staging: comedi: pcl711: use comedi_subdevice 'readback'

Use the new comedi_subdevice 'readback' member and the core provided
(*insn_read) for the readback of the analog output subdevice channels.

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/pcl711.c b/drivers/staging/comedi/drivers/pcl711.c
index 40f9136f0bb676e03a703a657b054a62dffcb792..094e5138edb2015c204df6542f5e00648e7442ed 100644 (file)
--- a/drivers/staging/comedi/drivers/pcl711.c
+++ b/drivers/staging/comedi/drivers/pcl711.c
@@ -157,7 +157,6 @@ static const struct pcl711_board boardtypes[] = {
 
 struct pcl711_private {
        unsigned int ntrig;
-       unsigned int ao_readback[2];
        unsigned int divisor1;
        unsigned int divisor2;
 };
@@ -410,31 +409,15 @@ static int pcl711_ao_insn_write(struct comedi_device *dev,
                                struct comedi_insn *insn,
                                unsigned int *data)
 {
-       struct pcl711_private *devpriv = dev->private;
        unsigned int chan = CR_CHAN(insn->chanspec);
-       unsigned int val = devpriv->ao_readback[chan];
+       unsigned int val = s->readback[chan];
        int i;
 
        for (i = 0; i < insn->n; i++) {
                val = data[i];
                pcl711_ao_write(dev, chan, val);
        }
-       devpriv->ao_readback[chan] = val;
-
-       return insn->n;
-}
-
-static int pcl711_ao_insn_read(struct comedi_device *dev,
-                              struct comedi_subdevice *s,
-                              struct comedi_insn *insn,
-                              unsigned int *data)
-{
-       struct pcl711_private *devpriv = dev->private;
-       unsigned int chan = CR_CHAN(insn->chanspec);
-       int i;
-
-       for (i = 0; i < insn->n; i++)
-               data[i] = devpriv->ao_readback[chan];
+       s->readback[chan] = val;
 
        return insn->n;
 }
@@ -527,7 +510,11 @@ static int pcl711_attach(struct comedi_device *dev, struct comedi_devconfig *it)
        s->maxdata      = 0xfff;
        s->range_table  = &range_bipolar5;
        s->insn_write   = pcl711_ao_insn_write;
-       s->insn_read    = pcl711_ao_insn_read;
+       s->insn_read    = comedi_readback_insn_read;
+
+       ret = comedi_alloc_subdev_readback(s);
+       if (ret)
+               return ret;
 
        /* Digital Input subdevice */
        s = &dev->subdevices[2];