sa1100_ir.c

内核linux2.4.20,可跟rtlinux3.2打补丁 组成实时linux系统,编译内核

	if (stat & HSSR1_EOF) {
		si->rxskb = NULL;

		skb_put(skb, len);
		skb->dev = dev;
		skb->mac.raw = skb->data;
		skb->protocol = htons(ETH_P_IRDA);
		si->stats.rx_packets++;
		si->stats.rx_bytes += len;

		/*
		 * Before we pass the buffer up, allocate a new one.
		 */
		sa1100_irda_rx_alloc(si);

		netif_rx(skb);
	} else {
		/*
		 * Remap the buffer.
		 */
		si->rxbuf_dma = pci_map_single(NULL, si->rxskb->data,
						HPSIR_MAX_RXLEN,
						PCI_DMA_FROMDEVICE);
	}
}

/*
 * FIR format interrupt service routine.  We only have to
 * handle RX events; transmit events go via the TX DMA handler.
 *
 * No matter what, we disable RX, process, and the restart RX.
 */
static void sa1100_irda_fir_irq(struct net_device *dev)
{
	struct sa1100_irda *si = dev->priv;

	/*
	 * Stop RX DMA
	 */
	sa1100_dma_stop(si->rxdma);

	/*
	 * Framing error - we throw away the packet completely.
	 * Clearing RXE flushes the error conditions and data
	 * from the fifo.
	 */
	if (Ser2HSSR0 & (HSSR0_FRE | HSSR0_RAB)) {
		si->stats.rx_errors++;

		if (Ser2HSSR0 & HSSR0_FRE)
			si->stats.rx_frame_errors++;

		/*
		 * Clear out the DMA...
		 */
		Ser2HSCR0 = si->hscr0 | HSCR0_HSSP;

		/*
		 * Clear selected status bits now, so we
		 * don't miss them next time around.
		 */
		Ser2HSSR0 = HSSR0_FRE | HSSR0_RAB;
	}

	/*
	 * Deal with any receive errors.  The any of the lowest
	 * 8 bytes in the FIFO may contain an error.  We must read
	 * them one by one.  The "error" could even be the end of
	 * packet!
	 */
	if (Ser2HSSR0 & HSSR0_EIF)
		sa1100_irda_fir_error(si, dev);

	/*
	 * No matter what happens, we must restart reception.
	 */
	sa1100_irda_rx_dma_start(si);
}

static void sa1100_irda_irq(int irq, void *dev_id, struct pt_regs *regs)
{
	struct net_device *dev = dev_id;
	if (IS_FIR(((struct sa1100_irda *)dev->priv)))
		sa1100_irda_fir_irq(dev);
	else
		sa1100_irda_hpsir_irq(dev);
}

/*
 * TX DMA completion handler.
 */
static void sa1100_irda_txdma_irq(void *id, int len)
{
	struct net_device *dev = id;
	struct sa1100_irda *si = dev->priv;
	struct sk_buff *skb = si->txskb;

	si->txskb = NULL;

	/*
	 * Wait for the transmission to complete.  Unfortunately,
	 * the hardware doesn't give us an interrupt to indicate
	 * "end of frame".
	 */
	do
		rmb();
	while (!(Ser2HSSR0 & HSSR0_TUR) || Ser2HSSR1 & HSSR1_TBY);

	/*
	 * Clear the transmit underrun bit.
	 */
	Ser2HSSR0 = HSSR0_TUR;

	/*
	 * Do we need to change speed?  Note that we're lazy
	 * here - we don't free the old rxskb.  We don't need
	 * to allocate a buffer either.
	 */
	if (si->newspeed) {
		sa1100_irda_set_speed(si, si->newspeed);
		si->newspeed = 0;
	}

	/*
	 * Start reception.  This disables the transmitter for
	 * us.  This will be using the existing RX buffer.
	 */
	sa1100_irda_rx_dma_start(si);

	/*
	 * Account and free the packet.
	 */
	if (skb) {
		pci_unmap_single(NULL, si->txbuf_dma, len, PCI_DMA_TODEVICE);
		si->stats.tx_packets ++;
		si->stats.tx_bytes += len;
		dev_kfree_skb_irq(skb);
	}

	/*
	 * Make sure that the TX queue is available for sending
	 * (for retries).  TX has priority over RX at all times.
	 */
	netif_wake_queue(dev);
}

/*
 * Note that we will never build up a backlog of frames; the protocol is a
 * half duplex protocol which basically means we transmit a frame, we
 * receive a frame, we transmit the next frame etc.
 */
static int sa1100_irda_hard_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct sa1100_irda *si = dev->priv;
	int speed = irda_get_next_speed(skb);

	/*
	 * Does this packet contain a request to change the interface
	 * speed?  If so, remember it until we complete the transmission
	 * of this frame.
	 */
	if (speed != si->speed && speed != -1)
		si->newspeed = speed;

	/*
	 * If this is an empty frame, we can bypass a lot.
	 */
	if (skb->len == 0) {
		if (si->newspeed) {
			si->newspeed = 0;
			sa1100_irda_set_speed(si, speed);
		}
		dev_kfree_skb(skb);
		return 0;
	}

	if (!IS_FIR(si)) {
		si->tx_buff.data = si->tx_buff.head;
		si->tx_buff.len  = async_wrap_skb(skb, si->tx_buff.data,
						  si->tx_buff.truesize);

		/*
		 * Set the transmit interrupt enable.  This will fire
		 * off an interrupt immediately.  Note that we disable
		 * the receiver so we won't get spurious characteres
		 * received.
		 */
		Ser2UTCR3 = UTCR3_TIE | UTCR3_TXE;

		dev_kfree_skb(skb);
	} else {
		int mtt = irda_get_mtt(skb);

		/*
		 * We must not be transmitting...
		 */
		if (si->txskb)
			BUG();

		netif_stop_queue(dev);

		si->txskb = skb;
		si->txbuf_dma = pci_map_single(NULL, skb->data,
					 skb->len, PCI_DMA_TODEVICE);

		sa1100_dma_queue_buffer(si->txdma, dev, si->txbuf_dma,
					skb->len);

		/*
		 * If we have a mean turn-around time, impose the specified
		 * specified delay.  We could shorten this by timing from
		 * the point we received the packet.
		 */
		if (mtt)
			udelay(mtt);

		Ser2HSCR0 = si->hscr0 | HSCR0_HSSP | HSCR0_TXE;
	}

	dev->trans_start = jiffies;

	return 0;
}

static int
sa1100_irda_ioctl(struct net_device *dev, struct ifreq *ifreq, int cmd)
{
	struct if_irda_req *rq = (struct if_irda_req *)ifreq;
	struct sa1100_irda *si = dev->priv;
	int ret = -EOPNOTSUPP;

	switch (cmd) {
	case SIOCSBANDWIDTH:
		if (capable(CAP_NET_ADMIN)) {
			/*
			 * We are unable to set the speed if the
			 * device is not running.
			 */
			if (si->open) {
				ret = sa1100_irda_set_speed(si,
						rq->ifr_baudrate);
			} else {
				printk("sa1100_irda_ioctl: SIOCSBANDWIDTH: !netif_running\n");
				ret = 0;
			}
		}
		break;

	case SIOCSMEDIABUSY:
		ret = -EPERM;
		if (capable(CAP_NET_ADMIN)) {
			irda_device_set_media_busy(dev, TRUE);
			ret = 0;
		}
		break;

	case SIOCGRECEIVING:
		rq->ifr_receiving = IS_FIR(si) ? 0
					: si->rx_buff.state != OUTSIDE_FRAME;
		break;

	default:
		break;
	}
		
	return ret;
}

static struct net_device_stats *sa1100_irda_stats(struct net_device *dev)
{
	struct sa1100_irda *si = dev->priv;
	return &si->stats;
}

static int sa1100_irda_start(struct net_device *dev)
{
	struct sa1100_irda *si = dev->priv;
	int err;

	MOD_INC_USE_COUNT;

	si->speed = 9600;

	err = request_irq(dev->irq, sa1100_irda_irq, 0, dev->name, dev);
	if (err)
		goto err_irq;

	err = sa1100_request_dma(&si->rxdma, "IrDA receive", DMA_Ser2HSSPRd);
	if (err)
		goto err_rx_dma;

	err = sa1100_request_dma(&si->txdma, "IrDA transmit", DMA_Ser2HSSPWr);
	if (err)
		goto err_tx_dma;

	/*
	 * The interrupt must remain disabled for now.
	 */
	disable_irq(dev->irq);

	/*
	 * Setup the serial port for the specified speed.
	 */
	err = sa1100_irda_startup(si);
	if (err)
		goto err_startup;

	/*
	 * Open a new IrLAP layer instance.
	 */
	si->irlap = irlap_open(dev, &si->qos, "sa1100");
	err = -ENOMEM;
	if (!si->irlap)
		goto err_irlap;

	sa1100_dma_set_callback(si->txdma, sa1100_irda_txdma_irq);

	/*
	 * Now enable the interrupt and start the queue
	 */
	si->open = 1;
	sa1100_set_power(si, power_level); /* low power mode */
	enable_irq(dev->irq);
	netif_start_queue(dev);
	return 0;

err_irlap:
	si->open = 0;
	sa1100_irda_shutdown(si);
err_startup:
	sa1100_free_dma(si->txdma);
err_tx_dma:
	sa1100_free_dma(si->rxdma);
err_rx_dma:
	free_irq(dev->irq, dev);
err_irq:
	MOD_DEC_USE_COUNT;
	return err;
}

static int sa1100_irda_stop(struct net_device *dev)
{
	struct sa1100_irda *si = dev->priv;

	disable_irq(dev->irq);
	sa1100_irda_shutdown(si);

	/*
	 * If we have been doing DMA receive, make sure we
	 * tidy that up cleanly.
	 */
	if (si->rxskb) {
		pci_unmap_single(NULL, si->rxbuf_dma, HPSIR_MAX_RXLEN,
				 PCI_DMA_FROMDEVICE);
		dev_kfree_skb(si->rxskb);
		si->rxskb = NULL;
	}

	/* Stop IrLAP */
	if (si->irlap) {
		irlap_close(si->irlap);
		si->irlap = NULL;
	}

	netif_stop_queue(dev);
	si->open = 0;

	/*
	 * Free resources
	 */
	sa1100_free_dma(si->txdma);
	sa1100_free_dma(si->rxdma);
	free_irq(dev->irq, dev);

	sa1100_set_power(si, 0);

	MOD_DEC_USE_COUNT;

	return 0;
}

static int sa1100_irda_init_iobuf(iobuff_t *io, int size)
{
	io->head = kmalloc(size, GFP_KERNEL | GFP_DMA);
	if (io->head != NULL) {
		io->truesize = size;
		io->in_frame = FALSE;
		io->state    = OUTSIDE_FRAME;
		io->data     = io->head;
	}
	return io->head ? 0 : -ENOMEM;
}

static int sa1100_irda_net_init(struct net_device *dev)
{
	struct sa1100_irda *si = dev->priv;
	unsigned int baudrate_mask;
	int err = -ENOMEM;

	si = kmalloc(sizeof(struct sa1100_irda), GFP_KERNEL);
	if (!si)
		goto out;

	memset(si, 0, sizeof(*si));

	/*
	 * Initialise the HP-SIR buffers
	 */
	err = sa1100_irda_init_iobuf(&si->rx_buff, 14384);
	if (err)
		goto out;
	err = sa1100_irda_init_iobuf(&si->tx_buff, 4000);
	if (err)
		goto out_free_rx;

	dev->priv = si;
	dev->hard_start_xmit	= sa1100_irda_hard_xmit;
	dev->open		= sa1100_irda_start;
	dev->stop		= sa1100_irda_stop;
	dev->do_ioctl		= sa1100_irda_ioctl;
	dev->get_stats		= sa1100_irda_stats;

	irda_device_setup(dev);
	irda_init_max_qos_capabilies(&si->qos);

	/*
	 * We support original IRDA up to 115k2. (we don't currently
	 * support 4Mbps).  Min Turn Time set to 1ms or greater.
	 */
	baudrate_mask = IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;
	baudrate_mask |= IR_4000000 << 8;
	si->qos.baud_rate.bits &= baudrate_mask;
	si->qos.min_turn_time.bits = 7;

	irda_qos_bits_to_value(&si->qos);

	si->utcr4 = UTCR4_HPSIR;
	if (tx_lpm)
		si->utcr4 |= UTCR4_Z1_6us;

	/*
	 * Initially enable HP-SIR modulation, and ensure that the port
	 * is disabled.
	 */
	Ser2UTCR3 = 0;
	Ser2UTCR4 = si->utcr4;
	Ser2HSCR0 = HSCR0_UART;

#ifdef CONFIG_PM
	/*
	 * Power-Management is optional.
	 */
	si->pmdev = pm_register(PM_SYS_DEV, PM_SYS_IRDA, sa1100_irda_pmproc);
	if (si->pmdev)
		si->pmdev->data = dev;
#endif

	return 0;

	kfree(si->tx_buff.head);
out_free_rx:
	kfree(si->rx_buff.head);
out:
	kfree(si);

	return err;
}

/*
 * Remove all traces of this driver module from the kernel, so we can't be
 * called.  Note that the device has already been stopped, so we don't have
 * to worry about interrupts or dma.
 */
static void sa1100_irda_net_uninit(struct net_device *dev)
{
	struct sa1100_irda *si = dev->priv;

	dev->hard_start_xmit	= NULL;
	dev->open		= NULL;
	dev->stop		= NULL;
	dev->do_ioctl		= NULL;
	dev->get_stats		= NULL;
	dev->priv		= NULL;

	pm_unregister(si->pmdev);

	kfree(si->tx_buff.head);
	kfree(si->rx_buff.head);
	kfree(si);
}

#ifdef MODULE
static
#endif
int __init sa1100_irda_init(void)
{
	struct net_device *dev;
	int err;

	/*
	 * Limit power level a sensible range.
	 */
	if (power_level < 1)
		power_level = 1;
	if (power_level > 3)
		power_level = 3;

	err = request_mem_region(__PREG(Ser2UTCR0), 0x24, "IrDA") ? 0 : -EBUSY;
	if (err)
		goto err_mem_1;
	err = request_mem_region(__PREG(Ser2HSCR0), 0x1c, "IrDA") ? 0 : -EBUSY;
	if (err)
		goto err_mem_2;
	err = request_mem_region(__PREG(Ser2HSCR2), 0x04, "IrDA") ? 0 : -EBUSY;
	if (err)
		goto err_mem_3;

	rtnl_lock();
	dev = dev_alloc("irda%d", &err);
	if (dev) {
		dev->irq    = IRQ_Ser2ICP;
		dev->init   = sa1100_irda_net_init;
		dev->uninit = sa1100_irda_net_uninit;

		err = register_netdevice(dev);

		if (err)
			kfree(dev);
		else
			netdev = dev;
	}
	rtnl_unlock();

	if (err) {
		release_mem_region(__PREG(Ser2HSCR2), 0x04);
err_mem_3:
		release_mem_region(__PREG(Ser2HSCR0), 0x1c);
err_mem_2:
		release_mem_region(__PREG(Ser2UTCR0), 0x24);
	}
err_mem_1:
	return err;
}

static void __exit sa1100_irda_exit(void)
{
	struct net_device *dev = netdev;

	netdev = NULL;
	if (dev) {
		rtnl_lock();
		unregister_netdevice(dev);
		rtnl_unlock();
	}

	release_mem_region(__PREG(Ser2HSCR2), 0x04);
	release_mem_region(__PREG(Ser2HSCR0), 0x1c);
	release_mem_region(__PREG(Ser2UTCR0), 0x24);

	/*
	 * We now know that the netdevice is no longer in use, and all
	 * references to our driver have been removed.  The only structure
	 * which may still be present is the netdevice, which will get
	 * cleaned up by net/core/dev.c
	 */
}

#ifdef MODULE
module_init(sa1100_irda_init);
module_exit(sa1100_irda_exit);
#endif

MODULE_AUTHOR("Russell King <[e-mail]>");
MODULE_DESCRIPTION("StrongARM SA1100 IrDA driver");
MODULE_LICENSE("GPL");
MODULE_PARM(power_level, "i");
MODULE_PARM_DESC(power_level, "IrDA power level, 1 (low) to 3 (high)");
MODULE_PARM(tx_lpm, "i");
MODULE_PARM_DESC(tx_lpm, "Enable transmitter low power (1.6us) mode");
EXPORT_NO_SYMBOLS;