Distribute under Apache License v2.0

[android-x86/hardware-intel-libsensors.git] / common.h

/*
// Copyright (c) 2015 Intel Corporation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
*/

#ifndef __COMMON_H__
#define __COMMON_H__

#define MAX_DEVICES     9       /* Check iio devices 0 to MAX_DEVICES-1 */
#define MAX_SENSORS     12      /* We can handle as many sensors */
#define MAX_CHANNELS    4       /* We can handle as many channels per sensor */
#define MAX_EVENTS      2       /* We can handle as many events per channel */
#define MAX_TRIGGERS    8       /* Check for triggers 0 to MAX_TRIGGERS-1 */

#define DEV_FILE_PATH           "/dev/iio:device%d"
#define BASE_PATH               "/sys/bus/iio/devices/iio:device%d/"
#define TRIGGER_FILE_PATH       "/sys/bus/iio/devices/trigger%d/name"
#define IIO_DEVICES             "/sys/bus/iio/devices/"

#define CHANNEL_PATH            BASE_PATH "scan_elements/"
#define ENABLE_PATH             BASE_PATH "buffer/enable"
#define BUFFER_LENGTH_PATH      BASE_PATH "buffer/length"
#define NAME_PATH               BASE_PATH "name"
#define TRIGGER_PATH            BASE_PATH "trigger/current_trigger"
#define EVENTS_PATH             BASE_PATH "events/"
#define SENSOR_ENABLE_PATH      BASE_PATH "in_%s_en"
#define SENSOR_OFFSET_PATH      BASE_PATH "in_%s_offset"
#define SENSOR_SCALE_PATH       BASE_PATH "in_%s_scale"
#define SENSOR_SAMPLING_PATH    BASE_PATH "in_%s_sampling_frequency"
#define DEVICE_SAMPLING_PATH    BASE_PATH "sampling_frequency"
#define DEVICE_AVAIL_FREQ_PATH  BASE_PATH "sampling_frequency_available"
#define ILLUMINATION_CALIBPATH  BASE_PATH "in_illuminance_calibscale"
#define SENSOR_CALIB_BIAS_PATH  BASE_PATH "in_%s_calibbias"
#define MOUNTING_MATRIX_PATH    BASE_PATH "mounting_matrix"

#define CONFIGFS_TRIGGER_PATH   "/sys/kernel/config/iio/triggers/"

#define PROP_BASE               "ro.iio.%s.%s" /* Note: PROPERTY_KEY_MAX is small */

#define MAX_TYPE_SPEC_LEN       32      /* Channel type spec len; ex: "le:u10/16>>0" */
#define MAX_SENSOR_REPORT_SIZE  32      /* Sensor report buffer size */
#define MAX_DEVICE_REPORT_SIZE  32      /* iio device scan buffer size */

#define MAX_NAME_SIZE           32

#define MAX_SENSOR_BASES        3       /* Max number of base sensors a sensor can rely on */

#define ARRAY_SIZE(x) sizeof(x)/sizeof(x[0])
#define REPORTING_MODE(x)       ((x) & 0x06)

#define FILTER_TYPE_NONE                0
#define FILTER_TYPE_MOVING_AVERAGE      1
#define FILTER_TYPE_MEDIAN              2

#define MODE_AUTO       0 /* autodetect */
#define MODE_POLL       1
#define MODE_TRIGGER    2
#define MODE_EVENT      3


typedef struct
{
        const char *type; /* event type; e.g: transition */
        const char *dir;  /* event direction; e.g: rising */

        /* sysfs entries located in /sys/bus/iio/devices/iio:deviceX/events/ */
        const char *ev_en_path;
        const char *ev_value_path;
}
event_descriptor_t;


typedef struct
{
        const char *name;       /* channel name ; ex: x */

        /* sysfs entries located under scan_elements */
        const char *en_path;    /* Enabled sysfs file name ; ex: "in_temp_en" */
        const char *type_path;  /* _type sysfs file name  */
        const char *index_path; /* _index sysfs file name */

        /* sysfs entries located in /sys/bus/iio/devices/iio:deviceX */
        const char *raw_path;   /* _raw sysfs file name  */
        const char *input_path; /* _input sysfs file name */
        const char *scale_path; /* _scale sysfs file name */

        const int num_events;
        event_descriptor_t event[MAX_EVENTS];
}
channel_descriptor_t;


typedef struct
{
        const char *tag;        /* Prefix such as "accel", "gyro", "temp"... */
        const char *shorthand;
        const int type;         /* Sensor type ; ex: SENSOR_TYPE_ACCELEROMETER */
        const int num_channels; /* Expected iio channels for this sensor */
        const int is_virtual;   /* Is the sensor virtual or not */
        channel_descriptor_t channel[MAX_CHANNELS];
}
sensor_catalog_entry_t;


typedef struct
{
        char sign;
        char endianness;
        short realbits;
        short storagebits;
        short shift;
}
datum_info_t;


typedef struct
{
        int offset;     /* Offset in bytes within the iio character device report */
        int size;       /* Field size in bytes */
        float scale;    /* Scale for each channel */
        char type_spec[MAX_TYPE_SPEC_LEN];      /* From driver; ex: le:u10/16>>0 */
        datum_info_t type_info;                 /* Decoded contents of type spec */
        float opt_scale; /*
                          * Optional correction scale read from a property such as iio.accel.x.scale, allowing late compensation of
                          * problems such as misconfigured axes ; set to 1 by default. Applied at the end of the scaling process.
                          */
        int raw_path_present;   /* Flag signalling the presence of in_<sens>_<axis>_raw file */
        int input_path_present; /* Flag signalling the presence of in_<sens>_input file */
}
channel_info_t;


typedef struct
{
        /* Conversion function called once per channel */
        float (*transform) (int s, int c, unsigned char* sample_data);

        /* Function called once per sample */
        int (*finalize) (int s, sensors_event_t* data);
}
sample_ops_t;


/*
 * Whenever we have sensor data recorded for a sensor in the associated
 * sensor cell, its report_pending field is set to a non-zero value
 * indicating how we got this data.
 */
#define DATA_TRIGGER    1       /* From /dev/iio:device fd              */
#define DATA_SYSFS      2       /* Through polling                      */
#define DATA_DUPLICATE  3       /* Duplicate of triggered motion sample */


typedef struct
{
        char friendly_name[MAX_NAME_SIZE];      /* ex: Accelerometer         */
        char internal_name[MAX_NAME_SIZE];      /* ex: accel_3d              */
        char vendor_name[MAX_NAME_SIZE];        /* ex: Intel                 */
        char init_trigger_name[MAX_NAME_SIZE];  /* ex: accel-name-dev1       */
        char motion_trigger_name[MAX_NAME_SIZE];/* ex: accel-any-motion-dev1 */
        char hrtimer_trigger_name[MAX_NAME_SIZE]; /*ex: accel-hr-dev1 */
        int trigger_nr; /* trigger number associated with this device */
        float max_range;
        float resolution;
        float power;

        /*
         * Currently active trigger - either a pointer to the initial (default) trigger name buffer, or a pointer to the motion trigger name buffer,
         * or something else (typically NULL or a pointer to some static "\n". This is used to determine if the conditions are met to switch from
         * the default trigger to the motion trigger for a sensor, or rather for the interrupt-driven sensors associated to a given iio device.
         */
        const char* selected_trigger;

        float offset;           /* (cooked = raw + offset) * scale                      */
        float scale;            /* default:1. when set to 0, use channel specific value */
        float illumincalib;     /* to set the calibration for the ALS                   */

        float requested_rate;   /* requested events / second                            */
        float sampling_rate;    /* setup events / second                                */

        float min_supported_rate;
        float max_supported_rate;

        int dev_num;            /* Associated iio dev num, ex: 3 for /dev/iio:device3   */

        int catalog_index;      /* Associated entry within the sensor_catalog array     */
        int type;               /* Sensor type, such as SENSOR_TYPE_GYROSCOPE           */

        int num_channels;       /* Actual channel count ; 0 for poll mode sensors       */

        int mode;       /* Usage mode, ex: poll, trigger ... */

        /*
         * The array below indicates where to gather report data for this sensor inside the reports that we read from the iio character device.
         * It is updated whenever channels are enabled or disabled on the same device. Channel size indicates the size in bytes of fields, and
         * should be zero for disabled channels. The type field indicates how a specific channel data item is structured.
         */
        channel_info_t channel[MAX_CHANNELS];

        /*
         * This flag is set if we acquired data from the sensor but did not forward it to upper layers (i.e. Android) yet. If so, report_buffer
         * contains that data. Valid values are 0: empty, 1: normal, 2: repeat of last acquired value after timeout.
         */
        int report_pending;

        /* This flag is set if we have a meta data event pending */
        int meta_data_pending;

        /*
         * Timestamp closely matching the date of sampling, preferably retrieved from a iio channel alongside sample data. Value zero indicates that
         * we couldn't get such a closely correlated timestamp, and that one has to be generated before the report gets sent up to Android.
         */
        int64_t report_ts;

        /* Buffer containing the last generated sensor report for this sensor */
        unsigned char report_buffer[MAX_SENSOR_REPORT_SIZE];

        /* Whether or not the above buffer contains data from a device report */
        int report_initialized;

        /* Channel and sample finalization callbacks for this sensor */
        sample_ops_t ops;

        int cal_level; /* 0 means not calibrated */

        /*
         * Depending on the sensor, calibration may take too much time at higher levels. Allow optional capping to a certain level.
         */
        int max_cal_level;

        void *cal_data; /* Sensor calibration data, e.g. for magnetometer */

        void* filter;   /* Filtering data for noisy sensors */
        int filter_type;/* FILTER_ specification for this sensor ; default is FILTER_NONE */

        /* Previously reported value, for on-change sensors */
        union {
                float data;
                uint64_t data64;
        } prev_val;
        /*
         * Certain sensors expose their readings through sysfs files that have a long response time (100-200 ms for ALS). Rather than block our
         * global control loop for several hundred ms each second, offload those lengthy blocking reads to dedicated threads, which will then report
         * their data through a fd that we can add to our poll fd set.
         */
        int thread_data_fd[2];
        pthread_t acquisition_thread;

        int base_count; /* How many base sensors is the sensor depending on */
        int base[MAX_SENSOR_BASES];

        uint32_t quirks; /* Bit mask expressing the need for special tweaks */

        /* Note: we may have to explicitely serialize access to some fields */

        int is_virtual;                 /* Composite sensor, exposed from data acquired through other sensors */

        uint32_t ref_count;             /* Dependency count - for a real sensor how many active virtual sensors are depending on it */

        uint32_t directly_enabled;      /* Flag showing if a sensor was enabled directly by Android */

        /*
         * Current sample for a virtual sensor - when a report is ready we'll keep the data here until it's finally processed. Can be modified for
         * more than one at a later time.
         */
        sensors_event_t sample;
        uint64_t event_id;

        /*
         * If the QUIRK_FIELD_ORDERING bit is set in quirks, the contents of this array are used in the finalization stage to swap sample fields
         * before transmitting them to Android ; they form a mapping between the indices of the input and output arrays: ex: 0123 is identity for
         * a sample containing 4 fields.
         */
        unsigned char order[MAX_CHANNELS];

        /*
         * If the QUIRK_MOUNTING_MATRIX bit is set in quirks, the contents of this matrix is used to correct the sample values so that it takes
         * into account the way the sensor has been mounted on the PCB.
         */
        float mounting_matrix[9];

        /** Count of available frequencies */
        int avail_freqs_count;

        /** Array of available frequencies */
        float* avail_freqs;

        /*
         * Event counter - will be used to check if we have a significant sample for noisy sensors. We want to make sure we do not send any wrong
         * events before filtering kicks in. We can also use it for statistics.
         */
        uint64_t event_count;

        /* Some polled sensors need to be first enabled so that they start
         * computing a set of values in hardware (e.g step counter). Enabling
         * is done through a sysfs attribute in_<tag>_en
         */
        int needs_enable;

        float semi_arbitrated_rate;     /* Arbitrated sampling rate before we considered other sensors co-located on the same iio device */
}
sensor_info_t;


/* Reference a few commonly used variables... */
extern int                      sensor_count;
extern struct sensor_t          sensor_desc[MAX_SENSORS];
extern sensor_info_t            sensor[MAX_SENSORS];
extern sensor_catalog_entry_t   sensor_catalog[];
extern unsigned int             catalog_size;

/* Needed both in sensors and activity HALs */
void check_trig_sensors (int i, char *sysfs_file, char map[catalog_size]);
void check_poll_sensors (int i, char *sysfs_file, char map[catalog_size]);
void check_event_sensors (int i, char *sysfs_file, char map[catalog_size]);
void discover_sensors(int dev_num, char *sysfs_base_path, char map[catalog_size],
                      void (*discover_sensor)(int, char*, char*));

/*
 * Macros associating iio sysfs entries to to sensor types ; see
 * linux/kernel/drivers/iio/industrialio-core.c and
 * hardware/libhardware/include/hardware/sensor.h
 */

#define DECLARE_VOID_CHANNEL(tag)       \
                        tag,    \
                        "",     \
                        "",     \
                        "",     \
                        "",     \
                        "",     \
                        "",     \

#define DECLARE_CHANNEL(tag, spacer, name)              \
                        name,                           \
                        "in_"tag spacer name"_en",      \
                        "in_"tag spacer name"_type",    \
                        "in_"tag spacer name"_index",   \
                        "in_"tag spacer name"_raw",     \
                        "in_"tag spacer name"_input",   \
                        "in_"tag spacer name"_scale",   \
                        0, {{0}},

#define DECLARE_NAMED_CHANNEL(tag, name)        DECLARE_CHANNEL(tag, "_", name)

#define DECLARE_GENERIC_CHANNEL(tag)            DECLARE_CHANNEL(tag, "", "")

#define DECLARE_EVENT(tag, spacer1, name, spacer2, type, spacer3, dir)          \
                      type, dir,                                                \
                      "in_"tag spacer1 name spacer2 type spacer3 dir"_en",      \
                      "in_"tag spacer1 name spacer2 type spacer3 dir"_value",   \

#define DECLARE_GENERIC_EVENT(tag, name, type, dir) \
                DECLARE_EVENT(tag, "_", name, "_", type, "_", dir)
#define DECLARE_NAMED_EVENT(tag, name) \
                DECLARE_EVENT(tag, "_", name, "","","","")

#endif