staging: comedi: usbduxsigma: 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/usbduxsigma.c b/drivers/staging/comedi/drivers/usbduxsigma.c
index a418be0..fad099d 100644 (file)
--- a/drivers/staging/comedi/drivers/usbduxsigma.c
+++ b/drivers/staging/comedi/drivers/usbduxsigma.c
@@ -75,8 +75,6 @@
 /* Number of channels (16 AD and offset)*/
 #define NUMCHANNELS 16
 
-#define USBDUXSIGMA_NUM_AO_CHAN                4
-
 /* Size of one A/D value */
 #define SIZEADIN          ((sizeof(uint32_t)))
 
@@ -161,8 +159,6 @@ struct usbduxsigma_private {
        /* input buffer for single insn */
        uint8_t *insn_buf;
 
-       unsigned int ao_readback[USBDUXSIGMA_NUM_AO_CHAN];
-
        unsigned high_speed:1;
        unsigned ai_cmd_running:1;
        unsigned ao_cmd_running:1;
@@ -428,7 +424,7 @@ static void usbduxsigma_ao_urb_complete(struct urb *urb)
                        }
                        *datap++ = val;
                        *datap++ = chan;
-                       devpriv->ao_readback[chan] = val;
+                       s->readback[chan] = val;
 
                        s->async->events |= COMEDI_CB_BLOCK;
                        comedi_event(dev, s);
@@ -806,15 +802,13 @@ static int usbduxsigma_ao_insn_read(struct comedi_device *dev,
                                    unsigned int *data)
 {
        struct usbduxsigma_private *devpriv = dev->private;
-       unsigned int chan = CR_CHAN(insn->chanspec);
-       int i;
+       int ret;
 
        down(&devpriv->sem);
-       for (i = 0; i < insn->n; i++)
-               data[i] = devpriv->ao_readback[chan];
+       ret = comedi_readback_insn_read(dev, s, insn, data);
        up(&devpriv->sem);
 
-       return insn->n;
+       return ret;
 }
 
 static int usbduxsigma_ao_insn_write(struct comedi_device *dev,
@@ -842,7 +836,7 @@ static int usbduxsigma_ao_insn_write(struct comedi_device *dev,
                        up(&devpriv->sem);
                        return ret;
                }
-               devpriv->ao_readback[chan] = data[i];
+               s->readback[chan] = data[i];
        }
        up(&devpriv->sem);
 
@@ -1611,7 +1605,7 @@ static int usbduxsigma_auto_attach(struct comedi_device *dev,
        dev->write_subdev = s;
        s->type         = COMEDI_SUBD_AO;
        s->subdev_flags = SDF_WRITABLE | SDF_GROUND | SDF_CMD_WRITE;
-       s->n_chan       = USBDUXSIGMA_NUM_AO_CHAN;
+       s->n_chan       = 4;
        s->len_chanlist = s->n_chan;
        s->maxdata      = 0x00ff;
        s->range_table  = &range_unipolar2_5;
@@ -1621,6 +1615,10 @@ static int usbduxsigma_auto_attach(struct comedi_device *dev,
        s->do_cmd       = usbduxsigma_ao_cmd;
        s->cancel       = usbduxsigma_ao_cancel;
 
+       ret = comedi_alloc_subdev_readback(s);
+       if (ret)
+               return ret;
+
        /* Digital I/O subdevice */
        s = &dev->subdevices[2];
        s->type         = COMEDI_SUBD_DIO;