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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * HID Sensors Driver
   4  * Copyright (c) 2017, Intel Corporation.
   5  */
   6 #include <linux/device.h>
   7 #include <linux/hid-sensor-hub.h>
   8 #include <linux/iio/buffer.h>
   9 #include <linux/iio/iio.h>
  10 #include <linux/module.h>
  11 #include <linux/platform_device.h>
  12
  13 #include "hid-sensor-trigger.h"
  14
  15 struct hid_humidity_state {
  16         struct hid_sensor_common common_attributes;
  17         struct hid_sensor_hub_attribute_info humidity_attr;
  18         struct {
  19                 s32 humidity_data;
  20                 u64 timestamp __aligned(8);
  21         } scan;
  22         int scale_pre_decml;
  23         int scale_post_decml;
  24         int scale_precision;
  25         int value_offset;
  26 };
  27
  28 static const u32 humidity_sensitivity_addresses[] = {
  29         HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
  30 };
  31
  32 /* Channel definitions */
  33 static const struct iio_chan_spec humidity_channels[] = {
  34         {
  35                 .type = IIO_HUMIDITYRELATIVE,
  36                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  37                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
  38                         BIT(IIO_CHAN_INFO_SCALE) |
  39                         BIT(IIO_CHAN_INFO_SAMP_FREQ) |
  40                         BIT(IIO_CHAN_INFO_HYSTERESIS),
  41         },
  42         IIO_CHAN_SOFT_TIMESTAMP(1)
  43 };
  44
  45 /* Adjust channel real bits based on report descriptor */
  46 static void humidity_adjust_channel_bit_mask(struct iio_chan_spec *channels,
  47                                         int channel, int size)
  48 {
  49         channels[channel].scan_type.sign = 's';
  50         /* Real storage bits will change based on the report desc. */
  51         channels[channel].scan_type.realbits = size * 8;
  52         /* Maximum size of a sample to capture is s32 */
  53         channels[channel].scan_type.storagebits = sizeof(s32) * 8;
  54 }
  55
  56 static int humidity_read_raw(struct iio_dev *indio_dev,
  57                                 struct iio_chan_spec const *chan,
  58                                 int *val, int *val2, long mask)
  59 {
  60         struct hid_humidity_state *humid_st = iio_priv(indio_dev);
  61
  62         switch (mask) {
  63         case IIO_CHAN_INFO_RAW:
  64                 if (chan->type != IIO_HUMIDITYRELATIVE)
  65                         return -EINVAL;
  66                 hid_sensor_power_state(&humid_st->common_attributes, true);
  67                 *val = sensor_hub_input_attr_get_raw_value(
  68                                 humid_st->common_attributes.hsdev,
  69                                 HID_USAGE_SENSOR_HUMIDITY,
  70                                 HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
  71                                 humid_st->humidity_attr.report_id,
  72                                 SENSOR_HUB_SYNC,
  73                                 humid_st->humidity_attr.logical_minimum < 0);
  74                 hid_sensor_power_state(&humid_st->common_attributes, false);
  75
  76                 return IIO_VAL_INT;
  77
  78         case IIO_CHAN_INFO_SCALE:
  79                 *val = humid_st->scale_pre_decml;
  80                 *val2 = humid_st->scale_post_decml;
  81
  82                 return humid_st->scale_precision;
  83
  84         case IIO_CHAN_INFO_OFFSET:
  85                 *val = humid_st->value_offset;
  86
  87                 return IIO_VAL_INT;
  88
  89         case IIO_CHAN_INFO_SAMP_FREQ:
  90                 return hid_sensor_read_samp_freq_value(
  91                                 &humid_st->common_attributes, val, val2);
  92
  93         case IIO_CHAN_INFO_HYSTERESIS:
  94                 return hid_sensor_read_raw_hyst_value(
  95                                 &humid_st->common_attributes, val, val2);
  96
  97         default:
  98                 return -EINVAL;
  99         }
 100 }
 101
 102 static int humidity_write_raw(struct iio_dev *indio_dev,
 103                                 struct iio_chan_spec const *chan,
 104                                 int val, int val2, long mask)
 105 {
 106         struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 107
 108         switch (mask) {
 109         case IIO_CHAN_INFO_SAMP_FREQ:
 110                 return hid_sensor_write_samp_freq_value(
 111                                 &humid_st->common_attributes, val, val2);
 112
 113         case IIO_CHAN_INFO_HYSTERESIS:
 114                 return hid_sensor_write_raw_hyst_value(
 115                                 &humid_st->common_attributes, val, val2);
 116
 117         default:
 118                 return -EINVAL;
 119         }
 120 }
 121
 122 static const struct iio_info humidity_info = {
 123         .read_raw = &humidity_read_raw,
 124         .write_raw = &humidity_write_raw,
 125 };
 126
 127 /* Callback handler to send event after all samples are received and captured */
 128 static int humidity_proc_event(struct hid_sensor_hub_device *hsdev,
 129                                 unsigned int usage_id, void *pdev)
 130 {
 131         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 132         struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 133
 134         if (atomic_read(&humid_st->common_attributes.data_ready))
 135                 iio_push_to_buffers_with_timestamp(indio_dev, &humid_st->scan,
 136                                                    iio_get_time_ns(indio_dev));
 137
 138         return 0;
 139 }
 140
 141 /* Capture samples in local storage */
 142 static int humidity_capture_sample(struct hid_sensor_hub_device *hsdev,
 143                                 unsigned int usage_id, size_t raw_len,
 144                                 char *raw_data, void *pdev)
 145 {
 146         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 147         struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 148
 149         switch (usage_id) {
 150         case HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY:
 151                 humid_st->scan.humidity_data = *(s32 *)raw_data;
 152
 153                 return 0;
 154         default:
 155                 return -EINVAL;
 156         }
 157 }
 158
 159 /* Parse report which is specific to an usage id */
 160 static int humidity_parse_report(struct platform_device *pdev,
 161                                 struct hid_sensor_hub_device *hsdev,
 162                                 struct iio_chan_spec *channels,
 163                                 unsigned int usage_id,
 164                                 struct hid_humidity_state *st)
 165 {
 166         int ret;
 167
 168         ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
 169                                         usage_id,
 170                                         HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
 171                                         &st->humidity_attr);
 172         if (ret < 0)
 173                 return ret;
 174
 175         humidity_adjust_channel_bit_mask(channels, 0, st->humidity_attr.size);
 176
 177         st->scale_precision = hid_sensor_format_scale(
 178                                                 HID_USAGE_SENSOR_HUMIDITY,
 179                                                 &st->humidity_attr,
 180                                                 &st->scale_pre_decml,
 181                                                 &st->scale_post_decml);
 182
 183         return ret;
 184 }
 185
 186 static struct hid_sensor_hub_callbacks humidity_callbacks = {
 187         .send_event = &humidity_proc_event,
 188         .capture_sample = &humidity_capture_sample,
 189 };
 190
 191 /* Function to initialize the processing for usage id */
 192 static int hid_humidity_probe(struct platform_device *pdev)
 193 {
 194         static const char *name = "humidity";
 195         struct iio_dev *indio_dev;
 196         struct hid_humidity_state *humid_st;
 197         struct iio_chan_spec *humid_chans;
 198         struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 199         int ret;
 200
 201         indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*humid_st));
 202         if (!indio_dev)
 203                 return -ENOMEM;
 204
 205         humid_st = iio_priv(indio_dev);
 206         humid_st->common_attributes.hsdev = hsdev;
 207         humid_st->common_attributes.pdev = pdev;
 208
 209         ret = hid_sensor_parse_common_attributes(hsdev,
 210                                         HID_USAGE_SENSOR_HUMIDITY,
 211                                         &humid_st->common_attributes,
 212                                         humidity_sensitivity_addresses,
 213                                         ARRAY_SIZE(humidity_sensitivity_addresses));
 214         if (ret)
 215                 return ret;
 216
 217         humid_chans = devm_kmemdup(&indio_dev->dev, humidity_channels,
 218                                         sizeof(humidity_channels), GFP_KERNEL);
 219         if (!humid_chans)
 220                 return -ENOMEM;
 221
 222         ret = humidity_parse_report(pdev, hsdev, humid_chans,
 223                                 HID_USAGE_SENSOR_HUMIDITY, humid_st);
 224         if (ret)
 225                 return ret;
 226
 227         indio_dev->channels = humid_chans;
 228         indio_dev->num_channels = ARRAY_SIZE(humidity_channels);
 229         indio_dev->info = &humidity_info;
 230         indio_dev->name = name;
 231         indio_dev->modes = INDIO_DIRECT_MODE;
 232
 233         atomic_set(&humid_st->common_attributes.data_ready, 0);
 234
 235         ret = hid_sensor_setup_trigger(indio_dev, name,
 236                                 &humid_st->common_attributes);
 237         if (ret)
 238                 return ret;
 239
 240         platform_set_drvdata(pdev, indio_dev);
 241
 242         humidity_callbacks.pdev = pdev;
 243         ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY,
 244                                         &humidity_callbacks);
 245         if (ret)
 246                 goto error_remove_trigger;
 247
 248         ret = iio_device_register(indio_dev);
 249         if (ret)
 250                 goto error_remove_callback;
 251
 252         return ret;
 253
 254 error_remove_callback:
 255         sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY);
 256 error_remove_trigger:
 257         hid_sensor_remove_trigger(indio_dev, &humid_st->common_attributes);
 258         return ret;
 259 }
 260
 261 /* Function to deinitialize the processing for usage id */
 262 static int hid_humidity_remove(struct platform_device *pdev)
 263 {
 264         struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 265         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 266         struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 267
 268         iio_device_unregister(indio_dev);
 269         sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY);
 270         hid_sensor_remove_trigger(indio_dev, &humid_st->common_attributes);
 271
 272         return 0;
 273 }
 274
 275 static const struct platform_device_id hid_humidity_ids[] = {
 276         {
 277                 /* Format: HID-SENSOR-usage_id_in_hex_lowercase */
 278                 .name = "HID-SENSOR-200032",
 279         },
 280         { /* sentinel */ }
 281 };
 282 MODULE_DEVICE_TABLE(platform, hid_humidity_ids);
 283
 284 static struct platform_driver hid_humidity_platform_driver = {
 285         .id_table = hid_humidity_ids,
 286         .driver = {
 287                 .name   = KBUILD_MODNAME,
 288                 .pm     = &hid_sensor_pm_ops,
 289         },
 290         .probe          = hid_humidity_probe,
 291         .remove         = hid_humidity_remove,
 292 };
 293 module_platform_driver(hid_humidity_platform_driver);
 294
 295 MODULE_DESCRIPTION("HID Environmental humidity sensor");
 296 MODULE_AUTHOR("Song Hongyan <hongyan.song@intel.com>");
 297 MODULE_LICENSE("GPL v2");