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         struct {
  32                 s32 temperature_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 temperature_channels[] = {
  43         {
  44                 .type = IIO_TEMP,
  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 temperature_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 temperature_read_raw(struct iio_dev *indio_dev,
  66                                 struct iio_chan_spec const *chan,
  67                                 int *val, int *val2, long mask)
  68 {
  69         struct temperature_state *temp_st = iio_priv(indio_dev);
  70
  71         switch (mask) {
  72         case IIO_CHAN_INFO_RAW:
  73                 if (chan->type != IIO_TEMP)
  74                         return -EINVAL;
  75                 hid_sensor_power_state(
  76                         &temp_st->common_attributes, true);
  77                 *val = sensor_hub_input_attr_get_raw_value(
  78                         temp_st->common_attributes.hsdev,
  79                         HID_USAGE_SENSOR_TEMPERATURE,
  80                         HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
  81                         temp_st->temperature_attr.report_id,
  82                         SENSOR_HUB_SYNC,
  83                         temp_st->temperature_attr.logical_minimum < 0);
  84                 hid_sensor_power_state(
  85                                 &temp_st->common_attributes,
  86                                 false);
  87
  88                 return IIO_VAL_INT;
  89
  90         case IIO_CHAN_INFO_SCALE:
  91                 *val = temp_st->scale_pre_decml;
  92                 *val2 = temp_st->scale_post_decml;
  93                 return temp_st->scale_precision;
  94
  95         case IIO_CHAN_INFO_OFFSET:
  96                 *val = temp_st->value_offset;
  97                 return IIO_VAL_INT;
  98
  99         case IIO_CHAN_INFO_SAMP_FREQ:
 100                 return hid_sensor_read_samp_freq_value(
 101                                 &temp_st->common_attributes, val, val2);
 102
 103         case IIO_CHAN_INFO_HYSTERESIS:
 104                 return hid_sensor_read_raw_hyst_value(
 105                                 &temp_st->common_attributes, val, val2);
 106         default:
 107                 return -EINVAL;
 108         }
 109 }
 110
 111 static int temperature_write_raw(struct iio_dev *indio_dev,
 112                                 struct iio_chan_spec const *chan,
 113                                 int val, int val2, long mask)
 114 {
 115         struct temperature_state *temp_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                                 &temp_st->common_attributes, val, val2);
 121         case IIO_CHAN_INFO_HYSTERESIS:
 122                 return hid_sensor_write_raw_hyst_value(
 123                                 &temp_st->common_attributes, val, val2);
 124         default:
 125                 return -EINVAL;
 126         }
 127 }
 128
 129 static const struct iio_info temperature_info = {
 130         .driver_module = THIS_MODULE,
 131         .read_raw = &temperature_read_raw,
 132         .write_raw = &temperature_write_raw,
 133 };
 134
 135 /* Callback handler to send event after all samples are received and captured */
 136 static int temperature_proc_event(struct hid_sensor_hub_device *hsdev,
 137                                 unsigned int usage_id, void *pdev)
 138 {
 139         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 140         struct temperature_state *temp_st = iio_priv(indio_dev);
 141
 142         if (atomic_read(&temp_st->common_attributes.data_ready))
 143                 iio_push_to_buffers_with_timestamp(indio_dev, &temp_st->scan,
 144                                                    iio_get_time_ns(indio_dev));
 145
 146         return 0;
 147 }
 148
 149 /* Capture samples in local storage */
 150 static int temperature_capture_sample(struct hid_sensor_hub_device *hsdev,
 151                                 unsigned int usage_id, size_t raw_len,
 152                                 char *raw_data, void *pdev)
 153 {
 154         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 155         struct temperature_state *temp_st = iio_priv(indio_dev);
 156
 157         switch (usage_id) {
 158         case HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE:
 159                 temp_st->scan.temperature_data = *(s32 *)raw_data;
 160                 return 0;
 161         default:
 162                 return -EINVAL;
 163         }
 164 }
 165
 166 /* Parse report which is specific to an usage id*/
 167 static int temperature_parse_report(struct platform_device *pdev,
 168                                 struct hid_sensor_hub_device *hsdev,
 169                                 struct iio_chan_spec *channels,
 170                                 unsigned int usage_id,
 171                                 struct temperature_state *st)
 172 {
 173         int ret;
 174
 175         ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
 176                         usage_id,
 177                         HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
 178                         &st->temperature_attr);
 179         if (ret < 0)
 180                 return ret;
 181
 182         temperature_adjust_channel_bit_mask(channels, 0,
 183                                         st->temperature_attr.size);
 184
 185         st->scale_precision = hid_sensor_format_scale(
 186                                 HID_USAGE_SENSOR_TEMPERATURE,
 187                                 &st->temperature_attr,
 188                                 &st->scale_pre_decml, &st->scale_post_decml);
 189
 190         /* Set Sensitivity field ids, when there is no individual modifier */
 191         if (st->common_attributes.sensitivity.index < 0)
 192                 sensor_hub_input_get_attribute_info(hsdev,
 193                         HID_FEATURE_REPORT, usage_id,
 194                         HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
 195                         HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
 196                         &st->common_attributes.sensitivity);
 197
 198         return ret;
 199 }
 200
 201 static struct hid_sensor_hub_callbacks temperature_callbacks = {
 202         .send_event = &temperature_proc_event,
 203         .capture_sample = &temperature_capture_sample,
 204 };
 205
 206 /* Function to initialize the processing for usage id */
 207 static int hid_temperature_probe(struct platform_device *pdev)
 208 {
 209         static const char *name = "temperature";
 210         struct iio_dev *indio_dev;
 211         struct temperature_state *temp_st;
 212         struct iio_chan_spec *temp_chans;
 213         struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 214         int ret;
 215
 216         indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*temp_st));
 217         if (!indio_dev)
 218                 return -ENOMEM;
 219
 220         temp_st = iio_priv(indio_dev);
 221         temp_st->common_attributes.hsdev = hsdev;
 222         temp_st->common_attributes.pdev = pdev;
 223
 224         ret = hid_sensor_parse_common_attributes(hsdev,
 225                                         HID_USAGE_SENSOR_TEMPERATURE,
 226                                         &temp_st->common_attributes);
 227         if (ret)
 228                 return ret;
 229
 230         temp_chans = devm_kmemdup(&indio_dev->dev, temperature_channels,
 231                                 sizeof(temperature_channels), GFP_KERNEL);
 232         if (!temp_chans)
 233                 return -ENOMEM;
 234
 235         ret = temperature_parse_report(pdev, hsdev, temp_chans,
 236                                 HID_USAGE_SENSOR_TEMPERATURE, temp_st);
 237         if (ret)
 238                 return ret;
 239
 240         indio_dev->channels = temp_chans;
 241         indio_dev->num_channels = ARRAY_SIZE(temperature_channels);
 242         indio_dev->dev.parent = &pdev->dev;
 243         indio_dev->info = &temperature_info;
 244         indio_dev->name = name;
 245         indio_dev->modes = INDIO_DIRECT_MODE;
 246
 247         ret = devm_iio_triggered_buffer_setup(&pdev->dev, indio_dev,
 248                                         &iio_pollfunc_store_time, NULL, NULL);
 249         if (ret)
 250                 return ret;
 251
 252         atomic_set(&temp_st->common_attributes.data_ready, 0);
 253         ret = hid_sensor_setup_trigger(indio_dev, name,
 254                                 &temp_st->common_attributes);
 255         if (ret)
 256                 return ret;
 257
 258         platform_set_drvdata(pdev, indio_dev);
 259
 260         temperature_callbacks.pdev = pdev;
 261         ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_TEMPERATURE,
 262                                         &temperature_callbacks);
 263         if (ret)
 264                 goto error_remove_trigger;
 265
 266         ret = devm_iio_device_register(indio_dev->dev.parent, indio_dev);
 267         if (ret)
 268                 goto error_remove_callback;
 269
 270         return ret;
 271
 272 error_remove_callback:
 273         sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TEMPERATURE);
 274 error_remove_trigger:
 275         hid_sensor_remove_trigger(&temp_st->common_attributes);
 276         return ret;
 277 }
 278
 279 /* Function to deinitialize the processing for usage id */
 280 static int hid_temperature_remove(struct platform_device *pdev)
 281 {
 282         struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 283         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 284         struct temperature_state *temp_st = iio_priv(indio_dev);
 285
 286         sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TEMPERATURE);
 287         hid_sensor_remove_trigger(&temp_st->common_attributes);
 288
 289         return 0;
 290 }
 291
 292 static const struct platform_device_id hid_temperature_ids[] = {
 293         {
 294                 /* Format: HID-SENSOR-usage_id_in_hex_lowercase */
 295                 .name = "HID-SENSOR-200033",
 296         },
 297         { /* sentinel */ }
 298 };
 299 MODULE_DEVICE_TABLE(platform, hid_temperature_ids);
 300
 301 static struct platform_driver hid_temperature_platform_driver = {
 302         .id_table = hid_temperature_ids,
 303         .driver = {
 304                 .name   = "temperature-sensor",
 305                 .pm     = &hid_sensor_pm_ops,
 306         },
 307         .probe          = hid_temperature_probe,
 308         .remove         = hid_temperature_remove,
 309 };
 310 module_platform_driver(hid_temperature_platform_driver);
 311
 312 MODULE_DESCRIPTION("HID Environmental temperature sensor");
 313 MODULE_AUTHOR("Song Hongyan <hongyan.song@intel.com>");
 314 MODULE_LICENSE("GPL v2");