Commit 532a411e authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman

staging: comedi: cb_pcimdas: fix analog input channel configuration

The hardware uses a switch on the board to set the number of analog
input channels to either 16 single-ended or 8 differential channels.
Currently the switch setting is checked for every (*insn_read) operation
to validate the channel number.

Check the switch setting during the driver attach and initialize the
subdevice accordingly. This allows the core to handle the validation.
Signed-off-by: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent bca3a6d1
......@@ -109,20 +109,10 @@ static int cb_pcimdas_ai_rinsn(struct comedi_device *dev,
unsigned int d;
int chan = CR_CHAN(insn->chanspec);
unsigned short chanlims;
int maxchans;
int ret;
/* only support sw initiated reads from a single channel */
/* check channel number */
if ((inb(devpriv->BADR3 + 2) & 0x20) == 0) /* differential mode */
maxchans = s->n_chan / 2;
else
maxchans = s->n_chan;
if (chan > (maxchans - 1))
return -ETIMEDOUT; /* *** Wrong error code. Fixme. */
/* configure for sw initiated read */
d = inb(devpriv->BADR3 + 5);
if ((d & 0x03) > 0) { /* only reset if needed. */
......@@ -181,6 +171,20 @@ static int cb_pcimdas_ao_insn_write(struct comedi_device *dev,
return insn->n;
}
static bool cb_pcimdas_is_ai_se(struct comedi_device *dev)
{
struct cb_pcimdas_private *devpriv = dev->private;
unsigned int status;
/*
* The number of Analog Input channels is set with the
* Analog Input Mode Switch on the board. The board can
* have 16 single-ended or 8 differential channels.
*/
status = inb(devpriv->BADR3 + 2);
return status & 0x20;
}
static int cb_pcimdas_auto_attach(struct comedi_device *dev,
unsigned long context_unused)
{
......@@ -209,8 +213,14 @@ static int cb_pcimdas_auto_attach(struct comedi_device *dev,
/* dev->read_subdev=s; */
/* analog input subdevice */
s->type = COMEDI_SUBD_AI;
s->subdev_flags = SDF_READABLE | SDF_GROUND;
s->subdev_flags = SDF_READABLE;
if (cb_pcimdas_is_ai_se(dev)) {
s->subdev_flags |= SDF_GROUND;
s->n_chan = 16;
} else {
s->subdev_flags |= SDF_DIFF;
s->n_chan = 8;
}
s->maxdata = 0xffff;
s->range_table = &range_unknown;
s->len_chanlist = 1; /* This is the maximum chanlist length that */
......
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