Merge branch 'for-4.1/sensor-hub' into for-linus

Conflicts: drivers/iio/common/hid-sensors/hid-sensor-trigger.c include/linux/hid-sensor-hub.h
2026-05-01 15:00:59 -07:00 · 2015-04-13 23:43:34 +02:00
parent 05f6d02521 b2eafd7282
commit 2e455c27bd
17 changed files with 1153 additions and 109 deletions
@@ -138,3 +138,87 @@ accelerometer wants to poll X axis value, then it can call this function with
 the usage id of X axis. HID sensors can provide events, so this is not necessary
 to poll for any field. If there is some new sample, the core driver will call
 registered callback function to process the sample.
+
+
+----------
+
+HID Custom and generic Sensors
+
+HID Sensor specification defines two special sensor usage types. Since they
+don't represent a standard sensor, it is not possible to define using Linux IIO
+type interfaces.
+The purpose of these sensors is to extend the functionality or provide a
+way to obfuscate the data being communicated by a sensor. Without knowing the
+mapping between the data and its encapsulated form, it is difficult for
+an application/driver to determine what data is being communicated by the sensor.
+This allows some differentiating use cases, where vendor can provide applications.
+Some common use cases are debug other sensors or to provide some events like
+keyboard attached/detached or lid open/close.
+
+To allow application to utilize these sensors, here they are exported uses sysfs
+attribute groups, attributes and misc device interface.
+
+An example of this representation on sysfs:
+/sys/devices/pci0000:00/INT33C2:00/i2c-0/i2c-INT33D1:00/0018:8086:09FA.0001/HID-SENSOR-2000e1.6.auto$ tree -R
+.
+????????? enable_sensor
+????????? feature-0-200316
+??????? ????????? feature-0-200316-maximum
+??????? ????????? feature-0-200316-minimum
+??????? ????????? feature-0-200316-name
+??????? ????????? feature-0-200316-size
+??????? ????????? feature-0-200316-unit-expo
+??????? ????????? feature-0-200316-units
+??????? ????????? feature-0-200316-value
+????????? feature-1-200201
+??????? ????????? feature-1-200201-maximum
+??????? ????????? feature-1-200201-minimum
+??????? ????????? feature-1-200201-name
+??????? ????????? feature-1-200201-size
+??????? ????????? feature-1-200201-unit-expo
+??????? ????????? feature-1-200201-units
+??????? ????????? feature-1-200201-value
+????????? input-0-200201
+??????? ????????? input-0-200201-maximum
+??????? ????????? input-0-200201-minimum
+??????? ????????? input-0-200201-name
+??????? ????????? input-0-200201-size
+??????? ????????? input-0-200201-unit-expo
+??????? ????????? input-0-200201-units
+??????? ????????? input-0-200201-value
+????????? input-1-200202
+??????? ????????? input-1-200202-maximum
+??????? ????????? input-1-200202-minimum
+??????? ????????? input-1-200202-name
+??????? ????????? input-1-200202-size
+??????? ????????? input-1-200202-unit-expo
+??????? ????????? input-1-200202-units
+??????? ????????? input-1-200202-value
+
+Here there is a custom sensors with four fields, two feature and two inputs.
+Each field is represented by a set of attributes. All fields except the "value"
+are read only. The value field is a RW field.
+Example
+/sys/bus/platform/devices/HID-SENSOR-2000e1.6.auto/feature-0-200316$ grep -r . *
+feature-0-200316-maximum:6
+feature-0-200316-minimum:0
+feature-0-200316-name:property-reporting-state
+feature-0-200316-size:1
+feature-0-200316-unit-expo:0
+feature-0-200316-units:25
+feature-0-200316-value:1
+
+How to enable such sensor?
+By default sensor can be power gated. To enable sysfs attribute "enable" can be
+used.
+$ echo 1 > enable_sensor
+
+Once enabled and powered on, sensor can report value using HID reports.
+These reports are pushed using misc device interface in a FIFO order.
+/dev$ tree | grep HID-SENSOR-2000e1.6.auto
+??????? ????????? 10:53 -> ../HID-SENSOR-2000e1.6.auto
+????????? HID-SENSOR-2000e1.6.auto
+
+Each reports can be of variable length preceded by a header. This header
+consist of a 32 bit usage id, 64 bit time stamp and 32 bit length field of raw
+data.
@@ -878,6 +878,21 @@ config HID_SENSOR_HUB
 	  for events and handle data streams. Each sensor driver can format
 	  data and present to user mode using input or IIO interface.

+config HID_SENSOR_CUSTOM_SENSOR
+	tristate "HID Sensors hub custom sensor support"
+	depends on HID_SENSOR_HUB
+	default n
+	---help---
+	  HID Sensor hub specification allows definition of some custom and
+	  generic sensors. Unlike other HID sensors, they can't be exported
+	  via Linux IIO because of custom fields. This is up to the manufacturer
+	  to decide how to interpret these special sensor ids and process in
+	  the user space. Currently some manufacturers are using these ids for
+	  sensor calibration and debugging other sensors. Manufacturers
+	  should't use these special custom sensor ids to export any of the
+	  standard sensors.
+	  Select this config option for custom/generic sensor support.
+
 endmenu

 endif # HID
@@ -100,6 +100,7 @@ obj-$(CONFIG_HID_WACOM)		+= wacom.o
 obj-$(CONFIG_HID_WALTOP)	+= hid-waltop.o
 obj-$(CONFIG_HID_WIIMOTE)	+= hid-wiimote.o
 obj-$(CONFIG_HID_SENSOR_HUB)	+= hid-sensor-hub.o
+obj-$(CONFIG_HID_SENSOR_CUSTOM_SENSOR)	+= hid-sensor-custom.o

 obj-$(CONFIG_USB_HID)		+= usbhid/
 obj-$(CONFIG_USB_MOUSE)		+= usbhid/
@@ -28,30 +28,11 @@

 #define HID_SENSOR_HUB_ENUM_QUIRK	0x01

-/**
- * struct sensor_hub_pending - Synchronous read pending information
- * @status:		Pending status true/false.
- * @ready:		Completion synchronization data.
- * @usage_id:		Usage id for physical device, E.g. Gyro usage id.
- * @attr_usage_id:	Usage Id of a field, E.g. X-AXIS for a gyro.
- * @raw_size:		Response size for a read request.
- * @raw_data:		Place holder for received response.
- */
-struct sensor_hub_pending {
-	bool status;
-	struct completion ready;
-	u32 usage_id;
-	u32 attr_usage_id;
-	int raw_size;
-	u8  *raw_data;
-};
-
 /**
 * 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.
- * @pending:		Holds information of pending sync read request.
 * @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.
@@ -61,7 +42,6 @@ struct sensor_hub_pending {
 struct sensor_hub_data {
 	struct mutex mutex;
 	spinlock_t lock;
-	struct sensor_hub_pending pending;
 	struct list_head dyn_callback_list;
 	spinlock_t dyn_callback_lock;
 	struct mfd_cell *hid_sensor_hub_client_devs;
@@ -106,7 +86,8 @@ static int sensor_hub_get_physical_device_count(struct hid_device *hdev)

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

@@ -139,7 +120,8 @@ static struct hid_sensor_hub_callbacks *sensor_hub_get_callback(

 	spin_lock_irqsave(&pdata->dyn_callback_lock, flags);
 	list_for_each_entry(callback, &pdata->dyn_callback_list, list)
-		if (callback->usage_id == usage_id &&
+		if ((callback->usage_id == usage_id ||
+		     callback->usage_id == HID_USAGE_SENSOR_COLLECTION) &&
 			(collection_index >=
 				callback->hsdev->start_collection_index) &&
 			(collection_index <
@@ -179,7 +161,18 @@ int sensor_hub_register_callback(struct hid_sensor_hub_device *hsdev,
 	callback->usage_callback = usage_callback;
 	callback->usage_id = usage_id;
 	callback->priv = NULL;
-	list_add_tail(&callback->list, &pdata->dyn_callback_list);
+	/*
+	 * 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;
@@ -208,10 +201,14 @@ int sensor_hub_remove_callback(struct hid_sensor_hub_device *hsdev,
 EXPORT_SYMBOL_GPL(sensor_hub_remove_callback);

 int sensor_hub_set_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
-				u32 field_index, s32 value)
+			   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);
@@ -220,7 +217,21 @@ int sensor_hub_set_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
 		ret = -EINVAL;
 		goto done_proc;
 	}
-	hid_set_field(report->field[field_index], 0, value);
+
+	remaining_bytes = do_div(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);

@@ -232,10 +243,11 @@ done_proc:
 EXPORT_SYMBOL_GPL(sensor_hub_set_feature);

 int sensor_hub_get_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
-				u32 field_index, s32 *value)
+			   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;

 	mutex_lock(&data->mutex);
@@ -247,7 +259,17 @@ int sensor_hub_get_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
 	}
 	hid_hw_request(hsdev->hdev, report, HID_REQ_GET_REPORT);
 	hid_hw_wait(hsdev->hdev);
-	*value = report->field[field_index]->value[0];
+
+	/* 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);
+	memcpy(buffer, report->field[field_index]->value, ret);

 done_proc:
 	mutex_unlock(&data->mutex);
@@ -259,47 +281,54 @@ 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)
+					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;

-	mutex_lock(&data->mutex);
-	memset(&data->pending, 0, sizeof(data->pending));
-	init_completion(&data->pending.ready);
-	data->pending.usage_id = usage_id;
-	data->pending.attr_usage_id = attr_usage_id;
-	data->pending.raw_size = 0;
-
-	spin_lock_irqsave(&data->lock, flags);
-	data->pending.status = true;
-	spin_unlock_irqrestore(&data->lock, flags);
-	report = sensor_hub_report(report_id, hsdev->hdev, HID_INPUT_REPORT);
+	report = sensor_hub_report(report_id, hsdev->hdev,
+				   HID_INPUT_REPORT);
 	if (!report)
-		goto err_free;
+		return -EINVAL;

-	hid_hw_request(hsdev->hdev, report, HID_REQ_GET_REPORT);
-	wait_for_completion_interruptible_timeout(&data->pending.ready, HZ*5);
-	switch (data->pending.raw_size) {
-	case 1:
-		ret_val = *(u8 *)data->pending.raw_data;
-		break;
-	case 2:
-		ret_val = *(u16 *)data->pending.raw_data;
-		break;
-	case 4:
-		ret_val = *(u32 *)data->pending.raw_data;
-		break;
-	default:
-		ret_val = 0;
+	mutex_lock(&hsdev->mutex);
+	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);
 	}
-	kfree(data->pending.raw_data);
-
-err_free:
-	data->pending.status = false;
+	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);

 	return ret_val;
 }
@@ -455,16 +484,6 @@ static int sensor_hub_raw_event(struct hid_device *hdev,
 					report->field[i]->report_count)/8);
 		sz = (report->field[i]->report_size *
 					report->field[i]->report_count)/8;
-		if (pdata->pending.status && pdata->pending.attr_usage_id ==
-				report->field[i]->usage->hid) {
-			hid_dbg(hdev, "data was pending ...\n");
-			pdata->pending.raw_data = kmemdup(ptr, sz, GFP_ATOMIC);
-			if (pdata->pending.raw_data)
-				pdata->pending.raw_size = sz;
-			else
-				pdata->pending.raw_size = 0;
-			complete(&pdata->pending.ready);
-		}
 		collection = &hdev->collection[
 				report->field[i]->usage->collection_index];
 		hid_dbg(hdev, "collection->usage %x\n",
@@ -474,8 +493,23 @@ static int sensor_hub_raw_event(struct hid_device *hdev,
 				report->field[i]->physical,
 				report->field[i]->usage[0].collection_index,
 				&hsdev, &priv);
-
-		if (callback && callback->capture_sample) {
+		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,
@@ -572,6 +606,7 @@ static int sensor_hub_probe(struct hid_device *hdev,
 	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) {
@@ -618,7 +653,8 @@ static int sensor_hub_probe(struct hid_device *hdev,
 	for (i = 0; i < hdev->maxcollection; ++i) {
 		struct hid_collection *collection = &hdev->collection[i];

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

 			hsdev = devm_kzalloc(&hdev->dev, sizeof(*hsdev),
 					     GFP_KERNEL);
@@ -630,6 +666,8 @@ static int sensor_hub_probe(struct hid_device *hdev,
 			hsdev->hdev = hdev;
 			hsdev->vendor_id = hdev->vendor;
 			hsdev->product_id = hdev->product;
+			hsdev->usage = collection->usage;
+			mutex_init(&hsdev->mutex);
 			hsdev->start_collection_index = i;
 			if (last_hsdev)
 				last_hsdev->end_collection_index = i;
@@ -653,10 +691,17 @@ static int sensor_hub_probe(struct hid_device *hdev,
 			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,
@@ -676,13 +721,18 @@ 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);
-	if (data->pending.status)
-		complete(&data->pending.ready);
+	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);
@@ -123,7 +123,8 @@ static int accel_3d_read_raw(struct iio_dev *indio_dev,
 			*val = sensor_hub_input_attr_get_raw_value(
 					accel_state->common_attributes.hsdev,
 					HID_USAGE_SENSOR_ACCEL_3D, address,
-					report_id);
+					report_id,
+					SENSOR_HUB_SYNC);
 		else {
 			*val = 0;
 			hid_sensor_power_state(&accel_state->common_attributes,
@@ -153,8 +153,8 @@ s32 hid_sensor_read_poll_value(struct hid_sensor_common *st)
 	int ret;

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

 	if (ret < 0 || value < 0) {
 		return -EINVAL;
@@ -174,8 +174,8 @@ int hid_sensor_read_samp_freq_value(struct hid_sensor_common *st,
 	int ret;

 	ret = sensor_hub_get_feature(st->hsdev,
-		st->poll.report_id,
-		st->poll.index, &value);
+				     st->poll.report_id,
+				     st->poll.index, sizeof(value), &value);
 	if (ret < 0 || value < 0) {
 		*val1 = *val2 = 0;
 		return -EINVAL;
@@ -212,9 +212,8 @@ int hid_sensor_write_samp_freq_value(struct hid_sensor_common *st,
 		else
 			value = 0;
 	}
-	ret = sensor_hub_set_feature(st->hsdev,
-		st->poll.report_id,
-		st->poll.index, value);
+	ret = sensor_hub_set_feature(st->hsdev, st->poll.report_id,
+				     st->poll.index, sizeof(value), &value);
 	if (ret < 0 || value < 0)
 		ret = -EINVAL;

@@ -229,8 +228,9 @@ int hid_sensor_read_raw_hyst_value(struct hid_sensor_common *st,
 	int ret;

 	ret = sensor_hub_get_feature(st->hsdev,
-		st->sensitivity.report_id,
-		st->sensitivity.index, &value);
+				     st->sensitivity.report_id,
+				     st->sensitivity.index, sizeof(value),
+				     &value);
 	if (ret < 0 || value < 0) {
 		*val1 = *val2 = 0;
 		return -EINVAL;
@@ -253,9 +253,9 @@ int hid_sensor_write_raw_hyst_value(struct hid_sensor_common *st,
 	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, value);
+	ret = sensor_hub_set_feature(st->hsdev, st->sensitivity.report_id,
+				     st->sensitivity.index, sizeof(value),
+				     &value);
 	if (ret < 0 || value < 0)
 		ret = -EINVAL;

@@ -68,20 +68,21 @@ static int _hid_sensor_power_state(struct hid_sensor_common *st, bool state)
 	if (state_val >= 0) {
 		state_val += st->power_state.logical_minimum;
 		sensor_hub_set_feature(st->hsdev, st->power_state.report_id,
-					st->power_state.index,
-					(s32)state_val);
+				       st->power_state.index, sizeof(state_val),
+				       &state_val);
 	}

 	if (report_val >= 0) {
 		report_val += st->report_state.logical_minimum;
 		sensor_hub_set_feature(st->hsdev, st->report_state.report_id,
-					st->report_state.index,
-					(s32)report_val);
+				       st->report_state.index,
+				       sizeof(report_val),
+				       &report_val);
 	}

 	sensor_hub_get_feature(st->hsdev, st->power_state.report_id,
-					st->power_state.index,
-					&state_val);
+			       st->power_state.index,
+			       sizeof(state_val), &state_val);
 	if (state && poll_value)
 		msleep_interruptible(poll_value * 2);

@@ -123,7 +123,8 @@ static int gyro_3d_read_raw(struct iio_dev *indio_dev,
 			*val = sensor_hub_input_attr_get_raw_value(
 					gyro_state->common_attributes.hsdev,
 					HID_USAGE_SENSOR_GYRO_3D, address,
-					report_id);
+					report_id,
+					SENSOR_HUB_SYNC);
 		else {
 			*val = 0;
 			hid_sensor_power_state(&gyro_state->common_attributes,
@@ -101,7 +101,8 @@ static int als_read_raw(struct iio_dev *indio_dev,
 			*val = sensor_hub_input_attr_get_raw_value(
 					als_state->common_attributes.hsdev,
 					HID_USAGE_SENSOR_ALS, address,
-					report_id);
+					report_id,
+					SENSOR_HUB_SYNC);
 			hid_sensor_power_state(&als_state->common_attributes,
 						false);
 		} else {
@@ -96,7 +96,8 @@ static int prox_read_raw(struct iio_dev *indio_dev,
 			*val = sensor_hub_input_attr_get_raw_value(
 				prox_state->common_attributes.hsdev,
 				HID_USAGE_SENSOR_PROX, address,
-				report_id);
+				report_id,
+				SENSOR_HUB_SYNC);
 			hid_sensor_power_state(&prox_state->common_attributes,
 						false);
 		} else {
@@ -170,7 +170,8 @@ static int magn_3d_read_raw(struct iio_dev *indio_dev,
 			*val = sensor_hub_input_attr_get_raw_value(
 				magn_state->common_attributes.hsdev,
 				HID_USAGE_SENSOR_COMPASS_3D, address,
-				report_id);
+				report_id,
+				SENSOR_HUB_SYNC);
 		else {
 			*val = 0;
 			hid_sensor_power_state(&magn_state->common_attributes,
@@ -124,7 +124,8 @@ static int incl_3d_read_raw(struct iio_dev *indio_dev,
 			*val = sensor_hub_input_attr_get_raw_value(
 				incl_state->common_attributes.hsdev,
 				HID_USAGE_SENSOR_INCLINOMETER_3D, address,
-				report_id);
+				report_id,
+				SENSOR_HUB_SYNC);
 		else {
 			hid_sensor_power_state(&incl_state->common_attributes,
 						false);
@@ -100,7 +100,8 @@ static int press_read_raw(struct iio_dev *indio_dev,
 			*val = sensor_hub_input_attr_get_raw_value(
 				press_state->common_attributes.hsdev,
 				HID_USAGE_SENSOR_PRESSURE, address,
-				report_id);
+				report_id,
+				SENSOR_HUB_SYNC);
 			hid_sensor_power_state(&press_state->common_attributes,
 						false);
 		} else {
@@ -213,7 +213,7 @@ static int hid_rtc_read_time(struct device *dev, struct rtc_time *tm)
 	/* get a report with all values through requesting one value */
 	sensor_hub_input_attr_get_raw_value(time_state->common_attributes.hsdev,
 			HID_USAGE_SENSOR_TIME, hid_time_addresses[0],
-			time_state->info[0].report_id);
+			time_state->info[0].report_id, SENSOR_HUB_SYNC);
 	/* wait for all values (event) */
 	ret = wait_for_completion_killable_timeout(
 			&time_state->comp_last_time, HZ*6);
@@ -48,20 +48,44 @@ struct hid_sensor_hub_attribute_info {
 	s32 logical_maximum;
 };

+/**
+ * struct sensor_hub_pending - Synchronous read pending information
+ * @status:		Pending status true/false.
+ * @ready:		Completion synchronization data.
+ * @usage_id:		Usage id for physical device, E.g. Gyro usage id.
+ * @attr_usage_id:	Usage Id of a field, E.g. X-AXIS for a gyro.
+ * @raw_size:		Response size for a read request.
+ * @raw_data:		Place holder for received response.
+ */
+struct sensor_hub_pending {
+	bool status;
+	struct completion ready;
+	u32 usage_id;
+	u32 attr_usage_id;
+	int raw_size;
+	u8  *raw_data;
+};
+
 /**
 * struct hid_sensor_hub_device - Stores the hub instance data
 * @hdev:		Stores the hid instance.
 * @vendor_id:		Vendor id of hub device.
 * @product_id:		Product id of hub device.
+ * @usage:		Usage id for this hub device instance.
 * @start_collection_index: Starting index for a phy type collection
 * @end_collection_index: Last index for a phy type collection
+ * @mutex:		synchronizing mutex.
+ * @pending:		Holds information of pending sync read request.
 */
 struct hid_sensor_hub_device {
 	struct hid_device *hdev;
 	u32 vendor_id;
 	u32 product_id;
+	u32 usage;
 	int start_collection_index;
 	int end_collection_index;
+	struct mutex mutex;
+	struct sensor_hub_pending pending;
 };

 /**
@@ -152,40 +176,51 @@ int sensor_hub_input_get_attribute_info(struct hid_sensor_hub_device *hsdev,
 * @usage_id:	Attribute usage id of parent physical device as per spec
 * @attr_usage_id:	Attribute usage id as per spec
 * @report_id:	Report id to look for
+* @flag:      Synchronous or asynchronous read
 *
-* Issues a synchronous read request for an input attribute. Returns
-* data upto 32 bits. Since client can get events, so this call should
-* not be used for data paths, this will impact performance.
+* Issues a synchronous or asynchronous read request for an input attribute.
+* Returns data upto 32 bits.
 */

+enum sensor_hub_read_flags {
+	SENSOR_HUB_SYNC,
+	SENSOR_HUB_ASYNC,
+};
+
 int sensor_hub_input_attr_get_raw_value(struct hid_sensor_hub_device *hsdev,
-			u32 usage_id,
-			u32 attr_usage_id, u32 report_id);
+ 					u32 usage_id,
+ 					u32 attr_usage_id, u32 report_id,
+ 					enum sensor_hub_read_flags flag
+);
+
 /**
 * sensor_hub_set_feature() - Feature set request
 * @hsdev:	Hub device instance.
 * @report_id:	Report id to look for
 * @field_index:	Field index inside a report
-* @value:	Value to set
+* @buffer_size: size of the buffer
+* @buffer:	buffer to use in the feature set
 *
 * Used to set a field in feature report. For example this can set polling
 * interval, sensitivity, activate/deactivate state.
 */
 int sensor_hub_set_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
-			u32 field_index, s32 value);
+			   u32 field_index, int buffer_size, void *buffer);

 /**
 * sensor_hub_get_feature() - Feature get request
 * @hsdev:	Hub device instance.
 * @report_id:	Report id to look for
 * @field_index:	Field index inside a report
-* @value:	Place holder for return value
+* @buffer_size:	size of the buffer
+* @buffer:	buffer to copy output
 *
 * Used to get a field in feature report. For example this can get polling
-* interval, sensitivity, activate/deactivate state.
+* interval, sensitivity, activate/deactivate state. On success it returns
+* number of bytes copied to buffer. On failure, it returns value < 0.
 */
 int sensor_hub_get_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
-			u32 field_index, s32 *value);
+			   u32 field_index, int buffer_size, void *buffer);

 /* hid-sensor-attributes */

@@ -21,6 +21,8 @@

 #define HID_MAX_PHY_DEVICES					0xFF

+#define HID_USAGE_SENSOR_COLLECTION				0x200001
+
 /* Accel 3D (200073) */
 #define HID_USAGE_SENSOR_ACCEL_3D				0x200073
 #define HID_USAGE_SENSOR_DATA_ACCELERATION			0x200452