text: // SPDX-License-Identifier: GPL-2.0-only
  /*
   * HID Sensors Driver
   * Copyright (c) 2012, Intel Corporation.
   */
  #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 "../common/hid-sensors/hid-sensor-trigger.h"
  
  enum magn_3d_channel {
  	CHANNEL_SCAN_INDEX_X,
  	CHANNEL_SCAN_INDEX_Y,
  	CHANNEL_SCAN_INDEX_Z,
  	CHANNEL_SCAN_INDEX_NORTH_MAGN_TILT_COMP,
  	CHANNEL_SCAN_INDEX_NORTH_TRUE_TILT_COMP,
  	CHANNEL_SCAN_INDEX_NORTH_MAGN,
  	CHANNEL_SCAN_INDEX_NORTH_TRUE,
  	CHANNEL_SCAN_INDEX_TIMESTAMP,
  	MAGN_3D_CHANNEL_MAX,
  };
  
  struct common_attributes {
  	int scale_pre_decml;
  	int scale_post_decml;
  	int scale_precision;
  	int value_offset;
  };
  
  struct magn_3d_state {
  	struct hid_sensor_hub_callbacks callbacks;
  	struct hid_sensor_common magn_flux_attributes;
  	struct hid_sensor_common rot_attributes;
  	struct hid_sensor_hub_attribute_info magn[MAGN_3D_CHANNEL_MAX];
  
  	/* dynamically sized array to hold sensor values */
  	u32 *iio_vals;
  	/* array of pointers to sensor value */
  	u32 *magn_val_addr[MAGN_3D_CHANNEL_MAX];
  
  	struct common_attributes magn_flux_attr;
  	struct common_attributes rot_attr;
  	s64 timestamp;
  };
  
  static const u32 magn_3d_addresses[MAGN_3D_CHANNEL_MAX] = {
  	HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS,
  	HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS,
  	HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS,
  	HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH,
  	HID_USAGE_SENSOR_ORIENT_COMP_TRUE_NORTH,
  	HID_USAGE_SENSOR_ORIENT_MAGN_NORTH,
  	HID_USAGE_SENSOR_ORIENT_TRUE_NORTH,
  	HID_USAGE_SENSOR_TIME_TIMESTAMP,
  };
  
  static const u32 magn_3d_sensitivity_addresses[] = {
  	HID_USAGE_SENSOR_DATA_ORIENTATION,
  	HID_USAGE_SENSOR_ORIENT_MAGN_FLUX,
  };
  
  /* Channel definitions */
  static const struct iio_chan_spec magn_3d_channels[] = {
  	{
  		.type = IIO_MAGN,
  		.modified = 1,
  		.channel2 = IIO_MOD_X,
  		.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),
  	}, {
  		.type = IIO_MAGN,
  		.modified = 1,
  		.channel2 = IIO_MOD_Y,
  		.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),
  	}, {
  		.type = IIO_MAGN,
  		.modified = 1,
  		.channel2 = IIO_MOD_Z,
  		.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),
  	}, {
  		.type = IIO_ROT,
  		.modified = 1,
  		.channel2 = IIO_MOD_NORTH_MAGN_TILT_COMP,
  		.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),
  	}, {
  		.type = IIO_ROT,
  		.modified = 1,
  		.channel2 = IIO_MOD_NORTH_TRUE_TILT_COMP,
  		.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),
  	}, {
  		.type = IIO_ROT,
  		.modified = 1,
  		.channel2 = IIO_MOD_NORTH_MAGN,
  		.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),
  	}, {
  		.type = IIO_ROT,
  		.modified = 1,
  		.channel2 = IIO_MOD_NORTH_TRUE,
  		.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),
  	},
  	IIO_CHAN_SOFT_TIMESTAMP(7)
  };
  
  /* Adjust channel real bits based on report descriptor */
  static void magn_3d_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 magn_3d_read_raw(struct iio_dev *indio_dev,
  			      struct iio_chan_spec const *chan,
  			      int *val, int *val2,
  			      long mask)
  {
  	struct magn_3d_state *magn_state = iio_priv(indio_dev);
  	int report_id = -1;
  	u32 address;
  	int ret_type;
  	s32 min;
  
  	*val = 0;
  	*val2 = 0;
  	switch (mask) {
  	case IIO_CHAN_INFO_RAW:
  		hid_sensor_power_state(&magn_state->magn_flux_attributes, true);
  		report_id = magn_state->magn[chan->address].report_id;
  		min = magn_state->magn[chan->address].logical_minimum;
  		address = magn_3d_addresses[chan->address];
  		if (report_id >= 0)
  			*val = sensor_hub_input_attr_get_raw_value(
  				magn_state->magn_flux_attributes.hsdev,
  				HID_USAGE_SENSOR_COMPASS_3D, address,
  				report_id,
  				SENSOR_HUB_SYNC,
  				min < 0);
  		else {
  			*val = 0;
  			hid_sensor_power_state(
  				&magn_state->magn_flux_attributes,
  				false);
  			return -EINVAL;
  		}
  		hid_sensor_power_state(&magn_state->magn_flux_attributes,
  					false);
  		ret_type = IIO_VAL_INT;
  		break;
  	case IIO_CHAN_INFO_SCALE:
  		switch (chan->type) {
  		case IIO_MAGN:
  			*val = magn_state->magn_flux_attr.scale_pre_decml;
  			*val2 = magn_state->magn_flux_attr.scale_post_decml;
  			ret_type = magn_state->magn_flux_attr.scale_precision;
  			break;
  		case IIO_ROT:
  			*val = magn_state->rot_attr.scale_pre_decml;
  			*val2 = magn_state->rot_attr.scale_post_decml;
  			ret_type = magn_state->rot_attr.scale_precision;
  			break;
  		default:
  			ret_type = -EINVAL;
  		}
  		break;
  	case IIO_CHAN_INFO_OFFSET:
  		switch (chan->type) {
  		case IIO_MAGN:
  			*val = magn_state->magn_flux_attr.value_offset;
  			ret_type = IIO_VAL_INT;
  			break;
  		case IIO_ROT:
  			*val = magn_state->rot_attr.value_offset;
  			ret_type = IIO_VAL_INT;
  			break;
  		default:
  			ret_type = -EINVAL;
  		}
  		break;
  	case IIO_CHAN_INFO_SAMP_FREQ:
  		ret_type = hid_sensor_read_samp_freq_value(
  			&magn_state->magn_flux_attributes, val, val2);
  		break;
  	case IIO_CHAN_INFO_HYSTERESIS:
  		switch (chan->type) {
  		case IIO_MAGN:
  			ret_type = hid_sensor_read_raw_hyst_value(
  				&magn_state->magn_flux_attributes, val, val2);
  			break;
  		case IIO_ROT:
  			ret_type = hid_sensor_read_raw_hyst_value(
  				&magn_state->rot_attributes, val, val2);
  			break;
  		default:
  			ret_type = -EINVAL;
  		}
  		break;
  	default:
  		ret_type = -EINVAL;
  		break;
  	}
  
  	return ret_type;
  }
  
  /* Channel write_raw handler */
  static int magn_3d_write_raw(struct iio_dev *indio_dev,
  			       struct iio_chan_spec const *chan,
  			       int val,
  			       int val2,
  			       long mask)
  {
  	struct magn_3d_state *magn_state = iio_priv(indio_dev);
  	int ret = 0;
  
  	switch (mask) {
  	case IIO_CHAN_INFO_SAMP_FREQ:
  		ret = hid_sensor_write_samp_freq_value(
  				&magn_state->magn_flux_attributes, val, val2);
  		break;
  	case IIO_CHAN_INFO_HYSTERESIS:
  		switch (chan->type) {
  		case IIO_MAGN:
  			ret = hid_sensor_write_raw_hyst_value(
  				&magn_state->magn_flux_attributes, val, val2);
  			break;
  		case IIO_ROT:
  			ret = hid_sensor_write_raw_hyst_value(
  				&magn_state->rot_attributes, val, val2);
  			break;
  		default:
  			ret = -EINVAL;
  		}
  		break;
  	default:
  		ret = -EINVAL;
  	}
  
  	return ret;
  }
  
  static const struct iio_info magn_3d_info = {
  	.read_raw = &magn_3d_read_raw,
  	.write_raw = &magn_3d_write_raw,
  };
  
  /* Callback handler to send event after all samples are received and captured */
  static int magn_3d_proc_event(struct hid_sensor_hub_device *hsdev,
  				unsigned usage_id,
  				void *priv)
  {
  	struct iio_dev *indio_dev = platform_get_drvdata(priv);
  	struct magn_3d_state *magn_state = iio_priv(indio_dev);
  
  	dev_dbg(&indio_dev->dev, "magn_3d_proc_event\n");
  	if (atomic_read(&magn_state->magn_flux_attributes.data_ready)) {
  		if (!magn_state->timestamp)
  			magn_state->timestamp = iio_get_time_ns(indio_dev);
  
  		iio_push_to_buffers_with_timestamp(indio_dev,
  						   magn_state->iio_vals,
  						   magn_state->timestamp);
  		magn_state->timestamp = 0;
  	}
  
  	return 0;
  }
  
  /* Capture samples in local storage */
  static int magn_3d_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 magn_3d_state *magn_state = iio_priv(indio_dev);
  	int offset;
  	int ret = 0;
  	u32 *iio_val = NULL;
  
  	switch (usage_id) {
  	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS:
  	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS:
  	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS:
  		offset = (usage_id - HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS)
  				+ CHANNEL_SCAN_INDEX_X;
  	break;
  	case HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH:
  	case HID_USAGE_SENSOR_ORIENT_COMP_TRUE_NORTH:
  	case HID_USAGE_SENSOR_ORIENT_MAGN_NORTH:
  	case HID_USAGE_SENSOR_ORIENT_TRUE_NORTH:
  		offset = (usage_id - HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH)
  				+ CHANNEL_SCAN_INDEX_NORTH_MAGN_TILT_COMP;
  	break;
  	case HID_USAGE_SENSOR_TIME_TIMESTAMP:
  		magn_state->timestamp =
  			hid_sensor_convert_timestamp(&magn_state->magn_flux_attributes,
  						     *(s64 *)raw_data);
  		return ret;
  	default:
  		return -EINVAL;
  	}
  
  	iio_val = magn_state->magn_val_addr[offset];
  
  	if (iio_val != NULL)
  		*iio_val = *((u32 *)raw_data);
  	else
  		ret = -EINVAL;
  
  	return ret;
  }
  
  /* Parse report which is specific to an usage id*/
  static int magn_3d_parse_report(struct platform_device *pdev,
  				struct hid_sensor_hub_device *hsdev,
  				struct iio_chan_spec **channels,
  				int *chan_count,
  				unsigned usage_id,
  				struct magn_3d_state *st)
  {
  	int i;
  	int attr_count = 0;
  	struct iio_chan_spec *_channels;
  
  	/* Scan for each usage attribute supported */
  	for (i = 0; i < MAGN_3D_CHANNEL_MAX; i++) {
  		int status;
  		u32 address = magn_3d_addresses[i];
  
  		/* Check if usage attribute exists in the sensor hub device */
  		status = sensor_hub_input_get_attribute_info(hsdev,
  			HID_INPUT_REPORT,
  			usage_id,
  			address,
  			&(st->magn[i]));
  		if (!status)
  			attr_count++;
  	}
  
  	if (attr_count <= 0) {
  		dev_err(&pdev->dev,
  			"failed to find any supported usage attributes in report\n");
  		return  -EINVAL;
  	}
  
  	dev_dbg(&pdev->dev, "magn_3d Found %d usage attributes\n",
  			attr_count);
  	dev_dbg(&pdev->dev, "magn_3d X: %x:%x Y: %x:%x Z: %x:%x\n",
  			st->magn[0].index,
  			st->magn[0].report_id,
  			st->magn[1].index, st->magn[1].report_id,
  			st->magn[2].index, st->magn[2].report_id);
  
  	/* Setup IIO channel array */
  	_channels = devm_kcalloc(&pdev->dev, attr_count,
  				sizeof(struct iio_chan_spec),
  				GFP_KERNEL);
  	if (!_channels) {
  		dev_err(&pdev->dev,
  			"failed to allocate space for iio channels\n");
  		return -ENOMEM;
  	}
  
  	/* attr_count include timestamp channel, and the iio_vals should be aligned to 8byte */
  	st->iio_vals = devm_kcalloc(&pdev->dev,
  				    ((attr_count + 1) % 2 + (attr_count + 1) / 2) * 2,
  				    sizeof(u32), GFP_KERNEL);
  	if (!st->iio_vals) {
  		dev_err(&pdev->dev,
  			"failed to allocate space for iio values array\n");
  		return -ENOMEM;
  	}
  
  	for (i = 0, *chan_count = 0;
  	i < MAGN_3D_CHANNEL_MAX && *chan_count < attr_count;
  	i++){
  		if (st->magn[i].index >= 0) {
  			/* Setup IIO channel struct */
  			(_channels[*chan_count]) = magn_3d_channels[i];
  			(_channels[*chan_count]).scan_index = *chan_count;
  			(_channels[*chan_count]).address = i;
  
  			if (i != CHANNEL_SCAN_INDEX_TIMESTAMP) {
  				/* Set magn_val_addr to iio value address */
  				st->magn_val_addr[i] = &st->iio_vals[*chan_count];
  				magn_3d_adjust_channel_bit_mask(_channels,
  								*chan_count,
  								st->magn[i].size);
  			}
  			(*chan_count)++;
  		}
  	}
  
  	if (*chan_count <= 0) {
  		dev_err(&pdev->dev,
  			"failed to find any magnetic channels setup\n");
  		return -EINVAL;
  	}
  
  	*channels = _channels;
  
  	dev_dbg(&pdev->dev, "magn_3d Setup %d IIO channels\n",
  			*chan_count);
  
  	st->magn_flux_attr.scale_precision = hid_sensor_format_scale(
  				HID_USAGE_SENSOR_COMPASS_3D,
  				&st->magn[CHANNEL_SCAN_INDEX_X],
  				&st->magn_flux_attr.scale_pre_decml,
  				&st->magn_flux_attr.scale_post_decml);
  	st->rot_attr.scale_precision
  		= hid_sensor_format_scale(
  			HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH,
  			&st->magn[CHANNEL_SCAN_INDEX_NORTH_MAGN_TILT_COMP],
  			&st->rot_attr.scale_pre_decml,
  			&st->rot_attr.scale_post_decml);
  
  	if (st->rot_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_ORIENT_COMP_MAGN_NORTH,
  			&st->rot_attributes.sensitivity);
  		dev_dbg(&pdev->dev, "Sensitivity index:report %d:%d\n",
  			st->rot_attributes.sensitivity.index,
  			st->rot_attributes.sensitivity.report_id);
  	}
  
  	return 0;
  }
  
  /* Function to initialize the processing for usage id */
  static int hid_magn_3d_probe(struct platform_device *pdev)
  {
  	int ret = 0;
  	static char *name = "magn_3d";
  	struct iio_dev *indio_dev;
  	struct magn_3d_state *magn_state;
  	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
  	struct iio_chan_spec *channels;
  	int chan_count = 0;
  
  	indio_dev = devm_iio_device_alloc(&pdev->dev,
  					  sizeof(struct magn_3d_state));
  	if (indio_dev == NULL)
  		return -ENOMEM;
  
  	platform_set_drvdata(pdev, indio_dev);
  
  	magn_state = iio_priv(indio_dev);
  	magn_state->magn_flux_attributes.hsdev = hsdev;
  	magn_state->magn_flux_attributes.pdev = pdev;
  
  	ret = hid_sensor_parse_common_attributes(hsdev,
  				HID_USAGE_SENSOR_COMPASS_3D,
  				&magn_state->magn_flux_attributes,
  				magn_3d_sensitivity_addresses,
  				ARRAY_SIZE(magn_3d_sensitivity_addresses));
  	if (ret) {
  		dev_err(&pdev->dev, "failed to setup common attributes\n");
  		return ret;
  	}
  	magn_state->rot_attributes = magn_state->magn_flux_attributes;
  	/* sensitivity of rot_attribute is not the same as magn_flux_attributes */
  	magn_state->rot_attributes.sensitivity.index = -1;
  
  	ret = magn_3d_parse_report(pdev, hsdev,
  				&channels, &chan_count,
  				HID_USAGE_SENSOR_COMPASS_3D, magn_state);
  	if (ret) {
  		dev_err(&pdev->dev, "failed to parse report\n");
  		return ret;
  	}
  
  	indio_dev->channels = channels;
  	indio_dev->num_channels = chan_count;
  	indio_dev->info = &magn_3d_info;
  	indio_dev->name = name;
  	indio_dev->modes = INDIO_DIRECT_MODE;
  
  	atomic_set(&magn_state->magn_flux_attributes.data_ready, 0);
  
  	ret = hid_sensor_setup_trigger(indio_dev, name,
  					&magn_state->magn_flux_attributes);
  	if (ret < 0) {
  		dev_err(&pdev->dev, "trigger setup failed\n");
  		return ret;
  	}
  
  	ret = iio_device_register(indio_dev);
  	if (ret) {
  		dev_err(&pdev->dev, "device register failed\n");
  		goto error_remove_trigger;
  	}
  
  	magn_state->callbacks.send_event = magn_3d_proc_event;
  	magn_state->callbacks.capture_sample = magn_3d_capture_sample;
  	magn_state->callbacks.pdev = pdev;
  	ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_COMPASS_3D,
  					&magn_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(indio_dev, &magn_state->magn_flux_attributes);
  	return ret;
  }
  
  /* Function to deinitialize the processing for usage id */
  static int hid_magn_3d_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 magn_3d_state *magn_state = iio_priv(indio_dev);
  
  	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_COMPASS_3D);
  	iio_device_unregister(indio_dev);
  	hid_sensor_remove_trigger(indio_dev, &magn_state->magn_flux_attributes);
  
  	return 0;
  }
  
  static const struct platform_device_id hid_magn_3d_ids[] = {
  	{
  		/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
  		.name = "HID-SENSOR-200083",
  	},
  	{ /* sentinel */ }
  };
  MODULE_DEVICE_TABLE(platform, hid_magn_3d_ids);
  
  static struct platform_driver hid_magn_3d_platform_driver = {
  	.id_table = hid_magn_3d_ids,
  	.driver = {
  		.name	= KBUILD_MODNAME,
  		.pm	= &hid_sensor_pm_ops,
  	},
  	.probe		= hid_magn_3d_probe,
  	.remove		= hid_magn_3d_remove,
  };
  module_platform_driver(hid_magn_3d_platform_driver);
  
  MODULE_DESCRIPTION("HID Sensor Magnetometer 3D");
  MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@intel.com>");
  MODULE_LICENSE("GPL");
  