staging: comedi: ni_6527: tidy up ni6527_di_insn_config()

The core will validate the insn->n value based on the actual instruction
(data[0]) that is being handled. Remove the sanity check and change the
instruction handling into a switch. This follows the normal format for
(*insn_config) functions and make adding additional instructions easier.

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_6527.c b/drivers/staging/comedi/drivers/ni_6527.c
index dc22f9f45749eaddc19b69bce96965628be3925e..65a1ba96fbabc5966792b740f99f514e3ad17450 100644 (file)
--- a/drivers/staging/comedi/drivers/ni_6527.c
+++ b/drivers/staging/comedi/drivers/ni_6527.c
@@ -123,32 +123,36 @@ static void ni6527_set_filter_enable(struct comedi_device *dev,
 
 static int ni6527_di_insn_config(struct comedi_device *dev,
                                 struct comedi_subdevice *s,
-                                struct comedi_insn *insn, unsigned int *data)
+                                struct comedi_insn *insn,
+                                unsigned int *data)
 {
        struct ni6527_private *devpriv = dev->private;
-       int chan = CR_CHAN(insn->chanspec);
+       unsigned int chan = CR_CHAN(insn->chanspec);
        unsigned int interval;
 
-       if (insn->n != 2)
-               return -EINVAL;
-
-       if (data[0] != INSN_CONFIG_FILTER)
-               return -EINVAL;
-
-       if (data[1]) {
+       switch (data[0]) {
+       case INSN_CONFIG_FILTER:
+               /*
+                * The deglitch filter interval is specified in nanoseconds.
+                * The hardware supports intervals in 200ns increments. Round
+                * the user values up and return the actual interval.
+                */
                interval = (data[1] + 100) / 200;
                data[1] = interval * 200;
 
-               ni6527_set_filter_interval(dev, interval);
-
-               devpriv->filter_enable |= 1 << chan;
-       } else {
-               devpriv->filter_enable &= ~(1 << chan);
+               if (interval) {
+                       ni6527_set_filter_interval(dev, interval);
+                       devpriv->filter_enable |= 1 << chan;
+               } else {
+                       devpriv->filter_enable &= ~(1 << chan);
+               }
+               ni6527_set_filter_enable(dev, devpriv->filter_enable);
+               break;
+       default:
+               return -EINVAL;
        }
 
-       ni6527_set_filter_enable(dev, devpriv->filter_enable);
-
-       return 2;
+       return insn->n;
 }
 
 static int ni6527_di_insn_bits(struct comedi_device *dev,