[PATCH v4 03/10] iio: inkern: make a best effort on offset calculation
From: Liam Beguin <hidden>
Date: 2021-07-06 16:10:12
Also in:
linux-iio, lkml
Subsystem:
iio subsystem and drivers, the rest · Maintainers:
Jonathan Cameron, Linus Torvalds
From: Liam Beguin <redacted>
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 <redacted>
---
drivers/iio/inkern.c | 32 +++++++++++++++++++++++++++-----
1 file changed, 27 insertions(+), 5 deletions(-)
diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index b69027690ed5..5e74d8983874 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c@@ -578,13 +578,35 @@ 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 /= (1 << offset_val2); + break; + default: + return -EINVAL; + } + + raw64 += offset_val; + } scale_type = iio_channel_read(chan, &scale_val, &scale_val2, IIO_CHAN_INFO_SCALE);
--
2.30.1.489.g328c10930387