staging: comedi: ni_660x: cleanup ni_660x_dio_insn_config()

This function handles all the insn_config instructions for the
digital i/o subdevice. These functions are supposed to return
the number of instruction parameters used (insn->n) or an -errno.
Fix the switch() so that the correct result is returned for all
INSN_CONFIG_* cases.

To clarify the code, add a local variable for the 'bit' used with
the instructions used to configure and query the input/output setting
of a channel.

For aesthetic reasons, add a whitespace between each case to improve
readability.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/drivers/ni_660x.c b/drivers/staging/comedi/drivers/ni_660x.c
index 360d873e57ef6e884dd2c566f3ae63bd75b97352..318057546485af43bbdf1ea0fb5bddaa73037dac 100644 (file)
--- a/drivers/staging/comedi/drivers/ni_660x.c
+++ b/drivers/staging/comedi/drivers/ni_660x.c
@@ -1116,49 +1116,54 @@ static int ni_660x_set_pfi_routing(struct comedi_device *dev, unsigned chan,
 
 static int ni_660x_dio_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 ni_660x_private *devpriv = dev->private;
-       int chan = CR_CHAN(insn->chanspec);
+       unsigned int chan = CR_CHAN(insn->chanspec);
+       uint64_t bit = 1ULL << chan;
        unsigned int val;
-
-       /* The input or output configuration of each digital line is
-        * configured by a special insn_config instruction.  chanspec
-        * contains the channel to be changed, and data[0] contains the
-        * value COMEDI_INPUT or COMEDI_OUTPUT. */
+       int ret;
 
        switch (data[0]) {
        case INSN_CONFIG_DIO_OUTPUT:
-               devpriv->pfi_direction_bits |= ((uint64_t) 1) << chan;
+               devpriv->pfi_direction_bits |= bit;
                ni_660x_select_pfi_output(dev, chan,
                                          devpriv->pfi_output_selects[chan]);
                break;
+
        case INSN_CONFIG_DIO_INPUT:
-               devpriv->pfi_direction_bits &= ~(((uint64_t) 1) << chan);
+               devpriv->pfi_direction_bits &= ~bit;
                ni_660x_select_pfi_output(dev, chan, pfi_output_select_high_Z);
                break;
+
        case INSN_CONFIG_DIO_QUERY:
-               data[1] =
-                   (devpriv->pfi_direction_bits &
-                    (((uint64_t) 1) << chan)) ? COMEDI_OUTPUT : COMEDI_INPUT;
-               return 0;
+               data[1] = (devpriv->pfi_direction_bits & bit) ? COMEDI_OUTPUT
+                                                             : COMEDI_INPUT;
+               break;
+
        case INSN_CONFIG_SET_ROUTING:
-               return ni_660x_set_pfi_routing(dev, chan, data[1]);
+               ret = ni_660x_set_pfi_routing(dev, chan, data[1]);
+               if (ret)
+                       return ret;
                break;
+
        case INSN_CONFIG_GET_ROUTING:
                data[1] = devpriv->pfi_output_selects[chan];
                break;
+
        case INSN_CONFIG_FILTER:
                val = ni_660x_read_register(dev, 0, IOConfigReg(chan));
                val &= ~pfi_input_select_mask(chan);
                val |= pfi_input_select_bits(chan, data[1]);
                ni_660x_write_register(dev, 0, val, IOConfigReg(chan));
                break;
+
        default:
                return -EINVAL;
-               break;
        }
-       return 0;
+
+       return insn->n;
 }
 
 static int __devinit ni_660x_attach_pci(struct comedi_device *dev,