linuxdebug/arch/um/drivers/rtc_kern.c

212 lines
4.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2020 Intel Corporation
* Author: Johannes Berg <johannes@sipsolutions.net>
*/
#include <linux/platform_device.h>
#include <linux/time-internal.h>
#include <linux/suspend.h>
#include <linux/err.h>
#include <linux/rtc.h>
#include <kern_util.h>
#include <irq_kern.h>
#include <os.h>
#include "rtc.h"
static time64_t uml_rtc_alarm_time;
static bool uml_rtc_alarm_enabled;
static struct rtc_device *uml_rtc;
static int uml_rtc_irq_fd, uml_rtc_irq;
#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
static void uml_rtc_time_travel_alarm(struct time_travel_event *ev)
{
uml_rtc_send_timetravel_alarm();
}
static struct time_travel_event uml_rtc_alarm_event = {
.fn = uml_rtc_time_travel_alarm,
};
#endif
static int uml_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct timespec64 ts;
/* Use this to get correct time in time-travel mode */
read_persistent_clock64(&ts);
rtc_time64_to_tm(timespec64_to_ktime(ts) / NSEC_PER_SEC, tm);
return 0;
}
static int uml_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
rtc_time64_to_tm(uml_rtc_alarm_time, &alrm->time);
alrm->enabled = uml_rtc_alarm_enabled;
return 0;
}
static int uml_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
{
unsigned long long secs;
if (!enable && !uml_rtc_alarm_enabled)
return 0;
uml_rtc_alarm_enabled = enable;
secs = uml_rtc_alarm_time - ktime_get_real_seconds();
if (time_travel_mode == TT_MODE_OFF) {
if (!enable) {
uml_rtc_disable_alarm();
return 0;
}
/* enable or update */
return uml_rtc_enable_alarm(secs);
} else {
time_travel_del_event(&uml_rtc_alarm_event);
if (enable)
time_travel_add_event_rel(&uml_rtc_alarm_event,
secs * NSEC_PER_SEC);
}
return 0;
}
static int uml_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
uml_rtc_alarm_irq_enable(dev, 0);
uml_rtc_alarm_time = rtc_tm_to_time64(&alrm->time);
uml_rtc_alarm_irq_enable(dev, alrm->enabled);
return 0;
}
static const struct rtc_class_ops uml_rtc_ops = {
.read_time = uml_rtc_read_time,
.read_alarm = uml_rtc_read_alarm,
.alarm_irq_enable = uml_rtc_alarm_irq_enable,
.set_alarm = uml_rtc_set_alarm,
};
static irqreturn_t uml_rtc_interrupt(int irq, void *data)
{
unsigned long long c = 0;
/* alarm triggered, it's now off */
uml_rtc_alarm_enabled = false;
os_read_file(uml_rtc_irq_fd, &c, sizeof(c));
WARN_ON(c == 0);
pm_system_wakeup();
rtc_update_irq(uml_rtc, 1, RTC_IRQF | RTC_AF);
return IRQ_HANDLED;
}
static int uml_rtc_setup(void)
{
int err;
err = uml_rtc_start(time_travel_mode != TT_MODE_OFF);
if (WARN(err < 0, "err = %d\n", err))
return err;
uml_rtc_irq_fd = err;
err = um_request_irq(UM_IRQ_ALLOC, uml_rtc_irq_fd, IRQ_READ,
uml_rtc_interrupt, 0, "rtc", NULL);
if (err < 0) {
uml_rtc_stop(time_travel_mode != TT_MODE_OFF);
return err;
}
irq_set_irq_wake(err, 1);
uml_rtc_irq = err;
return 0;
}
static void uml_rtc_cleanup(void)
{
um_free_irq(uml_rtc_irq, NULL);
uml_rtc_stop(time_travel_mode != TT_MODE_OFF);
}
static int uml_rtc_probe(struct platform_device *pdev)
{
int err;
err = uml_rtc_setup();
if (err)
return err;
uml_rtc = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(uml_rtc)) {
err = PTR_ERR(uml_rtc);
goto cleanup;
}
uml_rtc->ops = &uml_rtc_ops;
device_init_wakeup(&pdev->dev, 1);
err = devm_rtc_register_device(uml_rtc);
if (err)
goto cleanup;
return 0;
cleanup:
uml_rtc_cleanup();
return err;
}
static int uml_rtc_remove(struct platform_device *pdev)
{
device_init_wakeup(&pdev->dev, 0);
uml_rtc_cleanup();
return 0;
}
static struct platform_driver uml_rtc_driver = {
.probe = uml_rtc_probe,
.remove = uml_rtc_remove,
.driver = {
.name = "uml-rtc",
},
};
static int __init uml_rtc_init(void)
{
struct platform_device *pdev;
int err;
err = platform_driver_register(&uml_rtc_driver);
if (err)
return err;
pdev = platform_device_alloc("uml-rtc", 0);
if (!pdev) {
err = -ENOMEM;
goto unregister;
}
err = platform_device_add(pdev);
if (err)
goto unregister;
return 0;
unregister:
platform_device_put(pdev);
platform_driver_unregister(&uml_rtc_driver);
return err;
}
device_initcall(uml_rtc_init);