diff mbox series

[v2,1/9] iio: accel: bmc150: Fix bma222 scale unit

Message ID 20210610122126.50504-2-stephan@gerhold.net (mailing list archive)
State Superseded, archived
Headers show
Series iio: accel: bmc150: Add support for BMA253/BMA254 | expand

Commit Message

Stephan Gerhold June 10, 2021, 12:21 p.m. UTC
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@linaro.org>
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
---
Added this patch in v2 to avoid conflicts later in case this
should be backported to a stable kernel.
---
 drivers/iio/accel/bmc150-accel-core.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)
diff mbox series

Patch

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",