Logo Search packages:      
Sourcecode: linux version File versions  Download package

enet.c

/*
 * Ethernet driver for Motorola MPC8260.
 * Copyright (c) 1999 Dan Malek (dmalek@jlc.net)
 * Copyright (c) 2000 MontaVista Software Inc. (source@mvista.com)
 *    2.3.99 Updates
 *
 * I copied this from the 8xx CPM Ethernet driver, so follow the
 * credits back through that.
 *
 * This version of the driver is somewhat selectable for the different
 * processor/board combinations.  It works for the boards I know about
 * now, and should be easily modified to include others.  Some of the
 * configuration information is contained in <asm/commproc.h> and the
 * remainder is here.
 *
 * Buffer descriptors are kept in the CPM dual port RAM, and the frame
 * buffers are in the host memory.
 *
 * Right now, I am very watseful with the buffers.  I allocate memory
 * pages and then divide them into 2K frame buffers.  This way I know I
 * have buffers large enough to hold one frame within one buffer descriptor.
 * Once I get this working, I will use 64 or 128 byte CPM buffers, which
 * will be much more memory efficient and will easily handle lots of
 * small packets.
 *
 */
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/bitops.h>

#include <asm/immap_cpm2.h>
#include <asm/pgtable.h>
#include <asm/mpc8260.h>
#include <asm/uaccess.h>
#include <asm/cpm2.h>
#include <asm/irq.h>

/*
 *                      Theory of Operation
 *
 * The MPC8260 CPM performs the Ethernet processing on an SCC.  It can use
 * an aribtrary number of buffers on byte boundaries, but must have at
 * least two receive buffers to prevent constant overrun conditions.
 *
 * The buffer descriptors are allocated from the CPM dual port memory
 * with the data buffers allocated from host memory, just like all other
 * serial communication protocols.  The host memory buffers are allocated
 * from the free page pool, and then divided into smaller receive and
 * transmit buffers.  The size of the buffers should be a power of two,
 * since that nicely divides the page.  This creates a ring buffer
 * structure similar to the LANCE and other controllers.
 *
 * Like the LANCE driver:
 * The driver runs as two independent, single-threaded flows of control.  One
 * is the send-packet routine, which enforces single-threaded use by the
 * cep->tx_busy flag.  The other thread is the interrupt handler, which is
 * single threaded by the hardware and other software.
 */

/* The transmitter timeout
 */
#define TX_TIMEOUT      (2*HZ)

/* The number of Tx and Rx buffers.  These are allocated from the page
 * pool.  The code may assume these are power of two, so it is best
 * to keep them that size.
 * We don't need to allocate pages for the transmitter.  We just use
 * the skbuffer directly.
 */
#define CPM_ENET_RX_PAGES     4
#define CPM_ENET_RX_FRSIZE    2048
#define CPM_ENET_RX_FRPPG     (PAGE_SIZE / CPM_ENET_RX_FRSIZE)
#define RX_RING_SIZE          (CPM_ENET_RX_FRPPG * CPM_ENET_RX_PAGES)
#define TX_RING_SIZE          8     /* Must be power of two */
#define TX_RING_MOD_MASK      7     /*   for this to work */

/* The CPM stores dest/src/type, data, and checksum for receive packets.
 */
#define PKT_MAXBUF_SIZE       1518
#define PKT_MINBUF_SIZE       64
#define PKT_MAXBLR_SIZE       1520

/* The CPM buffer descriptors track the ring buffers.  The rx_bd_base and
 * tx_bd_base always point to the base of the buffer descriptors.  The
 * cur_rx and cur_tx point to the currently available buffer.
 * The dirty_tx tracks the current buffer that is being sent by the
 * controller.  The cur_tx and dirty_tx are equal under both completely
 * empty and completely full conditions.  The empty/ready indicator in
 * the buffer descriptor determines the actual condition.
 */
struct scc_enet_private {
      /* The saved address of a sent-in-place packet/buffer, for skfree(). */
      struct      sk_buff* tx_skbuff[TX_RING_SIZE];
      ushort      skb_cur;
      ushort      skb_dirty;

      /* CPM dual port RAM relative addresses.
      */
      cbd_t *rx_bd_base;            /* Address of Rx and Tx buffers. */
      cbd_t *tx_bd_base;
      cbd_t *cur_rx, *cur_tx;       /* The next free ring entry */
      cbd_t *dirty_tx;  /* The ring entries to be free()ed. */
      scc_t *sccp;
      struct      net_device_stats stats;
      uint  tx_full;
      spinlock_t lock;
};

static int scc_enet_open(struct net_device *dev);
static int scc_enet_start_xmit(struct sk_buff *skb, struct net_device *dev);
static int scc_enet_rx(struct net_device *dev);
static irqreturn_t scc_enet_interrupt(int irq, void *dev_id);
static int scc_enet_close(struct net_device *dev);
static struct net_device_stats *scc_enet_get_stats(struct net_device *dev);
static void set_multicast_list(struct net_device *dev);

/* These will be configurable for the SCC choice.
*/
#define CPM_ENET_BLOCK  CPM_CR_SCC1_SBLOCK
#define CPM_ENET_PAGE   CPM_CR_SCC1_PAGE
#define PROFF_ENET      PROFF_SCC1
#define SCC_ENET  0
#define SIU_INT_ENET    SIU_INT_SCC1

/* These are both board and SCC dependent....
*/
#define PD_ENET_RXD     ((uint)0x00000001)
#define PD_ENET_TXD     ((uint)0x00000002)
#define PD_ENET_TENA    ((uint)0x00000004)
#define PC_ENET_RENA    ((uint)0x00020000)
#define PC_ENET_CLSN    ((uint)0x00000004)
#define PC_ENET_TXCLK   ((uint)0x00000800)
#define PC_ENET_RXCLK   ((uint)0x00000400)
#define CMX_CLK_ROUTE   ((uint)0x25000000)
#define CMX_CLK_MASK    ((uint)0xff000000)

/* Specific to a board.
*/
#define PC_EST8260_ENET_LOOPBACK    ((uint)0x80000000)
#define PC_EST8260_ENET_SQE         ((uint)0x40000000)
#define PC_EST8260_ENET_NOTFD       ((uint)0x20000000)

static int
scc_enet_open(struct net_device *dev)
{

      /* I should reset the ring buffers here, but I don't yet know
       * a simple way to do that.
       */
      netif_start_queue(dev);
      return 0;                           /* Always succeed */
}

static int
scc_enet_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
      struct scc_enet_private *cep = (struct scc_enet_private *)dev->priv;
      volatile cbd_t    *bdp;


      /* Fill in a Tx ring entry */
      bdp = cep->cur_tx;

#ifndef final_version
      if (bdp->cbd_sc & BD_ENET_TX_READY) {
            /* Ooops.  All transmit buffers are full.  Bail out.
             * This should not happen, since cep->tx_full should be set.
             */
            printk("%s: tx queue full!.\n", dev->name);
            return 1;
      }
#endif

      /* Clear all of the status flags.
       */
      bdp->cbd_sc &= ~BD_ENET_TX_STATS;

      /* If the frame is short, tell CPM to pad it.
      */
      if (skb->len <= ETH_ZLEN)
            bdp->cbd_sc |= BD_ENET_TX_PAD;
      else
            bdp->cbd_sc &= ~BD_ENET_TX_PAD;

      /* Set buffer length and buffer pointer.
      */
      bdp->cbd_datlen = skb->len;
      bdp->cbd_bufaddr = __pa(skb->data);

      /* Save skb pointer.
      */
      cep->tx_skbuff[cep->skb_cur] = skb;

      cep->stats.tx_bytes += skb->len;
      cep->skb_cur = (cep->skb_cur+1) & TX_RING_MOD_MASK;

      spin_lock_irq(&cep->lock);

      /* Send it on its way.  Tell CPM its ready, interrupt when done,
       * its the last BD of the frame, and to put the CRC on the end.
       */
      bdp->cbd_sc |= (BD_ENET_TX_READY | BD_ENET_TX_INTR | BD_ENET_TX_LAST | BD_ENET_TX_TC);

      dev->trans_start = jiffies;

      /* If this was the last BD in the ring, start at the beginning again.
      */
      if (bdp->cbd_sc & BD_ENET_TX_WRAP)
            bdp = cep->tx_bd_base;
      else
            bdp++;

      if (bdp->cbd_sc & BD_ENET_TX_READY) {
            netif_stop_queue(dev);
            cep->tx_full = 1;
      }

      cep->cur_tx = (cbd_t *)bdp;

      spin_unlock_irq(&cep->lock);

      return 0;
}

static void
scc_enet_timeout(struct net_device *dev)
{
      struct scc_enet_private *cep = (struct scc_enet_private *)dev->priv;

      printk("%s: transmit timed out.\n", dev->name);
      cep->stats.tx_errors++;
#ifndef final_version
      {
            int   i;
            cbd_t *bdp;
            printk(" Ring data dump: cur_tx %p%s cur_rx %p.\n",
                   cep->cur_tx, cep->tx_full ? " (full)" : "",
                   cep->cur_rx);
            bdp = cep->tx_bd_base;
            printk(" Tx @base %p :\n", bdp);
            for (i = 0 ; i < TX_RING_SIZE; i++, bdp++)
                  printk("%04x %04x %08x\n",
                         bdp->cbd_sc,
                         bdp->cbd_datlen,
                         bdp->cbd_bufaddr);
            bdp = cep->rx_bd_base;
            printk(" Rx @base %p :\n", bdp);
            for (i = 0 ; i < RX_RING_SIZE; i++, bdp++)
                  printk("%04x %04x %08x\n",
                         bdp->cbd_sc,
                         bdp->cbd_datlen,
                         bdp->cbd_bufaddr);
      }
#endif
      if (!cep->tx_full)
            netif_wake_queue(dev);
}

/* The interrupt handler.
 * This is called from the CPM handler, not the MPC core interrupt.
 */
static irqreturn_t
scc_enet_interrupt(int irq, void * dev_id)
{
      struct      net_device *dev = dev_id;
      volatile struct   scc_enet_private *cep;
      volatile cbd_t    *bdp;
      ushort      int_events;
      int   must_restart;

      cep = (struct scc_enet_private *)dev->priv;

      /* Get the interrupt events that caused us to be here.
      */
      int_events = cep->sccp->scc_scce;
      cep->sccp->scc_scce = int_events;
      must_restart = 0;

      /* Handle receive event in its own function.
      */
      if (int_events & SCCE_ENET_RXF)
            scc_enet_rx(dev_id);

      /* Check for a transmit error.  The manual is a little unclear
       * about this, so the debug code until I get it figured out.  It
       * appears that if TXE is set, then TXB is not set.  However,
       * if carrier sense is lost during frame transmission, the TXE
       * bit is set, "and continues the buffer transmission normally."
       * I don't know if "normally" implies TXB is set when the buffer
       * descriptor is closed.....trial and error :-).
       */

      /* Transmit OK, or non-fatal error.  Update the buffer descriptors.
      */
      if (int_events & (SCCE_ENET_TXE | SCCE_ENET_TXB)) {
          spin_lock(&cep->lock);
          bdp = cep->dirty_tx;
          while ((bdp->cbd_sc&BD_ENET_TX_READY)==0) {
            if ((bdp==cep->cur_tx) && (cep->tx_full == 0))
                break;

            if (bdp->cbd_sc & BD_ENET_TX_HB)    /* No heartbeat */
                  cep->stats.tx_heartbeat_errors++;
            if (bdp->cbd_sc & BD_ENET_TX_LC)    /* Late collision */
                  cep->stats.tx_window_errors++;
            if (bdp->cbd_sc & BD_ENET_TX_RL)    /* Retrans limit */
                  cep->stats.tx_aborted_errors++;
            if (bdp->cbd_sc & BD_ENET_TX_UN)    /* Underrun */
                  cep->stats.tx_fifo_errors++;
            if (bdp->cbd_sc & BD_ENET_TX_CSL)   /* Carrier lost */
                  cep->stats.tx_carrier_errors++;


            /* No heartbeat or Lost carrier are not really bad errors.
             * The others require a restart transmit command.
             */
            if (bdp->cbd_sc &
                (BD_ENET_TX_LC | BD_ENET_TX_RL | BD_ENET_TX_UN)) {
                  must_restart = 1;
                  cep->stats.tx_errors++;
            }

            cep->stats.tx_packets++;

            /* Deferred means some collisions occurred during transmit,
             * but we eventually sent the packet OK.
             */
            if (bdp->cbd_sc & BD_ENET_TX_DEF)
                  cep->stats.collisions++;

            /* Free the sk buffer associated with this last transmit.
            */
            dev_kfree_skb_irq(cep->tx_skbuff[cep->skb_dirty]);
            cep->skb_dirty = (cep->skb_dirty + 1) & TX_RING_MOD_MASK;

            /* Update pointer to next buffer descriptor to be transmitted.
            */
            if (bdp->cbd_sc & BD_ENET_TX_WRAP)
                  bdp = cep->tx_bd_base;
            else
                  bdp++;

            /* I don't know if we can be held off from processing these
             * interrupts for more than one frame time.  I really hope
             * not.  In such a case, we would now want to check the
             * currently available BD (cur_tx) and determine if any
             * buffers between the dirty_tx and cur_tx have also been
             * sent.  We would want to process anything in between that
             * does not have BD_ENET_TX_READY set.
             */

            /* Since we have freed up a buffer, the ring is no longer
             * full.
             */
            if (cep->tx_full) {
                  cep->tx_full = 0;
                  if (netif_queue_stopped(dev)) {
                        netif_wake_queue(dev);
                  }
            }

            cep->dirty_tx = (cbd_t *)bdp;
          }

          if (must_restart) {
            volatile cpm_cpm2_t *cp;

            /* Some transmit errors cause the transmitter to shut
             * down.  We now issue a restart transmit.  Since the
             * errors close the BD and update the pointers, the restart
             * _should_ pick up without having to reset any of our
             * pointers either.
             */

            cp = cpmp;
            cp->cp_cpcr =
                mk_cr_cmd(CPM_ENET_PAGE, CPM_ENET_BLOCK, 0,
                              CPM_CR_RESTART_TX) | CPM_CR_FLG;
            while (cp->cp_cpcr & CPM_CR_FLG);
          }
          spin_unlock(&cep->lock);
      }

      /* Check for receive busy, i.e. packets coming but no place to
       * put them.  This "can't happen" because the receive interrupt
       * is tossing previous frames.
       */
      if (int_events & SCCE_ENET_BSY) {
            cep->stats.rx_dropped++;
            printk("SCC ENET: BSY can't happen.\n");
      }

      return IRQ_HANDLED;
}

/* During a receive, the cur_rx points to the current incoming buffer.
 * When we update through the ring, if the next incoming buffer has
 * not been given to the system, we just set the empty indicator,
 * effectively tossing the packet.
 */
static int
scc_enet_rx(struct net_device *dev)
{
      struct      scc_enet_private *cep;
      volatile cbd_t    *bdp;
      struct      sk_buff *skb;
      ushort      pkt_len;

      cep = (struct scc_enet_private *)dev->priv;

      /* First, grab all of the stats for the incoming packet.
       * These get messed up if we get called due to a busy condition.
       */
      bdp = cep->cur_rx;

for (;;) {
      if (bdp->cbd_sc & BD_ENET_RX_EMPTY)
            break;

#ifndef final_version
      /* Since we have allocated space to hold a complete frame, both
       * the first and last indicators should be set.
       */
      if ((bdp->cbd_sc & (BD_ENET_RX_FIRST | BD_ENET_RX_LAST)) !=
            (BD_ENET_RX_FIRST | BD_ENET_RX_LAST))
                  printk("CPM ENET: rcv is not first+last\n");
#endif

      /* Frame too long or too short.
      */
      if (bdp->cbd_sc & (BD_ENET_RX_LG | BD_ENET_RX_SH))
            cep->stats.rx_length_errors++;
      if (bdp->cbd_sc & BD_ENET_RX_NO)    /* Frame alignment */
            cep->stats.rx_frame_errors++;
      if (bdp->cbd_sc & BD_ENET_RX_CR)    /* CRC Error */
            cep->stats.rx_crc_errors++;
      if (bdp->cbd_sc & BD_ENET_RX_OV)    /* FIFO overrun */
            cep->stats.rx_crc_errors++;

      /* Report late collisions as a frame error.
       * On this error, the BD is closed, but we don't know what we
       * have in the buffer.  So, just drop this frame on the floor.
       */
      if (bdp->cbd_sc & BD_ENET_RX_CL) {
            cep->stats.rx_frame_errors++;
      }
      else {

            /* Process the incoming frame.
            */
            cep->stats.rx_packets++;
            pkt_len = bdp->cbd_datlen;
            cep->stats.rx_bytes += pkt_len;

            /* This does 16 byte alignment, much more than we need.
             * The packet length includes FCS, but we don't want to
             * include that when passing upstream as it messes up
             * bridging applications.
             */
            skb = dev_alloc_skb(pkt_len-4);

            if (skb == NULL) {
                  printk("%s: Memory squeeze, dropping packet.\n", dev->name);
                  cep->stats.rx_dropped++;
            }
            else {
                  skb_put(skb,pkt_len-4); /* Make room */
                  skb_copy_to_linear_data(skb,
                        (unsigned char *)__va(bdp->cbd_bufaddr),
                        pkt_len-4);
                  skb->protocol=eth_type_trans(skb,dev);
                  netif_rx(skb);
            }
      }

      /* Clear the status flags for this buffer.
      */
      bdp->cbd_sc &= ~BD_ENET_RX_STATS;

      /* Mark the buffer empty.
      */
      bdp->cbd_sc |= BD_ENET_RX_EMPTY;

      /* Update BD pointer to next entry.
      */
      if (bdp->cbd_sc & BD_ENET_RX_WRAP)
            bdp = cep->rx_bd_base;
      else
            bdp++;

   }
      cep->cur_rx = (cbd_t *)bdp;

      return 0;
}

static int
scc_enet_close(struct net_device *dev)
{
      /* Don't know what to do yet.
      */
      netif_stop_queue(dev);

      return 0;
}

static struct net_device_stats *scc_enet_get_stats(struct net_device *dev)
{
      struct scc_enet_private *cep = (struct scc_enet_private *)dev->priv;

      return &cep->stats;
}

/* Set or clear the multicast filter for this adaptor.
 * Skeleton taken from sunlance driver.
 * The CPM Ethernet implementation allows Multicast as well as individual
 * MAC address filtering.  Some of the drivers check to make sure it is
 * a group multicast address, and discard those that are not.  I guess I
 * will do the same for now, but just remove the test if you want
 * individual filtering as well (do the upper net layers want or support
 * this kind of feature?).
 */

static void set_multicast_list(struct net_device *dev)
{
      struct      scc_enet_private *cep;
      struct      dev_mc_list *dmi;
      u_char      *mcptr, *tdptr;
      volatile scc_enet_t *ep;
      int   i, j;
      cep = (struct scc_enet_private *)dev->priv;

      /* Get pointer to SCC area in parameter RAM.
      */
      ep = (scc_enet_t *)dev->base_addr;

      if (dev->flags&IFF_PROMISC) {
      
            /* Log any net taps. */
            printk("%s: Promiscuous mode enabled.\n", dev->name);
            cep->sccp->scc_psmr |= SCC_PSMR_PRO;
      } else {

            cep->sccp->scc_psmr &= ~SCC_PSMR_PRO;

            if (dev->flags & IFF_ALLMULTI) {
                  /* Catch all multicast addresses, so set the
                   * filter to all 1's.
                   */
                  ep->sen_gaddr1 = 0xffff;
                  ep->sen_gaddr2 = 0xffff;
                  ep->sen_gaddr3 = 0xffff;
                  ep->sen_gaddr4 = 0xffff;
            }
            else {
                  /* Clear filter and add the addresses in the list.
                  */
                  ep->sen_gaddr1 = 0;
                  ep->sen_gaddr2 = 0;
                  ep->sen_gaddr3 = 0;
                  ep->sen_gaddr4 = 0;

                  dmi = dev->mc_list;

                  for (i=0; i<dev->mc_count; i++) {
            
                        /* Only support group multicast for now.
                        */
                        if (!(dmi->dmi_addr[0] & 1))
                              continue;

                        /* The address in dmi_addr is LSB first,
                         * and taddr is MSB first.  We have to
                         * copy bytes MSB first from dmi_addr.
                         */
                        mcptr = (u_char *)dmi->dmi_addr + 5;
                        tdptr = (u_char *)&ep->sen_taddrh;
                        for (j=0; j<6; j++)
                              *tdptr++ = *mcptr--;

                        /* Ask CPM to run CRC and set bit in
                         * filter mask.
                         */
                        cpmp->cp_cpcr = mk_cr_cmd(CPM_ENET_PAGE,
                                    CPM_ENET_BLOCK, 0,
                                    CPM_CR_SET_GADDR) | CPM_CR_FLG;
                        /* this delay is necessary here -- Cort */
                        udelay(10);
                        while (cpmp->cp_cpcr & CPM_CR_FLG);
                  }
            }
      }
}

/* Initialize the CPM Ethernet on SCC.
 */
static int __init scc_enet_init(void)
{
      struct net_device *dev;
      struct scc_enet_private *cep;
      int i, j, err;
      uint dp_offset;
      unsigned char     *eap;
      unsigned long     mem_addr;
      bd_t        *bd;
      volatile    cbd_t       *bdp;
      volatile    cpm_cpm2_t  *cp;
      volatile    scc_t       *sccp;
      volatile    scc_enet_t  *ep;
      volatile    cpm2_map_t        *immap;
      volatile    iop_cpm2_t  *io;

      cp = cpmp;  /* Get pointer to Communication Processor */

      immap = (cpm2_map_t *)CPM_MAP_ADDR; /* and to internal registers */
      io = &immap->im_ioport;

      bd = (bd_t *)__res;

      /* Create an Ethernet device instance.
      */
      dev = alloc_etherdev(sizeof(*cep));
      if (!dev)
            return -ENOMEM;

      cep = dev->priv;
      spin_lock_init(&cep->lock);

      /* Get pointer to SCC area in parameter RAM.
      */
      ep = (scc_enet_t *)(&immap->im_dprambase[PROFF_ENET]);

      /* And another to the SCC register area.
      */
      sccp = (volatile scc_t *)(&immap->im_scc[SCC_ENET]);
      cep->sccp = (scc_t *)sccp;          /* Keep the pointer handy */

      /* Disable receive and transmit in case someone left it running.
      */
      sccp->scc_gsmrl &= ~(SCC_GSMRL_ENR | SCC_GSMRL_ENT);

      /* Configure port C and D pins for SCC Ethernet.  This
       * won't work for all SCC possibilities....it will be
       * board/port specific.
       */
      io->iop_pparc |=
            (PC_ENET_RENA | PC_ENET_CLSN | PC_ENET_TXCLK | PC_ENET_RXCLK);
      io->iop_pdirc &=
            ~(PC_ENET_RENA | PC_ENET_CLSN | PC_ENET_TXCLK | PC_ENET_RXCLK);
      io->iop_psorc &=
            ~(PC_ENET_RENA | PC_ENET_TXCLK | PC_ENET_RXCLK);
      io->iop_psorc |= PC_ENET_CLSN;

      io->iop_ppard |= (PD_ENET_RXD | PD_ENET_TXD | PD_ENET_TENA);
      io->iop_pdird |= (PD_ENET_TXD | PD_ENET_TENA);
      io->iop_pdird &= ~PD_ENET_RXD;
      io->iop_psord |= PD_ENET_TXD;
      io->iop_psord &= ~(PD_ENET_RXD | PD_ENET_TENA);

      /* Configure Serial Interface clock routing.
       * First, clear all SCC bits to zero, then set the ones we want.
       */
      immap->im_cpmux.cmx_scr &= ~CMX_CLK_MASK;
      immap->im_cpmux.cmx_scr |= CMX_CLK_ROUTE;

      /* Allocate space for the buffer descriptors in the DP ram.
       * These are relative offsets in the DP ram address space.
       * Initialize base addresses for the buffer descriptors.
       */
      dp_offset = cpm_dpalloc(sizeof(cbd_t) * RX_RING_SIZE, 8);
      ep->sen_genscc.scc_rbase = dp_offset;
      cep->rx_bd_base = (cbd_t *)cpm_dpram_addr(dp_offset);

      dp_offset = cpm_dpalloc(sizeof(cbd_t) * TX_RING_SIZE, 8);
      ep->sen_genscc.scc_tbase = dp_offset;
      cep->tx_bd_base = (cbd_t *)cpm_dpram_addr(dp_offset);

      cep->dirty_tx = cep->cur_tx = cep->tx_bd_base;
      cep->cur_rx = cep->rx_bd_base;

      ep->sen_genscc.scc_rfcr = CPMFCR_GBL | CPMFCR_EB;
      ep->sen_genscc.scc_tfcr = CPMFCR_GBL | CPMFCR_EB;

      /* Set maximum bytes per receive buffer.
       * This appears to be an Ethernet frame size, not the buffer
       * fragment size.  It must be a multiple of four.
       */
      ep->sen_genscc.scc_mrblr = PKT_MAXBLR_SIZE;

      /* Set CRC preset and mask.
      */
      ep->sen_cpres = 0xffffffff;
      ep->sen_cmask = 0xdebb20e3;

      ep->sen_crcec = 0;      /* CRC Error counter */
      ep->sen_alec = 0; /* alignment error counter */
      ep->sen_disfc = 0;      /* discard frame counter */

      ep->sen_pads = 0x8888;  /* Tx short frame pad character */
      ep->sen_retlim = 15;    /* Retry limit threshold */

      ep->sen_maxflr = PKT_MAXBUF_SIZE;   /* maximum frame length register */
      ep->sen_minflr = PKT_MINBUF_SIZE;  /* minimum frame length register */

      ep->sen_maxd1 = PKT_MAXBLR_SIZE;    /* maximum DMA1 length */
      ep->sen_maxd2 = PKT_MAXBLR_SIZE;    /* maximum DMA2 length */

      /* Clear hash tables.
      */
      ep->sen_gaddr1 = 0;
      ep->sen_gaddr2 = 0;
      ep->sen_gaddr3 = 0;
      ep->sen_gaddr4 = 0;
      ep->sen_iaddr1 = 0;
      ep->sen_iaddr2 = 0;
      ep->sen_iaddr3 = 0;
      ep->sen_iaddr4 = 0;

      /* Set Ethernet station address.
       *
       * This is supplied in the board information structure, so we
       * copy that into the controller.
       */
      eap = (unsigned char *)&(ep->sen_paddrh);
      for (i=5; i>=0; i--)
            *eap++ = dev->dev_addr[i] = bd->bi_enetaddr[i];

      ep->sen_pper = 0; /* 'cause the book says so */
      ep->sen_taddrl = 0;     /* temp address (LSB) */
      ep->sen_taddrm = 0;
      ep->sen_taddrh = 0;     /* temp address (MSB) */

      /* Now allocate the host memory pages and initialize the
       * buffer descriptors.
       */
      bdp = cep->tx_bd_base;
      for (i=0; i<TX_RING_SIZE; i++) {

            /* Initialize the BD for every fragment in the page.
            */
            bdp->cbd_sc = 0;
            bdp->cbd_bufaddr = 0;
            bdp++;
      }

      /* Set the last buffer to wrap.
      */
      bdp--;
      bdp->cbd_sc |= BD_SC_WRAP;

      bdp = cep->rx_bd_base;
      for (i=0; i<CPM_ENET_RX_PAGES; i++) {

            /* Allocate a page.
            */
            mem_addr = __get_free_page(GFP_KERNEL);
            /* BUG: no check for failure */

            /* Initialize the BD for every fragment in the page.
            */
            for (j=0; j<CPM_ENET_RX_FRPPG; j++) {
                  bdp->cbd_sc = BD_ENET_RX_EMPTY | BD_ENET_RX_INTR;
                  bdp->cbd_bufaddr = __pa(mem_addr);
                  mem_addr += CPM_ENET_RX_FRSIZE;
                  bdp++;
            }
      }

      /* Set the last buffer to wrap.
      */
      bdp--;
      bdp->cbd_sc |= BD_SC_WRAP;

      /* Let's re-initialize the channel now.  We have to do it later
       * than the manual describes because we have just now finished
       * the BD initialization.
       */
      cpmp->cp_cpcr = mk_cr_cmd(CPM_ENET_PAGE, CPM_ENET_BLOCK, 0,
                  CPM_CR_INIT_TRX) | CPM_CR_FLG;
      while (cp->cp_cpcr & CPM_CR_FLG);

      cep->skb_cur = cep->skb_dirty = 0;

      sccp->scc_scce = 0xffff;      /* Clear any pending events */

      /* Enable interrupts for transmit error, complete frame
       * received, and any transmit buffer we have also set the
       * interrupt flag.
       */
      sccp->scc_sccm = (SCCE_ENET_TXE | SCCE_ENET_RXF | SCCE_ENET_TXB);

      /* Install our interrupt handler.
      */
      request_irq(SIU_INT_ENET, scc_enet_interrupt, 0, "enet", dev);
      /* BUG: no check for failure */

      /* Set GSMR_H to enable all normal operating modes.
       * Set GSMR_L to enable Ethernet to MC68160.
       */
      sccp->scc_gsmrh = 0;
      sccp->scc_gsmrl = (SCC_GSMRL_TCI | SCC_GSMRL_TPL_48 | SCC_GSMRL_TPP_10 | SCC_GSMRL_MODE_ENET);

      /* Set sync/delimiters.
      */
      sccp->scc_dsr = 0xd555;

      /* Set processing mode.  Use Ethernet CRC, catch broadcast, and
       * start frame search 22 bit times after RENA.
       */
      sccp->scc_psmr = (SCC_PSMR_ENCRC | SCC_PSMR_NIB22);

      /* It is now OK to enable the Ethernet transmitter.
       * Unfortunately, there are board implementation differences here.
       */
      io->iop_pparc &= ~(PC_EST8260_ENET_LOOPBACK |
                        PC_EST8260_ENET_SQE | PC_EST8260_ENET_NOTFD);
      io->iop_psorc &= ~(PC_EST8260_ENET_LOOPBACK |
                        PC_EST8260_ENET_SQE | PC_EST8260_ENET_NOTFD);
      io->iop_pdirc |= (PC_EST8260_ENET_LOOPBACK |
                        PC_EST8260_ENET_SQE | PC_EST8260_ENET_NOTFD);
      io->iop_pdatc &= ~(PC_EST8260_ENET_LOOPBACK | PC_EST8260_ENET_SQE);
      io->iop_pdatc |= PC_EST8260_ENET_NOTFD;

      dev->base_addr = (unsigned long)ep;

      /* The CPM Ethernet specific entries in the device structure. */
      dev->open = scc_enet_open;
      dev->hard_start_xmit = scc_enet_start_xmit;
      dev->tx_timeout = scc_enet_timeout;
      dev->watchdog_timeo = TX_TIMEOUT;
      dev->stop = scc_enet_close;
      dev->get_stats = scc_enet_get_stats;
      dev->set_multicast_list = set_multicast_list;

      /* And last, enable the transmit and receive processing.
      */
      sccp->scc_gsmrl |= (SCC_GSMRL_ENR | SCC_GSMRL_ENT);

      err = register_netdev(dev);
      if (err) {
            free_netdev(dev);
            return err;
      }

      printk("%s: SCC ENET Version 0.1, ", dev->name);
      for (i=0; i<5; i++)
            printk("%02x:", dev->dev_addr[i]);
      printk("%02x\n", dev->dev_addr[5]);

      return 0;
}

module_init(scc_enet_init);

Generated by  Doxygen 1.6.0   Back to index