3c505.c

linux设备驱动开发详解（书代码）

/******************************************************
 *
 * open the board
 *
 ******************************************************/

static int elp_open(struct net_device *dev)
{
	elp_device *adapter;
	int retval;

	adapter = dev->priv;

	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: request to open device\n", dev->name);

	/*
	 * make sure we actually found the device
	 */
	if (adapter == NULL) {
		printk(KERN_ERR "%s: Opening a non-existent physical device\n", dev->name);
		return -EAGAIN;
	}
	/*
	 * disable interrupts on the board
	 */
	outb_control(0, dev);

	/*
	 * clear any pending interrupts
	 */
	inb_command(dev->base_addr);
	adapter_reset(dev);

	/*
	 * no receive PCBs active
	 */
	adapter->rx_active = 0;

	adapter->busy = 0;
	adapter->send_pcb_semaphore = 0;
	adapter->rx_backlog.in = 0;
	adapter->rx_backlog.out = 0;
	
	spin_lock_init(&adapter->lock);

	/*
	 * install our interrupt service routine
	 */
	if ((retval = request_irq(dev->irq, &elp_interrupt, 0, dev->name, dev))) {
		printk(KERN_ERR "%s: could not allocate IRQ%d\n", dev->name, dev->irq);
		return retval;
	}
	if ((retval = request_dma(dev->dma, dev->name))) {
		free_irq(dev->irq, dev);
		printk(KERN_ERR "%s: could not allocate DMA%d channel\n", dev->name, dev->dma);
		return retval;
	}
	adapter->dma_buffer = (void *) dma_mem_alloc(DMA_BUFFER_SIZE);
	if (!adapter->dma_buffer) {
		printk(KERN_ERR "%s: could not allocate DMA buffer\n", dev->name);
		free_dma(dev->dma);
		free_irq(dev->irq, dev);
		return -ENOMEM;
	}
	adapter->dmaing = 0;

	/*
	 * enable interrupts on the board
	 */
	outb_control(CMDE, dev);

	/*
	 * configure adapter memory: we need 10 multicast addresses, default==0
	 */
	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: sending 3c505 memory configuration command\n", dev->name);
	adapter->tx_pcb.command = CMD_CONFIGURE_ADAPTER_MEMORY;
	adapter->tx_pcb.data.memconf.cmd_q = 10;
	adapter->tx_pcb.data.memconf.rcv_q = 20;
	adapter->tx_pcb.data.memconf.mcast = 10;
	adapter->tx_pcb.data.memconf.frame = 20;
	adapter->tx_pcb.data.memconf.rcv_b = 20;
	adapter->tx_pcb.data.memconf.progs = 0;
	adapter->tx_pcb.length = sizeof(struct Memconf);
	adapter->got[CMD_CONFIGURE_ADAPTER_MEMORY] = 0;
	if (!send_pcb(dev, &adapter->tx_pcb))
		printk(KERN_ERR "%s: couldn't send memory configuration command\n", dev->name);
	else {
		unsigned long timeout = jiffies + TIMEOUT;
		while (adapter->got[CMD_CONFIGURE_ADAPTER_MEMORY] == 0 && time_before(jiffies, timeout));
		if (time_after_eq(jiffies, timeout))
			TIMEOUT_MSG(__LINE__);
	}


	/*
	 * configure adapter to receive broadcast messages and wait for response
	 */
	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: sending 82586 configure command\n", dev->name);
	adapter->tx_pcb.command = CMD_CONFIGURE_82586;
	adapter->tx_pcb.data.configure = NO_LOOPBACK | RECV_BROAD;
	adapter->tx_pcb.length = 2;
	adapter->got[CMD_CONFIGURE_82586] = 0;
	if (!send_pcb(dev, &adapter->tx_pcb))
		printk(KERN_ERR "%s: couldn't send 82586 configure command\n", dev->name);
	else {
		unsigned long timeout = jiffies + TIMEOUT;
		while (adapter->got[CMD_CONFIGURE_82586] == 0 && time_before(jiffies, timeout));
		if (time_after_eq(jiffies, timeout))
			TIMEOUT_MSG(__LINE__);
	}

	/* enable burst-mode DMA */
	/* outb(0x1, dev->base_addr + PORT_AUXDMA); */

	/*
	 * queue receive commands to provide buffering
	 */
	prime_rx(dev);
	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: %d receive PCBs active\n", dev->name, adapter->rx_active);

	/*
	 * device is now officially open!
	 */

	netif_start_queue(dev);
	return 0;
}


/******************************************************
 *
 * send a packet to the adapter
 *
 ******************************************************/

static int send_packet(struct net_device *dev, struct sk_buff *skb)
{
	elp_device *adapter = dev->priv;
	unsigned long target;
	unsigned long flags;

	/*
	 * make sure the length is even and no shorter than 60 bytes
	 */
	unsigned int nlen = (((skb->len < 60) ? 60 : skb->len) + 1) & (~1);

	if (test_and_set_bit(0, (void *) &adapter->busy)) {
		if (elp_debug >= 2)
			printk(KERN_DEBUG "%s: transmit blocked\n", dev->name);
		return FALSE;
	}

	adapter->stats.tx_bytes += nlen;
	
	/*
	 * send the adapter a transmit packet command. Ignore segment and offset
	 * and make sure the length is even
	 */
	adapter->tx_pcb.command = CMD_TRANSMIT_PACKET;
	adapter->tx_pcb.length = sizeof(struct Xmit_pkt);
	adapter->tx_pcb.data.xmit_pkt.buf_ofs
	    = adapter->tx_pcb.data.xmit_pkt.buf_seg = 0;	/* Unused */
	adapter->tx_pcb.data.xmit_pkt.pkt_len = nlen;

	if (!send_pcb(dev, &adapter->tx_pcb)) {
		adapter->busy = 0;
		return FALSE;
	}
	/* if this happens, we die */
	if (test_and_set_bit(0, (void *) &adapter->dmaing))
		printk(KERN_DEBUG "%s: tx: DMA %d in progress\n", dev->name, adapter->current_dma.direction);

	adapter->current_dma.direction = 1;
	adapter->current_dma.start_time = jiffies;

	if ((unsigned long)(skb->data + nlen) >= MAX_DMA_ADDRESS || nlen != skb->len) {
		memcpy(adapter->dma_buffer, skb->data, nlen);
		memset(adapter->dma_buffer+skb->len, 0, nlen-skb->len);
		target = isa_virt_to_bus(adapter->dma_buffer);
	}
	else {
		target = isa_virt_to_bus(skb->data);
	}
	adapter->current_dma.skb = skb;

	flags=claim_dma_lock();
	disable_dma(dev->dma);
	clear_dma_ff(dev->dma);
	set_dma_mode(dev->dma, 0x48);	/* dma memory -> io */
	set_dma_addr(dev->dma, target);
	set_dma_count(dev->dma, nlen);
	outb_control(adapter->hcr_val | DMAE | TCEN, dev);
	enable_dma(dev->dma);
	release_dma_lock(flags);
	
	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: DMA transfer started\n", dev->name);

	return TRUE;
}

/*
 *	The upper layer thinks we timed out
 */
 
static void elp_timeout(struct net_device *dev)
{
	elp_device *adapter = dev->priv;
	int stat;

	stat = inb_status(dev->base_addr);
	printk(KERN_WARNING "%s: transmit timed out, lost %s?\n", dev->name, (stat & ACRF) ? "interrupt" : "command");
	if (elp_debug >= 1)
		printk(KERN_DEBUG "%s: status %#02x\n", dev->name, stat);
	dev->trans_start = jiffies;
	adapter->stats.tx_dropped++;
	netif_wake_queue(dev);
}

/******************************************************
 *
 * start the transmitter
 *    return 0 if sent OK, else return 1
 *
 ******************************************************/

static int elp_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	unsigned long flags;
	elp_device *adapter = dev->priv;
	
	spin_lock_irqsave(&adapter->lock, flags);
	check_3c505_dma(dev);

	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: request to send packet of length %d\n", dev->name, (int) skb->len);

	netif_stop_queue(dev);
	
	/*
	 * send the packet at skb->data for skb->len
	 */
	if (!send_packet(dev, skb)) {
		if (elp_debug >= 2) {
			printk(KERN_DEBUG "%s: failed to transmit packet\n", dev->name);
		}
		spin_unlock_irqrestore(&adapter->lock, flags);
		return 1;
	}
	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: packet of length %d sent\n", dev->name, (int) skb->len);

	/*
	 * start the transmit timeout
	 */
	dev->trans_start = jiffies;

	prime_rx(dev);
	spin_unlock_irqrestore(&adapter->lock, flags);
	netif_start_queue(dev);
	return 0;
}

/******************************************************
 *
 * return statistics on the board
 *
 ******************************************************/

static struct net_device_stats *elp_get_stats(struct net_device *dev)
{
	elp_device *adapter = (elp_device *) dev->priv;

	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: request for stats\n", dev->name);

	/* If the device is closed, just return the latest stats we have,
	   - we cannot ask from the adapter without interrupts */
	if (!netif_running(dev))
		return &adapter->stats;

	/* send a get statistics command to the board */
	adapter->tx_pcb.command = CMD_NETWORK_STATISTICS;
	adapter->tx_pcb.length = 0;
	adapter->got[CMD_NETWORK_STATISTICS] = 0;
	if (!send_pcb(dev, &adapter->tx_pcb))
		printk(KERN_ERR "%s: couldn't send get statistics command\n", dev->name);
	else {
		unsigned long timeout = jiffies + TIMEOUT;
		while (adapter->got[CMD_NETWORK_STATISTICS] == 0 && time_before(jiffies, timeout));
		if (time_after_eq(jiffies, timeout)) {
			TIMEOUT_MSG(__LINE__);
			return &adapter->stats;
		}
	}

	/* statistics are now up to date */
	return &adapter->stats;
}


static void netdev_get_drvinfo(struct net_device *dev,
			       struct ethtool_drvinfo *info)
{
	strcpy(info->driver, DRV_NAME);
	strcpy(info->version, DRV_VERSION);
	sprintf(info->bus_info, "ISA 0x%lx", dev->base_addr);
}

static u32 netdev_get_msglevel(struct net_device *dev)
{
	return debug;
}

static void netdev_set_msglevel(struct net_device *dev, u32 level)
{
	debug = level;
}

static struct ethtool_ops netdev_ethtool_ops = {
	.get_drvinfo		= netdev_get_drvinfo,
	.get_msglevel		= netdev_get_msglevel,
	.set_msglevel		= netdev_set_msglevel,
};

/******************************************************
 *
 * close the board
 *
 ******************************************************/

static int elp_close(struct net_device *dev)
{
	elp_device *adapter;

	adapter = dev->priv;

	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: request to close device\n", dev->name);

	netif_stop_queue(dev);

	/* Someone may request the device statistic information even when
	 * the interface is closed. The following will update the statistics
	 * structure in the driver, so we'll be able to give current statistics.
	 */
	(void) elp_get_stats(dev);

	/*
	 * disable interrupts on the board
	 */
	outb_control(0, dev);

	/*
	 * release the IRQ
	 */
	free_irq(dev->irq, dev);

	free_dma(dev->dma);
	free_pages((unsigned long) adapter->dma_buffer, get_order(DMA_BUFFER_SIZE));

	return 0;
}


/************************************************************
 *
 * Set multicast list
 * num_addrs==0: clear mc_list
 * num_addrs==-1: set promiscuous mode
 * num_addrs>0: set mc_list
 *
 ************************************************************/

static void elp_set_mc_list(struct net_device *dev)
{
	elp_device *adapter = (elp_device *) dev->priv;
	struct dev_mc_list *dmi = dev->mc_list;
	int i;
	unsigned long flags;

	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: request to set multicast list\n", dev->name);

	spin_lock_irqsave(&adapter->lock, flags);
	
	if (!(dev->flags & (IFF_PROMISC | IFF_ALLMULTI))) {
		/* send a "load multicast list" command to the board, max 10 addrs/cmd */
		/* if num_addrs==0 the list will be cleared */
		adapter->tx_pcb.command = CMD_LOAD_MULTICAST_LIST;
		adapter->tx_pcb.length = 6 * dev->mc_count;
		for (i = 0; i < dev->mc_count; i++) {
			memcpy(adapter->tx_pcb.data.multicast[i], dmi->dmi_addr, 6);
			dmi = dmi->next;
		}
		adapter->got[CMD_LOAD_MULTICAST_LIST] = 0;
		if (!send_pcb(dev, &adapter->tx_pcb))
			printk(KERN_ERR "%s: couldn't send set_multicast command\n", dev->name);
		else {
			unsigned long timeout = jiffies + TIMEOUT;
			while (adapter->got[CMD_LOAD_MULTICAST_LIST] == 0 && time_before(jiffies, timeout));
			if (time_after_eq(jiffies, timeout)) {
				TIMEOUT_MSG(__LINE__);
			}
		}
		if (dev->mc_count)
			adapter->tx_pcb.data.configure = NO_LOOPBACK | RECV_BROAD | RECV_MULTI;
		else		/* num_addrs == 0 */
			adapter->tx_pcb.data.configure = NO_LOOPBACK | RECV_BROAD;
	} else
		adapter->tx_pcb.data.configure = NO_LOOPBACK | RECV_PROMISC;
	/*
	 * configure adapter to receive messages (as specified above)
	 * and wait for response
	 */
	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: sending 82586 configure command\n", dev->name);