smsc-ircc2.c

底层驱动开发

	/* Setup DMA controller (must be done after enabling chip DMA) */
	irda_setup_dma(self->io.dma, self->tx_buff_dma, self->tx_buff.len,
		       DMA_TX_MODE);

	/* Enable interrupt */

	register_bank(iobase, 0);
	outb(IRCC_IER_ACTIVE_FRAME | IRCC_IER_EOM, iobase + IRCC_IER);
	outb(IRCC_MASTER_INT_EN, iobase + IRCC_MASTER);

	/* Enable transmit */
	outb(IRCC_LCR_B_SCE_TRANSMIT | IRCC_LCR_B_SIP_ENABLE, iobase + IRCC_LCR_B);
}

/*
 * Function smsc_ircc_dma_xmit_complete (self)
 *
 *    The transfer of a frame in finished. This function will only be called
 *    by the interrupt handler
 *
 */
static void smsc_ircc_dma_xmit_complete(struct smsc_ircc_cb *self)
{
	int iobase = self->io.fir_base;

	IRDA_DEBUG(3, "%s\n", __FUNCTION__);
#if 0
	/* Disable Tx */
	register_bank(iobase, 0);
	outb(0x00, iobase + IRCC_LCR_B);
#endif
	register_bank(iobase, 1);
	outb(inb(iobase + IRCC_SCE_CFGB) & ~IRCC_CFGB_DMA_ENABLE,
	     iobase + IRCC_SCE_CFGB);

	/* Check for underrun! */
	register_bank(iobase, 0);
	if (inb(iobase + IRCC_LSR) & IRCC_LSR_UNDERRUN) {
		self->stats.tx_errors++;
		self->stats.tx_fifo_errors++;

		/* Reset error condition */
		register_bank(iobase, 0);
		outb(IRCC_MASTER_ERROR_RESET, iobase + IRCC_MASTER);
		outb(0x00, iobase + IRCC_MASTER);
	} else {
		self->stats.tx_packets++;
		self->stats.tx_bytes += self->tx_buff.len;
	}

	/* Check if it's time to change the speed */
	if (self->new_speed) {
		smsc_ircc_change_speed(self, self->new_speed);
		self->new_speed = 0;
	}

	netif_wake_queue(self->netdev);
}

/*
 * Function smsc_ircc_dma_receive(self)
 *
 *    Get ready for receiving a frame. The device will initiate a DMA
 *    if it starts to receive a frame.
 *
 */
static int smsc_ircc_dma_receive(struct smsc_ircc_cb *self)
{
	int iobase = self->io.fir_base;
#if 0
	/* Turn off chip DMA */
	register_bank(iobase, 1);
	outb(inb(iobase + IRCC_SCE_CFGB) & ~IRCC_CFGB_DMA_ENABLE,
	     iobase + IRCC_SCE_CFGB);
#endif

	/* Disable Tx */
	register_bank(iobase, 0);
	outb(0x00, iobase + IRCC_LCR_B);

	/* Turn off chip DMA */
	register_bank(iobase, 1);
	outb(inb(iobase + IRCC_SCE_CFGB) & ~IRCC_CFGB_DMA_ENABLE,
	     iobase + IRCC_SCE_CFGB);

	self->io.direction = IO_RECV;
	self->rx_buff.data = self->rx_buff.head;

	/* Set max Rx frame size */
	register_bank(iobase, 4);
	outb((2050 >> 8) & 0x0f, iobase + IRCC_RX_SIZE_HI);
	outb(2050 & 0xff, iobase + IRCC_RX_SIZE_LO);

	/* Setup DMA controller */
	irda_setup_dma(self->io.dma, self->rx_buff_dma, self->rx_buff.truesize,
		       DMA_RX_MODE);

	/* Enable burst mode chip Rx DMA */
	register_bank(iobase, 1);
	outb(inb(iobase + IRCC_SCE_CFGB) | IRCC_CFGB_DMA_ENABLE |
	     IRCC_CFGB_DMA_BURST, iobase + IRCC_SCE_CFGB);

	/* Enable interrupt */
	register_bank(iobase, 0);
	outb(IRCC_IER_ACTIVE_FRAME | IRCC_IER_EOM, iobase + IRCC_IER);
	outb(IRCC_MASTER_INT_EN, iobase + IRCC_MASTER);

	/* Enable receiver */
	register_bank(iobase, 0);
	outb(IRCC_LCR_B_SCE_RECEIVE | IRCC_LCR_B_SIP_ENABLE,
	     iobase + IRCC_LCR_B);

	return 0;
}

/*
 * Function smsc_ircc_dma_receive_complete(self)
 *
 *    Finished with receiving frames
 *
 */
static void smsc_ircc_dma_receive_complete(struct smsc_ircc_cb *self)
{
	struct sk_buff *skb;
	int len, msgcnt, lsr;
	int iobase = self->io.fir_base;

	register_bank(iobase, 0);

	IRDA_DEBUG(3, "%s\n", __FUNCTION__);
#if 0
	/* Disable Rx */
	register_bank(iobase, 0);
	outb(0x00, iobase + IRCC_LCR_B);
#endif
	register_bank(iobase, 0);
	outb(inb(iobase + IRCC_LSAR) & ~IRCC_LSAR_ADDRESS_MASK, iobase + IRCC_LSAR);
	lsr= inb(iobase + IRCC_LSR);
	msgcnt = inb(iobase + IRCC_LCR_B) & 0x08;

	IRDA_DEBUG(2, "%s: dma count = %d\n", __FUNCTION__,
		   get_dma_residue(self->io.dma));

	len = self->rx_buff.truesize - get_dma_residue(self->io.dma);

	/* Look for errors */
	if (lsr & (IRCC_LSR_FRAME_ERROR | IRCC_LSR_CRC_ERROR | IRCC_LSR_SIZE_ERROR)) {
		self->stats.rx_errors++;
		if (lsr & IRCC_LSR_FRAME_ERROR)
			self->stats.rx_frame_errors++;
		if (lsr & IRCC_LSR_CRC_ERROR)
			self->stats.rx_crc_errors++;
		if (lsr & IRCC_LSR_SIZE_ERROR)
			self->stats.rx_length_errors++;
		if (lsr & (IRCC_LSR_UNDERRUN | IRCC_LSR_OVERRUN))
			self->stats.rx_length_errors++;
		return;
	}

	/* Remove CRC */
	len -= self->io.speed < 4000000 ? 2 : 4;

	if (len < 2 || len > 2050) {
		IRDA_WARNING("%s(), bogus len=%d\n", __FUNCTION__, len);
		return;
	}
	IRDA_DEBUG(2, "%s: msgcnt = %d, len=%d\n", __FUNCTION__, msgcnt, len);

	skb = dev_alloc_skb(len + 1);
	if (!skb) {
		IRDA_WARNING("%s(), memory squeeze, dropping frame.\n",
			     __FUNCTION__);
		return;
	}
	/* Make sure IP header gets aligned */
	skb_reserve(skb, 1);

	memcpy(skb_put(skb, len), self->rx_buff.data, len);
	self->stats.rx_packets++;
	self->stats.rx_bytes += len;

	skb->dev = self->netdev;
	skb->mac.raw  = skb->data;
	skb->protocol = htons(ETH_P_IRDA);
	netif_rx(skb);
}

/*
 * Function smsc_ircc_sir_receive (self)
 *
 *    Receive one frame from the infrared port
 *
 */
static void smsc_ircc_sir_receive(struct smsc_ircc_cb *self)
{
	int boguscount = 0;
	int iobase;

	IRDA_ASSERT(self != NULL, return;);

	iobase = self->io.sir_base;

	/*
	 * Receive all characters in Rx FIFO, unwrap and unstuff them.
         * async_unwrap_char will deliver all found frames
	 */
	do {
		async_unwrap_char(self->netdev, &self->stats, &self->rx_buff,
				  inb(iobase + UART_RX));

		/* Make sure we don't stay here to long */
		if (boguscount++ > 32) {
			IRDA_DEBUG(2, "%s(), breaking!\n", __FUNCTION__);
			break;
		}
	} while (inb(iobase + UART_LSR) & UART_LSR_DR);
}


/*
 * Function smsc_ircc_interrupt (irq, dev_id, regs)
 *
 *    An interrupt from the chip has arrived. Time to do some work
 *
 */
static irqreturn_t smsc_ircc_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct net_device *dev = (struct net_device *) dev_id;
	struct smsc_ircc_cb *self;
	int iobase, iir, lcra, lsr;
	irqreturn_t ret = IRQ_NONE;

	if (dev == NULL) {
		printk(KERN_WARNING "%s: irq %d for unknown device.\n",
		       driver_name, irq);
		goto irq_ret;
	}

	self = netdev_priv(dev);
	IRDA_ASSERT(self != NULL, return IRQ_NONE;);

	/* Serialise the interrupt handler in various CPUs, stop Tx path */
	spin_lock(&self->lock);

	/* Check if we should use the SIR interrupt handler */
	if (self->io.speed <= SMSC_IRCC2_MAX_SIR_SPEED) {
		ret = smsc_ircc_interrupt_sir(dev);
		goto irq_ret_unlock;
	}

	iobase = self->io.fir_base;

	register_bank(iobase, 0);
	iir = inb(iobase + IRCC_IIR);
	if (iir == 0)
		goto irq_ret_unlock;
	ret = IRQ_HANDLED;

	/* Disable interrupts */
	outb(0, iobase + IRCC_IER);
	lcra = inb(iobase + IRCC_LCR_A);
	lsr = inb(iobase + IRCC_LSR);

	IRDA_DEBUG(2, "%s(), iir = 0x%02x\n", __FUNCTION__, iir);

	if (iir & IRCC_IIR_EOM) {
		if (self->io.direction == IO_RECV)
			smsc_ircc_dma_receive_complete(self);
		else
			smsc_ircc_dma_xmit_complete(self);

		smsc_ircc_dma_receive(self);
	}

	if (iir & IRCC_IIR_ACTIVE_FRAME) {
		/*printk(KERN_WARNING "%s(): Active Frame\n", __FUNCTION__);*/
	}

	/* Enable interrupts again */

	register_bank(iobase, 0);
	outb(IRCC_IER_ACTIVE_FRAME | IRCC_IER_EOM, iobase + IRCC_IER);

 irq_ret_unlock:
	spin_unlock(&self->lock);
 irq_ret:
	return ret;
}

/*
 * Function irport_interrupt_sir (irq, dev_id, regs)
 *
 *    Interrupt handler for SIR modes
 */
static irqreturn_t smsc_ircc_interrupt_sir(struct net_device *dev)
{
	struct smsc_ircc_cb *self = netdev_priv(dev);
	int boguscount = 0;
	int iobase;
	int iir, lsr;

	/* Already locked comming here in smsc_ircc_interrupt() */
	/*spin_lock(&self->lock);*/

	iobase = self->io.sir_base;

	iir = inb(iobase + UART_IIR) & UART_IIR_ID;
	if (iir == 0)
		return IRQ_NONE;
	while (iir) {
		/* Clear interrupt */
		lsr = inb(iobase + UART_LSR);

		IRDA_DEBUG(4, "%s(), iir=%02x, lsr=%02x, iobase=%#x\n",
			    __FUNCTION__, iir, lsr, iobase);

		switch (iir) {
		case UART_IIR_RLSI:
			IRDA_DEBUG(2, "%s(), RLSI\n", __FUNCTION__);
			break;
		case UART_IIR_RDI:
			/* Receive interrupt */
			smsc_ircc_sir_receive(self);
			break;
		case UART_IIR_THRI:
			if (lsr & UART_LSR_THRE)
				/* Transmitter ready for data */
				smsc_ircc_sir_write_wakeup(self);
			break;
		default:
			IRDA_DEBUG(0, "%s(), unhandled IIR=%#x\n",
				   __FUNCTION__, iir);
			break;
		}

		/* Make sure we don't stay here to long */
		if (boguscount++ > 100)
			break;

	        iir = inb(iobase + UART_IIR) & UART_IIR_ID;
	}
	/*spin_unlock(&self->lock);*/
	return IRQ_HANDLED;
}


#if 0 /* unused */
/*
 * Function ircc_is_receiving (self)
 *
 *    Return TRUE is we are currently receiving a frame
 *
 */
static int ircc_is_receiving(struct smsc_ircc_cb *self)
{
	int status = FALSE;
	/* int iobase; */

	IRDA_DEBUG(1, "%s\n", __FUNCTION__);

	IRDA_ASSERT(self != NULL, return FALSE;);

	IRDA_DEBUG(0, "%s: dma count = %d\n", __FUNCTION__,
		   get_dma_residue(self->io.dma));

	status = (self->rx_buff.state != OUTSIDE_FRAME);

	return status;
}
#endif /* unused */


/*
 * Function smsc_ircc_net_open (dev)
 *
 *    Start the device
 *
 */
static int smsc_ircc_net_open(struct net_device *dev)
{
	struct smsc_ircc_cb *self;
	char hwname[16];
	unsigned long flags;

	IRDA_DEBUG(1, "%s\n", __FUNCTION__);

	IRDA_ASSERT(dev != NULL, return -1;);
	self = netdev_priv(dev);
	IRDA_ASSERT(self != NULL, return 0;);

	if (request_irq(self->io.irq, smsc_ircc_interrupt, 0, dev->name,
			(void *) dev)) {
		IRDA_DEBUG(0, "%s(), unable to allocate irq=%d\n",
			   __FUNCTION__, self->io.irq);
		return -EAGAIN;
	}

	spin_lock_irqsave(&self->lock, flags);
	/*smsc_ircc_sir_start(self);*/
	self->io.speed = 0;
	smsc_ircc_change_speed(self, SMSC_IRCC2_C_IRDA_FALLBACK_SPEED);
	spin_unlock_irqrestore(&self->lock, flags);

	/* Give self a hardware name */
	/* It would be cool to offer the chip revision here - Jean II */
	sprintf(hwname, "SMSC @ 0x%03x", self->io.fir_base);

	/*
	 * Open new IrLAP layer instance, now that everything should be
	 * initialized properly
	 */
	self->irlap = irlap_open(dev, &self->qos, hwname);

	/*
	 * Always allocate the DMA channel after the IRQ,
	 * and clean up on failure.
	 */
	if (request_dma(self->io.dma, dev->name)) {
		smsc_ircc_net_close(dev);

		IRDA_WARNING("%s(), unable to allocate DMA=%d\n",
			     __FUNCTION__, self->io.dma);
		return -EAGAIN;
	}

	netif_start_queue(dev);

	return 0;
}

/*
 * Function smsc_ircc_net_close (dev)
 *
 *    Stop the device
 *
 */
static int smsc_ircc_net_close(struct net_device *dev)
{
	struct smsc_ircc_cb *self;

	IRDA_DEBUG(1, "%s\n", __FUNCTION__);

	IRDA_ASSERT(dev != NULL, return -1;);
	self = netdev_priv(dev);
	IRDA_ASSERT(self != NULL, return 0;);

	/* Stop device */
	netif_stop_queue(dev);

	/* Stop and remove instance of IrLAP */
	if (self->irlap)
		irlap_close(self->irlap);
	self->irlap = NULL;

	free_irq(self->io.irq, dev);
	disable_dma(self->io.dma);
	free_dma(self->io.dma);

	return 0;
}

static int smsc_ircc_suspend(struct device *dev, pm_message_t state, u32 level)
{
	struct smsc_ircc_cb *self = dev_get_drvdata(dev);

	IRDA_MESSAGE("%s, Suspending\n", driver_name);

	if (level == SUSPEND_DISABLE && !self->io.suspended) {
		smsc_ircc_net_close(self->netdev);
		self->io.suspended = 1;
	}

	return 0;
}

static int smsc_ircc_resume(struct device *dev, u32 level)
{
	struct smsc_ircc_cb *self = dev_get_drvdata(dev);

	if (level == RESUME_ENABLE && self->io.suspended) {

		smsc_ircc_net_open(self->netdev);
		self->io.suspended = 0;

		IRDA_MESSAGE("%s, Waking up\n", driver_name);
	}
	return 0;
}

/*
 * Function smsc_ircc_close (self)
 *
 *    Close driver instance
 *
 */
static int __exit smsc_ircc_close(struct smsc_ircc_cb *self)
{
	int iobase;
	unsigned long flags;

	IRDA_DEBUG(1, "%s\n", __FUNCTION__);

	IRDA_ASSERT(self != NULL, return -1;);

	platform_device_unregister(self->pldev);

	/* Remove netdevice */
	unregister_netdev(self->netdev);

	/* Make sure the irq handler is not exectuting */
	spin_lock_irqsave(&self->lock, flags);

	/* Stop interrupts */
	iobase = self->io.fir_base;
	register_bank(iobase, 0);
	outb(0, iobase + IRCC_IER);
	outb(IRCC_MASTER_RESET, iobase + IRCC_MASTER);
	outb(0x00, iobase + IRCC_MASTER);
#if 0
	/* Reset to SIR mode */
	register_bank(iobase, 1);
        outb(IRCC_CFGA_IRDA_SIR_A|IRCC_CFGA_TX_POLARITY, iobase + IRCC_SCE_CFGA);
        outb(IRCC_CFGB_IR, iobase + IRCC_SCE_CFGB);
#endif
	spin_unlock_irqrestore(&self->lock, flags);

	/* Release the PORTS that this driver is using */
	IRDA_DEBUG(0, "%s(), releasing 0x%03x\n",  __FUNCTION__,
		   self->io.fir_base);

	release_region(self->io.fir_base, self->io.fir_ext);

	IRDA_DEBUG(0, "%s(), releasing 0x%03x\n", __FUNCTION__,
		   self->io.sir_base);

	release_region(self->io.sir_base, self->io.sir_ext);

	if (self->tx_buff.head)
		dma_free_coherent(NULL, self->tx_buff.truesize,
				  self->tx_buff.head, self->tx_buff_dma);

	if (self->rx_buff.head)
		dma_free_coherent(NULL, self->rx_buff.truesize,
				  self->rx_buff.head, self->rx_buff_dma);

	free_netdev(self->netdev);

	return 0;
}

static void __exit smsc_ircc_cleanup(void)
{
	int i;

	IRDA_DEBUG(1, "%s\n", __FUNCTION__);

	for (i = 0; i < 2; i++) {
		if (dev_self[i])
			smsc_ircc_close(dev_self[i]);
	}

	driver_unregister(&smsc_ircc_driver);
}

/*
 *	Start SIR operations
 *
 * This function *must* be called with spinlock held, because it may
 * be called from the irq handler (via smsc_ircc_change_speed()). - Jean II
 */
void smsc_ircc_sir_start(struct smsc_ircc_cb *self)
{
	struct net_device *dev;
	int fir_base, sir_base;

	IRDA_DEBUG(3, "%s\n", __FUNCTION__);

	IRDA_ASSERT(self != NULL, return;);
	dev = self->netdev;
	IRDA_ASSERT(dev != NULL, return;);
	dev->hard_start_xmit = &smsc_ircc_hard_xmit_sir;

	fir_base = self->io.fir_base;
	sir_base = self->io.sir_base;

	/* Reset everything */
	outb(IRCC_MASTER_RESET, fir_base + IRCC_MASTER);

	#if SMSC_IRCC2_C_SIR_STOP
	/*smsc_ircc_sir_stop(self);*/
	#endif