/*
* ChromeOS EC sensor hub
*
* Copyright (C) 2016 Google, Inc
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#ifndef __CROS_EC_SENSORS_CORE_H
#define __CROS_EC_SENSORS_CORE_H
#include <linux/iio/iio.h>
#include <linux/irqreturn.h>
#include <linux/mfd/cros_ec.h>
enum {
CROS_EC_SENSOR_X,
CROS_EC_SENSOR_Y,
CROS_EC_SENSOR_Z,
CROS_EC_SENSOR_MAX_AXIS,
};
/* EC returns sensor values using signed 16 bit registers */
#define CROS_EC_SENSOR_BITS 16
/*
* 4 16 bit channels are allowed.
* Good enough for current sensors, they use up to 3 16 bit vectors.
*/
#define CROS_EC_SAMPLE_SIZE (sizeof(s64) * 2)
/* Minimum sampling period to use when device is suspending */
#define CROS_EC_MIN_SUSPEND_SAMPLING_FREQUENCY 1000 /* 1 second */
/**
* struct cros_ec_sensors_core_state - state data for EC sensors IIO driver
* @ec: cros EC device structure
* @cmd_lock: lock used to prevent simultaneous access to the
* commands.
* @msg: cros EC command structure
* @param: motion sensor parameters structure
* @resp: motion sensor response structure
* @type: type of motion sensor
* @loc: location where the motion sensor is placed
* @calib: calibration parameters. Note that trigger
* captured data will always provide the calibrated
* data
* @samples: static array to hold data from a single capture.
* For each channel we need 2 bytes, except for
* the timestamp. The timestamp is always last and
* is always 8-byte aligned.
* @read_ec_sensors_data: function used for accessing sensors values
* @cuur_sampl_freq: current sampling period
*/
struct cros_ec_sensors_core_state {
struct cros_ec_device *ec;
struct mutex cmd_lock;
struct cros_ec_command *msg;
struct ec_params_motion_sense param;
struct ec_response_motion_sense *resp;
enum motionsensor_type type;
enum motionsensor_location loc;
s16 calib[CROS_EC_SENSOR_MAX_AXIS];
u8 samples[CROS_EC_SAMPLE_SIZE];
int (*read_ec_sensors_data)(struct iio_dev *indio_dev,
unsigned long scan_mask, s16 *data);
int curr_sampl_freq;
};
/**
* cros_ec_sensors_read_lpc() - retrieve data from EC shared memory
* @indio_dev: pointer to IIO device
* @scan_mask: bitmap of the sensor indices to scan
* @data: location to store data
*
* This is the safe function for reading the EC data. It guarantees that the
* data sampled was not modified by the EC while being read.
*
* Return: 0 on success, -errno on failure.
*/
int cros_ec_sensors_read_lpc(struct iio_dev *indio_dev, unsigned long scan_mask,
s16 *data);
/**
* cros_ec_sensors_read_cmd() - retrieve data using the EC command protocol
* @indio_dev: pointer to IIO device
* @scan_mask: bitmap of the sensor indices to scan
* @data: location to store data
*
* Return: 0 on success, -errno on failure.
*/
int cros_ec_sensors_read_cmd(struct iio_dev *indio_dev, unsigned long scan_mask,
s16 *data);
struct platform_device;
/**
* cros_ec_sensors_core_init() - basic initialization of the core structure
* @pdev: platform device created for the sensors
* @indio_dev: iio device structure of the device
* @physical_device: true if the device refers to a physical device
*
* Return: 0 on success, -errno on failure.
*/
int cros_ec_sensors_core_init(struct platform_device *pdev,
struct iio_dev *indio_dev, bool physical_device);
/**
* cros_ec_sensors_capture() - the trigger handler function
* @irq: the interrupt number.
* @p: a pointer to the poll function.
*
* On a trigger event occurring, if the pollfunc is attached then this
* handler is called as a threaded interrupt (and hence may sleep). It
* is responsible for grabbing data from the device and pushing it into
* the associated buffer.
*
* Return: IRQ_HANDLED
*/
irqreturn_t cros_ec_sensors_capture(int irq, void *p);
/**
* cros_ec_motion_send_host_cmd() - send motion sense host command
* @st: pointer to state information for device
* @opt_length: optional length to reduce the response size, useful on the data
* path. Otherwise, the maximal allowed response size is used
*
* When called, the sub-command is assumed to be set in param->cmd.
*
* Return: 0 on success, -errno on failure.
*/
int cros_ec_motion_send_host_cmd(struct cros_ec_sensors_core_state *st,
u16 opt_length);
/**
* cros_ec_sensors_core_read() - function to request a value from the sensor
* @st: pointer to state information for device
* @chan: channel specification structure table
* @val: will contain one element making up the returned value
* @val2: will contain another element making up the returned value
* @mask: specifies which values to be requested
*
* Return: the type of value returned by the device
*/
int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask);
/**
* cros_ec_sensors_core_write() - function to write a value to the sensor
* @st: pointer to state information for device
* @chan: channel specification structure table
* @val: first part of value to write
* @val2: second part of value to write
* @mask: specifies which values to write
*
* Return: the type of value returned by the device
*/
int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
struct iio_chan_spec const *chan,
int val, int val2, long mask);
extern const struct dev_pm_ops cros_ec_sensors_pm_ops;
/* List of extended channel specification for all sensors */
extern const struct iio_chan_spec_ext_info cros_ec_sensors_ext_info[];
#endif /* __CROS_EC_SENSORS_CORE_H */
