diff options
| -rw-r--r-- | drivers/staging/comedi/drivers/comedi_test.c | 29 |
1 files changed, 23 insertions, 6 deletions
diff --git a/drivers/staging/comedi/drivers/comedi_test.c b/drivers/staging/comedi/drivers/comedi_test.c index 899faf71e014..53c9a5cb5a98 100644 --- a/drivers/staging/comedi/drivers/comedi_test.c +++ b/drivers/staging/comedi/drivers/comedi_test.c @@ -104,9 +104,17 @@ static unsigned short fake_sawtooth(struct comedi_device *dev, value = current_time; value *= binary_amplitude * 2; do_div(value, devpriv->usec_period); - value -= binary_amplitude; /* get rid of sawtooth's dc offset */ + value += offset; + /* get rid of sawtooth's dc offset and clamp value */ + if (value < binary_amplitude) { + value = 0; /* negative saturation */ + } else { + value -= binary_amplitude; + if (value > s->maxdata) + value = s->maxdata; /* positive saturation */ + } - return offset + value; + return value; } static unsigned short fake_squarewave(struct comedi_device *dev, @@ -119,16 +127,25 @@ static unsigned short fake_squarewave(struct comedi_device *dev, u64 value; const struct comedi_krange *krange = &s->range_table->range[range_index]; - current_time %= devpriv->usec_period; + current_time %= devpriv->usec_period; value = s->maxdata; value *= devpriv->uvolt_amplitude; do_div(value, krange->max - krange->min); - if (current_time < devpriv->usec_period / 2) - value *= -1; + /* get one of two values for square-wave and clamp */ + if (current_time < devpriv->usec_period / 2) { + if (offset < value) + value = 0; /* negative saturation */ + else + value = offset - value; + } else { + value += offset; + if (value > s->maxdata) + value = s->maxdata; /* positive saturation */ + } - return offset + value; + return value; } static unsigned short fake_flatline(struct comedi_device *dev, |