This is a note to let you know that I've just added the patch titled
iio: accel: bmc150: Fix bma222 scale unit
to my staging git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
in the staging-testing branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will be merged to the staging-next branch sometime soon,
after it passes testing, and the merge window is open.
If you have any questions about this process, please let me know.
>From 6e2a90af0b8d757e850cc023d761ee9a9492e2fe Mon Sep 17 00:00:00 2001
From: Stephan Gerhold <stephan@xxxxxxxxxxx>
Date: Fri, 11 Jun 2021 10:08:54 +0200
Subject: iio: accel: bmc150: Fix bma222 scale unit
According to sysfs-bus-iio documentation the unit for accelerometer
values after applying scale/offset should be m/s^2, not g, which explains
why the scale values for the other variants in bmc150-accel do not match
exactly the values given in the datasheet.
To get the correct values, we need to multiply the BMA222 scale values
by g = 9.80665 m/s^2.
Fixes: a1a210bf29a1 ("iio: accel: bmc150-accel: Add support for BMA222")
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Stephan Gerhold <stephan@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210611080903.14384-2-stephan@xxxxxxxxxxx
Cc: <Stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
---
drivers/iio/accel/bmc150-accel-core.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/iio/accel/bmc150-accel-core.c b/drivers/iio/accel/bmc150-accel-core.c
index a3d08d713362..a80ee0fdabc5 100644
--- a/drivers/iio/accel/bmc150-accel-core.c
+++ b/drivers/iio/accel/bmc150-accel-core.c
@@ -1145,11 +1145,12 @@ static const struct bmc150_accel_chip_info bmc150_accel_chip_info_tbl[] = {
/*
* The datasheet page 17 says:
* 15.6, 31.3, 62.5 and 125 mg per LSB.
+ * IIO unit is m/s^2 so multiply by g = 9.80665 m/s^2.
*/
- .scale_table = { {156000, BMC150_ACCEL_DEF_RANGE_2G},
- {313000, BMC150_ACCEL_DEF_RANGE_4G},
- {625000, BMC150_ACCEL_DEF_RANGE_8G},
- {1250000, BMC150_ACCEL_DEF_RANGE_16G} },
+ .scale_table = { {152984, BMC150_ACCEL_DEF_RANGE_2G},
+ {306948, BMC150_ACCEL_DEF_RANGE_4G},
+ {612916, BMC150_ACCEL_DEF_RANGE_8G},
+ {1225831, BMC150_ACCEL_DEF_RANGE_16G} },
},
[bma222e] = {
.name = "BMA222E",
--
2.32.0
