Quelle  hid-sensor-rotation.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-only
/*
 * HID Sensors Driver
 * Copyright (c) 2014, Intel Corporation.
 */

#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/mod_devicetable.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"

struct dev_rot_state {
 struct hid_sensor_hub_callbacks callbacks;
 struct hid_sensor_common common_attributes;
 struct hid_sensor_hub_attribute_info quaternion;
 struct {
  s32 sampled_vals[4];
  aligned_s64 timestamp;
 } scan;
 int scale_pre_decml;
 int scale_post_decml;
 int scale_precision;
 int value_offset;
 s64 timestamp;
};

static const u32 rotation_sensitivity_addresses[] = {
 HID_USAGE_SENSOR_DATA_ORIENTATION,
 HID_USAGE_SENSOR_ORIENT_QUATERNION,
};

/* 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),
  .scan_index = 0
 },
 IIO_CHAN_SOFT_TIMESTAMP(1)
};

/* 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->scan.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 = {
 .read_raw_multi = &dev_rot_read_raw,
 .write_raw = &dev_rot_write_raw,
};

/* 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)) {
  if (!rot_state->timestamp)
   rot_state->timestamp = iio_get_time_ns(indio_dev);

  iio_push_to_buffers_with_timestamp(indio_dev, &rot_state->scan,
         rot_state->timestamp);

  rot_state->timestamp = 0;
 }

 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) {
  if (raw_len / 4 == sizeof(s16)) {
   rot_state->scan.sampled_vals[0] = ((s16 *)raw_data)[0];
   rot_state->scan.sampled_vals[1] = ((s16 *)raw_data)[1];
   rot_state->scan.sampled_vals[2] = ((s16 *)raw_data)[2];
   rot_state->scan.sampled_vals[3] = ((s16 *)raw_data)[3];
  } else {
   memcpy(&rot_state->scan.sampled_vals, raw_data,
          sizeof(rot_state->scan.sampled_vals));
  }

  dev_dbg(&indio_dev->dev, "Recd Quat len:%zu::%zu\n", raw_len,
   sizeof(rot_state->scan.sampled_vals));
 } else if (usage_id == HID_USAGE_SENSOR_TIME_TIMESTAMP) {
  rot_state->timestamp = hid_sensor_convert_timestamp(&rot_state->common_attributes,
            *(s64 *)raw_data);
 }

 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);

 return 0;
}

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

 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,
       rotation_sensitivity_addresses,
       ARRAY_SIZE(rotation_sensitivity_addresses));
 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->info = &dev_rot_info;
 indio_dev->name = name;
 indio_dev->modes = INDIO_DIRECT_MODE;

 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");
  return ret;
 }

 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(indio_dev, &rot_state->common_attributes);
 return ret;
}

/* Function to deinitialize the processing for usage id */
static void hid_dev_rot_remove(struct platform_device *pdev)
{
 struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 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(indio_dev, &rot_state->common_attributes);
}

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",
 },
 { }
};
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 ");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("IIO_HID");