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| author | Linus Walleij <linus.walleij@linaro.org> | 2021-03-08 11:02:18 +0100 |
|---|---|---|
| committer | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2021-03-25 19:13:51 +0000 |
| commit | 635ef601b2387c3215252c9931786524d122c0e7 (patch) | |
| tree | b60132242319a0e98ffafdeef59b4fadd28ecde2 /include/linux/iio | |
| parent | 86073fa2b538847f4a623c040f66d1ec96e0643a (diff) | |
| download | lwn-635ef601b2387c3215252c9931786524d122c0e7.tar.gz lwn-635ef601b2387c3215252c9931786524d122c0e7.zip | |
iio: Provide iio_read_channel_processed_scale() API
Since the old iio_read_channel_processed() would
lose precision if we fall back to reading raw and
scaling, we introduce a new API that will pass in
a scale factor when reading a processed channel:
iio_read_channel_processed_scale().
Refactor iio_read_channel_processed() as a special
case with scale factor 1.
Cc: Peter Rosin <peda@axentia.se>
Cc: Chris Lesiak <chris.lesiak@licor.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: linux-iio@vger.kernel.org
Link: https://lore.kernel.org/linux-iio/20201224011607.1059534-1-linus.walleij@linaro.org/
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210308100219.2732156-1-linus.walleij@linaro.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'include/linux/iio')
| -rw-r--r-- | include/linux/iio/consumer.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h index 0a90ba8fa1bb..5fa5957586cf 100644 --- a/include/linux/iio/consumer.h +++ b/include/linux/iio/consumer.h @@ -242,6 +242,21 @@ int iio_read_channel_average_raw(struct iio_channel *chan, int *val); int iio_read_channel_processed(struct iio_channel *chan, int *val); /** + * iio_read_channel_processed_scale() - read and scale a processed value + * @chan: The channel being queried. + * @val: Value read back. + * @scale: Scale factor to apply during the conversion + * + * Returns an error code or 0. + * + * This function will read a processed value from a channel. This will work + * like @iio_read_channel_processed() but also scale with an additional + * scale factor while attempting to minimize any precision loss. + */ +int iio_read_channel_processed_scale(struct iio_channel *chan, int *val, + unsigned int scale); + +/** * iio_write_channel_attribute() - Write values to the device attribute. * @chan: The channel being queried. * @val: Value being written. |