LXR linux/drivers/iio/humidity/hid-sensor-humidity.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * HID Sensors Driver
   4 * Copyright (c) 2017, Intel Corporation.
   5 */
   6#include <linux/device.h>
   7#include <linux/hid-sensor-hub.h>
   8#include <linux/iio/buffer.h>
   9#include <linux/iio/iio.h>
  10#include <linux/module.h>
  11#include <linux/mod_devicetable.h>
  12#include <linux/platform_device.h>
  13
  14#include "hid-sensor-trigger.h"
  15
  16struct hid_humidity_state {
  17        struct hid_sensor_common common_attributes;
  18        struct hid_sensor_hub_attribute_info humidity_attr;
  19        struct {
  20                s32 humidity_data;
  21                u64 timestamp __aligned(8);
  22        } scan;
  23        int scale_pre_decml;
  24        int scale_post_decml;
  25        int scale_precision;
  26        int value_offset;
  27};
  28
  29static const u32 humidity_sensitivity_addresses[] = {
  30        HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
  31};
  32
  33/* Channel definitions */
  34static const struct iio_chan_spec humidity_channels[] = {
  35        {
  36                .type = IIO_HUMIDITYRELATIVE,
  37                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  38                .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
  39                        BIT(IIO_CHAN_INFO_SCALE) |
  40                        BIT(IIO_CHAN_INFO_SAMP_FREQ) |
  41                        BIT(IIO_CHAN_INFO_HYSTERESIS),
  42        },
  43        IIO_CHAN_SOFT_TIMESTAMP(1)
  44};
  45
  46/* Adjust channel real bits based on report descriptor */
  47static void humidity_adjust_channel_bit_mask(struct iio_chan_spec *channels,
  48                                        int channel, int size)
  49{
  50        channels[channel].scan_type.sign = 's';
  51        /* Real storage bits will change based on the report desc. */
  52        channels[channel].scan_type.realbits = size * 8;
  53        /* Maximum size of a sample to capture is s32 */
  54        channels[channel].scan_type.storagebits = sizeof(s32) * 8;
  55}
  56
  57static int humidity_read_raw(struct iio_dev *indio_dev,
  58                                struct iio_chan_spec const *chan,
  59                                int *val, int *val2, long mask)
  60{
  61        struct hid_humidity_state *humid_st = iio_priv(indio_dev);
  62
  63        switch (mask) {
  64        case IIO_CHAN_INFO_RAW:
  65                if (chan->type != IIO_HUMIDITYRELATIVE)
  66                        return -EINVAL;
  67                hid_sensor_power_state(&humid_st->common_attributes, true);
  68                *val = sensor_hub_input_attr_get_raw_value(
  69                                humid_st->common_attributes.hsdev,
  70                                HID_USAGE_SENSOR_HUMIDITY,
  71                                HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
  72                                humid_st->humidity_attr.report_id,
  73                                SENSOR_HUB_SYNC,
  74                                humid_st->humidity_attr.logical_minimum < 0);
  75                hid_sensor_power_state(&humid_st->common_attributes, false);
  76
  77                return IIO_VAL_INT;
  78
  79        case IIO_CHAN_INFO_SCALE:
  80                *val = humid_st->scale_pre_decml;
  81                *val2 = humid_st->scale_post_decml;
  82
  83                return humid_st->scale_precision;
  84
  85        case IIO_CHAN_INFO_OFFSET:
  86                *val = humid_st->value_offset;
  87
  88                return IIO_VAL_INT;
  89
  90        case IIO_CHAN_INFO_SAMP_FREQ:
  91                return hid_sensor_read_samp_freq_value(
  92                                &humid_st->common_attributes, val, val2);
  93
  94        case IIO_CHAN_INFO_HYSTERESIS:
  95                return hid_sensor_read_raw_hyst_value(
  96                                &humid_st->common_attributes, val, val2);
  97
  98        default:
  99                return -EINVAL;
 100        }
 101}
 102
 103static int humidity_write_raw(struct iio_dev *indio_dev,
 104                                struct iio_chan_spec const *chan,
 105                                int val, int val2, long mask)
 106{
 107        struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 108
 109        switch (mask) {
 110        case IIO_CHAN_INFO_SAMP_FREQ:
 111                return hid_sensor_write_samp_freq_value(
 112                                &humid_st->common_attributes, val, val2);
 113
 114        case IIO_CHAN_INFO_HYSTERESIS:
 115                return hid_sensor_write_raw_hyst_value(
 116                                &humid_st->common_attributes, val, val2);
 117
 118        default:
 119                return -EINVAL;
 120        }
 121}
 122
 123static const struct iio_info humidity_info = {
 124        .read_raw = &humidity_read_raw,
 125        .write_raw = &humidity_write_raw,
 126};
 127
 128/* Callback handler to send event after all samples are received and captured */
 129static int humidity_proc_event(struct hid_sensor_hub_device *hsdev,
 130                                unsigned int usage_id, void *pdev)
 131{
 132        struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 133        struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 134
 135        if (atomic_read(&humid_st->common_attributes.data_ready))
 136                iio_push_to_buffers_with_timestamp(indio_dev, &humid_st->scan,
 137                                                   iio_get_time_ns(indio_dev));
 138
 139        return 0;
 140}
 141
 142/* Capture samples in local storage */
 143static int humidity_capture_sample(struct hid_sensor_hub_device *hsdev,
 144                                unsigned int usage_id, size_t raw_len,
 145                                char *raw_data, void *pdev)
 146{
 147        struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 148        struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 149
 150        switch (usage_id) {
 151        case HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY:
 152                humid_st->scan.humidity_data = *(s32 *)raw_data;
 153
 154                return 0;
 155        default:
 156                return -EINVAL;
 157        }
 158}
 159
 160/* Parse report which is specific to an usage id */
 161static int humidity_parse_report(struct platform_device *pdev,
 162                                struct hid_sensor_hub_device *hsdev,
 163                                struct iio_chan_spec *channels,
 164                                unsigned int usage_id,
 165                                struct hid_humidity_state *st)
 166{
 167        int ret;
 168
 169        ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
 170                                        usage_id,
 171                                        HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
 172                                        &st->humidity_attr);
 173        if (ret < 0)
 174                return ret;
 175
 176        humidity_adjust_channel_bit_mask(channels, 0, st->humidity_attr.size);
 177
 178        st->scale_precision = hid_sensor_format_scale(
 179                                                HID_USAGE_SENSOR_HUMIDITY,
 180                                                &st->humidity_attr,
 181                                                &st->scale_pre_decml,
 182                                                &st->scale_post_decml);
 183
 184        return ret;
 185}
 186
 187static struct hid_sensor_hub_callbacks humidity_callbacks = {
 188        .send_event = &humidity_proc_event,
 189        .capture_sample = &humidity_capture_sample,
 190};
 191
 192/* Function to initialize the processing for usage id */
 193static int hid_humidity_probe(struct platform_device *pdev)
 194{
 195        static const char *name = "humidity";
 196        struct iio_dev *indio_dev;
 197        struct hid_humidity_state *humid_st;
 198        struct iio_chan_spec *humid_chans;
 199        struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 200        int ret;
 201
 202        indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*humid_st));
 203        if (!indio_dev)
 204                return -ENOMEM;
 205
 206        humid_st = iio_priv(indio_dev);
 207        humid_st->common_attributes.hsdev = hsdev;
 208        humid_st->common_attributes.pdev = pdev;
 209
 210        ret = hid_sensor_parse_common_attributes(hsdev,
 211                                        HID_USAGE_SENSOR_HUMIDITY,
 212                                        &humid_st->common_attributes,
 213                                        humidity_sensitivity_addresses,
 214                                        ARRAY_SIZE(humidity_sensitivity_addresses));
 215        if (ret)
 216                return ret;
 217
 218        humid_chans = devm_kmemdup(&indio_dev->dev, humidity_channels,
 219                                        sizeof(humidity_channels), GFP_KERNEL);
 220        if (!humid_chans)
 221                return -ENOMEM;
 222
 223        ret = humidity_parse_report(pdev, hsdev, humid_chans,
 224                                HID_USAGE_SENSOR_HUMIDITY, humid_st);
 225        if (ret)
 226                return ret;
 227
 228        indio_dev->channels = humid_chans;
 229        indio_dev->num_channels = ARRAY_SIZE(humidity_channels);
 230        indio_dev->info = &humidity_info;
 231        indio_dev->name = name;
 232        indio_dev->modes = INDIO_DIRECT_MODE;
 233
 234        atomic_set(&humid_st->common_attributes.data_ready, 0);
 235
 236        ret = hid_sensor_setup_trigger(indio_dev, name,
 237                                &humid_st->common_attributes);
 238        if (ret)
 239                return ret;
 240
 241        platform_set_drvdata(pdev, indio_dev);
 242
 243        humidity_callbacks.pdev = pdev;
 244        ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY,
 245                                        &humidity_callbacks);
 246        if (ret)
 247                goto error_remove_trigger;
 248
 249        ret = iio_device_register(indio_dev);
 250        if (ret)
 251                goto error_remove_callback;
 252
 253        return ret;
 254
 255error_remove_callback:
 256        sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY);
 257error_remove_trigger:
 258        hid_sensor_remove_trigger(indio_dev, &humid_st->common_attributes);
 259        return ret;
 260}
 261
 262/* Function to deinitialize the processing for usage id */
 263static int hid_humidity_remove(struct platform_device *pdev)
 264{
 265        struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 266        struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 267        struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 268
 269        iio_device_unregister(indio_dev);
 270        sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY);
 271        hid_sensor_remove_trigger(indio_dev, &humid_st->common_attributes);
 272
 273        return 0;
 274}
 275
 276static const struct platform_device_id hid_humidity_ids[] = {
 277        {
 278                /* Format: HID-SENSOR-usage_id_in_hex_lowercase */
 279                .name = "HID-SENSOR-200032",
 280        },
 281        { /* sentinel */ }
 282};
 283MODULE_DEVICE_TABLE(platform, hid_humidity_ids);
 284
 285static struct platform_driver hid_humidity_platform_driver = {
 286        .id_table = hid_humidity_ids,
 287        .driver = {
 288                .name   = KBUILD_MODNAME,
 289                .pm     = &hid_sensor_pm_ops,
 290        },
 291        .probe          = hid_humidity_probe,
 292        .remove         = hid_humidity_remove,
 293};
 294module_platform_driver(hid_humidity_platform_driver);
 295
 296MODULE_DESCRIPTION("HID Environmental humidity sensor");
 297MODULE_AUTHOR("Song Hongyan <hongyan.song@intel.com>");
 298MODULE_LICENSE("GPL v2");
 299MODULE_IMPORT_NS(IIO_HID);
 300