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 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 */
 116static 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
 128static 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
 185static 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
 212static const struct rtc_class_ops hid_time_rtc_ops = {
 213        .read_time = hid_rtc_read_time,
 214};
 215
 216static 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 = rtc_device_register("hid-sensor-time",
 259                                &pdev->dev, &hid_time_rtc_ops, THIS_MODULE);
 260
 261        if (IS_ERR(time_state->rtc)) {
 262                dev_err(&pdev->dev, "rtc device register failed!\n");
 263                return PTR_ERR(time_state->rtc);
 264        }
 265
 266        return ret;
 267}
 268
 269static int hid_time_remove(struct platform_device *pdev)
 270{
 271        struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
 272        struct hid_time_state *time_state = platform_get_drvdata(pdev);
 273
 274        rtc_device_unregister(time_state->rtc);
 275        sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TIME);
 276
 277        return 0;
 278}
 279
 280static struct platform_driver hid_time_platform_driver = {
 281        .driver = {
 282                .name   = DRIVER_NAME,
 283                .owner  = THIS_MODULE,
 284        },
 285        .probe          = hid_time_probe,
 286        .remove         = hid_time_remove,
 287};
 288module_platform_driver(hid_time_platform_driver);
 289
 290MODULE_DESCRIPTION("HID Sensor Time");
 291MODULE_AUTHOR("Alexander Holler <holler@ahsoftware.de>");
 292MODULE_LICENSE("GPL");
 293
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