staging: comedi: ni_labpc_common: introduce labpc_ao_write()

Introduce a helper function to write a value to a given DAC channel.

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>

diff --git a/drivers/staging/comedi/drivers/ni_labpc_common.c b/drivers/staging/comedi/drivers/ni_labpc_common.c
index 548d3df08525515dd2a1206492cbe72b2ce40b83..354c33e6f21ccfa0da75624c0b646df8a40ebd2f 100644 (file)
--- a/drivers/staging/comedi/drivers/ni_labpc_common.c
+++ b/drivers/staging/comedi/drivers/ni_labpc_common.c
@@ -918,6 +918,18 @@ static irqreturn_t labpc_interrupt(int irq, void *d)
        return IRQ_HANDLED;
 }
 
+static void labpc_ao_write(struct comedi_device *dev,
+                          struct comedi_subdevice *s,
+                          unsigned int chan, unsigned int val)
+{
+       struct labpc_private *devpriv = dev->private;
+
+       devpriv->write_byte(dev, val & 0xff, DAC_LSB_REG(chan));
+       devpriv->write_byte(dev, (val >> 8) & 0xff, DAC_MSB_REG(chan));
+
+       devpriv->ao_value[chan] = val;
+}
+
 static int labpc_ao_insn_write(struct comedi_device *dev,
                               struct comedi_subdevice *s,
                               struct comedi_insn *insn,
@@ -927,7 +939,6 @@ static int labpc_ao_insn_write(struct comedi_device *dev,
        struct labpc_private *devpriv = dev->private;
        int channel, range;
        unsigned long flags;
-       int lsb, msb;
 
        channel = CR_CHAN(insn->chanspec);
 
@@ -950,13 +961,7 @@ static int labpc_ao_insn_write(struct comedi_device *dev,
                devpriv->write_byte(dev, devpriv->cmd6, CMD6_REG);
        }
        /* send data */
-       lsb = data[0] & 0xff;
-       msb = (data[0] >> 8) & 0xff;
-       devpriv->write_byte(dev, lsb, DAC_LSB_REG(channel));
-       devpriv->write_byte(dev, msb, DAC_MSB_REG(channel));
-
-       /* remember value for readback */
-       devpriv->ao_value[channel] = data[0];
+       labpc_ao_write(dev, s, channel, data[0]);
 
        return 1;
 }
@@ -1300,15 +1305,8 @@ int labpc_common_attach(struct comedi_device *dev,
                s->insn_write   = labpc_ao_insn_write;
 
                /* initialize analog outputs to a known value */
-               for (i = 0; i < s->n_chan; i++) {
-                       short lsb, msb;
-
-                       devpriv->ao_value[i] = s->maxdata / 2;
-                       lsb = devpriv->ao_value[i] & 0xff;
-                       msb = (devpriv->ao_value[i] >> 8) & 0xff;
-                       devpriv->write_byte(dev, lsb, DAC_LSB_REG(i));
-                       devpriv->write_byte(dev, msb, DAC_MSB_REG(i));
-               }
+               for (i = 0; i < s->n_chan; i++)
+                       labpc_ao_write(dev, s, i, s->maxdata / 2);
        } else {
                s->type         = COMEDI_SUBD_UNUSED;
        }