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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 | ||
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 | */ | |
32 | static inline int | |
33 | compute_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 | */ | |
43 | static int | |
44 | compute_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 | ||
65 | static void | |
66 | convert_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 | ||
79 | static void | |
80 | convert_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 | ||
109 | static 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 | ||
128 | static 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 | ||
150 | static 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 | ||
169 | static 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 | ||
181 | static 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 | ||
188 | static 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 | ||
202 | static 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 | ||
211 | static 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 | ||
220 | static int __init efi_rtc_init(void) | |
221 | { | |
222 | return platform_driver_probe(&efi_rtc_driver, efi_rtc_probe); | |
223 | } | |
224 | ||
225 | static void __exit efi_rtc_exit(void) | |
226 | { | |
227 | platform_driver_unregister(&efi_rtc_driver); | |
228 | } | |
229 | ||
230 | module_init(efi_rtc_init); | |
231 | module_exit(efi_rtc_exit); | |
232 | ||
233 | MODULE_AUTHOR("dann frazier <dannf@hp.com>"); | |
234 | MODULE_LICENSE("GPL"); | |
235 | MODULE_DESCRIPTION("EFI RTC driver"); |