5.15-stable review patch. If anyone has any objections, please let me know.
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From: Linus Walleij linus.walleij@linaro.org
[ Upstream commit bee448390e5166d019e9e037194d487ee94399d9 ]
As noted by Jonathan Cameron: it is perfectly legal for a channel to have an offset but no scale in addition to the raw interface. The conversion will imply that scale is 1:1.
Make rescale_configure_channel() accept just scale, or just offset to process a channel.
When a user asks for IIO_CHAN_INFO_OFFSET in rescale_read_raw() we now have to deal with the fact that OFFSET could be present but SCALE missing. Add code to simply scale 1:1 in this case.
Link: https://lore.kernel.org/linux-iio/CACRpkdZXBjHU4t-GVOCFxRO-AHGxKnxMeHD2s4Y4P... Fixes: 53ebee949980 ("iio: afe: iio-rescale: Support processed channels") Fixes: 9decacd8b3a4 ("iio: afe: rescale: Fix boolean logic bug") Reported-by: Jonathan Cameron jic23@kernel.org Signed-off-by: Linus Walleij linus.walleij@linaro.org Reviewed-by: Peter Rosin peda@axentia.se Link: https://lore.kernel.org/r/20230902-iio-rescale-only-offset-v2-1-988b807754c8... Cc: Stable@vger.kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iio/afe/iio-rescale.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/drivers/iio/afe/iio-rescale.c b/drivers/iio/afe/iio-rescale.c index 84f21dc94a2f7..ea0a39882eb25 100644 --- a/drivers/iio/afe/iio-rescale.c +++ b/drivers/iio/afe/iio-rescale.c @@ -152,8 +152,18 @@ static int rescale_read_raw(struct iio_dev *indio_dev, return ret < 0 ? ret : -EOPNOTSUPP; }
- ret = iio_read_channel_scale(rescale->source, &scale, &scale2); - return rescale_process_offset(rescale, ret, scale, scale2, + if (iio_channel_has_info(rescale->source->channel, + IIO_CHAN_INFO_SCALE)) { + ret = iio_read_channel_scale(rescale->source, &scale, &scale2); + return rescale_process_offset(rescale, ret, scale, scale2, + schan_off, val, val2); + } + + /* + * If we get here we have no scale so scale 1:1 but apply + * rescaler and offset, if any. + */ + return rescale_process_offset(rescale, IIO_VAL_FRACTIONAL, 1, 1, schan_off, val, val2); default: return -EINVAL; @@ -218,8 +228,9 @@ static int rescale_configure_channel(struct device *dev, chan->type = rescale->cfg->type;
if (iio_channel_has_info(schan, IIO_CHAN_INFO_RAW) && - iio_channel_has_info(schan, IIO_CHAN_INFO_SCALE)) { - dev_info(dev, "using raw+scale source channel\n"); + (iio_channel_has_info(schan, IIO_CHAN_INFO_SCALE) || + iio_channel_has_info(schan, IIO_CHAN_INFO_OFFSET))) { + dev_info(dev, "using raw+scale/offset source channel\n"); } else if (iio_channel_has_info(schan, IIO_CHAN_INFO_PROCESSED)) { dev_info(dev, "using processed channel\n"); rescale->chan_processed = true;