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