195 lines
6.1 KiB
C
195 lines
6.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Chrome OS EC MEMS Sensor Hub driver.
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*
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* Copyright 2019 Google LLC
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*/
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#ifndef __LINUX_PLATFORM_DATA_CROS_EC_SENSORHUB_H
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#define __LINUX_PLATFORM_DATA_CROS_EC_SENSORHUB_H
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#include <linux/ktime.h>
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#include <linux/mutex.h>
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#include <linux/notifier.h>
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#include <linux/platform_data/cros_ec_commands.h>
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struct iio_dev;
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/**
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* struct cros_ec_sensor_platform - ChromeOS EC sensor platform information.
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* @sensor_num: Id of the sensor, as reported by the EC.
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*/
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struct cros_ec_sensor_platform {
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u8 sensor_num;
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};
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/**
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* typedef cros_ec_sensorhub_push_data_cb_t - Callback function to send datum
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* to specific sensors.
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*
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* @indio_dev: The IIO device that will process the sample.
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* @data: Vector array of the ring sample.
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* @timestamp: Timestamp in host timespace when the sample was acquired by
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* the EC.
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*/
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typedef int (*cros_ec_sensorhub_push_data_cb_t)(struct iio_dev *indio_dev,
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s16 *data,
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s64 timestamp);
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struct cros_ec_sensorhub_sensor_push_data {
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struct iio_dev *indio_dev;
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cros_ec_sensorhub_push_data_cb_t push_data_cb;
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};
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enum {
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CROS_EC_SENSOR_LAST_TS,
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CROS_EC_SENSOR_NEW_TS,
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CROS_EC_SENSOR_ALL_TS
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};
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struct cros_ec_sensors_ring_sample {
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u8 sensor_id;
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u8 flag;
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s16 vector[3];
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s64 timestamp;
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} __packed;
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/* State used for cros_ec_ring_fix_overflow */
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struct cros_ec_sensors_ec_overflow_state {
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s64 offset;
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s64 last;
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};
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/* Length of the filter, how long to remember entries for */
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#define CROS_EC_SENSORHUB_TS_HISTORY_SIZE 64
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/**
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* struct cros_ec_sensors_ts_filter_state - Timestamp filetr state.
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*
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* @x_offset: x is EC interrupt time. x_offset its last value.
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* @y_offset: y is the difference between AP and EC time, y_offset its last
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* value.
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* @x_history: The past history of x, relative to x_offset.
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* @y_history: The past history of y, relative to y_offset.
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* @m_history: rate between y and x.
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* @history_len: Amount of valid historic data in the arrays.
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* @temp_buf: Temporary buffer used when updating the filter.
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* @median_m: median value of m_history
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* @median_error: final error to apply to AP interrupt timestamp to get the
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* "true timestamp" the event occurred.
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*/
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struct cros_ec_sensors_ts_filter_state {
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s64 x_offset, y_offset;
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s64 x_history[CROS_EC_SENSORHUB_TS_HISTORY_SIZE];
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s64 y_history[CROS_EC_SENSORHUB_TS_HISTORY_SIZE];
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s64 m_history[CROS_EC_SENSORHUB_TS_HISTORY_SIZE];
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int history_len;
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s64 temp_buf[CROS_EC_SENSORHUB_TS_HISTORY_SIZE];
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s64 median_m;
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s64 median_error;
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};
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/* struct cros_ec_sensors_ts_batch_state - State of batch of a single sensor.
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*
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* Use to store information to batch data using median fileter information.
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*
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* @penul_ts: last but one batch timestamp (penultimate timestamp).
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* Used for timestamp spreading calculations
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* when a batch shows up.
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* @penul_len: last but one batch length.
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* @last_ts: Last batch timestam.
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* @last_len: Last batch length.
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* @newest_sensor_event: Last sensor timestamp.
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*/
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struct cros_ec_sensors_ts_batch_state {
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s64 penul_ts;
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int penul_len;
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s64 last_ts;
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int last_len;
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s64 newest_sensor_event;
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};
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/*
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* struct cros_ec_sensorhub - Sensor Hub device data.
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*
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* @dev: Device object, mostly used for logging.
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* @ec: Embedded Controller where the hub is located.
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* @sensor_num: Number of MEMS sensors present in the EC.
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* @msg: Structure to send FIFO requests.
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* @params: Pointer to parameters in msg.
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* @resp: Pointer to responses in msg.
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* @cmd_lock : Lock for sending msg.
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* @notifier: Notifier to kick the FIFO interrupt.
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* @ring: Preprocessed ring to store events.
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* @fifo_timestamp: Array for event timestamp and spreading.
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* @fifo_info: Copy of FIFO information coming from the EC.
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* @fifo_size: Size of the ring.
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* @batch_state: Per sensor information of the last batches received.
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* @overflow_a: For handling timestamp overflow for a time (sensor events)
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* @overflow_b: For handling timestamp overflow for b time (ec interrupts)
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* @filter: Medium fileter structure.
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* @tight_timestamps: Set to truen when EC support tight timestamping:
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* The timestamps reported from the EC have low jitter.
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* Timestamps also come before every sample. Set either
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* by feature bits coming from the EC or userspace.
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* @future_timestamp_count: Statistics used to compute shaved time.
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* This occurs when timestamp interpolation from EC
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* time to AP time accidentally puts timestamps in
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* the future. These timestamps are clamped to
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* `now` and these count/total_ns maintain the
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* statistics for how much time was removed in a
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* given period.
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* @future_timestamp_total_ns: Total amount of time shaved.
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* @push_data: Array of callback to send datums to iio sensor object.
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*/
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struct cros_ec_sensorhub {
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struct device *dev;
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struct cros_ec_dev *ec;
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int sensor_num;
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struct cros_ec_command *msg;
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struct ec_params_motion_sense *params;
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struct ec_response_motion_sense *resp;
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struct mutex cmd_lock; /* Lock for protecting msg structure. */
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struct notifier_block notifier;
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struct cros_ec_sensors_ring_sample *ring;
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ktime_t fifo_timestamp[CROS_EC_SENSOR_ALL_TS];
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struct ec_response_motion_sense_fifo_info *fifo_info;
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int fifo_size;
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struct cros_ec_sensors_ts_batch_state *batch_state;
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struct cros_ec_sensors_ec_overflow_state overflow_a;
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struct cros_ec_sensors_ec_overflow_state overflow_b;
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struct cros_ec_sensors_ts_filter_state filter;
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int tight_timestamps;
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s32 future_timestamp_count;
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s64 future_timestamp_total_ns;
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struct cros_ec_sensorhub_sensor_push_data *push_data;
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};
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int cros_ec_sensorhub_register_push_data(struct cros_ec_sensorhub *sensorhub,
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u8 sensor_num,
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struct iio_dev *indio_dev,
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cros_ec_sensorhub_push_data_cb_t cb);
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void cros_ec_sensorhub_unregister_push_data(struct cros_ec_sensorhub *sensorhub,
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u8 sensor_num);
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int cros_ec_sensorhub_ring_allocate(struct cros_ec_sensorhub *sensorhub);
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int cros_ec_sensorhub_ring_add(struct cros_ec_sensorhub *sensorhub);
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void cros_ec_sensorhub_ring_remove(void *arg);
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int cros_ec_sensorhub_ring_fifo_enable(struct cros_ec_sensorhub *sensorhub,
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bool on);
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#endif /* __LINUX_PLATFORM_DATA_CROS_EC_SENSORHUB_H */
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