diff options
| author | H Hartley Sweeten <hsweeten@visionengravers.com> | 2015-10-12 12:16:35 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-10-13 10:26:06 -0700 |
| commit | ee4c7709fbb29860c3200b1296a18adff01d2307 (patch) | |
| tree | f9ff0bcc637e3def4e6458a69f8103892c0133bc | |
| parent | 1198f6b09f05e1aef96e59c6af359dffa6d926e1 (diff) | |
staging: comedi: aio_aio12_8: fix ai (*insn_read)
According to the user manual, analog input bipolar data is 2's
complement and unipolar is straight binry. Use the core helpers
to munge the data appropriately.
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>
| -rw-r--r-- | drivers/staging/comedi/drivers/aio_aio12_8.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/staging/comedi/drivers/aio_aio12_8.c b/drivers/staging/comedi/drivers/aio_aio12_8.c index 2262da0d21b4..e76a1309a168 100644 --- a/drivers/staging/comedi/drivers/aio_aio12_8.c +++ b/drivers/staging/comedi/drivers/aio_aio12_8.c @@ -120,13 +120,15 @@ static int aio_aio12_8_ai_eoc(struct comedi_device *dev, static int aio_aio12_8_ai_read(struct comedi_device *dev, struct comedi_subdevice *s, - struct comedi_insn *insn, unsigned int *data) + struct comedi_insn *insn, + unsigned int *data) { unsigned int chan = CR_CHAN(insn->chanspec); unsigned int range = CR_RANGE(insn->chanspec); + unsigned int val; unsigned char control; int ret; - int n; + int i; /* * Setup the control byte for internal 2MHz clock, 3uS conversion, @@ -138,7 +140,7 @@ static int aio_aio12_8_ai_read(struct comedi_device *dev, /* Read status to clear EOC latch */ inb(dev->iobase + AIO12_8_STATUS_REG); - for (n = 0; n < insn->n; n++) { + for (i = 0; i < insn->n; i++) { /* Setup and start conversion */ outb(control, dev->iobase + AIO12_8_ADC_REG); @@ -147,7 +149,13 @@ static int aio_aio12_8_ai_read(struct comedi_device *dev, if (ret) return ret; - data[n] = inw(dev->iobase + AIO12_8_ADC_REG) & s->maxdata; + val = inw(dev->iobase + AIO12_8_ADC_REG) & s->maxdata; + + /* munge bipolar 2's complement data to offset binary */ + if (comedi_range_is_bipolar(s, range)) + val = comedi_offset_munge(s, val); + + data[i] = val; } return insn->n; |