staging: comedi: pcmmio: 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/pcmmio.c b/drivers/staging/comedi/drivers/pcmmio.c
index fed7e77..2c9a842 100644 (file)
--- a/drivers/staging/comedi/drivers/pcmmio.c
+++ b/drivers/staging/comedi/drivers/pcmmio.c
@@ -192,8 +192,6 @@ struct pcmmio_private {
        unsigned int enabled_mask;
        unsigned int stop_count;
        unsigned int active:1;
-
-       unsigned int ao_readback[8];
 };
 
 static void pcmmio_dio_write(struct comedi_device *dev, unsigned int val,
@@ -655,21 +653,6 @@ static int pcmmio_ai_insn_read(struct comedi_device *dev,
        return insn->n;
 }
 
-static int pcmmio_ao_insn_read(struct comedi_device *dev,
-                              struct comedi_subdevice *s,
-                              struct comedi_insn *insn,
-                              unsigned int *data)
-{
-       struct pcmmio_private *devpriv = dev->private;
-       unsigned int chan = CR_CHAN(insn->chanspec);
-       int i;
-
-       for (i = 0; i < insn->n; i++)
-               data[i] = devpriv->ao_readback[chan];
-
-       return insn->n;
-}
-
 static int pcmmio_ao_eoc(struct comedi_device *dev,
                         struct comedi_subdevice *s,
                         struct comedi_insn *insn,
@@ -688,11 +671,9 @@ static int pcmmio_ao_insn_write(struct comedi_device *dev,
                                struct comedi_insn *insn,
                                unsigned int *data)
 {
-       struct pcmmio_private *devpriv = dev->private;
        unsigned long iobase = dev->iobase;
        unsigned int chan = CR_CHAN(insn->chanspec);
        unsigned int range = CR_RANGE(insn->chanspec);
-       unsigned int val = devpriv->ao_readback[chan];
        unsigned char cmd = 0;
        int ret;
        int i;
@@ -719,7 +700,7 @@ static int pcmmio_ao_insn_write(struct comedi_device *dev,
                return ret;
 
        for (i = 0; i < insn->n; i++) {
-               val = data[i];
+               unsigned int val = data[i];
 
                /* write the data to the channel */
                outb(val & 0xff, iobase + PCMMIO_AO_LSB_REG);
@@ -731,7 +712,7 @@ static int pcmmio_ao_insn_write(struct comedi_device *dev,
                if (ret)
                        return ret;
 
-               devpriv->ao_readback[chan] = val;
+               s->readback[chan] = val;
        }
 
        return insn->n;
@@ -796,8 +777,12 @@ static int pcmmio_attach(struct comedi_device *dev, struct comedi_devconfig *it)
        s->n_chan       = 8;
        s->maxdata      = 0xffff;
        s->range_table  = &pcmmio_ao_ranges;
-       s->insn_read    = pcmmio_ao_insn_read;
        s->insn_write   = pcmmio_ao_insn_write;
+       s->insn_read    = comedi_readback_insn_read;
+
+       ret = comedi_alloc_subdev_readback(s);
+       if (ret)
+               return ret;
 
        /* initialize the resource enable register by clearing it */
        outb(0, dev->iobase + PCMMIO_AO_RESOURCE_ENA_REG);