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| author | Liam Beguin <liambeguin@gmail.com> | 2022-01-08 23:53:06 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-15 15:17:58 +0300 |
| commit | 468757502e2fb74672045c5f6230c9634f740cc6 (patch) | |
| tree | dc154a954fd1a6a53ba19946c46ce01eaceca27a /drivers | |
| parent | be2b89a909b307087938b3167cc267a0ce1087fb (diff) | |
| download | linux-468757502e2fb74672045c5f6230c9634f740cc6.tar.xz | |
iio: inkern: make a best effort on offset calculation
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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/iio/inkern.c | 32 |
1 files changed, 27 insertions, 5 deletions
diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c index ad6c581ab216..ca0fe902a7db 100644 --- a/drivers/iio/inkern.c +++ b/drivers/iio/inkern.c @@ -588,13 +588,35 @@ EXPORT_SYMBOL_GPL(iio_read_channel_average_raw); 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); |