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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 | * | |
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 | ||
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) | |
27 | /* | |
28 | * EFI Epoch is 1/1/1998 | |
29 | */ | |
30 | #define EFI_RTC_EPOCH 1998 | |
31 | ||
32 | /* | |
33 | * returns day of the year [0-365] | |
34 | */ | |
35 | static inline int | |
36 | compute_yday(efi_time_t *eft) | |
37 | { | |
38 | /* efi_time_t.month is in the [1-12] so, we need -1 */ | |
809d9627 | 39 | return rtc_year_days(eft->day, eft->month - 1, eft->year); |
5e3fd9e5 | 40 | } |
41 | /* | |
42 | * returns day of the week [0-6] 0=Sunday | |
43 | * | |
44 | * Don't try to provide a year that's before 1998, please ! | |
45 | */ | |
46 | static int | |
47 | compute_wday(efi_time_t *eft) | |
48 | { | |
49 | int y; | |
50 | int ndays = 0; | |
51 | ||
6e85bab6 JB |
52 | if (eft->year < EFI_RTC_EPOCH) { |
53 | pr_err("EFI year < " __stringify(EFI_RTC_EPOCH) ", invalid date\n"); | |
5e3fd9e5 | 54 | return -1; |
55 | } | |
56 | ||
57 | for (y = EFI_RTC_EPOCH; y < eft->year; y++) | |
58 | ndays += 365 + (is_leap_year(y) ? 1 : 0); | |
59 | ||
60 | ndays += compute_yday(eft); | |
61 | ||
62 | /* | |
63 | * 4=1/1/1998 was a Thursday | |
64 | */ | |
65 | return (ndays + 4) % 7; | |
66 | } | |
67 | ||
68 | static void | |
69 | convert_to_efi_time(struct rtc_time *wtime, efi_time_t *eft) | |
70 | { | |
71 | eft->year = wtime->tm_year + 1900; | |
72 | eft->month = wtime->tm_mon + 1; | |
73 | eft->day = wtime->tm_mday; | |
74 | eft->hour = wtime->tm_hour; | |
75 | eft->minute = wtime->tm_min; | |
34650f9e | 76 | eft->second = wtime->tm_sec; |
5e3fd9e5 | 77 | eft->nanosecond = 0; |
78 | eft->daylight = wtime->tm_isdst ? EFI_ISDST : 0; | |
79 | eft->timezone = EFI_UNSPECIFIED_TIMEZONE; | |
80 | } | |
81 | ||
6e85bab6 | 82 | static bool |
5e3fd9e5 | 83 | convert_from_efi_time(efi_time_t *eft, struct rtc_time *wtime) |
84 | { | |
85 | memset(wtime, 0, sizeof(*wtime)); | |
6e85bab6 JB |
86 | |
87 | if (eft->second >= 60) | |
88 | return false; | |
5e3fd9e5 | 89 | wtime->tm_sec = eft->second; |
6e85bab6 JB |
90 | |
91 | if (eft->minute >= 60) | |
92 | return false; | |
5e3fd9e5 | 93 | wtime->tm_min = eft->minute; |
6e85bab6 JB |
94 | |
95 | if (eft->hour >= 24) | |
96 | return false; | |
5e3fd9e5 | 97 | wtime->tm_hour = eft->hour; |
6e85bab6 JB |
98 | |
99 | if (!eft->day || eft->day > 31) | |
100 | return false; | |
5e3fd9e5 | 101 | wtime->tm_mday = eft->day; |
6e85bab6 JB |
102 | |
103 | if (!eft->month || eft->month > 12) | |
104 | return false; | |
5e3fd9e5 | 105 | wtime->tm_mon = eft->month - 1; |
106 | wtime->tm_year = eft->year - 1900; | |
107 | ||
108 | /* day of the week [0-6], Sunday=0 */ | |
109 | wtime->tm_wday = compute_wday(eft); | |
6e85bab6 JB |
110 | if (wtime->tm_wday < 0) |
111 | return false; | |
5e3fd9e5 | 112 | |
113 | /* day in the year [1-365]*/ | |
114 | wtime->tm_yday = compute_yday(eft); | |
115 | ||
116 | ||
117 | switch (eft->daylight & EFI_ISDST) { | |
118 | case EFI_ISDST: | |
119 | wtime->tm_isdst = 1; | |
120 | break; | |
121 | case EFI_TIME_ADJUST_DAYLIGHT: | |
122 | wtime->tm_isdst = 0; | |
123 | break; | |
124 | default: | |
125 | wtime->tm_isdst = -1; | |
126 | } | |
6e85bab6 JB |
127 | |
128 | return true; | |
5e3fd9e5 | 129 | } |
130 | ||
131 | static int efi_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm) | |
132 | { | |
133 | efi_time_t eft; | |
134 | efi_status_t status; | |
135 | ||
136 | /* | |
137 | * As of EFI v1.10, this call always returns an unsupported status | |
138 | */ | |
139 | status = efi.get_wakeup_time((efi_bool_t *)&wkalrm->enabled, | |
140 | (efi_bool_t *)&wkalrm->pending, &eft); | |
141 | ||
142 | if (status != EFI_SUCCESS) | |
143 | return -EINVAL; | |
144 | ||
6e85bab6 JB |
145 | if (!convert_from_efi_time(&eft, &wkalrm->time)) |
146 | return -EIO; | |
5e3fd9e5 | 147 | |
148 | return rtc_valid_tm(&wkalrm->time); | |
149 | } | |
150 | ||
151 | static int efi_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm) | |
152 | { | |
153 | efi_time_t eft; | |
154 | efi_status_t status; | |
155 | ||
156 | convert_to_efi_time(&wkalrm->time, &eft); | |
157 | ||
158 | /* | |
159 | * XXX Fixme: | |
160 | * As of EFI 0.92 with the firmware I have on my | |
161 | * machine this call does not seem to work quite | |
162 | * right | |
163 | * | |
164 | * As of v1.10, this call always returns an unsupported status | |
165 | */ | |
166 | status = efi.set_wakeup_time((efi_bool_t)wkalrm->enabled, &eft); | |
167 | ||
34650f9e | 168 | dev_warn(dev, "write status is %d\n", (int)status); |
5e3fd9e5 | 169 | |
170 | return status == EFI_SUCCESS ? 0 : -EINVAL; | |
171 | } | |
172 | ||
173 | static int efi_read_time(struct device *dev, struct rtc_time *tm) | |
174 | { | |
175 | efi_status_t status; | |
176 | efi_time_t eft; | |
177 | efi_time_cap_t cap; | |
178 | ||
179 | status = efi.get_time(&eft, &cap); | |
180 | ||
181 | if (status != EFI_SUCCESS) { | |
182 | /* should never happen */ | |
34650f9e | 183 | dev_err(dev, "can't read time\n"); |
5e3fd9e5 | 184 | return -EINVAL; |
185 | } | |
186 | ||
6e85bab6 JB |
187 | if (!convert_from_efi_time(&eft, tm)) |
188 | return -EIO; | |
5e3fd9e5 | 189 | |
190 | return rtc_valid_tm(tm); | |
191 | } | |
192 | ||
193 | static int efi_set_time(struct device *dev, struct rtc_time *tm) | |
194 | { | |
195 | efi_status_t status; | |
196 | efi_time_t eft; | |
197 | ||
198 | convert_to_efi_time(tm, &eft); | |
199 | ||
200 | status = efi.set_time(&eft); | |
201 | ||
202 | return status == EFI_SUCCESS ? 0 : -EINVAL; | |
203 | } | |
204 | ||
205 | static const struct rtc_class_ops efi_rtc_ops = { | |
206 | .read_time = efi_read_time, | |
207 | .set_time = efi_set_time, | |
208 | .read_alarm = efi_read_alarm, | |
209 | .set_alarm = efi_set_alarm, | |
210 | }; | |
211 | ||
212 | static int __init efi_rtc_probe(struct platform_device *dev) | |
213 | { | |
214 | struct rtc_device *rtc; | |
215 | ||
6ae15b0e | 216 | rtc = devm_rtc_device_register(&dev->dev, "rtc-efi", &efi_rtc_ops, |
5e3fd9e5 | 217 | THIS_MODULE); |
218 | if (IS_ERR(rtc)) | |
219 | return PTR_ERR(rtc); | |
220 | ||
221 | platform_set_drvdata(dev, rtc); | |
222 | ||
223 | return 0; | |
224 | } | |
225 | ||
5e3fd9e5 | 226 | static struct platform_driver efi_rtc_driver = { |
227 | .driver = { | |
228 | .name = "rtc-efi", | |
229 | .owner = THIS_MODULE, | |
230 | }, | |
5e3fd9e5 | 231 | }; |
232 | ||
52c6ecbc | 233 | module_platform_driver_probe(efi_rtc_driver, efi_rtc_probe); |
5e3fd9e5 | 234 | |
451ff6d4 | 235 | MODULE_ALIAS("platform:rtc-efi"); |
5e3fd9e5 | 236 | MODULE_AUTHOR("dann frazier <dannf@hp.com>"); |
237 | MODULE_LICENSE("GPL"); | |
238 | MODULE_DESCRIPTION("EFI RTC driver"); |