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");