From adc8ec5ff183d09ae7a9d2dd31125401d302ba63 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Wed, 11 Jan 2017 11:48:39 +0100 Subject: [PATCH] iio: inkern: pass through raw values if no scaling When a consumer calls iio_read_channel_processed() the IIO core tries to apply scaling to the value, but if the channel only supports reading raw values, we should return that raw value to the cosumer instead of an error. This is what userspace is expected to do with sensors only providing raw values so the kernel should do the same, so as to avoid adding scaling boilerplate to drivers for hardware that actually return processed values from raw reads. A sensor not providing a scale, but providing a _raw attribute could be valid if for example the scale is the default of 1, but an offset needs to be applied to convert to the _processed form. Signed-off-by: Linus Walleij Signed-off-by: Jonathan Cameron --- drivers/iio/inkern.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c index b0f4630a163f..7a13535dc3e9 100644 --- a/drivers/iio/inkern.c +++ b/drivers/iio/inkern.c @@ -601,8 +601,14 @@ static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan, scale_type = iio_channel_read(chan, &scale_val, &scale_val2, IIO_CHAN_INFO_SCALE); - if (scale_type < 0) - return scale_type; + if (scale_type < 0) { + /* + * Just pass raw values as processed if no scaling is + * available. + */ + *processed = raw; + return 0; + } switch (scale_type) { case IIO_VAL_INT: