vlsi_ir.c

《linux驱动程序设计从入门到精通》一书中所有的程序代码含驱动和相应的应用程序

	return 0;
}

static int vlsi_create_hwif(vlsi_irda_dev_t *idev)
{
	char 			*ringarea;
	struct ring_descr_hw	*hwmap;

	idev->virtaddr = NULL;
	idev->busaddr = 0;

	ringarea = pci_alloc_consistent(idev->pdev, HW_RING_AREA_SIZE, &idev->busaddr);
	if (!ringarea) {
		IRDA_ERROR("%s: insufficient memory for descriptor rings\n",
			   __FUNCTION__);
		goto out;
	}
	memset(ringarea, 0, HW_RING_AREA_SIZE);

	hwmap = (struct ring_descr_hw *)ringarea;
	idev->rx_ring = vlsi_alloc_ring(idev->pdev, hwmap, ringsize[1],
					XFER_BUF_SIZE, PCI_DMA_FROMDEVICE);
	if (idev->rx_ring == NULL)
		goto out_unmap;

	hwmap += MAX_RING_DESCR;
	idev->tx_ring = vlsi_alloc_ring(idev->pdev, hwmap, ringsize[0],
					XFER_BUF_SIZE, PCI_DMA_TODEVICE);
	if (idev->tx_ring == NULL)
		goto out_free_rx;

	idev->virtaddr = ringarea;
	return 0;

out_free_rx:
	vlsi_free_ring(idev->rx_ring);
out_unmap:
	idev->rx_ring = idev->tx_ring = NULL;
	pci_free_consistent(idev->pdev, HW_RING_AREA_SIZE, ringarea, idev->busaddr);
	idev->busaddr = 0;
out:
	return -ENOMEM;
}

static int vlsi_destroy_hwif(vlsi_irda_dev_t *idev)
{
	vlsi_free_ring(idev->rx_ring);
	vlsi_free_ring(idev->tx_ring);
	idev->rx_ring = idev->tx_ring = NULL;

	if (idev->busaddr)
		pci_free_consistent(idev->pdev,HW_RING_AREA_SIZE,idev->virtaddr,idev->busaddr);

	idev->virtaddr = NULL;
	idev->busaddr = 0;

	return 0;
}

/********************************************************/

static int vlsi_process_rx(struct vlsi_ring *r, struct ring_descr *rd)
{
	u16		status;
	int		crclen, len = 0;
	struct sk_buff	*skb;
	int		ret = 0;
	struct net_device *ndev = (struct net_device *)pci_get_drvdata(r->pdev);
	vlsi_irda_dev_t *idev = ndev->priv;

	pci_dma_sync_single_for_cpu(r->pdev, rd_get_addr(rd), r->len, r->dir);
	/* dma buffer now owned by the CPU */
	status = rd_get_status(rd);
	if (status & RD_RX_ERROR) {
		if (status & RD_RX_OVER)  
			ret |= VLSI_RX_OVER;
		if (status & RD_RX_LENGTH)  
			ret |= VLSI_RX_LENGTH;
		if (status & RD_RX_PHYERR)  
			ret |= VLSI_RX_FRAME;
		if (status & RD_RX_CRCERR)  
			ret |= VLSI_RX_CRC;
		goto done;
	}

	len = rd_get_count(rd);
	crclen = (idev->mode==IFF_FIR) ? sizeof(u32) : sizeof(u16);
	len -= crclen;		/* remove trailing CRC */
	if (len <= 0) {
		IRDA_DEBUG(0, "%s: strange frame (len=%d)\n", __FUNCTION__, len);
		ret |= VLSI_RX_DROP;
		goto done;
	}

	if (idev->mode == IFF_SIR) {	/* hw checks CRC in MIR, FIR mode */

		/* rd->buf is a streaming PCI_DMA_FROMDEVICE map. Doing the
		 * endian-adjustment there just in place will dirty a cache line
		 * which belongs to the map and thus we must be sure it will
		 * get flushed before giving the buffer back to hardware.
		 * vlsi_fill_rx() will do this anyway - but here we rely on.
		 */
		le16_to_cpus(rd->buf+len);
		if (irda_calc_crc16(INIT_FCS,rd->buf,len+crclen) != GOOD_FCS) {
			IRDA_DEBUG(0, "%s: crc error\n", __FUNCTION__);
			ret |= VLSI_RX_CRC;
			goto done;
		}
	}

	if (!rd->skb) {
		IRDA_WARNING("%s: rx packet lost\n", __FUNCTION__);
		ret |= VLSI_RX_DROP;
		goto done;
	}

	skb = rd->skb;
	rd->skb = NULL;
	skb->dev = ndev;
	memcpy(skb_put(skb,len), rd->buf, len);
	skb->mac.raw = skb->data;
	if (in_interrupt())
		netif_rx(skb);
	else
		netif_rx_ni(skb);
	ndev->last_rx = jiffies;

done:
	rd_set_status(rd, 0);
	rd_set_count(rd, 0);
	/* buffer still owned by CPU */

	return (ret) ? -ret : len;
}

static void vlsi_fill_rx(struct vlsi_ring *r)
{
	struct ring_descr *rd;

	for (rd = ring_last(r); rd != NULL; rd = ring_put(r)) {
		if (rd_is_active(rd)) {
			IRDA_WARNING("%s: driver bug: rx descr race with hw\n",
				     __FUNCTION__);
			vlsi_ring_debug(r);
			break;
		}
		if (!rd->skb) {
			rd->skb = dev_alloc_skb(IRLAP_SKB_ALLOCSIZE);
			if (rd->skb) {
				skb_reserve(rd->skb,1);
				rd->skb->protocol = htons(ETH_P_IRDA);
			}
			else
				break;	/* probably not worth logging? */
		}
		/* give dma buffer back to busmaster */
		pci_dma_sync_single_for_device(r->pdev, rd_get_addr(rd), r->len, r->dir);
		rd_activate(rd);
	}
}

static void vlsi_rx_interrupt(struct net_device *ndev)
{
	vlsi_irda_dev_t *idev = ndev->priv;
	struct vlsi_ring *r = idev->rx_ring;
	struct ring_descr *rd;
	int ret;

	for (rd = ring_first(r); rd != NULL; rd = ring_get(r)) {

		if (rd_is_active(rd))
			break;

		ret = vlsi_process_rx(r, rd);

		if (ret < 0) {
			ret = -ret;
			idev->stats.rx_errors++;
			if (ret & VLSI_RX_DROP)  
				idev->stats.rx_dropped++;
			if (ret & VLSI_RX_OVER)  
				idev->stats.rx_over_errors++;
			if (ret & VLSI_RX_LENGTH)  
				idev->stats.rx_length_errors++;
			if (ret & VLSI_RX_FRAME)  
				idev->stats.rx_frame_errors++;
			if (ret & VLSI_RX_CRC)  
				idev->stats.rx_crc_errors++;
		}
		else if (ret > 0) {
			idev->stats.rx_packets++;
			idev->stats.rx_bytes += ret;
		}
	}

	do_gettimeofday(&idev->last_rx); /* remember "now" for later mtt delay */

	vlsi_fill_rx(r);

	if (ring_first(r) == NULL) {
		/* we are in big trouble, if this should ever happen */
		IRDA_ERROR("%s: rx ring exhausted!\n", __FUNCTION__);
		vlsi_ring_debug(r);
	}
	else
		outw(0, ndev->base_addr+VLSI_PIO_PROMPT);
}

/* caller must have stopped the controller from busmastering */

static void vlsi_unarm_rx(vlsi_irda_dev_t *idev)
{
	struct vlsi_ring *r = idev->rx_ring;
	struct ring_descr *rd;
	int ret;

	for (rd = ring_first(r); rd != NULL; rd = ring_get(r)) {

		ret = 0;
		if (rd_is_active(rd)) {
			rd_set_status(rd, 0);
			if (rd_get_count(rd)) {
				IRDA_DEBUG(0, "%s - dropping rx packet\n", __FUNCTION__);
				ret = -VLSI_RX_DROP;
			}
			rd_set_count(rd, 0);
			pci_dma_sync_single_for_cpu(r->pdev, rd_get_addr(rd), r->len, r->dir);
			if (rd->skb) {
				dev_kfree_skb_any(rd->skb);
				rd->skb = NULL;
			}
		}
		else
			ret = vlsi_process_rx(r, rd);

		if (ret < 0) {
			ret = -ret;
			idev->stats.rx_errors++;
			if (ret & VLSI_RX_DROP)  
				idev->stats.rx_dropped++;
			if (ret & VLSI_RX_OVER)  
				idev->stats.rx_over_errors++;
			if (ret & VLSI_RX_LENGTH)  
				idev->stats.rx_length_errors++;
			if (ret & VLSI_RX_FRAME)  
				idev->stats.rx_frame_errors++;
			if (ret & VLSI_RX_CRC)  
				idev->stats.rx_crc_errors++;
		}
		else if (ret > 0) {
			idev->stats.rx_packets++;
			idev->stats.rx_bytes += ret;
		}
	}
}

/********************************************************/

static int vlsi_process_tx(struct vlsi_ring *r, struct ring_descr *rd)
{
	u16		status;
	int		len;
	int		ret;

	pci_dma_sync_single_for_cpu(r->pdev, rd_get_addr(rd), r->len, r->dir);
	/* dma buffer now owned by the CPU */
	status = rd_get_status(rd);
	if (status & RD_TX_UNDRN)
		ret = VLSI_TX_FIFO;
	else
		ret = 0;
	rd_set_status(rd, 0);

	if (rd->skb) {
		len = rd->skb->len;
		dev_kfree_skb_any(rd->skb);
		rd->skb = NULL;
	}
	else	/* tx-skb already freed? - should never happen */
		len = rd_get_count(rd);		/* incorrect for SIR! (due to wrapping) */

	rd_set_count(rd, 0);
	/* dma buffer still owned by the CPU */

	return (ret) ? -ret : len;
}

static int vlsi_set_baud(vlsi_irda_dev_t *idev, unsigned iobase)
{
	u16 nphyctl;
	u16 config;
	unsigned mode;
	int	ret;
	int	baudrate;
	int	fifocnt;

	baudrate = idev->new_baud;
	IRDA_DEBUG(2, "%s: %d -> %d\n", __FUNCTION__, idev->baud, idev->new_baud);
	if (baudrate == 4000000) {
		mode = IFF_FIR;
		config = IRCFG_FIR;
		nphyctl = PHYCTL_FIR;
	}
	else if (baudrate == 1152000) {
		mode = IFF_MIR;
		config = IRCFG_MIR | IRCFG_CRC16;
		nphyctl = PHYCTL_MIR(clksrc==3);
	}
	else {
		mode = IFF_SIR;
		config = IRCFG_SIR | IRCFG_SIRFILT  | IRCFG_RXANY;
		switch(baudrate) {
			default:
				IRDA_WARNING("%s: undefined baudrate %d - fallback to 9600!\n",
					     __FUNCTION__, baudrate);
				baudrate = 9600;
				/* fallthru */
			case 2400:
			case 9600:
			case 19200:
			case 38400:
			case 57600:
			case 115200:
				nphyctl = PHYCTL_SIR(baudrate,sirpulse,clksrc==3);
				break;
		}
	}
	config |= IRCFG_MSTR | IRCFG_ENRX;

	fifocnt = inw(iobase+VLSI_PIO_RCVBCNT) & RCVBCNT_MASK;
	if (fifocnt != 0) {
		IRDA_DEBUG(0, "%s: rx fifo not empty(%d)\n", __FUNCTION__, fifocnt);
	}

	outw(0, iobase+VLSI_PIO_IRENABLE);
	outw(config, iobase+VLSI_PIO_IRCFG);
	outw(nphyctl, iobase+VLSI_PIO_NPHYCTL);
	wmb();
	outw(IRENABLE_PHYANDCLOCK, iobase+VLSI_PIO_IRENABLE);
	mb();

	udelay(1);	/* chip applies IRCFG on next rising edge of its 8MHz clock */

	/* read back settings for validation */

	config = inw(iobase+VLSI_PIO_IRENABLE) & IRENABLE_MASK;

	if (mode == IFF_FIR)
		config ^= IRENABLE_FIR_ON;
	else if (mode == IFF_MIR)
		config ^= (IRENABLE_MIR_ON|IRENABLE_CRC16_ON);
	else
		config ^= IRENABLE_SIR_ON;

	if (config != (IRENABLE_PHYANDCLOCK|IRENABLE_ENRXST)) {
		IRDA_WARNING("%s: failed to set %s mode!\n", __FUNCTION__,
			(mode==IFF_SIR)?"SIR":((mode==IFF_MIR)?"MIR":"FIR"));
		ret = -1;
	}
	else {
		if (inw(iobase+VLSI_PIO_PHYCTL) != nphyctl) {
			IRDA_WARNING("%s: failed to apply baudrate %d\n",
				     __FUNCTION__, baudrate);
			ret = -1;
		}
		else {
			idev->mode = mode;
			idev->baud = baudrate;
			idev->new_baud = 0;
			ret = 0;
		}
	}

	if (ret)
		vlsi_reg_debug(iobase,__FUNCTION__);

	return ret;
}

static int vlsi_hard_start_xmit(struct sk_buff *skb, struct net_device *ndev)
{
	vlsi_irda_dev_t *idev = ndev->priv;
	struct vlsi_ring	*r = idev->tx_ring;
	struct ring_descr *rd;
	unsigned long flags;
	unsigned iobase = ndev->base_addr;
	u8 status;
	u16 config;
	int mtt;
	int len, speed;
	struct timeval  now, ready;
	char *msg = NULL;

	speed = irda_get_next_speed(skb);
	spin_lock_irqsave(&idev->lock, flags);
	if (speed != -1  &&  speed != idev->baud) {
		netif_stop_queue(ndev);
		idev->new_baud = speed;
		status = RD_TX_CLRENTX;  /* stop tx-ring after this frame */
	}
	else
		status = 0;

	if (skb->len == 0) {
		/* handle zero packets - should be speed change */
		if (status == 0) {
			msg = "bogus zero-length packet";
			goto drop_unlock;
		}

		/* due to the completely asynch tx operation we might have
		 * IrLAP racing with the hardware here, f.e. if the controller
		 * is just sending the last packet with current speed while
		 * the LAP is already switching the speed using synchronous
		 * len=0 packet. Immediate execution would lead to hw lockup
		 * requiring a powercycle to reset. Good candidate to trigger
		 * this is the final UA:RSP packet after receiving a DISC:CMD
		 * when getting the LAP down.
		 * Note that we are not protected by the queue_stop approach
		 * because the final UA:RSP arrives _without_ request to apply
		 * new-speed-after-this-packet - hence the driver doesn't know
		 * this was the last packet and doesn't stop the queue. So the
		 * forced switch to default speed from LAP gets through as fast
		 * as only some 10 usec later while the UA:RSP is still processed
		 * by the hardware and we would get screwed.
		 */

		if (ring_first(idev->tx_ring) == NULL) {
			/* no race - tx-ring already empty */
			vlsi_set_baud(idev, iobase);
			netif_wake_queue(ndev);
		}
		else
			;
			/* keep the speed change pending like it would
			 * for any len>0 packet. tx completion interrupt
			 * will apply it when the tx ring becomes empty.
			 */
		spin_unlock_irqrestore(&idev->lock, flags);
		dev_kfree_skb_any(skb);
		return 0;
	}

	/* sanity checks - simply drop the packet */

	rd = ring_last(r);
	if (!rd) {
		msg = "ring full, but queue wasn't stopped";
		goto drop_unlock;
	}

	if (rd_is_active(rd)) {
		msg = "entry still owned by hw";
		goto drop_unlock;
	}

	if (!rd->buf) {
		msg = "tx ring entry without pci buffer";
		goto drop_unlock;
	}

	if (rd->skb) {
		msg = "ring entry with old skb still attached";
		goto drop_unlock;
	}

	/* no need for serialization or interrupt disable during mtt */
	spin_unlock_irqrestore(&idev->lock, flags);

	if ((mtt = irda_get_mtt(skb)) > 0) {
	
		ready.tv_usec = idev->last_rx.tv_usec + mtt;
		ready.tv_sec = idev->last_rx.tv_sec;
		if (ready.tv_usec >= 1000000) {
			ready.tv_usec -= 1000000;
			ready.tv_sec++;		/* IrLAP 1.1: mtt always < 1 sec */
		}