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