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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> | |
33 | #include <linux/module.h> | |
34 | #include <linux/init.h> | |
35 | #include <linux/rtc.h> | |
36 | #include <linux/proc_fs.h> | |
37 | #include <linux/efi.h> | |
76528a42 | 38 | #include <linux/uaccess.h> |
1da177e4 | 39 | |
1da177e4 LT |
40 | #include <asm/system.h> |
41 | ||
42 | #define EFI_RTC_VERSION "0.4" | |
43 | ||
44 | #define EFI_ISDST (EFI_TIME_ADJUST_DAYLIGHT|EFI_TIME_IN_DAYLIGHT) | |
45 | /* | |
46 | * EFI Epoch is 1/1/1998 | |
47 | */ | |
48 | #define EFI_RTC_EPOCH 1998 | |
49 | ||
50 | static DEFINE_SPINLOCK(efi_rtc_lock); | |
51 | ||
76528a42 AC |
52 | static long efi_rtc_ioctl(struct file *file, unsigned int cmd, |
53 | unsigned long arg); | |
1da177e4 LT |
54 | |
55 | #define is_leap(year) \ | |
56 | ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0)) | |
57 | ||
58 | static const unsigned short int __mon_yday[2][13] = | |
59 | { | |
60 | /* Normal years. */ | |
61 | { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 }, | |
62 | /* Leap years. */ | |
63 | { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 } | |
64 | }; | |
65 | ||
66 | /* | |
67 | * returns day of the year [0-365] | |
68 | */ | |
69 | static inline int | |
70 | compute_yday(efi_time_t *eft) | |
71 | { | |
72 | /* efi_time_t.month is in the [1-12] so, we need -1 */ | |
73 | return __mon_yday[is_leap(eft->year)][eft->month-1]+ eft->day -1; | |
74 | } | |
75 | /* | |
76 | * returns day of the week [0-6] 0=Sunday | |
77 | * | |
78 | * Don't try to provide a year that's before 1998, please ! | |
79 | */ | |
80 | static int | |
81 | compute_wday(efi_time_t *eft) | |
82 | { | |
83 | int y; | |
84 | int ndays = 0; | |
85 | ||
86 | if ( eft->year < 1998 ) { | |
87 | printk(KERN_ERR "efirtc: EFI year < 1998, invalid date\n"); | |
88 | return -1; | |
89 | } | |
90 | ||
91 | for(y=EFI_RTC_EPOCH; y < eft->year; y++ ) { | |
92 | ndays += 365 + (is_leap(y) ? 1 : 0); | |
93 | } | |
94 | ndays += compute_yday(eft); | |
95 | ||
96 | /* | |
97 | * 4=1/1/1998 was a Thursday | |
98 | */ | |
99 | return (ndays + 4) % 7; | |
100 | } | |
101 | ||
102 | static void | |
103 | convert_to_efi_time(struct rtc_time *wtime, efi_time_t *eft) | |
104 | { | |
105 | ||
106 | eft->year = wtime->tm_year + 1900; | |
107 | eft->month = wtime->tm_mon + 1; | |
108 | eft->day = wtime->tm_mday; | |
109 | eft->hour = wtime->tm_hour; | |
110 | eft->minute = wtime->tm_min; | |
111 | eft->second = wtime->tm_sec; | |
112 | eft->nanosecond = 0; | |
113 | eft->daylight = wtime->tm_isdst ? EFI_ISDST: 0; | |
114 | eft->timezone = EFI_UNSPECIFIED_TIMEZONE; | |
115 | } | |
116 | ||
117 | static void | |
118 | convert_from_efi_time(efi_time_t *eft, struct rtc_time *wtime) | |
119 | { | |
120 | memset(wtime, 0, sizeof(*wtime)); | |
121 | wtime->tm_sec = eft->second; | |
122 | wtime->tm_min = eft->minute; | |
123 | wtime->tm_hour = eft->hour; | |
124 | wtime->tm_mday = eft->day; | |
125 | wtime->tm_mon = eft->month - 1; | |
126 | wtime->tm_year = eft->year - 1900; | |
127 | ||
128 | /* day of the week [0-6], Sunday=0 */ | |
129 | wtime->tm_wday = compute_wday(eft); | |
130 | ||
131 | /* day in the year [1-365]*/ | |
132 | wtime->tm_yday = compute_yday(eft); | |
133 | ||
134 | ||
135 | switch (eft->daylight & EFI_ISDST) { | |
136 | case EFI_ISDST: | |
137 | wtime->tm_isdst = 1; | |
138 | break; | |
139 | case EFI_TIME_ADJUST_DAYLIGHT: | |
140 | wtime->tm_isdst = 0; | |
141 | break; | |
142 | default: | |
143 | wtime->tm_isdst = -1; | |
144 | } | |
145 | } | |
146 | ||
76528a42 AC |
147 | static long efi_rtc_ioctl(struct file *file, unsigned int cmd, |
148 | unsigned long arg) | |
1da177e4 LT |
149 | { |
150 | ||
151 | efi_status_t status; | |
152 | unsigned long flags; | |
153 | efi_time_t eft; | |
154 | efi_time_cap_t cap; | |
155 | struct rtc_time wtime; | |
156 | struct rtc_wkalrm __user *ewp; | |
157 | unsigned char enabled, pending; | |
158 | ||
159 | switch (cmd) { | |
160 | case RTC_UIE_ON: | |
161 | case RTC_UIE_OFF: | |
162 | case RTC_PIE_ON: | |
163 | case RTC_PIE_OFF: | |
164 | case RTC_AIE_ON: | |
165 | case RTC_AIE_OFF: | |
166 | case RTC_ALM_SET: | |
167 | case RTC_ALM_READ: | |
168 | case RTC_IRQP_READ: | |
169 | case RTC_IRQP_SET: | |
170 | case RTC_EPOCH_READ: | |
171 | case RTC_EPOCH_SET: | |
172 | return -EINVAL; | |
173 | ||
174 | case RTC_RD_TIME: | |
1da177e4 LT |
175 | spin_lock_irqsave(&efi_rtc_lock, flags); |
176 | ||
177 | status = efi.get_time(&eft, &cap); | |
178 | ||
179 | spin_unlock_irqrestore(&efi_rtc_lock,flags); | |
a5ee6dc9 | 180 | |
1da177e4 LT |
181 | if (status != EFI_SUCCESS) { |
182 | /* should never happen */ | |
183 | printk(KERN_ERR "efitime: can't read time\n"); | |
184 | return -EINVAL; | |
185 | } | |
186 | ||
187 | convert_from_efi_time(&eft, &wtime); | |
188 | ||
189 | return copy_to_user((void __user *)arg, &wtime, | |
190 | sizeof (struct rtc_time)) ? - EFAULT : 0; | |
191 | ||
192 | case RTC_SET_TIME: | |
193 | ||
194 | if (!capable(CAP_SYS_TIME)) return -EACCES; | |
195 | ||
196 | if (copy_from_user(&wtime, (struct rtc_time __user *)arg, | |
197 | sizeof(struct rtc_time)) ) | |
198 | return -EFAULT; | |
199 | ||
200 | convert_to_efi_time(&wtime, &eft); | |
201 | ||
202 | spin_lock_irqsave(&efi_rtc_lock, flags); | |
203 | ||
204 | status = efi.set_time(&eft); | |
205 | ||
206 | spin_unlock_irqrestore(&efi_rtc_lock,flags); | |
207 | ||
208 | return status == EFI_SUCCESS ? 0 : -EINVAL; | |
209 | ||
210 | case RTC_WKALM_SET: | |
211 | ||
212 | if (!capable(CAP_SYS_TIME)) return -EACCES; | |
213 | ||
214 | ewp = (struct rtc_wkalrm __user *)arg; | |
215 | ||
216 | if ( get_user(enabled, &ewp->enabled) | |
217 | || copy_from_user(&wtime, &ewp->time, sizeof(struct rtc_time)) ) | |
218 | return -EFAULT; | |
219 | ||
220 | convert_to_efi_time(&wtime, &eft); | |
221 | ||
222 | spin_lock_irqsave(&efi_rtc_lock, flags); | |
223 | /* | |
224 | * XXX Fixme: | |
225 | * As of EFI 0.92 with the firmware I have on my | |
226 | * machine this call does not seem to work quite | |
227 | * right | |
228 | */ | |
229 | status = efi.set_wakeup_time((efi_bool_t)enabled, &eft); | |
230 | ||
231 | spin_unlock_irqrestore(&efi_rtc_lock,flags); | |
232 | ||
233 | return status == EFI_SUCCESS ? 0 : -EINVAL; | |
234 | ||
235 | case RTC_WKALM_RD: | |
236 | ||
237 | spin_lock_irqsave(&efi_rtc_lock, flags); | |
238 | ||
239 | status = efi.get_wakeup_time((efi_bool_t *)&enabled, (efi_bool_t *)&pending, &eft); | |
240 | ||
241 | spin_unlock_irqrestore(&efi_rtc_lock,flags); | |
242 | ||
243 | if (status != EFI_SUCCESS) return -EINVAL; | |
244 | ||
245 | ewp = (struct rtc_wkalrm __user *)arg; | |
246 | ||
247 | if ( put_user(enabled, &ewp->enabled) | |
248 | || put_user(pending, &ewp->pending)) return -EFAULT; | |
249 | ||
250 | convert_from_efi_time(&eft, &wtime); | |
251 | ||
252 | return copy_to_user(&ewp->time, &wtime, | |
253 | sizeof(struct rtc_time)) ? -EFAULT : 0; | |
254 | } | |
76528a42 | 255 | return -ENOTTY; |
1da177e4 LT |
256 | } |
257 | ||
258 | /* | |
259 | * We enforce only one user at a time here with the open/close. | |
260 | * Also clear the previous interrupt data on an open, and clean | |
261 | * up things on a close. | |
262 | */ | |
263 | ||
76528a42 | 264 | static int efi_rtc_open(struct inode *inode, struct file *file) |
1da177e4 LT |
265 | { |
266 | /* | |
267 | * nothing special to do here | |
268 | * We do accept multiple open files at the same time as we | |
269 | * synchronize on the per call operation. | |
270 | */ | |
271 | return 0; | |
272 | } | |
273 | ||
76528a42 | 274 | static int efi_rtc_close(struct inode *inode, struct file *file) |
1da177e4 LT |
275 | { |
276 | return 0; | |
277 | } | |
278 | ||
279 | /* | |
280 | * The various file operations we support. | |
281 | */ | |
282 | ||
62322d25 | 283 | static const struct file_operations efi_rtc_fops = { |
1da177e4 | 284 | .owner = THIS_MODULE, |
76528a42 | 285 | .unlocked_ioctl = efi_rtc_ioctl, |
1da177e4 LT |
286 | .open = efi_rtc_open, |
287 | .release = efi_rtc_close, | |
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 | */ | |
299 | static int | |
300 | efi_rtc_get_status(char *buf) | |
301 | { | |
302 | efi_time_t eft, alm; | |
303 | efi_time_cap_t cap; | |
304 | char *p = buf; | |
305 | efi_bool_t enabled, pending; | |
306 | unsigned long flags; | |
307 | ||
308 | memset(&eft, 0, sizeof(eft)); | |
309 | memset(&alm, 0, sizeof(alm)); | |
310 | memset(&cap, 0, sizeof(cap)); | |
311 | ||
312 | spin_lock_irqsave(&efi_rtc_lock, flags); | |
313 | ||
314 | efi.get_time(&eft, &cap); | |
315 | efi.get_wakeup_time(&enabled, &pending, &alm); | |
316 | ||
317 | spin_unlock_irqrestore(&efi_rtc_lock,flags); | |
318 | ||
319 | p += sprintf(p, | |
320 | "Time : %u:%u:%u.%09u\n" | |
321 | "Date : %u-%u-%u\n" | |
322 | "Daylight : %u\n", | |
323 | eft.hour, eft.minute, eft.second, eft.nanosecond, | |
324 | eft.year, eft.month, eft.day, | |
325 | eft.daylight); | |
326 | ||
327 | if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE) | |
328 | p += sprintf(p, "Timezone : unspecified\n"); | |
329 | else | |
330 | /* XXX fixme: convert to string? */ | |
331 | p += sprintf(p, "Timezone : %u\n", eft.timezone); | |
332 | ||
333 | ||
334 | p += sprintf(p, | |
335 | "Alarm Time : %u:%u:%u.%09u\n" | |
336 | "Alarm Date : %u-%u-%u\n" | |
337 | "Alarm Daylight : %u\n" | |
338 | "Enabled : %s\n" | |
339 | "Pending : %s\n", | |
340 | alm.hour, alm.minute, alm.second, alm.nanosecond, | |
341 | alm.year, alm.month, alm.day, | |
342 | alm.daylight, | |
343 | enabled == 1 ? "yes" : "no", | |
344 | pending == 1 ? "yes" : "no"); | |
345 | ||
346 | if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE) | |
347 | p += sprintf(p, "Timezone : unspecified\n"); | |
348 | else | |
349 | /* XXX fixme: convert to string? */ | |
350 | p += sprintf(p, "Timezone : %u\n", alm.timezone); | |
351 | ||
352 | /* | |
353 | * now prints the capabilities | |
354 | */ | |
355 | p += sprintf(p, | |
356 | "Resolution : %u\n" | |
357 | "Accuracy : %u\n" | |
358 | "SetstoZero : %u\n", | |
359 | cap.resolution, cap.accuracy, cap.sets_to_zero); | |
360 | ||
361 | return p - buf; | |
362 | } | |
363 | ||
364 | static int | |
365 | efi_rtc_read_proc(char *page, char **start, off_t off, | |
366 | int count, int *eof, void *data) | |
367 | { | |
368 | int len = efi_rtc_get_status(page); | |
369 | if (len <= off+count) *eof = 1; | |
370 | *start = page + off; | |
371 | len -= off; | |
372 | if (len>count) len = count; | |
373 | if (len<0) len = 0; | |
374 | return len; | |
375 | } | |
376 | ||
377 | static int __init | |
378 | efi_rtc_init(void) | |
379 | { | |
380 | int ret; | |
381 | struct proc_dir_entry *dir; | |
382 | ||
383 | printk(KERN_INFO "EFI Time Services Driver v%s\n", EFI_RTC_VERSION); | |
384 | ||
385 | ret = misc_register(&efi_rtc_dev); | |
386 | if (ret) { | |
387 | printk(KERN_ERR "efirtc: can't misc_register on minor=%d\n", | |
388 | EFI_RTC_MINOR); | |
389 | return ret; | |
390 | } | |
391 | ||
392 | dir = create_proc_read_entry ("driver/efirtc", 0, NULL, | |
393 | efi_rtc_read_proc, NULL); | |
394 | if (dir == NULL) { | |
395 | printk(KERN_ERR "efirtc: can't create /proc/driver/efirtc.\n"); | |
396 | misc_deregister(&efi_rtc_dev); | |
397 | return -1; | |
398 | } | |
399 | return 0; | |
400 | } | |
401 | ||
402 | static void __exit | |
403 | efi_rtc_exit(void) | |
404 | { | |
405 | /* not yet used */ | |
406 | } | |
407 | ||
408 | module_init(efi_rtc_init); | |
409 | module_exit(efi_rtc_exit); | |
410 | ||
411 | MODULE_LICENSE("GPL"); |