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1da177e4 LT |
1 | /* |
2 | * EFI Time Services Driver for Linux | |
3 | * | |
4 | * Copyright (C) 1999 Hewlett-Packard Co | |
5 | * Copyright (C) 1999 Stephane Eranian <eranian@hpl.hp.com> | |
6 | * | |
7 | * Based on skeleton from the drivers/char/rtc.c driver by P. Gortmaker | |
8 | * | |
9 | * This code provides an architected & portable interface to the real time | |
10 | * clock by using EFI instead of direct bit fiddling. The functionalities are | |
11 | * quite different from the rtc.c driver. The only way to talk to the device | |
12 | * is by using ioctl(). There is a /proc interface which provides the raw | |
13 | * information. | |
14 | * | |
15 | * Please note that we have kept the API as close as possible to the | |
16 | * legacy RTC. The standard /sbin/hwclock program should work normally | |
17 | * when used to get/set the time. | |
18 | * | |
19 | * NOTES: | |
20 | * - Locking is required for safe execution of EFI calls with regards | |
8dfba4d7 | 21 | * to interrupts and SMP. |
1da177e4 LT |
22 | * |
23 | * TODO (December 1999): | |
24 | * - provide the API to set/get the WakeUp Alarm (different from the | |
25 | * rtc.c alarm). | |
26 | * - SMP testing | |
27 | * - Add module support | |
28 | */ | |
29 | ||
1da177e4 LT |
30 | #include <linux/types.h> |
31 | #include <linux/errno.h> | |
32 | #include <linux/miscdevice.h> | |
1da177e4 LT |
33 | #include <linux/init.h> |
34 | #include <linux/rtc.h> | |
35 | #include <linux/proc_fs.h> | |
788416bc | 36 | #include <linux/seq_file.h> |
1da177e4 | 37 | #include <linux/efi.h> |
76528a42 | 38 | #include <linux/uaccess.h> |
1da177e4 | 39 | |
1da177e4 LT |
40 | |
41 | #define EFI_RTC_VERSION "0.4" | |
42 | ||
43 | #define EFI_ISDST (EFI_TIME_ADJUST_DAYLIGHT|EFI_TIME_IN_DAYLIGHT) | |
44 | /* | |
45 | * EFI Epoch is 1/1/1998 | |
46 | */ | |
47 | #define EFI_RTC_EPOCH 1998 | |
48 | ||
49 | static DEFINE_SPINLOCK(efi_rtc_lock); | |
50 | ||
76528a42 AC |
51 | static long efi_rtc_ioctl(struct file *file, unsigned int cmd, |
52 | unsigned long arg); | |
1da177e4 LT |
53 | |
54 | #define is_leap(year) \ | |
55 | ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0)) | |
56 | ||
57 | static const unsigned short int __mon_yday[2][13] = | |
58 | { | |
59 | /* Normal years. */ | |
60 | { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 }, | |
61 | /* Leap years. */ | |
62 | { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 } | |
63 | }; | |
64 | ||
65 | /* | |
66 | * returns day of the year [0-365] | |
67 | */ | |
68 | static inline int | |
69 | compute_yday(efi_time_t *eft) | |
70 | { | |
71 | /* efi_time_t.month is in the [1-12] so, we need -1 */ | |
72 | return __mon_yday[is_leap(eft->year)][eft->month-1]+ eft->day -1; | |
73 | } | |
74 | /* | |
75 | * returns day of the week [0-6] 0=Sunday | |
76 | * | |
77 | * Don't try to provide a year that's before 1998, please ! | |
78 | */ | |
79 | static int | |
80 | compute_wday(efi_time_t *eft) | |
81 | { | |
82 | int y; | |
83 | int ndays = 0; | |
84 | ||
85 | if ( eft->year < 1998 ) { | |
86 | printk(KERN_ERR "efirtc: EFI year < 1998, invalid date\n"); | |
87 | return -1; | |
88 | } | |
89 | ||
90 | for(y=EFI_RTC_EPOCH; y < eft->year; y++ ) { | |
91 | ndays += 365 + (is_leap(y) ? 1 : 0); | |
92 | } | |
93 | ndays += compute_yday(eft); | |
94 | ||
95 | /* | |
96 | * 4=1/1/1998 was a Thursday | |
97 | */ | |
98 | return (ndays + 4) % 7; | |
99 | } | |
100 | ||
101 | static void | |
102 | convert_to_efi_time(struct rtc_time *wtime, efi_time_t *eft) | |
103 | { | |
104 | ||
105 | eft->year = wtime->tm_year + 1900; | |
106 | eft->month = wtime->tm_mon + 1; | |
107 | eft->day = wtime->tm_mday; | |
108 | eft->hour = wtime->tm_hour; | |
109 | eft->minute = wtime->tm_min; | |
110 | eft->second = wtime->tm_sec; | |
111 | eft->nanosecond = 0; | |
112 | eft->daylight = wtime->tm_isdst ? EFI_ISDST: 0; | |
113 | eft->timezone = EFI_UNSPECIFIED_TIMEZONE; | |
114 | } | |
115 | ||
116 | static void | |
117 | convert_from_efi_time(efi_time_t *eft, struct rtc_time *wtime) | |
118 | { | |
119 | memset(wtime, 0, sizeof(*wtime)); | |
120 | wtime->tm_sec = eft->second; | |
121 | wtime->tm_min = eft->minute; | |
122 | wtime->tm_hour = eft->hour; | |
123 | wtime->tm_mday = eft->day; | |
124 | wtime->tm_mon = eft->month - 1; | |
125 | wtime->tm_year = eft->year - 1900; | |
126 | ||
127 | /* day of the week [0-6], Sunday=0 */ | |
128 | wtime->tm_wday = compute_wday(eft); | |
129 | ||
130 | /* day in the year [1-365]*/ | |
131 | wtime->tm_yday = compute_yday(eft); | |
132 | ||
133 | ||
134 | switch (eft->daylight & EFI_ISDST) { | |
135 | case EFI_ISDST: | |
136 | wtime->tm_isdst = 1; | |
137 | break; | |
138 | case EFI_TIME_ADJUST_DAYLIGHT: | |
139 | wtime->tm_isdst = 0; | |
140 | break; | |
141 | default: | |
142 | wtime->tm_isdst = -1; | |
143 | } | |
144 | } | |
145 | ||
76528a42 AC |
146 | static long efi_rtc_ioctl(struct file *file, unsigned int cmd, |
147 | unsigned long arg) | |
1da177e4 LT |
148 | { |
149 | ||
150 | efi_status_t status; | |
151 | unsigned long flags; | |
152 | efi_time_t eft; | |
153 | efi_time_cap_t cap; | |
154 | struct rtc_time wtime; | |
155 | struct rtc_wkalrm __user *ewp; | |
156 | unsigned char enabled, pending; | |
157 | ||
158 | switch (cmd) { | |
159 | case RTC_UIE_ON: | |
160 | case RTC_UIE_OFF: | |
161 | case RTC_PIE_ON: | |
162 | case RTC_PIE_OFF: | |
163 | case RTC_AIE_ON: | |
164 | case RTC_AIE_OFF: | |
165 | case RTC_ALM_SET: | |
166 | case RTC_ALM_READ: | |
167 | case RTC_IRQP_READ: | |
168 | case RTC_IRQP_SET: | |
169 | case RTC_EPOCH_READ: | |
170 | case RTC_EPOCH_SET: | |
171 | return -EINVAL; | |
172 | ||
173 | case RTC_RD_TIME: | |
1da177e4 LT |
174 | spin_lock_irqsave(&efi_rtc_lock, flags); |
175 | ||
176 | status = efi.get_time(&eft, &cap); | |
177 | ||
178 | spin_unlock_irqrestore(&efi_rtc_lock,flags); | |
a5ee6dc9 | 179 | |
1da177e4 LT |
180 | if (status != EFI_SUCCESS) { |
181 | /* should never happen */ | |
182 | printk(KERN_ERR "efitime: can't read time\n"); | |
183 | return -EINVAL; | |
184 | } | |
185 | ||
186 | convert_from_efi_time(&eft, &wtime); | |
187 | ||
188 | return copy_to_user((void __user *)arg, &wtime, | |
189 | sizeof (struct rtc_time)) ? - EFAULT : 0; | |
190 | ||
191 | case RTC_SET_TIME: | |
192 | ||
193 | if (!capable(CAP_SYS_TIME)) return -EACCES; | |
194 | ||
195 | if (copy_from_user(&wtime, (struct rtc_time __user *)arg, | |
196 | sizeof(struct rtc_time)) ) | |
197 | return -EFAULT; | |
198 | ||
199 | convert_to_efi_time(&wtime, &eft); | |
200 | ||
201 | spin_lock_irqsave(&efi_rtc_lock, flags); | |
202 | ||
203 | status = efi.set_time(&eft); | |
204 | ||
205 | spin_unlock_irqrestore(&efi_rtc_lock,flags); | |
206 | ||
207 | return status == EFI_SUCCESS ? 0 : -EINVAL; | |
208 | ||
209 | case RTC_WKALM_SET: | |
210 | ||
211 | if (!capable(CAP_SYS_TIME)) return -EACCES; | |
212 | ||
213 | ewp = (struct rtc_wkalrm __user *)arg; | |
214 | ||
215 | if ( get_user(enabled, &ewp->enabled) | |
216 | || copy_from_user(&wtime, &ewp->time, sizeof(struct rtc_time)) ) | |
217 | return -EFAULT; | |
218 | ||
219 | convert_to_efi_time(&wtime, &eft); | |
220 | ||
221 | spin_lock_irqsave(&efi_rtc_lock, flags); | |
222 | /* | |
223 | * XXX Fixme: | |
224 | * As of EFI 0.92 with the firmware I have on my | |
225 | * machine this call does not seem to work quite | |
226 | * right | |
227 | */ | |
228 | status = efi.set_wakeup_time((efi_bool_t)enabled, &eft); | |
229 | ||
230 | spin_unlock_irqrestore(&efi_rtc_lock,flags); | |
231 | ||
232 | return status == EFI_SUCCESS ? 0 : -EINVAL; | |
233 | ||
234 | case RTC_WKALM_RD: | |
235 | ||
236 | spin_lock_irqsave(&efi_rtc_lock, flags); | |
237 | ||
238 | status = efi.get_wakeup_time((efi_bool_t *)&enabled, (efi_bool_t *)&pending, &eft); | |
239 | ||
240 | spin_unlock_irqrestore(&efi_rtc_lock,flags); | |
241 | ||
242 | if (status != EFI_SUCCESS) return -EINVAL; | |
243 | ||
244 | ewp = (struct rtc_wkalrm __user *)arg; | |
245 | ||
246 | if ( put_user(enabled, &ewp->enabled) | |
247 | || put_user(pending, &ewp->pending)) return -EFAULT; | |
248 | ||
249 | convert_from_efi_time(&eft, &wtime); | |
250 | ||
251 | return copy_to_user(&ewp->time, &wtime, | |
252 | sizeof(struct rtc_time)) ? -EFAULT : 0; | |
253 | } | |
76528a42 | 254 | return -ENOTTY; |
1da177e4 LT |
255 | } |
256 | ||
257 | /* | |
258 | * We enforce only one user at a time here with the open/close. | |
259 | * Also clear the previous interrupt data on an open, and clean | |
260 | * up things on a close. | |
261 | */ | |
262 | ||
76528a42 | 263 | static int efi_rtc_open(struct inode *inode, struct file *file) |
1da177e4 LT |
264 | { |
265 | /* | |
266 | * nothing special to do here | |
267 | * We do accept multiple open files at the same time as we | |
268 | * synchronize on the per call operation. | |
269 | */ | |
270 | return 0; | |
271 | } | |
272 | ||
76528a42 | 273 | static int efi_rtc_close(struct inode *inode, struct file *file) |
1da177e4 LT |
274 | { |
275 | return 0; | |
276 | } | |
277 | ||
278 | /* | |
279 | * The various file operations we support. | |
280 | */ | |
281 | ||
62322d25 | 282 | static const struct file_operations efi_rtc_fops = { |
1da177e4 | 283 | .owner = THIS_MODULE, |
76528a42 | 284 | .unlocked_ioctl = efi_rtc_ioctl, |
1da177e4 LT |
285 | .open = efi_rtc_open, |
286 | .release = efi_rtc_close, | |
f29627c2 | 287 | .llseek = no_llseek, |
1da177e4 LT |
288 | }; |
289 | ||
76528a42 | 290 | static struct miscdevice efi_rtc_dev= { |
1da177e4 LT |
291 | EFI_RTC_MINOR, |
292 | "efirtc", | |
293 | &efi_rtc_fops | |
294 | }; | |
295 | ||
296 | /* | |
297 | * We export RAW EFI information to /proc/driver/efirtc | |
298 | */ | |
788416bc | 299 | static int efi_rtc_proc_show(struct seq_file *m, void *v) |
1da177e4 LT |
300 | { |
301 | efi_time_t eft, alm; | |
302 | efi_time_cap_t cap; | |
1da177e4 LT |
303 | efi_bool_t enabled, pending; |
304 | unsigned long flags; | |
305 | ||
306 | memset(&eft, 0, sizeof(eft)); | |
307 | memset(&alm, 0, sizeof(alm)); | |
308 | memset(&cap, 0, sizeof(cap)); | |
309 | ||
310 | spin_lock_irqsave(&efi_rtc_lock, flags); | |
311 | ||
312 | efi.get_time(&eft, &cap); | |
313 | efi.get_wakeup_time(&enabled, &pending, &alm); | |
314 | ||
315 | spin_unlock_irqrestore(&efi_rtc_lock,flags); | |
316 | ||
788416bc DH |
317 | seq_printf(m, |
318 | "Time : %u:%u:%u.%09u\n" | |
319 | "Date : %u-%u-%u\n" | |
320 | "Daylight : %u\n", | |
321 | eft.hour, eft.minute, eft.second, eft.nanosecond, | |
322 | eft.year, eft.month, eft.day, | |
323 | eft.daylight); | |
1da177e4 LT |
324 | |
325 | if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE) | |
788416bc | 326 | seq_puts(m, "Timezone : unspecified\n"); |
1da177e4 LT |
327 | else |
328 | /* XXX fixme: convert to string? */ | |
788416bc | 329 | seq_printf(m, "Timezone : %u\n", eft.timezone); |
1da177e4 LT |
330 | |
331 | ||
788416bc DH |
332 | seq_printf(m, |
333 | "Alarm Time : %u:%u:%u.%09u\n" | |
334 | "Alarm Date : %u-%u-%u\n" | |
335 | "Alarm Daylight : %u\n" | |
336 | "Enabled : %s\n" | |
337 | "Pending : %s\n", | |
338 | alm.hour, alm.minute, alm.second, alm.nanosecond, | |
339 | alm.year, alm.month, alm.day, | |
340 | alm.daylight, | |
341 | enabled == 1 ? "yes" : "no", | |
342 | pending == 1 ? "yes" : "no"); | |
1da177e4 LT |
343 | |
344 | if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE) | |
788416bc | 345 | seq_puts(m, "Timezone : unspecified\n"); |
1da177e4 LT |
346 | else |
347 | /* XXX fixme: convert to string? */ | |
788416bc | 348 | seq_printf(m, "Timezone : %u\n", alm.timezone); |
1da177e4 LT |
349 | |
350 | /* | |
351 | * now prints the capabilities | |
352 | */ | |
788416bc DH |
353 | seq_printf(m, |
354 | "Resolution : %u\n" | |
355 | "Accuracy : %u\n" | |
356 | "SetstoZero : %u\n", | |
357 | cap.resolution, cap.accuracy, cap.sets_to_zero); | |
1da177e4 | 358 | |
788416bc | 359 | return 0; |
1da177e4 LT |
360 | } |
361 | ||
788416bc | 362 | static int efi_rtc_proc_open(struct inode *inode, struct file *file) |
1da177e4 | 363 | { |
788416bc | 364 | return single_open(file, efi_rtc_proc_show, NULL); |
1da177e4 LT |
365 | } |
366 | ||
788416bc DH |
367 | static const struct file_operations efi_rtc_proc_fops = { |
368 | .open = efi_rtc_proc_open, | |
369 | .read = seq_read, | |
370 | .llseek = seq_lseek, | |
2e7718cf | 371 | .release = single_release, |
788416bc DH |
372 | }; |
373 | ||
1da177e4 LT |
374 | static int __init |
375 | efi_rtc_init(void) | |
376 | { | |
377 | int ret; | |
378 | struct proc_dir_entry *dir; | |
379 | ||
380 | printk(KERN_INFO "EFI Time Services Driver v%s\n", EFI_RTC_VERSION); | |
381 | ||
382 | ret = misc_register(&efi_rtc_dev); | |
383 | if (ret) { | |
384 | printk(KERN_ERR "efirtc: can't misc_register on minor=%d\n", | |
385 | EFI_RTC_MINOR); | |
386 | return ret; | |
387 | } | |
388 | ||
788416bc | 389 | dir = proc_create("driver/efirtc", 0, NULL, &efi_rtc_proc_fops); |
1da177e4 LT |
390 | if (dir == NULL) { |
391 | printk(KERN_ERR "efirtc: can't create /proc/driver/efirtc.\n"); | |
392 | misc_deregister(&efi_rtc_dev); | |
393 | return -1; | |
394 | } | |
395 | return 0; | |
396 | } | |
9b7ebe01 | 397 | device_initcall(efi_rtc_init); |
1da177e4 | 398 | |
9b7ebe01 | 399 | /* |
1da177e4 | 400 | MODULE_LICENSE("GPL"); |
9b7ebe01 | 401 | */ |