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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 .probe = efi_rtc_probe,
217 .remove = __exit_p(efi_rtc_remove),
218};
219
220static int __init efi_rtc_init(void)
221{
222 return platform_driver_probe(&efi_rtc_driver, efi_rtc_probe);
223}
224
225static void __exit efi_rtc_exit(void)
226{
227 platform_driver_unregister(&efi_rtc_driver);
228}
229
230module_init(efi_rtc_init);
231module_exit(efi_rtc_exit);
232
233MODULE_AUTHOR("dann frazier <dannf@hp.com>");
234MODULE_LICENSE("GPL");
235MODULE_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@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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/time.h>
21#include <linux/platform_device.h>
22#include <linux/rtc.h>
23#include <linux/efi.h>
24
25#define EFI_ISDST (EFI_TIME_ADJUST_DAYLIGHT|EFI_TIME_IN_DAYLIGHT)
26/*
27 * EFI Epoch is 1/1/1998
28 */
29#define EFI_RTC_EPOCH 1998
30
31/*
32 * returns day of the year [0-365]
33 */
34static inline int
35compute_yday(efi_time_t *eft)
36{
37 /* efi_time_t.month is in the [1-12] so, we need -1 */
38 return rtc_year_days(eft->day - 1, eft->month - 1, eft->year);
39}
40/*
41 * returns day of the week [0-6] 0=Sunday
42 *
43 * Don't try to provide a year that's before 1998, please !
44 */
45static int
46compute_wday(efi_time_t *eft)
47{
48 int y;
49 int ndays = 0;
50
51 if (eft->year < 1998) {
52 pr_err("EFI year < 1998, invalid date\n");
53 return -1;
54 }
55
56 for (y = EFI_RTC_EPOCH; y < eft->year; y++)
57 ndays += 365 + (is_leap_year(y) ? 1 : 0);
58
59 ndays += compute_yday(eft);
60
61 /*
62 * 4=1/1/1998 was a Thursday
63 */
64 return (ndays + 4) % 7;
65}
66
67static void
68convert_to_efi_time(struct rtc_time *wtime, efi_time_t *eft)
69{
70 eft->year = wtime->tm_year + 1900;
71 eft->month = wtime->tm_mon + 1;
72 eft->day = wtime->tm_mday;
73 eft->hour = wtime->tm_hour;
74 eft->minute = wtime->tm_min;
75 eft->second = wtime->tm_sec;
76 eft->nanosecond = 0;
77 eft->daylight = wtime->tm_isdst ? EFI_ISDST : 0;
78 eft->timezone = EFI_UNSPECIFIED_TIMEZONE;
79}
80
81static void
82convert_from_efi_time(efi_time_t *eft, struct rtc_time *wtime)
83{
84 memset(wtime, 0, sizeof(*wtime));
85 wtime->tm_sec = eft->second;
86 wtime->tm_min = eft->minute;
87 wtime->tm_hour = eft->hour;
88 wtime->tm_mday = eft->day;
89 wtime->tm_mon = eft->month - 1;
90 wtime->tm_year = eft->year - 1900;
91
92 /* day of the week [0-6], Sunday=0 */
93 wtime->tm_wday = compute_wday(eft);
94
95 /* day in the year [1-365]*/
96 wtime->tm_yday = compute_yday(eft);
97
98
99 switch (eft->daylight & EFI_ISDST) {
100 case EFI_ISDST:
101 wtime->tm_isdst = 1;
102 break;
103 case EFI_TIME_ADJUST_DAYLIGHT:
104 wtime->tm_isdst = 0;
105 break;
106 default:
107 wtime->tm_isdst = -1;
108 }
109}
110
111static int efi_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
112{
113 efi_time_t eft;
114 efi_status_t status;
115
116 /*
117 * As of EFI v1.10, this call always returns an unsupported status
118 */
119 status = efi.get_wakeup_time((efi_bool_t *)&wkalrm->enabled,
120 (efi_bool_t *)&wkalrm->pending, &eft);
121
122 if (status != EFI_SUCCESS)
123 return -EINVAL;
124
125 convert_from_efi_time(&eft, &wkalrm->time);
126
127 return rtc_valid_tm(&wkalrm->time);
128}
129
130static int efi_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
131{
132 efi_time_t eft;
133 efi_status_t status;
134
135 convert_to_efi_time(&wkalrm->time, &eft);
136
137 /*
138 * XXX Fixme:
139 * As of EFI 0.92 with the firmware I have on my
140 * machine this call does not seem to work quite
141 * right
142 *
143 * As of v1.10, this call always returns an unsupported status
144 */
145 status = efi.set_wakeup_time((efi_bool_t)wkalrm->enabled, &eft);
146
147 dev_warn(dev, "write status is %d\n", (int)status);
148
149 return status == EFI_SUCCESS ? 0 : -EINVAL;
150}
151
152static int efi_read_time(struct device *dev, struct rtc_time *tm)
153{
154 efi_status_t status;
155 efi_time_t eft;
156 efi_time_cap_t cap;
157
158 status = efi.get_time(&eft, &cap);
159
160 if (status != EFI_SUCCESS) {
161 /* should never happen */
162 dev_err(dev, "can't read time\n");
163 return -EINVAL;
164 }
165
166 convert_from_efi_time(&eft, tm);
167
168 return rtc_valid_tm(tm);
169}
170
171static int efi_set_time(struct device *dev, struct rtc_time *tm)
172{
173 efi_status_t status;
174 efi_time_t eft;
175
176 convert_to_efi_time(tm, &eft);
177
178 status = efi.set_time(&eft);
179
180 return status == EFI_SUCCESS ? 0 : -EINVAL;
181}
182
183static const struct rtc_class_ops efi_rtc_ops = {
184 .read_time = efi_read_time,
185 .set_time = efi_set_time,
186 .read_alarm = efi_read_alarm,
187 .set_alarm = efi_set_alarm,
188};
189
190static int __init efi_rtc_probe(struct platform_device *dev)
191{
192 struct rtc_device *rtc;
193
194 rtc = devm_rtc_device_register(&dev->dev, "rtc-efi", &efi_rtc_ops,
195 THIS_MODULE);
196 if (IS_ERR(rtc))
197 return PTR_ERR(rtc);
198
199 platform_set_drvdata(dev, rtc);
200
201 return 0;
202}
203
204static struct platform_driver efi_rtc_driver = {
205 .driver = {
206 .name = "rtc-efi",
207 .owner = THIS_MODULE,
208 },
209};
210
211module_platform_driver_probe(efi_rtc_driver, efi_rtc_probe);
212
213MODULE_AUTHOR("dann frazier <dannf@hp.com>");
214MODULE_LICENSE("GPL");
215MODULE_DESCRIPTION("EFI RTC driver");