diff options
Diffstat (limited to 'drivers/iio/imu')
| -rw-r--r-- | drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h | 40 | ||||
| -rw-r--r-- | drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c | 19 |
2 files changed, 37 insertions, 22 deletions
diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h index c225b246c8a5..381b016fa524 100644 --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h @@ -192,6 +192,22 @@ struct st_lsm6dsx_fifo_ops { * @fifo_en: Hw timer FIFO enable register info (addr + mask). * @decimator: Hw timer FIFO decimator register info (addr + mask). * @freq_fine: Difference in % of ODR with respect to the typical. + * @ts_sensitivity: Nominal timestamp sensitivity. + * @ts_trim_coeff: Coefficient for calculating the calibrated timestamp gain. + * This coefficient comes into play when linearizing the formula + * used to calculate the calibrated timestamp (please see the + * relevant formula in the AN for the specific IMU). + * For example, in the case of LSM6DSO we have: + * + * 1 / (1 + x) ~= 1 - x (Taylor’s Series) + * ttrim[s] = 1 / (40000 * (1 + 0.0015 * val)) (from AN5192) + * ttrim[ns] ~= 25000 - 37.5 * val + * ttrim[ns] ~= 25000 - (37500 * val) / 1000 + * + * so, replacing ts_sensitivity = 25000 and + * ts_trim_coeff = 37500 + * + * ttrim[ns] ~= ts_sensitivity - (ts_trim_coeff * val) / 1000 */ struct st_lsm6dsx_hw_ts_settings { struct st_lsm6dsx_reg timer_en; @@ -199,6 +215,8 @@ struct st_lsm6dsx_hw_ts_settings { struct st_lsm6dsx_reg fifo_en; struct st_lsm6dsx_reg decimator; u8 freq_fine; + u16 ts_sensitivity; + u16 ts_trim_coeff; }; /** @@ -252,6 +270,15 @@ struct st_lsm6dsx_event_settings { u8 wakeup_src_x_mask; }; +enum st_lsm6dsx_sensor_id { + ST_LSM6DSX_ID_GYRO, + ST_LSM6DSX_ID_ACC, + ST_LSM6DSX_ID_EXT0, + ST_LSM6DSX_ID_EXT1, + ST_LSM6DSX_ID_EXT2, + ST_LSM6DSX_ID_MAX +}; + enum st_lsm6dsx_ext_sensor_id { ST_LSM6DSX_ID_MAGN, }; @@ -337,23 +364,14 @@ struct st_lsm6dsx_settings { struct st_lsm6dsx_odr_table_entry odr_table[2]; struct st_lsm6dsx_samples_to_discard samples_to_discard[2]; struct st_lsm6dsx_fs_table_entry fs_table[2]; - struct st_lsm6dsx_reg decimator[ST_LSM6DSX_MAX_ID]; - struct st_lsm6dsx_reg batch[ST_LSM6DSX_MAX_ID]; + struct st_lsm6dsx_reg decimator[ST_LSM6DSX_ID_MAX]; + struct st_lsm6dsx_reg batch[2]; struct st_lsm6dsx_fifo_ops fifo_ops; struct st_lsm6dsx_hw_ts_settings ts_settings; struct st_lsm6dsx_shub_settings shub_settings; struct st_lsm6dsx_event_settings event_settings; }; -enum st_lsm6dsx_sensor_id { - ST_LSM6DSX_ID_GYRO, - ST_LSM6DSX_ID_ACC, - ST_LSM6DSX_ID_EXT0, - ST_LSM6DSX_ID_EXT1, - ST_LSM6DSX_ID_EXT2, - ST_LSM6DSX_ID_MAX, -}; - enum st_lsm6dsx_fifo_mode { ST_LSM6DSX_FIFO_BYPASS = 0x0, ST_LSM6DSX_FIFO_CONT = 0x6, diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c index d8cb4b0218d5..a2daf0c14d96 100644 --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c @@ -94,8 +94,6 @@ #define ST_LSM6DSX_REG_WHOAMI_ADDR 0x0f -#define ST_LSM6DSX_TS_SENSITIVITY 25000UL /* 25us */ - static const struct iio_chan_spec st_lsm6dsx_acc_channels[] = { ST_LSM6DSX_CHANNEL_ACC(IIO_ACCEL, 0x28, IIO_MOD_X, 0), ST_LSM6DSX_CHANNEL_ACC(IIO_ACCEL, 0x2a, IIO_MOD_Y, 1), @@ -983,6 +981,8 @@ static const struct st_lsm6dsx_settings st_lsm6dsx_sensor_settings[] = { .mask = GENMASK(7, 6), }, .freq_fine = 0x63, + .ts_sensitivity = 25000, + .ts_trim_coeff = 37500, }, .shub_settings = { .page_mux = { @@ -1196,6 +1196,8 @@ static const struct st_lsm6dsx_settings st_lsm6dsx_sensor_settings[] = { .mask = GENMASK(7, 6), }, .freq_fine = 0x63, + .ts_sensitivity = 25000, + .ts_trim_coeff = 37500, }, .event_settings = { .enable_reg = { @@ -1371,6 +1373,8 @@ static const struct st_lsm6dsx_settings st_lsm6dsx_sensor_settings[] = { .mask = GENMASK(7, 6), }, .freq_fine = 0x4f, + .ts_sensitivity = 21701, + .ts_trim_coeff = 28212, }, .shub_settings = { .page_mux = { @@ -2248,20 +2252,13 @@ static int st_lsm6dsx_init_hw_timer(struct st_lsm6dsx_hw *hw) } /* calibrate timestamp sensitivity */ - hw->ts_gain = ST_LSM6DSX_TS_SENSITIVITY; + hw->ts_gain = ts_settings->ts_sensitivity; if (ts_settings->freq_fine) { err = regmap_read(hw->regmap, ts_settings->freq_fine, &val); if (err < 0) return err; - /* - * linearize the AN5192 formula: - * 1 / (1 + x) ~= 1 - x (Taylor’s Series) - * ttrim[s] = 1 / (40000 * (1 + 0.0015 * val)) - * ttrim[ns] ~= 25000 - 37.5 * val - * ttrim[ns] ~= 25000 - (37500 * val) / 1000 - */ - hw->ts_gain -= ((s8)val * 37500) / 1000; + hw->ts_gain -= ((s8)val * ts_settings->ts_trim_coeff) / 1000; } return 0; |