Version:  2.0.40 2.2.26 2.4.37 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16

Linux/drivers/rtc/rtc-efi.c

  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  */
 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 */
 38         return rtc_year_days(eft->day, 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  */
 45 static int
 46 compute_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 
 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;
 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 
 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 
147         dev_warn(dev, "write status is %d\n", (int)status);
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 */
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 
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 
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 
204 static struct platform_driver efi_rtc_driver = {
205         .driver = {
206                 .name = "rtc-efi",
207                 .owner = THIS_MODULE,
208         },
209 };
210 
211 module_platform_driver_probe(efi_rtc_driver, efi_rtc_probe);
212 
213 MODULE_AUTHOR("dann frazier <dannf@hp.com>");
214 MODULE_LICENSE("GPL");
215 MODULE_DESCRIPTION("EFI RTC driver");
216 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us