1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * ChromeOS EC sensor hub 4 * 5 * Copyright (C) 2016 Google, Inc 6 */ 7 8 #ifndef __CROS_EC_SENSORS_CORE_H 9 #define __CROS_EC_SENSORS_CORE_H 10 11 #include <linux/iio/iio.h> 12 #include <linux/irqreturn.h> 13 #include <linux/platform_data/cros_ec_commands.h> 14 #include <linux/platform_data/cros_ec_proto.h> 15 16 enum { 17 CROS_EC_SENSOR_X, 18 CROS_EC_SENSOR_Y, 19 CROS_EC_SENSOR_Z, 20 CROS_EC_SENSOR_MAX_AXIS, 21 }; 22 23 /* EC returns sensor values using signed 16 bit registers */ 24 #define CROS_EC_SENSOR_BITS 16 25 26 /* 27 * 4 16 bit channels are allowed. 28 * Good enough for current sensors, they use up to 3 16 bit vectors. 29 */ 30 #define CROS_EC_SAMPLE_SIZE (sizeof(s64) * 2) 31 32 /* Minimum sampling period to use when device is suspending */ 33 #define CROS_EC_MIN_SUSPEND_SAMPLING_FREQUENCY 1000 /* 1 second */ 34 35 /** 36 * struct cros_ec_sensors_core_state - state data for EC sensors IIO driver 37 * @ec: cros EC device structure 38 * @cmd_lock: lock used to prevent simultaneous access to the 39 * commands. 40 * @msg: cros EC command structure 41 * @param: motion sensor parameters structure 42 * @resp: motion sensor response structure 43 * @type: type of motion sensor 44 * @loc: location where the motion sensor is placed 45 * @calib: calibration parameters. Note that trigger 46 * captured data will always provide the calibrated 47 * data 48 * @samples: static array to hold data from a single capture. 49 * For each channel we need 2 bytes, except for 50 * the timestamp. The timestamp is always last and 51 * is always 8-byte aligned. 52 * @read_ec_sensors_data: function used for accessing sensors values 53 * @cuur_sampl_freq: current sampling period 54 */ 55 struct cros_ec_sensors_core_state { 56 struct cros_ec_device *ec; 57 struct mutex cmd_lock; 58 59 struct cros_ec_command *msg; 60 struct ec_params_motion_sense param; 61 struct ec_response_motion_sense *resp; 62 63 enum motionsensor_type type; 64 enum motionsensor_location loc; 65 66 struct calib_data { 67 s16 offset; 68 u16 scale; 69 } calib[CROS_EC_SENSOR_MAX_AXIS]; 70 s8 sign[CROS_EC_SENSOR_MAX_AXIS]; 71 u8 samples[CROS_EC_SAMPLE_SIZE]; 72 73 int (*read_ec_sensors_data)(struct iio_dev *indio_dev, 74 unsigned long scan_mask, s16 *data); 75 76 int curr_sampl_freq; 77 78 /* Table of known available frequencies : 0, Min and Max in mHz */ 79 int frequencies[3]; 80 }; 81 82 /** 83 * cros_ec_sensors_read_lpc() - retrieve data from EC shared memory 84 * @indio_dev: pointer to IIO device 85 * @scan_mask: bitmap of the sensor indices to scan 86 * @data: location to store data 87 * 88 * This is the safe function for reading the EC data. It guarantees that the 89 * data sampled was not modified by the EC while being read. 90 * 91 * Return: 0 on success, -errno on failure. 92 */ 93 int cros_ec_sensors_read_lpc(struct iio_dev *indio_dev, unsigned long scan_mask, 94 s16 *data); 95 96 /** 97 * cros_ec_sensors_read_cmd() - retrieve data using the EC command protocol 98 * @indio_dev: pointer to IIO device 99 * @scan_mask: bitmap of the sensor indices to scan 100 * @data: location to store data 101 * 102 * Return: 0 on success, -errno on failure. 103 */ 104 int cros_ec_sensors_read_cmd(struct iio_dev *indio_dev, unsigned long scan_mask, 105 s16 *data); 106 107 struct platform_device; 108 /** 109 * cros_ec_sensors_core_init() - basic initialization of the core structure 110 * @pdev: platform device created for the sensors 111 * @indio_dev: iio device structure of the device 112 * @physical_device: true if the device refers to a physical device 113 * 114 * Return: 0 on success, -errno on failure. 115 */ 116 int cros_ec_sensors_core_init(struct platform_device *pdev, 117 struct iio_dev *indio_dev, bool physical_device); 118 119 /** 120 * cros_ec_sensors_capture() - the trigger handler function 121 * @irq: the interrupt number. 122 * @p: a pointer to the poll function. 123 * 124 * On a trigger event occurring, if the pollfunc is attached then this 125 * handler is called as a threaded interrupt (and hence may sleep). It 126 * is responsible for grabbing data from the device and pushing it into 127 * the associated buffer. 128 * 129 * Return: IRQ_HANDLED 130 */ 131 irqreturn_t cros_ec_sensors_capture(int irq, void *p); 132 133 /** 134 * cros_ec_motion_send_host_cmd() - send motion sense host command 135 * @st: pointer to state information for device 136 * @opt_length: optional length to reduce the response size, useful on the data 137 * path. Otherwise, the maximal allowed response size is used 138 * 139 * When called, the sub-command is assumed to be set in param->cmd. 140 * 141 * Return: 0 on success, -errno on failure. 142 */ 143 int cros_ec_motion_send_host_cmd(struct cros_ec_sensors_core_state *st, 144 u16 opt_length); 145 146 /** 147 * cros_ec_sensors_core_read() - function to request a value from the sensor 148 * @st: pointer to state information for device 149 * @chan: channel specification structure table 150 * @val: will contain one element making up the returned value 151 * @val2: will contain another element making up the returned value 152 * @mask: specifies which values to be requested 153 * 154 * Return: the type of value returned by the device 155 */ 156 int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st, 157 struct iio_chan_spec const *chan, 158 int *val, int *val2, long mask); 159 160 /** 161 * cros_ec_sensors_core_read_avail() - get available values 162 * @indio_dev: pointer to state information for device 163 * @chan: channel specification structure table 164 * @vals: list of available values 165 * @type: type of data returned 166 * @length: number of data returned in the array 167 * @mask: specifies which values to be requested 168 * 169 * Return: an error code, IIO_AVAIL_RANGE or IIO_AVAIL_LIST 170 */ 171 int cros_ec_sensors_core_read_avail(struct iio_dev *indio_dev, 172 struct iio_chan_spec const *chan, 173 const int **vals, 174 int *type, 175 int *length, 176 long mask); 177 178 /** 179 * cros_ec_sensors_core_write() - function to write a value to the sensor 180 * @st: pointer to state information for device 181 * @chan: channel specification structure table 182 * @val: first part of value to write 183 * @val2: second part of value to write 184 * @mask: specifies which values to write 185 * 186 * Return: the type of value returned by the device 187 */ 188 int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st, 189 struct iio_chan_spec const *chan, 190 int val, int val2, long mask); 191 192 extern const struct dev_pm_ops cros_ec_sensors_pm_ops; 193 194 /* List of extended channel specification for all sensors */ 195 extern const struct iio_chan_spec_ext_info cros_ec_sensors_ext_info[]; 196 197 #endif /* __CROS_EC_SENSORS_CORE_H */ 198