1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Chrome OS EC MEMS Sensor Hub driver. 4 * 5 * Copyright 2019 Google LLC 6 */ 7 8 #ifndef __LINUX_PLATFORM_DATA_CROS_EC_SENSORHUB_H 9 #define __LINUX_PLATFORM_DATA_CROS_EC_SENSORHUB_H 10 11 #include <linux/ktime.h> 12 #include <linux/mutex.h> 13 #include <linux/notifier.h> 14 #include <linux/platform_data/cros_ec_commands.h> 15 16 struct iio_dev; 17 18 /** 19 * struct cros_ec_sensor_platform - ChromeOS EC sensor platform information. 20 * @sensor_num: Id of the sensor, as reported by the EC. 21 */ 22 struct cros_ec_sensor_platform { 23 u8 sensor_num; 24 }; 25 26 /** 27 * typedef cros_ec_sensorhub_push_data_cb_t - Callback function to send datum 28 * to specific sensors. 29 * 30 * @indio_dev: The IIO device that will process the sample. 31 * @data: Vector array of the ring sample. 32 * @timestamp: Timestamp in host timespace when the sample was acquired by 33 * the EC. 34 */ 35 typedef int (*cros_ec_sensorhub_push_data_cb_t)(struct iio_dev *indio_dev, 36 s16 *data, 37 s64 timestamp); 38 39 struct cros_ec_sensorhub_sensor_push_data { 40 struct iio_dev *indio_dev; 41 cros_ec_sensorhub_push_data_cb_t push_data_cb; 42 }; 43 44 enum { 45 CROS_EC_SENSOR_LAST_TS, 46 CROS_EC_SENSOR_NEW_TS, 47 CROS_EC_SENSOR_ALL_TS 48 }; 49 50 struct cros_ec_sensors_ring_sample { 51 u8 sensor_id; 52 u8 flag; 53 s16 vector[3]; 54 s64 timestamp; 55 } __packed; 56 57 /* State used for cros_ec_ring_fix_overflow */ 58 struct cros_ec_sensors_ec_overflow_state { 59 s64 offset; 60 s64 last; 61 }; 62 63 /* Length of the filter, how long to remember entries for */ 64 #define CROS_EC_SENSORHUB_TS_HISTORY_SIZE 64 65 66 /** 67 * struct cros_ec_sensors_ts_filter_state - Timestamp filetr state. 68 * 69 * @x_offset: x is EC interrupt time. x_offset its last value. 70 * @y_offset: y is the difference between AP and EC time, y_offset its last 71 * value. 72 * @x_history: The past history of x, relative to x_offset. 73 * @y_history: The past history of y, relative to y_offset. 74 * @m_history: rate between y and x. 75 * @history_len: Amount of valid historic data in the arrays. 76 * @temp_buf: Temporary buffer used when updating the filter. 77 * @median_m: median value of m_history 78 * @median_error: final error to apply to AP interrupt timestamp to get the 79 * "true timestamp" the event occurred. 80 */ 81 struct cros_ec_sensors_ts_filter_state { 82 s64 x_offset, y_offset; 83 s64 x_history[CROS_EC_SENSORHUB_TS_HISTORY_SIZE]; 84 s64 y_history[CROS_EC_SENSORHUB_TS_HISTORY_SIZE]; 85 s64 m_history[CROS_EC_SENSORHUB_TS_HISTORY_SIZE]; 86 int history_len; 87 88 s64 temp_buf[CROS_EC_SENSORHUB_TS_HISTORY_SIZE]; 89 90 s64 median_m; 91 s64 median_error; 92 }; 93 94 /* struct cros_ec_sensors_ts_batch_state - State of batch of a single sensor. 95 * 96 * Use to store information to batch data using median fileter information. 97 * 98 * @penul_ts: last but one batch timestamp (penultimate timestamp). 99 * Used for timestamp spreading calculations 100 * when a batch shows up. 101 * @penul_len: last but one batch length. 102 * @last_ts: Last batch timestam. 103 * @last_len: Last batch length. 104 * @newest_sensor_event: Last sensor timestamp. 105 */ 106 struct cros_ec_sensors_ts_batch_state { 107 s64 penul_ts; 108 int penul_len; 109 s64 last_ts; 110 int last_len; 111 s64 newest_sensor_event; 112 }; 113 114 /* 115 * struct cros_ec_sensorhub - Sensor Hub device data. 116 * 117 * @dev: Device object, mostly used for logging. 118 * @ec: Embedded Controller where the hub is located. 119 * @sensor_num: Number of MEMS sensors present in the EC. 120 * @msg: Structure to send FIFO requests. 121 * @params: Pointer to parameters in msg. 122 * @resp: Pointer to responses in msg. 123 * @cmd_lock : Lock for sending msg. 124 * @notifier: Notifier to kick the FIFO interrupt. 125 * @ring: Preprocessed ring to store events. 126 * @fifo_timestamp: Array for event timestamp and spreading. 127 * @fifo_info: Copy of FIFO information coming from the EC. 128 * @fifo_size: Size of the ring. 129 * @batch_state: Per sensor information of the last batches received. 130 * @overflow_a: For handling timestamp overflow for a time (sensor events) 131 * @overflow_b: For handling timestamp overflow for b time (ec interrupts) 132 * @filter: Medium fileter structure. 133 * @tight_timestamps: Set to truen when EC support tight timestamping: 134 * The timestamps reported from the EC have low jitter. 135 * Timestamps also come before every sample. Set either 136 * by feature bits coming from the EC or userspace. 137 * @future_timestamp_count: Statistics used to compute shaved time. 138 * This occurs when timestamp interpolation from EC 139 * time to AP time accidentally puts timestamps in 140 * the future. These timestamps are clamped to 141 * `now` and these count/total_ns maintain the 142 * statistics for how much time was removed in a 143 * given period. 144 * @future_timestamp_total_ns: Total amount of time shaved. 145 * @push_data: Array of callback to send datums to iio sensor object. 146 */ 147 struct cros_ec_sensorhub { 148 struct device *dev; 149 struct cros_ec_dev *ec; 150 int sensor_num; 151 152 struct cros_ec_command *msg; 153 struct ec_params_motion_sense *params; 154 struct ec_response_motion_sense *resp; 155 struct mutex cmd_lock; /* Lock for protecting msg structure. */ 156 157 struct notifier_block notifier; 158 159 struct cros_ec_sensors_ring_sample *ring; 160 161 ktime_t fifo_timestamp[CROS_EC_SENSOR_ALL_TS]; 162 struct ec_response_motion_sense_fifo_info *fifo_info; 163 int fifo_size; 164 165 struct cros_ec_sensors_ts_batch_state *batch_state; 166 167 struct cros_ec_sensors_ec_overflow_state overflow_a; 168 struct cros_ec_sensors_ec_overflow_state overflow_b; 169 170 struct cros_ec_sensors_ts_filter_state filter; 171 172 int tight_timestamps; 173 174 s32 future_timestamp_count; 175 s64 future_timestamp_total_ns; 176 177 struct cros_ec_sensorhub_sensor_push_data *push_data; 178 }; 179 180 int cros_ec_sensorhub_register_push_data(struct cros_ec_sensorhub *sensorhub, 181 u8 sensor_num, 182 struct iio_dev *indio_dev, 183 cros_ec_sensorhub_push_data_cb_t cb); 184 185 void cros_ec_sensorhub_unregister_push_data(struct cros_ec_sensorhub *sensorhub, 186 u8 sensor_num); 187 188 int cros_ec_sensorhub_ring_allocate(struct cros_ec_sensorhub *sensorhub); 189 int cros_ec_sensorhub_ring_add(struct cros_ec_sensorhub *sensorhub); 190 void cros_ec_sensorhub_ring_remove(void *arg); 191 int cros_ec_sensorhub_ring_fifo_enable(struct cros_ec_sensorhub *sensorhub, 192 bool on); 193 194 #endif /* __LINUX_PLATFORM_DATA_CROS_EC_SENSORHUB_H */ 195