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				     uint32_t fifo_period, size_t fifo_nb,
75				     size_t sensor_nb, int64_t timestamp);
76
77static inline int64_t inv_sensors_timestamp_pop(struct inv_sensors_timestamp *ts)
78{
79	ts->timestamp += ts->period;
80	return ts->timestamp;
81}
82
83void inv_sensors_timestamp_apply_odr(struct inv_sensors_timestamp *ts,
84				     uint32_t fifo_period, size_t fifo_nb,
85				     unsigned int fifo_no);
86
87static inline void inv_sensors_timestamp_reset(struct inv_sensors_timestamp *ts)
88{
89	const struct inv_sensors_timestamp_interval interval_init = {0LL, 0LL};
90
91	ts->it = interval_init;
92	ts->timestamp = 0;
93}
94
95#endif
96