staging: comedi: ii_pci20kc: 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.

Remove the unused private data and its allocation.

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/ii_pci20kc.c b/drivers/staging/comedi/drivers/ii_pci20kc.c
index 10e8073..cc5fd75 100644 (file)
--- a/drivers/staging/comedi/drivers/ii_pci20kc.c
+++ b/drivers/staging/comedi/drivers/ii_pci20kc.c
@@ -132,46 +132,25 @@ static const struct comedi_lrange ii20k_ai_ranges = {
        },
 };
 
-struct ii20k_ao_private {
-       unsigned int last_data[2];
-};
-
 static void __iomem *ii20k_module_iobase(struct comedi_device *dev,
                                         struct comedi_subdevice *s)
 {
        return dev->mmio + (s->index + 1) * II20K_MOD_OFFSET;
 }
 
-static int ii20k_ao_insn_read(struct comedi_device *dev,
-                             struct comedi_subdevice *s,
-                             struct comedi_insn *insn,
-                             unsigned int *data)
-{
-       struct ii20k_ao_private *ao_spriv = s->private;
-       unsigned int chan = CR_CHAN(insn->chanspec);
-       int i;
-
-       for (i = 0; i < insn->n; i++)
-               data[i] = ao_spriv->last_data[chan];
-
-       return insn->n;
-}
-
 static int ii20k_ao_insn_write(struct comedi_device *dev,
                               struct comedi_subdevice *s,
                               struct comedi_insn *insn,
                               unsigned int *data)
 {
-       struct ii20k_ao_private *ao_spriv = s->private;
        void __iomem *iobase = ii20k_module_iobase(dev, s);
        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];
 
-               ao_spriv->last_data[chan] = val;
+               s->readback[chan] = val;
 
                /* munge data */
                val += ((s->maxdata + 1) >> 1);
@@ -398,26 +377,26 @@ static int ii20k_dio_insn_bits(struct comedi_device *dev,
 static int ii20k_init_module(struct comedi_device *dev,
                             struct comedi_subdevice *s)
 {
-       struct ii20k_ao_private *ao_spriv;
        void __iomem *iobase = ii20k_module_iobase(dev, s);
        unsigned char id;
+       int ret;
 
        id = readb(iobase + II20K_ID_REG);
        switch (id) {
        case II20K_ID_PCI20006M_1:
        case II20K_ID_PCI20006M_2:
-               ao_spriv = comedi_alloc_spriv(s, sizeof(*ao_spriv));
-               if (!ao_spriv)
-                       return -ENOMEM;
-
                /* Analog Output subdevice */
                s->type         = COMEDI_SUBD_AO;
                s->subdev_flags = SDF_WRITABLE;
                s->n_chan       = (id == II20K_ID_PCI20006M_2) ? 2 : 1;
                s->maxdata      = 0xffff;
                s->range_table  = &ii20k_ao_ranges;
-               s->insn_read    = ii20k_ao_insn_read;
                s->insn_write   = ii20k_ao_insn_write;
+               s->insn_read    = comedi_readback_insn_read;
+
+               ret = comedi_alloc_subdev_readback(s);
+               if (ret)
+                       return ret;
                break;
        case II20K_ID_PCI20341M_1:
                /* Analog Input subdevice */