/*      $NetBSD: igc_phy.c,v 1.2 2023/10/04 07:35:27 rin Exp $  */
/*      $OpenBSD: igc_phy.c,v 1.3 2023/02/03 11:31:52 mbuhl Exp $       */
/*-
* Copyright 2021 Intel Corp
* Copyright 2021 Rubicon Communications, LLC (Netgate)
* SPDX-License-Identifier: BSD-3-Clause
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: igc_phy.c,v 1.2 2023/10/04 07:35:27 rin Exp $");

#include <dev/pci/igc/igc_api.h>
#include <dev/mii/mii.h>

/**
*  igc_init_phy_ops_generic - Initialize PHY function pointers
*  @hw: pointer to the HW structure
*
*  Setups up the function pointers to no-op functions
**/
void
igc_init_phy_ops_generic(struct igc_hw *hw)
{
       struct igc_phy_info *phy = &hw->phy;
       DEBUGFUNC("igc_init_phy_ops_generic");

       /* Initialize function pointers */
       phy->ops.init_params = igc_null_ops_generic;
       phy->ops.acquire = igc_null_ops_generic;
       phy->ops.check_reset_block = igc_null_ops_generic;
       phy->ops.force_speed_duplex = igc_null_ops_generic;
       phy->ops.get_info = igc_null_ops_generic;
       phy->ops.set_page = igc_null_set_page;
       phy->ops.read_reg = igc_null_read_reg;
       phy->ops.read_reg_locked = igc_null_read_reg;
       phy->ops.read_reg_page = igc_null_read_reg;
       phy->ops.release = igc_null_phy_generic;
       phy->ops.reset = igc_null_ops_generic;
       phy->ops.set_d0_lplu_state = igc_null_lplu_state;
       phy->ops.set_d3_lplu_state = igc_null_lplu_state;
       phy->ops.write_reg = igc_null_write_reg;
       phy->ops.write_reg_locked = igc_null_write_reg;
       phy->ops.write_reg_page = igc_null_write_reg;
       phy->ops.power_up = igc_null_phy_generic;
       phy->ops.power_down = igc_null_phy_generic;
}

/**
*  igc_null_set_page - No-op function, return 0
*  @hw: pointer to the HW structure
*  @data: dummy variable
**/
int
igc_null_set_page(struct igc_hw IGC_UNUSEDARG *hw, uint16_t IGC_UNUSEDARG data)
{
       DEBUGFUNC("igc_null_set_page");
       return IGC_SUCCESS;
}

/**
*  igc_null_read_reg - No-op function, return 0
*  @hw: pointer to the HW structure
*  @offset: dummy variable
*  @data: dummy variable
**/
int
igc_null_read_reg(struct igc_hw IGC_UNUSEDARG *hw,
   uint32_t IGC_UNUSEDARG offset, uint16_t IGC_UNUSEDARG *data)
{
       DEBUGFUNC("igc_null_read_reg");
       return IGC_SUCCESS;
}

/**
*  igc_null_phy_generic - No-op function, return void
*  @hw: pointer to the HW structure
**/
void
igc_null_phy_generic(struct igc_hw IGC_UNUSEDARG *hw)
{
       DEBUGFUNC("igc_null_phy_generic");
       return;
}

/**
*  igc_null_lplu_state - No-op function, return 0
*  @hw: pointer to the HW structure
*  @active: dummy variable
**/
int
igc_null_lplu_state(struct igc_hw IGC_UNUSEDARG *hw, bool IGC_UNUSEDARG active)
{
       DEBUGFUNC("igc_null_lplu_state");
       return IGC_SUCCESS;
}

/**
*  igc_null_write_reg - No-op function, return 0
*  @hw: pointer to the HW structure
*  @offset: dummy variable
*  @data: dummy variable
**/
int
igc_null_write_reg(struct igc_hw IGC_UNUSEDARG *hw,
   uint32_t IGC_UNUSEDARG offset, uint16_t IGC_UNUSEDARG data)
{
       DEBUGFUNC("igc_null_write_reg");
       return IGC_SUCCESS;
}

/**
*  igc_check_reset_block_generic - Check if PHY reset is blocked
*  @hw: pointer to the HW structure
*
*  Read the PHY management control register and check whether a PHY reset
*  is blocked.  If a reset is not blocked return IGC_SUCCESS, otherwise
*  return IGC_BLK_PHY_RESET (12).
**/
int
igc_check_reset_block_generic(struct igc_hw *hw)
{
       uint32_t manc;

       DEBUGFUNC("igc_check_reset_block");

       manc = IGC_READ_REG(hw, IGC_MANC);

       return (manc & IGC_MANC_BLK_PHY_RST_ON_IDE) ?
           IGC_BLK_PHY_RESET : IGC_SUCCESS;
}

/**
*  igc_get_phy_id - Retrieve the PHY ID and revision
*  @hw: pointer to the HW structure
*
*  Reads the PHY registers and stores the PHY ID and possibly the PHY
*  revision in the hardware structure.
**/
int
igc_get_phy_id(struct igc_hw *hw)
{
       struct igc_phy_info *phy = &hw->phy;
       uint16_t phy_id;
       int ret_val = IGC_SUCCESS;

       DEBUGFUNC("igc_get_phy_id");

       if (!phy->ops.read_reg)
               return IGC_SUCCESS;

       ret_val = phy->ops.read_reg(hw, PHY_ID1, &phy_id);
       if (ret_val)
               return ret_val;

       phy->id = (uint32_t)(phy_id << 16);
       DELAY(200);
       ret_val = phy->ops.read_reg(hw, PHY_ID2, &phy_id);
       if (ret_val)
               return ret_val;

       phy->id |= (uint32_t)(phy_id & PHY_REVISION_MASK);
       phy->revision = (uint32_t)(phy_id & ~PHY_REVISION_MASK);

       return IGC_SUCCESS;
}

/**
*  igc_read_phy_reg_mdic - Read MDI control register
*  @hw: pointer to the HW structure
*  @offset: register offset to be read
*  @data: pointer to the read data
*
*  Reads the MDI control register in the PHY at offset and stores the
*  information read to data.
**/
int
igc_read_phy_reg_mdic(struct igc_hw *hw, uint32_t offset, uint16_t *data)
{
       struct igc_phy_info *phy = &hw->phy;
       uint32_t i, mdic = 0;

       DEBUGFUNC("igc_read_phy_reg_mdic");

       if (offset > MAX_PHY_REG_ADDRESS) {
               DEBUGOUT1("PHY Address %d is out of range\n", offset);
               return -IGC_ERR_PARAM;
       }

       /* Set up Op-code, Phy Address, and register offset in the MDI
        * Control register.  The MAC will take care of interfacing with the
        * PHY to retrieve the desired data.
        */
       mdic = ((offset << IGC_MDIC_REG_SHIFT) |
           (phy->addr << IGC_MDIC_PHY_SHIFT) | (IGC_MDIC_OP_READ));

       IGC_WRITE_REG(hw, IGC_MDIC, mdic);

       /* Poll the ready bit to see if the MDI read completed
        * Increasing the time out as testing showed failures with
        * the lower time out
        */
       for (i = 0; i < (IGC_GEN_POLL_TIMEOUT * 3); i++) {
               DELAY(50);
               mdic = IGC_READ_REG(hw, IGC_MDIC);
               if (mdic & IGC_MDIC_READY)
                       break;
       }
       if (!(mdic & IGC_MDIC_READY)) {
               DEBUGOUT("MDI Read did not complete\n");
               return -IGC_ERR_PHY;
       }
       if (mdic & IGC_MDIC_ERROR) {
               DEBUGOUT("MDI Error\n");
               return -IGC_ERR_PHY;
       }
       if (((mdic & IGC_MDIC_REG_MASK) >> IGC_MDIC_REG_SHIFT) != offset) {
               DEBUGOUT2("MDI Read offset error - requested %d, returned %d\n",
                   offset, (mdic & IGC_MDIC_REG_MASK) >> IGC_MDIC_REG_SHIFT);
               return -IGC_ERR_PHY;
       }
       *data = (uint16_t)mdic;

       return IGC_SUCCESS;
}

/**
*  igc_write_phy_reg_mdic - Write MDI control register
*  @hw: pointer to the HW structure
*  @offset: register offset to write to
*  @data: data to write to register at offset
*
*  Writes data to MDI control register in the PHY at offset.
**/
int
igc_write_phy_reg_mdic(struct igc_hw *hw, uint32_t offset, uint16_t data)
{
       struct igc_phy_info *phy = &hw->phy;
       uint32_t i, mdic = 0;

       DEBUGFUNC("igc_write_phy_reg_mdic");

       if (offset > MAX_PHY_REG_ADDRESS) {
               DEBUGOUT1("PHY Address %d is out of range\n", offset);
               return -IGC_ERR_PARAM;
       }

       /* Set up Op-code, Phy Address, and register offset in the MDI
        * Control register.  The MAC will take care of interfacing with the
        * PHY to retrieve the desired data.
        */
       mdic = (((uint32_t)data) | (offset << IGC_MDIC_REG_SHIFT) |
           (phy->addr << IGC_MDIC_PHY_SHIFT) | (IGC_MDIC_OP_WRITE));

       IGC_WRITE_REG(hw, IGC_MDIC, mdic);

       /* Poll the ready bit to see if the MDI read completed
        * Increasing the time out as testing showed failures with
        * the lower time out
        */
       for (i = 0; i < (IGC_GEN_POLL_TIMEOUT * 3); i++) {
               DELAY(50);
               mdic = IGC_READ_REG(hw, IGC_MDIC);
               if (mdic & IGC_MDIC_READY)
                       break;
       }
       if (!(mdic & IGC_MDIC_READY)) {
               DEBUGOUT("MDI Write did not complete\n");
               return -IGC_ERR_PHY;
       }
       if (mdic & IGC_MDIC_ERROR) {
               DEBUGOUT("MDI Error\n");
               return -IGC_ERR_PHY;
       }
       if (((mdic & IGC_MDIC_REG_MASK) >> IGC_MDIC_REG_SHIFT) != offset)
               return -IGC_ERR_PHY;

       return IGC_SUCCESS;
}

/**
*  igc_phy_setup_autoneg - Configure PHY for auto-negotiation
*  @hw: pointer to the HW structure
*
*  Reads the MII auto-neg advertisement register and/or the 1000T control
*  register and if the PHY is already setup for auto-negotiation, then
*  return successful.  Otherwise, setup advertisement and flow control to
*  the appropriate values for the wanted auto-negotiation.
**/
static int
igc_phy_setup_autoneg(struct igc_hw *hw)
{
       struct igc_phy_info *phy = &hw->phy;
       uint16_t mii_autoneg_adv_reg;
       uint16_t mii_1000t_ctrl_reg = 0;
       uint16_t aneg_multigbt_an_ctrl = 0;
       int ret_val;

       DEBUGFUNC("igc_phy_setup_autoneg");

       phy->autoneg_advertised &= phy->autoneg_mask;

       /* Read the MII Auto-Neg Advertisement Register (Address 4). */
       ret_val = phy->ops.read_reg(hw, PHY_AUTONEG_ADV, &mii_autoneg_adv_reg);
       if (ret_val)
               return ret_val;

       if (phy->autoneg_mask & ADVERTISE_1000_FULL) {
               /* Read the MII 1000Base-T Control Register (Address 9). */
               ret_val = phy->ops.read_reg(hw, PHY_1000T_CTRL,
                   &mii_1000t_ctrl_reg);
               if (ret_val)
                       return ret_val;
       }

       if (phy->autoneg_mask & ADVERTISE_2500_FULL) {
               /* Read the MULTI GBT AN Control Register - reg 7.32 */
               ret_val = phy->ops.read_reg(hw, (STANDARD_AN_REG_MASK <<
                   MMD_DEVADDR_SHIFT) | ANEG_MULTIGBT_AN_CTRL,
                   &aneg_multigbt_an_ctrl);
               if (ret_val)
                       return ret_val;
       }

       /* Need to parse both autoneg_advertised and fc and set up
        * the appropriate PHY registers.  First we will parse for
        * autoneg_advertised software override.  Since we can advertise
        * a plethora of combinations, we need to check each bit
        * individually.
        */

       /* First we clear all the 10/100 mb speed bits in the Auto-Neg
        * Advertisement Register (Address 4) and the 1000 mb speed bits in
        * the  1000Base-T Control Register (Address 9).
        */
       mii_autoneg_adv_reg &= ~(NWAY_AR_100TX_FD_CAPS | NWAY_AR_100TX_HD_CAPS |
           NWAY_AR_10T_FD_CAPS | NWAY_AR_10T_HD_CAPS);
       mii_1000t_ctrl_reg &= ~(CR_1000T_HD_CAPS | CR_1000T_FD_CAPS);

       DEBUGOUT1("autoneg_advertised %x\n", phy->autoneg_advertised);

       /* Do we want to advertise 10 Mb Half Duplex? */
       if (phy->autoneg_advertised & ADVERTISE_10_HALF) {
               DEBUGOUT("Advertise 10mb Half duplex\n");
               mii_autoneg_adv_reg |= NWAY_AR_10T_HD_CAPS;
       }

       /* Do we want to advertise 10 Mb Full Duplex? */
       if (phy->autoneg_advertised & ADVERTISE_10_FULL) {
               DEBUGOUT("Advertise 10mb Full duplex\n");
               mii_autoneg_adv_reg |= NWAY_AR_10T_FD_CAPS;
       }

       /* Do we want to advertise 100 Mb Half Duplex? */
       if (phy->autoneg_advertised & ADVERTISE_100_HALF) {
               DEBUGOUT("Advertise 100mb Half duplex\n");
               mii_autoneg_adv_reg |= NWAY_AR_100TX_HD_CAPS;
       }

       /* Do we want to advertise 100 Mb Full Duplex? */
       if (phy->autoneg_advertised & ADVERTISE_100_FULL) {
               DEBUGOUT("Advertise 100mb Full duplex\n");
               mii_autoneg_adv_reg |= NWAY_AR_100TX_FD_CAPS;
       }

       /* We do not allow the Phy to advertise 1000 Mb Half Duplex */
       if (phy->autoneg_advertised & ADVERTISE_1000_HALF)
               DEBUGOUT("Advertise 1000mb Half duplex request denied!\n");

       /* Do we want to advertise 1000 Mb Full Duplex? */
       if (phy->autoneg_advertised & ADVERTISE_1000_FULL) {
               DEBUGOUT("Advertise 1000mb Full duplex\n");
               mii_1000t_ctrl_reg |= CR_1000T_FD_CAPS;
       }

       /* We do not allow the Phy to advertise 2500 Mb Half Duplex */
       if (phy->autoneg_advertised & ADVERTISE_2500_HALF)
               DEBUGOUT("Advertise 2500mb Half duplex request denied!\n");

       /* Do we want to advertise 2500 Mb Full Duplex? */
       if (phy->autoneg_advertised & ADVERTISE_2500_FULL) {
               DEBUGOUT("Advertise 2500mb Full duplex\n");
               aneg_multigbt_an_ctrl |= CR_2500T_FD_CAPS;
       } else
               aneg_multigbt_an_ctrl &= ~CR_2500T_FD_CAPS;

       /* Check for a software override of the flow control settings, and
        * setup the PHY advertisement registers accordingly.  If
        * auto-negotiation is enabled, then software will have to set the
        * "PAUSE" bits to the correct value in the Auto-Negotiation
        * Advertisement Register (PHY_AUTONEG_ADV) and re-start auto-
        * negotiation.
        *
        * The possible values of the "fc" parameter are:
        *      0:  Flow control is completely disabled
        *      1:  Rx flow control is enabled (we can receive pause frames
        *          but not send pause frames).
        *      2:  Tx flow control is enabled (we can send pause frames
        *          but we do not support receiving pause frames).
        *      3:  Both Rx and Tx flow control (symmetric) are enabled.
        *  other:  No software override.  The flow control configuration
        *          in the EEPROM is used.
        */
       switch (hw->fc.current_mode) {
       case igc_fc_none:
               /* Flow control (Rx & Tx) is completely disabled by a
                * software over-ride.
                */
               mii_autoneg_adv_reg &= ~(NWAY_AR_ASM_DIR | NWAY_AR_PAUSE);
               break;
       case igc_fc_rx_pause:
               /* Rx Flow control is enabled, and Tx Flow control is
                * disabled, by a software over-ride.
                *
                * Since there really isn't a way to advertise that we are
                * capable of Rx Pause ONLY, we will advertise that we
                * support both symmetric and asymmetric Rx PAUSE.  Later
                * (in igc_config_fc_after_link_up) we will disable the
                * hw's ability to send PAUSE frames.
                */
               mii_autoneg_adv_reg |= (NWAY_AR_ASM_DIR | NWAY_AR_PAUSE);
               break;
       case igc_fc_tx_pause:
               /* Tx Flow control is enabled, and Rx Flow control is
                * disabled, by a software over-ride.
                */
               mii_autoneg_adv_reg |= NWAY_AR_ASM_DIR;
               mii_autoneg_adv_reg &= ~NWAY_AR_PAUSE;
               break;
       case igc_fc_full:
               /* Flow control (both Rx and Tx) is enabled by a software
                * over-ride.
                */
               mii_autoneg_adv_reg |= (NWAY_AR_ASM_DIR | NWAY_AR_PAUSE);
               break;
       default:
               DEBUGOUT("Flow control param set incorrectly\n");
               return -IGC_ERR_CONFIG;
       }

       ret_val = phy->ops.write_reg(hw, PHY_AUTONEG_ADV, mii_autoneg_adv_reg);
       if (ret_val)
               return ret_val;

       DEBUGOUT1("Auto-Neg Advertising %x\n", mii_autoneg_adv_reg);

       if (phy->autoneg_mask & ADVERTISE_1000_FULL)
               ret_val = phy->ops.write_reg(hw, PHY_1000T_CTRL,
                   mii_1000t_ctrl_reg);

       if (phy->autoneg_mask & ADVERTISE_2500_FULL)
               ret_val = phy->ops.write_reg(hw,
                   (STANDARD_AN_REG_MASK << MMD_DEVADDR_SHIFT) |
                   ANEG_MULTIGBT_AN_CTRL, aneg_multigbt_an_ctrl);

       return ret_val;
}

/**
*  igc_copper_link_autoneg - Setup/Enable autoneg for copper link
*  @hw: pointer to the HW structure
*
*  Performs initial bounds checking on autoneg advertisement parameter, then
*  configure to advertise the full capability.  Setup the PHY to autoneg
*  and restart the negotiation process between the link partner.  If
*  autoneg_wait_to_complete, then wait for autoneg to complete before exiting.
**/
static int
igc_copper_link_autoneg(struct igc_hw *hw)
{
       struct igc_phy_info *phy = &hw->phy;
       uint16_t phy_ctrl;
       int ret_val;

       DEBUGFUNC("igc_copper_link_autoneg");

       /* Perform some bounds checking on the autoneg advertisement
        * parameter.
        */
       phy->autoneg_advertised &= phy->autoneg_mask;

       /* If autoneg_advertised is zero, we assume it was not defaulted
        * by the calling code so we set to advertise full capability.
        */
       if (!phy->autoneg_advertised)
               phy->autoneg_advertised = phy->autoneg_mask;

       DEBUGOUT("Reconfiguring auto-neg advertisement params\n");
       ret_val = igc_phy_setup_autoneg(hw);
       if (ret_val) {
               DEBUGOUT("Error Setting up Auto-Negotiation\n");
               return ret_val;
       }
       DEBUGOUT("Restarting Auto-Neg\n");

       /* Restart auto-negotiation by setting the Auto Neg Enable bit and
        * the Auto Neg Restart bit in the PHY control register.
        */
       ret_val = phy->ops.read_reg(hw, PHY_CONTROL, &phy_ctrl);
       if (ret_val)
               return ret_val;

       phy_ctrl |= (MII_CR_AUTO_NEG_EN | MII_CR_RESTART_AUTO_NEG);
       ret_val = phy->ops.write_reg(hw, PHY_CONTROL, phy_ctrl);
       if (ret_val)
               return ret_val;

       /* Does the user want to wait for Auto-Neg to complete here, or
        * check at a later time (for example, callback routine).
        */
       if (phy->autoneg_wait_to_complete) {
               ret_val = igc_wait_autoneg(hw);
               if (ret_val)
                       return ret_val;
       }

       hw->mac.get_link_status = true;

       return ret_val;
}

/**
*  igc_setup_copper_link_generic - Configure copper link settings
*  @hw: pointer to the HW structure
*
*  Calls the appropriate function to configure the link for auto-neg or forced
*  speed and duplex.  Then we check for link, once link is established calls
*  to configure collision distance and flow control are called.  If link is
*  not established, we return -IGC_ERR_PHY (-2).
**/
int
igc_setup_copper_link_generic(struct igc_hw *hw)
{
       int ret_val;
       bool link;

       DEBUGFUNC("igc_setup_copper_link_generic");

       if (hw->mac.autoneg) {
               /* Setup autoneg and flow control advertisement and perform
                * autonegotiation.
                */
               ret_val = igc_copper_link_autoneg(hw);
               if (ret_val)
                       return ret_val;
       } else {
               /* PHY will be set to 10H, 10F, 100H or 100F
                * depending on user settings.
                */
               DEBUGOUT("Forcing Speed and Duplex\n");
               ret_val = hw->phy.ops.force_speed_duplex(hw);
               if (ret_val) {
                       DEBUGOUT("Error Forcing Speed and Duplex\n");
                       return ret_val;
               }
       }

       /* Check link status. Wait up to 100 microseconds for link to become
        * valid.
        */
       ret_val = igc_phy_has_link_generic(hw, COPPER_LINK_UP_LIMIT, 10,
           &link);
       if (ret_val)
               return ret_val;

       if (link) {
               DEBUGOUT("Valid link established!!!\n");
               hw->mac.ops.config_collision_dist(hw);
               ret_val = igc_config_fc_after_link_up_generic(hw);
       } else
               DEBUGOUT("Unable to establish link!!!\n");

       return ret_val;
}

/**
*  igc_check_downshift_generic - Checks whether a downshift in speed occurred
*  @hw: pointer to the HW structure
*
*  Success returns 0, Failure returns 1
*
*  A downshift is detected by querying the PHY link health.
**/
int
igc_check_downshift_generic(struct igc_hw *hw)
{
       struct igc_phy_info *phy = &hw->phy;
       int ret_val;

       DEBUGFUNC("igc_check_downshift_generic");

       switch (phy->type) {
       case igc_phy_i225:
       default:
               /* speed downshift not supported */
               phy->speed_downgraded = false;
               return IGC_SUCCESS;
       }

       return ret_val;
}

/**
*  igc_wait_autoneg - Wait for auto-neg completion
*  @hw: pointer to the HW structure
*
*  Waits for auto-negotiation to complete or for the auto-negotiation time
*  limit to expire, which ever happens first.
**/
int
igc_wait_autoneg(struct igc_hw *hw)
{
       uint16_t i, phy_status;
       int ret_val = IGC_SUCCESS;

       DEBUGFUNC("igc_wait_autoneg");

       if (!hw->phy.ops.read_reg)
               return IGC_SUCCESS;

       /* Break after autoneg completes or PHY_AUTO_NEG_LIMIT expires. */
       for (i = PHY_AUTO_NEG_LIMIT; i > 0; i--) {
               ret_val = hw->phy.ops.read_reg(hw, MII_BMSR, &phy_status);
               if (ret_val)
                       break;
               ret_val = hw->phy.ops.read_reg(hw, MII_BMSR, &phy_status);
               if (ret_val)
                       break;
               if (phy_status & MII_SR_AUTONEG_COMPLETE)
                       break;
               msec_delay(100);
       }

       /* PHY_AUTO_NEG_TIME expiration doesn't guarantee auto-negotiation
        * has completed.
        */
       return ret_val;
}

/**
*  igc_phy_has_link_generic - Polls PHY for link
*  @hw: pointer to the HW structure
*  @iterations: number of times to poll for link
*  @usec_interval: delay between polling attempts
*  @success: pointer to whether polling was successful or not
*
*  Polls the PHY status register for link, 'iterations' number of times.
**/
int
igc_phy_has_link_generic(struct igc_hw *hw, uint32_t iterations,
   uint32_t usec_interval, bool *success)
{
       uint16_t i, phy_status;
       int ret_val = IGC_SUCCESS;

       DEBUGFUNC("igc_phy_has_link_generic");

       if (!hw->phy.ops.read_reg)
               return IGC_SUCCESS;

       for (i = 0; i < iterations; i++) {
               /* Some PHYs require the MII_BMSR register to be read
                * twice due to the link bit being sticky.  No harm doing
                * it across the board.
                */
               ret_val = hw->phy.ops.read_reg(hw, MII_BMSR, &phy_status);
               if (ret_val) {
                       /* If the first read fails, another entity may have
                        * ownership of the resources, wait and try again to
                        * see if they have relinquished the resources yet.
                        */
                       if (usec_interval >= 1000)
                               msec_delay(usec_interval/1000);
                       else
                               DELAY(usec_interval);
               }
               ret_val = hw->phy.ops.read_reg(hw, MII_BMSR, &phy_status);
               if (ret_val)
                       break;
               if (phy_status & MII_SR_LINK_STATUS)
                       break;
               if (usec_interval >= 1000)
                       msec_delay(usec_interval/1000);
               else
                       DELAY(usec_interval);
       }

       *success = (i < iterations);

       return ret_val;
}

/**
*  igc_phy_hw_reset_generic - PHY hardware reset
*  @hw: pointer to the HW structure
*
*  Verify the reset block is not blocking us from resetting.  Acquire
*  semaphore (if necessary) and read/set/write the device control reset
*  bit in the PHY.  Wait the appropriate delay time for the device to
*  reset and release the semaphore (if necessary).
**/
int
igc_phy_hw_reset_generic(struct igc_hw *hw)
{
       struct igc_phy_info *phy = &hw->phy;
       uint32_t ctrl, timeout = 10000, phpm = 0;
       int ret_val;

       DEBUGFUNC("igc_phy_hw_reset_generic");

       if (phy->ops.check_reset_block) {
               ret_val = phy->ops.check_reset_block(hw);
               if (ret_val)
                       return IGC_SUCCESS;
       }

       ret_val = phy->ops.acquire(hw);
       if (ret_val)
               return ret_val;

       phpm = IGC_READ_REG(hw, IGC_I225_PHPM);

       ctrl = IGC_READ_REG(hw, IGC_CTRL);
       IGC_WRITE_REG(hw, IGC_CTRL, ctrl | IGC_CTRL_PHY_RST);
       IGC_WRITE_FLUSH(hw);

       DELAY(phy->reset_delay_us);

       IGC_WRITE_REG(hw, IGC_CTRL, ctrl);
       IGC_WRITE_FLUSH(hw);

       DELAY(150);

       do {
               phpm = IGC_READ_REG(hw, IGC_I225_PHPM);
               timeout--;
               DELAY(1);
       } while (!(phpm & IGC_I225_PHPM_RST_COMPL) && timeout);

       if (!timeout)
               DEBUGOUT("Timeout expired after a phy reset\n");

       phy->ops.release(hw);

       return ret_val;
}

/**
* igc_power_up_phy_copper - Restore copper link in case of PHY power down
* @hw: pointer to the HW structure
*
* In the case of a PHY power down to save power, or to turn off link during a
* driver unload, or wake on lan is not enabled, restore the link to previous
* settings.
**/
void
igc_power_up_phy_copper(struct igc_hw *hw)
{
       uint16_t mii_reg = 0;

       /* The PHY will retain its settings across a power down/up cycle */
       hw->phy.ops.read_reg(hw, PHY_CONTROL, &mii_reg);
       mii_reg &= ~MII_CR_POWER_DOWN;
       hw->phy.ops.write_reg(hw, PHY_CONTROL, mii_reg);
       DELAY(300);
}

/**
* igc_power_down_phy_copper - Restore copper link in case of PHY power down
* @hw: pointer to the HW structure
*
* In the case of a PHY power down to save power, or to turn off link during a
* driver unload, or wake on lan is not enabled, restore the link to previous
* settings.
**/
void
igc_power_down_phy_copper(struct igc_hw *hw)
{
       uint16_t mii_reg = 0;

       /* The PHY will retain its settings across a power down/up cycle */
       hw->phy.ops.read_reg(hw, PHY_CONTROL, &mii_reg);
       mii_reg |= MII_CR_POWER_DOWN;
       hw->phy.ops.write_reg(hw, PHY_CONTROL, mii_reg);
       msec_delay(1);
}

/**
*  igc_write_phy_reg_gpy - Write GPY PHY register
*  @hw: pointer to the HW structure
*  @offset: register offset to write to
*  @data: data to write at register offset
*
*  Acquires semaphore, if necessary, then writes the data to PHY register
*  at the offset.  Release any acquired semaphores before exiting.
**/
int
igc_write_phy_reg_gpy(struct igc_hw *hw, uint32_t offset, uint16_t data)
{
       uint8_t dev_addr = (offset & GPY_MMD_MASK) >> GPY_MMD_SHIFT;
       int ret_val;

       DEBUGFUNC("igc_write_phy_reg_gpy");

       offset = offset & GPY_REG_MASK;

       if (!dev_addr) {
               ret_val = hw->phy.ops.acquire(hw);
               if (ret_val)
                       return ret_val;
               ret_val = igc_write_phy_reg_mdic(hw, offset, data);
               if (ret_val)
                       return ret_val;
               hw->phy.ops.release(hw);
       } else {
               ret_val = igc_write_xmdio_reg(hw, (uint16_t)offset, dev_addr,
                   data);
       }

       return ret_val;
}

/**
*  igc_read_phy_reg_gpy - Read GPY PHY register
*  @hw: pointer to the HW structure
*  @offset: lower half is register offset to read to
*     upper half is MMD to use.
*  @data: data to read at register offset
*
*  Acquires semaphore, if necessary, then reads the data in the PHY register
*  at the offset.  Release any acquired semaphores before exiting.
**/
int
igc_read_phy_reg_gpy(struct igc_hw *hw, uint32_t offset, uint16_t *data)
{
       uint8_t dev_addr = (offset & GPY_MMD_MASK) >> GPY_MMD_SHIFT;
       int ret_val;

       DEBUGFUNC("igc_read_phy_reg_gpy");

       offset = offset & GPY_REG_MASK;

       if (!dev_addr) {
               ret_val = hw->phy.ops.acquire(hw);
               if (ret_val)
                       return ret_val;
               ret_val = igc_read_phy_reg_mdic(hw, offset, data);
               if (ret_val)
                       return ret_val;
               hw->phy.ops.release(hw);
       } else {
               ret_val = igc_read_xmdio_reg(hw, (uint16_t)offset, dev_addr,
                   data);
       }

       return ret_val;
}

/**
*  __igc_access_xmdio_reg - Read/write XMDIO register
*  @hw: pointer to the HW structure
*  @address: XMDIO address to program
*  @dev_addr: device address to program
*  @data: pointer to value to read/write from/to the XMDIO address
*  @read: boolean flag to indicate read or write
**/
static int
__igc_access_xmdio_reg(struct igc_hw *hw, uint16_t address, uint8_t dev_addr,
   uint16_t *data, bool read)
{
       int ret_val;

       DEBUGFUNC("__igc_access_xmdio_reg");

       ret_val = hw->phy.ops.write_reg(hw, IGC_MMDAC, dev_addr);
       if (ret_val)
               return ret_val;

       ret_val = hw->phy.ops.write_reg(hw, IGC_MMDAAD, address);
       if (ret_val)
               return ret_val;

       ret_val = hw->phy.ops.write_reg(hw, IGC_MMDAC, IGC_MMDAC_FUNC_DATA |
           dev_addr);
       if (ret_val)
               return ret_val;

       if (read)
               ret_val = hw->phy.ops.read_reg(hw, IGC_MMDAAD, data);
       else
               ret_val = hw->phy.ops.write_reg(hw, IGC_MMDAAD, *data);
       if (ret_val)
               return ret_val;

       /* Recalibrate the device back to 0 */
       ret_val = hw->phy.ops.write_reg(hw, IGC_MMDAC, 0);
       if (ret_val)
               return ret_val;

       return ret_val;
}

/**
*  igc_read_xmdio_reg - Read XMDIO register
*  @hw: pointer to the HW structure
*  @addr: XMDIO address to program
*  @dev_addr: device address to program
*  @data: value to be read from the EMI address
**/
int
igc_read_xmdio_reg(struct igc_hw *hw, uint16_t addr, uint8_t dev_addr,
   uint16_t *data)
{
       DEBUGFUNC("igc_read_xmdio_reg");

       return __igc_access_xmdio_reg(hw, addr, dev_addr, data, true);
}

/**
*  igc_write_xmdio_reg - Write XMDIO register
*  @hw: pointer to the HW structure
*  @addr: XMDIO address to program
*  @dev_addr: device address to program
*  @data: value to be written to the XMDIO address
**/
int
igc_write_xmdio_reg(struct igc_hw *hw, uint16_t addr, uint8_t dev_addr,
   uint16_t data)
{
       DEBUGFUNC("igc_write_xmdio_reg");

       return __igc_access_xmdio_reg(hw, addr, dev_addr, &data, false);
}