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