// SPDX-License-Identifier: GPL-2.0-only
/*
 * HID Sensors Driver
 * Copyright (c) 2012, Intel Corporation.
 */

#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
 * @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;
	int ref_cnt;
};

/**
 * struct hid_sensor_hub_callbacks_list - Stores callback list
 * @list:		list head.
 * @usage_id:		usage id for a physical device.
 * @hsdev:		Stored hid instance for current hub 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_obj(*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) {
			ret = hid_set_field(report->field[field_index], i,
					    (__force __s32)cpu_to_le32(*buf32));
			if (ret)
				goto done_proc;

			++buf32;
		}
	}
	if (remaining_bytes) {
		value = 0;
		memcpy(&value, (u8 *)buf32, remaining_bytes);
		ret = hid_set_field(report->field[field_index], i,
				    (__force __s32)cpu_to_le32(value));
		if (ret)
			goto done_proc;
	}
	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 hid_field *field;
	struct sensor_hub_data *data = hid_get_drvdata(hsdev->hdev);
	size_t field_size;
	size_t report_size;
	size_t copied = 0;
	size_t to_copy;
	int ret = 0;
	unsigned int i;

	if (!buffer || buffer_size <= 0)
		return -EINVAL;

	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);

	field = report->field[field_index];

	/* calculate number of bytes required to read this field */
	field_size = DIV_ROUND_UP(field->report_size, 8);
	/* HID core stores each parsed report value in a __s32 slot. */
	if (!field_size || field_size > sizeof(field->value[0])) {
		ret = -EINVAL;
		goto done_proc;
	}
	if (field->report_count > SIZE_MAX / field_size) {
		ret = -EINVAL;
		goto done_proc;
	}

	report_size = field_size * field->report_count;
	report_size = min_t(size_t, report_size, buffer_size);

	for (i = 0; i < field->report_count && copied < report_size; ++i) {
		to_copy = min(field_size, report_size - copied);
		memcpy(&((u8 *)buffer)[copied], &field->value[i], to_copy);
		copied += to_copy;
	}
	ret = copied;

done_proc:
	mutex_unlock(&data->mutex);

	return ret;
}
EXPORT_SYMBOL_GPL(sensor_hub_get_feature);

int sensor_hub_input_attr_read_values(struct hid_sensor_hub_device *hsdev,
				      u32 usage_id, u32 attr_usage_id,
				      u32 report_id,
				      enum sensor_hub_read_flags flag,
				      u32 buffer_size, u8 *buffer)
{
	struct sensor_hub_data *data = hid_get_drvdata(hsdev->hdev);
	struct hid_report *report;
	unsigned long flags;
	long cycles;
	int ret;

	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.max_raw_size = buffer_size;
		hsdev->pending.raw_data = buffer;

		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);
	ret = 0;
	if (flag == SENSOR_HUB_SYNC) {
		cycles = wait_for_completion_interruptible_timeout(&hsdev->pending.ready,
								   HZ * 5);
		if (cycles == 0)
			ret = -ETIMEDOUT;
		else if (cycles < 0)
			ret = cycles;

		hsdev->pending.status = false;
	}
	mutex_unlock(hsdev->mutex_ptr);

	return ret;
}
EXPORT_SYMBOL_GPL(sensor_hub_input_attr_read_values);

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,
					bool is_signed)
{
	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:
			if (is_signed)
				ret_val = *(s8 *)hsdev->pending.raw_data;
			else
				ret_val = *(u8 *)hsdev->pending.raw_data;
			break;
		case 2:
			if (is_signed)
				ret_val = *(s16 *)hsdev->pending.raw_data;
			else
				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->application == 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);

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;
}

/*
 * 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;
	u32 copy_size;
	u32 avail;

	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;
	if (report->id)
		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]->physical :
							     report->field[i]->application,
				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");
			if (hsdev->pending.max_raw_size) {
				if (hsdev->pending.index < hsdev->pending.max_raw_size) {
					avail = hsdev->pending.max_raw_size - hsdev->pending.index;
					copy_size = clamp(sz, 0U, avail);

					memcpy(hsdev->pending.raw_data + hsdev->pending.index,
					       ptr, copy_size);
					hsdev->pending.index += copy_size;
					if (hsdev->pending.index >= hsdev->pending.max_raw_size) {
						hsdev->pending.raw_size = hsdev->pending.index;
						complete(&hsdev->pending.ready);
					}
				}
			} else {
				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 const __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);

	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, HID_CONNECT_DEFAULT | HID_CONNECT_DRIVER);
	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 int sensor_hub_finalize_pending_fn(struct device *dev, void *data)
{
	struct hid_sensor_hub_device *hsdev = dev->platform_data;

	if (hsdev->pending.status)
		complete(&hsdev->pending.ready);

	return 0;
}

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

	hid_dbg(hdev, " hardware removed\n");
	hid_hw_close(hdev);
	hid_hw_stop(hdev);

	spin_lock_irqsave(&data->lock, flags);
	device_for_each_child(&hdev->dev, NULL,
			      sensor_hub_finalize_pending_fn);
	spin_unlock_irqrestore(&data->lock, flags);

	mfd_remove_devices(&hdev->dev);
	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,
	.suspend = pm_ptr(sensor_hub_suspend),
	.resume = pm_ptr(sensor_hub_resume),
	.reset_resume = pm_ptr(sensor_hub_reset_resume),
};
module_hid_driver(sensor_hub_driver);

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