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/mod_devicetable.h>
  12 #include <linux/platform_device.h>
  13
  14 #include "hid-sensor-trigger.h"
  15
  16 struct hid_humidity_state {
  17         struct hid_sensor_common common_attributes;
  18         struct hid_sensor_hub_attribute_info humidity_attr;
  19         struct {
  20                 s32 humidity_data;
  21                 aligned_s64 timestamp;
  22         } scan;
  23         int scale_pre_decml;
  24         int scale_post_decml;
  25         int scale_precision;
  26         int value_offset;
  27 };
  28
  29 static const u32 humidity_sensitivity_addresses[] = {
  30         HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
  31 };
  32
  33 /* Channel definitions */
  34 static const struct iio_chan_spec humidity_channels[] = {
  35         {
  36                 .type = IIO_HUMIDITYRELATIVE,
  37                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  38                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
  39                         BIT(IIO_CHAN_INFO_SCALE) |
  40                         BIT(IIO_CHAN_INFO_SAMP_FREQ) |
  41                         BIT(IIO_CHAN_INFO_HYSTERESIS),
  42         },
  43         IIO_CHAN_SOFT_TIMESTAMP(1)
  44 };
  45
  46 /* Adjust channel real bits based on report descriptor */
  47 static void humidity_adjust_channel_bit_mask(struct iio_chan_spec *channels,
  48                                         int channel, int size)
  49 {
  50         channels[channel].scan_type.sign = 's';
  51         /* Real storage bits will change based on the report desc. */
  52         channels[channel].scan_type.realbits = size * 8;
  53         /* Maximum size of a sample to capture is s32 */
  54         channels[channel].scan_type.storagebits = sizeof(s32) * 8;
  55 }
  56
  57 static int humidity_read_raw(struct iio_dev *indio_dev,
  58                                 struct iio_chan_spec const *chan,
  59                                 int *val, int *val2, long mask)
  60 {
  61         struct hid_humidity_state *humid_st = iio_priv(indio_dev);
  62
  63         switch (mask) {
  64         case IIO_CHAN_INFO_RAW:
  65                 if (chan->type != IIO_HUMIDITYRELATIVE)
  66                         return -EINVAL;
  67                 hid_sensor_power_state(&humid_st->common_attributes, true);
  68                 *val = sensor_hub_input_attr_get_raw_value(
  69                                 humid_st->common_attributes.hsdev,
  70                                 HID_USAGE_SENSOR_HUMIDITY,
  71                                 HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
  72                                 humid_st->humidity_attr.report_id,
  73                                 SENSOR_HUB_SYNC,
  74                                 humid_st->humidity_attr.logical_minimum < 0);
  75                 hid_sensor_power_state(&humid_st->common_attributes, false);
  76
  77                 return IIO_VAL_INT;
  78
  79         case IIO_CHAN_INFO_SCALE:
  80                 *val = humid_st->scale_pre_decml;
  81                 *val2 = humid_st->scale_post_decml;
  82
  83                 return humid_st->scale_precision;
  84
  85         case IIO_CHAN_INFO_OFFSET:
  86                 *val = humid_st->value_offset;
  87
  88                 return IIO_VAL_INT;
  89
  90         case IIO_CHAN_INFO_SAMP_FREQ:
  91                 return hid_sensor_read_samp_freq_value(
  92                                 &humid_st->common_attributes, val, val2);
  93
  94         case IIO_CHAN_INFO_HYSTERESIS:
  95                 return hid_sensor_read_raw_hyst_value(
  96                                 &humid_st->common_attributes, val, val2);
  97
  98         default:
  99                 return -EINVAL;
 100         }
 101 }
 102
 103 static int humidity_write_raw(struct iio_dev *indio_dev,
 104                                 struct iio_chan_spec const *chan,
 105                                 int val, int val2, long mask)
 106 {
 107         struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 108
 109         switch (mask) {
 110         case IIO_CHAN_INFO_SAMP_FREQ:
 111                 return hid_sensor_write_samp_freq_value(
 112                                 &humid_st->common_attributes, val, val2);
 113
 114         case IIO_CHAN_INFO_HYSTERESIS:
 115                 return hid_sensor_write_raw_hyst_value(
 116                                 &humid_st->common_attributes, val, val2);
 117
 118         default:
 119                 return -EINVAL;
 120         }
 121 }
 122
 123 static const struct iio_info humidity_info = {
 124         .read_raw = &humidity_read_raw,
 125         .write_raw = &humidity_write_raw,
 126 };
 127
 128 /* Callback handler to send event after all samples are received and captured */
 129 static int humidity_proc_event(struct hid_sensor_hub_device *hsdev,
 130                                 unsigned int usage_id, void *pdev)
 131 {
 132         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 133         struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 134
 135         if (atomic_read(&humid_st->common_attributes.data_ready))
 136                 iio_push_to_buffers_with_timestamp(indio_dev, &humid_st->scan,
 137                                                    iio_get_time_ns(indio_dev));
 138
 139         return 0;
 140 }
 141
 142 /* Capture samples in local storage */
 143 static int humidity_capture_sample(struct hid_sensor_hub_device *hsdev,
 144                                 unsigned int usage_id, size_t raw_len,
 145                                 char *raw_data, void *pdev)
 146 {
 147         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 148         struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 149
 150         switch (usage_id) {
 151         case HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY:
 152                 humid_st->scan.humidity_data = *(s32 *)raw_data;
 153
 154                 return 0;
 155         default:
 156                 return -EINVAL;
 157         }
 158 }
 159
 160 /* Parse report which is specific to an usage id */
 161 static int humidity_parse_report(struct platform_device *pdev,
 162                                 struct hid_sensor_hub_device *hsdev,
 163                                 struct iio_chan_spec *channels,
 164                                 unsigned int usage_id,
 165                                 struct hid_humidity_state *st)
 166 {
 167         int ret;
 168
 169         ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
 170                                         usage_id,
 171                                         HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
 172                                         &st->humidity_attr);
 173         if (ret < 0)
 174                 return ret;
 175
 176         humidity_adjust_channel_bit_mask(channels, 0, st->humidity_attr.size);
 177
 178         st->scale_precision = hid_sensor_format_scale(
 179                                                 HID_USAGE_SENSOR_HUMIDITY,
 180                                                 &st->humidity_attr,
 181                                                 &st->scale_pre_decml,
 182                                                 &st->scale_post_decml);
 183
 184         return ret;
 185 }
 186
 187 static struct hid_sensor_hub_callbacks humidity_callbacks = {
 188         .send_event = &humidity_proc_event,
 189         .capture_sample = &humidity_capture_sample,
 190 };
 191
 192 /* Function to initialize the processing for usage id */
 193 static int hid_humidity_probe(struct platform_device *pdev)
 194 {
 195         static const char *name = "humidity";
 196         struct iio_dev *indio_dev;
 197         struct hid_humidity_state *humid_st;
 198         struct iio_chan_spec *humid_chans;
 199         struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 200         int ret;
 201
 202         indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*humid_st));
 203         if (!indio_dev)
 204                 return -ENOMEM;
 205
 206         humid_st = iio_priv(indio_dev);
 207         humid_st->common_attributes.hsdev = hsdev;
 208         humid_st->common_attributes.pdev = pdev;
 209
 210         ret = hid_sensor_parse_common_attributes(hsdev,
 211                                         HID_USAGE_SENSOR_HUMIDITY,
 212                                         &humid_st->common_attributes,
 213                                         humidity_sensitivity_addresses,
 214                                         ARRAY_SIZE(humidity_sensitivity_addresses));
 215         if (ret)
 216                 return ret;
 217
 218         humid_chans = devm_kmemdup(&indio_dev->dev, humidity_channels,
 219                                         sizeof(humidity_channels), GFP_KERNEL);
 220         if (!humid_chans)
 221                 return -ENOMEM;
 222
 223         ret = humidity_parse_report(pdev, hsdev, humid_chans,
 224                                 HID_USAGE_SENSOR_HUMIDITY, humid_st);
 225         if (ret)
 226                 return ret;
 227
 228         indio_dev->channels = humid_chans;
 229         indio_dev->num_channels = ARRAY_SIZE(humidity_channels);
 230         indio_dev->info = &humidity_info;
 231         indio_dev->name = name;
 232         indio_dev->modes = INDIO_DIRECT_MODE;
 233
 234         atomic_set(&humid_st->common_attributes.data_ready, 0);
 235
 236         ret = hid_sensor_setup_trigger(indio_dev, name,
 237                                 &humid_st->common_attributes);
 238         if (ret)
 239                 return ret;
 240
 241         platform_set_drvdata(pdev, indio_dev);
 242
 243         humidity_callbacks.pdev = pdev;
 244         ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY,
 245                                         &humidity_callbacks);
 246         if (ret)
 247                 goto error_remove_trigger;
 248
 249         ret = iio_device_register(indio_dev);
 250         if (ret)
 251                 goto error_remove_callback;
 252
 253         return ret;
 254
 255 error_remove_callback:
 256         sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY);
 257 error_remove_trigger:
 258         hid_sensor_remove_trigger(indio_dev, &humid_st->common_attributes);
 259         return ret;
 260 }
 261
 262 /* Function to deinitialize the processing for usage id */
 263 static void hid_humidity_remove(struct platform_device *pdev)
 264 {
 265         struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 266         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 267         struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 268
 269         iio_device_unregister(indio_dev);
 270         sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY);
 271         hid_sensor_remove_trigger(indio_dev, &humid_st->common_attributes);
 272 }
 273
 274 static const struct platform_device_id hid_humidity_ids[] = {
 275         {
 276                 /* Format: HID-SENSOR-usage_id_in_hex_lowercase */
 277                 .name = "HID-SENSOR-200032",
 278         },
 279         { /* sentinel */ }
 280 };
 281 MODULE_DEVICE_TABLE(platform, hid_humidity_ids);
 282
 283 static struct platform_driver hid_humidity_platform_driver = {
 284         .id_table = hid_humidity_ids,
 285         .driver = {
 286                 .name   = KBUILD_MODNAME,
 287                 .pm     = &hid_sensor_pm_ops,
 288         },
 289         .probe          = hid_humidity_probe,
 290         .remove         = hid_humidity_remove,
 291 };
 292 module_platform_driver(hid_humidity_platform_driver);
 293
 294 MODULE_DESCRIPTION("HID Environmental humidity sensor");
 295 MODULE_AUTHOR("Song Hongyan <hongyan.song@intel.com>");
 296 MODULE_LICENSE("GPL v2");
 297 MODULE_IMPORT_NS("IIO_HID");