staging: comedi: s526: 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 and tidy it up a bit.

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/s526.c b/drivers/staging/comedi/drivers/s526.c
index 83f7433c2452ac2019675dbc5a812dc09f8ec7f6..75872c6aec2a1975be60f2d6da024ac84d323053 100644 (file)
--- a/drivers/staging/comedi/drivers/s526.c
+++ b/drivers/staging/comedi/drivers/s526.c
@@ -111,7 +111,6 @@ union cmReg {
 };
 
 struct s526_private {
-       unsigned int ao_readback[2];
        unsigned int gpct_config[4];
        unsigned short ai_config;
 };
@@ -467,38 +466,26 @@ static int s526_ai_rinsn(struct comedi_device *dev, struct comedi_subdevice *s,
        return n;
 }
 
-static int s526_ao_winsn(struct comedi_device *dev, struct comedi_subdevice *s,
-                        struct comedi_insn *insn, unsigned int *data)
+static int s526_ao_insn_write(struct comedi_device *dev,
+                             struct comedi_subdevice *s,
+                             struct comedi_insn *insn,
+                             unsigned int *data)
 {
-       struct s526_private *devpriv = dev->private;
        unsigned int chan = CR_CHAN(insn->chanspec);
-       unsigned short val;
+       unsigned int val = s->readback[chan];
        int i;
 
-       val = chan << 1;
-       outw(val, dev->iobase + REG_DAC);
+       outw(chan << 1, dev->iobase + REG_DAC);
 
        for (i = 0; i < insn->n; i++) {
-               outw(data[i], dev->iobase + REG_ADD);
-               devpriv->ao_readback[chan] = data[i];
+               val = data[i];
+               outw(val, dev->iobase + REG_ADD);
                /* starts the D/A conversion */
-               outw(val + 1, dev->iobase + REG_DAC);
+               outw((chan << 1) | 1, dev->iobase + REG_DAC);
        }
+       s->readback[chan] = val;
 
-       return i;
-}
-
-static int s526_ao_rinsn(struct comedi_device *dev, struct comedi_subdevice *s,
-                        struct comedi_insn *insn, unsigned int *data)
-{
-       struct s526_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 i;
+       return insn->n;
 }
 
 static int s526_dio_insn_bits(struct comedi_device *dev,
@@ -595,8 +582,12 @@ static int s526_attach(struct comedi_device *dev, struct comedi_devconfig *it)
        s->n_chan = 4;
        s->maxdata = 0xffff;
        s->range_table = &range_bipolar10;
-       s->insn_write = s526_ao_winsn;
-       s->insn_read = s526_ao_rinsn;
+       s->insn_write = s526_ao_insn_write;
+       s->insn_read = comedi_readback_insn_read;
+
+       ret = comedi_alloc_subdev_readback(s);
+       if (ret)
+               return ret;
 
        s = &dev->subdevices[3];
        /* digital i/o subdevice */