iio: imu: fxos8700: fix incorrect ODR mode readback

The absence of a correct offset leads an incorrect ODR mode
readback after use a hexadecimal number to mark the value from
FXOS8700_CTRL_REG1.

Get ODR mode by field mask and FIELD_GET clearly and conveniently.
And attach other additional fix for keeping the original code logic
and a good readability.

Fixes: 84e5ddd5 ("iio: imu: Add support for the FXOS8700 IMU")
Signed-off-by: Carlos Song <carlos.song@nxp.com>
Link: https://lore.kernel.org/r/20230118074227.1665098-2-carlos.song@nxp.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/fxos8700_core.c

@@ -10,6 +10,7 @@
 #include <linux/regmap.h>
 #include <linux/acpi.h>
 #include <linux/bitops.h>
+#include <linux/bitfield.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
@@ -144,9 +145,9 @@
 #define FXOS8700_NVM_DATA_BNK0      0xa7
 
 /* Bit definitions for FXOS8700_CTRL_REG1 */
-#define FXOS8700_CTRL_ODR_MSK       0x38
 #define FXOS8700_CTRL_ODR_MAX       0x00
 #define FXOS8700_CTRL_ODR_MIN       GENMASK(4, 3)
+#define FXOS8700_CTRL_ODR_MSK       GENMASK(5, 3)
 
 /* Bit definitions for FXOS8700_M_CTRL_REG1 */
 #define FXOS8700_HMS_MASK           GENMASK(1, 0)
@@ -508,10 +509,9 @@ static int fxos8700_set_odr(struct fxos8700_data *data, enum fxos8700_sensor t,
 	if (i >= odr_num)
 		return -EINVAL;
 
-	return regmap_update_bits(data->regmap,
-				  FXOS8700_CTRL_REG1,
-				  FXOS8700_CTRL_ODR_MSK + FXOS8700_ACTIVE,
-				  fxos8700_odr[i].bits << 3 | active_mode);
+	val &= ~FXOS8700_CTRL_ODR_MSK;
+	val |= FIELD_PREP(FXOS8700_CTRL_ODR_MSK, fxos8700_odr[i].bits) | FXOS8700_ACTIVE;
+	return regmap_write(data->regmap, FXOS8700_CTRL_REG1, val);
 }
 
 static int fxos8700_get_odr(struct fxos8700_data *data, enum fxos8700_sensor t,
@@ -524,7 +524,7 @@ static int fxos8700_get_odr(struct fxos8700_data *data, enum fxos8700_sensor t,
 	if (ret)
 		return ret;
 
-	val &= FXOS8700_CTRL_ODR_MSK;
+	val = FIELD_GET(FXOS8700_CTRL_ODR_MSK, val);
 
 	for (i = 0; i < odr_num; i++)
 		if (val == fxos8700_odr[i].bits)