1 /* 2 * ChromeOS EC sensor hub 3 * 4 * Copyright (C) 2016 Google, Inc 5 * 6 * This software is licensed under the terms of the GNU General Public 7 * License version 2, as published by the Free Software Foundation, and 8 * may be copied, distributed, and modified under those terms. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 */ 15 16 #ifndef __CROS_EC_SENSORS_CORE_H 17 #define __CROS_EC_SENSORS_CORE_H 18 19 #include <linux/iio/iio.h> 20 #include <linux/irqreturn.h> 21 #include <linux/mfd/cros_ec.h> 22 23 enum { 24 CROS_EC_SENSOR_X, 25 CROS_EC_SENSOR_Y, 26 CROS_EC_SENSOR_Z, 27 CROS_EC_SENSOR_MAX_AXIS, 28 }; 29 30 /* EC returns sensor values using signed 16 bit registers */ 31 #define CROS_EC_SENSOR_BITS 16 32 33 /* 34 * 4 16 bit channels are allowed. 35 * Good enough for current sensors, they use up to 3 16 bit vectors. 36 */ 37 #define CROS_EC_SAMPLE_SIZE (sizeof(s64) * 2) 38 39 /* Minimum sampling period to use when device is suspending */ 40 #define CROS_EC_MIN_SUSPEND_SAMPLING_FREQUENCY 1000 /* 1 second */ 41 42 /** 43 * struct cros_ec_sensors_core_state - state data for EC sensors IIO driver 44 * @ec: cros EC device structure 45 * @cmd_lock: lock used to prevent simultaneous access to the 46 * commands. 47 * @msg: cros EC command structure 48 * @param: motion sensor parameters structure 49 * @resp: motion sensor response structure 50 * @type: type of motion sensor 51 * @loc: location where the motion sensor is placed 52 * @calib: calibration parameters. Note that trigger 53 * captured data will always provide the calibrated 54 * data 55 * @samples: static array to hold data from a single capture. 56 * For each channel we need 2 bytes, except for 57 * the timestamp. The timestamp is always last and 58 * is always 8-byte aligned. 59 * @read_ec_sensors_data: function used for accessing sensors values 60 * @cuur_sampl_freq: current sampling period 61 */ 62 struct cros_ec_sensors_core_state { 63 struct cros_ec_device *ec; 64 struct mutex cmd_lock; 65 66 struct cros_ec_command *msg; 67 struct ec_params_motion_sense param; 68 struct ec_response_motion_sense *resp; 69 70 enum motionsensor_type type; 71 enum motionsensor_location loc; 72 73 s16 calib[CROS_EC_SENSOR_MAX_AXIS]; 74 75 u8 samples[CROS_EC_SAMPLE_SIZE]; 76 77 int (*read_ec_sensors_data)(struct iio_dev *indio_dev, 78 unsigned long scan_mask, s16 *data); 79 80 int curr_sampl_freq; 81 }; 82 83 /** 84 * cros_ec_sensors_read_lpc() - retrieve data from EC shared memory 85 * @indio_dev: pointer to IIO device 86 * @scan_mask: bitmap of the sensor indices to scan 87 * @data: location to store data 88 * 89 * This is the safe function for reading the EC data. It guarantees that the 90 * data sampled was not modified by the EC while being read. 91 * 92 * Return: 0 on success, -errno on failure. 93 */ 94 int cros_ec_sensors_read_lpc(struct iio_dev *indio_dev, unsigned long scan_mask, 95 s16 *data); 96 97 /** 98 * cros_ec_sensors_read_cmd() - retrieve data using the EC command protocol 99 * @indio_dev: pointer to IIO device 100 * @scan_mask: bitmap of the sensor indices to scan 101 * @data: location to store data 102 * 103 * Return: 0 on success, -errno on failure. 104 */ 105 int cros_ec_sensors_read_cmd(struct iio_dev *indio_dev, unsigned long scan_mask, 106 s16 *data); 107 108 struct platform_device; 109 /** 110 * cros_ec_sensors_core_init() - basic initialization of the core structure 111 * @pdev: platform device created for the sensors 112 * @indio_dev: iio device structure of the device 113 * @physical_device: true if the device refers to a physical device 114 * 115 * Return: 0 on success, -errno on failure. 116 */ 117 int cros_ec_sensors_core_init(struct platform_device *pdev, 118 struct iio_dev *indio_dev, bool physical_device); 119 120 /** 121 * cros_ec_sensors_capture() - the trigger handler function 122 * @irq: the interrupt number. 123 * @p: a pointer to the poll function. 124 * 125 * On a trigger event occurring, if the pollfunc is attached then this 126 * handler is called as a threaded interrupt (and hence may sleep). It 127 * is responsible for grabbing data from the device and pushing it into 128 * the associated buffer. 129 * 130 * Return: IRQ_HANDLED 131 */ 132 irqreturn_t cros_ec_sensors_capture(int irq, void *p); 133 134 /** 135 * cros_ec_motion_send_host_cmd() - send motion sense host command 136 * @st: pointer to state information for device 137 * @opt_length: optional length to reduce the response size, useful on the data 138 * path. Otherwise, the maximal allowed response size is used 139 * 140 * When called, the sub-command is assumed to be set in param->cmd. 141 * 142 * Return: 0 on success, -errno on failure. 143 */ 144 int cros_ec_motion_send_host_cmd(struct cros_ec_sensors_core_state *st, 145 u16 opt_length); 146 147 /** 148 * cros_ec_sensors_core_read() - function to request a value from the sensor 149 * @st: pointer to state information for device 150 * @chan: channel specification structure table 151 * @val: will contain one element making up the returned value 152 * @val2: will contain another element making up the returned value 153 * @mask: specifies which values to be requested 154 * 155 * Return: the type of value returned by the device 156 */ 157 int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st, 158 struct iio_chan_spec const *chan, 159 int *val, int *val2, long mask); 160 161 /** 162 * cros_ec_sensors_core_write() - function to write a value to the sensor 163 * @st: pointer to state information for device 164 * @chan: channel specification structure table 165 * @val: first part of value to write 166 * @val2: second part of value to write 167 * @mask: specifies which values to write 168 * 169 * Return: the type of value returned by the device 170 */ 171 int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st, 172 struct iio_chan_spec const *chan, 173 int val, int val2, long mask); 174 175 extern const struct dev_pm_ops cros_ec_sensors_pm_ops; 176 177 /* List of extended channel specification for all sensors */ 178 extern const struct iio_chan_spec_ext_info cros_ec_sensors_ext_info[]; 179 180 #endif /* __CROS_EC_SENSORS_CORE_H */ 181
