staging: comedi: adv_pci1710: tidy up pci1710_reset()

Change the return type to void, this function always succeeds and the
caller does not check the return value anyway.

Fix the initial programming of the control register. The SW bit enables
the software trigger and should not be set here. Setting CNT0 selects the
external clock source for counter 0 (the user counter). It makes more
sense to select the internal 1 MHz clock.

Remove the unnecessary initialization of the private data members. This
function is only called during the (*auto_attach) after the private
data was kzalloc'ed.

Remove the redundant clearing of the A/D FIFO and pending interrupts.
Just do it once.
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/adv_pci1710.c

@@ -711,29 +711,29 @@ static int pci1710_counter_insn_config(struct comedi_device *dev,
 	return insn->n;
 }
 
-static int pci1710_reset(struct comedi_device *dev)
+static void pci1710_reset(struct comedi_device *dev)
 {
 	const struct boardtype *board = dev->board_ptr;
-	struct pci1710_private *devpriv = dev->private;
 
-	/* Software trigger, CNT0=external */
-	devpriv->ctrl = PCI171X_CTRL_SW | PCI171X_CTRL_CNT0;
-	/* reset any operations */
-	outw(devpriv->ctrl, dev->iobase + PCI171X_CTRL_REG);
+	/*
+	 * Disable A/D triggers and interrupt sources, set counter 0
+	 * to use internal 1 MHz clock.
+	 */
+	outw(0, dev->iobase + PCI171X_CTRL_REG);
+
+	/* clear A/D FIFO and any pending interrutps */
 	outb(0, dev->iobase + PCI171X_CLRFIFO_REG);
 	outb(0, dev->iobase + PCI171X_CLRINT_REG);
-	devpriv->da_ranges = 0;
+
 	if (board->has_ao) {
 		/* set DACs to 0..5V and outputs to 0V */
-		outb(devpriv->da_ranges, dev->iobase + PCI171X_DAREF_REG);
+		outb(0, dev->iobase + PCI171X_DAREF_REG);
 		outw(0, dev->iobase + PCI171X_DA_REG(0));
 		outw(0, dev->iobase + PCI171X_DA_REG(1));
 	}
-	outw(0, dev->iobase + PCI171X_DO_REG);	/*  digital outputs to 0 */
-	outb(0, dev->iobase + PCI171X_CLRFIFO_REG);
-	outb(0, dev->iobase + PCI171X_CLRINT_REG);
 
-	return 0;
+	/* set digital outputs to 0 */
+	outw(0, dev->iobase + PCI171X_DO_REG);
 }
 
 static int pci1710_auto_attach(struct comedi_device *dev,