drivers/rtc/rtc-hid-sensor-time.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * HID Sensor Time Driver
   4  * Copyright (c) 2012, Alexander Holler.
   5  */
   6 #include <linux/device.h>
   7 #include <linux/platform_device.h>
   8 #include <linux/module.h>
   9 #include <linux/hid-sensor-hub.h>
  10 #include <linux/iio/iio.h>
  11 #include <linux/rtc.h>
  12
  13 enum hid_time_channel {
  14         CHANNEL_SCAN_INDEX_YEAR,
  15         CHANNEL_SCAN_INDEX_MONTH,
  16         CHANNEL_SCAN_INDEX_DAY,
  17         CHANNEL_SCAN_INDEX_HOUR,
  18         CHANNEL_SCAN_INDEX_MINUTE,
  19         CHANNEL_SCAN_INDEX_SECOND,
  20         TIME_RTC_CHANNEL_MAX,
  21 };
  22
  23 struct hid_time_state {
  24         struct hid_sensor_hub_callbacks callbacks;
  25         struct hid_sensor_common common_attributes;
  26         struct hid_sensor_hub_attribute_info info[TIME_RTC_CHANNEL_MAX];
  27         struct rtc_time last_time;
  28         spinlock_t lock_last_time;
  29         struct completion comp_last_time;
  30         struct rtc_time time_buf;
  31         struct rtc_device *rtc;
  32 };
  33
  34 static const u32 hid_time_addresses[TIME_RTC_CHANNEL_MAX] = {
  35         HID_USAGE_SENSOR_TIME_YEAR,
  36         HID_USAGE_SENSOR_TIME_MONTH,
  37         HID_USAGE_SENSOR_TIME_DAY,
  38         HID_USAGE_SENSOR_TIME_HOUR,
  39         HID_USAGE_SENSOR_TIME_MINUTE,
  40         HID_USAGE_SENSOR_TIME_SECOND,
  41 };
  42
  43 /* Channel names for verbose error messages */
  44 static const char * const hid_time_channel_names[TIME_RTC_CHANNEL_MAX] = {
  45         "year", "month", "day", "hour", "minute", "second",
  46 };
  47
  48 /* Callback handler to send event after all samples are received and captured */
  49 static int hid_time_proc_event(struct hid_sensor_hub_device *hsdev,
  50                                 unsigned usage_id, void *priv)
  51 {
  52         unsigned long flags;
  53         struct hid_time_state *time_state = platform_get_drvdata(priv);
  54
  55         spin_lock_irqsave(&time_state->lock_last_time, flags);
  56         time_state->last_time = time_state->time_buf;
  57         spin_unlock_irqrestore(&time_state->lock_last_time, flags);
  58         complete(&time_state->comp_last_time);
  59         return 0;
  60 }
  61
  62 static u32 hid_time_value(size_t raw_len, char *raw_data)
  63 {
  64         switch (raw_len) {
  65         case 1:
  66                 return *(u8 *)raw_data;
  67         case 2:
  68                 return *(u16 *)raw_data;
  69         case 4:
  70                 return *(u32 *)raw_data;
  71         default:
  72                 return (u32)(~0U); /* 0xff... or -1 to denote an error */
  73         }
  74 }
  75
  76 static int hid_time_capture_sample(struct hid_sensor_hub_device *hsdev,
  77                                 unsigned usage_id, size_t raw_len,
  78                                 char *raw_data, void *priv)
  79 {
  80         struct hid_time_state *time_state = platform_get_drvdata(priv);
  81         struct rtc_time *time_buf = &time_state->time_buf;
  82
  83         switch (usage_id) {
  84         case HID_USAGE_SENSOR_TIME_YEAR:
  85                 /*
  86                  * The draft for HID-sensors (HUTRR39) currently doesn't define
  87                  * the range for the year attribute. Therefor we support
  88                  * 8 bit (0-99) and 16 or 32 bits (full) as size for the year.
  89                  */
  90                 if (raw_len == 1) {
  91                         time_buf->tm_year = *(u8 *)raw_data;
  92                         if (time_buf->tm_year < 70)
  93                                 /* assume we are in 1970...2069 */
  94                                 time_buf->tm_year += 100;
  95                 } else
  96                         time_buf->tm_year =
  97                                 (int)hid_time_value(raw_len, raw_data)-1900;
  98                 break;
  99         case HID_USAGE_SENSOR_TIME_MONTH:
 100                 /* sensors are sending the month as 1-12, we need 0-11 */
 101                 time_buf->tm_mon = (int)hid_time_value(raw_len, raw_data)-1;
 102                 break;
 103         case HID_USAGE_SENSOR_TIME_DAY:
 104                 time_buf->tm_mday = (int)hid_time_value(raw_len, raw_data);
 105                 break;
 106         case HID_USAGE_SENSOR_TIME_HOUR:
 107                 time_buf->tm_hour = (int)hid_time_value(raw_len, raw_data);
 108                 break;
 109         case HID_USAGE_SENSOR_TIME_MINUTE:
 110                 time_buf->tm_min = (int)hid_time_value(raw_len, raw_data);
 111                 break;
 112         case HID_USAGE_SENSOR_TIME_SECOND:
 113                 time_buf->tm_sec = (int)hid_time_value(raw_len, raw_data);
 114                 break;
 115         default:
 116                 return -EINVAL;
 117         }
 118         return 0;
 119 }
 120
 121 /* small helper, haven't found any other way */
 122 static const char *hid_time_attrib_name(u32 attrib_id)
 123 {
 124         static const char unknown[] = "unknown";
 125         unsigned i;
 126
 127         for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i) {
 128                 if (hid_time_addresses[i] == attrib_id)
 129                         return hid_time_channel_names[i];
 130         }
 131         return unknown; /* should never happen */
 132 }
 133
 134 static int hid_time_parse_report(struct platform_device *pdev,
 135                                 struct hid_sensor_hub_device *hsdev,
 136                                 unsigned usage_id,
 137                                 struct hid_time_state *time_state)
 138 {
 139         int report_id, i;
 140
 141         for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i)
 142                 if (sensor_hub_input_get_attribute_info(hsdev,
 143                                 HID_INPUT_REPORT, usage_id,
 144                                 hid_time_addresses[i],
 145                                 &time_state->info[i]) < 0)
 146                         return -EINVAL;
 147         /* Check the (needed) attributes for sanity */
 148         report_id = time_state->info[0].report_id;
 149         if (report_id < 0) {
 150                 dev_err(&pdev->dev, "bad report ID!\n");
 151                 return -EINVAL;
 152         }
 153         for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i) {
 154                 if (time_state->info[i].report_id != report_id) {
 155                         dev_err(&pdev->dev,
 156                                 "not all needed attributes inside the same report!\n");
 157                         return -EINVAL;
 158                 }
 159                 if (time_state->info[i].size == 3 ||
 160                                 time_state->info[i].size > 4) {
 161                         dev_err(&pdev->dev,
 162                                 "attribute '%s' not 8, 16 or 32 bits wide!\n",
 163                                 hid_time_attrib_name(
 164                                         time_state->info[i].attrib_id));
 165                         return -EINVAL;
 166                 }
 167                 if (time_state->info[i].units !=
 168                                 HID_USAGE_SENSOR_UNITS_NOT_SPECIFIED &&
 169                                 /* allow attribute seconds with unit seconds */
 170                                 !(time_state->info[i].attrib_id ==
 171                                 HID_USAGE_SENSOR_TIME_SECOND &&
 172                                 time_state->info[i].units ==
 173                                 HID_USAGE_SENSOR_UNITS_SECOND)) {
 174                         dev_err(&pdev->dev,
 175                                 "attribute '%s' hasn't a unit of type 'none'!\n",
 176                                 hid_time_attrib_name(
 177                                         time_state->info[i].attrib_id));
 178                         return -EINVAL;
 179                 }
 180                 if (time_state->info[i].unit_expo) {
 181                         dev_err(&pdev->dev,
 182                                 "attribute '%s' hasn't a unit exponent of 1!\n",
 183                                 hid_time_attrib_name(
 184                                         time_state->info[i].attrib_id));
 185                         return -EINVAL;
 186                 }
 187         }
 188
 189         return 0;
 190 }
 191
 192 static int hid_rtc_read_time(struct device *dev, struct rtc_time *tm)
 193 {
 194         unsigned long flags;
 195         struct hid_time_state *time_state = dev_get_drvdata(dev);
 196         int ret;
 197
 198         reinit_completion(&time_state->comp_last_time);
 199         /* get a report with all values through requesting one value */
 200         sensor_hub_input_attr_get_raw_value(time_state->common_attributes.hsdev,
 201                         HID_USAGE_SENSOR_TIME, hid_time_addresses[0],
 202                         time_state->info[0].report_id, SENSOR_HUB_SYNC, false);
 203         /* wait for all values (event) */
 204         ret = wait_for_completion_killable_timeout(
 205                         &time_state->comp_last_time, HZ*6);
 206         if (ret > 0) {
 207                 /* no error */
 208                 spin_lock_irqsave(&time_state->lock_last_time, flags);
 209                 *tm = time_state->last_time;
 210                 spin_unlock_irqrestore(&time_state->lock_last_time, flags);
 211                 return 0;
 212         }
 213         if (!ret)
 214                 return -EIO; /* timeouted */
 215         return ret; /* killed (-ERESTARTSYS) */
 216 }
 217
 218 static const struct rtc_class_ops hid_time_rtc_ops = {
 219         .read_time = hid_rtc_read_time,
 220 };
 221
 222 static int hid_time_probe(struct platform_device *pdev)
 223 {
 224         int ret = 0;
 225         struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 226         struct hid_time_state *time_state = devm_kzalloc(&pdev->dev,
 227                 sizeof(struct hid_time_state), GFP_KERNEL);
 228
 229         if (time_state == NULL)
 230                 return -ENOMEM;
 231
 232         platform_set_drvdata(pdev, time_state);
 233
 234         spin_lock_init(&time_state->lock_last_time);
 235         init_completion(&time_state->comp_last_time);
 236         time_state->common_attributes.hsdev = hsdev;
 237         time_state->common_attributes.pdev = pdev;
 238
 239         ret = hid_sensor_parse_common_attributes(hsdev,
 240                                 HID_USAGE_SENSOR_TIME,
 241                                 &time_state->common_attributes);
 242         if (ret) {
 243                 dev_err(&pdev->dev, "failed to setup common attributes!\n");
 244                 return ret;
 245         }
 246
 247         ret = hid_time_parse_report(pdev, hsdev, HID_USAGE_SENSOR_TIME,
 248                                         time_state);
 249         if (ret) {
 250                 dev_err(&pdev->dev, "failed to setup attributes!\n");
 251                 return ret;
 252         }
 253
 254         time_state->callbacks.send_event = hid_time_proc_event;
 255         time_state->callbacks.capture_sample = hid_time_capture_sample;
 256         time_state->callbacks.pdev = pdev;
 257         ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_TIME,
 258                                         &time_state->callbacks);
 259         if (ret < 0) {
 260                 dev_err(&pdev->dev, "register callback failed!\n");
 261                 return ret;
 262         }
 263
 264         ret = sensor_hub_device_open(hsdev);
 265         if (ret) {
 266                 dev_err(&pdev->dev, "failed to open sensor hub device!\n");
 267                 goto err_open;
 268         }
 269
 270         /*
 271          * Enable HID input processing early in order to be able to read the
 272          * clock already in devm_rtc_device_register().
 273          */
 274         hid_device_io_start(hsdev->hdev);
 275
 276         time_state->rtc = devm_rtc_device_register(&pdev->dev,
 277                                         "hid-sensor-time", &hid_time_rtc_ops,
 278                                         THIS_MODULE);
 279
 280         if (IS_ERR(time_state->rtc)) {
 281                 hid_device_io_stop(hsdev->hdev);
 282                 ret = PTR_ERR(time_state->rtc);
 283                 time_state->rtc = NULL;
 284                 dev_err(&pdev->dev, "rtc device register failed!\n");
 285                 goto err_rtc;
 286         }
 287
 288         return ret;
 289
 290 err_rtc:
 291         sensor_hub_device_close(hsdev);
 292 err_open:
 293         sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TIME);
 294         return ret;
 295 }
 296
 297 static int hid_time_remove(struct platform_device *pdev)
 298 {
 299         struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 300
 301         sensor_hub_device_close(hsdev);
 302         sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TIME);
 303
 304         return 0;
 305 }
 306
 307 static const struct platform_device_id hid_time_ids[] = {
 308         {
 309                 /* Format: HID-SENSOR-usage_id_in_hex_lowercase */
 310                 .name = "HID-SENSOR-2000a0",
 311         },
 312         { /* sentinel */ }
 313 };
 314 MODULE_DEVICE_TABLE(platform, hid_time_ids);
 315
 316 static struct platform_driver hid_time_platform_driver = {
 317         .id_table = hid_time_ids,
 318         .driver = {
 319                 .name   = KBUILD_MODNAME,
 320         },
 321         .probe          = hid_time_probe,
 322         .remove         = hid_time_remove,
 323 };
 324 module_platform_driver(hid_time_platform_driver);
 325
 326 MODULE_DESCRIPTION("HID Sensor Time");
 327 MODULE_AUTHOR("Alexander Holler <holler@ahsoftware.de>");
 328 MODULE_LICENSE("GPL");