staging: comedi: das16: 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/das16.c b/drivers/staging/comedi/drivers/das16.c
index a347bcd..a7b4981 100644 (file)
--- a/drivers/staging/comedi/drivers/das16.c
+++ b/drivers/staging/comedi/drivers/das16.c
@@ -927,11 +927,13 @@ static int das16_ao_insn_write(struct comedi_device *dev,
                               unsigned int *data)
 {
        unsigned int chan = CR_CHAN(insn->chanspec);
-       unsigned int val;
        int i;
 
        for (i = 0; i < insn->n; i++) {
-               val = data[i];
+               unsigned int val = data[i];
+
+               s->readback[chan] = val;
+
                val <<= 4;
 
                outb(val & 0xff, dev->iobase + DAS16_AO_LSB_REG(chan));
@@ -1163,6 +1165,11 @@ static int das16_attach(struct comedi_device *dev, struct comedi_devconfig *it)
                s->maxdata      = 0x0fff;
                s->range_table  = devpriv->user_ao_range_table;
                s->insn_write   = das16_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;
        }