// SPDX-License-Identifier: GPL-2.0-only
/*
 * HID Sensors Driver
 * Copyright (c) 2017, Intel Corporation.
 */
#include <linux/device.h>
#include <linux/hid-sensor-hub.h>
#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>

#include "../common/hid-sensors/hid-sensor-trigger.h"

struct temperature_state {
        struct hid_sensor_common common_attributes;
        struct hid_sensor_hub_attribute_info temperature_attr;
        struct {
                s32 temperature_data;
                aligned_s64 timestamp;
        } scan;
        int scale_pre_decml;
        int scale_post_decml;
        int scale_precision;
        int value_offset;
};

static const u32 temperature_sensitivity_addresses[] = {
        HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
};

/* Channel definitions */
static const struct iio_chan_spec temperature_channels[] = {
        {
                .type = IIO_TEMP,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
                .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
                        BIT(IIO_CHAN_INFO_SCALE) |
                        BIT(IIO_CHAN_INFO_SAMP_FREQ) |
                        BIT(IIO_CHAN_INFO_HYSTERESIS),
        },
        IIO_CHAN_SOFT_TIMESTAMP(1),
};

/* Adjust channel real bits based on report descriptor */
static void temperature_adjust_channel_bit_mask(struct iio_chan_spec *channels,
                                        int channel, int size)
{
        channels[channel].scan_type.sign = 's';
        /* Real storage bits will change based on the report desc. */
        channels[channel].scan_type.realbits = size * 8;
        /* Maximum size of a sample to capture is s32 */
        channels[channel].scan_type.storagebits = sizeof(s32) * 8;
}

static int temperature_read_raw(struct iio_dev *indio_dev,
                                struct iio_chan_spec const *chan,
                                int *val, int *val2, long mask)
{
        struct temperature_state *temp_st = iio_priv(indio_dev);

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                if (chan->type != IIO_TEMP)
                        return -EINVAL;
                hid_sensor_power_state(
                        &temp_st->common_attributes, true);
                *val = sensor_hub_input_attr_get_raw_value(
                        temp_st->common_attributes.hsdev,
                        HID_USAGE_SENSOR_TEMPERATURE,
                        HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
                        temp_st->temperature_attr.report_id,
                        SENSOR_HUB_SYNC,
                        temp_st->temperature_attr.logical_minimum < 0);
                hid_sensor_power_state(
                                &temp_st->common_attributes,
                                false);

                return IIO_VAL_INT;

        case IIO_CHAN_INFO_SCALE:
                *val = temp_st->scale_pre_decml;
                *val2 = temp_st->scale_post_decml;
                return temp_st->scale_precision;

        case IIO_CHAN_INFO_OFFSET:
                *val = temp_st->value_offset;
                return IIO_VAL_INT;

        case IIO_CHAN_INFO_SAMP_FREQ:
                return hid_sensor_read_samp_freq_value(
                                &temp_st->common_attributes, val, val2);

        case IIO_CHAN_INFO_HYSTERESIS:
                return hid_sensor_read_raw_hyst_value(
                                &temp_st->common_attributes, val, val2);
        default:
                return -EINVAL;
        }
}

static int temperature_write_raw(struct iio_dev *indio_dev,
                                struct iio_chan_spec const *chan,
                                int val, int val2, long mask)
{
        struct temperature_state *temp_st = iio_priv(indio_dev);

        switch (mask) {
        case IIO_CHAN_INFO_SAMP_FREQ:
                return hid_sensor_write_samp_freq_value(
                                &temp_st->common_attributes, val, val2);
        case IIO_CHAN_INFO_HYSTERESIS:
                return hid_sensor_write_raw_hyst_value(
                                &temp_st->common_attributes, val, val2);
        default:
                return -EINVAL;
        }
}

static const struct iio_info temperature_info = {
        .read_raw = &temperature_read_raw,
        .write_raw = &temperature_write_raw,
};

/* Callback handler to send event after all samples are received and captured */
static int temperature_proc_event(struct hid_sensor_hub_device *hsdev,
                                unsigned int usage_id, void *pdev)
{
        struct iio_dev *indio_dev = platform_get_drvdata(pdev);
        struct temperature_state *temp_st = iio_priv(indio_dev);

        if (atomic_read(&temp_st->common_attributes.data_ready))
                iio_push_to_buffers_with_ts(indio_dev, &temp_st->scan,
                                            sizeof(temp_st->scan),
                                            iio_get_time_ns(indio_dev));

        return 0;
}

/* Capture samples in local storage */
static int temperature_capture_sample(struct hid_sensor_hub_device *hsdev,
                                unsigned int usage_id, size_t raw_len,
                                char *raw_data, void *pdev)
{
        struct iio_dev *indio_dev = platform_get_drvdata(pdev);
        struct temperature_state *temp_st = iio_priv(indio_dev);

        switch (usage_id) {
        case HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE:
                temp_st->scan.temperature_data = *(s32 *)raw_data;
                return 0;
        default:
                return -EINVAL;
        }
}

/* Parse report which is specific to an usage id*/
static int temperature_parse_report(struct platform_device *pdev,
                                struct hid_sensor_hub_device *hsdev,
                                struct iio_chan_spec *channels,
                                unsigned int usage_id,
                                struct temperature_state *st)
{
        int ret;

        ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
                        usage_id,
                        HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
                        &st->temperature_attr);
        if (ret < 0)
                return ret;

        temperature_adjust_channel_bit_mask(channels, 0,
                                        st->temperature_attr.size);

        st->scale_precision = hid_sensor_format_scale(
                                HID_USAGE_SENSOR_TEMPERATURE,
                                &st->temperature_attr,
                                &st->scale_pre_decml, &st->scale_post_decml);

        return ret;
}

static struct hid_sensor_hub_callbacks temperature_callbacks = {
        .send_event = &temperature_proc_event,
        .capture_sample = &temperature_capture_sample,
};

/* Function to initialize the processing for usage id */
static int hid_temperature_probe(struct platform_device *pdev)
{
        static const char *name = "temperature";
        struct iio_dev *indio_dev;
        struct temperature_state *temp_st;
        struct iio_chan_spec *temp_chans;
        struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
        int ret;

        indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*temp_st));
        if (!indio_dev)
                return -ENOMEM;

        temp_st = iio_priv(indio_dev);
        temp_st->common_attributes.hsdev = hsdev;
        temp_st->common_attributes.pdev = pdev;

        ret = hid_sensor_parse_common_attributes(hsdev,
                                        HID_USAGE_SENSOR_TEMPERATURE,
                                        &temp_st->common_attributes,
                                        temperature_sensitivity_addresses,
                                        ARRAY_SIZE(temperature_sensitivity_addresses));
        if (ret)
                return ret;

        temp_chans = devm_kmemdup(&indio_dev->dev, temperature_channels,
                                sizeof(temperature_channels), GFP_KERNEL);
        if (!temp_chans)
                return -ENOMEM;

        ret = temperature_parse_report(pdev, hsdev, temp_chans,
                                HID_USAGE_SENSOR_TEMPERATURE, temp_st);
        if (ret)
                return ret;

        indio_dev->channels = temp_chans;
        indio_dev->num_channels = ARRAY_SIZE(temperature_channels);
        indio_dev->info = &temperature_info;
        indio_dev->name = name;
        indio_dev->modes = INDIO_DIRECT_MODE;

        atomic_set(&temp_st->common_attributes.data_ready, 0);

        ret = hid_sensor_setup_trigger(indio_dev, name,
                                &temp_st->common_attributes);
        if (ret)
                return ret;

        platform_set_drvdata(pdev, indio_dev);

        temperature_callbacks.pdev = pdev;
        ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_TEMPERATURE,
                                        &temperature_callbacks);
        if (ret)
                goto error_remove_trigger;

        ret = devm_iio_device_register(indio_dev->dev.parent, indio_dev);
        if (ret)
                goto error_remove_callback;

        return ret;

error_remove_callback:
        sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TEMPERATURE);
error_remove_trigger:
        hid_sensor_remove_trigger(indio_dev, &temp_st->common_attributes);
        return ret;
}

/* Function to deinitialize the processing for usage id */
static void hid_temperature_remove(struct platform_device *pdev)
{
        struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
        struct iio_dev *indio_dev = platform_get_drvdata(pdev);
        struct temperature_state *temp_st = iio_priv(indio_dev);

        sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TEMPERATURE);
        hid_sensor_remove_trigger(indio_dev, &temp_st->common_attributes);
}

static const struct platform_device_id hid_temperature_ids[] = {
        {
                /* Format: HID-SENSOR-usage_id_in_hex_lowercase */
                .name = "HID-SENSOR-200033",
        },
        { }
};
MODULE_DEVICE_TABLE(platform, hid_temperature_ids);

static struct platform_driver hid_temperature_platform_driver = {
        .id_table = hid_temperature_ids,
        .driver = {
                .name   = "temperature-sensor",
                .pm     = &hid_sensor_pm_ops,
        },
        .probe          = hid_temperature_probe,
        .remove         = hid_temperature_remove,
};
module_platform_driver(hid_temperature_platform_driver);

MODULE_DESCRIPTION("HID Environmental temperature sensor");
MODULE_AUTHOR("Song Hongyan <hongyan.song@intel.com>");
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS("IIO_HID");