// SPDX-License-Identifier: GPL-2.0-only
/*
 * HID Sensors Driver
 * Copyright (c) 2014, Intel Corporation.
 */
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/slab.h>
#include <linux/hid-sensor-hub.h>
#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include "../common/hid-sensors/hid-sensor-trigger.h"

static const u32 prox_usage_ids[] = {
        HID_USAGE_SENSOR_HUMAN_PRESENCE,
        HID_USAGE_SENSOR_HUMAN_PROXIMITY,
        HID_USAGE_SENSOR_HUMAN_ATTENTION,
};

#define MAX_CHANNELS ARRAY_SIZE(prox_usage_ids)

enum {
        HID_HUMAN_PRESENCE,
        HID_HUMAN_PROXIMITY,
        HID_HUMAN_ATTENTION,
};

struct prox_state {
        struct hid_sensor_hub_callbacks callbacks;
        struct hid_sensor_common common_attributes;
        struct hid_sensor_hub_attribute_info prox_attr[MAX_CHANNELS];
        struct iio_chan_spec channels[MAX_CHANNELS];
        u32 channel2usage[MAX_CHANNELS];
        u32 human_presence[MAX_CHANNELS];
        int scale_pre_decml[MAX_CHANNELS];
        int scale_post_decml[MAX_CHANNELS];
        int scale_precision[MAX_CHANNELS];
        unsigned long scan_mask[2]; /* One entry plus one terminator. */
        int num_channels;
};

static const u32 prox_sensitivity_addresses[] = {
        HID_USAGE_SENSOR_HUMAN_PRESENCE,
        HID_USAGE_SENSOR_DATA_PRESENCE,
};

#define PROX_CHANNEL(_is_proximity, _channel) \
        {\
                .type = _is_proximity ? IIO_PROXIMITY : IIO_ATTENTION,\
                .info_mask_separate = \
                (_is_proximity ? BIT(IIO_CHAN_INFO_RAW) :\
                                BIT(IIO_CHAN_INFO_PROCESSED)) |\
                BIT(IIO_CHAN_INFO_OFFSET) |\
                BIT(IIO_CHAN_INFO_SCALE) |\
                BIT(IIO_CHAN_INFO_SAMP_FREQ) |\
                BIT(IIO_CHAN_INFO_HYSTERESIS),\
                .indexed = _is_proximity,\
                .channel = _channel,\
        }

/* Channel definitions (same order as prox_usage_ids) */
static const struct iio_chan_spec prox_channels[] = {
        PROX_CHANNEL(true, HID_HUMAN_PRESENCE),
        PROX_CHANNEL(true, HID_HUMAN_PROXIMITY),
        PROX_CHANNEL(false, 0),
};

/* Adjust channel real bits based on report descriptor */
static void prox_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 u32 */
        channels[channel].scan_type.storagebits = sizeof(u32) * 8;
}

/* Channel read_raw handler */
static int prox_read_raw(struct iio_dev *indio_dev,
                              struct iio_chan_spec const *chan,
                              int *val, int *val2,
                              long mask)
{
        struct prox_state *prox_state = iio_priv(indio_dev);
        struct hid_sensor_hub_device *hsdev;
        int report_id;
        u32 address;
        int ret_type;
        s32 min;

        *val = 0;
        *val2 = 0;
        switch (mask) {
        case IIO_CHAN_INFO_RAW:
        case IIO_CHAN_INFO_PROCESSED:
                if (chan->scan_index >= prox_state->num_channels)
                        return -EINVAL;
                address = prox_state->channel2usage[chan->scan_index];
                report_id = prox_state->prox_attr[chan->scan_index].report_id;
                hsdev = prox_state->common_attributes.hsdev;
                min = prox_state->prox_attr[chan->scan_index].logical_minimum;
                hid_sensor_power_state(&prox_state->common_attributes, true);
                *val = sensor_hub_input_attr_get_raw_value(hsdev,
                                                           hsdev->usage,
                                                           address,
                                                           report_id,
                                                           SENSOR_HUB_SYNC,
                                                           min < 0);
                if (prox_state->channel2usage[chan->scan_index] ==
                    HID_USAGE_SENSOR_HUMAN_ATTENTION)
                        *val *= 100;
                hid_sensor_power_state(&prox_state->common_attributes, false);
                ret_type = IIO_VAL_INT;
                break;
        case IIO_CHAN_INFO_SCALE:
                if (chan->scan_index >= prox_state->num_channels)
                        return -EINVAL;

                *val = prox_state->scale_pre_decml[chan->scan_index];
                *val2 = prox_state->scale_post_decml[chan->scan_index];
                ret_type = prox_state->scale_precision[chan->scan_index];
                break;
        case IIO_CHAN_INFO_OFFSET:
                *val = 0;
                ret_type = IIO_VAL_INT;
                break;
        case IIO_CHAN_INFO_SAMP_FREQ:
                ret_type = hid_sensor_read_samp_freq_value(
                                &prox_state->common_attributes, val, val2);
                break;
        case IIO_CHAN_INFO_HYSTERESIS:
                ret_type = hid_sensor_read_raw_hyst_value(
                                &prox_state->common_attributes, val, val2);
                break;
        default:
                ret_type = -EINVAL;
                break;
        }

        return ret_type;
}

/* Channel write_raw handler */
static int prox_write_raw(struct iio_dev *indio_dev,
                               struct iio_chan_spec const *chan,
                               int val,
                               int val2,
                               long mask)
{
        struct prox_state *prox_state = iio_priv(indio_dev);
        int ret = 0;

        switch (mask) {
        case IIO_CHAN_INFO_SAMP_FREQ:
                ret = hid_sensor_write_samp_freq_value(
                                &prox_state->common_attributes, val, val2);
                break;
        case IIO_CHAN_INFO_HYSTERESIS:
                ret = hid_sensor_write_raw_hyst_value(
                                &prox_state->common_attributes, val, val2);
                break;
        default:
                ret = -EINVAL;
        }

        return ret;
}

static const struct iio_info prox_info = {
        .read_raw = &prox_read_raw,
        .write_raw = &prox_write_raw,
};

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

        dev_dbg(&indio_dev->dev, "prox_proc_event\n");
        if (atomic_read(&prox_state->common_attributes.data_ready)) {
                dev_dbg(&indio_dev->dev, "hid_sensor_push_data\n");
                iio_push_to_buffers(indio_dev, &prox_state->human_presence);
        }

        return 0;
}

/* Capture samples in local storage */
static int prox_capture_sample(struct hid_sensor_hub_device *hsdev,
                                unsigned usage_id,
                                size_t raw_len, char *raw_data,
                                void *priv)
{
        struct iio_dev *indio_dev = platform_get_drvdata(priv);
        struct prox_state *prox_state = iio_priv(indio_dev);
        int multiplier = 1;
        int chan;

        for (chan = 0; chan < prox_state->num_channels; chan++)
                if (prox_state->channel2usage[chan] == usage_id)
                        break;
        if (chan == prox_state->num_channels)
                return -EINVAL;

        if (usage_id == HID_USAGE_SENSOR_HUMAN_ATTENTION)
                multiplier = 100;

        switch (raw_len) {
        case 1:
                prox_state->human_presence[chan] = *(u8 *)raw_data * multiplier;
                return 0;
        case 2:
                prox_state->human_presence[chan] = *(u16 *)raw_data * multiplier;
                return 0;
        case 4:
                prox_state->human_presence[chan] = *(u32 *)raw_data * multiplier;
                return 0;
        }

        return -EINVAL;
}

/* Parse report which is specific to an usage id*/
static int prox_parse_report(struct platform_device *pdev,
                                struct hid_sensor_hub_device *hsdev,
                                struct prox_state *st)
{
        struct iio_chan_spec *channels = st->channels;
        int index = 0;
        int ret;
        int i;

        for (i = 0; i < MAX_CHANNELS; i++) {
                u32 usage_id = prox_usage_ids[i];

                ret = sensor_hub_input_get_attribute_info(hsdev,
                                                          HID_INPUT_REPORT,
                                                          hsdev->usage,
                                                          usage_id,
                                                          &st->prox_attr[index]);
                if (ret < 0)
                        continue;
                st->channel2usage[index] = usage_id;
                st->scan_mask[0] |= BIT(index);
                channels[index] = prox_channels[i];
                channels[index].scan_index = index;
                prox_adjust_channel_bit_mask(channels, index,
                                             st->prox_attr[index].size);
                dev_dbg(&pdev->dev, "prox %x:%x\n", st->prox_attr[index].index,
                        st->prox_attr[index].report_id);
                st->scale_precision[index] =
                        hid_sensor_format_scale(usage_id, &st->prox_attr[index],
                                                &st->scale_pre_decml[index],
                                                &st->scale_post_decml[index]);
                index++;
        }

        if (!index)
                return ret;

        st->num_channels = index;

        return 0;
}

/* Function to initialize the processing for usage id */
static int hid_prox_probe(struct platform_device *pdev)
{
        struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
        int ret = 0;
        static const char *name = "prox";
        struct iio_dev *indio_dev;
        struct prox_state *prox_state;

        indio_dev = devm_iio_device_alloc(&pdev->dev,
                                sizeof(struct prox_state));
        if (!indio_dev)
                return -ENOMEM;
        platform_set_drvdata(pdev, indio_dev);

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

        ret = hid_sensor_parse_common_attributes(hsdev, hsdev->usage,
                                        &prox_state->common_attributes,
                                        prox_sensitivity_addresses,
                                        ARRAY_SIZE(prox_sensitivity_addresses));
        if (ret) {
                dev_err(&pdev->dev, "failed to setup common attributes\n");
                return ret;
        }

        ret = prox_parse_report(pdev, hsdev, prox_state);
        if (ret) {
                dev_err(&pdev->dev, "failed to setup attributes\n");
                return ret;
        }

        indio_dev->num_channels = prox_state->num_channels;
        indio_dev->channels = prox_state->channels;
        indio_dev->available_scan_masks = prox_state->scan_mask;
        indio_dev->info = &prox_info;
        indio_dev->name = name;
        indio_dev->modes = INDIO_DIRECT_MODE;

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

        ret = hid_sensor_setup_trigger(indio_dev, name,
                                &prox_state->common_attributes);
        if (ret) {
                dev_err(&pdev->dev, "trigger setup failed\n");
                return ret;
        }

        ret = iio_device_register(indio_dev);
        if (ret) {
                dev_err(&pdev->dev, "device register failed\n");
                goto error_remove_trigger;
        }

        prox_state->callbacks.send_event = prox_proc_event;
        prox_state->callbacks.capture_sample = prox_capture_sample;
        prox_state->callbacks.pdev = pdev;
        ret = sensor_hub_register_callback(hsdev, hsdev->usage,
                                           &prox_state->callbacks);
        if (ret < 0) {
                dev_err(&pdev->dev, "callback reg failed\n");
                goto error_iio_unreg;
        }

        return ret;

error_iio_unreg:
        iio_device_unregister(indio_dev);
error_remove_trigger:
        hid_sensor_remove_trigger(indio_dev, &prox_state->common_attributes);
        return ret;
}

/* Function to deinitialize the processing for usage id */
static void hid_prox_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 prox_state *prox_state = iio_priv(indio_dev);

        sensor_hub_remove_callback(hsdev, hsdev->usage);
        iio_device_unregister(indio_dev);
        hid_sensor_remove_trigger(indio_dev, &prox_state->common_attributes);
}

static const struct platform_device_id hid_prox_ids[] = {
        {
                /* Format: HID-SENSOR-usage_id_in_hex_lowercase */
                .name = "HID-SENSOR-200011",
        },
        {
                /* Format: HID-SENSOR-tag-usage_id_in_hex_lowercase */
                .name = "HID-SENSOR-LISS-0226",
        },
        { }
};
MODULE_DEVICE_TABLE(platform, hid_prox_ids);

static struct platform_driver hid_prox_platform_driver = {
        .id_table = hid_prox_ids,
        .driver = {
                .name   = KBUILD_MODNAME,
                .pm     = &hid_sensor_pm_ops,
        },
        .probe          = hid_prox_probe,
        .remove         = hid_prox_remove,
};
module_platform_driver(hid_prox_platform_driver);

MODULE_DESCRIPTION("HID Sensor Proximity");
MODULE_AUTHOR("Archana Patni <archana.patni@intel.com>");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("IIO_HID");