diff --git a/drivers/platform/chrome/cros_ec_sensorhub_ring.c b/drivers/platform/chrome/cros_ec_sensorhub_ring.c
index a0a778999f30..aa184e554af2 100644
--- a/drivers/platform/chrome/cros_ec_sensorhub_ring.c
+++ b/drivers/platform/chrome/cros_ec_sensorhub_ring.c
@@ -18,6 +18,21 @@
 #include <linux/sort.h>
 #include <linux/slab.h>
 
+/* Precision of fixed point for the m values from the filter */
+#define M_PRECISION BIT(23)
+
+/* Only activate the filter once we have at least this many elements. */
+#define TS_HISTORY_THRESHOLD 8
+
+/*
+ * If we don't have any history entries for this long, empty the filter to
+ * make sure there are no big discontinuities.
+ */
+#define TS_HISTORY_BORED_US 500000
+
+/* To measure by how much the filter is overshooting, if it happens. */
+#define FUTURE_TS_ANALYTICS_COUNT_MAX 100
+
 static inline int cros_sensorhub_send_sample(
 		struct cros_ec_sensorhub *sensorhub,
 		struct cros_ec_sensors_ring_sample *sample)
@@ -91,9 +106,11 @@ EXPORT_SYMBOL_GPL(cros_ec_sensorhub_unregister_push_data);
 int cros_ec_sensorhub_ring_fifo_enable(struct cros_ec_sensorhub *sensorhub,
 				       bool on)
 {
-	int ret;
+	int ret, i;
 
 	mutex_lock(&sensorhub->cmd_lock);
+	for (i = 0; i < CROS_EC_SENSOR_MAX; i++)
+		sensorhub->last_batch_len[i] = 0;
 	sensorhub->params->cmd = MOTIONSENSE_CMD_FIFO_INT_ENABLE;
 	sensorhub->params->fifo_int_enable.enable = on;
 
@@ -110,6 +127,231 @@ int cros_ec_sensorhub_ring_fifo_enable(struct cros_ec_sensorhub *sensorhub,
 	return ret;
 }
 
+static int cros_ec_ring_median_cmp(const void *pv1, const void *pv2)
+{
+	s64 v1 = *(s64 *)pv1;
+	s64 v2 = *(s64 *)pv2;
+
+	if (v1 > v2)
+		return 1;
+	else if (v1 < v2)
+		return -1;
+	else
+		return 0;
+}
+
+/*
+ * cros_ec_ring_median: Gets median of an array of numbers
+ *
+ * For now it's implemented using an inefficient > O(n) sort then return
+ * the middle element. A more optimal method would be something like
+ * quickselect, but given that n = 64 we can probably live with it in the
+ * name of clarity.
+ *
+ * Warning: the input array gets modified (sorted)!
+ */
+static s64 cros_ec_ring_median(s64 *array, size_t length)
+{
+	sort(array, length, sizeof(s64), cros_ec_ring_median_cmp, NULL);
+	return array[length / 2];
+}
+
+/*
+ * IRQ Timestamp Filtering
+ *
+ * Lower down in cros_ec_ring_process_event(), for each sensor event we have to
+ * calculate it's timestamp in the AP timebase. There are 3 time points:
+ *   a - EC timebase, sensor event
+ *   b - EC timebase, IRQ
+ *   c - AP timebase, IRQ
+ *   a' - what we want: sensor even in AP timebase
+ *
+ * While a and b are recorded at accurate times (due to the EC real time
+ * nature); c is pretty untrustworthy, even though it's recorded the
+ * first thing in ec_irq_handler(). There is a very good change we'll get
+ * added lantency due to:
+ *   other irqs
+ *   ddrfreq
+ *   cpuidle
+ *
+ * Normally a' = c - b + a, but if we do that naive math any jitter in c
+ * will get coupled in a', which we don't want. We want a function
+ * a' = cros_ec_ring_ts_filter(a) which will filter out outliers in c.
+ *
+ * Think of a graph of AP time(b) on the y axis vs EC time(c) on the x axis.
+ * The slope of the line won't be exactly 1, there will be some clock drift
+ * between the 2 chips for various reasons (mechanical stress, temperature,
+ * voltage). We need to extrapolate values for a future x, without trusting
+ * recent y values too much.
+ *
+ * We use a median filter for the slope, then another median filter for the
+ * y-intercept to calculate this function:
+ *   dx[n] = x[n-1] - x[n]
+ *   dy[n] = x[n-1] - x[n]
+ *   m[n] = dy[n] / dx[n]
+ *   median_m = median(m[n-k:n])
+ *   error[i] = y[n-i] - median_m * x[n-i]
+ *   median_error = median(error[:k])
+ *   predicted_y = median_m * x + median_error
+ *
+ * Implementation differences from above:
+ * - Redefined y to be actually c - b, this gives us a lot more precision
+ * to do the math. (c-b)/b variations are more obvious than c/b variations.
+ * - Since we don't have floating point, any operations involving slope are
+ * done using fixed point math (*M_PRECISION)
+ * - Since x and y grow with time, we keep zeroing the graph (relative to
+ * the last sample), this way math involving *x[n-i] will not overflow
+ * - EC timestamps are kept in us, it improves the slope calculation precision
+ */
+
+/**
+ * cros_ec_ring_ts_filter_update() - Update filter history.
+ *
+ * @state: Filter information.
+ * @b: IRQ timestamp, EC timebase (us)
+ * @c: IRQ timestamp, AP timebase (ns)
+ *
+ * Given a new IRQ timestamp pair (EC and AP timebases), add it to the filter
+ * history.
+ */
+static void cros_ec_ring_ts_filter_update(
+			struct cros_ec_sensors_ts_filter_state *state,
+			s64 b, s64 c)
+{
+	s64 x, y;
+	s64 dx, dy;
+	s64 m; /* stored as *M_PRECISION */
+	s64 *m_history_copy = state->temp_buf;
+	s64 *error = state->temp_buf;
+	int i;
+
+	/* we trust b the most, that'll be our independent variable */
+	x = b;
+	/* y is the offset between AP and EC times, in ns */
+	y = c - b * 1000;
+
+	dx = (state->x_history[0] + state->x_offset) - x;
+	if (dx == 0)
+		return; /* we already have this irq in the history */
+	dy = (state->y_history[0] + state->y_offset) - y;
+	m = div64_s64(dy * M_PRECISION, dx);
+
+	/* Empty filter if we haven't seen any action in a while. */
+	if (-dx > TS_HISTORY_BORED_US)
+		state->history_len = 0;
+
+	/* Move everything over, also update offset to all absolute coords .*/
+	for (i = state->history_len - 1; i >= 1; i--) {
+		state->x_history[i] = state->x_history[i - 1] + dx;
+		state->y_history[i] = state->y_history[i - 1] + dy;
+
+		state->m_history[i] = state->m_history[i - 1];
+		/*
+		 * Also use the same loop to copy m_history for future
+		 * median extraction.
+		 */
+		m_history_copy[i] = state->m_history[i - 1];
+	}
+
+	/* Store the x and y, but remember offset is actually last sample. */
+	state->x_offset = x;
+	state->y_offset = y;
+	state->x_history[0] = 0;
+	state->y_history[0] = 0;
+
+	state->m_history[0] = m;
+	m_history_copy[0] = m;
+
+	if (state->history_len < CROS_EC_SENSORHUB_TS_HISTORY_SIZE)
+		state->history_len++;
+
+	/* Precalculate things for the filter. */
+	if (state->history_len > TS_HISTORY_THRESHOLD) {
+		state->median_m =
+		    cros_ec_ring_median(m_history_copy, state->history_len - 1);
+
+		/*
+		 * Calculate y-intercepts as if m_median is the slope and
+		 * points in the history are on the line. median_error will
+		 * still be in the offset coordinate system.
+		 */
+		for (i = 0; i < state->history_len; i++)
+			error[i] = state->y_history[i] -
+				div_s64(state->median_m * state->x_history[i],
+					M_PRECISION);
+		state->median_error =
+			cros_ec_ring_median(error, state->history_len);
+	} else {
+		state->median_m = 0;
+		state->median_error = 0;
+	}
+}
+
+/**
+ * cros_ec_ring_ts_filter() - Translate EC timebase timestamp to AP timebase
+ *
+ * @state: filter information.
+ * @x: any ec timestamp (us):
+ *
+ * cros_ec_ring_ts_filter(a) => a' event timestamp, AP timebase
+ * cros_ec_ring_ts_filter(b) => calculated timestamp when the EC IRQ
+ *                           should have happened on the AP, with low jitter
+ *
+ * Note: The filter will only activate once state->history_len goes
+ * over TS_HISTORY_THRESHOLD. Otherwise it'll just do the naive c - b + a
+ * transform.
+ *
+ * How to derive the formula, starting from:
+ *   f(x) = median_m * x + median_error
+ * That's the calculated AP - EC offset (at the x point in time)
+ * Undo the coordinate system transform:
+ *   f(x) = median_m * (x - x_offset) + median_error + y_offset
+ * Remember to undo the "y = c - b * 1000" modification:
+ *   f(x) = median_m * (x - x_offset) + median_error + y_offset + x * 1000
+ *
+ * Return: timestamp in AP timebase (ns)
+ */
+static s64 cros_ec_ring_ts_filter(struct cros_ec_sensors_ts_filter_state *state,
+				  s64 x)
+{
+	return div_s64(state->median_m * (x - state->x_offset), M_PRECISION)
+	       + state->median_error + state->y_offset + x * 1000;
+}
+
+/*
+ * Since a and b were originally 32 bit values from the EC,
+ * they overflow relatively often, casting is not enough, so we need to
+ * add an offset.
+ */
+static void cros_ec_ring_fix_overflow(s64 *ts,
+				const s64 overflow_period,
+				struct cros_ec_sensors_ec_overflow_state *state)
+{
+	s64 adjust;
+
+	*ts += state->offset;
+	if (abs(state->last - *ts) > (overflow_period / 2)) {
+		adjust = state->last > *ts ? overflow_period : -overflow_period;
+		state->offset += adjust;
+		*ts += adjust;
+	}
+	state->last = *ts;
+}
+
+static void cros_ec_ring_check_for_past_timestamp(
+				struct cros_ec_sensorhub *sensorhub,
+				struct cros_ec_sensors_ring_sample *sample)
+{
+	const u8 sensor_id = sample->sensor_id;
+
+	/* If this event is earlier than one we saw before... */
+	if (sensorhub->newest_sensor_event[sensor_id] > sample->timestamp)
+		/* mark it for spreading. */
+		sample->timestamp = sensorhub->last_batch_timestamp[sensor_id];
+	else
+		sensorhub->newest_sensor_event[sensor_id] = sample->timestamp;
+}
+
 /**
  * cros_ec_ring_process_event() - process one EC FIFO event
  *
@@ -142,26 +384,47 @@ static bool cros_ec_ring_process_event(struct cros_ec_sensorhub *sensorhub,
 		s64 a = in->timestamp;
 		s64 b = fifo_info->info.timestamp;
 		s64 c = fifo_timestamp;
-		s64 new_timestamp;
 
-		/*
-		 * disable filtering since we might add more jitter
-		 * if b is in a random point in time
-		 */
-		new_timestamp = c - b * 1000 + a * 1000;
+		cros_ec_ring_fix_overflow(&a, 1LL << 32,
+					  &sensorhub->overflow_a);
+		cros_ec_ring_fix_overflow(&b, 1LL << 32,
+					  &sensorhub->overflow_b);
+
+		if (sensorhub->tight_timestamps) {
+			cros_ec_ring_ts_filter_update(&sensorhub->filter, b, c);
+			*current_timestamp =
+				cros_ec_ring_ts_filter(&sensorhub->filter, a);
+		} else {
+			s64 new_timestamp;
+			/*
+			 * disable filtering since we might add more jitter
+			 * if b is in a random point in time
+			 */
+			new_timestamp = c - b * 1000 + a * 1000;
+			/*
+			 * The timestamp can be stale if we had to use the fifo
+			 * info timestamp.
+			 */
+			if (new_timestamp - *current_timestamp > 0)
+				*current_timestamp = new_timestamp;
+		}
+	}
 
+	if (in->flags & MOTIONSENSE_SENSOR_FLAG_ODR) {
+		sensorhub->last_batch_len[in->sensor_num] =
+			sensorhub->penultimate_batch_len[in->sensor_num] = 0;
 		/*
-		 * The timestamp can be stale if we had to use the fifo
-		 * info timestamp.
+		 * ODR change is only useful for the sensor_ring, it does not
+		 * convey information to clients.
 		 */
-		if (new_timestamp - *current_timestamp > 0)
-			*current_timestamp = new_timestamp;
+		return false;
 	}
 
 	if (in->flags & MOTIONSENSE_SENSOR_FLAG_FLUSH) {
 		out->sensor_id = in->sensor_num;
 		out->timestamp = *current_timestamp;
 		out->flag = in->flags;
+		sensorhub->last_batch_len[out->sensor_id] = 0;
 		/*
 		 * No other payload information provided with
 		 * flush ack.
@@ -176,7 +439,22 @@ static bool cros_ec_ring_process_event(struct cros_ec_sensorhub *sensorhub,
 	/* Regular sample */
 	out->sensor_id = in->sensor_num;
 	if (*current_timestamp - now > 0) {
-		/* If the timestamp is in the future. */
+		/*
+		 * This fix is needed to overcome the timestamp filter putting
+		 * events in the future.
+		 */
+		sensorhub->future_timestamp_total_ns +=
+			*current_timestamp - now;
+		if (++sensorhub->future_timestamp_count ==
+				FUTURE_TS_ANALYTICS_COUNT_MAX) {
+			s64 avg = div_s64(sensorhub->future_timestamp_total_ns,
+					sensorhub->future_timestamp_count);
+			dev_warn_ratelimited(sensorhub->dev,
+					     "100 timestamps in the future, %lldns shaved on average\n",
+					     avg);
+			sensorhub->future_timestamp_count = 0;
+			sensorhub->future_timestamp_total_ns = 0;
+		}
 		out->timestamp = now;
 	} else {
 		out->timestamp = *current_timestamp;
@@ -186,13 +464,194 @@ static bool cros_ec_ring_process_event(struct cros_ec_sensorhub *sensorhub,
 	for (axis = 0; axis < 3; axis++)
 		out->vector[axis] = in->data[axis];
 
+	if (sensorhub->tight_timestamps)
+		cros_ec_ring_check_for_past_timestamp(sensorhub, out);
 	return true;
 }
 
 /*
- * cros_ec_ring_spread_add: Calculate proper timestamps then
+ * cros_ec_ring_spread_add: Calculate proper timestamps then add to ringbuffer.
+ *
+ * Note: This is the new spreading code, assumes every sample's timestamp
+ * preceeds the sample. Run if tight_timestamps == true.
+ *
+ * Sometimes the EC receives only one interrupt (hence timestamp) for
+ * a batch of samples. Only the first sample will have the correct
+ * timestamp. So we must interpolate the other samples.
+ * We use the previous batch timestamp and our current batch timestamp
+ * as a way to calculate period, then spread the samples evenly.
+ *
+ * s0 int, 0ms
+ * s1 int, 10ms
+ * s2 int, 20ms
+ * 30ms point goes by, no interrupt, previous one is still asserted
+ * downloading s2 and s3
+ * s3 sample, 20ms (incorrect timestamp)
+ * s4 int, 40ms
+ *
+ * The batches are [(s0), (s1), (s2, s3), (s4)]. Since the 3rd batch
+ * has 2 samples in them, we adjust the timestamp of s3.
+ * s2 - s1 = 10ms, so s3 must be s2 + 10ms => 20ms. If s1 would have
+ * been part of a bigger batch things would have gotten a little
+ * more complicated.
+ *
+ * Note: we also assume another sensor sample doesn't break up a batch
+ * in 2 or more partitions. Example, there can't ever be a sync sensor
+ * in between S2 and S3. This simplifies the following code.
+ */
+static void cros_ec_ring_spread_add(
+				struct cros_ec_sensorhub *sensorhub,
+				unsigned long sensor_mask,
+				struct cros_ec_sensors_ring_sample *last_out)
+{
+	struct cros_ec_sensors_ring_sample *batch_start, *next_batch_start;
+	int id;
+
+	for_each_set_bit(id, &sensor_mask, BITS_PER_LONG) {
+		for (batch_start = sensorhub->ring; batch_start < last_out;
+		     batch_start = next_batch_start) {
+			/*
+			 * For each batch (where all samples have the same
+			 * timestamp).
+			 */
+			int batch_len, sample_idx;
+			struct cros_ec_sensors_ring_sample *batch_end =
+				batch_start;
+			struct cros_ec_sensors_ring_sample *s;
+			s64 batch_timestamp = batch_start->timestamp;
+			s64 sample_period;
+
+			/*
+			 * Skip over batches that start with the sensor types
+			 * we're not looking at right now.
+			 */
+			if (batch_start->sensor_id != id) {
+				next_batch_start = batch_start + 1;
+				continue;
+			}
+
+			/*
+			 * Do not start a batch
+			 * from a flush, as it happens asynchronously to the
+			 * regular flow of events.
+			 */
+			if (batch_start->flag & MOTIONSENSE_SENSOR_FLAG_FLUSH) {
+				cros_sensorhub_send_sample(sensorhub,
+							   batch_start);
+				next_batch_start = batch_start + 1;
+				continue;
+			}
+
+			if (batch_start->timestamp <=
+			    sensorhub->last_batch_timestamp[id]) {
+				batch_timestamp =
+					sensorhub->last_batch_timestamp[id];
+				batch_len = sensorhub->last_batch_len[id];
+
+				sample_idx = batch_len;
+
+				sensorhub->last_batch_timestamp[id] =
+				  sensorhub->penultimate_batch_timestamp[id];
+				sensorhub->last_batch_len[id] =
+				  sensorhub->penultimate_batch_len[id];
+			} else {
+				/*
+				 * Push first sample in the batch to the,
+				 * kifo, it's guaranteed to be correct, the
+				 * rest will follow later on.
+				 */
+				sample_idx = 1;
+				batch_len = 1;
+				cros_sensorhub_send_sample(sensorhub,
+							   batch_start);
+				batch_start++;
+			}
+
+			/* Find all samples have the same timestamp. */
+			for (s = batch_start; s < last_out; s++) {
+				if (s->sensor_id != id)
+					/*
+					 * Skip over other sensor types that
+					 * are interleaved, don't count them.
+					 */
+					continue;
+				if (s->timestamp != batch_timestamp)
+					/* we discovered the next batch */
+					break;
+				if (s->flag & MOTIONSENSE_SENSOR_FLAG_FLUSH)
+					/* break on flush packets */
+					break;
+				batch_end = s;
+				batch_len++;
+			}
+
+			if (batch_len == 1)
+				goto done_with_this_batch;
+
+			/* Can we calculate period? */
+			if (sensorhub->last_batch_len[id] == 0) {
+				dev_warn(sensorhub->dev, "Sensor %d: lost %d samples when spreading\n",
+					 id, batch_len - 1);
+				goto done_with_this_batch;
+				/*
+				 * Note: we're dropping the rest of the samples
+				 * in this batch since we have no idea where
+				 * they're supposed to go without a period
+				 * calculation.
+				 */
+			}
+
+			sample_period = div_s64(batch_timestamp -
+					sensorhub->last_batch_timestamp[id],
+					sensorhub->last_batch_len[id]);
+			dev_dbg(sensorhub->dev,
+				"Adjusting %d samples, sensor %d last_batch @%lld (%d samples) batch_timestamp=%lld => period=%lld\n",
+				batch_len, id,
+				sensorhub->last_batch_timestamp[id],
+				sensorhub->last_batch_len[id],
+				batch_timestamp,
+				sample_period);
+
+			/*
+			 * Adjust timestamps of the samples then push them to
+			 * kfifo.
+			 */
+			for (s = batch_start; s <= batch_end; s++) {
+				if (s->sensor_id != id)
+					/*
+					 * Skip over other sensor types that
+					 * are interleaved, don't change them.
+					 */
+					continue;
+
+				s->timestamp = batch_timestamp +
+					sample_period * sample_idx;
+				sample_idx++;
+
+				cros_sensorhub_send_sample(sensorhub, s);
+			}
+
+done_with_this_batch:
+			sensorhub->penultimate_batch_timestamp[id] =
+				sensorhub->last_batch_timestamp[id];
+			sensorhub->penultimate_batch_len[id] =
+				sensorhub->last_batch_len[id];
+
+			sensorhub->last_batch_timestamp[id] = batch_timestamp;
+			sensorhub->last_batch_len[id] = batch_len;
+
+			next_batch_start = batch_end + 1;
+		}
+	}
+}
+
+/*
+ * cros_ec_ring_spread_add_legacy: Calculate proper timestamps then
  * add to ringbuffer (legacy).
  *
+ * Note: This assumes we're running old firmware, where every sample's timestamp
+ * is after the sample. Run if tight_timestamps == false.
+ *
  * If there is a sample with a proper timestamp
  *                        timestamp | count
  * older_unprocess_out --> TS1      | 1
@@ -210,7 +669,8 @@ static bool cros_ec_ring_process_event(struct cros_ec_sensorhub *sensorhub,
  * out -->                 TS1      | 3
  * We know have [TS1+1/3, TS1+2/3, current timestamp]
  */
-static void cros_ec_ring_spread_add(struct cros_ec_sensorhub *sensorhub,
+static void cros_ec_ring_spread_add_legacy(
+				struct cros_ec_sensorhub *sensorhub,
 				unsigned long sensor_mask,
 				s64 current_timestamp,
 				struct cros_ec_sensors_ring_sample *last_out)
@@ -394,7 +854,8 @@ static void cros_ec_sensorhub_ring_handler(struct cros_ec_sensorhub *sensorhub)
 	 * the AP is slow to respond to the IRQ, the EC may have added new
 	 * samples. Use the FIFO info timestamp as last timestamp then.
 	 */
-	if ((last_out - 1)->timestamp == current_timestamp)
+	if (!sensorhub->tight_timestamps &&
+	    (last_out - 1)->timestamp == current_timestamp)
 		current_timestamp = fifo_timestamp;
 
 	/* Warn on lost samples. */
@@ -408,6 +869,7 @@ static void cros_ec_sensorhub_ring_handler(struct cros_ec_sensorhub *sensorhub)
 				dev_warn_ratelimited(sensorhub->dev,
 						     "Sensor %d: lost: %d out of %d\n",
 						     i, lost, total_lost);
+				sensorhub->last_batch_len[i] = 0;
 			}
 		}
 	}
@@ -415,8 +877,11 @@ static void cros_ec_sensorhub_ring_handler(struct cros_ec_sensorhub *sensorhub)
 	/*
 	 * Spread samples in case of batching, then add them to the ringbuffer.
 	 */
-	cros_ec_ring_spread_add(sensorhub, sensor_mask,
-			current_timestamp, last_out);
+	if (sensorhub->tight_timestamps)
+		cros_ec_ring_spread_add(sensorhub, sensor_mask, last_out);
+	else
+		cros_ec_ring_spread_add_legacy(sensorhub, sensor_mask,
+					       current_timestamp, last_out);
 
 ring_handler_end:
 	sensorhub->fifo_timestamp[CROS_EC_SENSOR_LAST_TS] = current_timestamp;
@@ -494,6 +959,9 @@ int cros_ec_sensorhub_ring_add(struct cros_ec_sensorhub *sensorhub)
 	sensorhub->fifo_timestamp[CROS_EC_SENSOR_LAST_TS] =
 		cros_ec_get_time_ns();
 
+	sensorhub->tight_timestamps = cros_ec_check_features(ec,
+				EC_FEATURE_MOTION_SENSE_TIGHT_TIMESTAMPS);
+
 	/* register the notifier that will act as a top half interrupt. */
 	sensorhub->notifier.notifier_call = cros_ec_sensorhub_event;
 	ret = blocking_notifier_chain_register(&ec->ec_dev->event_notifier,
diff --git a/include/linux/platform_data/cros_ec_sensorhub.h b/include/linux/platform_data/cros_ec_sensorhub.h
index 5aaaa6cb012a..56d84551c547 100644
--- a/include/linux/platform_data/cros_ec_sensorhub.h
+++ b/include/linux/platform_data/cros_ec_sensorhub.h
@@ -68,7 +68,44 @@ struct cros_ec_sensors_ring_sample {
 	s64 timestamp;
 } __packed;
 
+/* State used for cros_ec_ring_fix_overflow */
+struct cros_ec_sensors_ec_overflow_state {
+	s64 offset;
+	s64 last;
+};
+
+/* Length of the filter, how long to remember entries for */
+#define CROS_EC_SENSORHUB_TS_HISTORY_SIZE 64
+
 /**
+ * struct cros_ec_sensors_ts_filter_state - Timestamp filetr state.
+ *
+ * @x_offset: x is EC interrupt time. x_offset its last value.
+ * @y_offset: y is the difference between AP and EC time, y_offset its last
+ *            value.
+ * @x_history: The past history of x, relative to x_offset.
+ * @y_history: The past history of y, relative to y_offset.
+ * @m_history: rate between y and x.
+ * @history_len: Amount of valid historic data in the arrays.
+ * @temp_buf: Temporary buffer used when updating the filter.
+ * @median_m: median value of m_history
+ * @median_error: final error to apply to AP interrupt timestamp to get the
+ *                "true timestamp" the event occurred.
+ */
+struct cros_ec_sensors_ts_filter_state {
+	s64 x_offset, y_offset;
+	s64 x_history[CROS_EC_SENSORHUB_TS_HISTORY_SIZE];
+	s64 y_history[CROS_EC_SENSORHUB_TS_HISTORY_SIZE];
+	s64 m_history[CROS_EC_SENSORHUB_TS_HISTORY_SIZE];
+	int history_len;
+
+	s64 temp_buf[CROS_EC_SENSORHUB_TS_HISTORY_SIZE];
+
+	s64 median_m;
+	s64 median_error;
+};
+
+/*
  * struct cros_ec_sensorhub - Sensor Hub device data.
  *
  * @dev:          Device object, mostly used for logging.
@@ -82,6 +119,28 @@ struct cros_ec_sensors_ring_sample {
  * @fifo_timestamp: array for event timestamp and spreading.
  * @fifo_info: copy of FIFO information coming from the EC.
  * @fifo_size: size of the ring.
+ *
+ * @penultimate_batch_timestamp: array of last but one batch timestamps.
+ *  Used for timestamp spreading calculations when a batch shows up.
+ * @penultimate_batch_len: array of last but one batch length.
+ * @last_batch_timestamp: last batch timestamp array.
+ * @last_batch_len: last batch length array.
+ * @newest_sensor_event: last sensor timestamp.
+ * @overflow_a: for handling timestamp overflow for a time (sensor events)
+ * @overflow_b: for handling timestamp overflow for b time (ec interrupts)
+ * @filter: medium fileter structure.
+ * @tight_timestamps: Set to truen when EC support tight timestamping:
+ *  The timestamps reported from the EC have low jitter.
+ *  Timestamps also come before every sample.
+ *  Set either by feature bits coming from the EC or userspace.
+ *
+ * @future_timestamp_count : Statistics used to compute shaved time.
+ *  This occures when timestamp interpolation from EC time to AP time
+ *  accidentally puts timestamps in the future. These timestamps are clamped
+ *  to `now` and these count/total_ns maintain the statistics for
+ *  how much time was removed in a given period.
+ * @future_timestamp_total_ns: Total amount of time shaved.
+ *
  * @push_data: array of callback to send datums to iio sensor object.
  */
 struct cros_ec_sensorhub {
@@ -101,6 +160,22 @@ struct cros_ec_sensorhub {
 	struct cros_ec_fifo_info fifo_info;
 	int    fifo_size;
 
+	s64 penultimate_batch_timestamp[CROS_EC_SENSOR_MAX];
+	int penultimate_batch_len[CROS_EC_SENSOR_MAX];
+	s64 last_batch_timestamp[CROS_EC_SENSOR_MAX];
+	int last_batch_len[CROS_EC_SENSOR_MAX];
+	s64 newest_sensor_event[CROS_EC_SENSOR_MAX];
+
+	struct cros_ec_sensors_ec_overflow_state overflow_a;
+	struct cros_ec_sensors_ec_overflow_state overflow_b;
+
+	struct cros_ec_sensors_ts_filter_state filter;
+
+	int tight_timestamps;
+
+	s32 future_timestamp_count;
+	s64 future_timestamp_total_ns;
+
 	struct cros_ec_sensorhub_sensor_push_data push_data[
 		CROS_EC_SENSOR_PDEV_MAX];
 };
