drivers/iio/light/hid-sensor-als.c - arm/linux - Git at Google

 /*
  * 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/platform_device.h>
 #include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/slab.h>
 #include <linux/delay.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"

 enum {
 	CHANNEL_SCAN_INDEX_INTENSITY = 0,
 	CHANNEL_SCAN_INDEX_ILLUM = 1,
 	CHANNEL_SCAN_INDEX_MAX
 };

 struct als_state {
 	struct hid_sensor_hub_callbacks callbacks;
 	struct hid_sensor_common common_attributes;
 	struct hid_sensor_hub_attribute_info als_illum;
 	u32 illum[CHANNEL_SCAN_INDEX_MAX];
 	int scale_pre_decml;
 	int scale_post_decml;
 	int scale_precision;
 	int value_offset;
 };

 /* Channel definitions */
 static const struct iio_chan_spec als_channels[] = {
 	{
 		.type = IIO_INTENSITY,
 		.modified = 1,
 		.channel2 = IIO_MOD_LIGHT_BOTH,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
 		BIT(IIO_CHAN_INFO_SCALE) |
 		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
 		BIT(IIO_CHAN_INFO_HYSTERESIS),
 		.scan_index = CHANNEL_SCAN_INDEX_INTENSITY,
 	},
 	{
 		.type = IIO_LIGHT,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
 		BIT(IIO_CHAN_INFO_SCALE) |
 		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
 		BIT(IIO_CHAN_INFO_HYSTERESIS),
 		.scan_index = CHANNEL_SCAN_INDEX_ILLUM,
 	}
 };

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

 /* Channel read_raw handler */
 static int als_read_raw(struct iio_dev *indio_dev,
 			      struct iio_chan_spec const *chan,
 			      int *val, int *val2,
 			      long mask)
 {
 	struct als_state *als_state = iio_priv(indio_dev);
 	int report_id = -1;
 	u32 address;
 	int ret_type;

 	*val = 0;
 	*val2 = 0;
 	switch (mask) {
 	case 0:
 		switch (chan->scan_index) {
 		case  CHANNEL_SCAN_INDEX_INTENSITY:
 		case  CHANNEL_SCAN_INDEX_ILLUM:
 			report_id = als_state->als_illum.report_id;
 			address =
 			HID_USAGE_SENSOR_LIGHT_ILLUM;
 			break;
 		default:
 			report_id = -1;
 			break;
 		}
 		if (report_id >= 0) {
 			hid_sensor_power_state(&als_state->common_attributes,
 						true);
 			*val = sensor_hub_input_attr_get_raw_value(
 					als_state->common_attributes.hsdev,
 					HID_USAGE_SENSOR_ALS, address,
 					report_id,
 					SENSOR_HUB_SYNC);
 			hid_sensor_power_state(&als_state->common_attributes,
 						false);
 		} else {
 			*val = 0;
 			return -EINVAL;
 		}
 		ret_type = IIO_VAL_INT;
 		break;
 	case IIO_CHAN_INFO_SCALE:
 		*val = als_state->scale_pre_decml;
 		*val2 = als_state->scale_post_decml;
 		ret_type = als_state->scale_precision;
 		break;
 	case IIO_CHAN_INFO_OFFSET:
 		*val = als_state->value_offset;
 		ret_type = IIO_VAL_INT;
 		break;
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		ret_type = hid_sensor_read_samp_freq_value(
 				&als_state->common_attributes, val, val2);
 		break;
 	case IIO_CHAN_INFO_HYSTERESIS:
 		ret_type = hid_sensor_read_raw_hyst_value(
 				&als_state->common_attributes, val, val2);
 		break;
 	default:
 		ret_type = -EINVAL;
 		break;
 	}

 	return ret_type;
 }

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

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

 	return ret;
 }

 static const struct iio_info als_info = {
 	.driver_module = THIS_MODULE,
 	.read_raw = &als_read_raw,
 	.write_raw = &als_write_raw,
 };

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

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

 	dev_dbg(&indio_dev->dev, "als_proc_event\n");
 	if (atomic_read(&als_state->common_attributes.data_ready))
 		hid_sensor_push_data(indio_dev,
 				&als_state->illum,
 				sizeof(als_state->illum));

 	return 0;
 }

 /* Capture samples in local storage */
 static int als_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 als_state *als_state = iio_priv(indio_dev);
 	int ret = -EINVAL;
 	u32 sample_data = *(u32 *)raw_data;

 	switch (usage_id) {
 	case HID_USAGE_SENSOR_LIGHT_ILLUM:
 		als_state->illum[CHANNEL_SCAN_INDEX_INTENSITY] = sample_data;
 		als_state->illum[CHANNEL_SCAN_INDEX_ILLUM] = sample_data;
 		ret = 0;
 		break;
 	default:
 		break;
 	}

 	return ret;
 }

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

 	ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
 			usage_id,
 			HID_USAGE_SENSOR_LIGHT_ILLUM,
 			&st->als_illum);
 	if (ret < 0)
 		return ret;
 	als_adjust_channel_bit_mask(channels, CHANNEL_SCAN_INDEX_INTENSITY,
 				    st->als_illum.size);
 	als_adjust_channel_bit_mask(channels, CHANNEL_SCAN_INDEX_ILLUM,
 					st->als_illum.size);

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

 	st->scale_precision = hid_sensor_format_scale(
 				HID_USAGE_SENSOR_ALS,
 				&st->als_illum,
 				&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_LIGHT,
 			&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 ret;
 }

 /* Function to initialize the processing for usage id */
 static int hid_als_probe(struct platform_device *pdev)
 {
 	int ret = 0;
 	static const char *name = "als";
 	struct iio_dev *indio_dev;
 	struct als_state *als_state;
 	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;

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

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

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

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

 	ret = als_parse_report(pdev, hsdev,
 			       (struct iio_chan_spec *)indio_dev->channels,
 			       HID_USAGE_SENSOR_ALS, als_state);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to setup attributes\n");
 		goto error_free_dev_mem;
 	}

 	indio_dev->num_channels =
 				ARRAY_SIZE(als_channels);
 	indio_dev->dev.parent = &pdev->dev;
 	indio_dev->info = &als_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");
 		goto error_free_dev_mem;
 	}
 	atomic_set(&als_state->common_attributes.data_ready, 0);
 	ret = hid_sensor_setup_trigger(indio_dev, name,
 				&als_state->common_attributes);
 	if (ret < 0) {
 		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;
 	}

 	als_state->callbacks.send_event = als_proc_event;
 	als_state->callbacks.capture_sample = als_capture_sample;
 	als_state->callbacks.pdev = pdev;
 	ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_ALS,
 					&als_state->callbacks);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "callback reg failed\n");
 		goto error_iio_unreg;
 	}

 	return ret;

 error_iio_unreg:
 	iio_device_unregister(indio_dev);
 error_remove_trigger:
 	hid_sensor_remove_trigger(&als_state->common_attributes);
 error_unreg_buffer_funcs:
 	iio_triggered_buffer_cleanup(indio_dev);
 error_free_dev_mem:
 	kfree(indio_dev->channels);
 	return ret;
 }

 /* Function to deinitialize the processing for usage id */
 static int hid_als_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 als_state *als_state = iio_priv(indio_dev);

 	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_ALS);
 	iio_device_unregister(indio_dev);
 	hid_sensor_remove_trigger(&als_state->common_attributes);
 	iio_triggered_buffer_cleanup(indio_dev);
 	kfree(indio_dev->channels);

 	return 0;
 }

 static const struct platform_device_id hid_als_ids[] = {
 	{
 		/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
 		.name = "HID-SENSOR-200041",
 	},
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(platform, hid_als_ids);

 static struct platform_driver hid_als_platform_driver = {
 	.id_table = hid_als_ids,
 	.driver = {
 		.name	= KBUILD_MODNAME,
 		.pm	= &hid_sensor_pm_ops,
 	},
 	.probe		= hid_als_probe,
 	.remove		= hid_als_remove,
 };
 module_platform_driver(hid_als_platform_driver);

 MODULE_DESCRIPTION("HID Sensor ALS");
 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@intel.com>");
 MODULE_LICENSE("GPL");
	/*
	* 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/platform_device.h>
	#include <linux/module.h>
	#include <linux/interrupt.h>
	#include <linux/irq.h>
	#include <linux/slab.h>
	#include <linux/delay.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"

	enum {
	CHANNEL_SCAN_INDEX_INTENSITY = 0,
	CHANNEL_SCAN_INDEX_ILLUM = 1,
	CHANNEL_SCAN_INDEX_MAX
	};

	struct als_state {
	struct hid_sensor_hub_callbacks callbacks;
	struct hid_sensor_common common_attributes;
	struct hid_sensor_hub_attribute_info als_illum;
	u32 illum[CHANNEL_SCAN_INDEX_MAX];
	int scale_pre_decml;
	int scale_post_decml;
	int scale_precision;
	int value_offset;
	};

	/* Channel definitions */
	static const struct iio_chan_spec als_channels[] = {
	{
	.type = IIO_INTENSITY,
	.modified = 1,
	.channel2 = IIO_MOD_LIGHT_BOTH,
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) \|
	BIT(IIO_CHAN_INFO_SCALE) \|
	BIT(IIO_CHAN_INFO_SAMP_FREQ) \|
	BIT(IIO_CHAN_INFO_HYSTERESIS),
	.scan_index = CHANNEL_SCAN_INDEX_INTENSITY,
	},
	{
	.type = IIO_LIGHT,
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) \|
	BIT(IIO_CHAN_INFO_SCALE) \|
	BIT(IIO_CHAN_INFO_SAMP_FREQ) \|
	BIT(IIO_CHAN_INFO_HYSTERESIS),
	.scan_index = CHANNEL_SCAN_INDEX_ILLUM,
	}
	};

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

	/* Channel read_raw handler */
	static int als_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2,
	long mask)
	{
	struct als_state *als_state = iio_priv(indio_dev);
	int report_id = -1;
	u32 address;
	int ret_type;

	*val = 0;
	*val2 = 0;
	switch (mask) {
	case 0:
	switch (chan->scan_index) {
	case CHANNEL_SCAN_INDEX_INTENSITY:
	case CHANNEL_SCAN_INDEX_ILLUM:
	report_id = als_state->als_illum.report_id;
	address =
	HID_USAGE_SENSOR_LIGHT_ILLUM;
	break;
	default:
	report_id = -1;
	break;
	}
	if (report_id >= 0) {
	hid_sensor_power_state(&als_state->common_attributes,
	true);
	*val = sensor_hub_input_attr_get_raw_value(
	als_state->common_attributes.hsdev,
	HID_USAGE_SENSOR_ALS, address,
	report_id,
	SENSOR_HUB_SYNC);
	hid_sensor_power_state(&als_state->common_attributes,
	false);
	} else {
	*val = 0;
	return -EINVAL;
	}
	ret_type = IIO_VAL_INT;
	break;
	case IIO_CHAN_INFO_SCALE:
	*val = als_state->scale_pre_decml;
	*val2 = als_state->scale_post_decml;
	ret_type = als_state->scale_precision;
	break;
	case IIO_CHAN_INFO_OFFSET:
	*val = als_state->value_offset;
	ret_type = IIO_VAL_INT;
	break;
	case IIO_CHAN_INFO_SAMP_FREQ:
	ret_type = hid_sensor_read_samp_freq_value(
	&als_state->common_attributes, val, val2);
	break;
	case IIO_CHAN_INFO_HYSTERESIS:
	ret_type = hid_sensor_read_raw_hyst_value(
	&als_state->common_attributes, val, val2);
	break;
	default:
	ret_type = -EINVAL;
	break;
	}

	return ret_type;
	}

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

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

	return ret;
	}

	static const struct iio_info als_info = {
	.driver_module = THIS_MODULE,
	.read_raw = &als_read_raw,
	.write_raw = &als_write_raw,
	};

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

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

	dev_dbg(&indio_dev->dev, "als_proc_event\n");
	if (atomic_read(&als_state->common_attributes.data_ready))
	hid_sensor_push_data(indio_dev,
	&als_state->illum,
	sizeof(als_state->illum));

	return 0;
	}

	/* Capture samples in local storage */
	static int als_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 als_state *als_state = iio_priv(indio_dev);
	int ret = -EINVAL;
	u32 sample_data = (u32 )raw_data;

	switch (usage_id) {
	case HID_USAGE_SENSOR_LIGHT_ILLUM:
	als_state->illum[CHANNEL_SCAN_INDEX_INTENSITY] = sample_data;
	als_state->illum[CHANNEL_SCAN_INDEX_ILLUM] = sample_data;
	ret = 0;
	break;
	default:
	break;
	}

	return ret;
	}

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

	ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
	usage_id,
	HID_USAGE_SENSOR_LIGHT_ILLUM,
	&st->als_illum);
	if (ret < 0)
	return ret;
	als_adjust_channel_bit_mask(channels, CHANNEL_SCAN_INDEX_INTENSITY,
	st->als_illum.size);
	als_adjust_channel_bit_mask(channels, CHANNEL_SCAN_INDEX_ILLUM,
	st->als_illum.size);

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

	st->scale_precision = hid_sensor_format_scale(
	HID_USAGE_SENSOR_ALS,
	&st->als_illum,
	&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_LIGHT,
	&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 ret;
	}

	/* Function to initialize the processing for usage id */
	static int hid_als_probe(struct platform_device *pdev)
	{
	int ret = 0;
	static const char *name = "als";
	struct iio_dev *indio_dev;
	struct als_state *als_state;
	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;

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

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

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

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

	ret = als_parse_report(pdev, hsdev,
	(struct iio_chan_spec *)indio_dev->channels,
	HID_USAGE_SENSOR_ALS, als_state);
	if (ret) {
	dev_err(&pdev->dev, "failed to setup attributes\n");
	goto error_free_dev_mem;
	}

	indio_dev->num_channels =
	ARRAY_SIZE(als_channels);
	indio_dev->dev.parent = &pdev->dev;
	indio_dev->info = &als_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");
	goto error_free_dev_mem;
	}
	atomic_set(&als_state->common_attributes.data_ready, 0);
	ret = hid_sensor_setup_trigger(indio_dev, name,
	&als_state->common_attributes);
	if (ret < 0) {
	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;
	}

	als_state->callbacks.send_event = als_proc_event;
	als_state->callbacks.capture_sample = als_capture_sample;
	als_state->callbacks.pdev = pdev;
	ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_ALS,
	&als_state->callbacks);
	if (ret < 0) {
	dev_err(&pdev->dev, "callback reg failed\n");
	goto error_iio_unreg;
	}

	return ret;

	error_iio_unreg:
	iio_device_unregister(indio_dev);
	error_remove_trigger:
	hid_sensor_remove_trigger(&als_state->common_attributes);
	error_unreg_buffer_funcs:
	iio_triggered_buffer_cleanup(indio_dev);
	error_free_dev_mem:
	kfree(indio_dev->channels);
	return ret;
	}

	/* Function to deinitialize the processing for usage id */
	static int hid_als_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 als_state *als_state = iio_priv(indio_dev);

	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_ALS);
	iio_device_unregister(indio_dev);
	hid_sensor_remove_trigger(&als_state->common_attributes);
	iio_triggered_buffer_cleanup(indio_dev);
	kfree(indio_dev->channels);

	return 0;
	}

	static const struct platform_device_id hid_als_ids[] = {
	{
	/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
	.name = "HID-SENSOR-200041",
	},
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(platform, hid_als_ids);

	static struct platform_driver hid_als_platform_driver = {
	.id_table = hid_als_ids,
	.driver = {
	.name = KBUILD_MODNAME,
	.pm = &hid_sensor_pm_ops,
	},
	.probe = hid_als_probe,
	.remove = hid_als_remove,
	};
	module_platform_driver(hid_als_platform_driver);

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