This is a note to let you know that I've just added the patch titled iio: accel: bma400: Fix the scale min and max macro values to the 5.10-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-accel-bma400-fix-the-scale-min-and-max-macro-val.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 689632afbf04e0a6e4e753d4af824d50c75c263c Author: Jagath Jog J <jagathjog1996@xxxxxxxxx> Date: Thu May 5 19:00:12 2022 +0530 iio: accel: bma400: Fix the scale min and max macro values [ Upstream commit 747c7cf1592e226d40543231b26502b332d0ea2f ] Changing the scale macro values to match the bma400 sensitivity for 1 LSB of all the available ranges. Fixes: 465c811f1f20 ("iio: accel: Add driver for the BMA400") Signed-off-by: Jagath Jog J <jagathjog1996@xxxxxxxxx> Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> Link: https://lore.kernel.org/r/20220505133021.22362-2-jagathjog1996@xxxxxxxxx Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/iio/accel/bma400.h b/drivers/iio/accel/bma400.h index 5ad10db9819f..416090c6b1e8 100644 --- a/drivers/iio/accel/bma400.h +++ b/drivers/iio/accel/bma400.h @@ -83,8 +83,27 @@ #define BMA400_ACC_ODR_MIN_WHOLE_HZ 25 #define BMA400_ACC_ODR_MIN_HZ 12 -#define BMA400_SCALE_MIN 38357 -#define BMA400_SCALE_MAX 306864 +/* + * BMA400_SCALE_MIN macro value represents m/s^2 for 1 LSB before + * converting to micro values for +-2g range. + * + * For +-2g - 1 LSB = 0.976562 milli g = 0.009576 m/s^2 + * For +-4g - 1 LSB = 1.953125 milli g = 0.019153 m/s^2 + * For +-16g - 1 LSB = 7.8125 milli g = 0.076614 m/s^2 + * + * The raw value which is used to select the different ranges is determined + * by the first bit set position from the scale value, so BMA400_SCALE_MIN + * should be odd. + * + * Scale values for +-2g, +-4g, +-8g and +-16g are populated into bma400_scales + * array by left shifting BMA400_SCALE_MIN. + * e.g.: + * To select +-2g = 9577 << 0 = raw value to write is 0. + * To select +-8g = 9577 << 2 = raw value to write is 2. + * To select +-16g = 9577 << 3 = raw value to write is 3. + */ +#define BMA400_SCALE_MIN 9577 +#define BMA400_SCALE_MAX 76617 #define BMA400_NUM_REGULATORS 2 #define BMA400_VDD_REGULATOR 0