As every chip has some little variant in LPF bandwidth values,
use common values that are working for all chips.
Simplify the LPF setting function.
Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@xxxxxxxxxxxxxx>
---
drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 30 ++++++++++++----------
drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h | 10 ++++----
2 files changed, 21 insertions(+), 19 deletions(-)
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
index 9ecc667debbe..c4db9086775c 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
@@ -707,30 +707,32 @@ static int inv_mpu6050_write_raw(struct iio_dev *indio_dev,
/**
* inv_mpu6050_set_lpf() - set low pass filer based on fifo rate.
*
- * Based on the Nyquist principle, the sampling rate must
- * exceed twice of the bandwidth of the signal, or there
- * would be alising. This function basically search for the
- * correct low pass parameters based on the fifo rate, e.g,
- * sampling frequency.
+ * Based on the Nyquist principle, the bandwidth of the low
+ * pass filter must not exceed the signal sampling rate divided
+ * by 2, or there would be aliasing.
+ * This function basically search for the correct low pass
+ * parameters based on the fifo rate, e.g, sampling frequency.
*
* lpf is set automatically when setting sampling rate to avoid any aliases.
*/
static int inv_mpu6050_set_lpf(struct inv_mpu6050_state *st, int rate)
{
- static const int hz[] = {188, 98, 42, 20, 10, 5};
+ static const int hz[] = {400, 200, 90, 40, 20, 10};
static const int d[] = {
- INV_MPU6050_FILTER_188HZ, INV_MPU6050_FILTER_98HZ,
- INV_MPU6050_FILTER_42HZ, INV_MPU6050_FILTER_20HZ,
+ INV_MPU6050_FILTER_200HZ, INV_MPU6050_FILTER_100HZ,
+ INV_MPU6050_FILTER_45HZ, INV_MPU6050_FILTER_20HZ,
INV_MPU6050_FILTER_10HZ, INV_MPU6050_FILTER_5HZ
};
- int i, h, result;
+ int i, result;
u8 data;
- h = (rate >> 1);
- i = 0;
- while ((h < hz[i]) && (i < ARRAY_SIZE(d) - 1))
- i++;
- data = d[i];
+ data = INV_MPU6050_FILTER_5HZ;
+ for (i = 0; i < ARRAY_SIZE(hz); ++i) {
+ if (rate >= hz[i]) {
+ data = d[i];
+ break;
+ }
+ }
result = inv_mpu6050_set_lpf_regs(st, data);
if (result)
return result;
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
index 7ae614052210..9a81098a8b4d 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
@@ -370,14 +370,14 @@ enum inv_mpu6050_scan {
};
enum inv_mpu6050_filter_e {
- INV_MPU6050_FILTER_256HZ_NOLPF2 = 0,
- INV_MPU6050_FILTER_188HZ,
- INV_MPU6050_FILTER_98HZ,
- INV_MPU6050_FILTER_42HZ,
+ INV_MPU6050_FILTER_NOLPF2 = 0,
+ INV_MPU6050_FILTER_200HZ,
+ INV_MPU6050_FILTER_100HZ,
+ INV_MPU6050_FILTER_45HZ,
INV_MPU6050_FILTER_20HZ,
INV_MPU6050_FILTER_10HZ,
INV_MPU6050_FILTER_5HZ,
- INV_MPU6050_FILTER_2100HZ_NOLPF,
+ INV_MPU6050_FILTER_NOLPF,
NUM_MPU6050_FILTER
};
--
2.17.1
