iio: imu: fxos8700: fix MAGN sensor scale and unit

commit 2acd031347f645871959a799238a7caf6803aa18 upstream.

+/-1200uT is a MAGN sensor full measurement range. Magnetometer scale
is the magnetic sensitivity parameter. It is referenced as 0.1uT
according to datasheet and magnetometer channel unit is Gauss in
sysfs-bus-iio documentation. Gauss and uTesla unit conversion
relationship as follows: 0.1uT = 0.001Gs.

Set magnetometer scale and available magnetometer scale as fixed 0.001Gs.

Fixes: 2c7e7594a2fd ("iio: imu: Add support for the FXOS8700 IMU")
Signed-off-by: Carlos Song <carlos.song@nxp.com>
Link: https://lore.kernel.org/r/20230118074227.1665098-5-carlos.song@nxp.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/iio/imu/fxos8700_core.c b/drivers/iio/imu/fxos8700_core.c
index 880b9bcb80ff472920941eb37d328dc00d03b5c3..6d189c4b9ff962e0a241680e2d075a002ff69c39 100644 (file)
--- a/drivers/iio/imu/fxos8700_core.c
+++ b/drivers/iio/imu/fxos8700_core.c
@@ -351,7 +351,7 @@ static int fxos8700_set_scale(struct fxos8700_data *data,
        struct device *dev = regmap_get_device(data->regmap);
 
        if (t == FXOS8700_MAGN) {
-               dev_err(dev, "Magnetometer scale is locked at 1200uT\n");
+               dev_err(dev, "Magnetometer scale is locked at 0.001Gs\n");
                return -EINVAL;
        }
 
@@ -396,7 +396,7 @@ static int fxos8700_get_scale(struct fxos8700_data *data,
        static const int scale_num = ARRAY_SIZE(fxos8700_accel_scale);
 
        if (t == FXOS8700_MAGN) {
-               *uscale = 1200; /* Magnetometer is locked at 1200uT */
+               *uscale = 1000; /* Magnetometer is locked at 0.001Gs */
                return 0;
        }
 
@@ -588,7 +588,7 @@ static IIO_CONST_ATTR(in_accel_sampling_frequency_available,
 static IIO_CONST_ATTR(in_magn_sampling_frequency_available,
                      "1.5625 6.25 12.5 50 100 200 400 800");
 static IIO_CONST_ATTR(in_accel_scale_available, "0.000244 0.000488 0.000976");
-static IIO_CONST_ATTR(in_magn_scale_available, "0.000001200");
+static IIO_CONST_ATTR(in_magn_scale_available, "0.001000");
 
 static struct attribute *fxos8700_attrs[] = {
        &iio_const_attr_in_accel_sampling_frequency_available.dev_attr.attr,