staging: comedi: skel: use comedi_dio_update_state()

Convert this driver to use the comedi_dio_update_state() helper
function.

Tidy up the comments to reflect the new code.

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/skel.c b/drivers/staging/comedi/drivers/skel.c
index 9e964950a560ed92d9f37599d6138fd9c1a360b6..daee2f42bde0632c2cd05a38640ba1346a7bfeb6 100644 (file)
--- a/drivers/staging/comedi/drivers/skel.c
+++ b/drivers/staging/comedi/drivers/skel.c
@@ -332,30 +332,44 @@ static int skel_ao_rinsn(struct comedi_device *dev, struct comedi_subdevice *s,
        return i;
 }
 
-/* DIO devices are slightly special.  Although it is possible to
+/*
+ * DIO devices are slightly special. Although it is possible to
  * implement the insn_read/insn_write interface, it is much more
  * useful to applications if you implement the insn_bits interface.
- * This allows packed reading/writing of the DIO channels.  The
- * comedi core can convert between insn_bits and insn_read/write */
+ * This allows packed reading/writing of the DIO channels. The
+ * comedi core can convert between insn_bits and insn_read/write.
+ */
 static int skel_dio_insn_bits(struct comedi_device *dev,
                              struct comedi_subdevice *s,
-                             struct comedi_insn *insn, unsigned int *data)
+                             struct comedi_insn *insn,
+                             unsigned int *data)
 {
-       /* The insn data is a mask in data[0] and the new data
-        * in data[1], each channel cooresponding to a bit. */
-       if (data[0]) {
-               s->state &= ~data[0];
-               s->state |= data[0] & data[1];
+       /*
+        * The insn data is a mask in data[0] and the new data
+        * in data[1], each channel cooresponding to a bit.
+        *
+        * The core provided comedi_dio_update_state() function can
+        * be used to handle the internal state update to DIO subdevices
+        * with <= 32 channels. This function will return '0' if the
+        * state does not change or the mask of the channels that need
+        * to be updated.
+        */
+       if (comedi_dio_update_state(s, data)) {
                /* Write out the new digital output lines */
-               /* outw(s->state,dev->iobase + SKEL_DIO); */
+               /* outw(s->state, dev->iobase + SKEL_DIO); */
        }
 
-       /* on return, data[1] contains the value of the digital
-        * input and output lines. */
-       /* data[1]=inw(dev->iobase + SKEL_DIO); */
-       /* or we could just return the software copy of the output values if
-        * it was a purely digital output subdevice */
-       /* data[1]=s->state; */
+       /*
+        * On return, data[1] contains the value of the digital
+        * input and output lines.
+        */
+       /* data[1] = inw(dev->iobase + SKEL_DIO); */
+
+       /*
+        * Or we could just return the software copy of the output
+        * values if it was a purely digital output subdevice.
+        */
+       /* data[1] = s->state; */
 
        return insn->n;
 }