.phy_address = mdio->prtad;
	cmd->base.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:
	cmd->base.port = PORT_TP;
	supported = SUPPORTED_TP;
	reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
	MDIO_SPEED);
	if (reg & MDIO_SPEED_10G)
	supported \|= SUPPORTED_10000baseT_Full;
	if (reg & MDIO_PMA_SPEED_1000)
	supported \|= (SUPPORTED_1000baseT_Full \|
	SUPPORTED_1000baseT_Half);
	if (reg & MDIO_PMA_SPEED_100)
	supported \|= (SUPPORTED_100baseT_Full \|
	SUPPORTED_100baseT_Half);
	if (reg & MDIO_PMA_SPEED_10)
	supported \|= (SUPPORTED_10baseT_Full \|
	SUPPORTED_10baseT_Half);
	advertising = ADVERTISED_TP;
	break;

	case MDIO_PMA_CTRL2_10GBCX4:
	cmd->base.port = PORT_OTHER;
	supported = 0;
	advertising = 0;
	break;

	case MDIO_PMA_CTRL2_10GBKX4:
	case MDIO_PMA_CTRL2_10GBKR:
	case MDIO_PMA_CTRL2_1000BKX:
	cmd->base.port = PORT_OTHER;
	supported = SUPPORTED_Backplane;
	reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
	MDIO_PMA_EXTABLE);
	if (reg & MDIO_PMA_EXTABLE_10GBKX4)
	supported \|= SUPPORTED_10000baseKX4_Full;
	if (reg & MDIO_PMA_EXTABLE_10GBKR)
	supported \|= SUPPORTED_10000baseKR_Full;
	if (reg & MDIO_PMA_EXTABLE_1000BKX)
	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)
	supported \|= SUPPORTED_10000baseR_FEC;
	advertising = ADVERTISED_Backplane;
	break;

	/* All the other defined modes are flavours of optical */
	default:
	cmd->base.port = PORT_FIBRE;
	supported = SUPPORTED_FIBRE;
	advertising = ADVERTISED_FIBRE;
	break;
	}

	if (mdio->mmds & MDIO_DEVS_AN) {
	supported \|= SUPPORTED_Autoneg;
	reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_AN,
	MDIO_CTRL1);
	if (reg & MDIO_AN_CTRL1_ENABLE) {
	cmd->base.autoneg = AUTONEG_ENABLE;
	advertising \|=
	ADVERTISED_Autoneg \|
	mdio45_get_an(mdio, MDIO_AN_ADVERTISE) \|
	npage_adv;
	} else {
	cmd->base.autoneg = AUTONEG_DISABLE;
	}
	} else {
	cmd->base.autoneg = AUTONEG_DISABLE;
	}

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

	if (modes & (ADVERTISED_10000baseT_Full \|
	ADVERTISED_10000baseKX4_Full \|
	ADVERTISED_10000baseKR_Full)) {
	speed = SPEED_10000;
	cmd->base.duplex = DUPLEX_FULL;
	} else if (modes & (ADVERTISED_1000baseT_Full \|
	ADVERTISED_1000baseT_Half \|
	ADVERTISED_1000baseKX_Full)) {
	speed = SPEED_1000;
	cmd->base.duplex = !(modes & ADVERTISED_1000baseT_Half);
	} else if (modes & (ADVERTISED_100baseT_Full \|
	ADVERTISED_100baseT_Half)) {
	speed = SPEED_100;
	cmd->base.duplex = !!(modes & ADVERTISED_100baseT_Full);
	} else {
	speed = SPEED_10;
	cmd->base.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));
	cmd->base.duplex = (reg & MDIO_CTRL1_FULLDPLX \|\|
	speed == SPEED_10000);
	}

	cmd->base.speed = speed;

	ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.supported,
	supported);
	ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.advertising,
	advertising);
	ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.lp_advertising,
	lp_advertising);

	/* 10GBASE-T MDI/MDI-X */
	if (cmd->base.port == PORT_TP && (cmd->base.speed == 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:
	cmd->base.eth_tp_mdix = ETH_TP_MDI;
	break;
	case 0:
	cmd->base.eth_tp_mdix = ETH_TP_MDI_X;
	break;
	default:
	/* It's complicated... */
	cmd->base.eth_tp_mdix = ETH_TP_MDI_INVALID;
	break;
	}
	}
	}
	EXPORT_SYMBOL(mdio45_ethtool_ksettings_get_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);