This is a note to let you know that I've just added the patch titled iio: imu: st_lsm6dsx: discard samples during filters settling time to the 6.3-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-imu-st_lsm6dsx-discard-samples-during-filters-se.patch and it can be found in the queue-6.3 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit b36f36cf156110ed32141d90fe69c46dcfe127f0 Author: Lorenzo Bianconi <lorenzo@xxxxxxxxxx> Date: Mon Feb 27 12:14:56 2023 +0100 iio: imu: st_lsm6dsx: discard samples during filters settling time [ Upstream commit db3c490503bee4d0611f9fc17fcd8cfe6fcdbcad ] During digital filters settling time the driver is expected to drop samples since they can be corrupted. Introduce the capability to drop a given number of samples according to the configured ODR. Add sample_to_discard for LSM6DSM-like sensors since new generation devices (e.g. LSM6DSO) support DRDY mask where corrupted samples are masked in hw with values greather than 0x7ffd so the driver can easily discard them. I have not added sample_to_discard support for LSM6DS3 or LSM6DS3H since I do not have any sample for testing at the moment. Reported-by: Philippe De Muyter <phdm@xxxxxxxxx> Tested-by: Philippe De Muyter <phdm@xxxxxxxxx> Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx> Link: https://lore.kernel.org/r/21dcd94935c147ef9b1da4984b3da6264ee9609e.1677496295.git.lorenzo@xxxxxxxxxx Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h index 499fcf8875b40..8e119d78730ba 100644 --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h @@ -137,6 +137,13 @@ struct st_lsm6dsx_odr_table_entry { int odr_len; }; +struct st_lsm6dsx_samples_to_discard { + struct { + u32 milli_hz; + u16 samples; + } val[ST_LSM6DSX_ODR_LIST_SIZE]; +}; + struct st_lsm6dsx_fs { u32 gain; u8 val; @@ -291,6 +298,7 @@ struct st_lsm6dsx_ext_dev_settings { * @irq_config: interrupts related registers. * @drdy_mask: register info for data-ready mask (addr + mask). * @odr_table: Hw sensors odr table (Hz + val). + * @samples_to_discard: Number of samples to discard for filters settling time. * @fs_table: Hw sensors gain table (gain + val). * @decimator: List of decimator register info (addr + mask). * @batch: List of FIFO batching register info (addr + mask). @@ -323,6 +331,7 @@ struct st_lsm6dsx_settings { } irq_config; struct st_lsm6dsx_reg drdy_mask; 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]; @@ -353,6 +362,7 @@ enum st_lsm6dsx_fifo_mode { * @hw: Pointer to instance of struct st_lsm6dsx_hw. * @gain: Configured sensor sensitivity. * @odr: Output data rate of the sensor [Hz]. + * @samples_to_discard: Number of samples to discard for filters settling time. * @watermark: Sensor watermark level. * @decimator: Sensor decimation factor. * @sip: Number of samples in a given pattern. @@ -367,6 +377,7 @@ struct st_lsm6dsx_sensor { u32 gain; u32 odr; + u16 samples_to_discard; u16 watermark; u8 decimator; u8 sip; diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c index 7dd5205aea5b4..f6c11d6fb0b0f 100644 --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c @@ -457,17 +457,31 @@ int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw) } if (gyro_sip > 0 && !(sip % gyro_sensor->decimator)) { - iio_push_to_buffers_with_timestamp( - hw->iio_devs[ST_LSM6DSX_ID_GYRO], - &hw->scan[ST_LSM6DSX_ID_GYRO], - gyro_sensor->ts_ref + ts); + /* + * We need to discards gyro samples during + * filters settling time + */ + if (gyro_sensor->samples_to_discard > 0) + gyro_sensor->samples_to_discard--; + else + iio_push_to_buffers_with_timestamp( + hw->iio_devs[ST_LSM6DSX_ID_GYRO], + &hw->scan[ST_LSM6DSX_ID_GYRO], + gyro_sensor->ts_ref + ts); gyro_sip--; } if (acc_sip > 0 && !(sip % acc_sensor->decimator)) { - iio_push_to_buffers_with_timestamp( - hw->iio_devs[ST_LSM6DSX_ID_ACC], - &hw->scan[ST_LSM6DSX_ID_ACC], - acc_sensor->ts_ref + ts); + /* + * We need to discards accel samples during + * filters settling time + */ + if (acc_sensor->samples_to_discard > 0) + acc_sensor->samples_to_discard--; + else + iio_push_to_buffers_with_timestamp( + hw->iio_devs[ST_LSM6DSX_ID_ACC], + &hw->scan[ST_LSM6DSX_ID_ACC], + acc_sensor->ts_ref + ts); acc_sip--; } if (ext_sip > 0 && !(sip % ext_sensor->decimator)) { @@ -654,6 +668,30 @@ int st_lsm6dsx_flush_fifo(struct st_lsm6dsx_hw *hw) return err; } +static void +st_lsm6dsx_update_samples_to_discard(struct st_lsm6dsx_sensor *sensor) +{ + const struct st_lsm6dsx_samples_to_discard *data; + struct st_lsm6dsx_hw *hw = sensor->hw; + int i; + + if (sensor->id != ST_LSM6DSX_ID_GYRO && + sensor->id != ST_LSM6DSX_ID_ACC) + return; + + /* check if drdy mask is supported in hw */ + if (hw->settings->drdy_mask.addr) + return; + + data = &hw->settings->samples_to_discard[sensor->id]; + for (i = 0; i < ST_LSM6DSX_ODR_LIST_SIZE; i++) { + if (data->val[i].milli_hz == sensor->odr) { + sensor->samples_to_discard = data->val[i].samples; + return; + } + } +} + int st_lsm6dsx_update_fifo(struct st_lsm6dsx_sensor *sensor, bool enable) { struct st_lsm6dsx_hw *hw = sensor->hw; @@ -673,6 +711,9 @@ int st_lsm6dsx_update_fifo(struct st_lsm6dsx_sensor *sensor, bool enable) goto out; } + if (enable) + st_lsm6dsx_update_samples_to_discard(sensor); + err = st_lsm6dsx_device_set_enable(sensor, enable); if (err < 0) goto out; diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c index 3f6060c64f32b..966df6ffe8740 100644 --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c @@ -634,6 +634,24 @@ static const struct st_lsm6dsx_settings st_lsm6dsx_sensor_settings[] = { .fs_len = 4, }, }, + .samples_to_discard = { + [ST_LSM6DSX_ID_ACC] = { + .val[0] = { 12500, 1 }, + .val[1] = { 26000, 1 }, + .val[2] = { 52000, 1 }, + .val[3] = { 104000, 2 }, + .val[4] = { 208000, 2 }, + .val[5] = { 416000, 2 }, + }, + [ST_LSM6DSX_ID_GYRO] = { + .val[0] = { 12500, 2 }, + .val[1] = { 26000, 5 }, + .val[2] = { 52000, 7 }, + .val[3] = { 104000, 12 }, + .val[4] = { 208000, 20 }, + .val[5] = { 416000, 36 }, + }, + }, .irq_config = { .irq1 = { .addr = 0x0d,