staging: comedi: dmm32at: tidy up dmm32at_ai_rinsn()

For aesthetics, rename this function to dmm32at_ai_insn_read().

Get the 'chan' and 'range' from the chanspec when declaring the local
variables. Remove the unecessary masking of the 'chan'.

Remove some unnecessary comments.

Change the final return to 'insn->n' to clarify the return value.

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/dmm32at.c b/drivers/staging/comedi/drivers/dmm32at.c
index b90f61965396adde7ccbc745ea60be8783839ec1..b21d08df4555306611b66388b7702525d9c62518 100644 (file)
--- a/drivers/staging/comedi/drivers/dmm32at.c
+++ b/drivers/staging/comedi/drivers/dmm32at.c
@@ -181,27 +181,22 @@ static int dmm32at_ai_status(struct comedi_device *dev,
        return -EBUSY;
 }
 
-static int dmm32at_ai_rinsn(struct comedi_device *dev,
-                           struct comedi_subdevice *s,
-                           struct comedi_insn *insn, unsigned int *data)
+static int dmm32at_ai_insn_read(struct comedi_device *dev,
+                               struct comedi_subdevice *s,
+                               struct comedi_insn *insn,
+                               unsigned int *data)
 {
-       int n;
-       unsigned char chan;
-       int range;
+       unsigned int chan = CR_CHAN(insn->chanspec);
+       unsigned int range = CR_RANGE(insn->chanspec);
        int ret;
-
-       /* get the channel and range number */
-
-       chan = CR_CHAN(insn->chanspec) & (s->n_chan - 1);
-       range = CR_RANGE(insn->chanspec);
+       int i;
 
        /* zero scan and fifo control and reset fifo */
        outb(DMM32AT_FIFORESET, dev->iobase + DMM32AT_FIFOCNTRL);
 
-       /* write the ai channel range regs */
+       /* set the channel and range */
        outb(chan, dev->iobase + DMM32AT_AILOW);
        outb(chan, dev->iobase + DMM32AT_AIHIGH);
-       /* set the range bits */
        outb(dmm32at_rangebits[range], dev->iobase + DMM32AT_AICONF);
 
        /* wait for circuit to settle */
@@ -209,22 +204,18 @@ static int dmm32at_ai_rinsn(struct comedi_device *dev,
        if (ret)
                return ret;
 
-       /* convert n samples */
-       for (n = 0; n < insn->n; n++) {
-               /* trigger conversion */
+       for (i = 0; i < insn->n; i++) {
                outb(0xff, dev->iobase + DMM32AT_CONV);
 
-               /* wait for conversion to end */
                ret = comedi_timeout(dev, s, insn, dmm32at_ai_status,
                                     DMM32AT_AISTAT);
                if (ret)
                        return ret;
 
-               data[n] = dmm32at_ai_get_sample(dev, s);
+               data[i] = dmm32at_ai_get_sample(dev, s);
        }
 
-       /* return the number of samples read/written */
-       return n;
+       return insn->n;
 }
 
 static int dmm32at_ns_to_timer(unsigned int *ns, unsigned int flags)
@@ -693,7 +684,7 @@ static int dmm32at_attach(struct comedi_device *dev,
        s->n_chan = 32;
        s->maxdata = 0xffff;
        s->range_table = &dmm32at_airanges;
-       s->insn_read = dmm32at_ai_rinsn;
+       s->insn_read = dmm32at_ai_insn_read;
        if (dev->irq) {
                dev->read_subdev = s;
                s->subdev_flags |= SDF_CMD_READ;