1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Copyright (C) 2020 Invensense, Inc.
4 */
5
6#ifndef INV_SENSORS_TIMESTAMP_H_
7#define INV_SENSORS_TIMESTAMP_H_
8
9/**
10 * struct inv_sensors_timestamp_chip - chip internal properties
11 * @clock_period: internal clock period in ns
12 * @jitter: acceptable jitter in per-mille
13 * @init_period: chip initial period at reset in ns
14 */
15struct inv_sensors_timestamp_chip {
16 uint32_t clock_period;
17 uint32_t jitter;
18 uint32_t init_period;
19};
20
21/**
22 * struct inv_sensors_timestamp_interval - timestamps interval
23 * @lo: interval lower bound
24 * @up: interval upper bound
25 */
26struct inv_sensors_timestamp_interval {
27 int64_t lo;
28 int64_t up;
29};
30
31/**
32 * struct inv_sensors_timestamp_acc - accumulator for computing an estimation
33 * @val: current estimation of the value, the mean of all values
34 * @idx: current index of the next free place in values table
35 * @values: table of all measured values, use for computing the mean
36 */
37struct inv_sensors_timestamp_acc {
38 uint32_t val;
39 size_t idx;
40 uint32_t values[32];
41};
42
43/**
44 * struct inv_sensors_timestamp - timestamp management states
45 * @chip: chip internal characteristics
46 * @min_period: minimal acceptable clock period
47 * @max_period: maximal acceptable clock period
48 * @it: interrupts interval timestamps
49 * @timestamp: store last timestamp for computing next data timestamp
50 * @mult: current internal period multiplier
51 * @new_mult: new set internal period multiplier (not yet effective)
52 * @period: measured current period of the sensor
53 * @chip_period: accumulator for computing internal chip period
54 */
55struct inv_sensors_timestamp {
56 struct inv_sensors_timestamp_chip chip;
57 uint32_t min_period;
58 uint32_t max_period;
59 struct inv_sensors_timestamp_interval it;
60 int64_t timestamp;
61 uint32_t mult;
62 uint32_t new_mult;
63 uint32_t period;
64 struct inv_sensors_timestamp_acc chip_period;
65};
66
67void inv_sensors_timestamp_init(struct inv_sensors_timestamp *ts,
68 const struct inv_sensors_timestamp_chip *chip);
69
70int inv_sensors_timestamp_update_odr(struct inv_sensors_timestamp *ts,
71 uint32_t period, bool fifo);
72
73void inv_sensors_timestamp_interrupt(struct inv_sensors_timestamp *ts,
74 size_t sample_nb, int64_t timestamp);
75
76static inline int64_t inv_sensors_timestamp_pop(struct inv_sensors_timestamp *ts)
77{
78 ts->timestamp += ts->period;
79 return ts->timestamp;
80}
81
82void inv_sensors_timestamp_apply_odr(struct inv_sensors_timestamp *ts,
83 uint32_t fifo_period, size_t fifo_nb,
84 unsigned int fifo_no);
85
86static inline void inv_sensors_timestamp_reset(struct inv_sensors_timestamp *ts)
87{
88 const struct inv_sensors_timestamp_interval interval_init = {0LL, 0LL};
89
90 ts->it = interval_init;
91 ts->timestamp = 0;
92}
93
94#endif
95

source code of linux/include/linux/iio/common/inv_sensors_timestamp.h