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 | |