staging: comedi: pcl818: remove 'ai_mode' from private data

This member of the private data is not needed. We can determine the
interrupt mode based on the 'dma' and 'usefifo' members.

Refactor the interrupt handler and the (*cancel) function to not use
the 'ai_mode' and remove the setting of this member in the (*do_cmd)
heler functions.
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/pcl818.c

@@ -163,14 +163,6 @@ A word or two about DMA. Driver support DMA operations at two ways:
 #define PCL818_FI_DATALO 23
 #define PCL818_FI_DATAHI 24
 
-/* type of interrupt handler */
-#define INT_TYPE_AI1_INT 1
-#define INT_TYPE_AI1_DMA 2
-#define INT_TYPE_AI1_FIFO 3
-#define INT_TYPE_AI3_INT 4
-#define INT_TYPE_AI3_DMA 5
-#define INT_TYPE_AI3_FIFO 6
-
 #define MAGIC_DMA_WORD 0x5a5a
 
 static const struct comedi_lrange range_pcl818h_ai = {
@@ -320,7 +312,6 @@ struct pcl818_private {
 	unsigned long last_dma_run;	/*  how many bytes we must transfer on last DMA page */
 	unsigned int ns_min;	/*  manimal allowed delay between samples (in us) for actual card */
 	int i8253_osc_base;	/*  1/frequency of on board oscilator in ns */
-	int ai_mode;		/*  who now uses IRQ - 1=AI1 int, 2=AI1 dma, 3=AI3 int, 4AI3 dma */
 	int ai_act_scan;	/*  how many scans we finished */
 	int ai_act_chan;	/*  actual position in actual scan */
 	unsigned int act_chanlist[16];	/*  MUX setting for actual AI operations */
@@ -732,8 +723,7 @@ static irqreturn_t interrupt_pcl818(int irq, void *d)
 	struct pcl818_private *devpriv = dev->private;
 	struct comedi_subdevice *s = dev->read_subdev;
 
-	if (!dev->attached || !devpriv->ai_cmd_running ||
-	    !devpriv->ai_mode) {
+	if (!dev->attached || !devpriv->ai_cmd_running) {
 		outb(0, dev->iobase + PCL818_CLRINT);
 		return IRQ_HANDLED;
 	}
@@ -751,38 +741,23 @@ static irqreturn_t interrupt_pcl818(int irq, void *d)
 		return IRQ_HANDLED;
 	}
 
-	switch (devpriv->ai_mode) {
-	case INT_TYPE_AI1_DMA:
-	case INT_TYPE_AI3_DMA:
+	if (devpriv->dma)
 		return interrupt_pcl818_ai_mode13_dma(irq, d);
-	case INT_TYPE_AI1_INT:
-	case INT_TYPE_AI3_INT:
-		return interrupt_pcl818_ai_mode13_int(irq, d);
-	case INT_TYPE_AI1_FIFO:
-	case INT_TYPE_AI3_FIFO:
+	else if (devpriv->usefifo)
 		return interrupt_pcl818_ai_mode13_fifo(irq, d);
-	default:
-		break;
-	}
-
-	outb(0, dev->iobase + PCL818_CLRINT);
-	return IRQ_HANDLED;
+	else
+		return interrupt_pcl818_ai_mode13_int(irq, d);
 }
 
 static void pcl818_ai_mode13dma_int(int mode, struct comedi_device *dev,
 				    struct comedi_subdevice *s)
 {
-	struct pcl818_private *devpriv = dev->private;
-
 	pcl818_ai_setup_dma(dev, s);
 
-	if (mode == 1) {
-		devpriv->ai_mode = INT_TYPE_AI1_DMA;
-		outb(0x87 | (dev->irq << 4), dev->iobase + PCL818_CONTROL);	/* Pacer+IRQ+DMA */
-	} else {
-		devpriv->ai_mode = INT_TYPE_AI3_DMA;
-		outb(0x86 | (dev->irq << 4), dev->iobase + PCL818_CONTROL);	/* Ext trig+IRQ+DMA */
-	}
+	if (mode == 1)	/* Pacer+IRQ+DMA */
+		outb(0x87 | (dev->irq << 4), dev->iobase + PCL818_CONTROL);
+	else		/* Ext trig+IRQ+DMA */
+		outb(0x86 | (dev->irq << 4), dev->iobase + PCL818_CONTROL);
 }
 
 static int pcl818_ai_cmd_mode(int mode, struct comedi_device *dev,
@@ -821,31 +796,22 @@ static int pcl818_ai_cmd_mode(int mode, struct comedi_device *dev,
 	case 0:
 		if (!devpriv->usefifo) {
 			/* IRQ */
-			if (mode == 1) {
-				devpriv->ai_mode = INT_TYPE_AI1_INT;
-				/* Pacer+IRQ */
+			if (mode == 1)	/* Pacer+IRQ */
 				outb(0x83 | (dev->irq << 4),
 				     dev->iobase + PCL818_CONTROL);
-			} else {
-				devpriv->ai_mode = INT_TYPE_AI3_INT;
-				/* Ext trig+IRQ */
+			else		/* Ext trig+IRQ */
 				outb(0x82 | (dev->irq << 4),
 				     dev->iobase + PCL818_CONTROL);
-			}
 		} else {
 			/* FIFO */
 			/* enable FIFO */
 			outb(1, dev->iobase + PCL818_FI_ENABLE);
-			if (mode == 1) {
-				devpriv->ai_mode = INT_TYPE_AI1_FIFO;
-				/* Pacer */
+			if (mode == 1)	/* Pacer */
 				outb(0x03, dev->iobase + PCL818_CONTROL);
-			} else {
-				devpriv->ai_mode = INT_TYPE_AI3_FIFO;
+			else		/* Ext trig */
 				outb(0x02, dev->iobase + PCL818_CONTROL);
 		}
 	}
-	}
 
 	pcl818_start_pacer(dev, mode == 1);
 
@@ -1047,9 +1013,7 @@ static int pcl818_ai_cancel(struct comedi_device *dev,
 	if (!devpriv->ai_cmd_running)
 		return 0;
 
-	switch (devpriv->ai_mode) {
-	case INT_TYPE_AI1_DMA:
-	case INT_TYPE_AI3_DMA:
+	if (devpriv->dma) {
 		if (cmd->stop_src == TRIG_NONE ||
 		    (cmd->stop_src == TRIG_COUNT && devpriv->ai_act_scan > 0)) {
 			if (!devpriv->ai_cmd_canceled) {
@@ -1062,10 +1026,8 @@ static int pcl818_ai_cancel(struct comedi_device *dev,
 			}
 		}
 		disable_dma(devpriv->dma);
-	case INT_TYPE_AI1_INT:
-	case INT_TYPE_AI3_INT:
-	case INT_TYPE_AI1_FIFO:
-	case INT_TYPE_AI3_FIFO:
+	}
+
 	outb(inb(dev->iobase + PCL818_CONTROL) & 0x73,
 	     dev->iobase + PCL818_CONTROL);	/* Stop A/D */
 	udelay(1);
@@ -1080,10 +1042,7 @@ static int pcl818_ai_cancel(struct comedi_device *dev,
 		outb(0, dev->iobase + PCL818_FI_ENABLE);
 	}
 	devpriv->ai_cmd_running = 0;
-		devpriv->ai_mode = 0;
 	devpriv->ai_cmd_canceled = 0;
-		break;
-	}
 
 	return 0;
 }