synclink_gt.c

linux 内核源代码

	else
		value &= ~BIT6;
	wr_reg16(info, TCR, value);
	spin_unlock_irqrestore(&info->lock,flags);
}

#if SYNCLINK_GENERIC_HDLC

/**
 * called by generic HDLC layer when protocol selected (PPP, frame relay, etc.)
 * set encoding and frame check sequence (FCS) options
 *
 * dev       pointer to network device structure
 * encoding  serial encoding setting
 * parity    FCS setting
 *
 * returns 0 if success, otherwise error code
 */
static int hdlcdev_attach(struct net_device *dev, unsigned short encoding,
			  unsigned short parity)
{
	struct slgt_info *info = dev_to_port(dev);
	unsigned char  new_encoding;
	unsigned short new_crctype;

	/* return error if TTY interface open */
	if (info->count)
		return -EBUSY;

	DBGINFO(("%s hdlcdev_attach\n", info->device_name));

	switch (encoding)
	{
	case ENCODING_NRZ:        new_encoding = HDLC_ENCODING_NRZ; break;
	case ENCODING_NRZI:       new_encoding = HDLC_ENCODING_NRZI_SPACE; break;
	case ENCODING_FM_MARK:    new_encoding = HDLC_ENCODING_BIPHASE_MARK; break;
	case ENCODING_FM_SPACE:   new_encoding = HDLC_ENCODING_BIPHASE_SPACE; break;
	case ENCODING_MANCHESTER: new_encoding = HDLC_ENCODING_BIPHASE_LEVEL; break;
	default: return -EINVAL;
	}

	switch (parity)
	{
	case PARITY_NONE:            new_crctype = HDLC_CRC_NONE; break;
	case PARITY_CRC16_PR1_CCITT: new_crctype = HDLC_CRC_16_CCITT; break;
	case PARITY_CRC32_PR1_CCITT: new_crctype = HDLC_CRC_32_CCITT; break;
	default: return -EINVAL;
	}

	info->params.encoding = new_encoding;
	info->params.crc_type = new_crctype;

	/* if network interface up, reprogram hardware */
	if (info->netcount)
		program_hw(info);

	return 0;
}

/**
 * called by generic HDLC layer to send frame
 *
 * skb  socket buffer containing HDLC frame
 * dev  pointer to network device structure
 *
 * returns 0 if success, otherwise error code
 */
static int hdlcdev_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct slgt_info *info = dev_to_port(dev);
	struct net_device_stats *stats = hdlc_stats(dev);
	unsigned long flags;

	DBGINFO(("%s hdlc_xmit\n", dev->name));

	/* stop sending until this frame completes */
	netif_stop_queue(dev);

	/* copy data to device buffers */
	info->tx_count = skb->len;
	tx_load(info, skb->data, skb->len);

	/* update network statistics */
	stats->tx_packets++;
	stats->tx_bytes += skb->len;

	/* done with socket buffer, so free it */
	dev_kfree_skb(skb);

	/* save start time for transmit timeout detection */
	dev->trans_start = jiffies;

	/* start hardware transmitter if necessary */
	spin_lock_irqsave(&info->lock,flags);
	if (!info->tx_active)
	 	tx_start(info);
	spin_unlock_irqrestore(&info->lock,flags);

	return 0;
}

/**
 * called by network layer when interface enabled
 * claim resources and initialize hardware
 *
 * dev  pointer to network device structure
 *
 * returns 0 if success, otherwise error code
 */
static int hdlcdev_open(struct net_device *dev)
{
	struct slgt_info *info = dev_to_port(dev);
	int rc;
	unsigned long flags;

	if (!try_module_get(THIS_MODULE))
		return -EBUSY;

	DBGINFO(("%s hdlcdev_open\n", dev->name));

	/* generic HDLC layer open processing */
	if ((rc = hdlc_open(dev)))
		return rc;

	/* arbitrate between network and tty opens */
	spin_lock_irqsave(&info->netlock, flags);
	if (info->count != 0 || info->netcount != 0) {
		DBGINFO(("%s hdlc_open busy\n", dev->name));
		spin_unlock_irqrestore(&info->netlock, flags);
		return -EBUSY;
	}
	info->netcount=1;
	spin_unlock_irqrestore(&info->netlock, flags);

	/* claim resources and init adapter */
	if ((rc = startup(info)) != 0) {
		spin_lock_irqsave(&info->netlock, flags);
		info->netcount=0;
		spin_unlock_irqrestore(&info->netlock, flags);
		return rc;
	}

	/* assert DTR and RTS, apply hardware settings */
	info->signals |= SerialSignal_RTS + SerialSignal_DTR;
	program_hw(info);

	/* enable network layer transmit */
	dev->trans_start = jiffies;
	netif_start_queue(dev);

	/* inform generic HDLC layer of current DCD status */
	spin_lock_irqsave(&info->lock, flags);
	get_signals(info);
	spin_unlock_irqrestore(&info->lock, flags);
	if (info->signals & SerialSignal_DCD)
		netif_carrier_on(dev);
	else
		netif_carrier_off(dev);
	return 0;
}

/**
 * called by network layer when interface is disabled
 * shutdown hardware and release resources
 *
 * dev  pointer to network device structure
 *
 * returns 0 if success, otherwise error code
 */
static int hdlcdev_close(struct net_device *dev)
{
	struct slgt_info *info = dev_to_port(dev);
	unsigned long flags;

	DBGINFO(("%s hdlcdev_close\n", dev->name));

	netif_stop_queue(dev);

	/* shutdown adapter and release resources */
	shutdown(info);

	hdlc_close(dev);

	spin_lock_irqsave(&info->netlock, flags);
	info->netcount=0;
	spin_unlock_irqrestore(&info->netlock, flags);

	module_put(THIS_MODULE);
	return 0;
}

/**
 * called by network layer to process IOCTL call to network device
 *
 * dev  pointer to network device structure
 * ifr  pointer to network interface request structure
 * cmd  IOCTL command code
 *
 * returns 0 if success, otherwise error code
 */
static int hdlcdev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
	const size_t size = sizeof(sync_serial_settings);
	sync_serial_settings new_line;
	sync_serial_settings __user *line = ifr->ifr_settings.ifs_ifsu.sync;
	struct slgt_info *info = dev_to_port(dev);
	unsigned int flags;

	DBGINFO(("%s hdlcdev_ioctl\n", dev->name));

	/* return error if TTY interface open */
	if (info->count)
		return -EBUSY;

	if (cmd != SIOCWANDEV)
		return hdlc_ioctl(dev, ifr, cmd);

	switch(ifr->ifr_settings.type) {
	case IF_GET_IFACE: /* return current sync_serial_settings */

		ifr->ifr_settings.type = IF_IFACE_SYNC_SERIAL;
		if (ifr->ifr_settings.size < size) {
			ifr->ifr_settings.size = size; /* data size wanted */
			return -ENOBUFS;
		}

		flags = info->params.flags & (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_RXC_DPLL |
					      HDLC_FLAG_RXC_BRG    | HDLC_FLAG_RXC_TXCPIN |
					      HDLC_FLAG_TXC_TXCPIN | HDLC_FLAG_TXC_DPLL |
					      HDLC_FLAG_TXC_BRG    | HDLC_FLAG_TXC_RXCPIN);

		switch (flags){
		case (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_TXCPIN): new_line.clock_type = CLOCK_EXT; break;
		case (HDLC_FLAG_RXC_BRG    | HDLC_FLAG_TXC_BRG):    new_line.clock_type = CLOCK_INT; break;
		case (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_BRG):    new_line.clock_type = CLOCK_TXINT; break;
		case (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_RXCPIN): new_line.clock_type = CLOCK_TXFROMRX; break;
		default: new_line.clock_type = CLOCK_DEFAULT;
		}

		new_line.clock_rate = info->params.clock_speed;
		new_line.loopback   = info->params.loopback ? 1:0;

		if (copy_to_user(line, &new_line, size))
			return -EFAULT;
		return 0;

	case IF_IFACE_SYNC_SERIAL: /* set sync_serial_settings */

		if(!capable(CAP_NET_ADMIN))
			return -EPERM;
		if (copy_from_user(&new_line, line, size))
			return -EFAULT;

		switch (new_line.clock_type)
		{
		case CLOCK_EXT:      flags = HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_TXCPIN; break;
		case CLOCK_TXFROMRX: flags = HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_RXCPIN; break;
		case CLOCK_INT:      flags = HDLC_FLAG_RXC_BRG    | HDLC_FLAG_TXC_BRG;    break;
		case CLOCK_TXINT:    flags = HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_BRG;    break;
		case CLOCK_DEFAULT:  flags = info->params.flags &
					     (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_RXC_DPLL |
					      HDLC_FLAG_RXC_BRG    | HDLC_FLAG_RXC_TXCPIN |
					      HDLC_FLAG_TXC_TXCPIN | HDLC_FLAG_TXC_DPLL |
					      HDLC_FLAG_TXC_BRG    | HDLC_FLAG_TXC_RXCPIN); break;
		default: return -EINVAL;
		}

		if (new_line.loopback != 0 && new_line.loopback != 1)
			return -EINVAL;

		info->params.flags &= ~(HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_RXC_DPLL |
					HDLC_FLAG_RXC_BRG    | HDLC_FLAG_RXC_TXCPIN |
					HDLC_FLAG_TXC_TXCPIN | HDLC_FLAG_TXC_DPLL |
					HDLC_FLAG_TXC_BRG    | HDLC_FLAG_TXC_RXCPIN);
		info->params.flags |= flags;

		info->params.loopback = new_line.loopback;

		if (flags & (HDLC_FLAG_RXC_BRG | HDLC_FLAG_TXC_BRG))
			info->params.clock_speed = new_line.clock_rate;
		else
			info->params.clock_speed = 0;

		/* if network interface up, reprogram hardware */
		if (info->netcount)
			program_hw(info);
		return 0;

	default:
		return hdlc_ioctl(dev, ifr, cmd);
	}
}

/**
 * called by network layer when transmit timeout is detected
 *
 * dev  pointer to network device structure
 */
static void hdlcdev_tx_timeout(struct net_device *dev)
{
	struct slgt_info *info = dev_to_port(dev);
	struct net_device_stats *stats = hdlc_stats(dev);
	unsigned long flags;

	DBGINFO(("%s hdlcdev_tx_timeout\n", dev->name));

	stats->tx_errors++;
	stats->tx_aborted_errors++;

	spin_lock_irqsave(&info->lock,flags);
	tx_stop(info);
	spin_unlock_irqrestore(&info->lock,flags);

	netif_wake_queue(dev);
}

/**
 * called by device driver when transmit completes
 * reenable network layer transmit if stopped
 *
 * info  pointer to device instance information
 */
static void hdlcdev_tx_done(struct slgt_info *info)
{
	if (netif_queue_stopped(info->netdev))
		netif_wake_queue(info->netdev);
}

/**
 * called by device driver when frame received
 * pass frame to network layer
 *
 * info  pointer to device instance information
 * buf   pointer to buffer contianing frame data
 * size  count of data bytes in buf
 */
static void hdlcdev_rx(struct slgt_info *info, char *buf, int size)
{
	struct sk_buff *skb = dev_alloc_skb(size);
	struct net_device *dev = info->netdev;
	struct net_device_stats *stats = hdlc_stats(dev);

	DBGINFO(("%s hdlcdev_rx\n", dev->name));

	if (skb == NULL) {
		DBGERR(("%s: can't alloc skb, drop packet\n", dev->name));
		stats->rx_dropped++;
		return;
	}

	memcpy(skb_put(skb, size),buf,size);

	skb->protocol = hdlc_type_trans(skb, info->netdev);

	stats->rx_packets++;
	stats->rx_bytes += size;

	netif_rx(skb);

	info->netdev->last_rx = jiffies;
}

/**
 * called by device driver when adding device instance
 * do generic HDLC initialization
 *
 * info  pointer to device instance information
 *
 * returns 0 if success, otherwise error code
 */
static int hdlcdev_init(struct slgt_info *info)
{
	int rc;
	struct net_device *dev;
	hdlc_device *hdlc;

	/* allocate and initialize network and HDLC layer objects */

	if (!(dev = alloc_hdlcdev(info))) {
		printk(KERN_ERR "%s hdlc device alloc failure\n", info->device_name);
		return -ENOMEM;
	}

	/* for network layer reporting purposes only */
	dev->mem_start = info->phys_reg_addr;
	dev->mem_end   = info->phys_reg_addr + SLGT_REG_SIZE - 1;
	dev->irq       = info->irq_level;

	/* network layer callbacks and settings */
	dev->do_ioctl       = hdlcdev_ioctl;
	dev->open           = hdlcdev_open;
	dev->stop           = hdlcdev_close;
	dev->tx_timeout     = hdlcdev_tx_timeout;
	dev->watchdog_timeo = 10*HZ;
	dev->tx_queue_len   = 50;

	/* generic HDLC layer callbacks and settings */
	hdlc         = dev_to_hdlc(dev);
	hdlc->attach = hdlcdev_attach;
	hdlc->xmit   = hdlcdev_xmit;

	/* register objects with HDLC layer */
	if ((rc = register_hdlc_device(dev))) {
		printk(KERN_WARNING "%s:unable to register hdlc device\n",__FILE__);
		free_netdev(dev);
		return rc;
	}

	info->netdev = dev;
	return 0;
}

/**
 * called by device driver when removing device instance
 * do generic HDLC cleanup
 *
 * info  pointer to device instance information
 */
static void hdlcdev_exit(struct slgt_info *info)
{
	unregister_hdlc_device(info->netdev);
	free_netdev(info->netdev);
	info->netdev = NULL;
}

#endif /* ifdef CONFIG_HDLC */

/*
 * get async data from rx DMA buffers
 */
static void rx_async(struct slgt_info *info)
{
 	struct tty_struct *tty = info->tty;
 	struct mgsl_icount *icount = &info->icount;
	unsigned int start, end;
	unsigned char *p;
	unsigned char status;
	struct slgt_desc *bufs = info->rbufs;
	int i, count;
	int chars = 0;
	int stat;
	unsigned char ch;

	start = end = info->rbuf_current;

	while(desc_complete(bufs[end])) {
		count = desc_count(bufs[end]) - info->rbuf_index;
		p     = bufs[end].buf + info->rbuf_index;

		DBGISR(("%s rx_async count=%d\n", info->device_name, count));
		DBGDATA(info, p, count, "rx");

		for(i=0 ; i < count; i+=2, p+=2) {
			ch = *p;
			icount->rx++;

			stat = 0;

			if ((status = *(p+1) & (BIT1 + BIT0))) {
				if (status & BIT1)
					icount->parity++;
				else if (status & BIT0)
					icount->frame++;
				/* discard char if tty control flags say so */
				if (status & info->ignore_status_mask)
					continue;
				if (status & BIT1)
					stat = TTY_PARITY;
				else if (status & BIT0)
					stat = TTY_FRAME;
			}
			if (tty) {
				tty_insert_flip_char(tty, ch, stat);
				chars++;
			}
		}

		if (i < count) {
			/* receive buffer not completed */
			info->rbuf_index += i;
			mod_timer(&info->rx_timer, jiffies + 1);
			break;
		}