[ECOS] LAN9218 driver porting problem

["m mariga" <ma_ariga at yahoo dot co dot jp>]

Hello,

I am compelled to develop LAN device driver for SMSC LAN9218.
I am endeavouring to make it by consulting to LAN91C111 driver,but because 
there are too much differences between them it is a very hard way.
I am in a severe predicament,so I beseech you to help me.

I am making xxx_recv() routines.
I learned lan91cxx_recv() is call-backed when I call 
(sc->funs->eth_drv->recv)(sc, len) in lan91cxx_RxEvent().
But I am encountered with next problem in xxxx_RxEvent().

What value should I set cpd->rxpacket ?

In case of LAN91C111 we could get packet number from LAN91CXX_FIFO_PORTS 
Register which is set to cpd->rxpacket(please refer to excerts below),
but in LAN9218 there is no way to know packet number,just only data length 
from RX_STATUS_FIFO.

I am worried because if I could not set correct value into cpd->rxpacket,I 
suppose I could not get argument 'sg_len' correctly in xxx_recv() routine.

For example lan91cxx_recv's arguments are like next.

static void
lan91cxx_recv(struct eth_drv_sc *sc, struct eth_drv_sg *sg_list, int sg_len)

What shall I do ?
Please help me.

In the same context,also in lan91cxx_RxEvent(), it is getting packet from 
Register and comparing it to cpd->txpacket.
How shall I circumvent the problem ?

--- excerpts lan91cxx_RxEvent() begin
lan91cxx_RxEvent(struct eth_drv_sc *sc)
{
   struct lan91cxx_priv_data *cpd =
       (struct lan91cxx_priv_data *)sc->driver_private;
   unsigned short stat, len;

   DEBUG_FUNCTION();

   stat = get_reg(sc, LAN91CXX_FIFO_PORTS);
   if ( 0x8000 & stat ) {
       // Then the Rx FIFO is empty
       return;
   }

   INCR_STAT( rx_count );

   // There is an Rx Packet ready
   cpd->rxpacket = 0xff & (stat >> 8);

 |
 |

       (sc->funs->eth_drv->recv)(sc, len);

       return;
   }

--- excerpts lan91cxx_RxEvent() end

---  lan91cxx_TxEvent begin
static void
lan91cxx_TxEvent(struct eth_drv_sc *sc, int stat)
{
   unsigned short packet, ints, tcr;
   struct lan91cxx_priv_data *cpd =
       (struct lan91cxx_priv_data *)sc->driver_private;
   int success = 1;

   DEBUG_FUNCTION();

   INCR_STAT( tx_complete );

   // Ack and mask TX interrupt set
   ints = get_reg(sc, LAN91CXX_INTERRUPT) & 0xff00;
   ints |= LAN91CXX_INTERRUPT_TX_SET_ACK;
   ints &= ~LAN91CXX_INTERRUPT_TX_SET_M;
   put_reg(sc, LAN91CXX_INTERRUPT, ints);

   // Get number of completed packet and read the status word
   packet = get_reg(sc, LAN91CXX_FIFO_PORTS);

   // We do not really care about Tx failure.  Ethernet is not a reliable
   // medium.  But we do care about the TX engine stopping.
   tcr = get_reg(sc, LAN91CXX_TCR);
   if ( 0 == (LAN91CXX_TCR_TXENA & tcr) ) {
       tcr |= LAN91CXX_TCR_TXENA;
       put_reg(sc, LAN91CXX_TCR, tcr);
       success = 0; // And treat this as an error...
   }

   packet &= 0xff;

   // It certainly appears that occasionally the tx fifo tells lies; we
   // get the wrong packet number.  Freeing the one we allocated seems to
   // give correct operation.
#ifdef CYGPKG_INFRA_DEBUG
   // Then we log, OOI, the number of times we get a bad packet number
   // from the tx done fifo.
   if (cpd->txpacket != packet )
       lan91cxx_txfifo_bad++;
   else
       lan91cxx_txfifo_good++;
#endif
   // and then free the packet
   put_reg(sc, LAN91CXX_PNR, cpd->txpacket);
   put_reg(sc, LAN91CXX_MMU_COMMAND, LAN91CXX_MMU_rel_packet);

   // Ack the TX int which is supposed to clear the packet from the TX
   // completion queue.
   ints = get_reg(sc, LAN91CXX_INTERRUPT) & 0xff00;
   ints |= LAN91CXX_INTERRUPT_TX_FIFO_ACK;
   put_reg(sc, LAN91CXX_INTERRUPT, ints);

   if ( cpd->txbusy ) {
       cpd->txbusy = 0;
       (sc->funs->eth_drv->tx_done)(sc, cpd->txkey, success);
   }
}
---  lan91cxx_TxEvent end

m mariga


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