lpc17_ethernet.c

 *   Global interrupts are disabled by interrupt handling logic.
 *
 ****************************************************************************/

static void lpc17_txdone(struct lpc17_driver_s *priv)
{
  /* Cancel the pending Tx timeout */

  wd_cancel(priv->lp_txtimeout);

  /* Disable further Tx interrupts.  Tx interrupts may be re-enabled again
   * depending upon the result of the poll.
   */

  priv->lp_inten &= ~ETH_TXINTS;
  lpc17_putreg(priv->lp_inten, LPC17_ETH_INTEN);

  /* Verify that the hardware is ready to send another packet.  Since a Tx
   * just completed, this must be the case.
   */

  DEBUGASSERT(lpc17_txdesc(priv) == OK);

  /* Check if there is a pending Tx transfer that was scheduled by Rx handling
   * while the Tx logic was busy.  If so, processing that pending Tx now.
   */

  if (priv->lp_txpending)
    {
      /* Clear the pending condition, send the packet, and restore Rx interrupts */

      priv->lp_txpending = false;
      EMAC_STAT(priv, tx_unpend);

      lpc17_transmit(priv);

      priv->lp_inten    |= ETH_RXINTS;
      lpc17_putreg(priv->lp_inten, LPC17_ETH_INTEN);
    }

  /* Otherwise poll uIP for new XMIT data */

  else
    {
      (void)uip_poll(&priv->lp_dev, lpc17_uiptxpoll);
    }
}

/****************************************************************************
 * Function: lpc17_interrupt
 *
 * Description:
 *   Hardware interrupt handler
 *
 * Parameters:
 *   irq     - Number of the IRQ that generated the interrupt
 *   context - Interrupt register state save info (architecture-specific)
 *
 * Returned Value:
 *   OK on success
 *
 * Assumptions:
 *
 ****************************************************************************/

static int lpc17_interrupt(int irq, void *context)
{
  register struct lpc17_driver_s *priv = &g_ethdrvr[0];
  uint32_t status;

  /* Get the interrupt status (zero means no interrupts pending). */

  status = lpc17_getreg(LPC17_ETH_INTST);
  if (status != 0)
    {
      /* Handle each pending interrupt */
      /* Check for receive errors */

      if ((status & ETH_INT_RXOVR) != 0)
        {
          lpc17_putreg(ETH_INT_RXOVR, LPC17_ETH_INTCLR);
          EMAC_STAT(priv, rx_ovrerrors);
        }

      if ((status & ETH_INT_RXERR) != 0)
        {
          lpc17_putreg(ETH_INT_RXERR, LPC17_ETH_INTCLR);
          EMAC_STAT(priv, rx_errors);
        }

      /* Check if we received an incoming packet, if so, call lpc17_rxdone() */

      if ((status & ETH_INT_RXFIN) != 0)
        {
          lpc17_putreg(ETH_INT_RXFIN, LPC17_ETH_INTCLR);
          EMAC_STAT(priv, rx_finished);
          DEBUGASSERT(lpc17_getreg(LPC17_ETH_RXPRODIDX) == lpc17_getreg(LPC17_ETH_RXCONSIDX));
        }

      if ((status & ETH_INT_RXDONE) != 0)
        {
          lpc17_putreg(ETH_INT_RXDONE, LPC17_ETH_INTCLR);
          EMAC_STAT(priv, rx_done);
          lpc17_rxdone(priv);
        }

      /* Check for Tx errors */

      if ((status & ETH_INT_TXUNR) != 0)
        {
          lpc17_putreg(ETH_INT_TXUNR, LPC17_ETH_INTCLR);
          EMAC_STAT(priv, tx_underrun);
        }

      if ((status & ETH_INT_TXERR) != 0)
        {
          lpc17_putreg(ETH_INT_TXERR, LPC17_ETH_INTCLR);
          EMAC_STAT(priv, tx_errors);
        }

      /* Check is a packet transmission just completed.  If so, call lpc17_txdone */

      if ((status & ETH_INT_TXFIN) != 0)
        {
          lpc17_putreg(ETH_INT_TXFIN, LPC17_ETH_INTCLR);
          EMAC_STAT(priv, tx_finished);
        }

      if ((status & ETH_INT_TXDONE) != 0)
        {
          lpc17_putreg(ETH_INT_TXDONE, LPC17_ETH_INTCLR);
          EMAC_STAT(priv, tx_done);
          lpc17_txdone(priv);
        }

      /* Check for Wake-Up on Lan */

#if CONFIG_NET_WOL
      if ((status & ETH_INT_WKUP) != 0)
        {
          lpc17_putreg(ETH_INT_WKUP, LPC17_ETH_INTCLR);
          EMAC_STAT(priv, wol);
#         warning "Missing logic"
        }
#endif

    }

  return OK;
}

/****************************************************************************
 * Function: lpc17_txtimeout
 *
 * Description:
 *   Our TX watchdog timed out.  Called from the timer interrupt handler.
 *   The last TX never completed.  Reset the hardware and start again.
 *
 * Parameters:
 *   argc - The number of available arguments
 *   arg  - The first argument
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *   Global interrupts are disabled by the watchdog logic.
 *
 ****************************************************************************/

static void lpc17_txtimeout(int argc, uint32_t arg, ...)
{
  struct lpc17_driver_s *priv = (struct lpc17_driver_s *)arg;

  /* Increment statistics and dump debug info */

  EMAC_STAT(priv, tx_timeouts);
  
  /* Then reset the hardware */

  /* Then poll uIP for new XMIT data */

  (void)uip_poll(&priv->lp_dev, lpc17_uiptxpoll);
}

/****************************************************************************
 * Function: lpc17_polltimer
 *
 * Description:
 *   Periodic timer handler.  Called from the timer interrupt handler.
 *
 * Parameters:
 *   argc - The number of available arguments
 *   arg  - The first argument
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *   Global interrupts are disabled by the watchdog logic.
 *
 ****************************************************************************/

static void lpc17_polltimer(int argc, uint32_t arg, ...)
{
  struct lpc17_driver_s *priv = (struct lpc17_driver_s *)arg;

  /* Check if there is room in the send another TX packet.  We cannot perform
   * the TX poll if he are unable to accept another packet for transmission.
   */

  /* If so, update TCP timing states and poll uIP for new XMIT data. Hmmm..
   * might be bug here.  Does this mean if there is a transmit in progress,
   * we will missing TCP time state updates?
   */

  (void)uip_timer(&priv->lp_dev, lpc17_uiptxpoll, LPC17_POLLHSEC);

  /* Setup the watchdog poll timer again */

  (void)wd_start(priv->lp_txpoll, LPC17_WDDELAY, lpc17_polltimer, 1, arg);
}

/****************************************************************************
 * Function: lpc17_ifup
 *
 * Description:
 *   NuttX Callback: Bring up the Ethernet interface when an IP address is
 *   provided 
 *
 * Parameters:
 *   dev  - Reference to the NuttX driver state structure
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *
 ****************************************************************************/

static int lpc17_ifup(struct uip_driver_s *dev)
{
  struct lpc17_driver_s *priv = (struct lpc17_driver_s *)dev->d_private;
  uint32_t regval;
  int ret;

  ndbg("Bringing up: %d.%d.%d.%d\n",
       dev->d_ipaddr & 0xff, (dev->d_ipaddr >> 8) & 0xff,
       (dev->d_ipaddr >> 16) & 0xff, dev->d_ipaddr >> 24);

  /* Reset the Ethernet controller (again) */

  lpc17_ethreset(priv);

  /* Initialize the PHY and wait for the link to be established */

  ret = lpc17_phyinit(priv);
  if (ret != 0)
    {
      ndbg("lpc17_phyinit failed: %d\n", ret);
      return ret;
    }

  /* Configure the MAC station address */

  regval = (uint32_t)priv->lp_dev.d_mac.ether_addr_octet[1] << 8 |
           (uint32_t)priv->lp_dev.d_mac.ether_addr_octet[0];
  lpc17_putreg(regval, LPC17_ETH_SA0);

  regval = (uint32_t)priv->lp_dev.d_mac.ether_addr_octet[3] << 8 |
           (uint32_t)priv->lp_dev.d_mac.ether_addr_octet[2];
  lpc17_putreg(regval, LPC17_ETH_SA1);

  regval = (uint32_t)priv->lp_dev.d_mac.ether_addr_octet[5] << 8 |
           (uint32_t)priv->lp_dev.d_mac.ether_addr_octet[4];
  lpc17_putreg(regval, LPC17_ETH_SA2);

  /* Initialize Ethernet interface for the PHY setup */

  lpc17_macmode(priv->lp_mode);

  /* Initialize EMAC DMA memory -- descriptors, status, packet buffers, etc. */

  lpc17_txdescinit(priv);
  lpc17_rxdescinit(priv);

  /* Configure to pass all received frames */

  regval = lpc17_getreg(LPC17_ETH_MAC1);
  regval |= ETH_MAC1_PARF;
  lpc17_putreg(regval, LPC17_ETH_MAC1);

  /* Set up RX filter and configure to accept broadcast addresses, multicast
   * addresses, and perfect station address matches.
   */

  regval = ETH_RXFLCTRL_PERFEN;
#if CONFIG_NET_BROADCAST
  regval |= ETH_RXFLCTRL_BCASTEN;
#endif
#if CONFIG_NET_MULTICAST
  RXFILTERCTRL |= (ETH_RXFLCTRL_MCASTEN | ETH_RXFLCTRL_UCASTEN);
#endif
#if CONFIG_NET_HASH
  RXFILTERCTRL |= (ETH_RXFLCTRL_MCASTHASHEN | ETH_RXFLCTRL_UCASTHASHEN);
#endif
  lpc17_putreg(regval, LPC17_ETH_RXFLCTRL);

  /* Clear any pending interrupts (shouldn't be any) */

  lpc17_putreg(0xffffffff, LPC17_ETH_INTCLR);

  /* Configure interrupts.  The Ethernet interrupt was attached during one-time
   * initialization, so we only need to set the interrupt priority, configure
   * interrupts, and enable them.
   */

  /* Set the interrupt to the highest priority */

#ifdef CONFIG_ARCH_IRQPRIO
#if LM3S_NETHCONTROLLERS > 1
  (void)up_prioritize_irq(priv->irq, CONFIG_ETH_PRIORITY);
#else
  (void)up_prioritize_irq(LPC17_IRQ_ETH, CONFIG_ETH_PRIORITY);
#endif
#endif

  /* Enable Ethernet interrupts.  The way we do this depends on whether or
   * not Wakeup on Lan (WoL) has been configured.
   */

#if CONFIG_NET_WOL
  /* Configure WoL: Clear all receive filter WoLs and enable the perfect
   * match WoL interrupt.  We will wait until the Wake-up to finish
   * bringing things up.
   */

  lpc17_putreg(0xffffffff, LPC17_ETH_RXFLWOLCLR);
  lpc17_putreg(ETH_RXFLCTRL_RXFILEN, LPC17_ETH_RXRLCTRL);

  priv->lp_inten = ETH_INT_WKUP;
  lpc17_putreg(ETH_INT_WKUP, LPC17_ETH_INTEN);
#else
  /* Otherwise, enable all Rx interrupts.  Tx interrupts, SOFTINT and WoL are
   * excluded.  Tx interrupts will not be enabled until there is data to be
   * sent.
   */

  priv->lp_inten = ETH_RXINTS;
  lpc17_putreg(ETH_RXINTS, LPC17_ETH_INTEN);
#endif

  /* Set and activate a timer process */

  (void)wd_start(priv->lp_txpoll, LPC17_WDDELAY, lpc17_polltimer, 1, (uint32_t)priv);

  /* Finally, enable the Ethernet interrupt at the interrupt controller */

  priv->lp_ifup = true;
#if LM3S_NETHCONTROLLERS > 1
  up_enable_irq(priv->irq);
#else
  up_enable_irq(LPC17_IRQ_ETH);
#endif
  return OK;
}

/****************************************************************************
 * Function: lpc17_ifdown
 *
 * Description:
 *   NuttX Callback: Stop the interface.
 *
 * Parameters:
 *   dev  - Reference to the NuttX driver state structure
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *
 ****************************************************************************/

static int lpc17_ifdown(struct uip_driver_s *dev)
{
  struct lpc17_driver_s *priv = (struct lpc17_driver_s *)dev->d_private;
  irqstate_t flags;

  /* Disable the Ethernet interrupt */

  flags = irqsave();
  up_disable_irq(LPC17_IRQ_ETH);

  /* Cancel the TX poll timer and TX timeout timers */

  wd_cancel(priv->lp_txpoll);
  wd_cancel(priv->lp_txtimeout);

  /* Reset the device and mark it as down. */

  lpc17_ethreset(priv);
  priv->lp_ifup = false;
  irqrestore(flags);
  return OK;
}

/****************************************************************************
 * Function: lpc17_txavail
 *
 * Description:
 *   Driver callback invoked when new TX data is available.  This is a 
 *   stimulus perform an out-of-cycle poll and, thereby, reduce the TX
 *   latency.
 *
 * Parameters:
 *   dev  - Reference to the NuttX driver state structure
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *   Called in normal user mode
 *
 ****************************************************************************/

static int lpc17_txavail(struct uip_driver_s *dev)
{
  struct lpc17_driver_s *priv = (struct lpc17_driver_s *)dev->d_private;
  irqstate_t flags;

  /* Disable interrupts because this function may be called from interrupt
   * level processing.
   */

  flags = irqsave();

  /* Ignore the notification if the interface is not yet up */

  if (priv->lp_ifup)
    {
      /* Check if there is room in the hardware to hold another outgoing packet. */

      if (lpc17_txdesc(priv) == OK)
        {
          /* If so, then poll uIP for new XMIT data */

          (void)uip_poll(&priv->lp_dev, lpc17_uiptxpoll);
        }
    }

  irqrestore(flags);
  return OK;
}

/****************************************************************************
 * Function: lpc17_addmac
 *
 * Description:
 *   NuttX Callback: Add the specified MAC address to the hardware multicast
 *   address filtering
 *
 * Parameters:
 *   dev  - Reference to the NuttX driver state structure
 *   mac  - The MAC address to be added 
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *
 ****************************************************************************/

#ifdef CONFIG_NET_IGMP
static int lpc17_addmac(struct uip_driver_s *dev, const uint8_t *mac)
{
  struct lpc17_driver_s *priv = (struct lpc17_driver_s *)dev->d_private;

  /* Add the MAC address to the hardware multicast routing table */

#warning "Not implemented"
  return OK;
}
#endif

/****************************************************************************
 * Function: lpc17_rmmac
 *
 * Description:
 *   NuttX Callback: Remove the specified MAC address from the hardware multicast
 *   address filtering
 *
 * Parameters:
 *   dev  - Reference to the NuttX driver state structure
 *   mac  - The MAC address to be removed 
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *
 ****************************************************************************/

#ifdef CONFIG_NET_IGMP
static int lpc17_rmmac(struct uip_driver_s *dev, const uint8_t *mac)
{
  struct lpc17_driver_s *priv = (struct lpc17_driver_s *)dev->d_private;

  /* Add the MAC address to the hardware multicast routing table */

#warning "Not implemented"
  return OK;
}
#endif

/*******************************************************************************
 * Name: lpc17_showpins
 *
 * Description:
 *   Dump GPIO registers
 *
 * Parameters:
 *   None 
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *
 *******************************************************************************/

#ifdef CONFIG_LPC17_ENET_REGDEBUG
static void lpc17_showpins(void)
{
  lpc17_dumpgpio(GPIO_PORT0|GPIO_PIN0, "P0[1-15]");
  lpc17_dumpgpio(GPIO_PORT0|GPIO_PIN16, "P0[16-31]");
}
#endif

/*******************************************************************************
 * Name: lpc17_showmii
 *
 * Description:
 *   Dump PHY MII registers
 *
 * Parameters:
 *   phyaddr - The device address where the PHY was discovered
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *
 *******************************************************************************/

#if defined(CONFIG_LPC17_ENET_REGDEBUG) && defined(LPC17_HAVE_PHY)
static void lpc17_showmii(uint8_t phyaddr, const char *msg)
{
  dbg("PHY " LPC17_PHYNAME ": %s\n", msg);
  dbg("  MCR:       %04x\n", lpc17_getreg(MII_MCR));
  dbg("  MSR:       %04x\n", lpc17_getreg(MII_MSR));
  dbg("  ADVERTISE: %04x\n", lpc17_getreg(MII_ADVERTISE));
  dbg("  LPA:       %04x\n", lpc17_getreg(MII_LPA));
  dbg("  EXPANSION: %04x\n", lpc17_getreg(MII_EXPANSION));
#ifdef CONFIG_PHY_KS8721
  dbg("  10BTCR:    %04x\n", lpc17_getreg(MII_KS8721_10BTCR));
#endif
}
#endif

/****************************************************************************
 * Function: lpc17_phywrite
 *
 * Description:
 *   Write a value to an MII PHY register
 *
 * Parameters:
 *   phyaddr - The device address where the PHY was discovered
 *   regaddr - The address of the PHY register to be written
 *   phydata - The data to write to the PHY register 
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *
 ****************************************************************************/

#ifdef LPC17_HAVE_PHY
static void lpc17_phywrite(uint8_t phyaddr, uint8_t regaddr, uint16_t phydata)
{
  uint32_t regval;

  /* Set PHY address and PHY register address */

  regval = ((uint32_t)phyaddr << ETH_MADR_PHYADDR_SHIFT) |
           ((uint32_t)regaddr << ETH_MADR_REGADDR_SHIFT);
  lpc17_putreg(regval, LPC17_ETH_MADR);

  /* Set up to write */

  lpc17_putreg(ETH_MCMD_WRITE, LPC17_ETH_MCMD);

  /* Write the register data to the PHY */

  lpc17_putreg((uint32_t)phydata, LPC17_ETH_MWTD);

  /* Wait for the PHY command to complete */

  while ((lpc17_getreg(LPC17_ETH_MIND) & ETH_MIND_BUSY) != 0);
}
#endif

/****************************************************************************
 * Function: lpc17_phyread
 *
 * Description:
 *   Read a value from an MII PHY register
 *
 * Parameters:
 *   phyaddr - The device address where the PHY was discovered
 *   regaddr - The address of the PHY register to be written
 *
 * Returned Value:
 *   Data read from the PHY register
 *
 * Assumptions:
 *
 ****************************************************************************/

#ifdef LPC17_HAVE_PHY
static uint16_t lpc17_phyread(uint8_t phyaddr, uint8_t regaddr)
{
  uint32_t regval;

  lpc17_putreg(0, LPC17_ETH_MCMD);

  /* Set PHY address and PHY register address */

  regval = ((uint32_t)phyaddr << ETH_MADR_PHYADDR_SHIFT) |
           ((uint32_t)regaddr << ETH_MADR_REGADDR_SHIFT);
  lpc17_putreg(regval, LPC17_ETH_MADR);

  /* Set up to read */

  lpc17_putreg(ETH_MCMD_READ, LPC17_ETH_MCMD);

  /* Wait for the PHY command to complete */

  while ((lpc17_getreg(LPC17_ETH_MIND) & (ETH_MIND_BUSY|ETH_MIND_NVALID)) != 0);
  lpc17_putreg(0, LPC17_ETH_MCMD);

  /* Return the PHY register data */

  return (uint16_t)(lpc17_getreg(LPC17_ETH_MRDD) & ETH_MRDD_MASK);
}
#endif

/****************************************************************************
 * Function: lpc17_phyreset
 *
 * Description:
 *   Reset the PHY
 *
 * Parameters:
 *   phyaddr - The device address where the PHY was discovered
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *
 ****************************************************************************/

#ifdef LPC17_HAVE_PHY
static inline int lpc17_phyreset(uint8_t phyaddr)
{
  int32_t timeout;
  uint16_t phyreg;

  /* Reset the PHY.  Needs a minimal 50uS delay after reset. */

  lpc17_phywrite(phyaddr, MII_MCR, MII_MCR_RESET);

  /* Wait for a minimum of 50uS no matter what */

  up_udelay(50);

  /* The MCR reset bit is self-clearing.  Wait for it to be clear
   * indicating that the reset is complete.
   */

  for (timeout = MII_BIG_TIMEOUT; timeout > 0; timeout--)
    {
      phyreg = lpc17_phyread(phyaddr, MII_MCR);
      if ((phyreg & MII_MCR_RESET) == 0)
        {
          return OK;
        }
    }

  ndbg("Reset failed. MCR: %04x\n", phyreg);
  return -ETIMEDOUT;
}
#endif

/****************************************************************************
 * Function: lpc17_phyautoneg
 *
 * Description:
 *   Enable auto-negotiation.
 *
 * Parameters:
 *   phyaddr - The device address where the PHY was discovered
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *   The adverisement regiser has already been configured.
 *
 ****************************************************************************/

#if defined(LPC17_HAVE_PHY) && defined(CONFIG_PHY_AUTONEG)
static inline int lpc17_phyautoneg(uint8_t phyaddr)
{
  int32_t timeout;
  uint16_t phyreg;

  /* Start auto-negotiation */

  lpc17_phywrite(phyaddr, MII_MCR, MII_MCR_ANENABLE | MII_MCR_ANRESTART);

  /* Wait for autonegotiation to complete */

  for (timeout = MII_BIG_TIMEOUT; timeout > 0; timeout--)
    {
      /* Check if auto-negotiation has completed */

      phyreg = lpc17_phyread(phyaddr, MII_MSR);
      if ((phyreg & (MII_MSR_LINKSTATUS | MII_MSR_ANEGCOMPLETE)) == 
          (MII_MSR_LINKSTATUS | MII_MSR_ANEGCOMPLETE))
        {
          /* Yes.. return success */

          return OK;
        }
    }

  ndbg("Auto-negotiation failed. MSR: %04x\n", phyreg);
  return -ETIMEDOUT;
}
#endif

/****************************************************************************
 * Function: lpc17_phymode
 *
 * Description:
 *   Set the PHY to operate at a selected speed/duplex mode.
 *
 * Parameters:
 *   phyaddr - The device address where the PHY was discovered
 *   mode - speed/duplex mode
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *
 ****************************************************************************/

#ifdef LPC17_HAVE_PHY
static int lpc17_phymode(uint8_t phyaddr, uint8_t mode)
{
  int32_t timeout;
  uint16_t phyreg;

  /* Disable auto-negotiation and set fixed Speed and Duplex settings */

  phyreg = 0;
  if ((mode & LPC17_SPEED_MASK) ==  LPC17_SPEED_100)
    {
      phyreg = MII_MCR_SPEED100;
    }

  if ((mode & LPC17_DUPLEX_MASK) == LPC17_DUPLEX_FULL)
    {
      phyreg |= MII_MCR_FULLDPLX;
    }

  lpc17_phywrite(phyaddr, MII_MCR, phyreg);

  /* Then wait for the link to be established */

  for (timeout = MII_BIG_TIMEOUT; timeout > 0; timeout--)
    {
      phyreg = lpc17_phyread(phyaddr, MII_MSR);
      if (phyreg & MII_MSR_LINKSTATUS)
        {
          /* Yes.. return success */

          return OK;
        }
    }

  ndbg("Link failed. MSR: %04x\n", phyreg);
  return -ETIMEDOUT;
}
#endif

/****************************************************************************
 * Function: lpc17_phyinit
 *
 * Description:
 *   Initialize the PHY
 *
 * Parameters:
 *   priv - Pointer to EMAC device driver structure 
 *
 * Returned Value:
 *   None directly.  As a side-effect, it will initialize priv->lp_phyaddr
 *   and priv->lp_phymode.
 *
 * Assumptions:
 *
 ****************************************************************************/

#ifdef LPC17_HAVE_PHY
static inline int lpc17_phyinit(struct lpc17_driver_s *priv)
{
  unsigned int phyaddr;
  uint16_t phyreg;
  uint32_t regval;
  int ret;

  /* MII configuration: host clocked divided per board.h, no suppress
   * preambl,e no scan increment.
   */

  lpc17_putreg(ETH_MCFG_CLKSEL_DIV, LPC17_ETH_MCFG);
  lpc17_putreg(0, LPC17_ETH_MCMD);

  /* Enter RMII mode and select 100 MBPS support */

  lpc17_putreg(ETH_CMD_RMII, LPC17_ETH_CMD);
  lpc17_putreg(ETH_SUPP_SPEED, LPC17_ETH_SUPP);

  /* Find PHY Address.  Because controller has a pull-up and the
   * PHY have pull-down resistors on RXD lines some times the PHY
   * latches different at different addresses.
   */

  for (phyaddr = 1; phyaddr < 32; phyaddr++)
    {
       /* Check if we can see the selected device ID at this
        * PHY address.
        */

       phyreg = (unsigned int)lpc17_phyread(phyaddr, MII_PHYID1);
       if (phyreg == LPC17_PHYID1)
        {
          phyreg = lpc17_phyread(phyaddr, MII_PHYID2);
          if (phyreg  == LPC17_PHYID2)
            {
              break;
            }
        }
    }
  nvdbg("phyaddr: %d\n", phyaddr);

  /* Check if the PHY device address was found */

  if (phyaddr > 31)
    {
      /* Failed to find PHY at any location */

      return -ENODEV;
    }

  /* Save the discovered PHY device address */

  priv->lp_phyaddr = phyaddr;

  /* Reset the PHY */

  ret = lpc17_phyreset(phyaddr);
  if (ret < 0)
    {
      return ret;
    }
  lpc17_showmii(phyaddr, "After reset");

  /* Check for preamble suppression support */

  phyreg = lpc17_phyread(phyaddr, MII_MSR);
  if ((phyreg & MII_MSR_MFRAMESUPPRESS) != 0)
    {
      /* The PHY supports preamble suppression */

      regval  = lpc17_getreg(LPC17_ETH_MCFG);
      regval |= ETH_MCFG_SUPPRE;
      lpc17_putreg(regval, LPC17_ETH_MCFG);
    }

  /* Are we configured to do auto-negotiation? */

#ifdef CONFIG_PHY_AUTONEG
  /* Setup the Auto-negotiation advertisement: 100 or 10, and HD or FD */

  lpc17_phywrite(phyaddr, MII_ADVERTISE, 
                 (MII_ADVERTISE_100BASETXFULL | MII_ADVERTISE_100BASETXHALF |
                  MII_ADVERTISE_10BASETXFULL  | MII_ADVERTISE_10BASETXHALF  |
                  MII_ADVERTISE_CSMA));

  /* Then perform the auto-negotiation */

  ret = lpc17_phyautoneg(phyaddr);
  if (ret < 0)
    {
      return ret;
    }
#else
  /* Set up the fixed PHY configuration */

  ret = lpc17_phymode(phyaddr, LPC17_MODE_DEFLT);
  if (ret < 0)
    {
      return ret;
    }
#endif

  /* The link is established */

  lpc17_showmii(phyaddr, "After link established");

  /* Check configuration */

#ifdef CONFIG_PHY_KS8721
  phyreg = lpc17_phyread(phyaddr, MII_KS8721_10BTCR);

  switch (phyreg & KS8721_10BTCR_MODE_MASK)
    {
      case KS8721_10BTCR_MODE_10BTHD:  /* 10BASE-T half duplex */
        priv->lp_mode = LPC17_10BASET_HD;
        lpc17_putreg(0, LPC17_ETH_SUPP);
        break;
      case KS8721_10BTCR_MODE_100BTHD: /* 100BASE-T half duplex */
        priv->lp_mode = LPC17_100BASET_HD;
        break;
      case KS8721_10BTCR_MODE_10BTFD: /* 10BASE-T full duplex */
        priv->lp_mode = LPC17_10BASET_FD;
        lpc17_putreg(0, LPC17_ETH_SUPP);
        break;
      case KS8721_10BTCR_MODE_100BTFD: /* 100BASE-T full duplex */
        priv->lp_mode = LPC17_100BASET_FD;
        break;
      default:
        dbg("Unrecognized mode: %04x\n", phyreg);
        return -ENODEV;
    }
#else
#  warning "PHY Unknown: speed and duplex are bogus"
#endif

  ndbg("%dBase-T %s duplex\n",
       priv->lp_mode & LPC17_SPEED_MASK ==  LPC17_SPEED_100 ? 100 : 10,
       priv->lp_mode & LPC17_DUPLEX_MASK == LPC17_DUPLEX_FULL ?"full" : "half");

  /* Disable auto-configuration.  Set the fixed speed/duplex mode.
   * (probably more than little redundant).
   */

  ret = lpc17_phymode(phyaddr, LPC17_MODE_DEFLT);
  lpc17_showmii(phyaddr, "After final configuration");
  return ret;
}
#else
static inline int lpc17_phyinit(struct lpc17_driver_s *priv)
{
  priv->lp_mode = LPC17_MODE_DEFLT;
  return OK;
}
#endif

/****************************************************************************
 * Function: lpc17_txdescinit
 *
 * Description:
 *   Initialize the EMAC Tx descriptor table
 *
 * Parameters:
 *   priv - Pointer to EMAC device driver structure 
 *
 * Returned Value:
 *   None directory.
 *   As a side-effect, it will initialize priv->lp_phyaddr and
 *   priv->lp_phymode.
 *
 * Assumptions:
 *
 ****************************************************************************/