1 files changed, 95 insertions, 0 deletions
diff --git a/include/linux/iio/common/inv_sensors_timestamp.h b/include/linux/iio/common/inv_sensors_timestamp.h
new file mode 100644
index 000000000000..a47d304d1ba7
--- /dev/null
+++ b/include/linux/iio/common/inv_sensors_timestamp.h
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2020 Invensense, Inc.
+ */
+
+#ifndef INV_SENSORS_TIMESTAMP_H_
+#define INV_SENSORS_TIMESTAMP_H_
+
+/**
+ * struct inv_sensors_timestamp_chip - chip internal properties
+ * @clock_period:	internal clock period in ns
+ * @jitter:		acceptable jitter in per-mille
+ * @init_period:	chip initial period at reset in ns
+ */
+struct inv_sensors_timestamp_chip {
+	uint32_t clock_period;
+	uint32_t jitter;
+	uint32_t init_period;
+};
+
+/**
+ * struct inv_sensors_timestamp_interval - timestamps interval
+ * @lo:	interval lower bound
+ * @up:	interval upper bound
+ */
+struct inv_sensors_timestamp_interval {
+	int64_t lo;
+	int64_t up;
+};
+
+/**
+ * struct inv_sensors_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_sensors_timestamp_acc {
+	uint32_t val;
+	size_t idx;
+	uint32_t values[32];
+};
+
+/**
+ * struct inv_sensors_timestamp - timestamp management states
+ * @chip:		chip internal characteristics
+ * @min_period:		minimal acceptable clock period
+ * @max_period:		maximal acceptable clock period
+ * @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_sensors_timestamp {
+	struct inv_sensors_timestamp_chip chip;
+	uint32_t min_period;
+	uint32_t max_period;
+	struct inv_sensors_timestamp_interval it;
+	int64_t timestamp;
+	uint32_t mult;
+	uint32_t new_mult;
+	uint32_t period;
+	struct inv_sensors_timestamp_acc chip_period;
+};
+
+void inv_sensors_timestamp_init(struct inv_sensors_timestamp *ts,
+				const struct inv_sensors_timestamp_chip *chip);
+
+int inv_sensors_timestamp_update_odr(struct inv_sensors_timestamp *ts,
+				     uint32_t period, bool fifo);
+
+void inv_sensors_timestamp_interrupt(struct inv_sensors_timestamp *ts,
+				     uint32_t fifo_period, size_t fifo_nb,
+				     size_t sensor_nb, int64_t timestamp);
+
+static inline int64_t inv_sensors_timestamp_pop(struct inv_sensors_timestamp *ts)
+{
+	ts->timestamp += ts->period;
+	return ts->timestamp;
+}
+
+void inv_sensors_timestamp_apply_odr(struct inv_sensors_timestamp *ts,
+				     uint32_t fifo_period, size_t fifo_nb,
+				     unsigned int fifo_no);
+
+static inline void inv_sensors_timestamp_reset(struct inv_sensors_timestamp *ts)
+{
+	const struct inv_sensors_timestamp_interval interval_init = {0LL, 0LL};
+
+	ts->it = interval_init;
+	ts->timestamp = 0;
+}
+
+#endif