drivers/iio/temperature/hid-sensor-temperature.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 "../common/hid-sensors/hid-sensor-trigger.h"
  27
  28 struct temperature_state {
  29         struct hid_sensor_common common_attributes;
  30         struct hid_sensor_hub_attribute_info temperature_attr;
  31         s32 temperature_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 temperature_channels[] = {
  40         {
  41                 .type = IIO_TEMP,
  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(3),
  49 };
  50
  51 /* Adjust channel real bits based on report descriptor */
  52 static void temperature_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 temperature_read_raw(struct iio_dev *indio_dev,
  63                                 struct iio_chan_spec const *chan,
  64                                 int *val, int *val2, long mask)
  65 {
  66         struct temperature_state *temp_st = iio_priv(indio_dev);
  67
  68         switch (mask) {
  69         case IIO_CHAN_INFO_RAW:
  70                 if (chan->type != IIO_TEMP)
  71                         return -EINVAL;
  72                 hid_sensor_power_state(
  73                         &temp_st->common_attributes, true);
  74                 *val = sensor_hub_input_attr_get_raw_value(
  75                         temp_st->common_attributes.hsdev,
  76                         HID_USAGE_SENSOR_TEMPERATURE,
  77                         HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
  78                         temp_st->temperature_attr.report_id,
  79                         SENSOR_HUB_SYNC);
  80                 hid_sensor_power_state(
  81                                 &temp_st->common_attributes,
  82                                 false);
  83
  84                 return IIO_VAL_INT;
  85
  86         case IIO_CHAN_INFO_SCALE:
  87                 *val = temp_st->scale_pre_decml;
  88                 *val2 = temp_st->scale_post_decml;
  89                 return temp_st->scale_precision;
  90
  91         case IIO_CHAN_INFO_OFFSET:
  92                 *val = temp_st->value_offset;
  93                 return IIO_VAL_INT;
  94
  95         case IIO_CHAN_INFO_SAMP_FREQ:
  96                 return hid_sensor_read_samp_freq_value(
  97                                 &temp_st->common_attributes, val, val2);
  98
  99         case IIO_CHAN_INFO_HYSTERESIS:
 100                 return hid_sensor_read_raw_hyst_value(
 101                                 &temp_st->common_attributes, val, val2);
 102         default:
 103                 return -EINVAL;
 104         }
 105 }
 106
 107 static int temperature_write_raw(struct iio_dev *indio_dev,
 108                                 struct iio_chan_spec const *chan,
 109                                 int val, int val2, long mask)
 110 {
 111         struct temperature_state *temp_st = iio_priv(indio_dev);
 112
 113         switch (mask) {
 114         case IIO_CHAN_INFO_SAMP_FREQ:
 115                 return hid_sensor_write_samp_freq_value(
 116                                 &temp_st->common_attributes, val, val2);
 117         case IIO_CHAN_INFO_HYSTERESIS:
 118                 return hid_sensor_write_raw_hyst_value(
 119                                 &temp_st->common_attributes, val, val2);
 120         default:
 121                 return -EINVAL;
 122         }
 123 }
 124
 125 static const struct iio_info temperature_info = {
 126         .read_raw = &temperature_read_raw,
 127         .write_raw = &temperature_write_raw,
 128 };
 129
 130 /* Callback handler to send event after all samples are received and captured */
 131 static int temperature_proc_event(struct hid_sensor_hub_device *hsdev,
 132                                 unsigned int usage_id, void *pdev)
 133 {
 134         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 135         struct temperature_state *temp_st = iio_priv(indio_dev);
 136
 137         if (atomic_read(&temp_st->common_attributes.data_ready))
 138                 iio_push_to_buffers_with_timestamp(indio_dev,
 139                                 &temp_st->temperature_data,
 140                                 iio_get_time_ns(indio_dev));
 141
 142         return 0;
 143 }
 144
 145 /* Capture samples in local storage */
 146 static int temperature_capture_sample(struct hid_sensor_hub_device *hsdev,
 147                                 unsigned int usage_id, size_t raw_len,
 148                                 char *raw_data, void *pdev)
 149 {
 150         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 151         struct temperature_state *temp_st = iio_priv(indio_dev);
 152
 153         switch (usage_id) {
 154         case HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE:
 155                 temp_st->temperature_data = *(s32 *)raw_data;
 156                 return 0;
 157         default:
 158                 return -EINVAL;
 159         }
 160 }
 161
 162 /* Parse report which is specific to an usage id*/
 163 static int temperature_parse_report(struct platform_device *pdev,
 164                                 struct hid_sensor_hub_device *hsdev,
 165                                 struct iio_chan_spec *channels,
 166                                 unsigned int usage_id,
 167                                 struct temperature_state *st)
 168 {
 169         int ret;
 170
 171         ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
 172                         usage_id,
 173                         HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
 174                         &st->temperature_attr);
 175         if (ret < 0)
 176                 return ret;
 177
 178         temperature_adjust_channel_bit_mask(channels, 0,
 179                                         st->temperature_attr.size);
 180
 181         st->scale_precision = hid_sensor_format_scale(
 182                                 HID_USAGE_SENSOR_TEMPERATURE,
 183                                 &st->temperature_attr,
 184                                 &st->scale_pre_decml, &st->scale_post_decml);
 185
 186         /* Set Sensitivity field ids, when there is no individual modifier */
 187         if (st->common_attributes.sensitivity.index < 0)
 188                 sensor_hub_input_get_attribute_info(hsdev,
 189                         HID_FEATURE_REPORT, usage_id,
 190                         HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
 191                         HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
 192                         &st->common_attributes.sensitivity);
 193
 194         return ret;
 195 }
 196
 197 static struct hid_sensor_hub_callbacks temperature_callbacks = {
 198         .send_event = &temperature_proc_event,
 199         .capture_sample = &temperature_capture_sample,
 200 };
 201
 202 /* Function to initialize the processing for usage id */
 203 static int hid_temperature_probe(struct platform_device *pdev)
 204 {
 205         static const char *name = "temperature";
 206         struct iio_dev *indio_dev;
 207         struct temperature_state *temp_st;
 208         struct iio_chan_spec *temp_chans;
 209         struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 210         int ret;
 211
 212         indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*temp_st));
 213         if (!indio_dev)
 214                 return -ENOMEM;
 215
 216         temp_st = iio_priv(indio_dev);
 217         temp_st->common_attributes.hsdev = hsdev;
 218         temp_st->common_attributes.pdev = pdev;
 219
 220         ret = hid_sensor_parse_common_attributes(hsdev,
 221                                         HID_USAGE_SENSOR_TEMPERATURE,
 222                                         &temp_st->common_attributes);
 223         if (ret)
 224                 return ret;
 225
 226         temp_chans = devm_kmemdup(&indio_dev->dev, temperature_channels,
 227                                 sizeof(temperature_channels), GFP_KERNEL);
 228         if (!temp_chans)
 229                 return -ENOMEM;
 230
 231         ret = temperature_parse_report(pdev, hsdev, temp_chans,
 232                                 HID_USAGE_SENSOR_TEMPERATURE, temp_st);
 233         if (ret)
 234                 return ret;
 235
 236         indio_dev->channels = temp_chans;
 237         indio_dev->num_channels = ARRAY_SIZE(temperature_channels);
 238         indio_dev->dev.parent = &pdev->dev;
 239         indio_dev->info = &temperature_info;
 240         indio_dev->name = name;
 241         indio_dev->modes = INDIO_DIRECT_MODE;
 242
 243         ret = devm_iio_triggered_buffer_setup(&pdev->dev, indio_dev,
 244                                         &iio_pollfunc_store_time, NULL, NULL);
 245         if (ret)
 246                 return ret;
 247
 248         atomic_set(&temp_st->common_attributes.data_ready, 0);
 249         ret = hid_sensor_setup_trigger(indio_dev, name,
 250                                 &temp_st->common_attributes);
 251         if (ret)
 252                 return ret;
 253
 254         platform_set_drvdata(pdev, indio_dev);
 255
 256         temperature_callbacks.pdev = pdev;
 257         ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_TEMPERATURE,
 258                                         &temperature_callbacks);
 259         if (ret)
 260                 goto error_remove_trigger;
 261
 262         ret = devm_iio_device_register(indio_dev->dev.parent, indio_dev);
 263         if (ret)
 264                 goto error_remove_callback;
 265
 266         return ret;
 267
 268 error_remove_callback:
 269         sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TEMPERATURE);
 270 error_remove_trigger:
 271         hid_sensor_remove_trigger(&temp_st->common_attributes);
 272         return ret;
 273 }
 274
 275 /* Function to deinitialize the processing for usage id */
 276 static int hid_temperature_remove(struct platform_device *pdev)
 277 {
 278         struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 279         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 280         struct temperature_state *temp_st = iio_priv(indio_dev);
 281
 282         sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TEMPERATURE);
 283         hid_sensor_remove_trigger(&temp_st->common_attributes);
 284
 285         return 0;
 286 }
 287
 288 static const struct platform_device_id hid_temperature_ids[] = {
 289         {
 290                 /* Format: HID-SENSOR-usage_id_in_hex_lowercase */
 291                 .name = "HID-SENSOR-200033",
 292         },
 293         { /* sentinel */ }
 294 };
 295 MODULE_DEVICE_TABLE(platform, hid_temperature_ids);
 296
 297 static struct platform_driver hid_temperature_platform_driver = {
 298         .id_table = hid_temperature_ids,
 299         .driver = {
 300                 .name   = "temperature-sensor",
 301                 .pm     = &hid_sensor_pm_ops,
 302         },
 303         .probe          = hid_temperature_probe,
 304         .remove         = hid_temperature_remove,
 305 };
 306 module_platform_driver(hid_temperature_platform_driver);
 307
 308 MODULE_DESCRIPTION("HID Environmental temperature sensor");
 309 MODULE_AUTHOR("Song Hongyan <hongyan.song@intel.com>");
 310 MODULE_LICENSE("GPL v2");