rtc-meson-vrtc.c
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2019 BayLibre, SAS
* Author: Neil Armstrong <narmstrong@baylibre.com>
* Copyright (C) 2015 Amlogic, Inc. All rights reserved.
*/
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/time64.h>
struct meson_vrtc_data {
void __iomem *io_alarm;
struct rtc_device *rtc;
unsigned long alarm_time;
bool enabled;
};
static int meson_vrtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct timespec64 time;
dev_dbg(dev, "%s\n", __func__);
ktime_get_raw_ts64(&time);
rtc_time64_to_tm(time.tv_sec, tm);
return 0;
}
static void meson_vrtc_set_wakeup_time(struct meson_vrtc_data *vrtc,
unsigned long time)
{
writel_relaxed(time, vrtc->io_alarm);
}
static int meson_vrtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
dev_dbg(dev, "%s: alarm->enabled=%d\n", __func__, alarm->enabled);
if (alarm->enabled)
vrtc->alarm_time = rtc_tm_to_time64(&alarm->time);
else
vrtc->alarm_time = 0;
return 0;
}
static int meson_vrtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
vrtc->enabled = enabled;
return 0;
}
static const struct rtc_class_ops meson_vrtc_ops = {
.read_time = meson_vrtc_read_time,
.set_alarm = meson_vrtc_set_alarm,
.alarm_irq_enable = meson_vrtc_alarm_irq_enable,
};
static int meson_vrtc_probe(struct platform_device *pdev)
{
struct meson_vrtc_data *vrtc;
int ret;
vrtc = devm_kzalloc(&pdev->dev, sizeof(*vrtc), GFP_KERNEL);
if (!vrtc)
return -ENOMEM;
vrtc->io_alarm = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(vrtc->io_alarm))
return PTR_ERR(vrtc->io_alarm);
device_init_wakeup(&pdev->dev, 1);
platform_set_drvdata(pdev, vrtc);
vrtc->rtc = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(vrtc->rtc))
return PTR_ERR(vrtc->rtc);
vrtc->rtc->ops = &meson_vrtc_ops;
ret = rtc_register_device(vrtc->rtc);
if (ret)
return ret;
return 0;
}
static int __maybe_unused meson_vrtc_suspend(struct device *dev)
{
struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
dev_dbg(dev, "%s\n", __func__);
if (vrtc->alarm_time) {
unsigned long local_time;
long alarm_secs;
struct timespec64 time;
ktime_get_raw_ts64(&time);
local_time = time.tv_sec;
dev_dbg(dev, "alarm_time = %lus, local_time=%lus\n",
vrtc->alarm_time, local_time);
alarm_secs = vrtc->alarm_time - local_time;
if (alarm_secs > 0) {
meson_vrtc_set_wakeup_time(vrtc, alarm_secs);
dev_dbg(dev, "system will wakeup in %lds.\n",
alarm_secs);
} else {
dev_err(dev, "alarm time already passed: %lds.\n",
alarm_secs);
}
}
return 0;
}
static int __maybe_unused meson_vrtc_resume(struct device *dev)
{
struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
dev_dbg(dev, "%s\n", __func__);
vrtc->alarm_time = 0;
meson_vrtc_set_wakeup_time(vrtc, 0);
return 0;
}
static SIMPLE_DEV_PM_OPS(meson_vrtc_pm_ops,
meson_vrtc_suspend, meson_vrtc_resume);
static const struct of_device_id meson_vrtc_dt_match[] = {
{ .compatible = "amlogic,meson-vrtc"},
{},
};
MODULE_DEVICE_TABLE(of, meson_vrtc_dt_match);
static struct platform_driver meson_vrtc_driver = {
.probe = meson_vrtc_probe,
.driver = {
.name = "meson-vrtc",
.of_match_table = meson_vrtc_dt_match,
.pm = &meson_vrtc_pm_ops,
},
};
module_platform_driver(meson_vrtc_driver);
MODULE_DESCRIPTION("Amlogic Virtual Wakeup RTC Timer driver");
MODULE_LICENSE("GPL");