linux/drivers/rtc/rtc-test.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * An RTC test device/driver
   4 * Copyright (C) 2005 Tower Technologies
   5 * Author: Alessandro Zummo <a.zummo@towertech.it>
   6 */
   7
   8#include <linux/module.h>
   9#include <linux/err.h>
  10#include <linux/rtc.h>
  11#include <linux/platform_device.h>
  12
  13#define MAX_RTC_TEST 3
  14
  15struct rtc_test_data {
  16        struct rtc_device *rtc;
  17        time64_t offset;
  18        struct timer_list alarm;
  19        bool alarm_en;
  20};
  21
  22static struct platform_device *pdev[MAX_RTC_TEST];
  23
  24static int test_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  25{
  26        struct rtc_test_data *rtd = dev_get_drvdata(dev);
  27        time64_t alarm;
  28
  29        alarm = (rtd->alarm.expires - jiffies) / HZ;
  30        alarm += ktime_get_real_seconds() + rtd->offset;
  31
  32        rtc_time64_to_tm(alarm, &alrm->time);
  33        alrm->enabled = rtd->alarm_en;
  34
  35        return 0;
  36}
  37
  38static int test_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  39{
  40        struct rtc_test_data *rtd = dev_get_drvdata(dev);
  41        ktime_t timeout;
  42        u64 expires;
  43
  44        timeout = rtc_tm_to_time64(&alrm->time) - ktime_get_real_seconds();
  45        timeout -= rtd->offset;
  46
  47        del_timer(&rtd->alarm);
  48
  49        expires = jiffies + timeout * HZ;
  50        if (expires > U32_MAX)
  51                expires = U32_MAX;
  52
  53        rtd->alarm.expires = expires;
  54
  55        if (alrm->enabled)
  56                add_timer(&rtd->alarm);
  57
  58        rtd->alarm_en = alrm->enabled;
  59
  60        return 0;
  61}
  62
  63static int test_rtc_read_time(struct device *dev, struct rtc_time *tm)
  64{
  65        struct rtc_test_data *rtd = dev_get_drvdata(dev);
  66
  67        rtc_time64_to_tm(ktime_get_real_seconds() + rtd->offset, tm);
  68
  69        return 0;
  70}
  71
  72static int test_rtc_set_time(struct device *dev, struct rtc_time *tm)
  73{
  74        struct rtc_test_data *rtd = dev_get_drvdata(dev);
  75
  76        rtd->offset = rtc_tm_to_time64(tm) - ktime_get_real_seconds();
  77
  78        return 0;
  79}
  80
  81static int test_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
  82{
  83        struct rtc_test_data *rtd = dev_get_drvdata(dev);
  84
  85        rtd->alarm_en = enable;
  86        if (enable)
  87                add_timer(&rtd->alarm);
  88        else
  89                del_timer(&rtd->alarm);
  90
  91        return 0;
  92}
  93
  94static const struct rtc_class_ops test_rtc_ops_noalm = {
  95        .read_time = test_rtc_read_time,
  96        .set_time = test_rtc_set_time,
  97        .alarm_irq_enable = test_rtc_alarm_irq_enable,
  98};
  99
 100static const struct rtc_class_ops test_rtc_ops = {
 101        .read_time = test_rtc_read_time,
 102        .set_time = test_rtc_set_time,
 103        .read_alarm = test_rtc_read_alarm,
 104        .set_alarm = test_rtc_set_alarm,
 105        .alarm_irq_enable = test_rtc_alarm_irq_enable,
 106};
 107
 108static void test_rtc_alarm_handler(struct timer_list *t)
 109{
 110        struct rtc_test_data *rtd = from_timer(rtd, t, alarm);
 111
 112        rtc_update_irq(rtd->rtc, 1, RTC_AF | RTC_IRQF);
 113}
 114
 115static int test_probe(struct platform_device *plat_dev)
 116{
 117        struct rtc_test_data *rtd;
 118
 119        rtd = devm_kzalloc(&plat_dev->dev, sizeof(*rtd), GFP_KERNEL);
 120        if (!rtd)
 121                return -ENOMEM;
 122
 123        platform_set_drvdata(plat_dev, rtd);
 124
 125        rtd->rtc = devm_rtc_allocate_device(&plat_dev->dev);
 126        if (IS_ERR(rtd->rtc))
 127                return PTR_ERR(rtd->rtc);
 128
 129        switch (plat_dev->id) {
 130        case 0:
 131                rtd->rtc->ops = &test_rtc_ops_noalm;
 132                break;
 133        default:
 134                rtd->rtc->ops = &test_rtc_ops;
 135                device_init_wakeup(&plat_dev->dev, 1);
 136        }
 137
 138        timer_setup(&rtd->alarm, test_rtc_alarm_handler, 0);
 139        rtd->alarm.expires = 0;
 140
 141        return devm_rtc_register_device(rtd->rtc);
 142}
 143
 144static struct platform_driver test_driver = {
 145        .probe  = test_probe,
 146        .driver = {
 147                .name = "rtc-test",
 148        },
 149};
 150
 151static int __init test_init(void)
 152{
 153        int i, err;
 154
 155        err = platform_driver_register(&test_driver);
 156        if (err)
 157                return err;
 158
 159        err = -ENOMEM;
 160        for (i = 0; i < MAX_RTC_TEST; i++) {
 161                pdev[i] = platform_device_alloc("rtc-test", i);
 162                if (!pdev[i])
 163                        goto exit_free_mem;
 164        }
 165
 166        for (i = 0; i < MAX_RTC_TEST; i++) {
 167                err = platform_device_add(pdev[i]);
 168                if (err)
 169                        goto exit_device_del;
 170        }
 171
 172        return 0;
 173
 174exit_device_del:
 175        for (; i > 0; i--)
 176                platform_device_del(pdev[i - 1]);
 177
 178exit_free_mem:
 179        for (i = 0; i < MAX_RTC_TEST; i++)
 180                platform_device_put(pdev[i]);
 181
 182        platform_driver_unregister(&test_driver);
 183        return err;
 184}
 185
 186static void __exit test_exit(void)
 187{
 188        int i;
 189
 190        for (i = 0; i < MAX_RTC_TEST; i++)
 191                platform_device_unregister(pdev[i]);
 192
 193        platform_driver_unregister(&test_driver);
 194}
 195
 196MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
 197MODULE_DESCRIPTION("RTC test driver/device");
 198MODULE_LICENSE("GPL v2");
 199
 200module_init(test_init);
 201module_exit(test_exit);
 202