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authorLinus Walleij <linus.walleij@linaro.org>2023-09-02 22:46:20 +0300
committerJonathan Cameron <Jonathan.Cameron@huawei.com>2023-10-17 22:25:32 +0300
commitbee448390e5166d019e9e037194d487ee94399d9 (patch)
tree6b9fcdef57d782ec83797f40f87f4c082cb7ea42 /drivers/iio
parent865b080e3229102f160889328ce2e8e97aa65ea0 (diff)
downloadlinux-bee448390e5166d019e9e037194d487ee94399d9.tar.xz
iio: afe: rescale: Accept only offset channels
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-AHGxKnxMeHD2s4Y4PuC29gBq6g@mail.gmail.com/ 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@linaro.org Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/iio')
-rw-r--r--drivers/iio/afe/iio-rescale.c19
1 files changed, 15 insertions, 4 deletions
diff --git a/drivers/iio/afe/iio-rescale.c b/drivers/iio/afe/iio-rescale.c
index 1f280c360701..56e5913ab82d 100644
--- a/drivers/iio/afe/iio-rescale.c
+++ b/drivers/iio/afe/iio-rescale.c
@@ -214,8 +214,18 @@ 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;
@@ -280,8 +290,9 @@ 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;