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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * rtc-efi: RTC Class Driver for EFI-based systems
4 *
5 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
6 *
7 * Author: dann frazier <dannf@dannf.org>
8 * Based on efirtc.c by Stephane Eranian
9 */
10
11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/stringify.h>
16#include <linux/time.h>
17#include <linux/platform_device.h>
18#include <linux/rtc.h>
19#include <linux/efi.h>
20
21#define EFI_ISDST (EFI_TIME_ADJUST_DAYLIGHT|EFI_TIME_IN_DAYLIGHT)
22
23/*
24 * returns day of the year [0-365]
25 */
26static inline int
27compute_yday(efi_time_t *eft)
28{
29 /* efi_time_t.month is in the [1-12] so, we need -1 */
30 return rtc_year_days(eft->day, eft->month - 1, eft->year);
31}
32
33/*
34 * returns day of the week [0-6] 0=Sunday
35 */
36static int
37compute_wday(efi_time_t *eft, int yday)
38{
39 int ndays = eft->year * (365 % 7)
40 + (eft->year - 1) / 4
41 - (eft->year - 1) / 100
42 + (eft->year - 1) / 400
43 + yday;
44
45 /*
46 * 1/1/0000 may or may not have been a Sunday (if it ever existed at
47 * all) but assuming it was makes this calculation work correctly.
48 */
49 return ndays % 7;
50}
51
52static void
53convert_to_efi_time(struct rtc_time *wtime, efi_time_t *eft)
54{
55 eft->year = wtime->tm_year + 1900;
56 eft->month = wtime->tm_mon + 1;
57 eft->day = wtime->tm_mday;
58 eft->hour = wtime->tm_hour;
59 eft->minute = wtime->tm_min;
60 eft->second = wtime->tm_sec;
61 eft->nanosecond = 0;
62 eft->daylight = wtime->tm_isdst ? EFI_ISDST : 0;
63 eft->timezone = EFI_UNSPECIFIED_TIMEZONE;
64}
65
66static bool
67convert_from_efi_time(efi_time_t *eft, struct rtc_time *wtime)
68{
69 memset(wtime, 0, sizeof(*wtime));
70
71 if (eft->second >= 60)
72 return false;
73 wtime->tm_sec = eft->second;
74
75 if (eft->minute >= 60)
76 return false;
77 wtime->tm_min = eft->minute;
78
79 if (eft->hour >= 24)
80 return false;
81 wtime->tm_hour = eft->hour;
82
83 if (!eft->day || eft->day > 31)
84 return false;
85 wtime->tm_mday = eft->day;
86
87 if (!eft->month || eft->month > 12)
88 return false;
89 wtime->tm_mon = eft->month - 1;
90
91 if (eft->year < 1900 || eft->year > 9999)
92 return false;
93 wtime->tm_year = eft->year - 1900;
94
95 /* day in the year [1-365]*/
96 wtime->tm_yday = compute_yday(eft);
97
98 /* day of the week [0-6], Sunday=0 */
99 wtime->tm_wday = compute_wday(eft, wtime->tm_yday);
100
101 switch (eft->daylight & EFI_ISDST) {
102 case EFI_ISDST:
103 wtime->tm_isdst = 1;
104 break;
105 case EFI_TIME_ADJUST_DAYLIGHT:
106 wtime->tm_isdst = 0;
107 break;
108 default:
109 wtime->tm_isdst = -1;
110 }
111
112 return true;
113}
114
115static int efi_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
116{
117 efi_time_t eft;
118 efi_status_t status;
119
120 /*
121 * As of EFI v1.10, this call always returns an unsupported status
122 */
123 status = efi.get_wakeup_time((efi_bool_t *)&wkalrm->enabled,
124 (efi_bool_t *)&wkalrm->pending, &eft);
125
126 if (status != EFI_SUCCESS)
127 return -EINVAL;
128
129 if (!convert_from_efi_time(&eft, &wkalrm->time))
130 return -EIO;
131
132 return rtc_valid_tm(&wkalrm->time);
133}
134
135static int efi_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
136{
137 efi_time_t eft;
138 efi_status_t status;
139
140 convert_to_efi_time(&wkalrm->time, &eft);
141
142 /*
143 * XXX Fixme:
144 * As of EFI 0.92 with the firmware I have on my
145 * machine this call does not seem to work quite
146 * right
147 *
148 * As of v1.10, this call always returns an unsupported status
149 */
150 status = efi.set_wakeup_time((efi_bool_t)wkalrm->enabled, &eft);
151
152 dev_warn(dev, "write status is %d\n", (int)status);
153
154 return status == EFI_SUCCESS ? 0 : -EINVAL;
155}
156
157static int efi_read_time(struct device *dev, struct rtc_time *tm)
158{
159 efi_status_t status;
160 efi_time_t eft;
161 efi_time_cap_t cap;
162
163 status = efi.get_time(&eft, &cap);
164
165 if (status != EFI_SUCCESS) {
166 /* should never happen */
167 dev_err(dev, "can't read time\n");
168 return -EINVAL;
169 }
170
171 if (!convert_from_efi_time(&eft, tm))
172 return -EIO;
173
174 return 0;
175}
176
177static int efi_set_time(struct device *dev, struct rtc_time *tm)
178{
179 efi_status_t status;
180 efi_time_t eft;
181
182 convert_to_efi_time(tm, &eft);
183
184 status = efi.set_time(&eft);
185
186 return status == EFI_SUCCESS ? 0 : -EINVAL;
187}
188
189static int efi_procfs(struct device *dev, struct seq_file *seq)
190{
191 efi_time_t eft, alm;
192 efi_time_cap_t cap;
193 efi_bool_t enabled, pending;
194 struct rtc_device *rtc = dev_get_drvdata(dev);
195
196 memset(&eft, 0, sizeof(eft));
197 memset(&alm, 0, sizeof(alm));
198 memset(&cap, 0, sizeof(cap));
199
200 efi.get_time(&eft, &cap);
201 efi.get_wakeup_time(&enabled, &pending, &alm);
202
203 seq_printf(seq,
204 "Time\t\t: %u:%u:%u.%09u\n"
205 "Date\t\t: %u-%u-%u\n"
206 "Daylight\t: %u\n",
207 eft.hour, eft.minute, eft.second, eft.nanosecond,
208 eft.year, eft.month, eft.day,
209 eft.daylight);
210
211 if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE)
212 seq_puts(seq, "Timezone\t: unspecified\n");
213 else
214 /* XXX fixme: convert to string? */
215 seq_printf(seq, "Timezone\t: %u\n", eft.timezone);
216
217 if (test_bit(RTC_FEATURE_ALARM, rtc->features)) {
218 seq_printf(seq,
219 "Alarm Time\t: %u:%u:%u.%09u\n"
220 "Alarm Date\t: %u-%u-%u\n"
221 "Alarm Daylight\t: %u\n"
222 "Enabled\t\t: %s\n"
223 "Pending\t\t: %s\n",
224 alm.hour, alm.minute, alm.second, alm.nanosecond,
225 alm.year, alm.month, alm.day,
226 alm.daylight,
227 enabled == 1 ? "yes" : "no",
228 pending == 1 ? "yes" : "no");
229
230 if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE)
231 seq_puts(seq, "Timezone\t: unspecified\n");
232 else
233 /* XXX fixme: convert to string? */
234 seq_printf(seq, "Timezone\t: %u\n", alm.timezone);
235 }
236
237 /*
238 * now prints the capabilities
239 */
240 seq_printf(seq,
241 "Resolution\t: %u\n"
242 "Accuracy\t: %u\n"
243 "SetstoZero\t: %u\n",
244 cap.resolution, cap.accuracy, cap.sets_to_zero);
245
246 return 0;
247}
248
249static const struct rtc_class_ops efi_rtc_ops = {
250 .read_time = efi_read_time,
251 .set_time = efi_set_time,
252 .read_alarm = efi_read_alarm,
253 .set_alarm = efi_set_alarm,
254 .proc = efi_procfs,
255};
256
257static int __init efi_rtc_probe(struct platform_device *dev)
258{
259 struct rtc_device *rtc;
260 efi_time_t eft;
261 efi_time_cap_t cap;
262
263 /* First check if the RTC is usable */
264 if (efi.get_time(&eft, &cap) != EFI_SUCCESS)
265 return -ENODEV;
266
267 rtc = devm_rtc_allocate_device(&dev->dev);
268 if (IS_ERR(rtc))
269 return PTR_ERR(rtc);
270
271 platform_set_drvdata(dev, rtc);
272
273 rtc->ops = &efi_rtc_ops;
274 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
275 if (efi_rt_services_supported(EFI_RT_SUPPORTED_WAKEUP_SERVICES))
276 set_bit(RTC_FEATURE_ALARM_WAKEUP_ONLY, rtc->features);
277 else
278 clear_bit(RTC_FEATURE_ALARM, rtc->features);
279
280 device_init_wakeup(&dev->dev, true);
281
282 return devm_rtc_register_device(rtc);
283}
284
285static struct platform_driver efi_rtc_driver = {
286 .driver = {
287 .name = "rtc-efi",
288 },
289};
290
291module_platform_driver_probe(efi_rtc_driver, efi_rtc_probe);
292
293MODULE_AUTHOR("dann frazier <dannf@dannf.org>");
294MODULE_LICENSE("GPL");
295MODULE_DESCRIPTION("EFI RTC driver");
296MODULE_ALIAS("platform:rtc-efi");
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");