root/include/linux/hid-sensor-hub.h
/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * HID Sensors Driver
 * Copyright (c) 2012, Intel Corporation.
 */
#ifndef _HID_SENSORS_HUB_H
#define _HID_SENSORS_HUB_H

#include <linux/hid.h>
#include <linux/hid-sensor-ids.h>
#include <linux/iio/iio.h>
#include <linux/iio/trigger.h>

/**
 * struct hid_sensor_hub_attribute_info - Attribute info
 * @usage_id:           Parent usage id of a physical device.
 * @attrib_id:          Attribute id for this attribute.
 * @report_id:          Report id in which this information resides.
 * @index:              Field index in the report.
 * @units:              Measurement unit for this attribute.
 * @unit_expo:          Exponent used in the data.
 * @size:               Size in bytes for data size.
 * @logical_minimum:    Logical minimum value for this attribute.
 * @logical_maximum:    Logical maximum value for this attribute.
 */
struct hid_sensor_hub_attribute_info {
        u32 usage_id;
        u32 attrib_id;
        s32 report_id;
        s32 index;
        s32 units;
        s32 unit_expo;
        s32 size;
        s32 logical_minimum;
        s32 logical_maximum;
};

/**
 * struct sensor_hub_pending - Synchronous read pending information
 * @status:             Pending status true/false.
 * @ready:              Completion synchronization data.
 * @usage_id:           Usage id for physical device, e.g. gyro usage id.
 * @attr_usage_id:      Usage Id of a field, e.g. X-axis for a gyro.
 * @raw_size:           Response size for a read request.
 * @raw_data:           Place holder for received response.
 */
struct sensor_hub_pending {
        bool status;
        struct completion ready;
        u32 usage_id;
        u32 attr_usage_id;
        int raw_size;
        u8  *raw_data;
};

/**
 * struct hid_sensor_hub_device - Stores the hub instance data
 * @hdev:               Stores the hid instance.
 * @vendor_id:          Vendor id of hub device.
 * @product_id:         Product id of hub device.
 * @usage:              Usage id for this hub device instance.
 * @start_collection_index: Starting index for a phy type collection
 * @end_collection_index: Last index for a phy type collection
 * @mutex_ptr:          synchronizing mutex pointer.
 * @pending:            Holds information of pending sync read request.
 */
struct hid_sensor_hub_device {
        struct hid_device *hdev;
        u32 vendor_id;
        u32 product_id;
        u32 usage;
        int start_collection_index;
        int end_collection_index;
        struct mutex *mutex_ptr;
        struct sensor_hub_pending pending;
};

/**
 * struct hid_sensor_hub_callbacks - Client callback functions
 * @pdev:               Platform device instance of the client driver.
 * @suspend:            Suspend callback.
 * @resume:             Resume callback.
 * @capture_sample:     Callback to get a sample.
 * @send_event:         Send notification to indicate all samples are
 *                      captured, process and send event
 */
struct hid_sensor_hub_callbacks {
        struct platform_device *pdev;
        int (*suspend)(struct hid_sensor_hub_device *hsdev, void *priv);
        int (*resume)(struct hid_sensor_hub_device *hsdev, void *priv);
        int (*capture_sample)(struct hid_sensor_hub_device *hsdev,
                        u32 usage_id, size_t raw_len, char *raw_data,
                        void *priv);
        int (*send_event)(struct hid_sensor_hub_device *hsdev, u32 usage_id,
                         void *priv);
};

/**
* sensor_hub_device_open() - Open hub device
* @hsdev:       Hub device instance.
*
* Used to open hid device for sensor hub.
*/
int sensor_hub_device_open(struct hid_sensor_hub_device *hsdev);

/**
* sensor_hub_device_close() - Close hub device
* @hsdev:       Hub device instance.
*
* Used to close hid device for sensor hub.
*/
void sensor_hub_device_close(struct hid_sensor_hub_device *hsdev);

/* Registration functions */

/**
* sensor_hub_register_callback() - Register client callbacks
* @hsdev:       Hub device instance.
* @usage_id:    Usage id of the client (E.g. 0x200076 for Gyro).
* @usage_callback: Callback function storage
*
* Used to register callbacks by client processing drivers. Sensor
* hub core driver will call these callbacks to offload processing
* of data streams and notifications.
*/
int sensor_hub_register_callback(struct hid_sensor_hub_device *hsdev,
                        u32 usage_id,
                        struct hid_sensor_hub_callbacks *usage_callback);

/**
* sensor_hub_remove_callback() - Remove client callback
* @hsdev:       Hub device instance.
* @usage_id:    Usage id of the client (e.g. 0x200076 for gyro).
*
* Removes a previously registered callback for the given usage_id
* and hsdev. Once removed, the client will no longer receive data or
* event notifications.
*/
int sensor_hub_remove_callback(struct hid_sensor_hub_device *hsdev,
                        u32 usage_id);


/* Hid sensor hub core interfaces */

/**
* sensor_hub_input_get_attribute_info() - Get an attribute information
* @hsdev:       Hub device instance.
* @type:        Type of this attribute, input/output/feature
* @usage_id:    Attribute usage id of parent physical device as per spec
* @attr_usage_id:       Attribute usage id as per spec
* @info:        return information about attribute after parsing report
*
* Parses report and returns the attribute information such as report id,
* field index, units and exponent etc.
*/
int sensor_hub_input_get_attribute_info(struct hid_sensor_hub_device *hsdev,
                        u8 type,
                        u32 usage_id, u32 attr_usage_id,
                        struct hid_sensor_hub_attribute_info *info);

/**
* sensor_hub_input_attr_get_raw_value() - Synchronous read request
* @hsdev:       Hub device instance.
* @usage_id:    Attribute usage id of parent physical device as per spec
* @attr_usage_id:       Attribute usage id as per spec
* @report_id:   Report id to look for
* @flag:      Synchronous or asynchronous read
* @is_signed:   If true then fields < 32 bits will be sign-extended
*
* Issues a synchronous or asynchronous read request for an input attribute.
* Return: data up to 32 bits.
*/

enum sensor_hub_read_flags {
        SENSOR_HUB_SYNC,
        SENSOR_HUB_ASYNC,
};

int sensor_hub_input_attr_get_raw_value(struct hid_sensor_hub_device *hsdev,
                                        u32 usage_id,
                                        u32 attr_usage_id, u32 report_id,
                                        enum sensor_hub_read_flags flag,
                                        bool is_signed
);

/**
* sensor_hub_set_feature() - Feature set request
* @hsdev:       Hub device instance.
* @report_id:   Report id to look for
* @field_index: Field index inside a report
* @buffer_size: size of the buffer
* @buffer:      buffer to use in the feature set
*
* Used to set a field in feature report. For example this can set polling
* interval, sensitivity, activate/deactivate state.
*/
int sensor_hub_set_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
                           u32 field_index, int buffer_size, void *buffer);

/**
* sensor_hub_get_feature() - Feature get request
* @hsdev:       Hub device instance.
* @report_id:   Report id to look for
* @field_index: Field index inside a report
* @buffer_size: size of the buffer
* @buffer:      buffer to copy output
*
* Used to get a field in feature report. For example this can get polling
* interval, sensitivity, activate/deactivate state.
* Return: On success, it returns the number of bytes copied to buffer.
* On failure, it returns value < 0.
*/
int sensor_hub_get_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
                           u32 field_index, int buffer_size, void *buffer);

/* hid-sensor-attributes */

/* Common hid sensor iio structure */
struct hid_sensor_common {
        struct hid_sensor_hub_device *hsdev;
        struct platform_device *pdev;
        unsigned usage_id;
        atomic_t data_ready;
        atomic_t user_requested_state;
        atomic_t runtime_pm_enable;
        int poll_interval;
        int raw_hystersis;
        int latency_ms;
        struct iio_trigger *trigger;
        int timestamp_ns_scale;
        struct hid_sensor_hub_attribute_info poll;
        struct hid_sensor_hub_attribute_info report_state;
        struct hid_sensor_hub_attribute_info power_state;
        struct hid_sensor_hub_attribute_info sensitivity;
        struct hid_sensor_hub_attribute_info sensitivity_rel;
        struct hid_sensor_hub_attribute_info report_latency;
        struct work_struct work;
};

/* Convert from hid unit expo to regular exponent */
static inline int hid_sensor_convert_exponent(int unit_expo)
{
        if (unit_expo < 0x08)
                return unit_expo;
        else if (unit_expo <= 0x0f)
                return -(0x0f-unit_expo+1);
        else
                return 0;
}

int hid_sensor_parse_common_attributes(struct hid_sensor_hub_device *hsdev,
                                        u32 usage_id,
                                        struct hid_sensor_common *st,
                                        const u32 *sensitivity_addresses,
                                        u32 sensitivity_addresses_len);
int hid_sensor_write_raw_hyst_value(struct hid_sensor_common *st,
                                        int val1, int val2);
int hid_sensor_write_raw_hyst_rel_value(struct hid_sensor_common *st, int val1,
                                        int val2);
int hid_sensor_read_raw_hyst_value(struct hid_sensor_common *st,
                                        int *val1, int *val2);
int hid_sensor_read_raw_hyst_rel_value(struct hid_sensor_common *st,
                                       int *val1, int *val2);
int hid_sensor_write_samp_freq_value(struct hid_sensor_common *st,
                                        int val1, int val2);
int hid_sensor_read_samp_freq_value(struct hid_sensor_common *st,
                                        int *val1, int *val2);

int hid_sensor_get_usage_index(struct hid_sensor_hub_device *hsdev,
                                u32 report_id, int field_index, u32 usage_id);

int hid_sensor_format_scale(u32 usage_id,
                            struct hid_sensor_hub_attribute_info *attr_info,
                            int *val0, int *val1);

s32 hid_sensor_read_poll_value(struct hid_sensor_common *st);

int64_t hid_sensor_convert_timestamp(struct hid_sensor_common *st,
                                     int64_t raw_value);
bool hid_sensor_batch_mode_supported(struct hid_sensor_common *st);
int hid_sensor_set_report_latency(struct hid_sensor_common *st, int latency);
int hid_sensor_get_report_latency(struct hid_sensor_common *st);

#endif