97 lines
1.8 KiB
C
97 lines
1.8 KiB
C
// SPDX-License-Identifier: GPL-2.0+
|
|
/*
|
|
* Copyright 2020, Heinrich Schuchardt <xypron.glpk@gmx.de>
|
|
*
|
|
* This driver emulates a real time clock based on timer ticks.
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <div64.h>
|
|
#include <dm.h>
|
|
#include <env.h>
|
|
#include <generated/timestamp_autogenerated.h>
|
|
#include <rtc.h>
|
|
|
|
/**
|
|
* struct emul_rtc - private data for emulated RTC driver
|
|
*/
|
|
struct emul_rtc {
|
|
/**
|
|
* @offset_us: microseconds from 1970-01-01 to timer_get_us() base
|
|
*/
|
|
u64 offset_us;
|
|
/**
|
|
* @isdst: daylight saving time
|
|
*/
|
|
int isdst;
|
|
};
|
|
|
|
static int emul_rtc_get(struct udevice *dev, struct rtc_time *time)
|
|
{
|
|
struct emul_rtc *priv = dev_get_priv(dev);
|
|
u64 now;
|
|
|
|
now = timer_get_us() + priv->offset_us;
|
|
do_div(now, 1000000);
|
|
rtc_to_tm(now, time);
|
|
time->tm_isdst = priv->isdst;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int emul_rtc_set(struct udevice *dev, const struct rtc_time *time)
|
|
{
|
|
struct emul_rtc *priv = dev_get_priv(dev);
|
|
|
|
if (time->tm_year < 1970)
|
|
return -EINVAL;
|
|
|
|
priv->offset_us = rtc_mktime(time) * 1000000ULL - timer_get_us();
|
|
|
|
if (time->tm_isdst > 0)
|
|
priv->isdst = 1;
|
|
else if (time->tm_isdst < 0)
|
|
priv->isdst = -1;
|
|
else
|
|
priv->isdst = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int emul_rtc_probe(struct udevice *dev)
|
|
{
|
|
struct emul_rtc *priv = dev_get_priv(dev);
|
|
const char *epoch_str;
|
|
u64 epoch;
|
|
|
|
epoch_str = env_get("rtc_emul_epoch");
|
|
|
|
if (epoch_str) {
|
|
epoch = simple_strtoull(epoch_str, NULL, 10);
|
|
} else {
|
|
/* Use the build date as initial time */
|
|
epoch = U_BOOT_EPOCH;
|
|
}
|
|
priv->offset_us = epoch * 1000000ULL - timer_get_us();
|
|
priv->isdst = -1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct rtc_ops emul_rtc_ops = {
|
|
.get = emul_rtc_get,
|
|
.set = emul_rtc_set,
|
|
};
|
|
|
|
U_BOOT_DRIVER(rtc_emul) = {
|
|
.name = "rtc_emul",
|
|
.id = UCLASS_RTC,
|
|
.ops = &emul_rtc_ops,
|
|
.probe = emul_rtc_probe,
|
|
.priv_auto = sizeof(struct emul_rtc),
|
|
};
|
|
|
|
U_BOOT_DRVINFO(rtc_emul) = {
|
|
.name = "rtc_emul",
|
|
};
|