Introduce a helper function to get a two's complement sample from
the FIFO and munge it to the offset binary format that comedi uses.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/quatech_daqp_cs.c | 23 ++++++++++++++++-------
1 file changed, 16 insertions(+), 7 deletions(-)
diff --git a/drivers/staging/comedi/drivers/quatech_daqp_cs.c b/drivers/staging/comedi/drivers/quatech_daqp_cs.c
index b2effb8..cf144ce 100644
--- a/drivers/staging/comedi/drivers/quatech_daqp_cs.c
+++ b/drivers/staging/comedi/drivers/quatech_daqp_cs.c
@@ -172,6 +172,20 @@ static int daqp_ai_cancel(struct comedi_device *dev, struct comedi_subdevice *s)
return 0;
}
+static unsigned int daqp_ai_get_sample(struct comedi_device *dev,
+ struct comedi_subdevice *s)
+{
+ unsigned int val;
+
+ /*
+ * Get a two's complement sample from the FIFO and
+ * return the munged offset binary value.
+ */
+ val = inb(dev->iobase + DAQP_FIFO);
+ val |= inb(dev->iobase + DAQP_FIFO) << 8;
+ return comedi_offset_munge(s, val);
+}
+
/* Interrupt handler
*
* Operates in one of two modes. If devpriv->interrupt_mode is
@@ -209,10 +223,7 @@ static enum irqreturn daqp_interrupt(int irq, void *dev_id)
break;
}
- data = inb(dev->iobase + DAQP_FIFO);
- data |= inb(dev->iobase + DAQP_FIFO) << 8;
- data ^= 0x8000;
-
+ data = daqp_ai_get_sample(dev, s);
comedi_buf_write_samples(s, &data, 1);
/* If there's a limit, decrement it
@@ -323,9 +334,7 @@ static int daqp_ai_insn_read(struct comedi_device *dev,
if (wait_for_completion_interruptible(&devpriv->eos))
return -EINTR;
- data[i] = inb(dev->iobase + DAQP_FIFO);
- data[i] |= inb(dev->iobase + DAQP_FIFO) << 8;
- data[i] ^= 0x8000;
+ data[i] = daqp_ai_get_sample(dev, s);
}
return insn->n;
--
2.5.1
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