staging: comedi: pcl818: sample types are unsigned

Sample values in comedi are generally represented as unsigned values.
Change the interrupt data transfer functions in the "pcl818" module to
use unsigned types for consistency.

Also remove the `short *ai_data` member of `struct pcl818_private` as it
is only assigned to and otherwise unused.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/pcl818.c

@@ -289,7 +289,6 @@ struct pcl818_private {
 	unsigned int *ai_chanlist;	/*  actaul chanlist */
 	unsigned int ai_flags;	/*  flaglist */
 	unsigned int ai_data_len;	/*  len of data buffer */
-	short *ai_data;		/*  data buffer */
 	unsigned int ai_timer1;	/*  timers */
 	unsigned int ai_timer2;
 	struct comedi_subdevice *sub_ai;	/*  ptr to AI subdevice */
@@ -443,7 +442,7 @@ static irqreturn_t interrupt_pcl818_ai_mode13_int(int irq, void *d)
 	struct comedi_device *dev = d;
 	struct pcl818_private *devpriv = dev->private;
 	struct comedi_subdevice *s = &dev->subdevices[0];
-	int low;
+	unsigned char low;
 	int timeout = 50;	/* wait max 50us */
 
 	while (timeout--) {
@@ -505,7 +504,7 @@ static irqreturn_t interrupt_pcl818_ai_mode13_dma(int irq, void *d)
 	struct comedi_subdevice *s = &dev->subdevices[0];
 	int i, len, bufptr;
 	unsigned long flags;
-	short *ptr;
+	unsigned short *ptr;
 
 	disable_dma(devpriv->dma);
 	devpriv->next_dma_buf = 1 - devpriv->next_dma_buf;
@@ -528,7 +527,7 @@ static irqreturn_t interrupt_pcl818_ai_mode13_dma(int irq, void *d)
 
 	devpriv->dma_runs_to_end--;
 	outb(0, dev->iobase + PCL818_CLRINT);	/* clear INT request */
-	ptr = (short *)devpriv->dmabuf[1 - devpriv->next_dma_buf];
+	ptr = (unsigned short *)devpriv->dmabuf[1 - devpriv->next_dma_buf];
 
 	len = devpriv->hwdmasize[0] >> 1;
 	bufptr = 0;
@@ -582,7 +581,8 @@ static irqreturn_t interrupt_pcl818_ai_mode13_fifo(int irq, void *d)
 	struct comedi_device *dev = d;
 	struct pcl818_private *devpriv = dev->private;
 	struct comedi_subdevice *s = &dev->subdevices[0];
-	int i, len, lo;
+	int i, len;
+	unsigned char lo;
 
 	outb(0, dev->iobase + PCL818_FI_INTCLR);	/*  clear fifo int request */
 
@@ -1072,7 +1072,6 @@ static int ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 	devpriv->ai_chanlist = cmd->chanlist;
 	devpriv->ai_flags = cmd->flags;
 	devpriv->ai_data_len = s->async->prealloc_bufsz;
-	devpriv->ai_data = s->async->prealloc_buf;
 	devpriv->ai_timer1 = 0;
 	devpriv->ai_timer2 = 0;