/*
   * 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 gyro_3d_channel {
  	CHANNEL_SCAN_INDEX_X,
  	CHANNEL_SCAN_INDEX_Y,
  	CHANNEL_SCAN_INDEX_Z,
  	GYRO_3D_CHANNEL_MAX,
  };
  
  struct gyro_3d_state {
  	struct hid_sensor_hub_callbacks callbacks;

  	struct hid_sensor_common common_attributes;

  	struct hid_sensor_hub_attribute_info gyro[GYRO_3D_CHANNEL_MAX];
  	u32 gyro_val[GYRO_3D_CHANNEL_MAX];

  	int scale_pre_decml;
  	int scale_post_decml;
  	int scale_precision;
  	int value_offset;

  };
  
  static const u32 gyro_3d_addresses[GYRO_3D_CHANNEL_MAX] = {
  	HID_USAGE_SENSOR_ANGL_VELOCITY_X_AXIS,
  	HID_USAGE_SENSOR_ANGL_VELOCITY_Y_AXIS,
  	HID_USAGE_SENSOR_ANGL_VELOCITY_Z_AXIS
  };
  
  /* Channel definitions */
  static const struct iio_chan_spec gyro_3d_channels[] = {
  	{
  		.type = IIO_ANGL_VEL,
  		.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),

  		.scan_index = CHANNEL_SCAN_INDEX_X,
  	}, {
  		.type = IIO_ANGL_VEL,
  		.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),

  		.scan_index = CHANNEL_SCAN_INDEX_Y,
  	}, {
  		.type = IIO_ANGL_VEL,
  		.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),

  		.scan_index = CHANNEL_SCAN_INDEX_Z,
  	}
  };
  
  /* Adjust channel real bits based on report descriptor */
  static void gyro_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 gyro_3d_read_raw(struct iio_dev *indio_dev,
  			      struct iio_chan_spec const *chan,
  			      int *val, int *val2,
  			      long mask)
  {
  	struct gyro_3d_state *gyro_state = iio_priv(indio_dev);
  	int report_id = -1;
  	u32 address;

  	int ret_type;
  
  	*val = 0;
  	*val2 = 0;
  	switch (mask) {
  	case 0:

  		hid_sensor_power_state(&gyro_state->common_attributes, true);

  		report_id = gyro_state->gyro[chan->scan_index].report_id;
  		address = gyro_3d_addresses[chan->scan_index];
  		if (report_id >= 0)
  			*val = sensor_hub_input_attr_get_raw_value(

  					gyro_state->common_attributes.hsdev,
  					HID_USAGE_SENSOR_GYRO_3D, address,

  					report_id,
  					SENSOR_HUB_SYNC);

  		else {
  			*val = 0;

  			hid_sensor_power_state(&gyro_state->common_attributes,
  						false);

  			return -EINVAL;
  		}

  		hid_sensor_power_state(&gyro_state->common_attributes, false);

  		ret_type = IIO_VAL_INT;
  		break;
  	case IIO_CHAN_INFO_SCALE:

  		*val = gyro_state->scale_pre_decml;
  		*val2 = gyro_state->scale_post_decml;
  		ret_type = gyro_state->scale_precision;

  		break;
  	case IIO_CHAN_INFO_OFFSET:

  		*val = gyro_state->value_offset;

  		ret_type = IIO_VAL_INT;
  		break;
  	case IIO_CHAN_INFO_SAMP_FREQ:

  		ret_type = hid_sensor_read_samp_freq_value(

  			&gyro_state->common_attributes, val, val2);

  		break;
  	case IIO_CHAN_INFO_HYSTERESIS:

  		ret_type = hid_sensor_read_raw_hyst_value(

  			&gyro_state->common_attributes, val, val2);

  		break;
  	default:
  		ret_type = -EINVAL;
  		break;
  	}
  
  	return ret_type;
  }
  
  /* Channel write_raw handler */
  static int gyro_3d_write_raw(struct iio_dev *indio_dev,
  			       struct iio_chan_spec const *chan,
  			       int val,
  			       int val2,
  			       long mask)
  {
  	struct gyro_3d_state *gyro_state = iio_priv(indio_dev);
  	int ret = 0;
  
  	switch (mask) {
  	case IIO_CHAN_INFO_SAMP_FREQ:
  		ret = hid_sensor_write_samp_freq_value(
  				&gyro_state->common_attributes, val, val2);
  		break;
  	case IIO_CHAN_INFO_HYSTERESIS:
  		ret = hid_sensor_write_raw_hyst_value(
  				&gyro_state->common_attributes, val, val2);
  		break;
  	default:
  		ret = -EINVAL;
  	}
  
  	return ret;
  }

  static const struct iio_info gyro_3d_info = {
  	.driver_module = THIS_MODULE,
  	.read_raw = &gyro_3d_read_raw,
  	.write_raw = &gyro_3d_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
  ");

  	iio_push_to_buffers(indio_dev, data);

  }
  
  /* Callback handler to send event after all samples are received and captured */
  static int gyro_3d_proc_event(struct hid_sensor_hub_device *hsdev,
  				unsigned usage_id,
  				void *priv)
  {
  	struct iio_dev *indio_dev = platform_get_drvdata(priv);
  	struct gyro_3d_state *gyro_state = iio_priv(indio_dev);

  	dev_dbg(&indio_dev->dev, "gyro_3d_proc_event
  ");
  	if (atomic_read(&gyro_state->common_attributes.data_ready))

  		hid_sensor_push_data(indio_dev,

  				gyro_state->gyro_val,

  				sizeof(gyro_state->gyro_val));
  
  	return 0;
  }
  
  /* Capture samples in local storage */
  static int gyro_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 gyro_3d_state *gyro_state = iio_priv(indio_dev);
  	int offset;
  	int ret = -EINVAL;
  
  	switch (usage_id) {
  	case HID_USAGE_SENSOR_ANGL_VELOCITY_X_AXIS:
  	case HID_USAGE_SENSOR_ANGL_VELOCITY_Y_AXIS:
  	case HID_USAGE_SENSOR_ANGL_VELOCITY_Z_AXIS:
  		offset = usage_id - HID_USAGE_SENSOR_ANGL_VELOCITY_X_AXIS;
  		gyro_state->gyro_val[CHANNEL_SCAN_INDEX_X + offset] =
  						*(u32 *)raw_data;
  		ret = 0;
  	break;
  	default:
  		break;
  	}
  
  	return ret;
  }
  
  /* Parse report which is specific to an usage id*/
  static int gyro_3d_parse_report(struct platform_device *pdev,
  				struct hid_sensor_hub_device *hsdev,
  				struct iio_chan_spec *channels,
  				unsigned usage_id,
  				struct gyro_3d_state *st)
  {
  	int ret;
  	int i;
  
  	for (i = 0; i <= CHANNEL_SCAN_INDEX_Z; ++i) {
  		ret = sensor_hub_input_get_attribute_info(hsdev,
  				HID_INPUT_REPORT,
  				usage_id,
  				HID_USAGE_SENSOR_ANGL_VELOCITY_X_AXIS + i,
  				&st->gyro[CHANNEL_SCAN_INDEX_X + i]);
  		if (ret < 0)
  			break;
  		gyro_3d_adjust_channel_bit_mask(channels,
  				CHANNEL_SCAN_INDEX_X + i,
  				st->gyro[CHANNEL_SCAN_INDEX_X + i].size);
  	}
  	dev_dbg(&pdev->dev, "gyro_3d %x:%x, %x:%x, %x:%x
  ",
  			st->gyro[0].index,
  			st->gyro[0].report_id,
  			st->gyro[1].index, st->gyro[1].report_id,
  			st->gyro[2].index, st->gyro[2].report_id);

  	st->scale_precision = hid_sensor_format_scale(
  				HID_USAGE_SENSOR_GYRO_3D,
  				&st->gyro[CHANNEL_SCAN_INDEX_X],
  				&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_ANGL_VELOCITY,
  			&st->common_attributes.sensitivity);
  		dev_dbg(&pdev->dev, "Sensitivity index:report %d:%d
  ",
  			st->common_attributes.sensitivity.index,
  			st->common_attributes.sensitivity.report_id);
  	}

  	return ret;
  }
  
  /* Function to initialize the processing for usage id */

  static int hid_gyro_3d_probe(struct platform_device *pdev)

  {
  	int ret = 0;
  	static const char *name = "gyro_3d";
  	struct iio_dev *indio_dev;
  	struct gyro_3d_state *gyro_state;
  	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;

  	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*gyro_state));
  	if (!indio_dev)
  		return -ENOMEM;

  	platform_set_drvdata(pdev, indio_dev);
  
  	gyro_state = iio_priv(indio_dev);
  	gyro_state->common_attributes.hsdev = hsdev;
  	gyro_state->common_attributes.pdev = pdev;
  
  	ret = hid_sensor_parse_common_attributes(hsdev,
  						HID_USAGE_SENSOR_GYRO_3D,
  						&gyro_state->common_attributes);
  	if (ret) {
  		dev_err(&pdev->dev, "failed to setup common attributes
  ");

  		return ret;

  	}

  	indio_dev->channels = kmemdup(gyro_3d_channels,
  				      sizeof(gyro_3d_channels), GFP_KERNEL);
  	if (!indio_dev->channels) {

  		dev_err(&pdev->dev, "failed to duplicate channels
  ");

  		return -ENOMEM;

  	}

  	ret = gyro_3d_parse_report(pdev, hsdev,
  				   (struct iio_chan_spec *)indio_dev->channels,
  				   HID_USAGE_SENSOR_GYRO_3D, gyro_state);

  	if (ret) {
  		dev_err(&pdev->dev, "failed to setup attributes
  ");
  		goto error_free_dev_mem;
  	}

  	indio_dev->num_channels = ARRAY_SIZE(gyro_3d_channels);
  	indio_dev->dev.parent = &pdev->dev;
  	indio_dev->info = &gyro_3d_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
  ");
  		goto error_free_dev_mem;
  	}

  	atomic_set(&gyro_state->common_attributes.data_ready, 0);

  	ret = hid_sensor_setup_trigger(indio_dev, name,
  					&gyro_state->common_attributes);
  	if (ret < 0) {
  		dev_err(&pdev->dev, "trigger setup failed
  ");
  		goto error_unreg_buffer_funcs;
  	}
  
  	ret = iio_device_register(indio_dev);
  	if (ret) {
  		dev_err(&pdev->dev, "device register failed
  ");
  		goto error_remove_trigger;
  	}
  
  	gyro_state->callbacks.send_event = gyro_3d_proc_event;
  	gyro_state->callbacks.capture_sample = gyro_3d_capture_sample;
  	gyro_state->callbacks.pdev = pdev;
  	ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_GYRO_3D,
  					&gyro_state->callbacks);
  	if (ret < 0) {
  		dev_err(&pdev->dev, "callback reg failed
  ");
  		goto error_iio_unreg;
  	}
  
  	return ret;
  
  error_iio_unreg:
  	iio_device_unregister(indio_dev);
  error_remove_trigger:

  	hid_sensor_remove_trigger(&gyro_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_gyro_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 gyro_3d_state *gyro_state = iio_priv(indio_dev);

  
  	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_GYRO_3D);
  	iio_device_unregister(indio_dev);

  	hid_sensor_remove_trigger(&gyro_state->common_attributes);

  	iio_triggered_buffer_cleanup(indio_dev);
  	kfree(indio_dev->channels);

  
  	return 0;
  }

  static const struct platform_device_id hid_gyro_3d_ids[] = {

  	{
  		/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
  		.name = "HID-SENSOR-200076",
  	},
  	{ /* sentinel */ }
  };
  MODULE_DEVICE_TABLE(platform, hid_gyro_3d_ids);

  static struct platform_driver hid_gyro_3d_platform_driver = {

  	.id_table = hid_gyro_3d_ids,

  	.driver = {

  		.name	= KBUILD_MODNAME,

  		.pm	= &hid_sensor_pm_ops,

  	},
  	.probe		= hid_gyro_3d_probe,
  	.remove		= hid_gyro_3d_remove,
  };
  module_platform_driver(hid_gyro_3d_platform_driver);
  
  MODULE_DESCRIPTION("HID Sensor Gyroscope 3D");
  MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@intel.com>");
  MODULE_LICENSE("GPL");