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5e3fd9e5 | 1 | /* |
2 | * rtc-efi: RTC Class Driver for EFI-based systems | |
3 | * | |
4 | * Copyright (C) 2009 Hewlett-Packard Development Company, L.P. | |
5 | * | |
37563e5e | 6 | * Author: dann frazier <dannf@dannf.org> |
5e3fd9e5 | 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 | ||
34650f9e JH |
16 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
17 | ||
5e3fd9e5 | 18 | #include <linux/kernel.h> |
19 | #include <linux/module.h> | |
6e85bab6 | 20 | #include <linux/stringify.h> |
5e3fd9e5 | 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) | |
5e3fd9e5 | 27 | |
28 | /* | |
29 | * returns day of the year [0-365] | |
30 | */ | |
31 | static inline int | |
32 | compute_yday(efi_time_t *eft) | |
33 | { | |
34 | /* efi_time_t.month is in the [1-12] so, we need -1 */ | |
809d9627 | 35 | return rtc_year_days(eft->day, eft->month - 1, eft->year); |
5e3fd9e5 | 36 | } |
b2bd2370 | 37 | |
5e3fd9e5 | 38 | /* |
39 | * returns day of the week [0-6] 0=Sunday | |
5e3fd9e5 | 40 | */ |
41 | static int | |
b2bd2370 | 42 | compute_wday(efi_time_t *eft, int yday) |
5e3fd9e5 | 43 | { |
b2bd2370 AB |
44 | int ndays = eft->year * (365 % 7) |
45 | + (eft->year - 1) / 4 | |
46 | - (eft->year - 1) / 100 | |
47 | + (eft->year - 1) / 400 | |
48 | + yday; | |
5e3fd9e5 | 49 | |
50 | /* | |
b2bd2370 AB |
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. | |
5e3fd9e5 | 53 | */ |
b2bd2370 | 54 | return ndays % 7; |
5e3fd9e5 | 55 | } |
56 | ||
57 | static void | |
58 | convert_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; | |
34650f9e | 65 | eft->second = wtime->tm_sec; |
5e3fd9e5 | 66 | eft->nanosecond = 0; |
67 | eft->daylight = wtime->tm_isdst ? EFI_ISDST : 0; | |
68 | eft->timezone = EFI_UNSPECIFIED_TIMEZONE; | |
69 | } | |
70 | ||
6e85bab6 | 71 | static bool |
5e3fd9e5 | 72 | convert_from_efi_time(efi_time_t *eft, struct rtc_time *wtime) |
73 | { | |
74 | memset(wtime, 0, sizeof(*wtime)); | |
6e85bab6 JB |
75 | |
76 | if (eft->second >= 60) | |
77 | return false; | |
5e3fd9e5 | 78 | wtime->tm_sec = eft->second; |
6e85bab6 JB |
79 | |
80 | if (eft->minute >= 60) | |
81 | return false; | |
5e3fd9e5 | 82 | wtime->tm_min = eft->minute; |
6e85bab6 JB |
83 | |
84 | if (eft->hour >= 24) | |
85 | return false; | |
5e3fd9e5 | 86 | wtime->tm_hour = eft->hour; |
6e85bab6 JB |
87 | |
88 | if (!eft->day || eft->day > 31) | |
89 | return false; | |
5e3fd9e5 | 90 | wtime->tm_mday = eft->day; |
6e85bab6 JB |
91 | |
92 | if (!eft->month || eft->month > 12) | |
93 | return false; | |
5e3fd9e5 | 94 | wtime->tm_mon = eft->month - 1; |
5e3fd9e5 | 95 | |
b2bd2370 | 96 | if (eft->year < 1900 || eft->year > 9999) |
6e85bab6 | 97 | return false; |
b2bd2370 | 98 | wtime->tm_year = eft->year - 1900; |
5e3fd9e5 | 99 | |
100 | /* day in the year [1-365]*/ | |
101 | wtime->tm_yday = compute_yday(eft); | |
102 | ||
b2bd2370 AB |
103 | /* day of the week [0-6], Sunday=0 */ |
104 | wtime->tm_wday = compute_wday(eft, wtime->tm_yday); | |
5e3fd9e5 | 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 | } | |
6e85bab6 JB |
116 | |
117 | return true; | |
5e3fd9e5 | 118 | } |
119 | ||
120 | static 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 | ||
6e85bab6 JB |
134 | if (!convert_from_efi_time(&eft, &wkalrm->time)) |
135 | return -EIO; | |
5e3fd9e5 | 136 | |
137 | return rtc_valid_tm(&wkalrm->time); | |
138 | } | |
139 | ||
140 | static 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 | ||
34650f9e | 157 | dev_warn(dev, "write status is %d\n", (int)status); |
5e3fd9e5 | 158 | |
159 | return status == EFI_SUCCESS ? 0 : -EINVAL; | |
160 | } | |
161 | ||
162 | static 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 */ | |
34650f9e | 172 | dev_err(dev, "can't read time\n"); |
5e3fd9e5 | 173 | return -EINVAL; |
174 | } | |
175 | ||
6e85bab6 JB |
176 | if (!convert_from_efi_time(&eft, tm)) |
177 | return -EIO; | |
5e3fd9e5 | 178 | |
179 | return rtc_valid_tm(tm); | |
180 | } | |
181 | ||
182 | static 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 | ||
194 | static const struct rtc_class_ops efi_rtc_ops = { | |
195 | .read_time = efi_read_time, | |
196 | .set_time = efi_set_time, | |
197 | .read_alarm = efi_read_alarm, | |
198 | .set_alarm = efi_set_alarm, | |
199 | }; | |
200 | ||
201 | static int __init efi_rtc_probe(struct platform_device *dev) | |
202 | { | |
203 | struct rtc_device *rtc; | |
204 | ||
6ae15b0e | 205 | rtc = devm_rtc_device_register(&dev->dev, "rtc-efi", &efi_rtc_ops, |
5e3fd9e5 | 206 | THIS_MODULE); |
207 | if (IS_ERR(rtc)) | |
208 | return PTR_ERR(rtc); | |
209 | ||
822a0279 | 210 | rtc->uie_unsupported = 1; |
5e3fd9e5 | 211 | platform_set_drvdata(dev, rtc); |
212 | ||
213 | return 0; | |
214 | } | |
215 | ||
5e3fd9e5 | 216 | static struct platform_driver efi_rtc_driver = { |
217 | .driver = { | |
218 | .name = "rtc-efi", | |
5e3fd9e5 | 219 | }, |
5e3fd9e5 | 220 | }; |
221 | ||
52c6ecbc | 222 | module_platform_driver_probe(efi_rtc_driver, efi_rtc_probe); |
5e3fd9e5 | 223 | |
451ff6d4 | 224 | MODULE_ALIAS("platform:rtc-efi"); |
37563e5e | 225 | MODULE_AUTHOR("dann frazier <dannf@dannf.org>"); |
5e3fd9e5 | 226 | MODULE_LICENSE("GPL"); |
227 | MODULE_DESCRIPTION("EFI RTC driver"); | |
3f71f6da | 228 | MODULE_ALIAS("platform:rtc-efi"); |