e100lpslavenet.c

内核linux2.4.20,可跟rtlinux3.2打补丁 组成实时linux系统,编译内核

	 */
#ifdef ETHDEBUG
        printk("Starting slave network transmit queue\n");
#endif
	netif_start_queue(dev);

	return 0;
}

static void 
e100_reset_tranceiver(void)
{
  /* To do: Reboot and setup slave Etrax */
}

/* Called by upper layers if they decide it took too long to complete
 * sending a packet - we need to reset and stuff.
 */

static void
e100_tx_timeout(struct net_device *dev)
{
	struct net_local *np = (struct net_local *)dev->priv;

	printk(KERN_WARNING "%s: transmit timed out, %s?\n", dev->name,
	       tx_done(dev) ? "IRQ problem" : "network cable problem");
	
	/* remember we got an error */
	
	np->stats.tx_errors++; 
	
	/* reset the TX DMA in case it has hung on something */
	
	RESET_DMA(4);
	WAIT_DMA(4);
	
	/* Reset the tranceiver. */
	
	e100_reset_tranceiver();
	
	/* and get rid of the packet that never got an interrupt */
	
	dev_kfree_skb(tx_skb);
	tx_skb = 0;
	
	/* tell the upper layers we're ok again */
	
	netif_wake_queue(dev);
}


/* This will only be invoked if the driver is _not_ in XOFF state.
 * What this means is that we need not check it, and that this
 * invariant will hold if we make sure that the netif_*_queue()
 * calls are done at the proper times.
 */

static int
e100_send_packet(struct sk_buff *skb, struct net_device *dev)
{
	struct net_local *np = (struct net_local *)dev->priv;
	int length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;
	unsigned char *buf = skb->data;
	
#ifdef ETHDEBUG
        unsigned char *temp_data_ptr = buf;
        int i;
        
	printk("Sending a packet of length %d:\n", length);
	/* dump the first bytes in the packet */
	for(i = 0; i < 8; i++) {
		printk("%d: %.2x %.2x %.2x %.2x %.2x %.2x %.2x %.2x\n", i * 8,
		       temp_data_ptr[0],temp_data_ptr[1],temp_data_ptr[2],
                       temp_data_ptr[3],temp_data_ptr[4],temp_data_ptr[5],
                       temp_data_ptr[6],temp_data_ptr[7]);
		temp_data_ptr += 8;
	}
#endif
	spin_lock_irq(&np->lock);  /* protect from tx_interrupt */

	tx_skb = skb; /* remember it so we can free it in the tx irq handler later */
	dev->trans_start = jiffies;
	
	e100_hardware_send_packet(HOST_CMD_SENDPACK, buf, length);

	/* this simple TX driver has only one send-descriptor so we're full
	 * directly. If this had a send-ring instead, we would only do this if
	 * the ring got full.
	 */

	netif_stop_queue(dev);
        
	spin_unlock_irq(&np->lock);

	return 0;
}

/*
 * The typical workload of the driver:
 *   Handle the network interface interrupts.
 */

static void
e100rx_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
	struct net_device *dev = (struct net_device *)dev_id;
	unsigned long irqbits = *R_IRQ_MASK2_RD;
        
	if(irqbits & IO_STATE(R_IRQ_MASK2_RD, dma3_eop, active)) {

		/* acknowledge the eop interrupt */

		*R_DMA_CH3_CLR_INTR = IO_STATE(R_DMA_CH3_CLR_INTR, clr_eop, do);

		/* check if one or more complete packets were indeed received */

		while(*R_DMA_CH3_FIRST != virt_to_phys(myNextRxDesc)) {
			/* Take out the buffer and give it to the OS, then
			 * allocate a new buffer to put a packet in.
			 */
			e100_rx(dev);
			((struct net_local *)dev->priv)->stats.rx_packets++;
			/* restart/continue on the channel, for safety */
			*R_DMA_CH3_CMD = IO_STATE(R_DMA_CH3_CMD, cmd, restart);
			/* clear dma channel 3 eop/descr irq bits */
			*R_DMA_CH3_CLR_INTR =
				IO_STATE(R_DMA_CH3_CLR_INTR, clr_eop, do) |
				IO_STATE(R_DMA_CH3_CLR_INTR, clr_descr, do);
			
			/* now, we might have gotten another packet
			   so we have to loop back and check if so */
		}
	}
}

/* the transmit dma channel interrupt
 *
 * this is supposed to free the skbuff which was pending during transmission,
 * and inform the kernel that we can send one more buffer
 */

static void
e100tx_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
	struct net_device *dev = (struct net_device *)dev_id;
	unsigned long irqbits = *R_IRQ_MASK2_RD;
	struct net_local *np = (struct net_local *)dev->priv;

#ifdef ETHDEBUG
        printk("We got tx interrupt\n");
#endif
	/* check for a dma4_eop interrupt */
	if(irqbits & IO_STATE(R_IRQ_MASK2_RD, dma4_descr, active)) {
		/* This protects us from concurrent execution of
		 * our dev->hard_start_xmit function above.
		 */

		spin_lock(&np->lock);
		
		/* acknowledge the eop interrupt */
                
		*R_DMA_CH4_CLR_INTR = IO_STATE(R_DMA_CH4_CLR_INTR, clr_descr, do);

                /* skip *R_DMA_CH4_FIRST == 0 test since we use d_wait... */
		if(tx_skb) {

			np->stats.tx_bytes += tx_skb->len;
			np->stats.tx_packets++;
			/* dma is ready with the transmission of the data in tx_skb, so now we can release the skb memory */
			dev_kfree_skb_irq(tx_skb);
			tx_skb = 0;
			netif_wake_queue(dev);
		} else {
			printk(KERN_WARNING "%s: tx weird interrupt\n",
                               cardname);
		}

		spin_unlock(&np->lock);
	}
}

static void
ecp_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
	struct net_device *dev = (struct net_device *)dev_id;
	struct net_local *lp = (struct net_local *)dev->priv;
	unsigned long temp, irqbits = *R_IRQ_MASK0_RD;

        /* check for ecp irq */
	if(irqbits & IO_MASK(R_IRQ_MASK0_RD, par0_ecp_cmd)) { 
		/* acknowledge by reading the bit */
		temp = *R_PAR0_STATUS_DATA;
		/* force an EOP on the incoming channel, so we'll get an rx interrupt */
		*R_SET_EOP = IO_STATE(R_SET_EOP, ch3_eop, set);
	}
}

/* We have a good packet(s), get it/them out of the buffers. */
static void
e100_rx(struct net_device *dev)
{
	struct sk_buff *skb;
	int length=0;
	int i;
	struct net_local *np = (struct net_local *)dev->priv;
	struct etrax_dma_descr *mySaveRxDesc = myNextRxDesc;
	unsigned char *skb_data_ptr;

	/* If the packet is broken down in many small packages then merge
	 * count how much space we will need to alloc with skb_alloc() for
	 * it to fit.
	 */

	while (!(myNextRxDesc->status & d_eop)) {
		length += myNextRxDesc->sw_len; /* use sw_len for the first descs */
		myNextRxDesc->status = 0;
		myNextRxDesc = phys_to_virt(myNextRxDesc->next);
	}

	length += myNextRxDesc->hw_len; /* use hw_len for the last descr */

#ifdef ETHDEBUG
	printk("Got a packet of length %d:\n", length);
	/* dump the first bytes in the packet */
	skb_data_ptr = (unsigned char *)phys_to_virt(mySaveRxDesc->buf);
	for(i = 0; i < 8; i++) {
		printk("%d: %.2x %.2x %.2x %.2x %.2x %.2x %.2x %.2x\n", i * 8,
		       skb_data_ptr[0],skb_data_ptr[1],skb_data_ptr[2],skb_data_ptr[3],
		       skb_data_ptr[4],skb_data_ptr[5],skb_data_ptr[6],skb_data_ptr[7]);
		skb_data_ptr += 8;
	}
#endif

	skb = dev_alloc_skb(length - ETHER_HEAD_LEN);
	if (!skb) {
		np->stats.rx_errors++;
		printk(KERN_NOTICE "%s: Memory squeeze, dropping packet.\n",
		       dev->name);
		return;
	}

	skb_put(skb, length - ETHER_HEAD_LEN);        /* allocate room for the packet body */
	skb_data_ptr = skb_push(skb, ETHER_HEAD_LEN); /* allocate room for the header */

#ifdef ETHDEBUG
	printk("head = 0x%x, data = 0x%x, tail = 0x%x, end = 0x%x\n",
	       skb->head, skb->data, skb->tail, skb->end);
	printk("copying packet to 0x%x.\n", skb_data_ptr);
#endif

	/* this loop can be made using max two memcpy's if optimized */

	while(mySaveRxDesc != myNextRxDesc) {
		memcpy(skb_data_ptr, phys_to_virt(mySaveRxDesc->buf),
		       mySaveRxDesc->sw_len);
		skb_data_ptr += mySaveRxDesc->sw_len;
		mySaveRxDesc = phys_to_virt(mySaveRxDesc->next);
	}

	memcpy(skb_data_ptr, phys_to_virt(mySaveRxDesc->buf),
	       mySaveRxDesc->hw_len);

	skb->dev = dev;
	skb->protocol = eth_type_trans(skb, dev);

	/* Send the packet to the upper layers */

	netif_rx(skb);

	/* Prepare for next packet */

	myNextRxDesc->status = 0;
	myPrevRxDesc = myNextRxDesc;
	myNextRxDesc = phys_to_virt(myNextRxDesc->next);

	myPrevRxDesc->ctrl |= d_eol;
	myLastRxDesc->ctrl &= ~d_eol;
	myLastRxDesc = myPrevRxDesc;

	return;
}

/* The inverse routine to net_open(). */
static int
e100_close(struct net_device *dev)
{
	struct net_local *np = (struct net_local *)dev->priv;

	printk("Closing %s.\n", dev->name);

	netif_stop_queue(dev);

	*R_IRQ_MASK0_CLR = IO_STATE(R_IRQ_MASK0_CLR, par0_ecp_cmd, clr);

	*R_IRQ_MASK2_CLR =
		IO_STATE(R_IRQ_MASK2_CLR, dma3_eop, clr) |
		IO_STATE(R_IRQ_MASK2_CLR, dma4_descr, clr);	

	/* Stop the receiver and the transmitter */

	RESET_DMA(3);
	RESET_DMA(4);

	/* Flush the Tx and disable Rx here. */

	free_irq(DMA3_RX_IRQ_NBR, (void *)dev);
	free_irq(DMA4_TX_IRQ_NBR, (void *)dev);
	free_irq(PAR0_ECP_IRQ_NBR, (void *)dev);

	free_dma(PAR1_TX_DMA_NBR);
	free_dma(PAR0_RX_DMA_NBR);

	/* Update the statistics here. */

	update_rx_stats(&np->stats);
	update_tx_stats(&np->stats);

	return 0;
}

static void
update_rx_stats(struct net_device_stats *es)
{
	unsigned long r = *R_REC_COUNTERS;
	/* update stats relevant to reception errors */
	es->rx_fifo_errors += r >> 24;            /* fifo overrun */
	es->rx_crc_errors += r & 0xff;            /* crc error */
	es->rx_frame_errors += (r >> 8) & 0xff;   /* alignment error */
	es->rx_length_errors += (r >> 16) & 0xff; /* oversized frames */
}

static void
update_tx_stats(struct net_device_stats *es)
{
	unsigned long r = *R_TR_COUNTERS;
	/* update stats relevant to transmission errors */
	es->collisions += (r & 0xff) + ((r >> 8) & 0xff); /* single_col + multiple_col */
	es->tx_errors += (r >> 24) & 0xff; /* deferred transmit frames */
}

/*
 * Get the current statistics.
 * This may be called with the card open or closed.
 */
static struct net_device_stats *
e100_get_stats(struct net_device *dev)
{
	struct net_local *lp = (struct net_local *)dev->priv;

	update_rx_stats(&lp->stats);
	update_tx_stats(&lp->stats);

	return &lp->stats;
}

/*
 * Set or clear the multicast filter for this adaptor.
 * num_addrs == -1	Promiscuous mode, receive all packets
 * num_addrs == 0	Normal mode, clear multicast list
 * num_addrs > 0	Multicast mode, receive normal and MC packets,
 *			and do best-effort filtering.
 */
static void
set_multicast_list(struct net_device *dev)
{
  /* To do */
}

void
e100_hardware_send_packet(unsigned long hostcmd, char *buf, int length)
{
  static char bogus_ecp[] = { 42, 42 };
  int i;
  

#ifdef ETHDEBUG
	printk("e100 send pack, buf 0x%x len %d\n", buf, length);
#endif
        
        host_command = hostcmd;

	/* Configure the tx dma descriptor. Desc 0 is already configured.*/

        TxDescList[1].sw_len = length;
	/* bug workaround - etrax100 needs d_wait on the descriptor _before_
	 * a descriptor containing an ECP command
	 */
	TxDescList[1].ctrl = d_wait;
	TxDescList[1].buf = virt_to_phys(buf);
	TxDescList[1].next = virt_to_phys(&TxDescList[2]);

        /* append the ecp dummy descriptor - its only purpose is to 
	 * make the receiver generate an irq due to the ecp command
	 * so the receiver knows where packets end
	 */

	TxDescList[2].sw_len = 1;
	TxDescList[2].ctrl = d_ecp | d_eol | d_int;
	TxDescList[2].buf = virt_to_phys(bogus_ecp);
        

	/* setup the dma channel and start it */

        *R_DMA_CH4_FIRST = virt_to_phys(TxDescList);
	*R_DMA_CH4_CMD = IO_STATE(R_DMA_CH4_CMD, cmd, start);
        
#ifdef ETHDEBUG         
         printk("done\n");
#endif
}

/* send a chunk of code to the slave chip to boot it. */

static void
boot_slave(unsigned char *code)
{
  int i;

#ifdef ETHDEBUG
	printk("  booting slave ETRAX...\n");
#endif
        *R_PORT_PB_DATA = 0x7F; /* Reset slave */
        udelay(15); /* Time enough to reset WAN tranciever */
        *R_PORT_PB_DATA = 0xFF; /* Reset slave */

	/* configure the tx dma data descriptor */

	TxDescList[1].sw_len = ETRAX_PAR_BOOT_LENGTH;
	TxDescList[1].ctrl = d_eol | d_int; 
                                                      
	TxDescList[1].buf = virt_to_phys(code);
	TxDescList[1].next = 0;
        
        /* setup the dma channel and start it */
 	*R_DMA_CH4_FIRST = virt_to_phys(&TxDescList[1]);
	*R_DMA_CH4_CMD = IO_STATE(R_DMA_CH4_CMD, cmd, start);

	/* wait for completion */
	while(!(*R_IRQ_READ2 & IO_MASK(R_IRQ_READ2, dma4_descr)));

	/* ack the irq */

	*R_DMA_CH4_CLR_INTR = IO_STATE(R_DMA_CH4_CLR_INTR, clr_descr, do);

#if 0
        /* manual transfer of boot code - requires dma turned off */
        for (i=0; i<ETRAX_PAR_BOOT_LENGTH; i++)
        {
          printk("  sending byte: %u value: %x\n",i,code[i]);
          while (((*R_PAR1_STATUS)&0x02) == 0); /* Wait while tr_rdy is busy*/
          *R_PAR1_CTRL_DATA = code[i];
        }
#endif

#ifdef ETHDEBUG
	printk("  done\n");
#endif
}

#ifdef ETHDEBUG
/* debug code to check the current status of PAR1 */
static void
dump_parport_status(void)
{
  unsigned long temp;
  
  printk("Parport1 status:\n");
  
  temp = (*R_PAR1_STATUS)&0xE000;
  temp = temp >> 13;
  printk("Reg mode: %u (ecp_fwd(5), ecp_rev(6))\n", temp);
  
  temp = (*R_PAR1_STATUS)&0x1000;
  temp = temp >> 12;
  printk("Reg perr: %u (ecp_rev(0))\n", temp);
  
  temp = (*R_PAR1_STATUS)&0x0800;
  temp = temp >> 11;
  printk("Reg ack: %u (inactive (1), active (0))\n", temp);
  
  temp = (*R_PAR1_STATUS)&0x0400;
  temp = temp >> 10;
  printk("Reg busy: %u (inactive (0), active (1))\n", temp);
  
  temp = (*R_PAR1_STATUS)&0x0200;
  temp = temp >> 9;
  printk("Reg fault: %u (inactive (1), active (0))\n", temp);
  
  temp = (*R_PAR1_STATUS)&0x0100;
  temp = temp >> 8;
  printk("Reg sel: %u (inactive (0), active (1), xflag(1))\n", temp);

  temp = (*R_PAR1_STATUS)&0x02;
  temp = temp >> 1;
  printk("Reg tr_rdy: %u (busy (0), ready (1))\n", temp);

}
#endif /* ETHDEBUG */

static struct net_device dev_etrax_slave_ethernet;

static int
etrax_init_module(void)
{
	struct net_device *d = &dev_etrax_slave_ethernet;

	d->init = etrax_ethernet_lpslave_init;

	if(register_netdev(d) == 0)
		return 0;
	else
		return -ENODEV;
}

module_init(etrax_init_module);