staging: comedi: mite: introduce mite_ack_linkc()

Introduce a helper function to handle the ack of a LINKC interrupt.
Tidy up the drivers that use the new helper.

The extra check for CHSR_INT in the ni_pcidio driver is not necessary.
This bit will be set if any of the interrupt sources, including CHSR_LINKC,
have generated an interrupt. Remove the extra check.

The mite_get_status() function is now only used by the mite driver.
Make it static and remove the export.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/mite.c

@@ -622,7 +622,7 @@ int mite_sync_output_dma(struct mite_channel *mite_chan,
 }
 EXPORT_SYMBOL_GPL(mite_sync_output_dma);
 
-unsigned int mite_get_status(struct mite_channel *mite_chan)
+static unsigned int mite_get_status(struct mite_channel *mite_chan)
 {
 	struct mite_struct *mite = mite_chan->mite;
 	unsigned int status;
@@ -639,7 +639,20 @@ unsigned int mite_get_status(struct mite_channel *mite_chan)
 	spin_unlock_irqrestore(&mite->lock, flags);
 	return status;
 }
-EXPORT_SYMBOL_GPL(mite_get_status);
+
+unsigned int mite_ack_linkc(struct mite_channel *mite_chan)
+{
+	struct mite_struct *mite = mite_chan->mite;
+	unsigned int status;
+
+	status = mite_get_status(mite_chan);
+	if (status & CHSR_LINKC)
+		writel(CHOR_CLRLC,
+		       mite->mite_io_addr + MITE_CHOR(mite_chan->channel));
+
+	return status;
+}
+EXPORT_SYMBOL_GPL(mite_ack_linkc);
 
 int mite_done(struct mite_channel *mite_chan)
 {

drivers/staging/comedi/drivers/mite.h

@@ -97,7 +97,7 @@ int mite_sync_input_dma(struct mite_channel *mite_chan,
 int mite_sync_output_dma(struct mite_channel *mite_chan,
 			 struct comedi_subdevice *s);
 u32 mite_bytes_in_transit(struct mite_channel *mite_chan);
-unsigned int mite_get_status(struct mite_channel *mite_chan);
+unsigned int mite_ack_linkc(struct mite_channel *mite_chan);
 int mite_done(struct mite_channel *mite_chan);
 
 void mite_prep_dma(struct mite_channel *mite_chan,

drivers/staging/comedi/drivers/ni_mio_common.c

@@ -3697,13 +3697,7 @@ static void handle_cdio_interrupt(struct comedi_device *dev)
 
 	spin_lock_irqsave(&devpriv->mite_channel_lock, flags);
 	if (devpriv->cdo_mite_chan) {
-		unsigned int cdo_mite_status =
+		mite_ack_linkc(devpriv->cdo_mite_chan);
-		    mite_get_status(devpriv->cdo_mite_chan);
-		if (cdo_mite_status & CHSR_LINKC) {
-			writel(CHOR_CLRLC,
-			       devpriv->mite->mite_io_addr +
-			       MITE_CHOR(devpriv->cdo_mite_chan->channel));
-		}
 		mite_sync_output_dma(devpriv->cdo_mite_chan, s);
 	}
 	spin_unlock_irqrestore(&devpriv->mite_channel_lock, flags);
@@ -5222,22 +5216,10 @@ static irqreturn_t ni_E_interrupt(int irq, void *d)
 		unsigned long flags_too;
 
 		spin_lock_irqsave(&devpriv->mite_channel_lock, flags_too);
-		if (devpriv->ai_mite_chan) {
+		if (devpriv->ai_mite_chan)
-			ai_mite_status = mite_get_status(devpriv->ai_mite_chan);
+			ai_mite_status = mite_ack_linkc(devpriv->ai_mite_chan);
-			if (ai_mite_status & CHSR_LINKC)
+		if (devpriv->ao_mite_chan)
-				writel(CHOR_CLRLC,
+			ao_mite_status = mite_ack_linkc(devpriv->ao_mite_chan);
-				       devpriv->mite->mite_io_addr +
-				       MITE_CHOR(devpriv->
-						 ai_mite_chan->channel));
-		}
-		if (devpriv->ao_mite_chan) {
-			ao_mite_status = mite_get_status(devpriv->ao_mite_chan);
-			if (ao_mite_status & CHSR_LINKC)
-				writel(CHOR_CLRLC,
-				       devpriv->mite->mite_io_addr +
-				       MITE_CHOR(devpriv->
-						 ao_mite_chan->channel));
-		}
 		spin_unlock_irqrestore(&devpriv->mite_channel_lock, flags_too);
 	}
 #endif

drivers/staging/comedi/drivers/ni_pcidio.c

@@ -381,12 +381,10 @@ static irqreturn_t nidio_interrupt(int irq, void *d)
 	struct nidio96_private *devpriv = dev->private;
 	struct comedi_subdevice *s = dev->read_subdev;
 	struct comedi_async *async = s->async;
-	struct mite_struct *mite = devpriv->mite;
 	unsigned int auxdata;
 	int flags;
 	int status;
 	int work = 0;
-	unsigned int m_status = 0;
 
 	/* interrupcions parasites */
 	if (!dev->attached) {
@@ -401,14 +399,10 @@ static irqreturn_t nidio_interrupt(int irq, void *d)
 	flags = readb(dev->mmio + Group_1_Flags);
 
 	spin_lock(&devpriv->mite_channel_lock);
-	if (devpriv->di_mite_chan)
+	if (devpriv->di_mite_chan) {
-		m_status = mite_get_status(devpriv->di_mite_chan);
+		unsigned int m_status = mite_ack_linkc(devpriv->di_mite_chan);
 
-	if (m_status & CHSR_INT) {
 		if (m_status & CHSR_LINKC) {
-			writel(CHOR_CLRLC,
-			       mite->mite_io_addr +
-			       MITE_CHOR(devpriv->di_mite_chan->channel));
 			mite_sync_input_dma(devpriv->di_mite_chan, s);
 			/* XXX need to byteswap */
 		}

drivers/staging/comedi/drivers/ni_tiocmd.c

@@ -400,7 +400,6 @@ void ni_tio_handle_interrupt(struct ni_gpct *counter,
 			     struct comedi_subdevice *s)
 {
 	unsigned int cidx = counter->counter_index;
-	unsigned int gpct_mite_status;
 	unsigned long flags;
 	int gate_error;
 	int tc_error;
@@ -429,16 +428,10 @@ void ni_tio_handle_interrupt(struct ni_gpct *counter,
 		break;
 	}
 	spin_lock_irqsave(&counter->lock, flags);
-	if (!counter->mite_chan) {
+	if (counter->mite_chan) {
-		spin_unlock_irqrestore(&counter->lock, flags);
+		mite_ack_linkc(counter->mite_chan);
-		return;
+		mite_sync_input_dma(counter->mite_chan, s);
 	}
-	gpct_mite_status = mite_get_status(counter->mite_chan);
-	if (gpct_mite_status & CHSR_LINKC)
-		writel(CHOR_CLRLC,
-		       counter->mite_chan->mite->mite_io_addr +
-		       MITE_CHOR(counter->mite_chan->channel));
-	mite_sync_input_dma(counter->mite_chan, s);
 	spin_unlock_irqrestore(&counter->lock, flags);
 }
 EXPORT_SYMBOL_GPL(ni_tio_handle_interrupt);