From: Liam Beguin liambeguin@gmail.com
commit ca85123354e1a65a22170286387b4791997fe864 upstream.
iio_convert_raw_to_processed_unlocked() assumes the offset is an integer. Make a best effort to get a valid offset value for fractional cases without breaking implicit truncations.
Fixes: 48e44ce0f881 ("iio:inkern: Add function to read the processed value") Signed-off-by: Liam Beguin liambeguin@gmail.com Reviewed-by: Peter Rosin peda@axentia.se Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com Link: https://lore.kernel.org/r/20220108205319.2046348-4-liambeguin@gmail.com Cc: Stable@vger.kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iio/inkern.c | 32 +++++++++++++++++++++++++++----- 1 file changed, 27 insertions(+), 5 deletions(-)
--- a/drivers/iio/inkern.c +++ b/drivers/iio/inkern.c @@ -578,13 +578,35 @@ EXPORT_SYMBOL_GPL(iio_read_channel_avera static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan, int raw, int *processed, unsigned int scale) { - int scale_type, scale_val, scale_val2, offset; + int scale_type, scale_val, scale_val2; + int offset_type, offset_val, offset_val2; s64 raw64 = raw; - int ret;
- ret = iio_channel_read(chan, &offset, NULL, IIO_CHAN_INFO_OFFSET); - if (ret >= 0) - raw64 += offset; + offset_type = iio_channel_read(chan, &offset_val, &offset_val2, + IIO_CHAN_INFO_OFFSET); + if (offset_type >= 0) { + switch (offset_type) { + case IIO_VAL_INT: + break; + case IIO_VAL_INT_PLUS_MICRO: + case IIO_VAL_INT_PLUS_NANO: + /* + * Both IIO_VAL_INT_PLUS_MICRO and IIO_VAL_INT_PLUS_NANO + * implicitely truncate the offset to it's integer form. + */ + break; + case IIO_VAL_FRACTIONAL: + offset_val /= offset_val2; + break; + case IIO_VAL_FRACTIONAL_LOG2: + offset_val >>= offset_val2; + break; + default: + return -EINVAL; + } + + raw64 += offset_val; + }
scale_type = iio_channel_read(chan, &scale_val, &scale_val2, IIO_CHAN_INFO_SCALE);