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
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
|
/*
* rtc-efi: RTC Class Driver for EFI-based systems
*
* Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
*
* Author: dann frazier <dannf@hp.com>
* Based on efirtc.c by Stephane Eranian
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/stringify.h>
#include <linux/time.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/efi.h>
#define EFI_ISDST (EFI_TIME_ADJUST_DAYLIGHT|EFI_TIME_IN_DAYLIGHT)
/*
* EFI Epoch is 1/1/1998
*/
#define EFI_RTC_EPOCH 1998
/*
* returns day of the year [0-365]
*/
static inline int
compute_yday(efi_time_t *eft)
{
/* efi_time_t.month is in the [1-12] so, we need -1 */
return rtc_year_days(eft->day, eft->month - 1, eft->year);
}
/*
* returns day of the week [0-6] 0=Sunday
*
* Don't try to provide a year that's before 1998, please !
*/
static int
compute_wday(efi_time_t *eft)
{
int y;
int ndays = 0;
if (eft->year < EFI_RTC_EPOCH) {
pr_err("EFI year < " __stringify(EFI_RTC_EPOCH) ", invalid date\n");
return -1;
}
for (y = EFI_RTC_EPOCH; y < eft->year; y++)
ndays += 365 + (is_leap_year(y) ? 1 : 0);
ndays += compute_yday(eft);
/*
* 4=1/1/1998 was a Thursday
*/
return (ndays + 4) % 7;
}
static void
convert_to_efi_time(struct rtc_time *wtime, efi_time_t *eft)
{
eft->year = wtime->tm_year + 1900;
eft->month = wtime->tm_mon + 1;
eft->day = wtime->tm_mday;
eft->hour = wtime->tm_hour;
eft->minute = wtime->tm_min;
eft->second = wtime->tm_sec;
eft->nanosecond = 0;
eft->daylight = wtime->tm_isdst ? EFI_ISDST : 0;
eft->timezone = EFI_UNSPECIFIED_TIMEZONE;
}
static bool
convert_from_efi_time(efi_time_t *eft, struct rtc_time *wtime)
{
memset(wtime, 0, sizeof(*wtime));
if (eft->second >= 60)
return false;
wtime->tm_sec = eft->second;
if (eft->minute >= 60)
return false;
wtime->tm_min = eft->minute;
if (eft->hour >= 24)
return false;
wtime->tm_hour = eft->hour;
if (!eft->day || eft->day > 31)
return false;
wtime->tm_mday = eft->day;
if (!eft->month || eft->month > 12)
return false;
wtime->tm_mon = eft->month - 1;
wtime->tm_year = eft->year - 1900;
/* day of the week [0-6], Sunday=0 */
wtime->tm_wday = compute_wday(eft);
if (wtime->tm_wday < 0)
return false;
/* day in the year [1-365]*/
wtime->tm_yday = compute_yday(eft);
switch (eft->daylight & EFI_ISDST) {
case EFI_ISDST:
wtime->tm_isdst = 1;
break;
case EFI_TIME_ADJUST_DAYLIGHT:
wtime->tm_isdst = 0;
break;
default:
wtime->tm_isdst = -1;
}
return true;
}
static int efi_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
efi_time_t eft;
efi_status_t status;
/*
* As of EFI v1.10, this call always returns an unsupported status
*/
status = efi.get_wakeup_time((efi_bool_t *)&wkalrm->enabled,
(efi_bool_t *)&wkalrm->pending, &eft);
if (status != EFI_SUCCESS)
return -EINVAL;
if (!convert_from_efi_time(&eft, &wkalrm->time))
return -EIO;
return rtc_valid_tm(&wkalrm->time);
}
static int efi_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
efi_time_t eft;
efi_status_t status;
convert_to_efi_time(&wkalrm->time, &eft);
/*
* XXX Fixme:
* As of EFI 0.92 with the firmware I have on my
* machine this call does not seem to work quite
* right
*
* As of v1.10, this call always returns an unsupported status
*/
status = efi.set_wakeup_time((efi_bool_t)wkalrm->enabled, &eft);
dev_warn(dev, "write status is %d\n", (int)status);
return status == EFI_SUCCESS ? 0 : -EINVAL;
}
static int efi_read_time(struct device *dev, struct rtc_time *tm)
{
efi_status_t status;
efi_time_t eft;
efi_time_cap_t cap;
status = efi.get_time(&eft, &cap);
if (status != EFI_SUCCESS) {
/* should never happen */
dev_err(dev, "can't read time\n");
return -EINVAL;
}
if (!convert_from_efi_time(&eft, tm))
return -EIO;
return rtc_valid_tm(tm);
}
static int efi_set_time(struct device *dev, struct rtc_time *tm)
{
efi_status_t status;
efi_time_t eft;
convert_to_efi_time(tm, &eft);
status = efi.set_time(&eft);
return status == EFI_SUCCESS ? 0 : -EINVAL;
}
static const struct rtc_class_ops efi_rtc_ops = {
.read_time = efi_read_time,
.set_time = efi_set_time,
.read_alarm = efi_read_alarm,
.set_alarm = efi_set_alarm,
};
static int __init efi_rtc_probe(struct platform_device *dev)
{
struct rtc_device *rtc;
rtc = devm_rtc_device_register(&dev->dev, "rtc-efi", &efi_rtc_ops,
THIS_MODULE);
if (IS_ERR(rtc))
return PTR_ERR(rtc);
platform_set_drvdata(dev, rtc);
return 0;
}
static struct platform_driver efi_rtc_driver = {
.driver = {
.name = "rtc-efi",
.owner = THIS_MODULE,
},
};
module_platform_driver_probe(efi_rtc_driver, efi_rtc_probe);
MODULE_ALIAS("platform:rtc-efi");
MODULE_AUTHOR("dann frazier <dannf@hp.com>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("EFI RTC driver");
|
