staging: comedi: cb_das16_cs: use comedi_subdevice 'readback'

Use the new comedi_subdevice 'readback' member and the core provided
(*insn_read) for the readback of the analog output subdevice channels.

For aesthetics, rename the (*insn_write) function.

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/cb_das16_cs.c b/drivers/staging/comedi/drivers/cb_das16_cs.c
index 853733e..f88880a 100644 (file)
--- a/drivers/staging/comedi/drivers/cb_das16_cs.c
+++ b/drivers/staging/comedi/drivers/cb_das16_cs.c
@@ -79,7 +79,6 @@ static const struct das16cs_board das16cs_boards[] = {
 };
 
 struct das16cs_private {
-       unsigned int ao_readback[2];
        unsigned short status1;
        unsigned short status2;
 };
@@ -153,20 +152,20 @@ static int das16cs_ai_rinsn(struct comedi_device *dev,
        return i;
 }
 
-static int das16cs_ao_winsn(struct comedi_device *dev,
-                           struct comedi_subdevice *s,
-                           struct comedi_insn *insn, unsigned int *data)
+static int das16cs_ao_insn_write(struct comedi_device *dev,
+                                struct comedi_subdevice *s,
+                                struct comedi_insn *insn,
+                                unsigned int *data)
 {
        struct das16cs_private *devpriv = dev->private;
-       int i;
-       int chan = CR_CHAN(insn->chanspec);
+       unsigned int chan = CR_CHAN(insn->chanspec);
+       unsigned int val = s->readback[chan];
        unsigned short status1;
-       unsigned short d;
        int bit;
+       int i;
 
        for (i = 0; i < insn->n; i++) {
-               devpriv->ao_readback[chan] = data[i];
-               d = data[i];
+               val = data[i];
 
                outw(devpriv->status1, dev->iobase + DAS16CS_MISC1);
                udelay(1);
@@ -181,7 +180,7 @@ static int das16cs_ao_winsn(struct comedi_device *dev,
                udelay(1);
 
                for (bit = 15; bit >= 0; bit--) {
-                       int b = (d >> bit) & 0x1;
+                       int b = (val >> bit) & 0x1;
 
                        b <<= 1;
                        outw(status1 | b | 0x0000, dev->iobase + DAS16CS_MISC1);
@@ -195,22 +194,9 @@ static int das16cs_ao_winsn(struct comedi_device *dev,
                 */
                outw(status1 | 0x9, dev->iobase + DAS16CS_MISC1);
        }
+       s->readback[chan] = val;
 
-       return i;
-}
-
-static int das16cs_ao_rinsn(struct comedi_device *dev,
-                           struct comedi_subdevice *s,
-                           struct comedi_insn *insn, unsigned int *data)
-{
-       struct das16cs_private *devpriv = dev->private;
-       int i;
-       int chan = CR_CHAN(insn->chanspec);
-
-       for (i = 0; i < insn->n; i++)
-               data[i] = devpriv->ao_readback[chan];
-
-       return i;
+       return insn->n;
 }
 
 static int das16cs_dio_insn_bits(struct comedi_device *dev,
@@ -318,8 +304,12 @@ static int das16cs_auto_attach(struct comedi_device *dev,
                s->n_chan       = board->n_ao_chans;
                s->maxdata      = 0xffff;
                s->range_table  = &range_bipolar10;
-               s->insn_write   = &das16cs_ao_winsn;
-               s->insn_read    = &das16cs_ao_rinsn;
+               s->insn_write   = &das16cs_ao_insn_write;
+               s->insn_read    = comedi_readback_insn_read;
+
+               ret = comedi_alloc_subdev_readback(s);
+               if (ret)
+                       return ret;
        } else {
                s->type         = COMEDI_SUBD_UNUSED;
        }