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

   1 /*
   2  * HID Sensor Time Driver
   3  * Copyright (c) 2012, Alexander Holler.
   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; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  17  *
  18  */
  19 #include <linux/device.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/module.h>
  22 #include <linux/hid-sensor-hub.h>
  23 #include <linux/iio/iio.h>
  24 #include <linux/rtc.h>
  25
  26 enum hid_time_channel {
  27         CHANNEL_SCAN_INDEX_YEAR,
  28         CHANNEL_SCAN_INDEX_MONTH,
  29         CHANNEL_SCAN_INDEX_DAY,
  30         CHANNEL_SCAN_INDEX_HOUR,
  31         CHANNEL_SCAN_INDEX_MINUTE,
  32         CHANNEL_SCAN_INDEX_SECOND,
  33         TIME_RTC_CHANNEL_MAX,
  34 };
  35
  36 struct hid_time_state {
  37         struct hid_sensor_hub_callbacks callbacks;
  38         struct hid_sensor_common common_attributes;
  39         struct hid_sensor_hub_attribute_info info[TIME_RTC_CHANNEL_MAX];
  40         struct rtc_time last_time;
  41         spinlock_t lock_last_time;
  42         struct completion comp_last_time;
  43         struct rtc_time time_buf;
  44         struct rtc_device *rtc;
  45 };
  46
  47 static const u32 hid_time_addresses[TIME_RTC_CHANNEL_MAX] = {
  48         HID_USAGE_SENSOR_TIME_YEAR,
  49         HID_USAGE_SENSOR_TIME_MONTH,
  50         HID_USAGE_SENSOR_TIME_DAY,
  51         HID_USAGE_SENSOR_TIME_HOUR,
  52         HID_USAGE_SENSOR_TIME_MINUTE,
  53         HID_USAGE_SENSOR_TIME_SECOND,
  54 };
  55
  56 /* Channel names for verbose error messages */
  57 static const char * const hid_time_channel_names[TIME_RTC_CHANNEL_MAX] = {
  58         "year", "month", "day", "hour", "minute", "second",
  59 };
  60
  61 /* Callback handler to send event after all samples are received and captured */
  62 static int hid_time_proc_event(struct hid_sensor_hub_device *hsdev,
  63                                 unsigned usage_id, void *priv)
  64 {
  65         unsigned long flags;
  66         struct hid_time_state *time_state = platform_get_drvdata(priv);
  67
  68         spin_lock_irqsave(&time_state->lock_last_time, flags);
  69         time_state->last_time = time_state->time_buf;
  70         spin_unlock_irqrestore(&time_state->lock_last_time, flags);
  71         complete(&time_state->comp_last_time);
  72         return 0;
  73 }
  74
  75 static u32 hid_time_value(size_t raw_len, char *raw_data)
  76 {
  77         switch (raw_len) {
  78         case 1:
  79                 return *(u8 *)raw_data;
  80         case 2:
  81                 return *(u16 *)raw_data;
  82         case 4:
  83                 return *(u32 *)raw_data;
  84         default:
  85                 return (u32)(~0U); /* 0xff... or -1 to denote an error */
  86         }
  87 }
  88
  89 static int hid_time_capture_sample(struct hid_sensor_hub_device *hsdev,
  90                                 unsigned usage_id, size_t raw_len,
  91                                 char *raw_data, void *priv)
  92 {
  93         struct hid_time_state *time_state = platform_get_drvdata(priv);
  94         struct rtc_time *time_buf = &time_state->time_buf;
  95
  96         switch (usage_id) {
  97         case HID_USAGE_SENSOR_TIME_YEAR:
  98                 /*
  99                  * The draft for HID-sensors (HUTRR39) currently doesn't define
 100                  * the range for the year attribute. Therefor we support
 101                  * 8 bit (0-99) and 16 or 32 bits (full) as size for the year.
 102                  */
 103                 if (raw_len == 1) {
 104                         time_buf->tm_year = *(u8 *)raw_data;
 105                         if (time_buf->tm_year < 70)
 106                                 /* assume we are in 1970...2069 */
 107                                 time_buf->tm_year += 100;
 108                 } else
 109                         time_buf->tm_year =
 110                                 (int)hid_time_value(raw_len, raw_data)-1900;
 111                 break;
 112         case HID_USAGE_SENSOR_TIME_MONTH:
 113                 /* sensors are sending the month as 1-12, we need 0-11 */
 114                 time_buf->tm_mon = (int)hid_time_value(raw_len, raw_data)-1;
 115                 break;
 116         case HID_USAGE_SENSOR_TIME_DAY:
 117                 time_buf->tm_mday = (int)hid_time_value(raw_len, raw_data);
 118                 break;
 119         case HID_USAGE_SENSOR_TIME_HOUR:
 120                 time_buf->tm_hour = (int)hid_time_value(raw_len, raw_data);
 121                 break;
 122         case HID_USAGE_SENSOR_TIME_MINUTE:
 123                 time_buf->tm_min = (int)hid_time_value(raw_len, raw_data);
 124                 break;
 125         case HID_USAGE_SENSOR_TIME_SECOND:
 126                 time_buf->tm_sec = (int)hid_time_value(raw_len, raw_data);
 127                 break;
 128         default:
 129                 return -EINVAL;
 130         }
 131         return 0;
 132 }
 133
 134 /* small helper, haven't found any other way */
 135 static const char *hid_time_attrib_name(u32 attrib_id)
 136 {
 137         static const char unknown[] = "unknown";
 138         unsigned i;
 139
 140         for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i) {
 141                 if (hid_time_addresses[i] == attrib_id)
 142                         return hid_time_channel_names[i];
 143         }
 144         return unknown; /* should never happen */
 145 }
 146
 147 static int hid_time_parse_report(struct platform_device *pdev,
 148                                 struct hid_sensor_hub_device *hsdev,
 149                                 unsigned usage_id,
 150                                 struct hid_time_state *time_state)
 151 {
 152         int report_id, i;
 153
 154         for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i)
 155                 if (sensor_hub_input_get_attribute_info(hsdev,
 156                                 HID_INPUT_REPORT, usage_id,
 157                                 hid_time_addresses[i],
 158                                 &time_state->info[i]) < 0)
 159                         return -EINVAL;
 160         /* Check the (needed) attributes for sanity */
 161         report_id = time_state->info[0].report_id;
 162         if (report_id < 0) {
 163                 dev_err(&pdev->dev, "bad report ID!\n");
 164                 return -EINVAL;
 165         }
 166         for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i) {
 167                 if (time_state->info[i].report_id != report_id) {
 168                         dev_err(&pdev->dev,
 169                                 "not all needed attributes inside the same report!\n");
 170                         return -EINVAL;
 171                 }
 172                 if (time_state->info[i].size == 3 ||
 173                                 time_state->info[i].size > 4) {
 174                         dev_err(&pdev->dev,
 175                                 "attribute '%s' not 8, 16 or 32 bits wide!\n",
 176                                 hid_time_attrib_name(
 177                                         time_state->info[i].attrib_id));
 178                         return -EINVAL;
 179                 }
 180                 if (time_state->info[i].units !=
 181                                 HID_USAGE_SENSOR_UNITS_NOT_SPECIFIED &&
 182                                 /* allow attribute seconds with unit seconds */
 183                                 !(time_state->info[i].attrib_id ==
 184                                 HID_USAGE_SENSOR_TIME_SECOND &&
 185                                 time_state->info[i].units ==
 186                                 HID_USAGE_SENSOR_UNITS_SECOND)) {
 187                         dev_err(&pdev->dev,
 188                                 "attribute '%s' hasn't a unit of type 'none'!\n",
 189                                 hid_time_attrib_name(
 190                                         time_state->info[i].attrib_id));
 191                         return -EINVAL;
 192                 }
 193                 if (time_state->info[i].unit_expo) {
 194                         dev_err(&pdev->dev,
 195                                 "attribute '%s' hasn't a unit exponent of 1!\n",
 196                                 hid_time_attrib_name(
 197                                         time_state->info[i].attrib_id));
 198                         return -EINVAL;
 199                 }
 200         }
 201
 202         return 0;
 203 }
 204
 205 static int hid_rtc_read_time(struct device *dev, struct rtc_time *tm)
 206 {
 207         unsigned long flags;
 208         struct hid_time_state *time_state =
 209                 platform_get_drvdata(to_platform_device(dev));
 210         int ret;
 211
 212         reinit_completion(&time_state->comp_last_time);
 213         /* get a report with all values through requesting one value */
 214         sensor_hub_input_attr_get_raw_value(time_state->common_attributes.hsdev,
 215                         HID_USAGE_SENSOR_TIME, hid_time_addresses[0],
 216                         time_state->info[0].report_id, SENSOR_HUB_SYNC);
 217         /* wait for all values (event) */
 218         ret = wait_for_completion_killable_timeout(
 219                         &time_state->comp_last_time, HZ*6);
 220         if (ret > 0) {
 221                 /* no error */
 222                 spin_lock_irqsave(&time_state->lock_last_time, flags);
 223                 *tm = time_state->last_time;
 224                 spin_unlock_irqrestore(&time_state->lock_last_time, flags);
 225                 return 0;
 226         }
 227         if (!ret)
 228                 return -EIO; /* timeouted */
 229         return ret; /* killed (-ERESTARTSYS) */
 230 }
 231
 232 static const struct rtc_class_ops hid_time_rtc_ops = {
 233         .read_time = hid_rtc_read_time,
 234 };
 235
 236 static int hid_time_probe(struct platform_device *pdev)
 237 {
 238         int ret = 0;
 239         struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 240         struct hid_time_state *time_state = devm_kzalloc(&pdev->dev,
 241                 sizeof(struct hid_time_state), GFP_KERNEL);
 242
 243         if (time_state == NULL)
 244                 return -ENOMEM;
 245
 246         platform_set_drvdata(pdev, time_state);
 247
 248         spin_lock_init(&time_state->lock_last_time);
 249         init_completion(&time_state->comp_last_time);
 250         time_state->common_attributes.hsdev = hsdev;
 251         time_state->common_attributes.pdev = pdev;
 252
 253         ret = hid_sensor_parse_common_attributes(hsdev,
 254                                 HID_USAGE_SENSOR_TIME,
 255                                 &time_state->common_attributes);
 256         if (ret) {
 257                 dev_err(&pdev->dev, "failed to setup common attributes!\n");
 258                 return ret;
 259         }
 260
 261         ret = hid_time_parse_report(pdev, hsdev, HID_USAGE_SENSOR_TIME,
 262                                         time_state);
 263         if (ret) {
 264                 dev_err(&pdev->dev, "failed to setup attributes!\n");
 265                 return ret;
 266         }
 267
 268         time_state->callbacks.send_event = hid_time_proc_event;
 269         time_state->callbacks.capture_sample = hid_time_capture_sample;
 270         time_state->callbacks.pdev = pdev;
 271         ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_TIME,
 272                                         &time_state->callbacks);
 273         if (ret < 0) {
 274                 dev_err(&pdev->dev, "register callback failed!\n");
 275                 return ret;
 276         }
 277
 278         ret = sensor_hub_device_open(hsdev);
 279         if (ret) {
 280                 dev_err(&pdev->dev, "failed to open sensor hub device!\n");
 281                 goto err_open;
 282         }
 283
 284         /*
 285          * Enable HID input processing early in order to be able to read the
 286          * clock already in devm_rtc_device_register().
 287          */
 288         hid_device_io_start(hsdev->hdev);
 289
 290         time_state->rtc = devm_rtc_device_register(&pdev->dev,
 291                                         "hid-sensor-time", &hid_time_rtc_ops,
 292                                         THIS_MODULE);
 293
 294         if (IS_ERR_OR_NULL(time_state->rtc)) {
 295                 hid_device_io_stop(hsdev->hdev);
 296                 ret = time_state->rtc ? PTR_ERR(time_state->rtc) : -ENODEV;
 297                 time_state->rtc = NULL;
 298                 dev_err(&pdev->dev, "rtc device register failed!\n");
 299                 goto err_rtc;
 300         }
 301
 302         return ret;
 303
 304 err_rtc:
 305         sensor_hub_device_close(hsdev);
 306 err_open:
 307         sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TIME);
 308         return ret;
 309 }
 310
 311 static int hid_time_remove(struct platform_device *pdev)
 312 {
 313         struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 314
 315         sensor_hub_device_close(hsdev);
 316         sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TIME);
 317
 318         return 0;
 319 }
 320
 321 static struct platform_device_id hid_time_ids[] = {
 322         {
 323                 /* Format: HID-SENSOR-usage_id_in_hex_lowercase */
 324                 .name = "HID-SENSOR-2000a0",
 325         },
 326         { /* sentinel */ }
 327 };
 328 MODULE_DEVICE_TABLE(platform, hid_time_ids);
 329
 330 static struct platform_driver hid_time_platform_driver = {
 331         .id_table = hid_time_ids,
 332         .driver = {
 333                 .name   = KBUILD_MODNAME,
 334         },
 335         .probe          = hid_time_probe,
 336         .remove         = hid_time_remove,
 337 };
 338 module_platform_driver(hid_time_platform_driver);
 339
 340 MODULE_DESCRIPTION("HID Sensor Time");
 341 MODULE_AUTHOR("Alexander Holler <holler@ahsoftware.de>");
 342 MODULE_LICENSE("GPL");