ethernet.c

该文件是rt_linux

			myFirstTxDesc = phys_to_virt(myFirstTxDesc->descr.next);				
		}
	}

	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, dma1_eop, active)) {
		/* acknowledge the eop interrupt */

		*R_DMA_CH1_CLR_INTR = IO_STATE(R_DMA_CH1_CLR_INTR, clr_eop, do);

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

		while (*R_DMA_CH1_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_CH1_CMD = IO_STATE(R_DMA_CH1_CMD, cmd, restart);
			/* clear dma channel 1 eop/descr irq bits */
			*R_DMA_CH1_CLR_INTR =
				IO_STATE(R_DMA_CH1_CLR_INTR, clr_eop, do) |
				IO_STATE(R_DMA_CH1_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;

	/* check for a dma0_eop interrupt */
	if (irqbits & IO_STATE(R_IRQ_MASK2_RD, dma0_eop, active)) {
		/* Report all sent packets */
		do {
			/* acknowledge the eop interrupt */
			*R_DMA_CH0_CLR_INTR = IO_STATE(R_DMA_CH0_CLR_INTR, clr_eop, do);

			np->stats.tx_bytes += myFirstTxDesc->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(myFirstTxDesc->skb);
			myFirstTxDesc->skb = 0;

			if (netif_queue_stopped(dev)) {
			  	/* Queue is running, disable tx IRQ */
			  	*R_IRQ_MASK2_CLR = IO_STATE(R_IRQ_MASK2_CLR, dma0_eop, clr);		
				netif_wake_queue(dev);
			}
			myFirstTxDesc = phys_to_virt(myFirstTxDesc->descr.next);
		} while (myFirstTxDesc != phys_to_virt(*R_DMA_CH0_FIRST) &&
		         myFirstTxDesc != myNextTxDesc);
	}
}

static void
e100nw_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
	struct net_device *dev = (struct net_device *)dev_id;
	struct net_local *np = (struct net_local *)dev->priv;
	unsigned long irqbits = *R_IRQ_MASK0_RD;

	/* check for underrun irq */
	if (irqbits & IO_STATE(R_IRQ_MASK0_RD, underrun, active)) { 
		*R_NETWORK_TR_CTRL = IO_STATE(R_NETWORK_TR_CTRL, clr_error, clr);
		np->stats.tx_errors++;
		D(printk("ethernet receiver underrun!\n"));
	}

	/* check for overrun irq */
	if (irqbits & IO_STATE(R_IRQ_MASK0_RD, overrun, active)) { 
		update_rx_stats(&np->stats); /* this will ack the irq */
		D(printk("ethernet receiver overrun!\n"));
	}
	/* check for excessive collision irq */
	if (irqbits & IO_STATE(R_IRQ_MASK0_RD, excessive_col, active)) { 
		*R_NETWORK_TR_CTRL = IO_STATE(R_NETWORK_TR_CTRL, clr_error, clr);
		np->stats.tx_errors++;
		D(printk("ethernet excessive collisions!\n"));
	}
}

/* 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;
	struct net_local *np = (struct net_local *)dev->priv;
	unsigned char *skb_data_ptr;
#ifdef ETHDEBUG
	int i;
#endif

	if (!led_active && time_after(jiffies, led_next_time)) {
		/* light the network leds depending on the current speed. */
		e100_set_network_leds(NETWORK_ACTIVITY);

		/* Set the earliest time we may clear the LED */
		led_next_time = jiffies + NET_FLASH_TIME;
		led_active = 1;
		mod_timer(&clear_led_timer, jiffies + HZ/10);
	}

	length = myNextRxDesc->descr.hw_len - 4;
	((struct net_local *)dev->priv)->stats.rx_bytes += length;

#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(myNextRxDesc->descr.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

	if (length < RX_COPYBREAK) {
		/* Small packet, copy data */
		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
          
		memcpy(skb_data_ptr, phys_to_virt(myNextRxDesc->descr.buf), length);
	}
	else {
		/* Large packet, send directly to upper layers and allocate new memory */		 
		skb = myNextRxDesc->skb;
		skb_put(skb, length);
		myNextRxDesc->skb = dev_alloc_skb(MAX_MEDIA_DATA_SIZE);
		myNextRxDesc->descr.buf = virt_to_phys(myNextRxDesc->skb->data);
	}

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

	rx_queue_len++;

	/* Check if descriptors should be returned */
	if (rx_queue_len == RX_QUEUE_THRESHOLD) {
		flush_etrax_cache();
		myPrevRxDesc->descr.ctrl |= d_eol;
		myLastRxDesc->descr.ctrl &= ~d_eol;
		myLastRxDesc = myPrevRxDesc;
		rx_queue_len = 0;
	}
}

/* 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_NETWORK_GEN_CONFIG =
		IO_STATE(R_NETWORK_GEN_CONFIG, phy,    mii_clk) |
		IO_STATE(R_NETWORK_GEN_CONFIG, enable, off);
	
	*R_IRQ_MASK0_CLR =
		IO_STATE(R_IRQ_MASK0_CLR, overrun, clr) |
		IO_STATE(R_IRQ_MASK0_CLR, underrun, clr) |
		IO_STATE(R_IRQ_MASK0_CLR, excessive_col, clr);
	
	*R_IRQ_MASK2_CLR =
		IO_STATE(R_IRQ_MASK2_CLR, dma0_descr, clr) |
		IO_STATE(R_IRQ_MASK2_CLR, dma0_eop, clr) |
		IO_STATE(R_IRQ_MASK2_CLR, dma1_descr, clr) |
		IO_STATE(R_IRQ_MASK2_CLR, dma1_eop, clr);

	/* Stop the receiver and the transmitter */

	RESET_DMA(NETWORK_TX_DMA_NBR);
	RESET_DMA(NETWORK_RX_DMA_NBR);

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

	free_irq(NETWORK_DMA_RX_IRQ_NBR, (void *)dev);
	free_irq(NETWORK_DMA_TX_IRQ_NBR, (void *)dev);
	free_irq(NETWORK_STATUS_IRQ_NBR, (void *)dev);

	free_dma(NETWORK_TX_DMA_NBR);
	free_dma(NETWORK_RX_DMA_NBR);

	/* Update the statistics here. */

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

	return 0;
}

static int
e100_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
	/* Maybe default should return -EINVAL instead? */
	switch (cmd) {
		case SET_ETH_SPEED_10:                  /* 10 Mbps */
			e100_set_speed(10);
			break;
		case SET_ETH_SPEED_100:                /* 100 Mbps */
			e100_set_speed(100);
			break;
		case SET_ETH_SPEED_AUTO:              /* Auto negotiate speed */
			e100_set_speed(0);
			break;
		case SET_ETH_DUPLEX_HALF:              /* Hhalf duplex. */
			e100_set_duplex(half);
			break;
		case SET_ETH_DUPLEX_FULL:              /* Full duplex. */
			e100_set_duplex(full);
			break;
		case SET_ETH_DUPLEX_AUTO:             /* Autonegotiate duplex*/
			e100_set_duplex(autoneg);
			break;
		default: /* Auto neg */
			e100_set_speed(0);
			e100_set_duplex(autoneg);
			break;
	}
	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 += IO_EXTRACT(R_REC_COUNTERS, congestion, r);
	es->rx_crc_errors += IO_EXTRACT(R_REC_COUNTERS, crc_error, r);
	es->rx_frame_errors += IO_EXTRACT(R_REC_COUNTERS, alignment_error, r);
	es->rx_length_errors += IO_EXTRACT(R_REC_COUNTERS, oversize, r);
}

static void
update_tx_stats(struct net_device_stats *es)
{
	unsigned long r = *R_TR_COUNTERS;
	/* update stats relevant to transmission errors */
	es->collisions +=
		IO_EXTRACT(R_TR_COUNTERS, single_col, r) +
		IO_EXTRACT(R_TR_COUNTERS, multiple_col, r);
	es->tx_errors += IO_EXTRACT(R_TR_COUNTERS, deferred, r);
}

/*
 * 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)
{
	int num_addr = dev->mc_count;
	unsigned long int lo_bits;
	unsigned long int hi_bits;
	if (dev->flags & IFF_PROMISC)
	{
		/* promiscuous mode */
		lo_bits = 0xfffffffful;
		hi_bits = 0xfffffffful;

		/* Enable individual receive */
		SETS(network_rec_config_shadow, R_NETWORK_REC_CONFIG, individual, receive);
		*R_NETWORK_REC_CONFIG = network_rec_config_shadow;
	} else if (dev->flags & IFF_ALLMULTI) {
		/* enable all multicasts */
		lo_bits = 0xfffffffful;
		hi_bits = 0xfffffffful;

		/* Disable individual receive */
		SETS(network_rec_config_shadow, R_NETWORK_REC_CONFIG, individual, discard);
		*R_NETWORK_REC_CONFIG =  network_rec_config_shadow;
	} else if (num_addr == 0) {
		/* Normal, clear the mc list */
		lo_bits = 0x00000000ul;
		hi_bits = 0x00000000ul;

		/* Disable individual receive */
		SETS(network_rec_config_shadow, R_NETWORK_REC_CONFIG, individual, discard);
		*R_NETWORK_REC_CONFIG =  network_rec_config_shadow;
	} else {
		/* MC mode, receive normal and MC packets */
		char hash_ix;
		struct dev_mc_list *dmi = dev->mc_list;
		int i;
		char *baddr;
		lo_bits = 0x00000000ul;
		hi_bits = 0x00000000ul;
		for (i=0; i<num_addr; i++) {
			/* Calculate the hash index for the GA registers */
			
			hash_ix = 0;
			baddr = dmi->dmi_addr;
			hash_ix ^= (*baddr) & 0x3f;
			hash_ix ^= ((*baddr) >> 6) & 0x03;
			++baddr;
			hash_ix ^= ((*baddr) << 2) & 0x03c;
			hash_ix ^= ((*baddr) >> 4) & 0xf;
			++baddr;
			hash_ix ^= ((*baddr) << 4) & 0x30;
			hash_ix ^= ((*baddr) >> 2) & 0x3f;
			++baddr;
			hash_ix ^= (*baddr) & 0x3f;
			hash_ix ^= ((*baddr) >> 6) & 0x03;
			++baddr;
			hash_ix ^= ((*baddr) << 2) & 0x03c;
			hash_ix ^= ((*baddr) >> 4) & 0xf;
			++baddr;
			hash_ix ^= ((*baddr) << 4) & 0x30;
			hash_ix ^= ((*baddr) >> 2) & 0x3f;
			
			hash_ix &= 0x3f;
			
			if (hash_ix > 32) {
				hi_bits |= (1 << (hash_ix-32));
			}
			else {
				lo_bits |= (1 << hash_ix);
			}
			dmi = dmi->next;
		}
		/* Disable individual receive */
		SETS(network_rec_config_shadow, R_NETWORK_REC_CONFIG, individual, discard);
		*R_NETWORK_REC_CONFIG = network_rec_config_shadow;
	}
	*R_NETWORK_GA_0 = lo_bits;
	*R_NETWORK_GA_1 = hi_bits;
}

void
e100_hardware_send_packet(char *buf, int length)
{
	D(printk("e100 send pack, buf 0x%x len %d\n", buf, length));

	if (!led_active && time_after(jiffies, led_next_time)) {
		/* light the network leds depending on the current speed. */
		e100_set_network_leds(NETWORK_ACTIVITY);

		/* Set the earliest time we may clear the LED */
		led_next_time = jiffies + NET_FLASH_TIME;
		led_active = 1;
		mod_timer(&clear_led_timer, jiffies + HZ/10);
	}

	/* configure the tx dma descriptor */
	myNextTxDesc->descr.sw_len = length;
	myNextTxDesc->descr.ctrl = d_eop | d_eol | d_wait;
	myNextTxDesc->descr.buf = virt_to_phys(buf);

        /* Move end of list */
        myLastTxDesc->descr.ctrl &= ~d_eol;
        myLastTxDesc = myNextTxDesc;

	/* Restart DMA channel */
	*R_DMA_CH0_CMD = IO_STATE(R_DMA_CH0_CMD, cmd, restart);
}

static void
e100_clear_network_leds(unsigned long dummy)
{
	if (led_active && time_after(jiffies, led_next_time)) {
		e100_set_network_leds(NO_NETWORK_ACTIVITY);

		/* Set the earliest time we may set the LED */
		led_next_time = jiffies + NET_FLASH_PAUSE;
		led_active = 0;
	}
}

static void
e100_set_network_leds(int active)
{
#if defined(CONFIG_ETRAX_NETWORK_LED_ON_WHEN_LINK)
	int light_leds = (active == NO_NETWORK_ACTIVITY);
#elif defined(CONFIG_ETRAX_NETWORK_LED_ON_WHEN_ACTIVITY)
	int light_leds = (active == NETWORK_ACTIVITY);
#else
#error "Define either CONFIG_ETRAX_NETWORK_LED_ON_WHEN_LINK or CONFIG_ETRAX_NETWORK_LED_ON_WHEN_ACTIVITY"
#endif

	if (!current_speed) {
		/* Make LED red, link is down */
		LED_NETWORK_SET(LED_RED);
	}
	else if (light_leds) {
		if (current_speed == 10) {
			LED_NETWORK_SET(LED_ORANGE);
		} else {
			LED_NETWORK_SET(LED_GREEN);
		}
	}
	else {
		LED_NETWORK_SET(LED_OFF);
	}
}

static struct net_device dev_etrax_ethernet;  /* only got one */

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

	d->init = etrax_ethernet_init;

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

module_init(etrax_init_module);