blob: 0ecce6aa69d5e3a1ade4ef14b12b1141b5e4be69 [file] [log] [blame]
/* SPDX-License-Identifier: GPL-2.0 */
* Chrome OS EC MEMS Sensor Hub driver.
* Copyright 2019 Google LLC
#include <linux/ktime.h>
#include <linux/mutex.h>
#include <linux/notifier.h>
#include <linux/platform_data/cros_ec_commands.h>
struct iio_dev;
* struct cros_ec_sensor_platform - ChromeOS EC sensor platform information.
* @sensor_num: Id of the sensor, as reported by the EC.
struct cros_ec_sensor_platform {
u8 sensor_num;
* typedef cros_ec_sensorhub_push_data_cb_t - Callback function to send datum
* to specific sensors.
* @indio_dev: The IIO device that will process the sample.
* @data: Vector array of the ring sample.
* @timestamp: Timestamp in host timespace when the sample was acquired by
* the EC.
typedef int (*cros_ec_sensorhub_push_data_cb_t)(struct iio_dev *indio_dev,
s16 *data,
s64 timestamp);
struct cros_ec_sensorhub_sensor_push_data {
struct iio_dev *indio_dev;
cros_ec_sensorhub_push_data_cb_t push_data_cb;
enum {
struct cros_ec_sensors_ring_sample {
u8 sensor_id;
u8 flag;
s16 vector[3];
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 */
* 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;
int history_len;
s64 median_m;
s64 median_error;
/* struct cros_ec_sensors_ts_batch_state - State of batch of a single sensor.
* Use to store information to batch data using median fileter information.
* @penul_ts: last but one batch timestamp (penultimate timestamp).
* Used for timestamp spreading calculations
* when a batch shows up.
* @penul_len: last but one batch length.
* @last_ts: Last batch timestam.
* @last_len: Last batch length.
* @newest_sensor_event: Last sensor timestamp.
struct cros_ec_sensors_ts_batch_state {
s64 penul_ts;
int penul_len;
s64 last_ts;
int last_len;
s64 newest_sensor_event;
* struct cros_ec_sensorhub - Sensor Hub device data.
* @dev: Device object, mostly used for logging.
* @ec: Embedded Controller where the hub is located.
* @sensor_num: Number of MEMS sensors present in the EC.
* @msg: Structure to send FIFO requests.
* @params: Pointer to parameters in msg.
* @resp: Pointer to responses in msg.
* @cmd_lock : Lock for sending msg.
* @notifier: Notifier to kick the FIFO interrupt.
* @ring: Preprocessed ring to store events.
* @fifo_timestamp: Array for event timestamp and spreading.
* @fifo_info: Copy of FIFO information coming from the EC.
* @fifo_size: Size of the ring.
* @batch_state: Per sensor information of the last batches received.
* @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 occurs 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 {
struct device *dev;
struct cros_ec_dev *ec;
int sensor_num;
struct cros_ec_command *msg;
struct ec_params_motion_sense *params;
struct ec_response_motion_sense *resp;
struct mutex cmd_lock; /* Lock for protecting msg structure. */
struct notifier_block notifier;
struct cros_ec_sensors_ring_sample *ring;
ktime_t fifo_timestamp[CROS_EC_SENSOR_ALL_TS];
struct ec_response_motion_sense_fifo_info *fifo_info;
int fifo_size;
struct cros_ec_sensors_ts_batch_state *batch_state;
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;
int cros_ec_sensorhub_register_push_data(struct cros_ec_sensorhub *sensorhub,
u8 sensor_num,
struct iio_dev *indio_dev,
cros_ec_sensorhub_push_data_cb_t cb);
void cros_ec_sensorhub_unregister_push_data(struct cros_ec_sensorhub *sensorhub,
u8 sensor_num);
int cros_ec_sensorhub_ring_allocate(struct cros_ec_sensorhub *sensorhub);
int cros_ec_sensorhub_ring_add(struct cros_ec_sensorhub *sensorhub);
void cros_ec_sensorhub_ring_remove(void *arg);
int cros_ec_sensorhub_ring_fifo_enable(struct cros_ec_sensorhub *sensorhub,
bool on);