This is a note to let you know that I've just added the patch titled
iio: afe: rescale: Accept only offset channels
to the 6.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iio-afe-rescale-accept-only-offset-channels.patch
and it can be found in the queue-6.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From bee448390e5166d019e9e037194d487ee94399d9 Mon Sep 17 00:00:00 2001
From: Linus Walleij <linus.walleij@xxxxxxxxxx>
Date: Sat, 2 Sep 2023 21:46:20 +0200
Subject: iio: afe: rescale: Accept only offset channels
From: Linus Walleij <linus.walleij@xxxxxxxxxx>
commit bee448390e5166d019e9e037194d487ee94399d9 upstream.
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@xxxxxxxxxxxxxx/
Fixes: 53ebee949980 ("iio: afe: iio-rescale: Support processed channels")
Fixes: 9decacd8b3a4 ("iio: afe: rescale: Fix boolean logic bug")
Reported-by: Jonathan Cameron <jic23@xxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Reviewed-by: Peter Rosin <peda@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230902-iio-rescale-only-offset-v2-1-988b807754c8@xxxxxxxxxx
Cc: <Stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/iio/afe/iio-rescale.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)
--- 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_d
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(str
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;
Patches currently in stable-queue which might be from linus.walleij@xxxxxxxxxx are
queue-6.5/iio-afe-rescale-accept-only-offset-channels.patch
