staging: comedi: das1800: tidy up das1800_ao_insn_write()

The (*insn_write) functions are supposed to write insn->n values to the
specified channel. Tidy up this function and make it work like the core
expects.

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/das1800.c b/drivers/staging/comedi/drivers/das1800.c
index 45d72013917cba781b57a94941aa5612b2f18699..962a414e0544a3b40db4a20fd8b1fa0253da6324 100644 (file)
--- a/drivers/staging/comedi/drivers/das1800.c
+++ b/drivers/staging/comedi/drivers/das1800.c
@@ -1086,30 +1086,36 @@ static int das1800_ao_insn_write(struct comedi_device *dev,
                                 struct comedi_insn *insn,
                                 unsigned int *data)
 {
-       const struct das1800_board *board = dev->board_ptr;
        struct das1800_private *devpriv = dev->private;
-       int chan = CR_CHAN(insn->chanspec);
-/* int range = CR_RANGE(insn->chanspec); */
-       int update_chan = board->ao_n_chan - 1;
-       unsigned short output;
-       unsigned long irq_flags;
+       unsigned int chan = CR_CHAN(insn->chanspec);
+       unsigned int update_chan = s->n_chan - 1;
+       unsigned long flags;
+       int i;
 
-       output = comedi_offset_munge(s, data[0]);
-       /*  if the write is to the 'update' channel, we need to remember its value */
-       if (chan == update_chan)
-               devpriv->ao_update_bits = output;
-       /*  write to channel */
-       spin_lock_irqsave(&dev->spinlock, irq_flags);
-       outb(DAC(chan), dev->iobase + DAS1800_SELECT);  /* select dac channel for baseAddress + 0x0 */
-       outw(output, dev->iobase + DAS1800_DAC);
-       /*  now we need to write to 'update' channel to update all dac channels */
-       if (chan != update_chan) {
-               outb(DAC(update_chan), dev->iobase + DAS1800_SELECT);   /* select 'update' channel for baseAddress + 0x0 */
-               outw(devpriv->ao_update_bits, dev->iobase + DAS1800_DAC);
+       /* protects the indirect addressing selected by DAS1800_SELECT */
+       spin_lock_irqsave(&dev->spinlock, flags);
+
+       for (i = 0; i < insn->n; i++) {
+               unsigned int val = data[i];
+
+               val = comedi_offset_munge(s, val);
+               if (chan == update_chan)
+                       devpriv->ao_update_bits = val;
+
+               /* load this channel (and update if it's the last channel) */
+               outb(DAC(chan), dev->iobase + DAS1800_SELECT);
+               outw(val, dev->iobase + DAS1800_DAC);
+
+               /* update all channels */
+               if (chan != update_chan) {
+                       outb(DAC(update_chan), dev->iobase + DAS1800_SELECT);
+                       outw(devpriv->ao_update_bits,
+                            dev->iobase + DAS1800_DAC);
+               }
        }
-       spin_unlock_irqrestore(&dev->spinlock, irq_flags);
+       spin_unlock_irqrestore(&dev->spinlock, flags);
 
-       return 1;
+       return insn->n;
 }
 
 static int das1800_di_insn_bits(struct comedi_device *dev,