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 /* Format: HID-SENSOR-usage_id_in_hex */
  27 /* Usage ID from spec for Time: 0x2000A0 */
  28 #define DRIVER_NAME "HID-SENSOR-2000a0" /* must be lowercase */
  29
  30 enum hid_time_channel {
  31         CHANNEL_SCAN_INDEX_YEAR,
  32         CHANNEL_SCAN_INDEX_MONTH,
  33         CHANNEL_SCAN_INDEX_DAY,
  34         CHANNEL_SCAN_INDEX_HOUR,
  35         CHANNEL_SCAN_INDEX_MINUTE,
  36         CHANNEL_SCAN_INDEX_SECOND,
  37         TIME_RTC_CHANNEL_MAX,
  38 };
  39
  40 struct hid_time_state {
  41         struct hid_sensor_hub_callbacks callbacks;
  42         struct hid_sensor_common common_attributes;
  43         struct hid_sensor_hub_attribute_info info[TIME_RTC_CHANNEL_MAX];
  44         struct rtc_time last_time;
  45         spinlock_t lock_last_time;
  46         struct completion comp_last_time;
  47         struct rtc_time time_buf;
  48         struct rtc_device *rtc;
  49 };
  50
  51 static const u32 hid_time_addresses[TIME_RTC_CHANNEL_MAX] = {
  52         HID_USAGE_SENSOR_TIME_YEAR,
  53         HID_USAGE_SENSOR_TIME_MONTH,
  54         HID_USAGE_SENSOR_TIME_DAY,
  55         HID_USAGE_SENSOR_TIME_HOUR,
  56         HID_USAGE_SENSOR_TIME_MINUTE,
  57         HID_USAGE_SENSOR_TIME_SECOND,
  58 };
  59
  60 /* Channel names for verbose error messages */
  61 static const char * const hid_time_channel_names[TIME_RTC_CHANNEL_MAX] = {
  62         "year", "month", "day", "hour", "minute", "second",
  63 };
  64
  65 /* Callback handler to send event after all samples are received and captured */
  66 static int hid_time_proc_event(struct hid_sensor_hub_device *hsdev,
  67                                 unsigned usage_id, void *priv)
  68 {
  69         unsigned long flags;
  70         struct hid_time_state *time_state = platform_get_drvdata(priv);
  71
  72         spin_lock_irqsave(&time_state->lock_last_time, flags);
  73         time_state->last_time = time_state->time_buf;
  74         spin_unlock_irqrestore(&time_state->lock_last_time, flags);
  75         complete(&time_state->comp_last_time);
  76         return 0;
  77 }
  78
  79 static u32 hid_time_value(size_t raw_len, char *raw_data)
  80 {
  81         switch (raw_len) {
  82         case 1:
  83                 return *(u8 *)raw_data;
  84         case 2:
  85                 return *(u16 *)raw_data;
  86         case 4:
  87                 return *(u32 *)raw_data;
  88         default:
  89                 return (u32)(~0U); /* 0xff... or -1 to denote an error */
  90         }
  91 }
  92
  93 static int hid_time_capture_sample(struct hid_sensor_hub_device *hsdev,
  94                                 unsigned usage_id, size_t raw_len,
  95                                 char *raw_data, void *priv)
  96 {
  97         struct hid_time_state *time_state = platform_get_drvdata(priv);
  98         struct rtc_time *time_buf = &time_state->time_buf;
  99
 100         switch (usage_id) {
 101         case HID_USAGE_SENSOR_TIME_YEAR:
 102                 /*
 103                  * The draft for HID-sensors (HUTRR39) currently doesn't define
 104                  * the range for the year attribute. Therefor we support
 105                  * 8 bit (0-99) and 16 or 32 bits (full) as size for the year.
 106                  */
 107                 if (raw_len == 1) {
 108                         time_buf->tm_year = *(u8 *)raw_data;
 109                         if (time_buf->tm_year < 70)
 110                                 /* assume we are in 1970...2069 */
 111                                 time_buf->tm_year += 100;
 112                 } else
 113                         time_buf->tm_year =
 114                                 (int)hid_time_value(raw_len, raw_data)-1900;
 115                 break;
 116         case HID_USAGE_SENSOR_TIME_MONTH:
 117                 /* sensors are sending the month as 1-12, we need 0-11 */
 118                 time_buf->tm_mon = (int)hid_time_value(raw_len, raw_data)-1;
 119                 break;
 120         case HID_USAGE_SENSOR_TIME_DAY:
 121                 time_buf->tm_mday = (int)hid_time_value(raw_len, raw_data);
 122                 break;
 123         case HID_USAGE_SENSOR_TIME_HOUR:
 124                 time_buf->tm_hour = (int)hid_time_value(raw_len, raw_data);
 125                 break;
 126         case HID_USAGE_SENSOR_TIME_MINUTE:
 127                 time_buf->tm_min = (int)hid_time_value(raw_len, raw_data);
 128                 break;
 129         case HID_USAGE_SENSOR_TIME_SECOND:
 130                 time_buf->tm_sec = (int)hid_time_value(raw_len, raw_data);
 131                 break;
 132         default:
 133                 return -EINVAL;
 134         }
 135         return 0;
 136 }
 137
 138 /* small helper, haven't found any other way */
 139 static const char *hid_time_attrib_name(u32 attrib_id)
 140 {
 141         static const char unknown[] = "unknown";
 142         unsigned i;
 143
 144         for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i) {
 145                 if (hid_time_addresses[i] == attrib_id)
 146                         return hid_time_channel_names[i];
 147         }
 148         return unknown; /* should never happen */
 149 }
 150
 151 static int hid_time_parse_report(struct platform_device *pdev,
 152                                 struct hid_sensor_hub_device *hsdev,
 153                                 unsigned usage_id,
 154                                 struct hid_time_state *time_state)
 155 {
 156         int report_id, i;
 157
 158         for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i)
 159                 if (sensor_hub_input_get_attribute_info(hsdev,
 160                                 HID_INPUT_REPORT, usage_id,
 161                                 hid_time_addresses[i],
 162                                 &time_state->info[i]) < 0)
 163                         return -EINVAL;
 164         /* Check the (needed) attributes for sanity */
 165         report_id = time_state->info[0].report_id;
 166         if (report_id < 0) {
 167                 dev_err(&pdev->dev, "bad report ID!\n");
 168                 return -EINVAL;
 169         }
 170         for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i) {
 171                 if (time_state->info[i].report_id != report_id) {
 172                         dev_err(&pdev->dev,
 173                                 "not all needed attributes inside the same report!\n");
 174                         return -EINVAL;
 175                 }
 176                 if (time_state->info[i].size == 3 ||
 177                                 time_state->info[i].size > 4) {
 178                         dev_err(&pdev->dev,
 179                                 "attribute '%s' not 8, 16 or 32 bits wide!\n",
 180                                 hid_time_attrib_name(
 181                                         time_state->info[i].attrib_id));
 182                         return -EINVAL;
 183                 }
 184                 if (time_state->info[i].units !=
 185                                 HID_USAGE_SENSOR_UNITS_NOT_SPECIFIED &&
 186                                 /* allow attribute seconds with unit seconds */
 187                                 !(time_state->info[i].attrib_id ==
 188                                 HID_USAGE_SENSOR_TIME_SECOND &&
 189                                 time_state->info[i].units ==
 190                                 HID_USAGE_SENSOR_UNITS_SECOND)) {
 191                         dev_err(&pdev->dev,
 192                                 "attribute '%s' hasn't a unit of type 'none'!\n",
 193                                 hid_time_attrib_name(
 194                                         time_state->info[i].attrib_id));
 195                         return -EINVAL;
 196                 }
 197                 if (time_state->info[i].unit_expo) {
 198                         dev_err(&pdev->dev,
 199                                 "attribute '%s' hasn't a unit exponent of 1!\n",
 200                                 hid_time_attrib_name(
 201                                         time_state->info[i].attrib_id));
 202                         return -EINVAL;
 203                 }
 204         }
 205
 206         return 0;
 207 }
 208
 209 static int hid_rtc_read_time(struct device *dev, struct rtc_time *tm)
 210 {
 211         unsigned long flags;
 212         struct hid_time_state *time_state =
 213                 platform_get_drvdata(to_platform_device(dev));
 214         int ret;
 215
 216         INIT_COMPLETION(time_state->comp_last_time);
 217         /* get a report with all values through requesting one value */
 218         sensor_hub_input_attr_get_raw_value(time_state->common_attributes.hsdev,
 219                         HID_USAGE_SENSOR_TIME, hid_time_addresses[0],
 220                         time_state->info[0].report_id);
 221         /* wait for all values (event) */
 222         ret = wait_for_completion_killable_timeout(
 223                         &time_state->comp_last_time, HZ*6);
 224         if (ret > 0) {
 225                 /* no error */
 226                 spin_lock_irqsave(&time_state->lock_last_time, flags);
 227                 *tm = time_state->last_time;
 228                 spin_unlock_irqrestore(&time_state->lock_last_time, flags);
 229                 return 0;
 230         }
 231         if (!ret)
 232                 return -EIO; /* timeouted */
 233         return ret; /* killed (-ERESTARTSYS) */
 234 }
 235
 236 static const struct rtc_class_ops hid_time_rtc_ops = {
 237         .read_time = hid_rtc_read_time,
 238 };
 239
 240 static int hid_time_probe(struct platform_device *pdev)
 241 {
 242         int ret = 0;
 243         struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
 244         struct hid_time_state *time_state = devm_kzalloc(&pdev->dev,
 245                 sizeof(struct hid_time_state), GFP_KERNEL);
 246
 247         if (time_state == NULL)
 248                 return -ENOMEM;
 249
 250         platform_set_drvdata(pdev, time_state);
 251
 252         spin_lock_init(&time_state->lock_last_time);
 253         init_completion(&time_state->comp_last_time);
 254         time_state->common_attributes.hsdev = hsdev;
 255         time_state->common_attributes.pdev = pdev;
 256
 257         ret = hid_sensor_parse_common_attributes(hsdev,
 258                                 HID_USAGE_SENSOR_TIME,
 259                                 &time_state->common_attributes);
 260         if (ret) {
 261                 dev_err(&pdev->dev, "failed to setup common attributes!\n");
 262                 return ret;
 263         }
 264
 265         ret = hid_time_parse_report(pdev, hsdev, HID_USAGE_SENSOR_TIME,
 266                                         time_state);
 267         if (ret) {
 268                 dev_err(&pdev->dev, "failed to setup attributes!\n");
 269                 return ret;
 270         }
 271
 272         time_state->callbacks.send_event = hid_time_proc_event;
 273         time_state->callbacks.capture_sample = hid_time_capture_sample;
 274         time_state->callbacks.pdev = pdev;
 275         ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_TIME,
 276                                         &time_state->callbacks);
 277         if (ret < 0) {
 278                 dev_err(&pdev->dev, "register callback failed!\n");
 279                 return ret;
 280         }
 281
 282         time_state->rtc = devm_rtc_device_register(&pdev->dev,
 283                                         "hid-sensor-time", &hid_time_rtc_ops,
 284                                         THIS_MODULE);
 285
 286         if (IS_ERR(time_state->rtc)) {
 287                 dev_err(&pdev->dev, "rtc device register failed!\n");
 288                 return PTR_ERR(time_state->rtc);
 289         }
 290
 291         return ret;
 292 }
 293
 294 static int hid_time_remove(struct platform_device *pdev)
 295 {
 296         struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
 297
 298         sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TIME);
 299
 300         return 0;
 301 }
 302
 303 static struct platform_driver hid_time_platform_driver = {
 304         .driver = {
 305                 .name   = DRIVER_NAME,
 306                 .owner  = THIS_MODULE,
 307         },
 308         .probe          = hid_time_probe,
 309         .remove         = hid_time_remove,
 310 };
 311 module_platform_driver(hid_time_platform_driver);
 312
 313 MODULE_DESCRIPTION("HID Sensor Time");
 314 MODULE_AUTHOR("Alexander Holler <holler@ahsoftware.de>");
 315 MODULE_LICENSE("GPL");