1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
|
// 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_alloc_size = sizeof(struct emul_rtc),
};
U_BOOT_DEVICE(rtc_emul) = {
.name = "rtc_emul",
};
|
