dscc4.c

一个2.4.21版本的嵌入式linux内核

			dev_kfree_skb(*skbuff);
		}
		skbuff++;
		rx_fd++;
	}
}

inline int try_get_rx_skb(struct dscc4_dev_priv *dpriv, struct net_device *dev)
{
	unsigned int dirty = dpriv->rx_dirty%RX_RING_SIZE;
	struct RxFD *rx_fd = dpriv->rx_fd + dirty;
	const int len = RX_MAX(HDLC_MAX_MRU);
	struct sk_buff *skb;
	int ret = 0;

	skb = dev_alloc_skb(len);
	dpriv->rx_skbuff[dirty] = skb;
	if (skb) {
	skb->dev = dev;
		skb->protocol = htons(ETH_P_HDLC);
	skb->mac.raw = skb->data;
		rx_fd->data = pci_map_single(dpriv->pci_priv->pdev, skb->data,
					     len, PCI_DMA_FROMDEVICE);
	} else {
		rx_fd->data = (u32) NULL;
		ret = -1;
	}
	return ret;
}

/*
 * IRQ/thread/whatever safe
 */
static int dscc4_wait_ack_cec(struct dscc4_dev_priv *dpriv,
			      struct net_device *dev, char *msg)
{
	s8 i = 0;

	do {
		if (!(scc_readl_star(dpriv, dev) & SccBusy)) {
			printk(KERN_DEBUG "%s: %s ack (%d try)\n", dev->name,
			       msg, i);
			goto done;
		}
		set_current_state(TASK_UNINTERRUPTIBLE);
		schedule_timeout(10);
		rmb();
	} while (++i > 0);
	printk(KERN_ERR "%s: %s timeout\n", dev->name, msg);
done:
	return (i >= 0) ? i : -EAGAIN;
}

static int dscc4_do_action(struct net_device *dev, char *msg)
{
	unsigned long ioaddr = dev->base_addr;
	s16 i = 0;

	writel(Action, ioaddr + GCMDR);
	ioaddr += GSTAR;
	do {
		u32 state = readl(ioaddr);

		if (state & ArAck) {
			printk(KERN_DEBUG "%s: %s ack\n", dev->name, msg);
			writel(ArAck, ioaddr);
			goto done;
		} else if (state & Arf) {
			printk(KERN_ERR "%s: %s failed\n", dev->name, msg);
			writel(Arf, ioaddr);
			i = -1;
			goto done;
	}
		rmb();
	} while (++i > 0);
	printk(KERN_ERR "%s: %s timeout\n", dev->name, msg);
done:
	return i;
}

static inline int dscc4_xpr_ack(struct dscc4_dev_priv *dpriv)
{
	int cur = dpriv->iqtx_current%IRQ_RING_SIZE;
	s8 i = 0;

	do {
		if (!(dpriv->flags & (NeedIDR | NeedIDT)) ||
		    (dpriv->iqtx[cur] & Xpr))
			break;
		smp_rmb();
		set_current_state(TASK_UNINTERRUPTIBLE);
		schedule_timeout(10);
	} while (++i > 0);

	return (i >= 0 ) ? i : -EAGAIN;
}

/* Requires protection against interrupt */
static void dscc4_rx_reset(struct dscc4_dev_priv *dpriv, struct net_device *dev)
{
	/* Cf errata DS5 p.6 */
	writel(0x00000000, dev->base_addr + CH0LRDA + dpriv->dev_id*4);
	scc_writel(~PowerUp & scc_readl(dpriv, CCR0), dpriv, dev, CCR0);
	readl(dev->base_addr + CH0LRDA + dpriv->dev_id*4);
	writel(MTFi|Rdr, dev->base_addr + dpriv->dev_id*0x0c + CH0CFG);
	writel(Action, dev->base_addr + GCMDR);
}

static void dscc4_tx_reset(struct dscc4_dev_priv *dpriv, struct net_device *dev)
{
	u16 i = 0;

	/* Cf errata DS5 p.7 */
	scc_writel(~PowerUp & scc_readl(dpriv, CCR0), dpriv, dev, CCR0);
	scc_writel(0x00050000, dpriv, dev, CCR2);
	/*
	 * Must be longer than the time required to fill the fifo.
	 */
	while (!dscc4_tx_quiescent(dpriv, dev) && ++i) {
		udelay(1);
		wmb();
	}

	writel(MTFi|Rdt, dev->base_addr + dpriv->dev_id*0x0c + CH0CFG);
	if (dscc4_do_action(dev, "Rdt") < 0)
		printk(KERN_ERR "%s: Tx reset failed\n", dev->name);
}

/* TODO: (ab)use this function to refill a completely depleted RX ring. */
static inline void dscc4_rx_skb(struct dscc4_dev_priv *dpriv,
				struct net_device *dev)
{
	struct RxFD *rx_fd = dpriv->rx_fd + dpriv->rx_current%RX_RING_SIZE;
	struct net_device_stats *stats = &dpriv->hdlc.stats;
	struct pci_dev *pdev = dpriv->pci_priv->pdev;
	struct sk_buff *skb;
	int pkt_len;

	skb = dpriv->rx_skbuff[dpriv->rx_current++%RX_RING_SIZE];
	if (!skb) {
		printk(KERN_DEBUG "%s: skb=0 (%s)\n", dev->name, __FUNCTION__);
		goto refill;
	}
	pkt_len = TO_SIZE(rx_fd->state2);
	pci_dma_sync_single(pdev, rx_fd->data, pkt_len, PCI_DMA_FROMDEVICE);
	pci_unmap_single(pdev, rx_fd->data, RX_MAX(HDLC_MAX_MRU), PCI_DMA_FROMDEVICE);
	if ((skb->data[--pkt_len] & FrameOk) == FrameOk) {
		stats->rx_packets++;
		stats->rx_bytes += pkt_len;
		skb_put(skb, pkt_len);
		skb->dev->last_rx = jiffies;
		netif_rx(skb);
	} else {
		if (skb->data[pkt_len] & FrameRdo)
			stats->rx_fifo_errors++;
		else if (!(skb->data[pkt_len] | ~FrameCrc))
			stats->rx_crc_errors++;
		else if (!(skb->data[pkt_len] | ~(FrameVfr | FrameRab)))
			stats->rx_length_errors++;
		else
			stats->rx_errors++;
		dev_kfree_skb_irq(skb);
	}
refill:
	while ((dpriv->rx_dirty - dpriv->rx_current) % RX_RING_SIZE) {
		if (try_get_rx_skb(dpriv, dev) < 0)
			break;
		dpriv->rx_dirty++;
	}
	dscc4_rx_update(dpriv, dev);
	rx_fd->state2 = 0x00000000;
	rx_fd->end = 0xbabeface;
}

static void dscc4_free1(struct pci_dev *pdev)
{
	struct dscc4_pci_priv *ppriv;
	struct dscc4_dev_priv *root;
	int i;

	ppriv = pci_get_drvdata(pdev);
	root = ppriv->root;

	for (i = 0; i < dev_per_card; i++)
		unregister_hdlc_device(&root[i].hdlc);

	pci_set_drvdata(pdev, NULL);

	kfree(root);
	kfree(ppriv);
}

static int __init dscc4_init_one(struct pci_dev *pdev,
				  const struct pci_device_id *ent)
{
	struct dscc4_pci_priv *priv;
	struct dscc4_dev_priv *dpriv;
	static int cards_found = 0;
	unsigned long ioaddr;
	int i;

	printk(KERN_DEBUG "%s", version);

	if (pci_enable_device(pdev))
		goto err_out;
	if (!request_mem_region(pci_resource_start(pdev, 0),
	                	pci_resource_len(pdev, 0), "registers")) {
	        printk(KERN_ERR "%s: can't reserve MMIO region (regs)\n",
			DRV_NAME);
	        goto err_out;
	}
	if (!request_mem_region(pci_resource_start(pdev, 1),
	                        pci_resource_len(pdev, 1), "LBI interface")) {
	        printk(KERN_ERR "%s: can't reserve MMIO region (lbi)\n",
			DRV_NAME);
	        goto err_out_free_mmio_region0;
	}
	ioaddr = (unsigned long)ioremap(pci_resource_start(pdev, 0),
					pci_resource_len(pdev, 0));
	if (!ioaddr) {
		printk(KERN_ERR "%s: cannot remap MMIO region %lx @ %lx\n",
			DRV_NAME, pci_resource_len(pdev, 0),
			pci_resource_start(pdev, 0));
		goto err_out_free_mmio_region;
	}
	printk(KERN_DEBUG "Siemens DSCC4, MMIO at %#lx (regs), %#lx (lbi), IRQ %d\n",
	        pci_resource_start(pdev, 0),
	        pci_resource_start(pdev, 1), pdev->irq);

	/* Cf errata DS5 p.2 */
	pci_write_config_byte(pdev, PCI_LATENCY_TIMER, 0xf8);
	pci_set_master(pdev);

	if (dscc4_found1(pdev, ioaddr))
	        goto err_out_iounmap;

	priv = (struct dscc4_pci_priv *)pci_get_drvdata(pdev);

	if (request_irq(pdev->irq, &dscc4_irq, SA_SHIRQ, DRV_NAME, priv->root)){
		printk(KERN_WARNING "%s: IRQ %d busy\n", DRV_NAME, pdev->irq);
		goto err_out_free1;
	}

	/* power up/little endian/dma core controlled via lrda/ltda */
	writel(0x00000001, ioaddr + GMODE);
	/* Shared interrupt queue */
	{
		u32 bits;

		bits = (IRQ_RING_SIZE >> 5) - 1;
		bits |= bits << 4;
		bits |= bits << 8;
		bits |= bits << 16;
		writel(bits, ioaddr + IQLENR0);
	}
	/* Global interrupt queue */
	writel((u32)(((IRQ_RING_SIZE >> 5) - 1) << 20), ioaddr + IQLENR1);
	priv->iqcfg = (u32 *) pci_alloc_consistent(pdev,
		IRQ_RING_SIZE*sizeof(u32), &priv->iqcfg_dma);
	if (!priv->iqcfg)
		goto err_out_free_irq;
	writel(priv->iqcfg_dma, ioaddr + IQCFG);

	/*
	 * SCC 0-3 private rx/tx irq structures
	 * IQRX/TXi needs to be set soon. Learned it the hard way...
	 */
	for (i = 0; i < dev_per_card; i++) {
		dpriv = priv->root + i;
		dpriv->iqtx = (u32 *) pci_alloc_consistent(pdev,
			IRQ_RING_SIZE*sizeof(u32), &dpriv->iqtx_dma);
		if (!dpriv->iqtx)
			goto err_out_free_iqtx;
		writel(dpriv->iqtx_dma, ioaddr + IQTX0 + i*4);
	}
	for (i = 0; i < dev_per_card; i++) {
		dpriv = priv->root + i;
		dpriv->iqrx = (u32 *) pci_alloc_consistent(pdev,
			IRQ_RING_SIZE*sizeof(u32), &dpriv->iqrx_dma);
		if (!dpriv->iqrx)
			goto err_out_free_iqrx;
		writel(dpriv->iqrx_dma, ioaddr + IQRX0 + i*4);
	}

	/* Cf application hint. Beware of hard-lock condition on threshold. */
	writel(0x42104000, ioaddr + FIFOCR1);
	//writel(0x9ce69800, ioaddr + FIFOCR2);
	writel(0xdef6d800, ioaddr + FIFOCR2);
	//writel(0x11111111, ioaddr + FIFOCR4);
	writel(0x18181818, ioaddr + FIFOCR4);
	// FIXME: should depend on the chipset revision
	writel(0x0000000e, ioaddr + FIFOCR3);

	writel(0xff200001, ioaddr + GCMDR);

	cards_found++;
	return 0;

err_out_free_iqrx:
	while (--i >= 0) {
		dpriv = priv->root + i;
		pci_free_consistent(pdev, IRQ_RING_SIZE*sizeof(u32),
				    dpriv->iqrx, dpriv->iqrx_dma);
	}
	i = dev_per_card;
err_out_free_iqtx:
	while (--i >= 0) {
		dpriv = priv->root + i;
		pci_free_consistent(pdev, IRQ_RING_SIZE*sizeof(u32),
				    dpriv->iqtx, dpriv->iqtx_dma);
	}
	pci_free_consistent(pdev, IRQ_RING_SIZE*sizeof(u32), priv->iqcfg,
			    priv->iqcfg_dma);
err_out_free_irq:
	free_irq(pdev->irq, priv->root);
err_out_free1:
	dscc4_free1(pdev);
err_out_iounmap:
	iounmap ((void *)ioaddr);
err_out_free_mmio_region:
	release_mem_region(pci_resource_start(pdev, 1),
			   pci_resource_len(pdev, 1));
err_out_free_mmio_region0:
	release_mem_region(pci_resource_start(pdev, 0),
			   pci_resource_len(pdev, 0));
err_out:
	return -ENODEV;
};

/*
 * Let's hope the default values are decent enough to protect my
 * feet from the user's gun - Ueimor
 */
static void dscc4_init_registers(struct dscc4_dev_priv *dpriv,
				 struct net_device *dev)
{
	scc_writel(0x80001000, dpriv, dev, CCR0);

	scc_writel(LengthCheck | (HDLC_MAX_MRU >> 5), dpriv, dev, RLCR);

	/*
	 * No address recognition/crc-CCITT/cts enabled
	 * Shared flags transmission disabled - cf errata DS5 p.11
	 * Carrier detect disabled - cf errata p.14
	 */
	scc_writel(0x021c8000, dpriv, dev, CCR1);

	/* crc not forwarded - Cf errata DS5 p.11 */
	scc_writel(0x00050008 & ~RxActivate, dpriv, dev, CCR2);
	// crc forwarded
	//scc_writel(0x00250008 & ~RxActivate, dpriv, dev, CCR2);

	/* Don't mask RDO. Ever. */
#ifdef DSCC4_POLLING
	scc_writel(0xfffeef7f, dpriv, dev, IMR); /* Interrupt mask */
#else
	//scc_writel(0xfffaef7f, dpriv, dev, IMR); /* Interrupt mask */
	//scc_writel(0xfffaef7e, dpriv, dev, IMR); /* Interrupt mask */
	scc_writel(0xfffa8f7a, dpriv, dev, IMR); /* Interrupt mask */
#endif
}

static int dscc4_found1(struct pci_dev *pdev, unsigned long ioaddr)
{
	struct dscc4_pci_priv *ppriv;
	struct dscc4_dev_priv *root;
	int i = 0;

	root = (struct dscc4_dev_priv *)
		kmalloc(dev_per_card*sizeof(*root), GFP_KERNEL);
	if (!root) {
		printk(KERN_ERR "%s: can't allocate data\n", DRV_NAME);
		goto err_out;
	}
	memset(root, 0, dev_per_card*sizeof(*root));

	ppriv = (struct dscc4_pci_priv *) kmalloc(sizeof(*ppriv), GFP_KERNEL);
	if (!ppriv) {
		printk(KERN_ERR "%s: can't allocate private data\n", DRV_NAME);
		goto err_free_dev;
	}
	memset(ppriv, 0, sizeof(struct dscc4_pci_priv));

	for (i = 0; i < dev_per_card; i++) {
		struct dscc4_dev_priv *dpriv = root + i;
		hdlc_device *hdlc = &dpriv->hdlc;
		struct net_device *d = hdlc_to_dev(hdlc);

	        d->base_addr = ioaddr;
		d->init = NULL;
	        d->irq = pdev->irq;
	        d->open = dscc4_open;
	        d->stop = dscc4_close;
		d->set_multicast_list = NULL;
	        d->do_ioctl = dscc4_ioctl;
		d->tx_timeout = dscc4_tx_timeout;
		d->watchdog_timeo = TX_TIMEOUT;

		dpriv->dev_id = i;
		dpriv->pci_priv = ppriv;
		spin_lock_init(&dpriv->lock);

		hdlc->xmit = dscc4_start_xmit;
		hdlc->attach = dscc4_hdlc_attach;

	        if (register_hdlc_device(hdlc)) {
			printk(KERN_ERR "%s: unable to register\n", DRV_NAME);
			goto err_unregister;
	        }
		hdlc->proto = IF_PROTO_HDLC;
		SET_MODULE_OWNER(d);
		dscc4_init_registers(dpriv, d);
		dpriv->parity = PARITY_CRC16_PR0_CCITT;
		dpriv->encoding = ENCODING_NRZ;
	}
	if (dscc4_set_quartz(root, quartz) < 0)
		goto err_unregister;
	ppriv->root = root;
	spin_lock_init(&ppriv->lock);
	pci_set_drvdata(pdev, ppriv);
	return 0;

err_unregister:
	while (--i >= 0)
		unregister_hdlc_device(&root[i].hdlc);
	kfree(ppriv);
err_free_dev:
	kfree(root);
err_out:
	return -1;
};

/* FIXME: get rid of the unneeded code */
static void dscc4_timer(unsigned long data)
{
	struct net_device *dev = (struct net_device *)data;
	struct dscc4_dev_priv *dpriv = dscc4_priv(dev);
//	struct dscc4_pci_priv *ppriv;

	goto done;
done:
        dpriv->timer.expires = jiffies + TX_TIMEOUT;
        add_timer(&dpriv->timer);
}

static void dscc4_tx_timeout(struct net_device *dev)
{
	/* FIXME: something is missing there */
}

static int dscc4_loopback_check(struct dscc4_dev_priv *dpriv)
{
	sync_serial_settings *settings = &dpriv->settings;

	if (settings->loopback && (settings->clock_type != CLOCK_INT)) {
		struct net_device *dev = hdlc_to_dev(&dpriv->hdlc);

		printk(KERN_INFO "%s: loopback requires clock\n", dev->name);
		return -1;
	}
	return 0;
}

static int dscc4_open(struct net_device *dev)
{
	struct dscc4_dev_priv *dpriv = dscc4_priv(dev);
	hdlc_device *hdlc = &dpriv->hdlc;
	struct dscc4_pci_priv *ppriv;
	int ret = -EAGAIN;

	if ((dscc4_loopback_check(dpriv) < 0) || !dev->hard_start_xmit)