linux/drivers/rtc/rtc-hid-sensor-time.c
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   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
  26enum 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
  36struct 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
  47static 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 */
  57static 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 */
  62static 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
  75static 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
  89static 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 */
 135static 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
 147static 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
 205static 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        INIT_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);
 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
 232static const struct rtc_class_ops hid_time_rtc_ops = {
 233        .read_time = hid_rtc_read_time,
 234};
 235
 236static int hid_time_probe(struct platform_device *pdev)
 237{
 238        int ret = 0;
 239        struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
 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        time_state->rtc = devm_rtc_device_register(&pdev->dev,
 279                                        "hid-sensor-time", &hid_time_rtc_ops,
 280                                        THIS_MODULE);
 281
 282        if (IS_ERR_OR_NULL(time_state->rtc)) {
 283                ret = time_state->rtc ? PTR_ERR(time_state->rtc) : -ENODEV;
 284                time_state->rtc = NULL;
 285                sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TIME);
 286                dev_err(&pdev->dev, "rtc device register failed!\n");
 287        }
 288
 289        return ret;
 290}
 291
 292static int hid_time_remove(struct platform_device *pdev)
 293{
 294        struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
 295
 296        sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TIME);
 297
 298        return 0;
 299}
 300
 301static struct platform_device_id hid_time_ids[] = {
 302        {
 303                /* Format: HID-SENSOR-usage_id_in_hex_lowercase */
 304                .name = "HID-SENSOR-2000a0",
 305        },
 306        { /* sentinel */ }
 307};
 308MODULE_DEVICE_TABLE(platform, hid_time_ids);
 309
 310static struct platform_driver hid_time_platform_driver = {
 311        .id_table = hid_time_ids,
 312        .driver = {
 313                .name   = KBUILD_MODNAME,
 314                .owner  = THIS_MODULE,
 315        },
 316        .probe          = hid_time_probe,
 317        .remove         = hid_time_remove,
 318};
 319module_platform_driver(hid_time_platform_driver);
 320
 321MODULE_DESCRIPTION("HID Sensor Time");
 322MODULE_AUTHOR("Alexander Holler <holler@ahsoftware.de>");
 323MODULE_LICENSE("GPL");
 324
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