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