inv-icm42600-y += inv_icm42600_accel.o
inv-icm42600-y += inv_icm42600_temp.o
inv-icm42600-y += inv_icm42600_buffer.o
+inv-icm42600-y += inv_icm42600_timestamp.o
obj-$(CONFIG_INV_ICM42600_I2C) += inv-icm42600-i2c.o
inv-icm42600-i2c-y += inv_icm42600_i2c.o
* @indio_accel: accelerometer IIO device.
* @buffer: data transfer buffer aligned for DMA.
* @fifo: FIFO management structure.
+ * @timestamp: interrupt timestamps.
*/
struct inv_icm42600_state {
struct mutex lock;
struct iio_dev *indio_accel;
uint8_t buffer[2] ____cacheline_aligned;
struct inv_icm42600_fifo fifo;
+ struct {
+ int64_t gyro;
+ int64_t accel;
+ } timestamp;
};
/* Virtual register addresses: @bank on MSB (4 upper bits), @address on LSB */
#include "inv_icm42600.h"
#include "inv_icm42600_temp.h"
#include "inv_icm42600_buffer.h"
+#include "inv_icm42600_timestamp.h"
#define INV_ICM42600_ACCEL_CHAN(_modifier, _index, _ext_info) \
{ \
INV_ICM42600_ACCEL_SCAN_Y,
INV_ICM42600_ACCEL_SCAN_Z,
INV_ICM42600_ACCEL_SCAN_TEMP,
+ INV_ICM42600_ACCEL_SCAN_TIMESTAMP,
};
static const struct iio_chan_spec_ext_info inv_icm42600_accel_ext_infos[] = {
INV_ICM42600_ACCEL_CHAN(IIO_MOD_Z, INV_ICM42600_ACCEL_SCAN_Z,
inv_icm42600_accel_ext_infos),
INV_ICM42600_TEMP_CHAN(INV_ICM42600_ACCEL_SCAN_TEMP),
+ IIO_CHAN_SOFT_TIMESTAMP(INV_ICM42600_ACCEL_SCAN_TIMESTAMP),
};
/*
- * IIO buffer data: size must be a power of 2
- * 8 bytes: 6 bytes acceleration and 2 bytes temperature
+ * IIO buffer data: size must be a power of 2 and timestamp aligned
+ * 16 bytes: 6 bytes acceleration, 2 bytes temperature, 8 bytes timestamp
*/
struct inv_icm42600_accel_buffer {
struct inv_icm42600_fifo_sensor_data accel;
int16_t temp;
+ int64_t timestamp __aligned(8);
};
#define INV_ICM42600_SCAN_MASK_ACCEL_3AXIS \
const unsigned long *scan_mask)
{
struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+ struct inv_icm42600_timestamp *ts = iio_priv(indio_dev);
struct inv_icm42600_sensor_conf conf = INV_ICM42600_SENSOR_CONF_INIT;
unsigned int fifo_en = 0;
unsigned int sleep_temp = 0;
}
/* update data FIFO write */
+ inv_icm42600_timestamp_apply_odr(ts, 0, 0, 0);
ret = inv_icm42600_buffer_set_fifo_en(st, fifo_en | st->fifo.en);
if (ret)
goto out_unlock;
return IIO_VAL_INT_PLUS_MICRO;
}
-static int inv_icm42600_accel_write_odr(struct inv_icm42600_state *st,
+static int inv_icm42600_accel_write_odr(struct iio_dev *indio_dev,
int val, int val2)
{
+ struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+ struct inv_icm42600_timestamp *ts = iio_priv(indio_dev);
struct device *dev = regmap_get_device(st->map);
unsigned int idx;
struct inv_icm42600_sensor_conf conf = INV_ICM42600_SENSOR_CONF_INIT;
pm_runtime_get_sync(dev);
mutex_lock(&st->lock);
+ ret = inv_icm42600_timestamp_update_odr(ts, inv_icm42600_odr_to_period(conf.odr),
+ iio_buffer_enabled(indio_dev));
+ if (ret)
+ goto out_unlock;
+
ret = inv_icm42600_set_accel_conf(st, &conf, NULL);
if (ret)
goto out_unlock;
iio_device_release_direct_mode(indio_dev);
return ret;
case IIO_CHAN_INFO_SAMP_FREQ:
- return inv_icm42600_accel_write_odr(st, val, val2);
+ return inv_icm42600_accel_write_odr(indio_dev, val, val2);
case IIO_CHAN_INFO_CALIBBIAS:
ret = iio_device_claim_direct_mode(indio_dev);
if (ret)
{
struct device *dev = regmap_get_device(st->map);
const char *name;
+ struct inv_icm42600_timestamp *ts;
struct iio_dev *indio_dev;
struct iio_buffer *buffer;
int ret;
if (!name)
return ERR_PTR(-ENOMEM);
- indio_dev = devm_iio_device_alloc(dev, 0);
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*ts));
if (!indio_dev)
return ERR_PTR(-ENOMEM);
if (!buffer)
return ERR_PTR(-ENOMEM);
+ ts = iio_priv(indio_dev);
+ inv_icm42600_timestamp_init(ts, inv_icm42600_odr_to_period(st->conf.accel.odr));
+
iio_device_set_drvdata(indio_dev, st);
indio_dev->name = name;
indio_dev->info = &inv_icm42600_accel_info;
int inv_icm42600_accel_parse_fifo(struct iio_dev *indio_dev)
{
struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+ struct inv_icm42600_timestamp *ts = iio_priv(indio_dev);
ssize_t i, size;
+ unsigned int no;
const void *accel, *gyro, *timestamp;
const int8_t *temp;
unsigned int odr;
+ int64_t ts_val;
struct inv_icm42600_accel_buffer buffer;
/* parse all fifo packets */
- for (i = 0; i < st->fifo.count; i += size) {
+ for (i = 0, no = 0; i < st->fifo.count; i += size, ++no) {
size = inv_icm42600_fifo_decode_packet(&st->fifo.data[i],
&accel, &gyro, &temp, ×tamp, &odr);
/* quit if error or FIFO is empty */
if (accel == NULL || !inv_icm42600_fifo_is_data_valid(accel))
continue;
+ /* update odr */
+ if (odr & INV_ICM42600_SENSOR_ACCEL)
+ inv_icm42600_timestamp_apply_odr(ts, st->fifo.period,
+ st->fifo.nb.total, no);
+
/* buffer is copied to userspace, zeroing it to avoid any data leak */
memset(&buffer, 0, sizeof(buffer));
memcpy(&buffer.accel, accel, sizeof(buffer.accel));
/* convert 8 bits FIFO temperature in high resolution format */
buffer.temp = temp ? (*temp * 64) : 0;
- iio_push_to_buffers(indio_dev, &buffer);
+ ts_val = inv_icm42600_timestamp_pop(ts);
+ iio_push_to_buffers_with_timestamp(indio_dev, &buffer, ts_val);
}
return 0;
#include <linux/iio/buffer.h>
#include "inv_icm42600.h"
+#include "inv_icm42600_timestamp.h"
#include "inv_icm42600_buffer.h"
/* FIFO header: 1 byte */
struct device *dev = regmap_get_device(st->map);
unsigned int sensor;
unsigned int *watermark;
+ struct inv_icm42600_timestamp *ts;
struct inv_icm42600_sensor_conf conf = INV_ICM42600_SENSOR_CONF_INIT;
unsigned int sleep_temp = 0;
unsigned int sleep_sensor = 0;
if (indio_dev == st->indio_gyro) {
sensor = INV_ICM42600_SENSOR_GYRO;
watermark = &st->fifo.watermark.gyro;
+ ts = iio_priv(st->indio_gyro);
} else if (indio_dev == st->indio_accel) {
sensor = INV_ICM42600_SENSOR_ACCEL;
watermark = &st->fifo.watermark.accel;
+ ts = iio_priv(st->indio_accel);
} else {
return -EINVAL;
}
if (!st->fifo.on)
ret = inv_icm42600_set_temp_conf(st, false, &sleep_temp);
+ inv_icm42600_timestamp_reset(ts);
+
out_unlock:
mutex_unlock(&st->lock);
int inv_icm42600_buffer_fifo_parse(struct inv_icm42600_state *st)
{
+ struct inv_icm42600_timestamp *ts;
int ret;
if (st->fifo.nb.total == 0)
return 0;
+ /* handle gyroscope timestamp and FIFO data parsing */
+ ts = iio_priv(st->indio_gyro);
+ inv_icm42600_timestamp_interrupt(ts, st->fifo.period, st->fifo.nb.total,
+ st->fifo.nb.gyro, st->timestamp.gyro);
if (st->fifo.nb.gyro > 0) {
ret = inv_icm42600_gyro_parse_fifo(st->indio_gyro);
if (ret)
return ret;
}
+ /* handle accelerometer timestamp and FIFO data parsing */
+ ts = iio_priv(st->indio_accel);
+ inv_icm42600_timestamp_interrupt(ts, st->fifo.period, st->fifo.nb.total,
+ st->fifo.nb.accel, st->timestamp.accel);
if (st->fifo.nb.accel > 0) {
ret = inv_icm42600_accel_parse_fifo(st->indio_accel);
if (ret)
int inv_icm42600_buffer_hwfifo_flush(struct inv_icm42600_state *st,
unsigned int count)
{
+ struct inv_icm42600_timestamp *ts;
+ int64_t gyro_ts, accel_ts;
int ret;
+ gyro_ts = iio_get_time_ns(st->indio_gyro);
+ accel_ts = iio_get_time_ns(st->indio_accel);
+
ret = inv_icm42600_buffer_fifo_read(st, count);
if (ret)
return ret;
return 0;
if (st->fifo.nb.gyro > 0) {
+ ts = iio_priv(st->indio_gyro);
+ inv_icm42600_timestamp_interrupt(ts, st->fifo.period,
+ st->fifo.nb.total, st->fifo.nb.gyro,
+ gyro_ts);
ret = inv_icm42600_gyro_parse_fifo(st->indio_gyro);
if (ret)
return ret;
}
if (st->fifo.nb.accel > 0) {
+ ts = iio_priv(st->indio_accel);
+ inv_icm42600_timestamp_interrupt(ts, st->fifo.period,
+ st->fifo.nb.total, st->fifo.nb.accel,
+ accel_ts);
ret = inv_icm42600_accel_parse_fifo(st->indio_accel);
if (ret)
return ret;
#include "inv_icm42600.h"
#include "inv_icm42600_buffer.h"
+#include "inv_icm42600_timestamp.h"
static const struct regmap_range_cfg inv_icm42600_regmap_ranges[] = {
{
return inv_icm42600_set_conf(st, hw->conf);
}
+static irqreturn_t inv_icm42600_irq_timestamp(int irq, void *_data)
+{
+ struct inv_icm42600_state *st = _data;
+
+ st->timestamp.gyro = iio_get_time_ns(st->indio_gyro);
+ st->timestamp.accel = iio_get_time_ns(st->indio_accel);
+
+ return IRQ_WAKE_THREAD;
+}
+
static irqreturn_t inv_icm42600_irq_handler(int irq, void *_data)
{
struct inv_icm42600_state *st = _data;
if (ret)
return ret;
- return devm_request_threaded_irq(dev, irq, NULL,
+ return devm_request_threaded_irq(dev, irq, inv_icm42600_irq_timestamp,
inv_icm42600_irq_handler, irq_type,
"inv_icm42600", st);
}
if (ret)
return ret;
+ ret = inv_icm42600_timestamp_setup(st);
+ if (ret)
+ return ret;
+
ret = inv_icm42600_buffer_init(st);
if (ret)
return ret;
#include "inv_icm42600.h"
#include "inv_icm42600_temp.h"
#include "inv_icm42600_buffer.h"
+#include "inv_icm42600_timestamp.h"
#define INV_ICM42600_GYRO_CHAN(_modifier, _index, _ext_info) \
{ \
INV_ICM42600_GYRO_SCAN_Y,
INV_ICM42600_GYRO_SCAN_Z,
INV_ICM42600_GYRO_SCAN_TEMP,
+ INV_ICM42600_GYRO_SCAN_TIMESTAMP,
};
static const struct iio_chan_spec_ext_info inv_icm42600_gyro_ext_infos[] = {
INV_ICM42600_GYRO_CHAN(IIO_MOD_Z, INV_ICM42600_GYRO_SCAN_Z,
inv_icm42600_gyro_ext_infos),
INV_ICM42600_TEMP_CHAN(INV_ICM42600_GYRO_SCAN_TEMP),
+ IIO_CHAN_SOFT_TIMESTAMP(INV_ICM42600_GYRO_SCAN_TIMESTAMP),
};
/*
- * IIO buffer data: size must be a power of 2
- * 8 bytes: 6 bytes angular velocity and 2 bytes temperature
+ * IIO buffer data: size must be a power of 2 and timestamp aligned
+ * 16 bytes: 6 bytes angular velocity, 2 bytes temperature, 8 bytes timestamp
*/
struct inv_icm42600_gyro_buffer {
struct inv_icm42600_fifo_sensor_data gyro;
int16_t temp;
+ int64_t timestamp __aligned(8);
};
#define INV_ICM42600_SCAN_MASK_GYRO_3AXIS \
const unsigned long *scan_mask)
{
struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+ struct inv_icm42600_timestamp *ts = iio_priv(indio_dev);
struct inv_icm42600_sensor_conf conf = INV_ICM42600_SENSOR_CONF_INIT;
unsigned int fifo_en = 0;
unsigned int sleep_gyro = 0;
}
/* update data FIFO write */
+ inv_icm42600_timestamp_apply_odr(ts, 0, 0, 0);
ret = inv_icm42600_buffer_set_fifo_en(st, fifo_en | st->fifo.en);
if (ret)
goto out_unlock;
return IIO_VAL_INT_PLUS_MICRO;
}
-static int inv_icm42600_gyro_write_odr(struct inv_icm42600_state *st,
+static int inv_icm42600_gyro_write_odr(struct iio_dev *indio_dev,
int val, int val2)
{
+ struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+ struct inv_icm42600_timestamp *ts = iio_priv(indio_dev);
struct device *dev = regmap_get_device(st->map);
unsigned int idx;
struct inv_icm42600_sensor_conf conf = INV_ICM42600_SENSOR_CONF_INIT;
pm_runtime_get_sync(dev);
mutex_lock(&st->lock);
+ ret = inv_icm42600_timestamp_update_odr(ts, inv_icm42600_odr_to_period(conf.odr),
+ iio_buffer_enabled(indio_dev));
+ if (ret)
+ goto out_unlock;
+
ret = inv_icm42600_set_gyro_conf(st, &conf, NULL);
if (ret)
goto out_unlock;
iio_device_release_direct_mode(indio_dev);
return ret;
case IIO_CHAN_INFO_SAMP_FREQ:
- return inv_icm42600_gyro_write_odr(st, val, val2);
+ return inv_icm42600_gyro_write_odr(indio_dev, val, val2);
case IIO_CHAN_INFO_CALIBBIAS:
ret = iio_device_claim_direct_mode(indio_dev);
if (ret)
{
struct device *dev = regmap_get_device(st->map);
const char *name;
+ struct inv_icm42600_timestamp *ts;
struct iio_dev *indio_dev;
struct iio_buffer *buffer;
int ret;
if (!name)
return ERR_PTR(-ENOMEM);
- indio_dev = devm_iio_device_alloc(dev, 0);
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*ts));
if (!indio_dev)
return ERR_PTR(-ENOMEM);
if (!buffer)
return ERR_PTR(-ENOMEM);
+ ts = iio_priv(indio_dev);
+ inv_icm42600_timestamp_init(ts, inv_icm42600_odr_to_period(st->conf.gyro.odr));
+
iio_device_set_drvdata(indio_dev, st);
indio_dev->name = name;
indio_dev->info = &inv_icm42600_gyro_info;
int inv_icm42600_gyro_parse_fifo(struct iio_dev *indio_dev)
{
struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+ struct inv_icm42600_timestamp *ts = iio_priv(indio_dev);
ssize_t i, size;
+ unsigned int no;
const void *accel, *gyro, *timestamp;
const int8_t *temp;
unsigned int odr;
+ int64_t ts_val;
struct inv_icm42600_gyro_buffer buffer;
/* parse all fifo packets */
- for (i = 0; i < st->fifo.count; i += size) {
+ for (i = 0, no = 0; i < st->fifo.count; i += size, ++no) {
size = inv_icm42600_fifo_decode_packet(&st->fifo.data[i],
&accel, &gyro, &temp, ×tamp, &odr);
/* quit if error or FIFO is empty */
if (gyro == NULL || !inv_icm42600_fifo_is_data_valid(gyro))
continue;
+ /* update odr */
+ if (odr & INV_ICM42600_SENSOR_GYRO)
+ inv_icm42600_timestamp_apply_odr(ts, st->fifo.period,
+ st->fifo.nb.total, no);
+
/* buffer is copied to userspace, zeroing it to avoid any data leak */
memset(&buffer, 0, sizeof(buffer));
memcpy(&buffer.gyro, gyro, sizeof(buffer.gyro));
/* convert 8 bits FIFO temperature in high resolution format */
buffer.temp = temp ? (*temp * 64) : 0;
- iio_push_to_buffers(indio_dev, &buffer);
+ ts_val = inv_icm42600_timestamp_pop(ts);
+ iio_push_to_buffers_with_timestamp(indio_dev, &buffer, ts_val);
}
return 0;
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2020 Invensense, Inc.
+ */
+
+#include <linux/kernel.h>
+#include <linux/regmap.h>
+#include <linux/math64.h>
+
+#include "inv_icm42600.h"
+#include "inv_icm42600_timestamp.h"
+
+/* internal chip period is 32kHz, 31250ns */
+#define INV_ICM42600_TIMESTAMP_PERIOD 31250
+/* allow a jitter of +/- 2% */
+#define INV_ICM42600_TIMESTAMP_JITTER 2
+/* compute min and max periods accepted */
+#define INV_ICM42600_TIMESTAMP_MIN_PERIOD(_p) \
+ (((_p) * (100 - INV_ICM42600_TIMESTAMP_JITTER)) / 100)
+#define INV_ICM42600_TIMESTAMP_MAX_PERIOD(_p) \
+ (((_p) * (100 + INV_ICM42600_TIMESTAMP_JITTER)) / 100)
+
+/* Add a new value inside an accumulator and update the estimate value */
+static void inv_update_acc(struct inv_icm42600_timestamp_acc *acc, uint32_t val)
+{
+ uint64_t sum = 0;
+ size_t i;
+
+ acc->values[acc->idx++] = val;
+ if (acc->idx >= ARRAY_SIZE(acc->values))
+ acc->idx = 0;
+
+ /* compute the mean of all stored values, use 0 as empty slot */
+ for (i = 0; i < ARRAY_SIZE(acc->values); ++i) {
+ if (acc->values[i] == 0)
+ break;
+ sum += acc->values[i];
+ }
+
+ acc->val = div_u64(sum, i);
+}
+
+void inv_icm42600_timestamp_init(struct inv_icm42600_timestamp *ts,
+ uint32_t period)
+{
+ /* initial odr for sensor after reset is 1kHz */
+ const uint32_t default_period = 1000000;
+
+ /* current multiplier and period values after reset */
+ ts->mult = default_period / INV_ICM42600_TIMESTAMP_PERIOD;
+ ts->period = default_period;
+ /* new set multiplier is the one from chip initialization */
+ ts->new_mult = period / INV_ICM42600_TIMESTAMP_PERIOD;
+
+ /* use theoretical value for chip period */
+ inv_update_acc(&ts->chip_period, INV_ICM42600_TIMESTAMP_PERIOD);
+}
+
+int inv_icm42600_timestamp_setup(struct inv_icm42600_state *st)
+{
+ unsigned int val;
+
+ /* enable timestamp register */
+ val = INV_ICM42600_TMST_CONFIG_TMST_TO_REGS_EN |
+ INV_ICM42600_TMST_CONFIG_TMST_EN;
+ return regmap_update_bits(st->map, INV_ICM42600_REG_TMST_CONFIG,
+ INV_ICM42600_TMST_CONFIG_MASK, val);
+}
+
+int inv_icm42600_timestamp_update_odr(struct inv_icm42600_timestamp *ts,
+ uint32_t period, bool fifo)
+{
+ /* when FIFO is on, prevent odr change if one is already pending */
+ if (fifo && ts->new_mult != 0)
+ return -EAGAIN;
+
+ ts->new_mult = period / INV_ICM42600_TIMESTAMP_PERIOD;
+
+ return 0;
+}
+
+static bool inv_validate_period(uint32_t period, uint32_t mult)
+{
+ const uint32_t chip_period = INV_ICM42600_TIMESTAMP_PERIOD;
+ uint32_t period_min, period_max;
+
+ /* check that period is acceptable */
+ period_min = INV_ICM42600_TIMESTAMP_MIN_PERIOD(chip_period) * mult;
+ period_max = INV_ICM42600_TIMESTAMP_MAX_PERIOD(chip_period) * mult;
+ if (period > period_min && period < period_max)
+ return true;
+ else
+ return false;
+}
+
+static bool inv_compute_chip_period(struct inv_icm42600_timestamp *ts,
+ uint32_t mult, uint32_t period)
+{
+ uint32_t new_chip_period;
+
+ if (!inv_validate_period(period, mult))
+ return false;
+
+ /* update chip internal period estimation */
+ new_chip_period = period / mult;
+ inv_update_acc(&ts->chip_period, new_chip_period);
+
+ return true;
+}
+
+void inv_icm42600_timestamp_interrupt(struct inv_icm42600_timestamp *ts,
+ uint32_t fifo_period, size_t fifo_nb,
+ size_t sensor_nb, int64_t timestamp)
+{
+ struct inv_icm42600_timestamp_interval *it;
+ int64_t delta, interval;
+ const uint32_t fifo_mult = fifo_period / INV_ICM42600_TIMESTAMP_PERIOD;
+ uint32_t period = ts->period;
+ int32_t m;
+ bool valid = false;
+
+ if (fifo_nb == 0)
+ return;
+
+ /* update interrupt timestamp and compute chip and sensor periods */
+ it = &ts->it;
+ it->lo = it->up;
+ it->up = timestamp;
+ delta = it->up - it->lo;
+ if (it->lo != 0) {
+ /* compute period: delta time divided by number of samples */
+ period = div_s64(delta, fifo_nb);
+ valid = inv_compute_chip_period(ts, fifo_mult, period);
+ /* update sensor period if chip internal period is updated */
+ if (valid)
+ ts->period = ts->mult * ts->chip_period.val;
+ }
+
+ /* no previous data, compute theoritical value from interrupt */
+ if (ts->timestamp == 0) {
+ /* elapsed time: sensor period * sensor samples number */
+ interval = (int64_t)ts->period * (int64_t)sensor_nb;
+ ts->timestamp = it->up - interval;
+ return;
+ }
+
+ /* if interrupt interval is valid, sync with interrupt timestamp */
+ if (valid) {
+ /* compute measured fifo_period */
+ fifo_period = fifo_mult * ts->chip_period.val;
+ /* delta time between last sample and last interrupt */
+ delta = it->lo - ts->timestamp;
+ /* if there are multiple samples, go back to first one */
+ while (delta >= (fifo_period * 3 / 2))
+ delta -= fifo_period;
+ /* compute maximal adjustment value */
+ m = INV_ICM42600_TIMESTAMP_MAX_PERIOD(ts->period) - ts->period;
+ if (delta > m)
+ delta = m;
+ else if (delta < -m)
+ delta = -m;
+ ts->timestamp += delta;
+ }
+}
+
+void inv_icm42600_timestamp_apply_odr(struct inv_icm42600_timestamp *ts,
+ uint32_t fifo_period, size_t fifo_nb,
+ unsigned int fifo_no)
+{
+ int64_t interval;
+ uint32_t fifo_mult;
+
+ if (ts->new_mult == 0)
+ return;
+
+ /* update to new multiplier and update period */
+ ts->mult = ts->new_mult;
+ ts->new_mult = 0;
+ ts->period = ts->mult * ts->chip_period.val;
+
+ /*
+ * After ODR change the time interval with the previous sample is
+ * undertermined (depends when the change occures). So we compute the
+ * timestamp from the current interrupt using the new FIFO period, the
+ * total number of samples and the current sample numero.
+ */
+ if (ts->timestamp != 0) {
+ /* compute measured fifo period */
+ fifo_mult = fifo_period / INV_ICM42600_TIMESTAMP_PERIOD;
+ fifo_period = fifo_mult * ts->chip_period.val;
+ /* computes time interval between interrupt and this sample */
+ interval = (int64_t)(fifo_nb - fifo_no) * (int64_t)fifo_period;
+ ts->timestamp = ts->it.up - interval;
+ }
+}
--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2020 Invensense, Inc.
+ */
+
+#ifndef INV_ICM42600_TIMESTAMP_H_
+#define INV_ICM42600_TIMESTAMP_H_
+
+#include <linux/kernel.h>
+
+struct inv_icm42600_state;
+
+/**
+ * struct inv_icm42600_timestamp_interval - timestamps interval
+ * @lo: interval lower bound
+ * @up: interval upper bound
+ */
+struct inv_icm42600_timestamp_interval {
+ int64_t lo;
+ int64_t up;
+};
+
+/**
+ * struct inv_icm42600_timestamp_acc - accumulator for computing an estimation
+ * @val: current estimation of the value, the mean of all values
+ * @idx: current index of the next free place in values table
+ * @values: table of all measured values, use for computing the mean
+ */
+struct inv_icm42600_timestamp_acc {
+ uint32_t val;
+ size_t idx;
+ uint32_t values[32];
+};
+
+/**
+ * struct inv_icm42600_timestamp - timestamp management states
+ * @it: interrupts interval timestamps
+ * @timestamp: store last timestamp for computing next data timestamp
+ * @mult: current internal period multiplier
+ * @new_mult: new set internal period multiplier (not yet effective)
+ * @period: measured current period of the sensor
+ * @chip_period: accumulator for computing internal chip period
+ */
+struct inv_icm42600_timestamp {
+ struct inv_icm42600_timestamp_interval it;
+ int64_t timestamp;
+ uint32_t mult;
+ uint32_t new_mult;
+ uint32_t period;
+ struct inv_icm42600_timestamp_acc chip_period;
+};
+
+void inv_icm42600_timestamp_init(struct inv_icm42600_timestamp *ts,
+ uint32_t period);
+
+int inv_icm42600_timestamp_setup(struct inv_icm42600_state *st);
+
+int inv_icm42600_timestamp_update_odr(struct inv_icm42600_timestamp *ts,
+ uint32_t period, bool fifo);
+
+void inv_icm42600_timestamp_interrupt(struct inv_icm42600_timestamp *ts,
+ uint32_t fifo_period, size_t fifo_nb,
+ size_t sensor_nb, int64_t timestamp);
+
+static inline int64_t
+inv_icm42600_timestamp_pop(struct inv_icm42600_timestamp *ts)
+{
+ ts->timestamp += ts->period;
+ return ts->timestamp;
+}
+
+void inv_icm42600_timestamp_apply_odr(struct inv_icm42600_timestamp *ts,
+ uint32_t fifo_period, size_t fifo_nb,
+ unsigned int fifo_no);
+
+static inline void
+inv_icm42600_timestamp_reset(struct inv_icm42600_timestamp *ts)
+{
+ const struct inv_icm42600_timestamp_interval interval_init = {0LL, 0LL};
+
+ ts->it = interval_init;
+ ts->timestamp = 0;
+}
+
+#endif
projects / linux.git / commitdiff