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
  28 struct hid_humidity_state {
  29         struct hid_sensor_common common_attributes;
  30         struct hid_sensor_hub_attribute_info humidity_attr;
  31         struct {
  32                 s32 humidity_data;
  33                 u64 timestamp __aligned(8);
  34         } scan;
  35         int scale_pre_decml;
  36         int scale_post_decml;
  37         int scale_precision;
  38         int value_offset;
  39 };
  40
  41 /* Channel definitions */
  42 static const struct iio_chan_spec humidity_channels[] = {
  43         {
  44                 .type = IIO_HUMIDITYRELATIVE,
  45                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  46                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
  47                         BIT(IIO_CHAN_INFO_SCALE) |
  48                         BIT(IIO_CHAN_INFO_SAMP_FREQ) |
  49                         BIT(IIO_CHAN_INFO_HYSTERESIS),
  50         },
  51         IIO_CHAN_SOFT_TIMESTAMP(1)
  52 };
  53
  54 /* Adjust channel real bits based on report descriptor */
  55 static void humidity_adjust_channel_bit_mask(struct iio_chan_spec *channels,
  56                                         int channel, int size)
  57 {
  58         channels[channel].scan_type.sign = 's';
  59         /* Real storage bits will change based on the report desc. */
  60         channels[channel].scan_type.realbits = size * 8;
  61         /* Maximum size of a sample to capture is s32 */
  62         channels[channel].scan_type.storagebits = sizeof(s32) * 8;
  63 }
  64
  65 static int humidity_read_raw(struct iio_dev *indio_dev,
  66                                 struct iio_chan_spec const *chan,
  67                                 int *val, int *val2, long mask)
  68 {
  69         struct hid_humidity_state *humid_st = iio_priv(indio_dev);
  70
  71         switch (mask) {
  72         case IIO_CHAN_INFO_RAW:
  73                 if (chan->type != IIO_HUMIDITYRELATIVE)
  74                         return -EINVAL;
  75                 hid_sensor_power_state(&humid_st->common_attributes, true);
  76                 *val = sensor_hub_input_attr_get_raw_value(
  77                                 humid_st->common_attributes.hsdev,
  78                                 HID_USAGE_SENSOR_HUMIDITY,
  79                                 HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
  80                                 humid_st->humidity_attr.report_id,
  81                                 SENSOR_HUB_SYNC,
  82                                 humid_st->humidity_attr.logical_minimum < 0);
  83                 hid_sensor_power_state(&humid_st->common_attributes, false);
  84
  85                 return IIO_VAL_INT;
  86
  87         case IIO_CHAN_INFO_SCALE:
  88                 *val = humid_st->scale_pre_decml;
  89                 *val2 = humid_st->scale_post_decml;
  90
  91                 return humid_st->scale_precision;
  92
  93         case IIO_CHAN_INFO_OFFSET:
  94                 *val = humid_st->value_offset;
  95
  96                 return IIO_VAL_INT;
  97
  98         case IIO_CHAN_INFO_SAMP_FREQ:
  99                 return hid_sensor_read_samp_freq_value(
 100                                 &humid_st->common_attributes, val, val2);
 101
 102         case IIO_CHAN_INFO_HYSTERESIS:
 103                 return hid_sensor_read_raw_hyst_value(
 104                                 &humid_st->common_attributes, val, val2);
 105
 106         default:
 107                 return -EINVAL;
 108         }
 109 }
 110
 111 static int humidity_write_raw(struct iio_dev *indio_dev,
 112                                 struct iio_chan_spec const *chan,
 113                                 int val, int val2, long mask)
 114 {
 115         struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 116
 117         switch (mask) {
 118         case IIO_CHAN_INFO_SAMP_FREQ:
 119                 return hid_sensor_write_samp_freq_value(
 120                                 &humid_st->common_attributes, val, val2);
 121
 122         case IIO_CHAN_INFO_HYSTERESIS:
 123                 return hid_sensor_write_raw_hyst_value(
 124                                 &humid_st->common_attributes, val, val2);
 125
 126         default:
 127                 return -EINVAL;
 128         }
 129 }
 130
 131 static const struct iio_info humidity_info = {
 132         .read_raw = &humidity_read_raw,
 133         .write_raw = &humidity_write_raw,
 134 };
 135
 136 /* Callback handler to send event after all samples are received and captured */
 137 static int humidity_proc_event(struct hid_sensor_hub_device *hsdev,
 138                                 unsigned int usage_id, void *pdev)
 139 {
 140         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 141         struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 142
 143         if (atomic_read(&humid_st->common_attributes.data_ready))
 144                 iio_push_to_buffers_with_timestamp(indio_dev, &humid_st->scan,
 145                                                    iio_get_time_ns(indio_dev));
 146
 147         return 0;
 148 }
 149
 150 /* Capture samples in local storage */
 151 static int humidity_capture_sample(struct hid_sensor_hub_device *hsdev,
 152                                 unsigned int usage_id, size_t raw_len,
 153                                 char *raw_data, void *pdev)
 154 {
 155         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 156         struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 157
 158         switch (usage_id) {
 159         case HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY:
 160                 humid_st->scan.humidity_data = *(s32 *)raw_data;
 161
 162                 return 0;
 163         default:
 164                 return -EINVAL;
 165         }
 166 }
 167
 168 /* Parse report which is specific to an usage id */
 169 static int humidity_parse_report(struct platform_device *pdev,
 170                                 struct hid_sensor_hub_device *hsdev,
 171                                 struct iio_chan_spec *channels,
 172                                 unsigned int usage_id,
 173                                 struct hid_humidity_state *st)
 174 {
 175         int ret;
 176
 177         ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
 178                                         usage_id,
 179                                         HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
 180                                         &st->humidity_attr);
 181         if (ret < 0)
 182                 return ret;
 183
 184         humidity_adjust_channel_bit_mask(channels, 0, st->humidity_attr.size);
 185
 186         st->scale_precision = hid_sensor_format_scale(
 187                                                 HID_USAGE_SENSOR_HUMIDITY,
 188                                                 &st->humidity_attr,
 189                                                 &st->scale_pre_decml,
 190                                                 &st->scale_post_decml);
 191
 192         /* Set Sensitivity field ids, when there is no individual modifier */
 193         if (st->common_attributes.sensitivity.index < 0)
 194                 sensor_hub_input_get_attribute_info(hsdev,
 195                         HID_FEATURE_REPORT, usage_id,
 196                         HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
 197                         HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
 198                         &st->common_attributes.sensitivity);
 199
 200         return ret;
 201 }
 202
 203 static struct hid_sensor_hub_callbacks humidity_callbacks = {
 204         .send_event = &humidity_proc_event,
 205         .capture_sample = &humidity_capture_sample,
 206 };
 207
 208 /* Function to initialize the processing for usage id */
 209 static int hid_humidity_probe(struct platform_device *pdev)
 210 {
 211         static const char *name = "humidity";
 212         struct iio_dev *indio_dev;
 213         struct hid_humidity_state *humid_st;
 214         struct iio_chan_spec *humid_chans;
 215         struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 216         int ret;
 217
 218         indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*humid_st));
 219         if (!indio_dev)
 220                 return -ENOMEM;
 221
 222         humid_st = iio_priv(indio_dev);
 223         humid_st->common_attributes.hsdev = hsdev;
 224         humid_st->common_attributes.pdev = pdev;
 225
 226         ret = hid_sensor_parse_common_attributes(hsdev,
 227                                         HID_USAGE_SENSOR_HUMIDITY,
 228                                         &humid_st->common_attributes);
 229         if (ret)
 230                 return ret;
 231
 232         humid_chans = devm_kmemdup(&indio_dev->dev, humidity_channels,
 233                                         sizeof(humidity_channels), GFP_KERNEL);
 234         if (!humid_chans)
 235                 return -ENOMEM;
 236
 237         ret = humidity_parse_report(pdev, hsdev, humid_chans,
 238                                 HID_USAGE_SENSOR_HUMIDITY, humid_st);
 239         if (ret)
 240                 return ret;
 241
 242         indio_dev->channels = humid_chans;
 243         indio_dev->num_channels = ARRAY_SIZE(humidity_channels);
 244         indio_dev->dev.parent = &pdev->dev;
 245         indio_dev->info = &humidity_info;
 246         indio_dev->name = name;
 247         indio_dev->modes = INDIO_DIRECT_MODE;
 248
 249         ret = devm_iio_triggered_buffer_setup(&pdev->dev, indio_dev,
 250                                         &iio_pollfunc_store_time, NULL, NULL);
 251         if (ret)
 252                 return ret;
 253
 254         atomic_set(&humid_st->common_attributes.data_ready, 0);
 255         ret = hid_sensor_setup_trigger(indio_dev, name,
 256                                 &humid_st->common_attributes);
 257         if (ret)
 258                 return ret;
 259
 260         platform_set_drvdata(pdev, indio_dev);
 261
 262         humidity_callbacks.pdev = pdev;
 263         ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY,
 264                                         &humidity_callbacks);
 265         if (ret)
 266                 goto error_remove_trigger;
 267
 268         ret = iio_device_register(indio_dev);
 269         if (ret)
 270                 goto error_remove_callback;
 271
 272         return ret;
 273
 274 error_remove_callback:
 275         sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY);
 276 error_remove_trigger:
 277         hid_sensor_remove_trigger(&humid_st->common_attributes);
 278         return ret;
 279 }
 280
 281 /* Function to deinitialize the processing for usage id */
 282 static int hid_humidity_remove(struct platform_device *pdev)
 283 {
 284         struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 285         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 286         struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 287
 288         iio_device_unregister(indio_dev);
 289         sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY);
 290         hid_sensor_remove_trigger(&humid_st->common_attributes);
 291
 292         return 0;
 293 }
 294
 295 static const struct platform_device_id hid_humidity_ids[] = {
 296         {
 297                 /* Format: HID-SENSOR-usage_id_in_hex_lowercase */
 298                 .name = "HID-SENSOR-200032",
 299         },
 300         { /* sentinel */ }
 301 };
 302 MODULE_DEVICE_TABLE(platform, hid_humidity_ids);
 303
 304 static struct platform_driver hid_humidity_platform_driver = {
 305         .id_table = hid_humidity_ids,
 306         .driver = {
 307                 .name   = KBUILD_MODNAME,
 308                 .pm     = &hid_sensor_pm_ops,
 309         },
 310         .probe          = hid_humidity_probe,
 311         .remove         = hid_humidity_remove,
 312 };
 313 module_platform_driver(hid_humidity_platform_driver);
 314
 315 MODULE_DESCRIPTION("HID Environmental humidity sensor");
 316 MODULE_AUTHOR("Song Hongyan <hongyan.song@intel.com>");
 317 MODULE_LICENSE("GPL v2");