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	int ret;
 69
 70	vrtc = devm_kzalloc(&pdev->dev, sizeof(*vrtc), GFP_KERNEL);
 71	if (!vrtc)
 72		return -ENOMEM;
 73
 74	vrtc->io_alarm = devm_platform_ioremap_resource(pdev, 0);
 75	if (IS_ERR(vrtc->io_alarm))
 76		return PTR_ERR(vrtc->io_alarm);
 77
 78	device_init_wakeup(&pdev->dev, 1);
 79
 80	platform_set_drvdata(pdev, vrtc);
 81
 82	vrtc->rtc = devm_rtc_allocate_device(&pdev->dev);
 83	if (IS_ERR(vrtc->rtc))
 84		return PTR_ERR(vrtc->rtc);
 85
 86	vrtc->rtc->ops = &meson_vrtc_ops;
 87	ret = rtc_register_device(vrtc->rtc);
 88	if (ret)
 89		return ret;
 90
 91	return 0;
 92}
 93
 94static int __maybe_unused meson_vrtc_suspend(struct device *dev)
 95{
 96	struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
 97
 98	dev_dbg(dev, "%s\n", __func__);
 99	if (vrtc->alarm_time) {
100		unsigned long local_time;
101		long alarm_secs;
102		struct timespec64 time;
103
104		ktime_get_raw_ts64(&time);
105		local_time = time.tv_sec;
106
107		dev_dbg(dev, "alarm_time = %lus, local_time=%lus\n",
108			vrtc->alarm_time, local_time);
109		alarm_secs = vrtc->alarm_time - local_time;
110		if (alarm_secs > 0) {
111			meson_vrtc_set_wakeup_time(vrtc, alarm_secs);
112			dev_dbg(dev, "system will wakeup in %lds.\n",
113				alarm_secs);
114		} else {
115			dev_err(dev, "alarm time already passed: %lds.\n",
116				alarm_secs);
117		}
118	}
119
120	return 0;
121}
122
123static int __maybe_unused meson_vrtc_resume(struct device *dev)
124{
125	struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
126
127	dev_dbg(dev, "%s\n", __func__);
128
129	vrtc->alarm_time = 0;
130	meson_vrtc_set_wakeup_time(vrtc, 0);
131	return 0;
132}
133
134static SIMPLE_DEV_PM_OPS(meson_vrtc_pm_ops,
135			 meson_vrtc_suspend, meson_vrtc_resume);
136
137static const struct of_device_id meson_vrtc_dt_match[] = {
138	{ .compatible = "amlogic,meson-vrtc"},
139	{},
140};
141MODULE_DEVICE_TABLE(of, meson_vrtc_dt_match);
142
143static struct platform_driver meson_vrtc_driver = {
144	.probe = meson_vrtc_probe,
145	.driver = {
146		.name = "meson-vrtc",
147		.of_match_table = meson_vrtc_dt_match,
148		.pm = &meson_vrtc_pm_ops,
149	},
150};
151
152module_platform_driver(meson_vrtc_driver);
153
154MODULE_DESCRIPTION("Amlogic Virtual Wakeup RTC Timer driver");
155MODULE_LICENSE("GPL");