coreboot-libre-fam15h-rdimm/3rdparty/chromeec/common/motion_sense_fifo.c

409 lines
12 KiB
C

/* Copyright 2019 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "console.h"
#include "hwtimer.h"
#include "mkbp_event.h"
#include "motion_sense_fifo.h"
#include "queue.h"
#include "tablet_mode.h"
#include "util.h"
#define CPRINTS(format, args...) cprints(CC_MOTION_SENSE, format, ## args)
static inline int is_timestamp(struct ec_response_motion_sensor_data *data)
{
return data->flags & MOTIONSENSE_SENSOR_FLAG_TIMESTAMP;
}
/* Need to wake up the AP */
int wake_up_needed;
/* Number of element the AP should collect */
int fifo_queue_count;
int fifo_int_enabled;
struct queue motion_sense_fifo = QUEUE_NULL(
CONFIG_ACCEL_FIFO_SIZE, struct ec_response_motion_sensor_data);
int motion_sense_fifo_lost;
/**
* Staged metadata for the motion_sense_fifo.
* @read_ts: The timestamp at which the staged data was read. This value will
* serve as the upper bound for spreading
* @count: The total number of motion_sense_fifo entries that are currently
* staged.
* @sample_count: The total number of sensor readings per sensor that are
* currently staged.
* @requires_spreading: Flag used to shortcut the commit process. This should be
* true iff at least one of sample_count[] > 1
*/
struct fifo_staged {
uint32_t read_ts;
uint16_t count;
uint8_t sample_count[SENSOR_COUNT];
uint8_t requires_spreading;
};
static struct fifo_staged fifo_staged;
static inline struct ec_response_motion_sensor_data *
get_motion_sense_fifo_head(void)
{
return ((struct ec_response_motion_sensor_data *)
motion_sense_fifo.buffer) +
(motion_sense_fifo.state->head &
motion_sense_fifo.unit_bytes);
}
/**
* Pop one entry from the motion sense fifo. Poping will give priority to
* committed data (data residing between the head and tail of the queue). If no
* committed data is available (all the data is staged), then this function will
* remove the oldest staged data by moving both the head and tail.
*
* As a side-effect of this function, it'll updated any appropriate lost and
* count variables.
*
* WARNING: This function MUST be called from within a locked context of
* g_sensor_mutex.
*/
static void motion_sense_fifo_pop(void)
{
struct ec_response_motion_sensor_data *head =
get_motion_sense_fifo_head();
const size_t initial_count = queue_count(&motion_sense_fifo);
/* Check that we have something to pop. */
if (!initial_count && !fifo_staged.count)
return;
/*
* If all the data is staged (nothing in the committed queue), we'll
* need to move the head and the tail over to simulate poping from the
* staged data.
*/
if (!initial_count)
queue_advance_tail(&motion_sense_fifo, 1);
/*
* By not using queue_remove_unit we're avoiding an un-necessary memcpy.
*/
queue_advance_head(&motion_sense_fifo, 1);
motion_sense_fifo_lost++;
/* Increment lost counter if we have valid data. */
if (!is_timestamp(head))
motion_sensors[head->sensor_num].lost++;
/*
* We're done if the initial count was non-zero and we only advanced the
* head. Else, decrement the staged count and update staged metadata.
*/
if (initial_count)
return;
fifo_staged.count--;
/* If we removed a timestamp there's nothing else for us to do. */
if (is_timestamp(head))
return;
/*
* Decrement sample count, if the count was 2 before, we might not need
* to spread anymore. Loop through and check.
*/
if (--fifo_staged.sample_count[head->sensor_num] < 2) {
int i;
fifo_staged.requires_spreading = 0;
for (i = 0; i < SENSOR_COUNT; i++) {
if (fifo_staged.sample_count[i] > 1) {
fifo_staged.requires_spreading = 1;
break;
}
}
}
}
static void motion_sense_fifo_ensure_space(void)
{
/* If we already have space just bail. */
if (queue_space(&motion_sense_fifo) > fifo_staged.count)
return;
/*
* Pop at least 1 spot, but if all the following conditions are met we
* will continue to pop:
* 1. We're operating with tight timestamps.
* 2. The new head isn't a timestamp.
* 3. We have data that we can possibly pop.
*
* Removing more than one entry is needed because if we are using tight
* timestamps and we pop a timestamp, then the next head is data, the AP
* would assign a bad timestamp to it.
*/
do {
motion_sense_fifo_pop();
} while (IS_ENABLED(CONFIG_SENSOR_TIGHT_TIMESTAMPS) &&
!is_timestamp(get_motion_sense_fifo_head()) &&
queue_count(&motion_sense_fifo) + fifo_staged.count);
}
/*
* Do not use this function directly if you just want to add sensor data, use
* motion_sense_fifo_stage_data instead to get a proper timestamp too.
*/
static void motion_sense_fifo_stage_unit(
struct ec_response_motion_sensor_data *data,
struct motion_sensor_t *sensor,
int valid_data)
{
struct queue_chunk chunk;
int i;
mutex_lock(&g_sensor_mutex);
for (i = 0; i < valid_data; i++)
sensor->xyz[i] = data->data[i];
/* For valid sensors, check if AP really needs this data */
if (valid_data) {
int removed;
if (sensor->oversampling_ratio == 0) {
mutex_unlock(&g_sensor_mutex);
return;
}
removed = sensor->oversampling++;
sensor->oversampling %= sensor->oversampling_ratio;
if (removed != 0) {
mutex_unlock(&g_sensor_mutex);
return;
}
}
/* Make sure we have room for the data */
motion_sense_fifo_ensure_space();
mutex_unlock(&g_sensor_mutex);
if (data->flags & MOTIONSENSE_SENSOR_FLAG_WAKEUP)
wake_up_needed = 1;
if (IS_ENABLED(CONFIG_TABLET_MODE))
data->flags |= (tablet_get_mode() ?
MOTIONSENSE_SENSOR_FLAG_TABLET_MODE : 0);
/*
* Get the next writable block in the fifo. We don't need to lock this
* because it will always be past the tail and thus the AP will never
* read this until motion_sense_fifo_commit_data() is called.
*/
chunk = queue_get_write_chunk(
&motion_sense_fifo, fifo_staged.count);
if (!chunk.buffer) {
/*
* This should never happen since we already ensured there was
* space, but if there was a bug, we don't want to write to
* address 0. Just don't add any data to the queue instead.
*/
CPRINTS("Failed to get write chunk for new fifo data!");
return;
}
/*
* Save the data to the writable block and increment count. This data
* will now reside AFTER the tail of the queue and will not be visible
* to the AP until the motion_sense_fifo_commit_data() function is
* called. Because count is incremented, the following staged data will
* be written to the next available block and this one will remain
* staged.
*/
memcpy(chunk.buffer, data, motion_sense_fifo.unit_bytes);
fifo_staged.count++;
/*
* If we're using tight timestamps, and the current entry isn't a
* timestamp we'll increment the sample_count for the given sensor.
* If the new per-sensor sample count is greater than 1, we'll need to
* spread.
*/
if (IS_ENABLED(CONFIG_SENSOR_TIGHT_TIMESTAMPS) &&
!is_timestamp(data) &&
++fifo_staged.sample_count[data->sensor_num] > 1)
fifo_staged.requires_spreading = 1;
}
void motion_sense_insert_async_event(struct motion_sensor_t *sensor,
enum motion_sense_async_event evt)
{
struct ec_response_motion_sensor_data vector;
vector.flags = evt;
vector.timestamp = __hw_clock_source_read();
vector.sensor_num = sensor - motion_sensors;
motion_sense_fifo_stage_unit(&vector, sensor, 0);
motion_sense_fifo_commit_data();
}
void motion_sense_fifo_stage_timestamp(uint32_t timestamp)
{
struct ec_response_motion_sensor_data vector;
vector.flags = MOTIONSENSE_SENSOR_FLAG_TIMESTAMP;
vector.timestamp = timestamp;
vector.sensor_num = 0;
motion_sense_fifo_stage_unit(&vector, NULL, 0);
}
void motion_sense_fifo_stage_data(struct ec_response_motion_sensor_data *data,
struct motion_sensor_t *sensor,
int valid_data,
uint32_t time)
{
if (IS_ENABLED(CONFIG_SENSOR_TIGHT_TIMESTAMPS)) {
/* First entry, save the time for spreading later. */
if (!fifo_staged.count)
fifo_staged.read_ts = __hw_clock_source_read();
motion_sense_fifo_stage_timestamp(time);
}
motion_sense_fifo_stage_unit(data, sensor, valid_data);
}
/**
* Peek into the staged data at a given offset. This function performs no bound
* checking and is purely for convenience.
*/
static inline struct ec_response_motion_sensor_data *
motion_sense_peek_fifo_staged(size_t offset)
{
return (struct ec_response_motion_sensor_data *)
queue_get_write_chunk(&motion_sense_fifo, offset).buffer;
}
void motion_sense_fifo_commit_data(void)
{
/*
* Static data to use off stack. Note that next_timestamp should persist
* and is only updated if the timestamp from the sensor is greater.
*/
static uint32_t data_periods[SENSOR_COUNT];
static uint32_t next_timestamp[SENSOR_COUNT];
struct ec_response_motion_sensor_data *data;
int i, window, sensor_num;
/* Nothing staged, no work to do. */
if (!fifo_staged.count)
return;
/*
* If per-sensor event counts are never more than 1, no spreading is
* needed. This will also catch cases where tight timestamps aren't
* used.
*/
if (!fifo_staged.requires_spreading)
goto flush_data_end;
data = motion_sense_peek_fifo_staged(0);
/*
* Spreading only makes sense if tight timestamps are used. In such case
* entries are expected to be ordered: timestamp then data. If the first
* entry isn't a timestamp we must have gotten out of sync. Just commit
* all the data and skip the spreading.
*/
if (!is_timestamp(data)) {
CPRINTS("Spreading skipped, first entry is not a timestamp");
goto flush_data_end;
}
window = time_until(data->timestamp, fifo_staged.read_ts);
/* Update the data_periods as needed for this flush. */
for (i = 0; i < SENSOR_COUNT; i++) {
int period;
/* Skip empty sensors. */
if (!fifo_staged.sample_count[i])
continue;
period = motion_sensors[i].collection_rate;
/*
* Clamp the sample period to the MIN of collection_rate and the
* window length / sample counts.
*/
if (window)
period = MIN(period,
window / fifo_staged.sample_count[i]);
data_periods[i] = period;
}
/*
* Spread the timestamps.
*
* If we got this far that means that the tight timestamps config is
* enabled. This means that we can expect the staged entries to have 1
* or more timestamps followed by exactly 1 data entry. We'll loop
* through the timestamps until we get to data. We only need to update
* the timestamp right before it to keep things correct.
*/
for (i = 0; i < fifo_staged.count; i++) {
data = motion_sense_peek_fifo_staged(i);
/* Skip timestamp, we don't know the sensor number yet. */
if (is_timestamp(data))
continue;
/* Get the sensor number and point to the timestamp entry. */
sensor_num = data->sensor_num;
data = motion_sense_peek_fifo_staged(i - 1);
/* If the timestamp is after our computed next, skip ahead. */
if (time_after(data->timestamp, next_timestamp[sensor_num]))
next_timestamp[sensor_num] = data->timestamp;
/* Spread the timestamp and compute the expected next. */
data->timestamp = next_timestamp[sensor_num];
next_timestamp[sensor_num] += data_periods[sensor_num];
}
flush_data_end:
/* Advance the tail and clear the staged metadata. */
mutex_lock(&g_sensor_mutex);
queue_advance_tail(&motion_sense_fifo, fifo_staged.count);
mutex_unlock(&g_sensor_mutex);
/* Reset metadata for next staging cycle. */
memset(&fifo_staged, 0, sizeof(fifo_staged));
}
void motion_sense_get_fifo_info(
struct ec_response_motion_sense_fifo_info *fifo_info)
{
fifo_info->size = motion_sense_fifo.buffer_units;
mutex_lock(&g_sensor_mutex);
fifo_info->count = fifo_queue_count;
fifo_info->total_lost = motion_sense_fifo_lost;
mutex_unlock(&g_sensor_mutex);
fifo_info->timestamp = mkbp_last_event_time;
}
static int motion_sense_get_next_event(uint8_t *out)
{
union ec_response_get_next_data *data =
(union ec_response_get_next_data *)out;
/* out is not padded. It has one byte for the event type */
motion_sense_get_fifo_info(&data->sensor_fifo.info);
return sizeof(data->sensor_fifo);
}
DECLARE_EVENT_SOURCE(EC_MKBP_EVENT_SENSOR_FIFO, motion_sense_get_next_event);
inline int motion_sense_fifo_is_wake_up_needed(void)
{
return queue_space(&motion_sense_fifo) < CONFIG_ACCEL_FIFO_THRES ||
wake_up_needed;
}