drivers/iio/orientation/hid-sensor-rotation.c - arm/linux - Git at Google

 /*
  * HID Sensors Driver
  * Copyright (c) 2014, 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.
  */

 #include <linux/device.h>
 #include <linux/platform_device.h>
 #include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/slab.h>
 #include <linux/hid-sensor-hub.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/iio/buffer.h>
 #include <linux/iio/trigger_consumer.h>
 #include <linux/iio/triggered_buffer.h>
 #include "../common/hid-sensors/hid-sensor-trigger.h"

 struct dev_rot_state {
 	struct hid_sensor_hub_callbacks callbacks;
 	struct hid_sensor_common common_attributes;
 	struct hid_sensor_hub_attribute_info quaternion;
 	u32 sampled_vals[4];
 	int scale_pre_decml;
 	int scale_post_decml;
 	int scale_precision;
 	int value_offset;
 };

 /* Channel definitions */
 static const struct iio_chan_spec dev_rot_channels[] = {
 	{
 		.type = IIO_ROT,
 		.modified = 1,
 		.channel2 = IIO_MOD_QUATERNION,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) |
 					BIT(IIO_CHAN_INFO_OFFSET) |
 					BIT(IIO_CHAN_INFO_SCALE) |
 					BIT(IIO_CHAN_INFO_HYSTERESIS)
 	}
 };

 /* Adjust channel real bits based on report descriptor */
 static void dev_rot_adjust_channel_bit_mask(struct iio_chan_spec *chan,
 						int size)
 {
 	chan->scan_type.sign = 's';
 	/* Real storage bits will change based on the report desc. */
 	chan->scan_type.realbits = size * 8;
 	/* Maximum size of a sample to capture is u32 */
 	chan->scan_type.storagebits = sizeof(u32) * 8;
 	chan->scan_type.repeat = 4;
 }

 /* Channel read_raw handler */
 static int dev_rot_read_raw(struct iio_dev *indio_dev,
 				struct iio_chan_spec const *chan,
 				int size, int *vals, int *val_len,
 				long mask)
 {
 	struct dev_rot_state *rot_state = iio_priv(indio_dev);
 	int ret_type;
 	int i;

 	vals[0] = 0;
 	vals[1] = 0;

 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 		if (size >= 4) {
 			for (i = 0; i < 4; ++i)
 				vals[i] = rot_state->sampled_vals[i];
 			ret_type = IIO_VAL_INT_MULTIPLE;
 			*val_len =  4;
 		} else
 			ret_type = -EINVAL;
 		break;
 	case IIO_CHAN_INFO_SCALE:
 		vals[0] = rot_state->scale_pre_decml;
 		vals[1] = rot_state->scale_post_decml;
 		return rot_state->scale_precision;

 	case IIO_CHAN_INFO_OFFSET:
 		*vals = rot_state->value_offset;
 		return IIO_VAL_INT;

 	case IIO_CHAN_INFO_SAMP_FREQ:
 		ret_type = hid_sensor_read_samp_freq_value(
 			&rot_state->common_attributes, &vals[0], &vals[1]);
 		break;
 	case IIO_CHAN_INFO_HYSTERESIS:
 		ret_type = hid_sensor_read_raw_hyst_value(
 			&rot_state->common_attributes, &vals[0], &vals[1]);
 		break;
 	default:
 		ret_type = -EINVAL;
 		break;
 	}

 	return ret_type;
 }

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

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

 	return ret;
 }

 static const struct iio_info dev_rot_info = {
 	.driver_module = THIS_MODULE,
 	.read_raw_multi = &dev_rot_read_raw,
 	.write_raw = &dev_rot_write_raw,
 };

 /* Function to push data to buffer */
 static void hid_sensor_push_data(struct iio_dev *indio_dev, u8 *data, int len)
 {
 	dev_dbg(&indio_dev->dev, "hid_sensor_push_data >>\n");
 	iio_push_to_buffers(indio_dev, (u8 *)data);
 	dev_dbg(&indio_dev->dev, "hid_sensor_push_data <<\n");

 }

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

 	dev_dbg(&indio_dev->dev, "dev_rot_proc_event\n");
 	if (atomic_read(&rot_state->common_attributes.data_ready))
 		hid_sensor_push_data(indio_dev,
 				(u8 *)rot_state->sampled_vals,
 				sizeof(rot_state->sampled_vals));

 	return 0;
 }

 /* Capture samples in local storage */
 static int dev_rot_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 dev_rot_state *rot_state = iio_priv(indio_dev);

 	if (usage_id == HID_USAGE_SENSOR_ORIENT_QUATERNION) {
 		memcpy(rot_state->sampled_vals, raw_data,
 					sizeof(rot_state->sampled_vals));
 		dev_dbg(&indio_dev->dev, "Recd Quat len:%zu::%zu\n", raw_len,
 					sizeof(rot_state->sampled_vals));
 	}

 	return 0;
 }

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

 	ret = sensor_hub_input_get_attribute_info(hsdev,
 				HID_INPUT_REPORT,
 				usage_id,
 				HID_USAGE_SENSOR_ORIENT_QUATERNION,
 				&st->quaternion);
 	if (ret)
 		return ret;

 	dev_rot_adjust_channel_bit_mask(&channels[0],
 		st->quaternion.size / 4);

 	dev_dbg(&pdev->dev, "dev_rot %x:%x\n", st->quaternion.index,
 		st->quaternion.report_id);

 	dev_dbg(&pdev->dev, "dev_rot: attrib size %d\n",
 				st->quaternion.size);

 	st->scale_precision = hid_sensor_format_scale(
 				hsdev->usage,
 				&st->quaternion,
 				&st->scale_pre_decml, &st->scale_post_decml);

 	/* Set Sensitivity field ids, when there is no individual modifier */
 	if (st->common_attributes.sensitivity.index < 0) {
 		sensor_hub_input_get_attribute_info(hsdev,
 			HID_FEATURE_REPORT, usage_id,
 			HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
 			HID_USAGE_SENSOR_DATA_ORIENTATION,
 			&st->common_attributes.sensitivity);
 		dev_dbg(&pdev->dev, "Sensitivity index:report %d:%d\n",
 			st->common_attributes.sensitivity.index,
 			st->common_attributes.sensitivity.report_id);
 	}

 	return 0;
 }

 /* Function to initialize the processing for usage id */
 static int hid_dev_rot_probe(struct platform_device *pdev)
 {
 	int ret;
 	char *name;
 	struct iio_dev *indio_dev;
 	struct dev_rot_state *rot_state;
 	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;

 	indio_dev = devm_iio_device_alloc(&pdev->dev,
 					  sizeof(struct dev_rot_state));
 	if (indio_dev == NULL)
 		return -ENOMEM;

 	platform_set_drvdata(pdev, indio_dev);

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

 	switch (hsdev->usage) {
 	case HID_USAGE_SENSOR_DEVICE_ORIENTATION:
 		name = "dev_rotation";
 		break;
 	case HID_USAGE_SENSOR_RELATIVE_ORIENTATION:
 		name = "relative_orientation";
 		break;
 	case HID_USAGE_SENSOR_GEOMAGNETIC_ORIENTATION:
 		name = "geomagnetic_orientation";
 		break;
 	default:
 		return -EINVAL;
 	}

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

 	indio_dev->channels = devm_kmemdup(&pdev->dev, dev_rot_channels,
 					   sizeof(dev_rot_channels),
 					   GFP_KERNEL);
 	if (!indio_dev->channels) {
 		dev_err(&pdev->dev, "failed to duplicate channels\n");
 		return -ENOMEM;
 	}

 	ret = dev_rot_parse_report(pdev, hsdev,
 				   (struct iio_chan_spec *)indio_dev->channels,
 					hsdev->usage, rot_state);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to setup attributes\n");
 		return ret;
 	}

 	indio_dev->num_channels = ARRAY_SIZE(dev_rot_channels);
 	indio_dev->dev.parent = &pdev->dev;
 	indio_dev->info = &dev_rot_info;
 	indio_dev->name = name;
 	indio_dev->modes = INDIO_DIRECT_MODE;

 	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
 		NULL, NULL);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to initialize trigger buffer\n");
 		return ret;
 	}
 	atomic_set(&rot_state->common_attributes.data_ready, 0);
 	ret = hid_sensor_setup_trigger(indio_dev, name,
 					&rot_state->common_attributes);
 	if (ret) {
 		dev_err(&pdev->dev, "trigger setup failed\n");
 		goto error_unreg_buffer_funcs;
 	}

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

 	rot_state->callbacks.send_event = dev_rot_proc_event;
 	rot_state->callbacks.capture_sample = dev_rot_capture_sample;
 	rot_state->callbacks.pdev = pdev;
 	ret = sensor_hub_register_callback(hsdev, hsdev->usage,
 					&rot_state->callbacks);
 	if (ret) {
 		dev_err(&pdev->dev, "callback reg failed\n");
 		goto error_iio_unreg;
 	}

 	return 0;

 error_iio_unreg:
 	iio_device_unregister(indio_dev);
 error_remove_trigger:
 	hid_sensor_remove_trigger(&rot_state->common_attributes);
 error_unreg_buffer_funcs:
 	iio_triggered_buffer_cleanup(indio_dev);
 	return ret;
 }

 /* Function to deinitialize the processing for usage id */
 static int hid_dev_rot_remove(struct platform_device *pdev)
 {
 	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 	struct dev_rot_state *rot_state = iio_priv(indio_dev);

 	sensor_hub_remove_callback(hsdev, hsdev->usage);
 	iio_device_unregister(indio_dev);
 	hid_sensor_remove_trigger(&rot_state->common_attributes);
 	iio_triggered_buffer_cleanup(indio_dev);

 	return 0;
 }

 static const struct platform_device_id hid_dev_rot_ids[] = {
 	{
 		/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
 		.name = "HID-SENSOR-20008a",
 	},
 	{
 		/* Relative orientation(AG) sensor */
 		.name = "HID-SENSOR-20008e",
 	},
 	{
 		/* Geomagnetic orientation(AM) sensor */
 		.name = "HID-SENSOR-2000c1",
 	},
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(platform, hid_dev_rot_ids);

 static struct platform_driver hid_dev_rot_platform_driver = {
 	.id_table = hid_dev_rot_ids,
 	.driver = {
 		.name	= KBUILD_MODNAME,
 		.pm     = &hid_sensor_pm_ops,
 	},
 	.probe		= hid_dev_rot_probe,
 	.remove		= hid_dev_rot_remove,
 };
 module_platform_driver(hid_dev_rot_platform_driver);

 MODULE_DESCRIPTION("HID Sensor Device Rotation");
 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
 MODULE_LICENSE("GPL");
	/*
	* HID Sensors Driver
	* Copyright (c) 2014, 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.
	*/

	#include <linux/device.h>
	#include <linux/platform_device.h>
	#include <linux/module.h>
	#include <linux/interrupt.h>
	#include <linux/irq.h>
	#include <linux/slab.h>
	#include <linux/hid-sensor-hub.h>
	#include <linux/iio/iio.h>
	#include <linux/iio/sysfs.h>
	#include <linux/iio/buffer.h>
	#include <linux/iio/trigger_consumer.h>
	#include <linux/iio/triggered_buffer.h>
	#include "../common/hid-sensors/hid-sensor-trigger.h"

	struct dev_rot_state {
	struct hid_sensor_hub_callbacks callbacks;
	struct hid_sensor_common common_attributes;
	struct hid_sensor_hub_attribute_info quaternion;
	u32 sampled_vals[4];
	int scale_pre_decml;
	int scale_post_decml;
	int scale_precision;
	int value_offset;
	};

	/* Channel definitions */
	static const struct iio_chan_spec dev_rot_channels[] = {
	{
	.type = IIO_ROT,
	.modified = 1,
	.channel2 = IIO_MOD_QUATERNION,
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) \|
	BIT(IIO_CHAN_INFO_OFFSET) \|
	BIT(IIO_CHAN_INFO_SCALE) \|
	BIT(IIO_CHAN_INFO_HYSTERESIS)
	}
	};

	/* Adjust channel real bits based on report descriptor */
	static void dev_rot_adjust_channel_bit_mask(struct iio_chan_spec *chan,
	int size)
	{
	chan->scan_type.sign = 's';
	/* Real storage bits will change based on the report desc. */
	chan->scan_type.realbits = size * 8;
	/* Maximum size of a sample to capture is u32 */
	chan->scan_type.storagebits = sizeof(u32) * 8;
	chan->scan_type.repeat = 4;
	}

	/* Channel read_raw handler */
	static int dev_rot_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int size, int vals, int val_len,
	long mask)
	{
	struct dev_rot_state *rot_state = iio_priv(indio_dev);
	int ret_type;
	int i;

	vals[0] = 0;
	vals[1] = 0;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
	if (size >= 4) {
	for (i = 0; i < 4; ++i)
	vals[i] = rot_state->sampled_vals[i];
	ret_type = IIO_VAL_INT_MULTIPLE;
	*val_len = 4;
	} else
	ret_type = -EINVAL;
	break;
	case IIO_CHAN_INFO_SCALE:
	vals[0] = rot_state->scale_pre_decml;
	vals[1] = rot_state->scale_post_decml;
	return rot_state->scale_precision;

	case IIO_CHAN_INFO_OFFSET:
	*vals = rot_state->value_offset;
	return IIO_VAL_INT;

	case IIO_CHAN_INFO_SAMP_FREQ:
	ret_type = hid_sensor_read_samp_freq_value(
	&rot_state->common_attributes, &vals[0], &vals[1]);
	break;
	case IIO_CHAN_INFO_HYSTERESIS:
	ret_type = hid_sensor_read_raw_hyst_value(
	&rot_state->common_attributes, &vals[0], &vals[1]);
	break;
	default:
	ret_type = -EINVAL;
	break;
	}

	return ret_type;
	}

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

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

	return ret;
	}

	static const struct iio_info dev_rot_info = {
	.driver_module = THIS_MODULE,
	.read_raw_multi = &dev_rot_read_raw,
	.write_raw = &dev_rot_write_raw,
	};

	/* Function to push data to buffer */
	static void hid_sensor_push_data(struct iio_dev indio_dev, u8 data, int len)
	{
	dev_dbg(&indio_dev->dev, "hid_sensor_push_data >>\n");
	iio_push_to_buffers(indio_dev, (u8 *)data);
	dev_dbg(&indio_dev->dev, "hid_sensor_push_data <<\n");

	}

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

	dev_dbg(&indio_dev->dev, "dev_rot_proc_event\n");
	if (atomic_read(&rot_state->common_attributes.data_ready))
	hid_sensor_push_data(indio_dev,
	(u8 *)rot_state->sampled_vals,
	sizeof(rot_state->sampled_vals));

	return 0;
	}

	/* Capture samples in local storage */
	static int dev_rot_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 dev_rot_state *rot_state = iio_priv(indio_dev);

	if (usage_id == HID_USAGE_SENSOR_ORIENT_QUATERNION) {
	memcpy(rot_state->sampled_vals, raw_data,
	sizeof(rot_state->sampled_vals));
	dev_dbg(&indio_dev->dev, "Recd Quat len:%zu::%zu\n", raw_len,
	sizeof(rot_state->sampled_vals));
	}

	return 0;
	}

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

	ret = sensor_hub_input_get_attribute_info(hsdev,
	HID_INPUT_REPORT,
	usage_id,
	HID_USAGE_SENSOR_ORIENT_QUATERNION,
	&st->quaternion);
	if (ret)
	return ret;

	dev_rot_adjust_channel_bit_mask(&channels[0],
	st->quaternion.size / 4);

	dev_dbg(&pdev->dev, "dev_rot %x:%x\n", st->quaternion.index,
	st->quaternion.report_id);

	dev_dbg(&pdev->dev, "dev_rot: attrib size %d\n",
	st->quaternion.size);

	st->scale_precision = hid_sensor_format_scale(
	hsdev->usage,
	&st->quaternion,
	&st->scale_pre_decml, &st->scale_post_decml);

	/* Set Sensitivity field ids, when there is no individual modifier */
	if (st->common_attributes.sensitivity.index < 0) {
	sensor_hub_input_get_attribute_info(hsdev,
	HID_FEATURE_REPORT, usage_id,
	HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS \|
	HID_USAGE_SENSOR_DATA_ORIENTATION,
	&st->common_attributes.sensitivity);
	dev_dbg(&pdev->dev, "Sensitivity index:report %d:%d\n",
	st->common_attributes.sensitivity.index,
	st->common_attributes.sensitivity.report_id);
	}

	return 0;
	}

	/* Function to initialize the processing for usage id */
	static int hid_dev_rot_probe(struct platform_device *pdev)
	{
	int ret;
	char *name;
	struct iio_dev *indio_dev;
	struct dev_rot_state *rot_state;
	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;

	indio_dev = devm_iio_device_alloc(&pdev->dev,
	sizeof(struct dev_rot_state));
	if (indio_dev == NULL)
	return -ENOMEM;

	platform_set_drvdata(pdev, indio_dev);

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

	switch (hsdev->usage) {
	case HID_USAGE_SENSOR_DEVICE_ORIENTATION:
	name = "dev_rotation";
	break;
	case HID_USAGE_SENSOR_RELATIVE_ORIENTATION:
	name = "relative_orientation";
	break;
	case HID_USAGE_SENSOR_GEOMAGNETIC_ORIENTATION:
	name = "geomagnetic_orientation";
	break;
	default:
	return -EINVAL;
	}

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

	indio_dev->channels = devm_kmemdup(&pdev->dev, dev_rot_channels,
	sizeof(dev_rot_channels),
	GFP_KERNEL);
	if (!indio_dev->channels) {
	dev_err(&pdev->dev, "failed to duplicate channels\n");
	return -ENOMEM;
	}

	ret = dev_rot_parse_report(pdev, hsdev,
	(struct iio_chan_spec *)indio_dev->channels,
	hsdev->usage, rot_state);
	if (ret) {
	dev_err(&pdev->dev, "failed to setup attributes\n");
	return ret;
	}

	indio_dev->num_channels = ARRAY_SIZE(dev_rot_channels);
	indio_dev->dev.parent = &pdev->dev;
	indio_dev->info = &dev_rot_info;
	indio_dev->name = name;
	indio_dev->modes = INDIO_DIRECT_MODE;

	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
	NULL, NULL);
	if (ret) {
	dev_err(&pdev->dev, "failed to initialize trigger buffer\n");
	return ret;
	}
	atomic_set(&rot_state->common_attributes.data_ready, 0);
	ret = hid_sensor_setup_trigger(indio_dev, name,
	&rot_state->common_attributes);
	if (ret) {
	dev_err(&pdev->dev, "trigger setup failed\n");
	goto error_unreg_buffer_funcs;
	}

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

	rot_state->callbacks.send_event = dev_rot_proc_event;
	rot_state->callbacks.capture_sample = dev_rot_capture_sample;
	rot_state->callbacks.pdev = pdev;
	ret = sensor_hub_register_callback(hsdev, hsdev->usage,
	&rot_state->callbacks);
	if (ret) {
	dev_err(&pdev->dev, "callback reg failed\n");
	goto error_iio_unreg;
	}

	return 0;

	error_iio_unreg:
	iio_device_unregister(indio_dev);
	error_remove_trigger:
	hid_sensor_remove_trigger(&rot_state->common_attributes);
	error_unreg_buffer_funcs:
	iio_triggered_buffer_cleanup(indio_dev);
	return ret;
	}

	/* Function to deinitialize the processing for usage id */
	static int hid_dev_rot_remove(struct platform_device *pdev)
	{
	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
	struct dev_rot_state *rot_state = iio_priv(indio_dev);

	sensor_hub_remove_callback(hsdev, hsdev->usage);
	iio_device_unregister(indio_dev);
	hid_sensor_remove_trigger(&rot_state->common_attributes);
	iio_triggered_buffer_cleanup(indio_dev);

	return 0;
	}

	static const struct platform_device_id hid_dev_rot_ids[] = {
	{
	/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
	.name = "HID-SENSOR-20008a",
	},
	{
	/* Relative orientation(AG) sensor */
	.name = "HID-SENSOR-20008e",
	},
	{
	/* Geomagnetic orientation(AM) sensor */
	.name = "HID-SENSOR-2000c1",
	},
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(platform, hid_dev_rot_ids);

	static struct platform_driver hid_dev_rot_platform_driver = {
	.id_table = hid_dev_rot_ids,
	.driver = {
	.name = KBUILD_MODNAME,
	.pm = &hid_sensor_pm_ops,
	},
	.probe = hid_dev_rot_probe,
	.remove = hid_dev_rot_remove,
	};
	module_platform_driver(hid_dev_rot_platform_driver);

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