// SPDX-License-Identifier: GPL-2.0-only
/*
 * HID Sensors Driver
 * Copyright (c) 2012, Intel Corporation.
 */
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/time.h>
#include <linux/units.h>

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

static const struct {
        u32 usage_id;
        int unit; /* 0 for default others from HID sensor spec */
        int scale_val0; /* scale, whole number */
        int scale_val1; /* scale, fraction in nanos */
} unit_conversion[] = {
        {HID_USAGE_SENSOR_ACCEL_3D, 0, 9, 806650000},
        {HID_USAGE_SENSOR_ACCEL_3D,
                HID_USAGE_SENSOR_UNITS_METERS_PER_SEC_SQRD, 1, 0},
        {HID_USAGE_SENSOR_ACCEL_3D,
                HID_USAGE_SENSOR_UNITS_G, 9, 806650000},

        {HID_USAGE_SENSOR_GRAVITY_VECTOR, 0, 9, 806650000},
        {HID_USAGE_SENSOR_GRAVITY_VECTOR,
                HID_USAGE_SENSOR_UNITS_METERS_PER_SEC_SQRD, 1, 0},
        {HID_USAGE_SENSOR_GRAVITY_VECTOR,
                HID_USAGE_SENSOR_UNITS_G, 9, 806650000},

        {HID_USAGE_SENSOR_GYRO_3D, 0, 0, 17453293},
        {HID_USAGE_SENSOR_GYRO_3D,
                HID_USAGE_SENSOR_UNITS_RADIANS_PER_SECOND, 1, 0},
        {HID_USAGE_SENSOR_GYRO_3D,
                HID_USAGE_SENSOR_UNITS_DEGREES_PER_SECOND, 0, 17453293},

        {HID_USAGE_SENSOR_COMPASS_3D, 0, 0, 1000000},
        {HID_USAGE_SENSOR_COMPASS_3D, HID_USAGE_SENSOR_UNITS_GAUSS, 1, 0},

        {HID_USAGE_SENSOR_INCLINOMETER_3D, 0, 0, 17453293},
        {HID_USAGE_SENSOR_INCLINOMETER_3D,
                HID_USAGE_SENSOR_UNITS_DEGREES, 0, 17453293},
        {HID_USAGE_SENSOR_INCLINOMETER_3D,
                HID_USAGE_SENSOR_UNITS_RADIANS, 1, 0},

        {HID_USAGE_SENSOR_ALS, 0, 1, 0},
        {HID_USAGE_SENSOR_ALS, HID_USAGE_SENSOR_UNITS_LUX, 1, 0},

        {HID_USAGE_SENSOR_PRESSURE, 0, 100, 0},
        {HID_USAGE_SENSOR_PRESSURE, HID_USAGE_SENSOR_UNITS_PASCAL, 0, 1000000},

        {HID_USAGE_SENSOR_TIME_TIMESTAMP, 0, 1000000000, 0},
        {HID_USAGE_SENSOR_TIME_TIMESTAMP, HID_USAGE_SENSOR_UNITS_MILLISECOND,
                1000000, 0},

        {HID_USAGE_SENSOR_DEVICE_ORIENTATION, 0, 1, 0},

        {HID_USAGE_SENSOR_RELATIVE_ORIENTATION, 0, 1, 0},

        {HID_USAGE_SENSOR_GEOMAGNETIC_ORIENTATION, 0, 1, 0},

        {HID_USAGE_SENSOR_TEMPERATURE, 0, 1000, 0},
        {HID_USAGE_SENSOR_TEMPERATURE, HID_USAGE_SENSOR_UNITS_DEGREES, 1000, 0},

        {HID_USAGE_SENSOR_HUMIDITY, 0, 1000, 0},
        {HID_USAGE_SENSOR_HINGE, 0, 0, 17453293},
        {HID_USAGE_SENSOR_HINGE, HID_USAGE_SENSOR_UNITS_DEGREES, 0, 17453293},

        {HID_USAGE_SENSOR_HUMAN_PRESENCE, 0, 1, 0},
        {HID_USAGE_SENSOR_HUMAN_PROXIMITY, 0, 1, 0},
        {HID_USAGE_SENSOR_HUMAN_ATTENTION, 0, 1, 0},
};

static void simple_div(int dividend, int divisor, int *whole,
                                int *micro_frac)
{
        int rem;
        int exp = 0;

        *micro_frac = 0;
        if (divisor == 0) {
                *whole = 0;
                return;
        }
        *whole = dividend/divisor;
        rem = dividend % divisor;
        if (rem) {
                while (rem <= divisor) {
                        rem *= 10;
                        exp++;
                }
                *micro_frac = (rem / divisor) * int_pow(10, 6 - exp);
        }
}

static void split_micro_fraction(unsigned int no, int exp, int *val1, int *val2)
{
        int divisor = int_pow(10, exp);

        *val1 = no / divisor;
        *val2 = no % divisor * int_pow(10, 6 - exp);
}

/*
VTF format uses exponent and variable size format.
For example if the size is 2 bytes
0x0067 with VTF16E14 format -> +1.03
To convert just change to 0x67 to decimal and use two decimal as E14 stands
for 10^-2.
Negative numbers are 2's complement
*/
static void convert_from_vtf_format(u32 value, int size, int exp,
                                        int *val1, int *val2)
{
        int sign = 1;

        if (value & BIT(size*8 - 1)) {
                value =  ((1LL << (size * 8)) - value);
                sign = -1;
        }
        exp = hid_sensor_convert_exponent(exp);
        if (exp >= 0) {
                *val1 = sign * value * int_pow(10, exp);
                *val2 = 0;
        } else {
                split_micro_fraction(value, -exp, val1, val2);
                if (*val1)
                        *val1 = sign * (*val1);
                else
                        *val2 = sign * (*val2);
        }
}

static u32 convert_to_vtf_format(int size, int exp, int val1, int val2)
{
        int divisor;
        u32 value;
        int sign = 1;

        if (val1 < 0 || val2 < 0)
                sign = -1;
        exp = hid_sensor_convert_exponent(exp);
        if (exp < 0) {
                divisor = int_pow(10, 6 + exp);
                value = abs(val1) * int_pow(10, -exp);
                value += abs(val2) / divisor;
        } else {
                divisor = int_pow(10, exp);
                value = abs(val1) / divisor;
        }
        if (sign < 0)
                value =  ((1LL << (size * 8)) - value);

        return value;
}

s32 hid_sensor_read_poll_value(struct hid_sensor_common *st)
{
        s32 value = 0;
        int ret;

        ret = sensor_hub_get_feature(st->hsdev,
                                     st->poll.report_id,
                                     st->poll.index, sizeof(value), &value);

        if (ret < 0 || value < 0) {
                return -EINVAL;
        } else {
                if (st->poll.units == HID_USAGE_SENSOR_UNITS_SECOND)
                        value = value * 1000;
        }

        return value;
}
EXPORT_SYMBOL_NS(hid_sensor_read_poll_value, "IIO_HID_ATTRIBUTES");

int hid_sensor_read_samp_freq_value(struct hid_sensor_common *st,
                                int *val1, int *val2)
{
        s32 value;
        int ret;

        ret = sensor_hub_get_feature(st->hsdev,
                                     st->poll.report_id,
                                     st->poll.index, sizeof(value), &value);
        if (ret < 0 || value < 0) {
                *val1 = *val2 = 0;
                return -EINVAL;
        } else {
                if (st->poll.units == HID_USAGE_SENSOR_UNITS_MILLISECOND)
                        simple_div(1000, value, val1, val2);
                else if (st->poll.units == HID_USAGE_SENSOR_UNITS_SECOND)
                        simple_div(1, value, val1, val2);
                else {
                        *val1 = *val2 = 0;
                        return -EINVAL;
                }
        }

        return IIO_VAL_INT_PLUS_MICRO;
}
EXPORT_SYMBOL_NS(hid_sensor_read_samp_freq_value, "IIO_HID");

int hid_sensor_write_samp_freq_value(struct hid_sensor_common *st,
                                int val1, int val2)
{
        s32 value;
        int ret;

        if (val1 < 0 || val2 < 0)
                return -EINVAL;

        value = val1 * HZ_PER_MHZ + val2;
        if (value) {
                if (st->poll.units == HID_USAGE_SENSOR_UNITS_MILLISECOND)
                        value = NSEC_PER_SEC / value;
                else if (st->poll.units == HID_USAGE_SENSOR_UNITS_SECOND)
                        value = USEC_PER_SEC / value;
                else
                        value = 0;
        }
        ret = sensor_hub_set_feature(st->hsdev, st->poll.report_id,
                                     st->poll.index, sizeof(value), &value);
        if (ret < 0 || value < 0)
                return -EINVAL;

        ret = sensor_hub_get_feature(st->hsdev,
                                     st->poll.report_id,
                                     st->poll.index, sizeof(value), &value);
        if (ret < 0 || value < 0)
                return -EINVAL;

        st->poll_interval = value;

        return 0;
}
EXPORT_SYMBOL_NS(hid_sensor_write_samp_freq_value, "IIO_HID");

int hid_sensor_read_raw_hyst_value(struct hid_sensor_common *st,
                                int *val1, int *val2)
{
        s32 value;
        int ret;

        ret = sensor_hub_get_feature(st->hsdev,
                                     st->sensitivity.report_id,
                                     st->sensitivity.index, sizeof(value),
                                     &value);
        if (ret < 0 || value < 0) {
                *val1 = *val2 = 0;
                return -EINVAL;
        } else {
                convert_from_vtf_format(value, st->sensitivity.size,
                                        st->sensitivity.unit_expo,
                                        val1, val2);
        }

        return IIO_VAL_INT_PLUS_MICRO;
}
EXPORT_SYMBOL_NS(hid_sensor_read_raw_hyst_value, "IIO_HID");

int hid_sensor_read_raw_hyst_rel_value(struct hid_sensor_common *st, int *val1,
                                       int *val2)
{
        s32 value;
        int ret;

        ret = sensor_hub_get_feature(st->hsdev,
                                     st->sensitivity_rel.report_id,
                                     st->sensitivity_rel.index, sizeof(value),
                                     &value);
        if (ret < 0 || value < 0) {
                *val1 = *val2 = 0;
                return -EINVAL;
        }

        convert_from_vtf_format(value, st->sensitivity_rel.size,
                                st->sensitivity_rel.unit_expo, val1, val2);

        return IIO_VAL_INT_PLUS_MICRO;
}
EXPORT_SYMBOL_NS(hid_sensor_read_raw_hyst_rel_value, "IIO_HID");


int hid_sensor_write_raw_hyst_value(struct hid_sensor_common *st,
                                        int val1, int val2)
{
        s32 value;
        int ret;

        if (val1 < 0 || val2 < 0)
                return -EINVAL;

        value = convert_to_vtf_format(st->sensitivity.size,
                                st->sensitivity.unit_expo,
                                val1, val2);
        ret = sensor_hub_set_feature(st->hsdev, st->sensitivity.report_id,
                                     st->sensitivity.index, sizeof(value),
                                     &value);
        if (ret < 0 || value < 0)
                return -EINVAL;

        ret = sensor_hub_get_feature(st->hsdev,
                                     st->sensitivity.report_id,
                                     st->sensitivity.index, sizeof(value),
                                     &value);
        if (ret < 0 || value < 0)
                return -EINVAL;

        st->raw_hystersis = value;

        return 0;
}
EXPORT_SYMBOL_NS(hid_sensor_write_raw_hyst_value, "IIO_HID");

int hid_sensor_write_raw_hyst_rel_value(struct hid_sensor_common *st,
                                        int val1, int val2)
{
        s32 value;
        int ret;

        if (val1 < 0 || val2 < 0)
                return -EINVAL;

        value = convert_to_vtf_format(st->sensitivity_rel.size,
                                st->sensitivity_rel.unit_expo,
                                val1, val2);
        ret = sensor_hub_set_feature(st->hsdev, st->sensitivity_rel.report_id,
                                     st->sensitivity_rel.index, sizeof(value),
                                     &value);
        if (ret < 0 || value < 0)
                return -EINVAL;

        ret = sensor_hub_get_feature(st->hsdev,
                                     st->sensitivity_rel.report_id,
                                     st->sensitivity_rel.index, sizeof(value),
                                     &value);
        if (ret < 0 || value < 0)
                return -EINVAL;

        st->raw_hystersis = value;

        return 0;
}
EXPORT_SYMBOL_NS(hid_sensor_write_raw_hyst_rel_value, "IIO_HID");

/*
 * This fuction applies the unit exponent to the scale.
 * For example:
 * 9.806650000 ->exp:2-> val0[980]val1[665000000]
 * 9.000806000 ->exp:2-> val0[900]val1[80600000]
 * 0.174535293 ->exp:2-> val0[17]val1[453529300]
 * 1.001745329 ->exp:0-> val0[1]val1[1745329]
 * 1.001745329 ->exp:2-> val0[100]val1[174532900]
 * 1.001745329 ->exp:4-> val0[10017]val1[453290000]
 * 9.806650000 ->exp:-2-> val0[0]val1[98066500]
 */
static void adjust_exponent_nano(int *val0, int *val1, int scale0,
                                  int scale1, int exp)
{
        int divisor;
        int i;
        int x;
        int res;
        int rem;

        if (exp > 0) {
                *val0 = scale0 * int_pow(10, exp);
                res = 0;
                if (exp > 9) {
                        *val1 = 0;
                        return;
                }
                for (i = 0; i < exp; ++i) {
                        divisor = int_pow(10, 8 - i);
                        x = scale1 / divisor;
                        res += int_pow(10, exp - 1 - i) * x;
                        scale1 = scale1 % divisor;
                }
                *val0 += res;
                *val1 = scale1 * int_pow(10, exp);
        } else if (exp < 0) {
                exp = abs(exp);
                if (exp > 9) {
                        *val0 = *val1 = 0;
                        return;
                }
                divisor = int_pow(10, exp);
                *val0 = scale0 / divisor;
                rem = scale0 % divisor;
                res = 0;
                for (i = 0; i < (9 - exp); ++i) {
                        divisor = int_pow(10, 8 - i);
                        x = scale1 / divisor;
                        res += int_pow(10, 8 - exp - i) * x;
                        scale1 = scale1 % divisor;
                }
                *val1 = rem * int_pow(10, 9 - exp) + res;
        } else {
                *val0 = scale0;
                *val1 = scale1;
        }
}

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

        *val0 = 1;
        *val1 = 0;

        for (i = 0; i < ARRAY_SIZE(unit_conversion); ++i) {
                if (unit_conversion[i].usage_id == usage_id &&
                        unit_conversion[i].unit == attr_info->units) {
                        exp  = hid_sensor_convert_exponent(
                                                attr_info->unit_expo);
                        adjust_exponent_nano(val0, val1,
                                        unit_conversion[i].scale_val0,
                                        unit_conversion[i].scale_val1, exp);
                        break;
                }
        }

        return IIO_VAL_INT_PLUS_NANO;
}
EXPORT_SYMBOL_NS(hid_sensor_format_scale, "IIO_HID");

int64_t hid_sensor_convert_timestamp(struct hid_sensor_common *st,
                                     int64_t raw_value)
{
        return st->timestamp_ns_scale * raw_value;
}
EXPORT_SYMBOL_NS(hid_sensor_convert_timestamp, "IIO_HID");

static
int hid_sensor_get_reporting_interval(struct hid_sensor_hub_device *hsdev,
                                        u32 usage_id,
                                        struct hid_sensor_common *st)
{
        sensor_hub_input_get_attribute_info(hsdev,
                                        HID_FEATURE_REPORT, usage_id,
                                        HID_USAGE_SENSOR_PROP_REPORT_INTERVAL,
                                        &st->poll);
        /* Default unit of measure is milliseconds */
        if (st->poll.units == 0)
                st->poll.units = HID_USAGE_SENSOR_UNITS_MILLISECOND;

        st->poll_interval = -1;

        return 0;

}

static void hid_sensor_get_report_latency_info(struct hid_sensor_hub_device *hsdev,
                                               u32 usage_id,
                                               struct hid_sensor_common *st)
{
        sensor_hub_input_get_attribute_info(hsdev, HID_FEATURE_REPORT,
                                            usage_id,
                                            HID_USAGE_SENSOR_PROP_REPORT_LATENCY,
                                            &st->report_latency);

        hid_dbg(hsdev->hdev, "Report latency attributes: %x:%x\n",
                st->report_latency.index, st->report_latency.report_id);
}

int hid_sensor_get_report_latency(struct hid_sensor_common *st)
{
        int ret;
        int value;

        ret = sensor_hub_get_feature(st->hsdev, st->report_latency.report_id,
                                     st->report_latency.index, sizeof(value),
                                     &value);
        if (ret < 0)
                return ret;

        return value;
}
EXPORT_SYMBOL_NS(hid_sensor_get_report_latency, "IIO_HID_ATTRIBUTES");

int hid_sensor_set_report_latency(struct hid_sensor_common *st, int latency_ms)
{
        return sensor_hub_set_feature(st->hsdev, st->report_latency.report_id,
                                      st->report_latency.index,
                                      sizeof(latency_ms), &latency_ms);
}
EXPORT_SYMBOL_NS(hid_sensor_set_report_latency, "IIO_HID_ATTRIBUTES");

bool hid_sensor_batch_mode_supported(struct hid_sensor_common *st)
{
        return st->report_latency.index > 0 && st->report_latency.report_id > 0;
}
EXPORT_SYMBOL_NS(hid_sensor_batch_mode_supported, "IIO_HID_ATTRIBUTES");

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)
{

        struct hid_sensor_hub_attribute_info timestamp;
        s32 value;
        int ret;
        int i;

        hid_sensor_get_reporting_interval(hsdev, usage_id, st);

        sensor_hub_input_get_attribute_info(hsdev,
                                        HID_FEATURE_REPORT, usage_id,
                                        HID_USAGE_SENSOR_PROP_REPORT_STATE,
                                        &st->report_state);

        sensor_hub_input_get_attribute_info(hsdev,
                                        HID_FEATURE_REPORT, usage_id,
                                        HID_USAGE_SENSOR_PROY_POWER_STATE,
                                        &st->power_state);

        st->power_state.logical_minimum = 1;
        st->report_state.logical_minimum = 1;

        sensor_hub_input_get_attribute_info(hsdev,
                        HID_FEATURE_REPORT, usage_id,
                        HID_USAGE_SENSOR_PROP_SENSITIVITY_ABS,
                         &st->sensitivity);

        sensor_hub_input_get_attribute_info(hsdev,
                        HID_FEATURE_REPORT, usage_id,
                        HID_USAGE_SENSOR_PROP_SENSITIVITY_REL_PCT,
                        &st->sensitivity_rel);
        /*
         * Set Sensitivity field ids, when there is no individual modifier, will
         * check absolute sensitivity and relative sensitivity of data field
         */
        for (i = 0; i < sensitivity_addresses_len; i++) {
                if (st->sensitivity.index < 0)
                        sensor_hub_input_get_attribute_info(
                                hsdev, HID_FEATURE_REPORT, usage_id,
                                HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
                                        sensitivity_addresses[i],
                                &st->sensitivity);

                if (st->sensitivity_rel.index < 0)
                        sensor_hub_input_get_attribute_info(
                                hsdev, HID_FEATURE_REPORT, usage_id,
                                HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_REL_PCT |
                                        sensitivity_addresses[i],
                                &st->sensitivity_rel);
        }

        st->raw_hystersis = -1;

        sensor_hub_input_get_attribute_info(hsdev,
                                            HID_INPUT_REPORT, usage_id,
                                            HID_USAGE_SENSOR_TIME_TIMESTAMP,
                                            &timestamp);
        if (timestamp.index >= 0 && timestamp.report_id) {
                int val0, val1;

                hid_sensor_format_scale(HID_USAGE_SENSOR_TIME_TIMESTAMP,
                                        &timestamp, &val0, &val1);
                st->timestamp_ns_scale = val0;
        } else
                st->timestamp_ns_scale = 1000000000;

        hid_sensor_get_report_latency_info(hsdev, usage_id, st);

        hid_dbg(hsdev->hdev, "common attributes: %x:%x, %x:%x, %x:%x %x:%x %x:%x\n",
                st->poll.index, st->poll.report_id,
                st->report_state.index, st->report_state.report_id,
                st->power_state.index, st->power_state.report_id,
                st->sensitivity.index, st->sensitivity.report_id,
                timestamp.index, timestamp.report_id);

        ret = sensor_hub_get_feature(hsdev,
                                st->power_state.report_id,
                                st->power_state.index, sizeof(value), &value);
        if (ret < 0)
                return ret;
        if (value < 0)
                return -EINVAL;

        return 0;
}
EXPORT_SYMBOL_NS(hid_sensor_parse_common_attributes, "IIO_HID");

MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@intel.com>");
MODULE_DESCRIPTION("HID Sensor common attribute processing");
MODULE_LICENSE("GPL");