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