plip.c

powerpc内核mpc8241linux系统下net驱动程序

	if (rcv->skb) {
		kfree_skb(rcv->skb);
		rcv->skb = NULL;
	}
	snd->state = PLIP_PK_DONE;
	if (snd->skb) {
		dev_kfree_skb(snd->skb);
		snd->skb = NULL;
	}
	spin_unlock_irq(&nl->lock);
	if (error == HS_TIMEOUT) {
		DISABLE(dev->irq);
		synchronize_irq();
	}
	outb(PAR_INTR_OFF, PAR_CONTROL(dev));
	dev->tbusy = 1;
	nl->connection = PLIP_CN_ERROR;
	outb(0x00, PAR_DATA(dev));

	return TIMEOUT;
}

static int
plip_none(struct device *dev, struct net_local *nl,
	  struct plip_local *snd, struct plip_local *rcv)
{
	return OK;
}

/* PLIP_RECEIVE --- receive a byte(two nibbles)
   Returns OK on success, TIMEOUT on timeout */
inline static int
plip_receive(unsigned short nibble_timeout, unsigned short status_addr,
	     enum plip_nibble_state *ns_p, unsigned char *data_p)
{
	unsigned char c0, c1;
	unsigned int cx;

	switch (*ns_p) {
	case PLIP_NB_BEGIN:
		cx = nibble_timeout;
		while (1) {
			c0 = inb(status_addr);
			udelay(PLIP_DELAY_UNIT);
			if ((c0 & 0x80) == 0) {
				c1 = inb(status_addr);
				if (c0 == c1)
					break;
			}
			if (--cx == 0)
				return TIMEOUT;
		}
		*data_p = (c0 >> 3) & 0x0f;
		outb(0x10, --status_addr); /* send ACK */
		status_addr++;
		*ns_p = PLIP_NB_1;

	case PLIP_NB_1:
		cx = nibble_timeout;
		while (1) {
			c0 = inb(status_addr);
			udelay(PLIP_DELAY_UNIT);
			if (c0 & 0x80) {
				c1 = inb(status_addr);
				if (c0 == c1)
					break;
			}
			if (--cx == 0)
				return TIMEOUT;
		}
		*data_p |= (c0 << 1) & 0xf0;
		outb(0x00, --status_addr); /* send ACK */
		status_addr++;
		*ns_p = PLIP_NB_BEGIN;
	case PLIP_NB_2:
		break;
	}
	return OK;
}

/* PLIP_RECEIVE_PACKET --- receive a packet */
static int
plip_receive_packet(struct device *dev, struct net_local *nl,
		    struct plip_local *snd, struct plip_local *rcv)
{
	unsigned short status_addr = PAR_STATUS(dev);
	unsigned short nibble_timeout = nl->nibble;
	unsigned char *lbuf;

	switch (rcv->state) {
	case PLIP_PK_TRIGGER:
		DISABLE(dev->irq);
		/* Don't need to synchronize irq, as we can safely ignore it */
		outb(PAR_INTR_OFF, PAR_CONTROL(dev));
		dev->interrupt = 0;
		outb(0x01, PAR_DATA(dev)); /* send ACK */
		if (net_debug > 2)
			printk(KERN_DEBUG "%s: receive start\n", dev->name);
		rcv->state = PLIP_PK_LENGTH_LSB;
		rcv->nibble = PLIP_NB_BEGIN;

	case PLIP_PK_LENGTH_LSB:
		if (snd->state != PLIP_PK_DONE) {
			if (plip_receive(nl->trigger, status_addr,
					 &rcv->nibble, &rcv->length.b.lsb)) {
				/* collision, here dev->tbusy == 1 */
				rcv->state = PLIP_PK_DONE;
				nl->is_deferred = 1;
				nl->connection = PLIP_CN_SEND;
				queue_task(&nl->deferred, &tq_timer);
				outb(PAR_INTR_ON, PAR_CONTROL(dev));
				ENABLE(dev->irq);
				return OK;
			}
		} else {
			if (plip_receive(nibble_timeout, status_addr,
					 &rcv->nibble, &rcv->length.b.lsb))
				return TIMEOUT;
		}
		rcv->state = PLIP_PK_LENGTH_MSB;

	case PLIP_PK_LENGTH_MSB:
		if (plip_receive(nibble_timeout, status_addr,
				 &rcv->nibble, &rcv->length.b.msb))
			return TIMEOUT;
		if (rcv->length.h > dev->mtu + dev->hard_header_len
		    || rcv->length.h < 8) {
			printk(KERN_WARNING "%s: bogus packet size %d.\n", dev->name, rcv->length.h);
			return ERROR;
		}
		/* Malloc up new buffer. */
		rcv->skb = dev_alloc_skb(rcv->length.h);
		if (rcv->skb == NULL) {
			printk(KERN_ERR "%s: Memory squeeze.\n", dev->name);
			return ERROR;
		}
		skb_put(rcv->skb,rcv->length.h);
		rcv->skb->dev = dev;
		rcv->state = PLIP_PK_DATA;
		rcv->byte = 0;
		rcv->checksum = 0;

	case PLIP_PK_DATA:
		lbuf = rcv->skb->data;
		do
			if (plip_receive(nibble_timeout, status_addr,
					 &rcv->nibble, &lbuf[rcv->byte]))
				return TIMEOUT;
		while (++rcv->byte < rcv->length.h);
		do
			rcv->checksum += lbuf[--rcv->byte];
		while (rcv->byte);
		rcv->state = PLIP_PK_CHECKSUM;

	case PLIP_PK_CHECKSUM:
		if (plip_receive(nibble_timeout, status_addr,
				 &rcv->nibble, &rcv->data))
			return TIMEOUT;
		if (rcv->data != rcv->checksum) {
			nl->enet_stats.rx_crc_errors++;
			if (net_debug)
				printk(KERN_DEBUG "%s: checksum error\n", dev->name);
			return ERROR;
		}
		rcv->state = PLIP_PK_DONE;

	case PLIP_PK_DONE:
		/* Inform the upper layer for the arrival of a packet. */
		rcv->skb->protocol=eth_type_trans(rcv->skb, dev);
		netif_rx(rcv->skb);
		nl->enet_stats.rx_bytes += rcv->length.h;
		nl->enet_stats.rx_packets++;
		rcv->skb = NULL;
		if (net_debug > 2)
			printk(KERN_DEBUG "%s: receive end\n", dev->name);

		/* Close the connection. */
		outb (0x00, PAR_DATA(dev));
		spin_lock_irq(&nl->lock);
		if (snd->state != PLIP_PK_DONE) {
			nl->connection = PLIP_CN_SEND;
			spin_unlock_irq(&nl->lock);
			queue_task(&nl->immediate, &tq_immediate);
			mark_bh(IMMEDIATE_BH);
			outb(PAR_INTR_ON, PAR_CONTROL(dev));
			ENABLE(dev->irq);
			return OK;
		} else {
			nl->connection = PLIP_CN_NONE;
			spin_unlock_irq(&nl->lock);
			outb(PAR_INTR_ON, PAR_CONTROL(dev));
			ENABLE(dev->irq);
			return OK;
		}
	}
	return OK;
}

/* PLIP_SEND --- send a byte (two nibbles)
   Returns OK on success, TIMEOUT when timeout    */
inline static int
plip_send(unsigned short nibble_timeout, unsigned short data_addr,
	  enum plip_nibble_state *ns_p, unsigned char data)
{
	unsigned char c0;
	unsigned int cx;

	switch (*ns_p) {
	case PLIP_NB_BEGIN:
		outb((data & 0x0f), data_addr);
		*ns_p = PLIP_NB_1;

	case PLIP_NB_1:
		outb(0x10 | (data & 0x0f), data_addr);
		cx = nibble_timeout;
		data_addr++;
		while (1) {
			c0 = inb(data_addr);
			if ((c0 & 0x80) == 0)
				break;
			if (--cx == 0)
				return TIMEOUT;
			udelay(PLIP_DELAY_UNIT);
		}
		outb(0x10 | (data >> 4), --data_addr);
		*ns_p = PLIP_NB_2;

	case PLIP_NB_2:
		outb((data >> 4), data_addr);
		data_addr++;
		cx = nibble_timeout;
		while (1) {
			c0 = inb(data_addr);
			if (c0 & 0x80)
				break;
			if (--cx == 0)
				return TIMEOUT;
			udelay(PLIP_DELAY_UNIT);
		}
		data_addr--;
		*ns_p = PLIP_NB_BEGIN;
		return OK;
	}
	return OK;
}

/* PLIP_SEND_PACKET --- send a packet */
static int
plip_send_packet(struct device *dev, struct net_local *nl,
		 struct plip_local *snd, struct plip_local *rcv)
{
	unsigned short data_addr = PAR_DATA(dev);
	unsigned short nibble_timeout = nl->nibble;
	unsigned char *lbuf;
	unsigned char c0;
	unsigned int cx;

	if (snd->skb == NULL || (lbuf = snd->skb->data) == NULL) {
		printk(KERN_DEBUG "%s: send skb lost\n", dev->name);
		snd->state = PLIP_PK_DONE;
		snd->skb = NULL;
		return ERROR;
	}

	switch (snd->state) {
	case PLIP_PK_TRIGGER:
		if ((inb(PAR_STATUS(dev)) & 0xf8) != 0x80)
			return HS_TIMEOUT;

		/* Trigger remote rx interrupt. */
		outb(0x08, data_addr);
		cx = nl->trigger;
		while (1) {
			udelay(PLIP_DELAY_UNIT);
			spin_lock_irq(&nl->lock);
			if (nl->connection == PLIP_CN_RECEIVE) {
				spin_unlock_irq(&nl->lock);
				/* Interrupted. */
				nl->enet_stats.collisions++;
				return OK;
			}
			c0 = inb(PAR_STATUS(dev));
			if (c0 & 0x08) {
				spin_unlock_irq(&nl->lock);
				DISABLE(dev->irq);
				synchronize_irq();
				if (nl->connection == PLIP_CN_RECEIVE) {
					/* Interrupted.
					   We don't need to enable irq,
					   as it is soon disabled.    */
					/* Yes, we do. New variant of
					   {enable,disable}_irq *counts*
					   them.  -- AV  */
					ENABLE(dev->irq);
					nl->enet_stats.collisions++;
					return OK;
				}
				outb(PAR_INTR_OFF, PAR_CONTROL(dev));
				if (net_debug > 2)
					printk(KERN_DEBUG "%s: send start\n", dev->name);
				snd->state = PLIP_PK_LENGTH_LSB;
				snd->nibble = PLIP_NB_BEGIN;
				nl->timeout_count = 0;
				break;
			}
			spin_unlock_irq(&nl->lock);
			if (--cx == 0) {
				outb(0x00, data_addr);
				return HS_TIMEOUT;
			}
		}

	case PLIP_PK_LENGTH_LSB:
		if (plip_send(nibble_timeout, data_addr,
			      &snd->nibble, snd->length.b.lsb))
			return TIMEOUT;
		snd->state = PLIP_PK_LENGTH_MSB;

	case PLIP_PK_LENGTH_MSB:
		if (plip_send(nibble_timeout, data_addr,
			      &snd->nibble, snd->length.b.msb))
			return TIMEOUT;
		snd->state = PLIP_PK_DATA;
		snd->byte = 0;
		snd->checksum = 0;

	case PLIP_PK_DATA:
		do
			if (plip_send(nibble_timeout, data_addr,
				      &snd->nibble, lbuf[snd->byte]))
				return TIMEOUT;
		while (++snd->byte < snd->length.h);
		do
			snd->checksum += lbuf[--snd->byte];
		while (snd->byte);
		snd->state = PLIP_PK_CHECKSUM;

	case PLIP_PK_CHECKSUM:
		if (plip_send(nibble_timeout, data_addr,
			      &snd->nibble, snd->checksum))
			return TIMEOUT;

		nl->enet_stats.tx_bytes += snd->skb->len;
		dev_kfree_skb(snd->skb);
		nl->enet_stats.tx_packets++;
		snd->state = PLIP_PK_DONE;

	case PLIP_PK_DONE:
		/* Close the connection */
		outb (0x00, data_addr);
		snd->skb = NULL;
		if (net_debug > 2)
			printk(KERN_DEBUG "%s: send end\n", dev->name);
		nl->connection = PLIP_CN_CLOSING;
		nl->is_deferred = 1;
		queue_task(&nl->deferred, &tq_timer);
		outb(PAR_INTR_ON, PAR_CONTROL(dev));
		ENABLE(dev->irq);
		return OK;
	}
	return OK;
}

static int
plip_connection_close(struct device *dev, struct net_local *nl,
		      struct plip_local *snd, struct plip_local *rcv)
{
	spin_lock_irq(&nl->lock);
	if (nl->connection == PLIP_CN_CLOSING) {
		nl->connection = PLIP_CN_NONE;
		dev->tbusy = 0;
		mark_bh(NET_BH);
	}
	spin_unlock_irq(&nl->lock);
	if (nl->should_relinquish) {
		nl->should_relinquish = nl->port_owner = 0;
		parport_release(nl->pardev);
	}
	return OK;
}

/* PLIP_ERROR --- wait till other end settled */
static int
plip_error(struct device *dev, struct net_local *nl,
	   struct plip_local *snd, struct plip_local *rcv)
{
	unsigned char status;

	status = inb(PAR_STATUS(dev));
	if ((status & 0xf8) == 0x80) {
		if (net_debug > 2)
			printk(KERN_DEBUG "%s: reset interface.\n", dev->name);
		nl->connection = PLIP_CN_NONE;
		nl->should_relinquish = 0;
		dev->tbusy = 0;
		dev->interrupt = 0;
		outb(PAR_INTR_ON, PAR_CONTROL(dev));
		ENABLE(dev->irq);
		mark_bh(NET_BH);
	} else {
		nl->is_deferred = 1;
		queue_task(&nl->deferred, &tq_timer);
	}

	return OK;
}

/* Handle the parallel port interrupts. */
static void
plip_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
	struct device *dev = dev_id;
	struct net_local *nl;
	struct plip_local *rcv;
	unsigned char c0;

	if (dev == NULL) {
		printk(KERN_DEBUG "plip_interrupt: irq %d for unknown device.\n", irq);
		return;
	}

	nl = (struct net_local *)dev->priv;
	rcv = &nl->rcv_data;

	if (dev->interrupt)
		return;

	c0 = inb(PAR_STATUS(dev));
	if ((c0 & 0xf8) != 0xc0) {