drivers/rtc/rtc-meson-vrtc.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Copyright (C) 2019 BayLibre, SAS
0004  * Author: Neil Armstrong <narmstrong@baylibre.com>
0005  * Copyright (C) 2015 Amlogic, Inc. All rights reserved.
0006  */
0007 #include <linux/module.h>
0008 #include <linux/platform_device.h>
0009 #include <linux/rtc.h>
0010 #include <linux/io.h>
0011 #include <linux/of.h>
0012 #include <linux/time64.h>
0013
0014 struct meson_vrtc_data {
0015     void __iomem *io_alarm;
0016     struct rtc_device *rtc;
0017     unsigned long alarm_time;
0018     bool enabled;
0019 };
0020
0021 static int meson_vrtc_read_time(struct device *dev, struct rtc_time *tm)
0022 {
0023     struct timespec64 time;
0024
0025     dev_dbg(dev, "%s\n", __func__);
0026     ktime_get_raw_ts64(&time);
0027     rtc_time64_to_tm(time.tv_sec, tm);
0028
0029     return 0;
0030 }
0031
0032 static void meson_vrtc_set_wakeup_time(struct meson_vrtc_data *vrtc,
0033                        unsigned long time)
0034 {
0035     writel_relaxed(time, vrtc->io_alarm);
0036 }
0037
0038 static int meson_vrtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
0039 {
0040     struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
0041
0042     dev_dbg(dev, "%s: alarm->enabled=%d\n", __func__, alarm->enabled);
0043     if (alarm->enabled)
0044         vrtc->alarm_time = rtc_tm_to_time64(&alarm->time);
0045     else
0046         vrtc->alarm_time = 0;
0047
0048     return 0;
0049 }
0050
0051 static int meson_vrtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
0052 {
0053     struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
0054
0055     vrtc->enabled = enabled;
0056     return 0;
0057 }
0058
0059 static const struct rtc_class_ops meson_vrtc_ops = {
0060     .read_time = meson_vrtc_read_time,
0061     .set_alarm = meson_vrtc_set_alarm,
0062     .alarm_irq_enable = meson_vrtc_alarm_irq_enable,
0063 };
0064
0065 static int meson_vrtc_probe(struct platform_device *pdev)
0066 {
0067     struct meson_vrtc_data *vrtc;
0068
0069     vrtc = devm_kzalloc(&pdev->dev, sizeof(*vrtc), GFP_KERNEL);
0070     if (!vrtc)
0071         return -ENOMEM;
0072
0073     vrtc->io_alarm = devm_platform_ioremap_resource(pdev, 0);
0074     if (IS_ERR(vrtc->io_alarm))
0075         return PTR_ERR(vrtc->io_alarm);
0076
0077     device_init_wakeup(&pdev->dev, 1);
0078
0079     platform_set_drvdata(pdev, vrtc);
0080
0081     vrtc->rtc = devm_rtc_allocate_device(&pdev->dev);
0082     if (IS_ERR(vrtc->rtc))
0083         return PTR_ERR(vrtc->rtc);
0084
0085     vrtc->rtc->ops = &meson_vrtc_ops;
0086     return devm_rtc_register_device(vrtc->rtc);
0087 }
0088
0089 static int __maybe_unused meson_vrtc_suspend(struct device *dev)
0090 {
0091     struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
0092
0093     dev_dbg(dev, "%s\n", __func__);
0094     if (vrtc->alarm_time) {
0095         unsigned long local_time;
0096         long alarm_secs;
0097         struct timespec64 time;
0098
0099         ktime_get_raw_ts64(&time);
0100         local_time = time.tv_sec;
0101
0102         dev_dbg(dev, "alarm_time = %lus, local_time=%lus\n",
0103             vrtc->alarm_time, local_time);
0104         alarm_secs = vrtc->alarm_time - local_time;
0105         if (alarm_secs > 0) {
0106             meson_vrtc_set_wakeup_time(vrtc, alarm_secs);
0107             dev_dbg(dev, "system will wakeup in %lds.\n",
0108                 alarm_secs);
0109         } else {
0110             dev_err(dev, "alarm time already passed: %lds.\n",
0111                 alarm_secs);
0112         }
0113     }
0114
0115     return 0;
0116 }
0117
0118 static int __maybe_unused meson_vrtc_resume(struct device *dev)
0119 {
0120     struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
0121
0122     dev_dbg(dev, "%s\n", __func__);
0123
0124     vrtc->alarm_time = 0;
0125     meson_vrtc_set_wakeup_time(vrtc, 0);
0126     return 0;
0127 }
0128
0129 static SIMPLE_DEV_PM_OPS(meson_vrtc_pm_ops,
0130              meson_vrtc_suspend, meson_vrtc_resume);
0131
0132 static const struct of_device_id meson_vrtc_dt_match[] = {
0133     { .compatible = "amlogic,meson-vrtc"},
0134     {},
0135 };
0136 MODULE_DEVICE_TABLE(of, meson_vrtc_dt_match);
0137
0138 static struct platform_driver meson_vrtc_driver = {
0139     .probe = meson_vrtc_probe,
0140     .driver = {
0141         .name = "meson-vrtc",
0142         .of_match_table = meson_vrtc_dt_match,
0143         .pm = &meson_vrtc_pm_ops,
0144     },
0145 };
0146
0147 module_platform_driver(meson_vrtc_driver);
0148
0149 MODULE_DESCRIPTION("Amlogic Virtual Wakeup RTC Timer driver");
0150 MODULE_LICENSE("GPL");