linux/drivers/rtc/rtc-meson-vrtc.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2019 BayLibre, SAS
   4 * Author: Neil Armstrong <narmstrong@baylibre.com>
   5 * Copyright (C) 2015 Amlogic, Inc. All rights reserved.
   6 */
   7#include <linux/module.h>
   8#include <linux/platform_device.h>
   9#include <linux/rtc.h>
  10#include <linux/io.h>
  11#include <linux/of.h>
  12#include <linux/time64.h>
  13
  14struct meson_vrtc_data {
  15        void __iomem *io_alarm;
  16        struct rtc_device *rtc;
  17        unsigned long alarm_time;
  18        bool enabled;
  19};
  20
  21static int meson_vrtc_read_time(struct device *dev, struct rtc_time *tm)
  22{
  23        struct timespec64 time;
  24
  25        dev_dbg(dev, "%s\n", __func__);
  26        ktime_get_raw_ts64(&time);
  27        rtc_time64_to_tm(time.tv_sec, tm);
  28
  29        return 0;
  30}
  31
  32static void meson_vrtc_set_wakeup_time(struct meson_vrtc_data *vrtc,
  33                                       unsigned long time)
  34{
  35        writel_relaxed(time, vrtc->io_alarm);
  36}
  37
  38static int meson_vrtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
  39{
  40        struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
  41
  42        dev_dbg(dev, "%s: alarm->enabled=%d\n", __func__, alarm->enabled);
  43        if (alarm->enabled)
  44                vrtc->alarm_time = rtc_tm_to_time64(&alarm->time);
  45        else
  46                vrtc->alarm_time = 0;
  47
  48        return 0;
  49}
  50
  51static int meson_vrtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
  52{
  53        struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
  54
  55        vrtc->enabled = enabled;
  56        return 0;
  57}
  58
  59static const struct rtc_class_ops meson_vrtc_ops = {
  60        .read_time = meson_vrtc_read_time,
  61        .set_alarm = meson_vrtc_set_alarm,
  62        .alarm_irq_enable = meson_vrtc_alarm_irq_enable,
  63};
  64
  65static int meson_vrtc_probe(struct platform_device *pdev)
  66{
  67        struct meson_vrtc_data *vrtc;
  68
  69        vrtc = devm_kzalloc(&pdev->dev, sizeof(*vrtc), GFP_KERNEL);
  70        if (!vrtc)
  71                return -ENOMEM;
  72
  73        vrtc->io_alarm = devm_platform_ioremap_resource(pdev, 0);
  74        if (IS_ERR(vrtc->io_alarm))
  75                return PTR_ERR(vrtc->io_alarm);
  76
  77        device_init_wakeup(&pdev->dev, 1);
  78
  79        platform_set_drvdata(pdev, vrtc);
  80
  81        vrtc->rtc = devm_rtc_allocate_device(&pdev->dev);
  82        if (IS_ERR(vrtc->rtc))
  83                return PTR_ERR(vrtc->rtc);
  84
  85        vrtc->rtc->ops = &meson_vrtc_ops;
  86        return devm_rtc_register_device(vrtc->rtc);
  87}
  88
  89static int __maybe_unused meson_vrtc_suspend(struct device *dev)
  90{
  91        struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
  92
  93        dev_dbg(dev, "%s\n", __func__);
  94        if (vrtc->alarm_time) {
  95                unsigned long local_time;
  96                long alarm_secs;
  97                struct timespec64 time;
  98
  99                ktime_get_raw_ts64(&time);
 100                local_time = time.tv_sec;
 101
 102                dev_dbg(dev, "alarm_time = %lus, local_time=%lus\n",
 103                        vrtc->alarm_time, local_time);
 104                alarm_secs = vrtc->alarm_time - local_time;
 105                if (alarm_secs > 0) {
 106                        meson_vrtc_set_wakeup_time(vrtc, alarm_secs);
 107                        dev_dbg(dev, "system will wakeup in %lds.\n",
 108                                alarm_secs);
 109                } else {
 110                        dev_err(dev, "alarm time already passed: %lds.\n",
 111                                alarm_secs);
 112                }
 113        }
 114
 115        return 0;
 116}
 117
 118static int __maybe_unused meson_vrtc_resume(struct device *dev)
 119{
 120        struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
 121
 122        dev_dbg(dev, "%s\n", __func__);
 123
 124        vrtc->alarm_time = 0;
 125        meson_vrtc_set_wakeup_time(vrtc, 0);
 126        return 0;
 127}
 128
 129static SIMPLE_DEV_PM_OPS(meson_vrtc_pm_ops,
 130                         meson_vrtc_suspend, meson_vrtc_resume);
 131
 132static const struct of_device_id meson_vrtc_dt_match[] = {
 133        { .compatible = "amlogic,meson-vrtc"},
 134        {},
 135};
 136MODULE_DEVICE_TABLE(of, meson_vrtc_dt_match);
 137
 138static struct platform_driver meson_vrtc_driver = {
 139        .probe = meson_vrtc_probe,
 140        .driver = {
 141                .name = "meson-vrtc",
 142                .of_match_table = meson_vrtc_dt_match,
 143                .pm = &meson_vrtc_pm_ops,
 144        },
 145};
 146
 147module_platform_driver(meson_vrtc_driver);
 148
 149MODULE_DESCRIPTION("Amlogic Virtual Wakeup RTC Timer driver");
 150MODULE_LICENSE("GPL");
 151