staging: comedi: cb_pcidas64: 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.

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_pcidas64.c b/drivers/staging/comedi/drivers/cb_pcidas64.c
index 77b0284..62f309b 100644 (file)
--- a/drivers/staging/comedi/drivers/cb_pcidas64.c
+++ b/drivers/staging/comedi/drivers/cb_pcidas64.c
@@ -1089,8 +1089,6 @@ struct pcidas64_private {
        unsigned int ao_dma_index;
        /*  number of analog output samples remaining */
        unsigned long ao_count;
-       /*  remember what the analog outputs are set to, to allow readback */
-       unsigned int ao_value[2];
        unsigned int hw_revision;       /*  stc chip hardware revision number */
        /*  last bits sent to INTR_ENABLE_REG register */
        unsigned int intr_enable_bits;
@@ -3061,18 +3059,7 @@ static int ao_winsn(struct comedi_device *dev, struct comedi_subdevice *s,
        }
 
        /*  remember output value */
-       devpriv->ao_value[chan] = data[0];
-
-       return 1;
-}
-
-static int ao_readback_insn(struct comedi_device *dev,
-                           struct comedi_subdevice *s,
-                           struct comedi_insn *insn, unsigned int *data)
-{
-       struct pcidas64_private *devpriv = dev->private;
-
-       data[0] = devpriv->ao_value[CR_CHAN(insn->chanspec)];
+       s->readback[chan] = data[0];
 
        return 1;
 }
@@ -3788,8 +3775,13 @@ static int setup_subdevices(struct comedi_device *dev)
                s->n_chan = thisboard->ao_nchan;
                s->maxdata = (1 << thisboard->ao_bits) - 1;
                s->range_table = thisboard->ao_range_table;
-               s->insn_read = ao_readback_insn;
                s->insn_write = ao_winsn;
+               s->insn_read = comedi_readback_insn_read;
+
+               ret = comedi_alloc_subdev_readback(s);
+               if (ret)
+                       return ret;
+
                if (ao_cmd_is_supported(thisboard)) {
                        dev->write_subdev = s;
                        s->do_cmdtest = ao_cmdtest;