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

   1/*
   2 * HID Sensors Driver
   3 * Copyright (c) 2017, Intel Corporation.
   4 *
   5 * This program is free software; you can redistribute it and/or modify it
   6 * under the terms and conditions of the GNU General Public License,
   7 * version 2, as published by the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope it will be useful, but WITHOUT
  10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12 * more details.
  13 *
  14 * You should have received a copy of the GNU General Public License along with
  15 * this program.
  16 */
  17#include <linux/device.h>
  18#include <linux/hid-sensor-hub.h>
  19#include <linux/iio/buffer.h>
  20#include <linux/iio/iio.h>
  21#include <linux/iio/triggered_buffer.h>
  22#include <linux/iio/trigger_consumer.h>
  23#include <linux/module.h>
  24#include <linux/platform_device.h>
  25
  26#include "hid-sensor-trigger.h"
  27
  28struct hid_humidity_state {
  29        struct hid_sensor_common common_attributes;
  30        struct hid_sensor_hub_attribute_info humidity_attr;
  31        s32 humidity_data;
  32        int scale_pre_decml;
  33        int scale_post_decml;
  34        int scale_precision;
  35        int value_offset;
  36};
  37
  38/* Channel definitions */
  39static const struct iio_chan_spec humidity_channels[] = {
  40        {
  41                .type = IIO_HUMIDITYRELATIVE,
  42                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  43                .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
  44                        BIT(IIO_CHAN_INFO_SCALE) |
  45                        BIT(IIO_CHAN_INFO_SAMP_FREQ) |
  46                        BIT(IIO_CHAN_INFO_HYSTERESIS),
  47        },
  48        IIO_CHAN_SOFT_TIMESTAMP(1)
  49};
  50
  51/* Adjust channel real bits based on report descriptor */
  52static void humidity_adjust_channel_bit_mask(struct iio_chan_spec *channels,
  53                                        int channel, int size)
  54{
  55        channels[channel].scan_type.sign = 's';
  56        /* Real storage bits will change based on the report desc. */
  57        channels[channel].scan_type.realbits = size * 8;
  58        /* Maximum size of a sample to capture is s32 */
  59        channels[channel].scan_type.storagebits = sizeof(s32) * 8;
  60}
  61
  62static int humidity_read_raw(struct iio_dev *indio_dev,
  63                                struct iio_chan_spec const *chan,
  64                                int *val, int *val2, long mask)
  65{
  66        struct hid_humidity_state *humid_st = iio_priv(indio_dev);
  67
  68        switch (mask) {
  69        case IIO_CHAN_INFO_RAW:
  70                if (chan->type != IIO_HUMIDITYRELATIVE)
  71                        return -EINVAL;
  72                hid_sensor_power_state(&humid_st->common_attributes, true);
  73                *val = sensor_hub_input_attr_get_raw_value(
  74                                humid_st->common_attributes.hsdev,
  75                                HID_USAGE_SENSOR_HUMIDITY,
  76                                HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
  77                                humid_st->humidity_attr.report_id,
  78                                SENSOR_HUB_SYNC);
  79                hid_sensor_power_state(&humid_st->common_attributes, false);
  80
  81                return IIO_VAL_INT;
  82
  83        case IIO_CHAN_INFO_SCALE:
  84                *val = humid_st->scale_pre_decml;
  85                *val2 = humid_st->scale_post_decml;
  86
  87                return humid_st->scale_precision;
  88
  89        case IIO_CHAN_INFO_OFFSET:
  90                *val = humid_st->value_offset;
  91
  92                return IIO_VAL_INT;
  93
  94        case IIO_CHAN_INFO_SAMP_FREQ:
  95                return hid_sensor_read_samp_freq_value(
  96                                &humid_st->common_attributes, val, val2);
  97
  98        case IIO_CHAN_INFO_HYSTERESIS:
  99                return hid_sensor_read_raw_hyst_value(
 100                                &humid_st->common_attributes, val, val2);
 101
 102        default:
 103                return -EINVAL;
 104        }
 105}
 106
 107static int humidity_write_raw(struct iio_dev *indio_dev,
 108                                struct iio_chan_spec const *chan,
 109                                int val, int val2, long mask)
 110{
 111        struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 112
 113        switch (mask) {
 114        case IIO_CHAN_INFO_SAMP_FREQ:
 115                return hid_sensor_write_samp_freq_value(
 116                                &humid_st->common_attributes, val, val2);
 117
 118        case IIO_CHAN_INFO_HYSTERESIS:
 119                return hid_sensor_write_raw_hyst_value(
 120                                &humid_st->common_attributes, val, val2);
 121
 122        default:
 123                return -EINVAL;
 124        }
 125}
 126
 127static const struct iio_info humidity_info = {
 128        .driver_module = THIS_MODULE,
 129        .read_raw = &humidity_read_raw,
 130        .write_raw = &humidity_write_raw,
 131};
 132
 133/* Callback handler to send event after all samples are received and captured */
 134static int humidity_proc_event(struct hid_sensor_hub_device *hsdev,
 135                                unsigned int usage_id, void *pdev)
 136{
 137        struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 138        struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 139
 140        if (atomic_read(&humid_st->common_attributes.data_ready))
 141                iio_push_to_buffers_with_timestamp(indio_dev,
 142                                        &humid_st->humidity_data,
 143                                        iio_get_time_ns(indio_dev));
 144
 145        return 0;
 146}
 147
 148/* Capture samples in local storage */
 149static int humidity_capture_sample(struct hid_sensor_hub_device *hsdev,
 150                                unsigned int usage_id, size_t raw_len,
 151                                char *raw_data, void *pdev)
 152{
 153        struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 154        struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 155
 156        switch (usage_id) {
 157        case HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY:
 158                humid_st->humidity_data = *(s32 *)raw_data;
 159
 160                return 0;
 161        default:
 162                return -EINVAL;
 163        }
 164}
 165
 166/* Parse report which is specific to an usage id */
 167static int humidity_parse_report(struct platform_device *pdev,
 168                                struct hid_sensor_hub_device *hsdev,
 169                                struct iio_chan_spec *channels,
 170                                unsigned int usage_id,
 171                                struct hid_humidity_state *st)
 172{
 173        int ret;
 174
 175        ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
 176                                        usage_id,
 177                                        HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
 178                                        &st->humidity_attr);
 179        if (ret < 0)
 180                return ret;
 181
 182        humidity_adjust_channel_bit_mask(channels, 0, st->humidity_attr.size);
 183
 184        st->scale_precision = hid_sensor_format_scale(
 185                                                HID_USAGE_SENSOR_HUMIDITY,
 186                                                &st->humidity_attr,
 187                                                &st->scale_pre_decml,
 188                                                &st->scale_post_decml);
 189
 190        /* Set Sensitivity field ids, when there is no individual modifier */
 191        if (st->common_attributes.sensitivity.index < 0)
 192                sensor_hub_input_get_attribute_info(hsdev,
 193                        HID_FEATURE_REPORT, usage_id,
 194                        HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
 195                        HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
 196                        &st->common_attributes.sensitivity);
 197
 198        return ret;
 199}
 200
 201static struct hid_sensor_hub_callbacks humidity_callbacks = {
 202        .send_event = &humidity_proc_event,
 203        .capture_sample = &humidity_capture_sample,
 204};
 205
 206/* Function to initialize the processing for usage id */
 207static int hid_humidity_probe(struct platform_device *pdev)
 208{
 209        static const char *name = "humidity";
 210        struct iio_dev *indio_dev;
 211        struct hid_humidity_state *humid_st;
 212        struct iio_chan_spec *humid_chans;
 213        struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 214        int ret;
 215
 216        indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*humid_st));
 217        if (!indio_dev)
 218                return -ENOMEM;
 219
 220        humid_st = iio_priv(indio_dev);
 221        humid_st->common_attributes.hsdev = hsdev;
 222        humid_st->common_attributes.pdev = pdev;
 223
 224        ret = hid_sensor_parse_common_attributes(hsdev,
 225                                        HID_USAGE_SENSOR_HUMIDITY,
 226                                        &humid_st->common_attributes);
 227        if (ret)
 228                return ret;
 229
 230        humid_chans = devm_kmemdup(&indio_dev->dev, humidity_channels,
 231                                        sizeof(humidity_channels), GFP_KERNEL);
 232        if (!humid_chans)
 233                return -ENOMEM;
 234
 235        ret = humidity_parse_report(pdev, hsdev, humid_chans,
 236                                HID_USAGE_SENSOR_HUMIDITY, humid_st);
 237        if (ret)
 238                return ret;
 239
 240        indio_dev->channels = humid_chans;
 241        indio_dev->num_channels = ARRAY_SIZE(humidity_channels);
 242        indio_dev->dev.parent = &pdev->dev;
 243        indio_dev->info = &humidity_info;
 244        indio_dev->name = name;
 245        indio_dev->modes = INDIO_DIRECT_MODE;
 246
 247        ret = devm_iio_triggered_buffer_setup(&pdev->dev, indio_dev,
 248                                        &iio_pollfunc_store_time, NULL, NULL);
 249        if (ret)
 250                return ret;
 251
 252        atomic_set(&humid_st->common_attributes.data_ready, 0);
 253        ret = hid_sensor_setup_trigger(indio_dev, name,
 254                                &humid_st->common_attributes);
 255        if (ret)
 256                return ret;
 257
 258        platform_set_drvdata(pdev, indio_dev);
 259
 260        humidity_callbacks.pdev = pdev;
 261        ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY,
 262                                        &humidity_callbacks);
 263        if (ret)
 264                goto error_remove_trigger;
 265
 266        ret = iio_device_register(indio_dev);
 267        if (ret)
 268                goto error_remove_callback;
 269
 270        return ret;
 271
 272error_remove_callback:
 273        sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY);
 274error_remove_trigger:
 275        hid_sensor_remove_trigger(&humid_st->common_attributes);
 276        return ret;
 277}
 278
 279/* Function to deinitialize the processing for usage id */
 280static int hid_humidity_remove(struct platform_device *pdev)
 281{
 282        struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 283        struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 284        struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 285
 286        iio_device_unregister(indio_dev);
 287        sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY);
 288        hid_sensor_remove_trigger(&humid_st->common_attributes);
 289
 290        return 0;
 291}
 292
 293static const struct platform_device_id hid_humidity_ids[] = {
 294        {
 295                /* Format: HID-SENSOR-usage_id_in_hex_lowercase */
 296                .name = "HID-SENSOR-200032",
 297        },
 298        { /* sentinel */ }
 299};
 300MODULE_DEVICE_TABLE(platform, hid_humidity_ids);
 301
 302static struct platform_driver hid_humidity_platform_driver = {
 303        .id_table = hid_humidity_ids,
 304        .driver = {
 305                .name   = KBUILD_MODNAME,
 306                .pm     = &hid_sensor_pm_ops,
 307        },
 308        .probe          = hid_humidity_probe,
 309        .remove         = hid_humidity_remove,
 310};
 311module_platform_driver(hid_humidity_platform_driver);
 312
 313MODULE_DESCRIPTION("HID Environmental humidity sensor");
 314MODULE_AUTHOR("Song Hongyan <hongyan.song@intel.com>");
 315MODULE_LICENSE("GPL v2");
 316