staging: comedi: amplc_pci224: factor out the 'start pacer' code

To clarify the analog output (*do_cmd) function, factor out the
code that starts the pacer.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/amplc_pci224.c

@@ -901,65 +901,11 @@ pci224_ao_cmdtest(struct comedi_device *dev, struct comedi_subdevice *s,
 	return 0;
 }
 
-/*
- * 'do_cmd' function for AO subdevice.
- */
-static int pci224_ao_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
+static void pci224_ao_start_pacer(struct comedi_device *dev,
+				  struct comedi_subdevice *s)
 {
 	struct pci224_private *devpriv = dev->private;
 	struct comedi_cmd *cmd = &s->async->cmd;
-	int range;
-	unsigned int i, j;
-	unsigned int ch;
-	unsigned int rank;
-	unsigned long flags;
-
-	/* Cannot handle null/empty chanlist. */
-	if (cmd->chanlist == NULL || cmd->chanlist_len == 0)
-		return -EINVAL;
-
-
-	/* Determine which channels are enabled and their load order.  */
-	devpriv->ao_enab = 0;
-
-	for (i = 0; i < cmd->chanlist_len; i++) {
-		ch = CR_CHAN(cmd->chanlist[i]);
-		devpriv->ao_enab |= 1U << ch;
-		rank = 0;
-		for (j = 0; j < cmd->chanlist_len; j++) {
-			if (CR_CHAN(cmd->chanlist[j]) < ch)
-				rank++;
-
-		}
-		devpriv->ao_scan_order[rank] = i;
-	}
-
-	/* Set enabled channels. */
-	outw(devpriv->ao_enab, dev->iobase + PCI224_DACCEN);
-
-	/* Determine range and polarity.  All channels the same.  */
-	range = CR_RANGE(cmd->chanlist[0]);
-
-	/*
-	 * Set DAC range and polarity.
-	 * Set DAC scan trigger source to 'none'.
-	 * Set DAC FIFO interrupt trigger level to 'not half full'.
-	 * Reset DAC FIFO.
-	 *
-	 * N.B. DAC FIFO interrupts are currently disabled.
-	 */
-	devpriv->daccon = COMBINE(devpriv->daccon,
-				  (devpriv->
-				   hwrange[range] | PCI224_DACCON_TRIG_NONE |
-				   PCI224_DACCON_FIFOINTR_NHALF),
-				  (PCI224_DACCON_POLAR_MASK |
-				   PCI224_DACCON_VREF_MASK |
-				   PCI224_DACCON_TRIG_MASK |
-				   PCI224_DACCON_FIFOINTR_MASK));
-	outw(devpriv->daccon | PCI224_DACCON_FIFORESET,
-	     dev->iobase + PCI224_DACCON);
-
-	if (cmd->scan_begin_src == TRIG_TIMER) {
 	unsigned int div1, div2, round;
 	unsigned int ns = cmd->scan_begin_arg;
 	int round_mode = cmd->flags & TRIG_ROUND_MASK;
@@ -1024,7 +970,65 @@ static int pci224_ao_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 	}
 	/* Load Z2-0 mode (2) and counter (div2). */
 	i8254_load(devpriv->iobase1 + PCI224_Z2_CT0, 0, 0, div2, 2);
+}
+
+static int pci224_ao_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
+{
+	struct pci224_private *devpriv = dev->private;
+	struct comedi_cmd *cmd = &s->async->cmd;
+	int range;
+	unsigned int i, j;
+	unsigned int ch;
+	unsigned int rank;
+	unsigned long flags;
+
+	/* Cannot handle null/empty chanlist. */
+	if (cmd->chanlist == NULL || cmd->chanlist_len == 0)
+		return -EINVAL;
+
+
+	/* Determine which channels are enabled and their load order.  */
+	devpriv->ao_enab = 0;
+
+	for (i = 0; i < cmd->chanlist_len; i++) {
+		ch = CR_CHAN(cmd->chanlist[i]);
+		devpriv->ao_enab |= 1U << ch;
+		rank = 0;
+		for (j = 0; j < cmd->chanlist_len; j++) {
+			if (CR_CHAN(cmd->chanlist[j]) < ch)
+				rank++;
+
 		}
+		devpriv->ao_scan_order[rank] = i;
+	}
+
+	/* Set enabled channels. */
+	outw(devpriv->ao_enab, dev->iobase + PCI224_DACCEN);
+
+	/* Determine range and polarity.  All channels the same.  */
+	range = CR_RANGE(cmd->chanlist[0]);
+
+	/*
+	 * Set DAC range and polarity.
+	 * Set DAC scan trigger source to 'none'.
+	 * Set DAC FIFO interrupt trigger level to 'not half full'.
+	 * Reset DAC FIFO.
+	 *
+	 * N.B. DAC FIFO interrupts are currently disabled.
+	 */
+	devpriv->daccon = COMBINE(devpriv->daccon,
+				  (devpriv->
+				   hwrange[range] | PCI224_DACCON_TRIG_NONE |
+				   PCI224_DACCON_FIFOINTR_NHALF),
+				  (PCI224_DACCON_POLAR_MASK |
+				   PCI224_DACCON_VREF_MASK |
+				   PCI224_DACCON_TRIG_MASK |
+				   PCI224_DACCON_FIFOINTR_MASK));
+	outw(devpriv->daccon | PCI224_DACCON_FIFORESET,
+	     dev->iobase + PCI224_DACCON);
+
+	if (cmd->scan_begin_src == TRIG_TIMER)
+		pci224_ao_start_pacer(dev, s);
 
 	/*
 	 * Sort out end of acquisition.