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
  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
  30enum 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
  40struct 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
  51static 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 */
  61static 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 */
  66static 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
  79static 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
  93static 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 */
 139static 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
 151static 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
 209static 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
 236static const struct rtc_class_ops hid_time_rtc_ops = {
 237        .read_time = hid_rtc_read_time,
 238};
 239
 240static 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
 294static 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
 303static 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};
 311module_platform_driver(hid_time_platform_driver);
 312
 313MODULE_DESCRIPTION("HID Sensor Time");
 314MODULE_AUTHOR("Alexander Holler <holler@ahsoftware.de>");
 315MODULE_LICENSE("GPL");
 316
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