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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> | |
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 | */ | |
34 | static inline int | |
35 | compute_yday(efi_time_t *eft) | |
36 | { | |
37 | /* efi_time_t.month is in the [1-12] so, we need -1 */ | |
809d9627 | 38 | return rtc_year_days(eft->day, eft->month - 1, eft->year); |
5e3fd9e5 | 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 | */ | |
45 | static int | |
46 | compute_wday(efi_time_t *eft) | |
47 | { | |
48 | int y; | |
49 | int ndays = 0; | |
50 | ||
51 | if (eft->year < 1998) { | |
34650f9e | 52 | pr_err("EFI year < 1998, invalid date\n"); |
5e3fd9e5 | 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 | ||
67 | static void | |
68 | convert_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; | |
34650f9e | 75 | eft->second = wtime->tm_sec; |
5e3fd9e5 | 76 | eft->nanosecond = 0; |
77 | eft->daylight = wtime->tm_isdst ? EFI_ISDST : 0; | |
78 | eft->timezone = EFI_UNSPECIFIED_TIMEZONE; | |
79 | } | |
80 | ||
81 | static void | |
82 | convert_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 | ||
111 | static 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 | ||
130 | static 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 | ||
34650f9e | 147 | dev_warn(dev, "write status is %d\n", (int)status); |
5e3fd9e5 | 148 | |
149 | return status == EFI_SUCCESS ? 0 : -EINVAL; | |
150 | } | |
151 | ||
152 | static 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 */ | |
34650f9e | 162 | dev_err(dev, "can't read time\n"); |
5e3fd9e5 | 163 | return -EINVAL; |
164 | } | |
165 | ||
166 | convert_from_efi_time(&eft, tm); | |
167 | ||
168 | return rtc_valid_tm(tm); | |
169 | } | |
170 | ||
171 | static 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 | ||
183 | static 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 | ||
190 | static int __init efi_rtc_probe(struct platform_device *dev) | |
191 | { | |
192 | struct rtc_device *rtc; | |
193 | ||
6ae15b0e | 194 | rtc = devm_rtc_device_register(&dev->dev, "rtc-efi", &efi_rtc_ops, |
5e3fd9e5 | 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 | ||
5e3fd9e5 | 204 | static struct platform_driver efi_rtc_driver = { |
205 | .driver = { | |
206 | .name = "rtc-efi", | |
207 | .owner = THIS_MODULE, | |
208 | }, | |
5e3fd9e5 | 209 | }; |
210 | ||
52c6ecbc | 211 | module_platform_driver_probe(efi_rtc_driver, efi_rtc_probe); |
5e3fd9e5 | 212 | |
213 | MODULE_AUTHOR("dann frazier <dannf@hp.com>"); | |
214 | MODULE_LICENSE("GPL"); | |
215 | MODULE_DESCRIPTION("EFI RTC driver"); |