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1/*
2 * rtc-efi: RTC Class Driver for EFI-based systems
3 *
4 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
5 *
6 * Author: dann frazier <dannf@hp.com>
7 * Based on efirtc.c by Stephane Eranian
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation; either version 2 of the License, or (at your
12 * option) any later version.
13 *
14 */
15
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/time.h>
19#include <linux/platform_device.h>
20#include <linux/rtc.h>
21#include <linux/efi.h>
22
23#define EFI_ISDST (EFI_TIME_ADJUST_DAYLIGHT|EFI_TIME_IN_DAYLIGHT)
24/*
25 * EFI Epoch is 1/1/1998
26 */
27#define EFI_RTC_EPOCH 1998
28
29/*
30 * returns day of the year [0-365]
31 */
32static inline int
33compute_yday(efi_time_t *eft)
34{
35 /* efi_time_t.month is in the [1-12] so, we need -1 */
36 return rtc_year_days(eft->day - 1, eft->month - 1, eft->year);
37}
38/*
39 * returns day of the week [0-6] 0=Sunday
40 *
41 * Don't try to provide a year that's before 1998, please !
42 */
43static int
44compute_wday(efi_time_t *eft)
45{
46 int y;
47 int ndays = 0;
48
49 if (eft->year < 1998) {
50 printk(KERN_ERR "efirtc: EFI year < 1998, invalid date\n");
51 return -1;
52 }
53
54 for (y = EFI_RTC_EPOCH; y < eft->year; y++)
55 ndays += 365 + (is_leap_year(y) ? 1 : 0);
56
57 ndays += compute_yday(eft);
58
59 /*
60 * 4=1/1/1998 was a Thursday
61 */
62 return (ndays + 4) % 7;
63}
64
65static void
66convert_to_efi_time(struct rtc_time *wtime, efi_time_t *eft)
67{
68 eft->year = wtime->tm_year + 1900;
69 eft->month = wtime->tm_mon + 1;
70 eft->day = wtime->tm_mday;
71 eft->hour = wtime->tm_hour;
72 eft->minute = wtime->tm_min;
73 eft->second = wtime->tm_sec;
74 eft->nanosecond = 0;
75 eft->daylight = wtime->tm_isdst ? EFI_ISDST : 0;
76 eft->timezone = EFI_UNSPECIFIED_TIMEZONE;
77}
78
79static void
80convert_from_efi_time(efi_time_t *eft, struct rtc_time *wtime)
81{
82 memset(wtime, 0, sizeof(*wtime));
83 wtime->tm_sec = eft->second;
84 wtime->tm_min = eft->minute;
85 wtime->tm_hour = eft->hour;
86 wtime->tm_mday = eft->day;
87 wtime->tm_mon = eft->month - 1;
88 wtime->tm_year = eft->year - 1900;
89
90 /* day of the week [0-6], Sunday=0 */
91 wtime->tm_wday = compute_wday(eft);
92
93 /* day in the year [1-365]*/
94 wtime->tm_yday = compute_yday(eft);
95
96
97 switch (eft->daylight & EFI_ISDST) {
98 case EFI_ISDST:
99 wtime->tm_isdst = 1;
100 break;
101 case EFI_TIME_ADJUST_DAYLIGHT:
102 wtime->tm_isdst = 0;
103 break;
104 default:
105 wtime->tm_isdst = -1;
106 }
107}
108
109static int efi_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
110{
111 efi_time_t eft;
112 efi_status_t status;
113
114 /*
115 * As of EFI v1.10, this call always returns an unsupported status
116 */
117 status = efi.get_wakeup_time((efi_bool_t *)&wkalrm->enabled,
118 (efi_bool_t *)&wkalrm->pending, &eft);
119
120 if (status != EFI_SUCCESS)
121 return -EINVAL;
122
123 convert_from_efi_time(&eft, &wkalrm->time);
124
125 return rtc_valid_tm(&wkalrm->time);
126}
127
128static int efi_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
129{
130 efi_time_t eft;
131 efi_status_t status;
132
133 convert_to_efi_time(&wkalrm->time, &eft);
134
135 /*
136 * XXX Fixme:
137 * As of EFI 0.92 with the firmware I have on my
138 * machine this call does not seem to work quite
139 * right
140 *
141 * As of v1.10, this call always returns an unsupported status
142 */
143 status = efi.set_wakeup_time((efi_bool_t)wkalrm->enabled, &eft);
144
145 printk(KERN_WARNING "write status is %d\n", (int)status);
146
147 return status == EFI_SUCCESS ? 0 : -EINVAL;
148}
149
150static int efi_read_time(struct device *dev, struct rtc_time *tm)
151{
152 efi_status_t status;
153 efi_time_t eft;
154 efi_time_cap_t cap;
155
156 status = efi.get_time(&eft, &cap);
157
158 if (status != EFI_SUCCESS) {
159 /* should never happen */
160 printk(KERN_ERR "efitime: can't read time\n");
161 return -EINVAL;
162 }
163
164 convert_from_efi_time(&eft, tm);
165
166 return rtc_valid_tm(tm);
167}
168
169static int efi_set_time(struct device *dev, struct rtc_time *tm)
170{
171 efi_status_t status;
172 efi_time_t eft;
173
174 convert_to_efi_time(tm, &eft);
175
176 status = efi.set_time(&eft);
177
178 return status == EFI_SUCCESS ? 0 : -EINVAL;
179}
180
181static const struct rtc_class_ops efi_rtc_ops = {
182 .read_time = efi_read_time,
183 .set_time = efi_set_time,
184 .read_alarm = efi_read_alarm,
185 .set_alarm = efi_set_alarm,
186};
187
188static int __init efi_rtc_probe(struct platform_device *dev)
189{
190 struct rtc_device *rtc;
191
192 rtc = rtc_device_register("rtc-efi", &dev->dev, &efi_rtc_ops,
193 THIS_MODULE);
194 if (IS_ERR(rtc))
195 return PTR_ERR(rtc);
196
197 platform_set_drvdata(dev, rtc);
198
199 return 0;
200}
201
202static int __exit efi_rtc_remove(struct platform_device *dev)
203{
204 struct rtc_device *rtc = platform_get_drvdata(dev);
205
206 rtc_device_unregister(rtc);
207
208 return 0;
209}
210
211static struct platform_driver efi_rtc_driver = {
212 .driver = {
213 .name = "rtc-efi",
214 .owner = THIS_MODULE,
215 },
216 .remove = __exit_p(efi_rtc_remove),
217};
218
219static int __init efi_rtc_init(void)
220{
221 return platform_driver_probe(&efi_rtc_driver, efi_rtc_probe);
222}
223
224static void __exit efi_rtc_exit(void)
225{
226 platform_driver_unregister(&efi_rtc_driver);
227}
228
229module_init(efi_rtc_init);
230module_exit(efi_rtc_exit);
231
232MODULE_AUTHOR("dann frazier <dannf@hp.com>");
233MODULE_LICENSE("GPL");
234MODULE_DESCRIPTION("EFI RTC driver");
1/*
2 * rtc-efi: RTC Class Driver for EFI-based systems
3 *
4 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
5 *
6 * Author: dann frazier <dannf@dannf.org>
7 * Based on efirtc.c by Stephane Eranian
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation; either version 2 of the License, or (at your
12 * option) any later version.
13 *
14 */
15
16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/stringify.h>
21#include <linux/time.h>
22#include <linux/platform_device.h>
23#include <linux/rtc.h>
24#include <linux/efi.h>
25
26#define EFI_ISDST (EFI_TIME_ADJUST_DAYLIGHT|EFI_TIME_IN_DAYLIGHT)
27
28/*
29 * returns day of the year [0-365]
30 */
31static inline int
32compute_yday(efi_time_t *eft)
33{
34 /* efi_time_t.month is in the [1-12] so, we need -1 */
35 return rtc_year_days(eft->day, eft->month - 1, eft->year);
36}
37
38/*
39 * returns day of the week [0-6] 0=Sunday
40 */
41static int
42compute_wday(efi_time_t *eft, int yday)
43{
44 int ndays = eft->year * (365 % 7)
45 + (eft->year - 1) / 4
46 - (eft->year - 1) / 100
47 + (eft->year - 1) / 400
48 + yday;
49
50 /*
51 * 1/1/0000 may or may not have been a Sunday (if it ever existed at
52 * all) but assuming it was makes this calculation work correctly.
53 */
54 return ndays % 7;
55}
56
57static void
58convert_to_efi_time(struct rtc_time *wtime, efi_time_t *eft)
59{
60 eft->year = wtime->tm_year + 1900;
61 eft->month = wtime->tm_mon + 1;
62 eft->day = wtime->tm_mday;
63 eft->hour = wtime->tm_hour;
64 eft->minute = wtime->tm_min;
65 eft->second = wtime->tm_sec;
66 eft->nanosecond = 0;
67 eft->daylight = wtime->tm_isdst ? EFI_ISDST : 0;
68 eft->timezone = EFI_UNSPECIFIED_TIMEZONE;
69}
70
71static bool
72convert_from_efi_time(efi_time_t *eft, struct rtc_time *wtime)
73{
74 memset(wtime, 0, sizeof(*wtime));
75
76 if (eft->second >= 60)
77 return false;
78 wtime->tm_sec = eft->second;
79
80 if (eft->minute >= 60)
81 return false;
82 wtime->tm_min = eft->minute;
83
84 if (eft->hour >= 24)
85 return false;
86 wtime->tm_hour = eft->hour;
87
88 if (!eft->day || eft->day > 31)
89 return false;
90 wtime->tm_mday = eft->day;
91
92 if (!eft->month || eft->month > 12)
93 return false;
94 wtime->tm_mon = eft->month - 1;
95
96 if (eft->year < 1900 || eft->year > 9999)
97 return false;
98 wtime->tm_year = eft->year - 1900;
99
100 /* day in the year [1-365]*/
101 wtime->tm_yday = compute_yday(eft);
102
103 /* day of the week [0-6], Sunday=0 */
104 wtime->tm_wday = compute_wday(eft, wtime->tm_yday);
105
106 switch (eft->daylight & EFI_ISDST) {
107 case EFI_ISDST:
108 wtime->tm_isdst = 1;
109 break;
110 case EFI_TIME_ADJUST_DAYLIGHT:
111 wtime->tm_isdst = 0;
112 break;
113 default:
114 wtime->tm_isdst = -1;
115 }
116
117 return true;
118}
119
120static int efi_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
121{
122 efi_time_t eft;
123 efi_status_t status;
124
125 /*
126 * As of EFI v1.10, this call always returns an unsupported status
127 */
128 status = efi.get_wakeup_time((efi_bool_t *)&wkalrm->enabled,
129 (efi_bool_t *)&wkalrm->pending, &eft);
130
131 if (status != EFI_SUCCESS)
132 return -EINVAL;
133
134 if (!convert_from_efi_time(&eft, &wkalrm->time))
135 return -EIO;
136
137 return rtc_valid_tm(&wkalrm->time);
138}
139
140static int efi_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
141{
142 efi_time_t eft;
143 efi_status_t status;
144
145 convert_to_efi_time(&wkalrm->time, &eft);
146
147 /*
148 * XXX Fixme:
149 * As of EFI 0.92 with the firmware I have on my
150 * machine this call does not seem to work quite
151 * right
152 *
153 * As of v1.10, this call always returns an unsupported status
154 */
155 status = efi.set_wakeup_time((efi_bool_t)wkalrm->enabled, &eft);
156
157 dev_warn(dev, "write status is %d\n", (int)status);
158
159 return status == EFI_SUCCESS ? 0 : -EINVAL;
160}
161
162static int efi_read_time(struct device *dev, struct rtc_time *tm)
163{
164 efi_status_t status;
165 efi_time_t eft;
166 efi_time_cap_t cap;
167
168 status = efi.get_time(&eft, &cap);
169
170 if (status != EFI_SUCCESS) {
171 /* should never happen */
172 dev_err(dev, "can't read time\n");
173 return -EINVAL;
174 }
175
176 if (!convert_from_efi_time(&eft, tm))
177 return -EIO;
178
179 return rtc_valid_tm(tm);
180}
181
182static int efi_set_time(struct device *dev, struct rtc_time *tm)
183{
184 efi_status_t status;
185 efi_time_t eft;
186
187 convert_to_efi_time(tm, &eft);
188
189 status = efi.set_time(&eft);
190
191 return status == EFI_SUCCESS ? 0 : -EINVAL;
192}
193
194static int efi_procfs(struct device *dev, struct seq_file *seq)
195{
196 efi_time_t eft, alm;
197 efi_time_cap_t cap;
198 efi_bool_t enabled, pending;
199
200 memset(&eft, 0, sizeof(eft));
201 memset(&alm, 0, sizeof(alm));
202 memset(&cap, 0, sizeof(cap));
203
204 efi.get_time(&eft, &cap);
205 efi.get_wakeup_time(&enabled, &pending, &alm);
206
207 seq_printf(seq,
208 "Time\t\t: %u:%u:%u.%09u\n"
209 "Date\t\t: %u-%u-%u\n"
210 "Daylight\t: %u\n",
211 eft.hour, eft.minute, eft.second, eft.nanosecond,
212 eft.year, eft.month, eft.day,
213 eft.daylight);
214
215 if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE)
216 seq_puts(seq, "Timezone\t: unspecified\n");
217 else
218 /* XXX fixme: convert to string? */
219 seq_printf(seq, "Timezone\t: %u\n", eft.timezone);
220
221 seq_printf(seq,
222 "Alarm Time\t: %u:%u:%u.%09u\n"
223 "Alarm Date\t: %u-%u-%u\n"
224 "Alarm Daylight\t: %u\n"
225 "Enabled\t\t: %s\n"
226 "Pending\t\t: %s\n",
227 alm.hour, alm.minute, alm.second, alm.nanosecond,
228 alm.year, alm.month, alm.day,
229 alm.daylight,
230 enabled == 1 ? "yes" : "no",
231 pending == 1 ? "yes" : "no");
232
233 if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE)
234 seq_puts(seq, "Timezone\t: unspecified\n");
235 else
236 /* XXX fixme: convert to string? */
237 seq_printf(seq, "Timezone\t: %u\n", alm.timezone);
238
239 /*
240 * now prints the capabilities
241 */
242 seq_printf(seq,
243 "Resolution\t: %u\n"
244 "Accuracy\t: %u\n"
245 "SetstoZero\t: %u\n",
246 cap.resolution, cap.accuracy, cap.sets_to_zero);
247
248 return 0;
249}
250
251static const struct rtc_class_ops efi_rtc_ops = {
252 .read_time = efi_read_time,
253 .set_time = efi_set_time,
254 .read_alarm = efi_read_alarm,
255 .set_alarm = efi_set_alarm,
256 .proc = efi_procfs,
257};
258
259static int __init efi_rtc_probe(struct platform_device *dev)
260{
261 struct rtc_device *rtc;
262
263 rtc = devm_rtc_device_register(&dev->dev, "rtc-efi", &efi_rtc_ops,
264 THIS_MODULE);
265 if (IS_ERR(rtc))
266 return PTR_ERR(rtc);
267
268 rtc->uie_unsupported = 1;
269 platform_set_drvdata(dev, rtc);
270
271 return 0;
272}
273
274static struct platform_driver efi_rtc_driver = {
275 .driver = {
276 .name = "rtc-efi",
277 },
278};
279
280module_platform_driver_probe(efi_rtc_driver, efi_rtc_probe);
281
282MODULE_ALIAS("platform:rtc-efi");
283MODULE_AUTHOR("dann frazier <dannf@dannf.org>");
284MODULE_LICENSE("GPL");
285MODULE_DESCRIPTION("EFI RTC driver");
286MODULE_ALIAS("platform:rtc-efi");