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         .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 */
 134 static 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 */
 149 static 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 */
 167 static 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
 201 static 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 */
 207 static 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
 272 error_remove_callback:
 273         sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY);
 274 error_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 */
 280 static 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
 293 static 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 };
 300 MODULE_DEVICE_TABLE(platform, hid_humidity_ids);
 301
 302 static 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 };
 311 module_platform_driver(hid_humidity_platform_driver);
 312
 313 MODULE_DESCRIPTION("HID Environmental humidity sensor");
 314 MODULE_AUTHOR("Song Hongyan <hongyan.song@intel.com>");
 315 MODULE_LICENSE("GPL v2");