Quelle  hid-sensor-press.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/slab.h>
#include <linux/hid-sensor-hub.h>
#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include "../common/hid-sensors/hid-sensor-trigger.h"

enum {
 CHANNEL_SCAN_INDEX_PRESSURE,
 CHANNEL_SCAN_INDEX_TIMESTAMP,
};

struct press_state {
 struct hid_sensor_hub_callbacks callbacks;
 struct hid_sensor_common common_attributes;
 struct hid_sensor_hub_attribute_info press_attr;
 struct {
  u32 press_data;
  aligned_s64 timestamp;
 } scan;
 int scale_pre_decml;
 int scale_post_decml;
 int scale_precision;
 int value_offset;
 s64 timestamp;
};

static const u32 press_sensitivity_addresses[] = {
 HID_USAGE_SENSOR_DATA_ATMOSPHERIC_PRESSURE,
 HID_USAGE_SENSOR_ATMOSPHERIC_PRESSURE
};

/* Channel definitions */
static const struct iio_chan_spec press_channels[] = {
 {
  .type = IIO_PRESSURE,
  .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_PRESSURE,
 },
 IIO_CHAN_SOFT_TIMESTAMP(CHANNEL_SCAN_INDEX_TIMESTAMP)

};

/* Adjust channel real bits based on report descriptor */
static void press_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 press_read_raw(struct iio_dev *indio_dev,
         struct iio_chan_spec const *chan,
         int *val, int *val2,
         long mask)
{
 struct press_state *press_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:
  switch (chan->scan_index) {
  case  CHANNEL_SCAN_INDEX_PRESSURE:
   report_id = press_state->press_attr.report_id;
   min = press_state->press_attr.logical_minimum;
   address = HID_USAGE_SENSOR_ATMOSPHERIC_PRESSURE;
   break;
  default:
   report_id = -1;
   break;
  }
  if (report_id >= 0) {
   hid_sensor_power_state(&press_state->common_attributes,
      true);
   *val = sensor_hub_input_attr_get_raw_value(
    press_state->common_attributes.hsdev,
    HID_USAGE_SENSOR_PRESSURE, address,
    report_id,
    SENSOR_HUB_SYNC,
    min < 0);
   hid_sensor_power_state(&press_state->common_attributes,
      false);
  } else {
   *val = 0;
   return -EINVAL;
  }
  ret_type = IIO_VAL_INT;
  break;
 case IIO_CHAN_INFO_SCALE:
  *val = press_state->scale_pre_decml;
  *val2 = press_state->scale_post_decml;
  ret_type = press_state->scale_precision;
  break;
 case IIO_CHAN_INFO_OFFSET:
  *val = press_state->value_offset;
  ret_type = IIO_VAL_INT;
  break;
 case IIO_CHAN_INFO_SAMP_FREQ:
  ret_type = hid_sensor_read_samp_freq_value(
    &press_state->common_attributes, val, val2);
  break;
 case IIO_CHAN_INFO_HYSTERESIS:
  ret_type = hid_sensor_read_raw_hyst_value(
    &press_state->common_attributes, val, val2);
  break;
 default:
  ret_type = -EINVAL;
  break;
 }

 return ret_type;
}

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

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

 return ret;
}

static const struct iio_info press_info = {
 .read_raw = &press_read_raw,
 .write_raw = &press_write_raw,
};

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

 dev_dbg(&indio_dev->dev, "press_proc_event\n");
 if (atomic_read(&press_state->common_attributes.data_ready)) {
  if (!press_state->timestamp)
   press_state->timestamp = iio_get_time_ns(indio_dev);

  iio_push_to_buffers_with_ts(indio_dev, &press_state->scan,
         sizeof(press_state->scan),
         press_state->timestamp);
 }

 return 0;
}

/* Capture samples in local storage */
static int press_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 press_state *press_state = iio_priv(indio_dev);
 int ret = -EINVAL;

 switch (usage_id) {
 case HID_USAGE_SENSOR_ATMOSPHERIC_PRESSURE:
  press_state->scan.press_data = *(u32 *)raw_data;
  ret = 0;
  break;
 case HID_USAGE_SENSOR_TIME_TIMESTAMP:
  press_state->timestamp = hid_sensor_convert_timestamp(
   &press_state->common_attributes, *(s64 *)raw_data);
  break;
 default:
  break;
 }

 return ret;
}

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

 ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
   usage_id,
   HID_USAGE_SENSOR_ATMOSPHERIC_PRESSURE,
   &st->press_attr);
 if (ret < 0)
  return ret;
 press_adjust_channel_bit_mask(channels, CHANNEL_SCAN_INDEX_PRESSURE,
     st->press_attr.size);

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

 st->scale_precision = hid_sensor_format_scale(
    HID_USAGE_SENSOR_PRESSURE,
    &st->press_attr,
    &st->scale_pre_decml, &st->scale_post_decml);

 return ret;
}

/* Function to initialize the processing for usage id */
static int hid_press_probe(struct platform_device *pdev)
{
 struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 int ret = 0;
 static const char *name = "press";
 struct iio_dev *indio_dev;
 struct press_state *press_state;

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

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

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

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

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

 indio_dev->num_channels =
    ARRAY_SIZE(press_channels);
 indio_dev->info = &press_info;
 indio_dev->name = name;
 indio_dev->modes = INDIO_DIRECT_MODE;

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

 ret = hid_sensor_setup_trigger(indio_dev, name,
    &press_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;
 }

 press_state->callbacks.send_event = press_proc_event;
 press_state->callbacks.capture_sample = press_capture_sample;
 press_state->callbacks.pdev = pdev;
 ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_PRESSURE,
     &press_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, &press_state->common_attributes);
 return ret;
}

/* Function to deinitialize the processing for usage id */
static void hid_press_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 press_state *press_state = iio_priv(indio_dev);

 sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_PRESSURE);
 iio_device_unregister(indio_dev);
 hid_sensor_remove_trigger(indio_dev, &press_state->common_attributes);
}

static const struct platform_device_id hid_press_ids[] = {
 {
  /* Format: HID-SENSOR-usage_id_in_hex_lowercase */
  .name = "HID-SENSOR-200031",
 },
 { }
};
MODULE_DEVICE_TABLE(platform, hid_press_ids);

static struct platform_driver hid_press_platform_driver = {
 .id_table = hid_press_ids,
 .driver = {
  .name = KBUILD_MODNAME,
  .pm = &hid_sensor_pm_ops,
 },
 .probe  = hid_press_probe,
 .remove  = hid_press_remove,
};
module_platform_driver(hid_press_platform_driver);

MODULE_DESCRIPTION("HID Sensor Pressure");
MODULE_AUTHOR("Archana Patni <archana.patni@intel.com>");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("IIO_HID");