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  */
15 struct 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  */
26 struct 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  */
37 struct 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  */
55 struct 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 
67 void inv_sensors_timestamp_init(struct inv_sensors_timestamp *ts,
68 				const struct inv_sensors_timestamp_chip *chip);
69 
70 int inv_sensors_timestamp_update_odr(struct inv_sensors_timestamp *ts,
71 				     uint32_t period, bool fifo);
72 
73 void 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 
inv_sensors_timestamp_pop(struct inv_sensors_timestamp * ts)77 static inline int64_t inv_sensors_timestamp_pop(struct inv_sensors_timestamp *ts)
78 {
79 	ts->timestamp += ts->period;
80 	return ts->timestamp;
81 }
82 
83 void 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 
inv_sensors_timestamp_reset(struct inv_sensors_timestamp * ts)87 static 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