Hi Jonathan,
Le sam. 15 févr. 2020 à 18:32, Jonathan Cameron <ji...@kernel.org> a
écrit :
On Mon, 10 Feb 2020 19:54:38 -0300
Paul Cercueil <p...@crapouillou.net> wrote:
Implement write_raw by converting the value if writing the scale, or
just calling the managed channel driver's write_raw otherwise.
Signed-off-by: Paul Cercueil <p...@crapouillou.net>
---
drivers/iio/afe/iio-rescale.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/drivers/iio/afe/iio-rescale.c
b/drivers/iio/afe/iio-rescale.c
index 95802d9ee25e..a48f6af9316d 100644
--- a/drivers/iio/afe/iio-rescale.c
+++ b/drivers/iio/afe/iio-rescale.c
@@ -35,6 +35,27 @@ struct rescale {
int *scale_data;
};
+static int rescale_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct rescale *rescale = iio_priv(indio_dev);
+ unsigned long long tmp;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ tmp = val * 1000000000LL;
+ do_div(tmp, rescale->numerator);
+ tmp *= rescale->denominator;
+ do_div(tmp, 1000000000LL);
+ return iio_write_channel_attribute(rescale->source, tmp, 0,
+ IIO_CHAN_INFO_SCALE);
Why is val2 always 0? Won't that only work if the backend device
has integer scales?
Sorry, somehow I didn't see your answer.
Indeed, this will only work if the backend device has integer scales,
but what should I do? Just pass 'val2' instead of 0? Will the value be
correct if I only apply the scale ratio to 'val'?
Cheers,
-Paul
+ default:
+ return iio_write_channel_attribute(rescale->source,
+ val, val2, mask);
+ }
+}
+
static int rescale_convert(struct rescale *rescale, int type,
const int val, const int val2,
int *val_out, int *val2_out)
@@ -110,6 +131,7 @@ static int rescale_read_avail(struct iio_dev
*indio_dev,
}
static const struct iio_info rescale_info = {
+ .write_raw = rescale_write_raw,
.read_raw = rescale_read_raw,
.read_avail = rescale_read_avail,
};
