The coemdi (*insn_read) functions are supposed to read insn->n values
from the hardware. Make this function work like the core expects.
Use the comedi_offset_munge() helper to munge the two's complement
values to offset binary.
Signed-off-by: H Hartley Sweeten <hswee...@visionengravers.com>
Cc: Ian Abbott <abbo...@mev.co.uk>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
drivers/staging/comedi/drivers/me4000.c | 32 ++++++++++++++------------------
1 file changed, 14 insertions(+), 18 deletions(-)
diff --git a/drivers/staging/comedi/drivers/me4000.c
b/drivers/staging/comedi/drivers/me4000.c
index 4231e39..c15e731 100644
--- a/drivers/staging/comedi/drivers/me4000.c
+++ b/drivers/staging/comedi/drivers/me4000.c
@@ -456,16 +456,8 @@ static int me4000_ai_insn_read(struct comedi_device *dev,
int aref = CR_AREF(insn->chanspec);
unsigned int entry = 0;
unsigned int tmp;
- unsigned int lval;
int ret;
-
- if (insn->n == 0) {
- return 0;
- } else if (insn->n > 1) {
- dev_err(dev->class_dev, "Invalid instruction length %d\n",
- insn->n);
- return -EINVAL;
- }
+ int i;
entry |= ME4000_AI_LIST_RANGE(rang);
entry |= chan;
@@ -515,18 +507,22 @@ static int me4000_ai_insn_read(struct comedi_device *dev,
outl(ME4000_AI_MIN_TICKS, dev->iobase + ME4000_AI_CHAN_TIMER_REG);
outl(ME4000_AI_MIN_TICKS, dev->iobase + ME4000_AI_CHAN_PRE_TIMER_REG);
- /* Start conversion by dummy read */
- inl(dev->iobase + ME4000_AI_START_REG);
+ for (i = 0; i < insn->n; i++) {
+ unsigned int val;
- ret = comedi_timeout(dev, s, insn, me4000_ai_eoc, 0);
- if (ret)
- return ret;
+ /* start conversion by dummy read */
+ inl(dev->iobase + ME4000_AI_START_REG);
- /* Read value from data fifo */
- lval = inl(dev->iobase + ME4000_AI_DATA_REG) & 0xFFFF;
- data[0] = lval ^ 0x8000;
+ ret = comedi_timeout(dev, s, insn, me4000_ai_eoc, 0);
+ if (ret)
+ return ret;
- return 1;
+ /* read two's complement value and munge to offset binary */
+ val = inl(dev->iobase + ME4000_AI_DATA_REG);
+ data[i] = comedi_offset_munge(s, val);
+ }
+
+ return insn->n;
}
static int me4000_ai_cancel(struct comedi_device *dev,
--
2.4.3
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