LXR linux/drivers/rtc/rtc-hid-sensor-time.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * HID Sensor Time Driver
   4 * Copyright (c) 2012, Alexander Holler.
   5 */
   6#include <linux/device.h>
   7#include <linux/platform_device.h>
   8#include <linux/module.h>
   9#include <linux/hid-sensor-hub.h>
  10#include <linux/iio/iio.h>
  11#include <linux/rtc.h>
  12
  13enum hid_time_channel {
  14        CHANNEL_SCAN_INDEX_YEAR,
  15        CHANNEL_SCAN_INDEX_MONTH,
  16        CHANNEL_SCAN_INDEX_DAY,
  17        CHANNEL_SCAN_INDEX_HOUR,
  18        CHANNEL_SCAN_INDEX_MINUTE,
  19        CHANNEL_SCAN_INDEX_SECOND,
  20        TIME_RTC_CHANNEL_MAX,
  21};
  22
  23struct hid_time_state {
  24        struct hid_sensor_hub_callbacks callbacks;
  25        struct hid_sensor_common common_attributes;
  26        struct hid_sensor_hub_attribute_info info[TIME_RTC_CHANNEL_MAX];
  27        struct rtc_time last_time;
  28        spinlock_t lock_last_time;
  29        struct completion comp_last_time;
  30        struct rtc_time time_buf;
  31        struct rtc_device *rtc;
  32};
  33
  34static const u32 hid_time_addresses[TIME_RTC_CHANNEL_MAX] = {
  35        HID_USAGE_SENSOR_TIME_YEAR,
  36        HID_USAGE_SENSOR_TIME_MONTH,
  37        HID_USAGE_SENSOR_TIME_DAY,
  38        HID_USAGE_SENSOR_TIME_HOUR,
  39        HID_USAGE_SENSOR_TIME_MINUTE,
  40        HID_USAGE_SENSOR_TIME_SECOND,
  41};
  42
  43/* Channel names for verbose error messages */
  44static const char * const hid_time_channel_names[TIME_RTC_CHANNEL_MAX] = {
  45        "year", "month", "day", "hour", "minute", "second",
  46};
  47
  48/* Callback handler to send event after all samples are received and captured */
  49static int hid_time_proc_event(struct hid_sensor_hub_device *hsdev,
  50                                unsigned usage_id, void *priv)
  51{
  52        unsigned long flags;
  53        struct hid_time_state *time_state = platform_get_drvdata(priv);
  54
  55        spin_lock_irqsave(&time_state->lock_last_time, flags);
  56        time_state->last_time = time_state->time_buf;
  57        spin_unlock_irqrestore(&time_state->lock_last_time, flags);
  58        complete(&time_state->comp_last_time);
  59        return 0;
  60}
  61
  62static u32 hid_time_value(size_t raw_len, char *raw_data)
  63{
  64        switch (raw_len) {
  65        case 1:
  66                return *(u8 *)raw_data;
  67        case 2:
  68                return *(u16 *)raw_data;
  69        case 4:
  70                return *(u32 *)raw_data;
  71        default:
  72                return (u32)(~0U); /* 0xff... or -1 to denote an error */
  73        }
  74}
  75
  76static int hid_time_capture_sample(struct hid_sensor_hub_device *hsdev,
  77                                unsigned usage_id, size_t raw_len,
  78                                char *raw_data, void *priv)
  79{
  80        struct hid_time_state *time_state = platform_get_drvdata(priv);
  81        struct rtc_time *time_buf = &time_state->time_buf;
  82
  83        switch (usage_id) {
  84        case HID_USAGE_SENSOR_TIME_YEAR:
  85                /*
  86                 * The draft for HID-sensors (HUTRR39) currently doesn't define
  87                 * the range for the year attribute. Therefor we support
  88                 * 8 bit (0-99) and 16 or 32 bits (full) as size for the year.
  89                 */
  90                if (raw_len == 1) {
  91                        time_buf->tm_year = *(u8 *)raw_data;
  92                        if (time_buf->tm_year < 70)
  93                                /* assume we are in 1970...2069 */
  94                                time_buf->tm_year += 100;
  95                } else
  96                        time_buf->tm_year =
  97                                (int)hid_time_value(raw_len, raw_data)-1900;
  98                break;
  99        case HID_USAGE_SENSOR_TIME_MONTH:
 100                /* sensors are sending the month as 1-12, we need 0-11 */
 101                time_buf->tm_mon = (int)hid_time_value(raw_len, raw_data)-1;
 102                break;
 103        case HID_USAGE_SENSOR_TIME_DAY:
 104                time_buf->tm_mday = (int)hid_time_value(raw_len, raw_data);
 105                break;
 106        case HID_USAGE_SENSOR_TIME_HOUR:
 107                time_buf->tm_hour = (int)hid_time_value(raw_len, raw_data);
 108                break;
 109        case HID_USAGE_SENSOR_TIME_MINUTE:
 110                time_buf->tm_min = (int)hid_time_value(raw_len, raw_data);
 111                break;
 112        case HID_USAGE_SENSOR_TIME_SECOND:
 113                time_buf->tm_sec = (int)hid_time_value(raw_len, raw_data);
 114                break;
 115        default:
 116                return -EINVAL;
 117        }
 118        return 0;
 119}
 120
 121/* small helper, haven't found any other way */
 122static const char *hid_time_attrib_name(u32 attrib_id)
 123{
 124        static const char unknown[] = "unknown";
 125        unsigned i;
 126
 127        for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i) {
 128                if (hid_time_addresses[i] == attrib_id)
 129                        return hid_time_channel_names[i];
 130        }
 131        return unknown; /* should never happen */
 132}
 133
 134static int hid_time_parse_report(struct platform_device *pdev,
 135                                struct hid_sensor_hub_device *hsdev,
 136                                unsigned usage_id,
 137                                struct hid_time_state *time_state)
 138{
 139        int report_id, i;
 140
 141        for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i)
 142                if (sensor_hub_input_get_attribute_info(hsdev,
 143                                HID_INPUT_REPORT, usage_id,
 144                                hid_time_addresses[i],
 145                                &time_state->info[i]) < 0)
 146                        return -EINVAL;
 147        /* Check the (needed) attributes for sanity */
 148        report_id = time_state->info[0].report_id;
 149        if (report_id < 0) {
 150                dev_err(&pdev->dev, "bad report ID!\n");
 151                return -EINVAL;
 152        }
 153        for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i) {
 154                if (time_state->info[i].report_id != report_id) {
 155                        dev_err(&pdev->dev,
 156                                "not all needed attributes inside the same report!\n");
 157                        return -EINVAL;
 158                }
 159                if (time_state->info[i].size == 3 ||
 160                                time_state->info[i].size > 4) {
 161                        dev_err(&pdev->dev,
 162                                "attribute '%s' not 8, 16 or 32 bits wide!\n",
 163                                hid_time_attrib_name(
 164                                        time_state->info[i].attrib_id));
 165                        return -EINVAL;
 166                }
 167                if (time_state->info[i].units !=
 168                                HID_USAGE_SENSOR_UNITS_NOT_SPECIFIED &&
 169                                /* allow attribute seconds with unit seconds */
 170                                !(time_state->info[i].attrib_id ==
 171                                HID_USAGE_SENSOR_TIME_SECOND &&
 172                                time_state->info[i].units ==
 173                                HID_USAGE_SENSOR_UNITS_SECOND)) {
 174                        dev_err(&pdev->dev,
 175                                "attribute '%s' hasn't a unit of type 'none'!\n",
 176                                hid_time_attrib_name(
 177                                        time_state->info[i].attrib_id));
 178                        return -EINVAL;
 179                }
 180                if (time_state->info[i].unit_expo) {
 181                        dev_err(&pdev->dev,
 182                                "attribute '%s' hasn't a unit exponent of 1!\n",
 183                                hid_time_attrib_name(
 184                                        time_state->info[i].attrib_id));
 185                        return -EINVAL;
 186                }
 187        }
 188
 189        return 0;
 190}
 191
 192static int hid_rtc_read_time(struct device *dev, struct rtc_time *tm)
 193{
 194        unsigned long flags;
 195        struct hid_time_state *time_state = dev_get_drvdata(dev);
 196        int ret;
 197
 198        reinit_completion(&time_state->comp_last_time);
 199        /* get a report with all values through requesting one value */
 200        sensor_hub_input_attr_get_raw_value(time_state->common_attributes.hsdev,
 201                        HID_USAGE_SENSOR_TIME, hid_time_addresses[0],
 202                        time_state->info[0].report_id, SENSOR_HUB_SYNC, false);
 203        /* wait for all values (event) */
 204        ret = wait_for_completion_killable_timeout(
 205                        &time_state->comp_last_time, HZ*6);
 206        if (ret > 0) {
 207                /* no error */
 208                spin_lock_irqsave(&time_state->lock_last_time, flags);
 209                *tm = time_state->last_time;
 210                spin_unlock_irqrestore(&time_state->lock_last_time, flags);
 211                return 0;
 212        }
 213        if (!ret)
 214                return -EIO; /* timeouted */
 215        return ret; /* killed (-ERESTARTSYS) */
 216}
 217
 218static const struct rtc_class_ops hid_time_rtc_ops = {
 219        .read_time = hid_rtc_read_time,
 220};
 221
 222static int hid_time_probe(struct platform_device *pdev)
 223{
 224        int ret = 0;
 225        struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 226        struct hid_time_state *time_state = devm_kzalloc(&pdev->dev,
 227                sizeof(struct hid_time_state), GFP_KERNEL);
 228
 229        if (time_state == NULL)
 230                return -ENOMEM;
 231
 232        platform_set_drvdata(pdev, time_state);
 233
 234        spin_lock_init(&time_state->lock_last_time);
 235        init_completion(&time_state->comp_last_time);
 236        time_state->common_attributes.hsdev = hsdev;
 237        time_state->common_attributes.pdev = pdev;
 238
 239        ret = hid_sensor_parse_common_attributes(hsdev,
 240                                HID_USAGE_SENSOR_TIME,
 241                                &time_state->common_attributes);
 242        if (ret) {
 243                dev_err(&pdev->dev, "failed to setup common attributes!\n");
 244                return ret;
 245        }
 246
 247        ret = hid_time_parse_report(pdev, hsdev, HID_USAGE_SENSOR_TIME,
 248                                        time_state);
 249        if (ret) {
 250                dev_err(&pdev->dev, "failed to setup attributes!\n");
 251                return ret;
 252        }
 253
 254        time_state->callbacks.send_event = hid_time_proc_event;
 255        time_state->callbacks.capture_sample = hid_time_capture_sample;
 256        time_state->callbacks.pdev = pdev;
 257        ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_TIME,
 258                                        &time_state->callbacks);
 259        if (ret < 0) {
 260                dev_err(&pdev->dev, "register callback failed!\n");
 261                return ret;
 262        }
 263
 264        ret = sensor_hub_device_open(hsdev);
 265        if (ret) {
 266                dev_err(&pdev->dev, "failed to open sensor hub device!\n");
 267                goto err_open;
 268        }
 269
 270        /*
 271         * Enable HID input processing early in order to be able to read the
 272         * clock already in devm_rtc_device_register().
 273         */
 274        hid_device_io_start(hsdev->hdev);
 275
 276        time_state->rtc = devm_rtc_device_register(&pdev->dev,
 277                                        "hid-sensor-time", &hid_time_rtc_ops,
 278                                        THIS_MODULE);
 279
 280        if (IS_ERR(time_state->rtc)) {
 281                hid_device_io_stop(hsdev->hdev);
 282                ret = PTR_ERR(time_state->rtc);
 283                time_state->rtc = NULL;
 284                dev_err(&pdev->dev, "rtc device register failed!\n");
 285                goto err_rtc;
 286        }
 287
 288        return ret;
 289
 290err_rtc:
 291        sensor_hub_device_close(hsdev);
 292err_open:
 293        sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TIME);
 294        return ret;
 295}
 296
 297static int hid_time_remove(struct platform_device *pdev)
 298{
 299        struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
 300
 301        sensor_hub_device_close(hsdev);
 302        sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TIME);
 303
 304        return 0;
 305}
 306
 307static const struct platform_device_id hid_time_ids[] = {
 308        {
 309                /* Format: HID-SENSOR-usage_id_in_hex_lowercase */
 310                .name = "HID-SENSOR-2000a0",
 311        },
 312        { /* sentinel */ }
 313};
 314MODULE_DEVICE_TABLE(platform, hid_time_ids);
 315
 316static struct platform_driver hid_time_platform_driver = {
 317        .id_table = hid_time_ids,
 318        .driver = {
 319                .name   = KBUILD_MODNAME,
 320        },
 321        .probe          = hid_time_probe,
 322        .remove         = hid_time_remove,
 323};
 324module_platform_driver(hid_time_platform_driver);
 325
 326MODULE_DESCRIPTION("HID Sensor Time");
 327MODULE_AUTHOR("Alexander Holler <holler@ahsoftware.de>");
 328MODULE_LICENSE("GPL");
 329