/*
 * HID Sensors Driver
 * Copyright (c) 2012, Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */

#include <linux/device.h>
#include <linux/hid.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/mfd/core.h>
#include <linux/list.h>
#include <linux/hid-sensor-ids.h>
#include <linux/hid-sensor-hub.h>
#include "hid-ids.h"

#define HID_SENSOR_HUB_ENUM_QUIRK       0x01

/**
 * struct sensor_hub_data - Hold a instance data for a HID hub device
 * @hsdev:              Stored hid instance for current hub device.
 * @mutex:              Mutex to serialize synchronous request.
 * @lock:               Spin lock to protect pending request structure.
 * @dyn_callback_list:  Holds callback function
 * @dyn_callback_lock:  spin lock to protect callback list
 * @hid_sensor_hub_client_devs: Stores all MFD cells for a hub instance.
 * @hid_sensor_client_cnt: Number of MFD cells, (no of sensors attached).
 * @ref_cnt:            Number of MFD clients have opened this device
 */
struct sensor_hub_data {
        struct mutex mutex;
        spinlock_t lock;
        struct list_head dyn_callback_list;
        spinlock_t dyn_callback_lock;
        struct mfd_cell *hid_sensor_hub_client_devs;
        int hid_sensor_client_cnt;
        unsigned long quirks;
        int ref_cnt;
};

/**
 * struct hid_sensor_hub_callbacks_list - Stores callback list
 * @list:               list head.
 * @usage_id:           usage id for a physical device.
 * @usage_callback:     Stores registered callback functions.
 * @priv:               Private data for a physical device.
 */
struct hid_sensor_hub_callbacks_list {
        struct list_head list;
        u32 usage_id;
        struct hid_sensor_hub_device *hsdev;
        struct hid_sensor_hub_callbacks *usage_callback;
        void *priv;
};

static struct hid_report *sensor_hub_report(int id, struct hid_device *hdev,
                                                int dir)
{
        struct hid_report *report;

        list_for_each_entry(report, &hdev->report_enum[dir].report_list, list) {
                if (report->id == id)
                        return report;
        }
        hid_warn(hdev, "No report with id 0x%x found\n", id);

        return NULL;
}

static int sensor_hub_get_physical_device_count(struct hid_device *hdev)
{
        int i;
        int count = 0;

        for (i = 0; i < hdev->maxcollection; ++i) {
                struct hid_collection *collection = &hdev->collection[i];
                if (collection->type == HID_COLLECTION_PHYSICAL ||
                    collection->type == HID_COLLECTION_APPLICATION)
                        ++count;
        }

        return count;
}

static void sensor_hub_fill_attr_info(
                struct hid_sensor_hub_attribute_info *info,
                s32 index, s32 report_id, struct hid_field *field)
{
        info->index = index;
        info->report_id = report_id;
        info->units = field->unit;
        info->unit_expo = field->unit_exponent;
        info->size = (field->report_size * field->report_count)/8;
        info->logical_minimum = field->logical_minimum;
        info->logical_maximum = field->logical_maximum;
}

static struct hid_sensor_hub_callbacks *sensor_hub_get_callback(
                                        struct hid_device *hdev,
                                        u32 usage_id,
                                        int collection_index,
                                        struct hid_sensor_hub_device **hsdev,
                                        void **priv)
{
        struct hid_sensor_hub_callbacks_list *callback;
        struct sensor_hub_data *pdata = hid_get_drvdata(hdev);
        unsigned long flags;

        spin_lock_irqsave(&pdata->dyn_callback_lock, flags);
        list_for_each_entry(callback, &pdata->dyn_callback_list, list)
                if ((callback->usage_id == usage_id ||
                     callback->usage_id == HID_USAGE_SENSOR_COLLECTION) &&
                        (collection_index >=
                                callback->hsdev->start_collection_index) &&
                        (collection_index <
                                callback->hsdev->end_collection_index)) {
                        *priv = callback->priv;
                        *hsdev = callback->hsdev;
                        spin_unlock_irqrestore(&pdata->dyn_callback_lock,
                                               flags);
                        return callback->usage_callback;
                }
        spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);

        return NULL;
}

int sensor_hub_register_callback(struct hid_sensor_hub_device *hsdev,
                        u32 usage_id,
                        struct hid_sensor_hub_callbacks *usage_callback)
{
        struct hid_sensor_hub_callbacks_list *callback;
        struct sensor_hub_data *pdata = hid_get_drvdata(hsdev->hdev);
        unsigned long flags;

        spin_lock_irqsave(&pdata->dyn_callback_lock, flags);
        list_for_each_entry(callback, &pdata->dyn_callback_list, list)
                if (callback->usage_id == usage_id &&
                                                callback->hsdev == hsdev) {
                        spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);
                        return -EINVAL;
                }
        callback = kzalloc(sizeof(*callback), GFP_ATOMIC);
        if (!callback) {
                spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);
                return -ENOMEM;
        }
        callback->hsdev = hsdev;
        callback->usage_callback = usage_callback;
        callback->usage_id = usage_id;
        callback->priv = NULL;
        /*
         * If there is a handler registered for the collection type, then
         * it will handle all reports for sensors in this collection. If
         * there is also an individual sensor handler registration, then
         * we want to make sure that the reports are directed to collection
         * handler, as this may be a fusion sensor. So add collection handlers
         * to the beginning of the list, so that they are matched first.
         */
        if (usage_id == HID_USAGE_SENSOR_COLLECTION)
                list_add(&callback->list, &pdata->dyn_callback_list);
        else
                list_add_tail(&callback->list, &pdata->dyn_callback_list);
        spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);

        return 0;
}
EXPORT_SYMBOL_GPL(sensor_hub_register_callback);

int sensor_hub_remove_callback(struct hid_sensor_hub_device *hsdev,
                                u32 usage_id)
{
        struct hid_sensor_hub_callbacks_list *callback;
        struct sensor_hub_data *pdata = hid_get_drvdata(hsdev->hdev);
        unsigned long flags;

        spin_lock_irqsave(&pdata->dyn_callback_lock, flags);
        list_for_each_entry(callback, &pdata->dyn_callback_list, list)
                if (callback->usage_id == usage_id &&
                                                callback->hsdev == hsdev) {
                        list_del(&callback->list);
                        kfree(callback);
                        break;
                }
        spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);

        return 0;
}
EXPORT_SYMBOL_GPL(sensor_hub_remove_callback);

int sensor_hub_set_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
                           u32 field_index, int buffer_size, void *buffer)
{
        struct hid_report *report;
        struct sensor_hub_data *data = hid_get_drvdata(hsdev->hdev);
        __s32 *buf32 = buffer;
        int i = 0;
        int remaining_bytes;
        __s32 value;
        int ret = 0;

        mutex_lock(&data->mutex);
        report = sensor_hub_report(report_id, hsdev->hdev, HID_FEATURE_REPORT);
        if (!report || (field_index >= report->maxfield)) {
                ret = -EINVAL;
                goto done_proc;
        }

        remaining_bytes = buffer_size % sizeof(__s32);
        buffer_size = buffer_size / sizeof(__s32);
        if (buffer_size) {
                for (i = 0; i < buffer_size; ++i) {
                        hid_set_field(report->field[field_index], i,
                                      (__force __s32)cpu_to_le32(*buf32));
                        ++buf32;
                }
        }
        if (remaining_bytes) {
                value = 0;
                memcpy(&value, (u8 *)buf32, remaining_bytes);
                hid_set_field(report->field[field_index], i,
                              (__force __s32)cpu_to_le32(value));
        }
        hid_hw_request(hsdev->hdev, report, HID_REQ_SET_REPORT);
        hid_hw_wait(hsdev->hdev);

done_proc:
        mutex_unlock(&data->mutex);

        return ret;
}
EXPORT_SYMBOL_GPL(sensor_hub_set_feature);

int sensor_hub_get_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
                           u32 field_index, int buffer_size, void *buffer)
{
        struct hid_report *report;
        struct sensor_hub_data *data = hid_get_drvdata(hsdev->hdev);
        int report_size;
        int ret = 0;
        u8 *val_ptr;
        int buffer_index = 0;
        int i;

        memset(buffer, 0, buffer_size);

        mutex_lock(&data->mutex);
        report = sensor_hub_report(report_id, hsdev->hdev, HID_FEATURE_REPORT);
        if (!report || (field_index >= report->maxfield) ||
            report->field[field_index]->report_count < 1) {
                ret = -EINVAL;
                goto done_proc;
        }
        hid_hw_request(hsdev->hdev, report, HID_REQ_GET_REPORT);
        hid_hw_wait(hsdev->hdev);

        /* calculate number of bytes required to read this field */
        report_size = DIV_ROUND_UP(report->field[field_index]->report_size,
                                   8) *
                                   report->field[field_index]->report_count;
        if (!report_size) {
                ret = -EINVAL;
                goto done_proc;
        }
        ret = min(report_size, buffer_size);

        val_ptr = (u8 *)report->field[field_index]->value;
        for (i = 0; i < report->field[field_index]->report_count; ++i) {
                if (buffer_index >= ret)
                        break;

                memcpy(&((u8 *)buffer)[buffer_index], val_ptr,
                       report->field[field_index]->report_size / 8);
                val_ptr += sizeof(__s32);
                buffer_index += (report->field[field_index]->report_size / 8);
        }

done_proc:
        mutex_unlock(&data->mutex);

        return ret;
}
EXPORT_SYMBOL_GPL(sensor_hub_get_feature);


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)
{
        struct sensor_hub_data *data = hid_get_drvdata(hsdev->hdev);
        unsigned long flags;
        struct hid_report *report;
        int ret_val = 0;

        report = sensor_hub_report(report_id, hsdev->hdev,
                                   HID_INPUT_REPORT);
        if (!report)
                return -EINVAL;

        mutex_lock(hsdev->mutex_ptr);
        if (flag == SENSOR_HUB_SYNC) {
                memset(&hsdev->pending, 0, sizeof(hsdev->pending));
                init_completion(&hsdev->pending.ready);
                hsdev->pending.usage_id = usage_id;
                hsdev->pending.attr_usage_id = attr_usage_id;
                hsdev->pending.raw_size = 0;

                spin_lock_irqsave(&data->lock, flags);
                hsdev->pending.status = true;
                spin_unlock_irqrestore(&data->lock, flags);
        }
        mutex_lock(&data->mutex);
        hid_hw_request(hsdev->hdev, report, HID_REQ_GET_REPORT);
        mutex_unlock(&data->mutex);
        if (flag == SENSOR_HUB_SYNC) {
                wait_for_completion_interruptible_timeout(
                                                &hsdev->pending.ready, HZ*5);
                switch (hsdev->pending.raw_size) {
                case 1:
                        ret_val = *(u8 *)hsdev->pending.raw_data;
                        break;
                case 2:
                        ret_val = *(u16 *)hsdev->pending.raw_data;
                        break;
                case 4:
                        ret_val = *(u32 *)hsdev->pending.raw_data;
                        break;
                default:
                        ret_val = 0;
                }
                kfree(hsdev->pending.raw_data);
                hsdev->pending.status = false;
        }
        mutex_unlock(hsdev->mutex_ptr);

        return ret_val;
}
EXPORT_SYMBOL_GPL(sensor_hub_input_attr_get_raw_value);

int hid_sensor_get_usage_index(struct hid_sensor_hub_device *hsdev,
                                u32 report_id, int field_index, u32 usage_id)
{
        struct hid_report *report;
        struct hid_field *field;
        int i;

        report = sensor_hub_report(report_id, hsdev->hdev, HID_FEATURE_REPORT);
        if (!report || (field_index >= report->maxfield))
                goto done_proc;

        field = report->field[field_index];
        for (i = 0; i < field->maxusage; ++i) {
                if (field->usage[i].hid == usage_id)
                        return field->usage[i].usage_index;
        }

done_proc:
        return -EINVAL;
}
EXPORT_SYMBOL_GPL(hid_sensor_get_usage_index);

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)
{
        int ret = -1;
        int i;
        struct hid_report *report;
        struct hid_field *field;
        struct hid_report_enum *report_enum;
        struct hid_device *hdev = hsdev->hdev;

        /* Initialize with defaults */
        info->usage_id = usage_id;
        info->attrib_id = attr_usage_id;
        info->report_id = -1;
        info->index = -1;
        info->units = -1;
        info->unit_expo = -1;

        report_enum = &hdev->report_enum[type];
        list_for_each_entry(report, &report_enum->report_list, list) {
                for (i = 0; i < report->maxfield; ++i) {
                        field = report->field[i];
                        if (field->maxusage) {
                                if (field->physical == usage_id &&
                                        (field->logical == attr_usage_id ||
                                        field->usage[0].hid ==
                                                        attr_usage_id) &&
                                        (field->usage[0].collection_index >=
                                        hsdev->start_collection_index) &&
                                        (field->usage[0].collection_index <
                                        hsdev->end_collection_index)) {

                                        sensor_hub_fill_attr_info(info, i,
                                                                report->id,
                                                                field);
                                        ret = 0;
                                        break;
                                }
                        }
                }

        }

        return ret;
}
EXPORT_SYMBOL_GPL(sensor_hub_input_get_attribute_info);

#ifdef CONFIG_PM
static int sensor_hub_suspend(struct hid_device *hdev, pm_message_t message)
{
        struct sensor_hub_data *pdata = hid_get_drvdata(hdev);
        struct hid_sensor_hub_callbacks_list *callback;
        unsigned long flags;

        hid_dbg(hdev, " sensor_hub_suspend\n");
        spin_lock_irqsave(&pdata->dyn_callback_lock, flags);
        list_for_each_entry(callback, &pdata->dyn_callback_list, list) {
                if (callback->usage_callback->suspend)
                        callback->usage_callback->suspend(
                                        callback->hsdev, callback->priv);
        }
        spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);

        return 0;
}

static int sensor_hub_resume(struct hid_device *hdev)
{
        struct sensor_hub_data *pdata = hid_get_drvdata(hdev);
        struct hid_sensor_hub_callbacks_list *callback;
        unsigned long flags;

        hid_dbg(hdev, " sensor_hub_resume\n");
        spin_lock_irqsave(&pdata->dyn_callback_lock, flags);
        list_for_each_entry(callback, &pdata->dyn_callback_list, list) {
                if (callback->usage_callback->resume)
                        callback->usage_callback->resume(
                                        callback->hsdev, callback->priv);
        }
        spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);

        return 0;
}

static int sensor_hub_reset_resume(struct hid_device *hdev)
{
        return 0;
}
#endif

/*
 * Handle raw report as sent by device
 */
static int sensor_hub_raw_event(struct hid_device *hdev,
                struct hid_report *report, u8 *raw_data, int size)
{
        int i;
        u8 *ptr;
        int sz;
        struct sensor_hub_data *pdata = hid_get_drvdata(hdev);
        unsigned long flags;
        struct hid_sensor_hub_callbacks *callback = NULL;
        struct hid_collection *collection = NULL;
        void *priv = NULL;
        struct hid_sensor_hub_device *hsdev = NULL;

        hid_dbg(hdev, "sensor_hub_raw_event report id:0x%x size:%d type:%d\n",
                         report->id, size, report->type);
        hid_dbg(hdev, "maxfield:%d\n", report->maxfield);
        if (report->type != HID_INPUT_REPORT)
                return 1;

        ptr = raw_data;
        ptr++; /* Skip report id */

        spin_lock_irqsave(&pdata->lock, flags);

        for (i = 0; i < report->maxfield; ++i) {
                hid_dbg(hdev, "%d collection_index:%x hid:%x sz:%x\n",
                                i, report->field[i]->usage->collection_index,
                                report->field[i]->usage->hid,
                                (report->field[i]->report_size *
                                        report->field[i]->report_count)/8);
                sz = (report->field[i]->report_size *
                                        report->field[i]->report_count)/8;
                collection = &hdev->collection[
                                report->field[i]->usage->collection_index];
                hid_dbg(hdev, "collection->usage %x\n",
                                        collection->usage);

                callback = sensor_hub_get_callback(hdev,
                                report->field[i]->physical,
                                report->field[i]->usage[0].collection_index,
                                &hsdev, &priv);
                if (!callback) {
                        ptr += sz;
                        continue;
                }
                if (hsdev->pending.status && (hsdev->pending.attr_usage_id ==
                                              report->field[i]->usage->hid ||
                                              hsdev->pending.attr_usage_id ==
                                              report->field[i]->logical)) {
                        hid_dbg(hdev, "data was pending ...\n");
                        hsdev->pending.raw_data = kmemdup(ptr, sz, GFP_ATOMIC);
                        if (hsdev->pending.raw_data)
                                hsdev->pending.raw_size = sz;
                        else
                                hsdev->pending.raw_size = 0;
                        complete(&hsdev->pending.ready);
                }
                if (callback->capture_sample) {
                        if (report->field[i]->logical)
                                callback->capture_sample(hsdev,
                                        report->field[i]->logical, sz, ptr,
                                        callback->pdev);
                        else
                                callback->capture_sample(hsdev,
                                        report->field[i]->usage->hid, sz, ptr,
                                        callback->pdev);
                }
                ptr += sz;
        }
        if (callback && collection && callback->send_event)
                callback->send_event(hsdev, collection->usage,
                                callback->pdev);
        spin_unlock_irqrestore(&pdata->lock, flags);

        return 1;
}

int sensor_hub_device_open(struct hid_sensor_hub_device *hsdev)
{
        int ret = 0;
        struct sensor_hub_data *data =  hid_get_drvdata(hsdev->hdev);

        mutex_lock(&data->mutex);
        if (!data->ref_cnt) {
                ret = hid_hw_open(hsdev->hdev);
                if (ret) {
                        hid_err(hsdev->hdev, "failed to open hid device\n");
                        mutex_unlock(&data->mutex);
                        return ret;
                }
        }
        data->ref_cnt++;
        mutex_unlock(&data->mutex);

        return ret;
}
EXPORT_SYMBOL_GPL(sensor_hub_device_open);

void sensor_hub_device_close(struct hid_sensor_hub_device *hsdev)
{
        struct sensor_hub_data *data =  hid_get_drvdata(hsdev->hdev);

        mutex_lock(&data->mutex);
        data->ref_cnt--;
        if (!data->ref_cnt)
                hid_hw_close(hsdev->hdev);
        mutex_unlock(&data->mutex);
}
EXPORT_SYMBOL_GPL(sensor_hub_device_close);

static __u8 *sensor_hub_report_fixup(struct hid_device *hdev, __u8 *rdesc,
                unsigned int *rsize)
{
        /*
         * Checks if the report descriptor of Thinkpad Helix 2 has a logical
         * minimum for magnetic flux axis greater than the maximum.
         */
        if (hdev->product == USB_DEVICE_ID_TEXAS_INSTRUMENTS_LENOVO_YOGA &&
                *rsize == 2558 && rdesc[913] == 0x17 && rdesc[914] == 0x40 &&
                rdesc[915] == 0x81 && rdesc[916] == 0x08 &&
                rdesc[917] == 0x00 && rdesc[918] == 0x27 &&
                rdesc[921] == 0x07 && rdesc[922] == 0x00) {
                /* Sets negative logical minimum for mag x, y and z */
                rdesc[914] = rdesc[935] = rdesc[956] = 0xc0;
                rdesc[915] = rdesc[936] = rdesc[957] = 0x7e;
                rdesc[916] = rdesc[937] = rdesc[958] = 0xf7;
                rdesc[917] = rdesc[938] = rdesc[959] = 0xff;
        }

        return rdesc;
}

static int sensor_hub_probe(struct hid_device *hdev,
                                const struct hid_device_id *id)
{
        int ret;
        struct sensor_hub_data *sd;
        int i;
        char *name;
        int dev_cnt;
        struct hid_sensor_hub_device *hsdev;
        struct hid_sensor_hub_device *last_hsdev = NULL;
        struct hid_sensor_hub_device *collection_hsdev = NULL;

        sd = devm_kzalloc(&hdev->dev, sizeof(*sd), GFP_KERNEL);
        if (!sd) {
                hid_err(hdev, "cannot allocate Sensor data\n");
                return -ENOMEM;
        }

        hid_set_drvdata(hdev, sd);
        sd->quirks = id->driver_data;

        spin_lock_init(&sd->lock);
        spin_lock_init(&sd->dyn_callback_lock);
        mutex_init(&sd->mutex);
        ret = hid_parse(hdev);
        if (ret) {
                hid_err(hdev, "parse failed\n");
                return ret;
        }
        INIT_LIST_HEAD(&hdev->inputs);

        ret = hid_hw_start(hdev, 0);
        if (ret) {
                hid_err(hdev, "hw start failed\n");
                return ret;
        }
        INIT_LIST_HEAD(&sd->dyn_callback_list);
        sd->hid_sensor_client_cnt = 0;

        dev_cnt = sensor_hub_get_physical_device_count(hdev);
        if (dev_cnt > HID_MAX_PHY_DEVICES) {
                hid_err(hdev, "Invalid Physical device count\n");
                ret = -EINVAL;
                goto err_stop_hw;
        }
        sd->hid_sensor_hub_client_devs = devm_kcalloc(&hdev->dev,
                                                      dev_cnt,
                                                      sizeof(struct mfd_cell),
                                                      GFP_KERNEL);
        if (sd->hid_sensor_hub_client_devs == NULL) {
                hid_err(hdev, "Failed to allocate memory for mfd cells\n");
                ret = -ENOMEM;
                goto err_stop_hw;
        }

        for (i = 0; i < hdev->maxcollection; ++i) {
                struct hid_collection *collection = &hdev->collection[i];

                if (collection->type == HID_COLLECTION_PHYSICAL ||
                    collection->type == HID_COLLECTION_APPLICATION) {

                        hsdev = devm_kzalloc(&hdev->dev, sizeof(*hsdev),
                                             GFP_KERNEL);
                        if (!hsdev) {
                                hid_err(hdev, "cannot allocate hid_sensor_hub_device\n");
                                ret = -ENOMEM;
                                goto err_stop_hw;
                        }
                        hsdev->hdev = hdev;
                        hsdev->vendor_id = hdev->vendor;
                        hsdev->product_id = hdev->product;
                        hsdev->usage = collection->usage;
                        hsdev->mutex_ptr = devm_kzalloc(&hdev->dev,
                                                        sizeof(struct mutex),
                                                        GFP_KERNEL);
                        if (!hsdev->mutex_ptr) {
                                ret = -ENOMEM;
                                goto err_stop_hw;
                        }
                        mutex_init(hsdev->mutex_ptr);
                        hsdev->start_collection_index = i;
                        if (last_hsdev)
                                last_hsdev->end_collection_index = i;
                        last_hsdev = hsdev;
                        name = devm_kasprintf(&hdev->dev, GFP_KERNEL,
                                              "HID-SENSOR-%x",
                                              collection->usage);
                        if (name == NULL) {
                                hid_err(hdev, "Failed MFD device name\n");
                                ret = -ENOMEM;
                                goto err_stop_hw;
                        }
                        sd->hid_sensor_hub_client_devs[
                                sd->hid_sensor_client_cnt].name = name;
                        sd->hid_sensor_hub_client_devs[
                                sd->hid_sensor_client_cnt].platform_data =
                                                        hsdev;
                        sd->hid_sensor_hub_client_devs[
                                sd->hid_sensor_client_cnt].pdata_size =
                                                        sizeof(*hsdev);
                        hid_dbg(hdev, "Adding %s:%d\n", name,
                                        hsdev->start_collection_index);
                        sd->hid_sensor_client_cnt++;
                        if (collection_hsdev)
                                collection_hsdev->end_collection_index = i;
                        if (collection->type == HID_COLLECTION_APPLICATION &&
                            collection->usage == HID_USAGE_SENSOR_COLLECTION)
                                collection_hsdev = hsdev;
                }
        }
        if (last_hsdev)
                last_hsdev->end_collection_index = i;
        if (collection_hsdev)
                collection_hsdev->end_collection_index = i;

        ret = mfd_add_hotplug_devices(&hdev->dev,
                        sd->hid_sensor_hub_client_devs,
                        sd->hid_sensor_client_cnt);
        if (ret < 0)
                goto err_stop_hw;

        return ret;

err_stop_hw:
        hid_hw_stop(hdev);

        return ret;
}

static void sensor_hub_remove(struct hid_device *hdev)
{
        struct sensor_hub_data *data = hid_get_drvdata(hdev);
        unsigned long flags;
        int i;

        hid_dbg(hdev, " hardware removed\n");
        hid_hw_close(hdev);
        hid_hw_stop(hdev);
        spin_lock_irqsave(&data->lock, flags);
        for (i = 0; i < data->hid_sensor_client_cnt; ++i) {
                struct hid_sensor_hub_device *hsdev =
                        data->hid_sensor_hub_client_devs[i].platform_data;
                if (hsdev->pending.status)
                        complete(&hsdev->pending.ready);
        }
        spin_unlock_irqrestore(&data->lock, flags);
        mfd_remove_devices(&hdev->dev);
        hid_set_drvdata(hdev, NULL);
        mutex_destroy(&data->mutex);
}

static const struct hid_device_id sensor_hub_devices[] = {
        { HID_DEVICE(HID_BUS_ANY, HID_GROUP_SENSOR_HUB, HID_ANY_ID,
                     HID_ANY_ID) },
        { }
};
MODULE_DEVICE_TABLE(hid, sensor_hub_devices);

static struct hid_driver sensor_hub_driver = {
        .name = "hid-sensor-hub",
        .id_table = sensor_hub_devices,
        .probe = sensor_hub_probe,
        .remove = sensor_hub_remove,
        .raw_event = sensor_hub_raw_event,
        .report_fixup = sensor_hub_report_fixup,
#ifdef CONFIG_PM
        .suspend = sensor_hub_suspend,
        .resume = sensor_hub_resume,
        .reset_resume = sensor_hub_reset_resume,
#endif
};
module_hid_driver(sensor_hub_driver);

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