iio: iio: Fix iio_channel_read return if channel havn't info

[ Upstream commit 65de7654d39c70c2b942f801cea01590cf7e3458 ]

When xilinx-xadc is used with hwmon driver to read voltage, offset used
for temperature is always applied whatever the channel.

iio_channel_read must return an error to avoid offset for channel
without IIO_CHAN_INFO_OFFSET property.

Signed-off-by: Fabien Proriol <fabien.proriol@jdsu.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index f0846108d0067b4a979f3c3b86624b6e211cfa76..d33590e89337e500569fac35e1341b0f695e5e7f 100644 (file)
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -426,6 +426,9 @@ static int iio_channel_read(struct iio_channel *chan, int *val, int *val2,
        if (val2 == NULL)
                val2 = &unused;
 
+       if(!iio_channel_has_info(chan->channel, info))
+               return -EINVAL;
+
        if (chan->indio_dev->info->read_raw_multi) {
                ret = chan->indio_dev->info->read_raw_multi(chan->indio_dev,
                                        chan->channel, INDIO_MAX_RAW_ELEMENTS,