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1 | /* | |
2 | * SPDX-License-Identifier: GPL-2.0-or-later | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * rtc.c - Use /dev/rtc for clock access | |
10 | */ | |
11 | #include <asm/ioctl.h> | |
12 | #include <errno.h> | |
13 | #include <linux/rtc.h> | |
14 | #include <linux/types.h> | |
15 | #include <fcntl.h> | |
16 | #include <stdio.h> | |
17 | #include <stdlib.h> | |
18 | #include <sys/ioctl.h> | |
19 | #include <sys/select.h> | |
20 | #include <sys/time.h> | |
21 | #include <time.h> | |
22 | #include <unistd.h> | |
23 | ||
24 | #include "monotonic.h" | |
25 | #include "strutils.h" | |
26 | #include "xalloc.h" | |
27 | #include "nls.h" | |
28 | ||
29 | #include "hwclock.h" | |
30 | ||
31 | #ifndef RTC_PARAM_GET | |
32 | struct rtc_param { | |
33 | __u64 param; | |
34 | union { | |
35 | __u64 uvalue; | |
36 | __s64 svalue; | |
37 | __u64 ptr; | |
38 | }; | |
39 | __u32 index; | |
40 | __u32 __pad; | |
41 | }; | |
42 | ||
43 | # define RTC_PARAM_GET _IOW('p', 0x13, struct rtc_param) | |
44 | # define RTC_PARAM_SET _IOW('p', 0x14, struct rtc_param) | |
45 | ||
46 | # define RTC_PARAM_FEATURES 0 | |
47 | # define RTC_PARAM_CORRECTION 1 | |
48 | # define RTC_PARAM_BACKUP_SWITCH_MODE 2 | |
49 | #endif /* RTC_PARAM_GET */ | |
50 | ||
51 | static const struct hwclock_param hwclock_params[] = | |
52 | { | |
53 | { RTC_PARAM_FEATURES, "features", N_("supported features") }, | |
54 | { RTC_PARAM_CORRECTION, "correction", N_("time correction") }, | |
55 | { RTC_PARAM_BACKUP_SWITCH_MODE, "bsm", N_("backup switch mode") }, | |
56 | { } | |
57 | }; | |
58 | ||
59 | const struct hwclock_param *get_hwclock_params(void) | |
60 | { | |
61 | return hwclock_params; | |
62 | } | |
63 | ||
64 | /* | |
65 | * /dev/rtc is conventionally chardev 10/135 | |
66 | * ia64 uses /dev/efirtc, chardev 10/136 | |
67 | * devfs (obsolete) used /dev/misc/... for miscdev | |
68 | * new RTC framework + udev uses dynamic major and /dev/rtc0.../dev/rtcN | |
69 | * ... so we need an overridable default | |
70 | */ | |
71 | ||
72 | /* default or user defined dev (by hwclock --rtc=<path>) */ | |
73 | static const char *rtc_dev_name; | |
74 | static int rtc_dev_fd = -1; | |
75 | ||
76 | static void close_rtc(void) | |
77 | { | |
78 | if (rtc_dev_fd != -1) | |
79 | close(rtc_dev_fd); | |
80 | rtc_dev_fd = -1; | |
81 | } | |
82 | ||
83 | static int open_rtc(const struct hwclock_control *ctl) | |
84 | { | |
85 | static const char * const fls[] = { | |
86 | #ifdef __ia64__ | |
87 | "/dev/efirtc", | |
88 | "/dev/misc/efirtc", | |
89 | #endif | |
90 | "/dev/rtc0", | |
91 | "/dev/rtc", | |
92 | "/dev/misc/rtc" | |
93 | }; | |
94 | size_t i; | |
95 | ||
96 | if (rtc_dev_fd != -1) | |
97 | return rtc_dev_fd; | |
98 | ||
99 | /* --rtc option has been given */ | |
100 | if (ctl->rtc_dev_name) { | |
101 | rtc_dev_name = ctl->rtc_dev_name; | |
102 | rtc_dev_fd = open(rtc_dev_name, O_RDONLY); | |
103 | } else { | |
104 | for (i = 0; i < ARRAY_SIZE(fls); i++) { | |
105 | if (ctl->verbose) | |
106 | printf(_("Trying to open: %s\n"), fls[i]); | |
107 | rtc_dev_fd = open(fls[i], O_RDONLY); | |
108 | ||
109 | if (rtc_dev_fd < 0) { | |
110 | if (errno == ENOENT || errno == ENODEV) | |
111 | continue; | |
112 | if (ctl->verbose) | |
113 | warn(_("cannot open %s"), fls[i]); | |
114 | } | |
115 | rtc_dev_name = fls[i]; | |
116 | break; | |
117 | } | |
118 | if (rtc_dev_fd < 0) | |
119 | rtc_dev_name = *fls; /* default for error messages */ | |
120 | } | |
121 | if (rtc_dev_fd != -1) | |
122 | atexit(close_rtc); | |
123 | return rtc_dev_fd; | |
124 | } | |
125 | ||
126 | static int open_rtc_or_exit(const struct hwclock_control *ctl) | |
127 | { | |
128 | int rtc_fd = open_rtc(ctl); | |
129 | ||
130 | if (rtc_fd < 0) { | |
131 | warn(_("cannot open rtc device")); | |
132 | hwclock_exit(ctl, EXIT_FAILURE); | |
133 | } | |
134 | return rtc_fd; | |
135 | } | |
136 | ||
137 | static int do_rtc_read_ioctl(int rtc_fd, struct tm *tm) | |
138 | { | |
139 | int rc = -1; | |
140 | struct rtc_time rtc_tm = { 0 }; | |
141 | ||
142 | rc = ioctl(rtc_fd, RTC_RD_TIME, &rtc_tm); | |
143 | ||
144 | if (rc == -1) { | |
145 | warn(_("ioctl(RTC_RD_NAME) to %s to read the time failed"), | |
146 | rtc_dev_name); | |
147 | return -1; | |
148 | } | |
149 | ||
150 | /* kernel uses private struct tm definition to be self contained */ | |
151 | tm->tm_sec = rtc_tm.tm_sec; | |
152 | tm->tm_min = rtc_tm.tm_min; | |
153 | tm->tm_hour = rtc_tm.tm_hour; | |
154 | tm->tm_mday = rtc_tm.tm_mday; | |
155 | tm->tm_mon = rtc_tm.tm_mon; | |
156 | tm->tm_year = rtc_tm.tm_year; | |
157 | tm->tm_wday = rtc_tm.tm_wday; | |
158 | tm->tm_yday = rtc_tm.tm_yday; | |
159 | tm->tm_isdst = -1; /* don't know whether it's dst */ | |
160 | return 0; | |
161 | } | |
162 | ||
163 | /* | |
164 | * Wait for the top of a clock tick by reading /dev/rtc in a busy loop | |
165 | * until we see it. This function is used for rtc drivers without ioctl | |
166 | * interrupts. This is typical on an Alpha, where the Hardware Clock | |
167 | * interrupts are used by the kernel for the system clock, so aren't at | |
168 | * the user's disposal. | |
169 | */ | |
170 | static int busywait_for_rtc_clock_tick(const struct hwclock_control *ctl, | |
171 | const int rtc_fd) | |
172 | { | |
173 | struct tm start_time = { 0 }; | |
174 | /* The time when we were called (and started waiting) */ | |
175 | struct tm nowtime = { 0 }; | |
176 | int rc; | |
177 | struct timeval begin = { 0 }, now = { 0 }; | |
178 | ||
179 | if (ctl->verbose) { | |
180 | printf("ioctl(%d, RTC_UIE_ON, 0): %s\n", | |
181 | rtc_fd, strerror(errno)); | |
182 | printf(_("Waiting in loop for time from %s to change\n"), | |
183 | rtc_dev_name); | |
184 | } | |
185 | ||
186 | if (do_rtc_read_ioctl(rtc_fd, &start_time)) | |
187 | return 1; | |
188 | ||
189 | /* | |
190 | * Wait for change. Should be within a second, but in case | |
191 | * something weird happens, we have a time limit (1.5s) on this loop | |
192 | * to reduce the impact of this failure. | |
193 | */ | |
194 | gettime_monotonic(&begin); | |
195 | do { | |
196 | rc = do_rtc_read_ioctl(rtc_fd, &nowtime); | |
197 | if (rc || start_time.tm_sec != nowtime.tm_sec) | |
198 | break; | |
199 | gettime_monotonic(&now); | |
200 | if (time_diff(now, begin) > 1.5) { | |
201 | warnx(_("Timed out waiting for time change.")); | |
202 | return 1; | |
203 | } | |
204 | } while (1); | |
205 | ||
206 | if (rc) | |
207 | return 1; | |
208 | return 0; | |
209 | } | |
210 | ||
211 | /* | |
212 | * Same as synchronize_to_clock_tick(), but just for /dev/rtc. | |
213 | */ | |
214 | static int synchronize_to_clock_tick_rtc(const struct hwclock_control *ctl) | |
215 | { | |
216 | int rtc_fd; /* File descriptor of /dev/rtc */ | |
217 | int ret = 1; | |
218 | ||
219 | rtc_fd = open_rtc(ctl); | |
220 | if (rtc_fd == -1) { | |
221 | warn(_("cannot open rtc device")); | |
222 | return ret; | |
223 | } | |
224 | ||
225 | /* Turn on update interrupts (one per second) */ | |
226 | int rc = ioctl(rtc_fd, RTC_UIE_ON, 0); | |
227 | ||
228 | if (rc != -1) { | |
229 | /* | |
230 | * Just reading rtc_fd fails on broken hardware: no | |
231 | * update interrupt comes and a bootscript with a | |
232 | * hwclock call hangs | |
233 | */ | |
234 | fd_set rfds; | |
235 | struct timeval tv; | |
236 | ||
237 | /* | |
238 | * Wait up to ten seconds for the next update | |
239 | * interrupt | |
240 | */ | |
241 | FD_ZERO(&rfds); | |
242 | FD_SET(rtc_fd, &rfds); | |
243 | tv.tv_sec = 10; | |
244 | tv.tv_usec = 0; | |
245 | rc = select(rtc_fd + 1, &rfds, NULL, NULL, &tv); | |
246 | if (0 < rc) | |
247 | ret = 0; | |
248 | else if (rc == 0) { | |
249 | warnx(_("select() to %s to wait for clock tick timed out"), | |
250 | rtc_dev_name); | |
251 | } else | |
252 | warn(_("select() to %s to wait for clock tick failed"), | |
253 | rtc_dev_name); | |
254 | /* Turn off update interrupts */ | |
255 | rc = ioctl(rtc_fd, RTC_UIE_OFF, 0); | |
256 | if (rc == -1) | |
257 | warn(_("ioctl() to %s to turn off update interrupts failed"), | |
258 | rtc_dev_name); | |
259 | } else if (errno == ENOTTY || errno == EINVAL) { | |
260 | /* rtc ioctl interrupts are unimplemented */ | |
261 | ret = busywait_for_rtc_clock_tick(ctl, rtc_fd); | |
262 | } else | |
263 | warn(_("ioctl(%d, RTC_UIE_ON, 0) to %s failed"), | |
264 | rtc_fd, rtc_dev_name); | |
265 | return ret; | |
266 | } | |
267 | ||
268 | static int read_hardware_clock_rtc(const struct hwclock_control *ctl, | |
269 | struct tm *tm) | |
270 | { | |
271 | int rtc_fd, rc; | |
272 | ||
273 | rtc_fd = open_rtc_or_exit(ctl); | |
274 | ||
275 | /* Read the RTC time/date, return answer via tm */ | |
276 | rc = do_rtc_read_ioctl(rtc_fd, tm); | |
277 | ||
278 | return rc; | |
279 | } | |
280 | ||
281 | /* | |
282 | * Set the Hardware Clock to the broken down time <new_broken_time>. Use | |
283 | * ioctls to "rtc" device /dev/rtc. | |
284 | */ | |
285 | static int set_hardware_clock_rtc(const struct hwclock_control *ctl, | |
286 | const struct tm *new_broken_time) | |
287 | { | |
288 | int rc = -1; | |
289 | int rtc_fd; | |
290 | struct rtc_time rtc_tm = { 0 }; | |
291 | ||
292 | rtc_fd = open_rtc_or_exit(ctl); | |
293 | ||
294 | /* kernel uses private struct tm definition to be self contained */ | |
295 | rtc_tm.tm_sec = new_broken_time->tm_sec; | |
296 | rtc_tm.tm_min = new_broken_time->tm_min; | |
297 | rtc_tm.tm_hour = new_broken_time->tm_hour; | |
298 | rtc_tm.tm_mday = new_broken_time->tm_mday; | |
299 | rtc_tm.tm_mon = new_broken_time->tm_mon; | |
300 | rtc_tm.tm_year = new_broken_time->tm_year; | |
301 | rtc_tm.tm_wday = new_broken_time->tm_wday; | |
302 | rtc_tm.tm_yday = new_broken_time->tm_yday; | |
303 | rtc_tm.tm_isdst = new_broken_time->tm_isdst; | |
304 | ||
305 | rc = ioctl(rtc_fd, RTC_SET_TIME, &rtc_tm); | |
306 | ||
307 | if (rc == -1) { | |
308 | warn(_("ioctl(RTC_SET_TIME) to %s to set the time failed"), | |
309 | rtc_dev_name); | |
310 | hwclock_exit(ctl, EXIT_FAILURE); | |
311 | } | |
312 | ||
313 | if (ctl->verbose) | |
314 | printf(_("ioctl(RTC_SET_TIME) was successful.\n")); | |
315 | ||
316 | return 0; | |
317 | } | |
318 | ||
319 | static int get_permissions_rtc(void) | |
320 | { | |
321 | return 0; | |
322 | } | |
323 | ||
324 | static const char *get_device_path(void) | |
325 | { | |
326 | return rtc_dev_name; | |
327 | } | |
328 | ||
329 | static const struct clock_ops rtc_interface = { | |
330 | N_("Using the rtc interface to the clock."), | |
331 | get_permissions_rtc, | |
332 | read_hardware_clock_rtc, | |
333 | set_hardware_clock_rtc, | |
334 | synchronize_to_clock_tick_rtc, | |
335 | get_device_path, | |
336 | }; | |
337 | ||
338 | /* return &rtc if /dev/rtc can be opened, NULL otherwise */ | |
339 | const struct clock_ops *probe_for_rtc_clock(const struct hwclock_control *ctl) | |
340 | { | |
341 | const int rtc_fd = open_rtc(ctl); | |
342 | ||
343 | if (rtc_fd < 0) | |
344 | return NULL; | |
345 | return &rtc_interface; | |
346 | } | |
347 | ||
348 | #ifdef __alpha__ | |
349 | /* | |
350 | * Get the Hardware Clock epoch setting from the kernel. | |
351 | */ | |
352 | int get_epoch_rtc(const struct hwclock_control *ctl, unsigned long *epoch_p) | |
353 | { | |
354 | int rtc_fd; | |
355 | ||
356 | rtc_fd = open_rtc(ctl); | |
357 | if (rtc_fd < 0) { | |
358 | warn(_("cannot open %s"), rtc_dev_name); | |
359 | return 1; | |
360 | } | |
361 | ||
362 | if (ioctl(rtc_fd, RTC_EPOCH_READ, epoch_p) == -1) { | |
363 | warn(_("ioctl(%d, RTC_EPOCH_READ, epoch_p) to %s failed"), | |
364 | rtc_fd, rtc_dev_name); | |
365 | return 1; | |
366 | } | |
367 | ||
368 | if (ctl->verbose) | |
369 | printf(_("ioctl(%d, RTC_EPOCH_READ, epoch_p) to %s succeeded.\n"), | |
370 | rtc_fd, rtc_dev_name); | |
371 | ||
372 | return 0; | |
373 | } | |
374 | ||
375 | /* | |
376 | * Set the Hardware Clock epoch in the kernel. | |
377 | */ | |
378 | int set_epoch_rtc(const struct hwclock_control *ctl) | |
379 | { | |
380 | int rtc_fd; | |
381 | unsigned long epoch; | |
382 | ||
383 | errno = 0; | |
384 | epoch = strtoul(ctl->epoch_option, NULL, 10); | |
385 | ||
386 | /* There were no RTC clocks before 1900. */ | |
387 | if (errno || epoch < 1900 || epoch == ULONG_MAX) { | |
388 | warnx(_("invalid epoch '%s'."), ctl->epoch_option); | |
389 | return 1; | |
390 | } | |
391 | ||
392 | rtc_fd = open_rtc(ctl); | |
393 | if (rtc_fd < 0) { | |
394 | warn(_("cannot open %s"), rtc_dev_name); | |
395 | return 1; | |
396 | } | |
397 | ||
398 | if (ioctl(rtc_fd, RTC_EPOCH_SET, epoch) == -1) { | |
399 | warn(_("ioctl(%d, RTC_EPOCH_SET, %lu) to %s failed"), | |
400 | rtc_fd, epoch, rtc_dev_name); | |
401 | return 1; | |
402 | } | |
403 | ||
404 | if (ctl->verbose) | |
405 | printf(_("ioctl(%d, RTC_EPOCH_SET, %lu) to %s succeeded.\n"), | |
406 | rtc_fd, epoch, rtc_dev_name); | |
407 | ||
408 | return 0; | |
409 | } | |
410 | #endif /* __alpha__ */ | |
411 | ||
412 | ||
413 | ||
414 | static int resolve_rtc_param_alias(const char *alias, __u64 *value) | |
415 | { | |
416 | const struct hwclock_param *param = &hwclock_params[0]; | |
417 | ||
418 | while (param->name) { | |
419 | if (!strcmp(alias, param->name)) { | |
420 | *value = param->id; | |
421 | return 0; | |
422 | } | |
423 | param++; | |
424 | } | |
425 | ||
426 | return 1; | |
427 | } | |
428 | ||
429 | /* kernel uapi __u64 can be defined differently than uint64_t */ | |
430 | static int strtoku64(const char *str, __u64 *num, int base) | |
431 | { | |
432 | return ul_strtou64(str, (uint64_t *) &num, base); | |
433 | } | |
434 | ||
435 | /* | |
436 | * Get the Hardware Clock parameter setting from the kernel. | |
437 | */ | |
438 | int get_param_rtc(const struct hwclock_control *ctl, | |
439 | const char *name, uint64_t *id, uint64_t *value) | |
440 | { | |
441 | int rtc_fd; | |
442 | struct rtc_param param = { .param = 0 }; | |
443 | ||
444 | /* handle name */ | |
445 | if (resolve_rtc_param_alias(name, ¶m.param) != 0 | |
446 | && strtoku64(name, ¶m.param, 0) != 0) { | |
447 | warnx(_("could not convert parameter name to number")); | |
448 | return 1; | |
449 | } | |
450 | ||
451 | /* get parameter */ | |
452 | rtc_fd = open_rtc(ctl); | |
453 | if (rtc_fd < 0) { | |
454 | warn(_("cannot open %s"), rtc_dev_name); | |
455 | return 1; | |
456 | } | |
457 | ||
458 | if (ioctl(rtc_fd, RTC_PARAM_GET, ¶m) == -1) { | |
459 | warn(_("ioctl(%d, RTC_PARAM_GET, param) to %s failed"), | |
460 | rtc_fd, rtc_dev_name); | |
461 | return 1; | |
462 | } | |
463 | ||
464 | if (id) | |
465 | *id = param.param; | |
466 | if (value) | |
467 | *value = param.uvalue; | |
468 | ||
469 | if (ctl->verbose) | |
470 | printf(_("ioctl(%d, RTC_PARAM_GET, param) to %s succeeded.\n"), | |
471 | rtc_fd, rtc_dev_name); | |
472 | ||
473 | return 0; | |
474 | } | |
475 | ||
476 | /* | |
477 | * Set the Hardware Clock parameter in the kernel. | |
478 | */ | |
479 | int set_param_rtc(const struct hwclock_control *ctl, const char *opt0) | |
480 | { | |
481 | int rtc_fd, rc = 1; | |
482 | struct rtc_param param = { .param = 0 }; | |
483 | char *tok, *opt = xstrdup(opt0); | |
484 | ||
485 | /* handle name */ | |
486 | tok = strtok(opt, "="); | |
487 | if (resolve_rtc_param_alias(tok, ¶m.param) != 0 | |
488 | && strtoku64(tok, ¶m.param, 0) != 0) { | |
489 | warnx(_("could not convert parameter name to number")); | |
490 | goto done; | |
491 | } | |
492 | ||
493 | /* handle value */ | |
494 | tok = strtok(NULL, "="); | |
495 | if (!tok) { | |
496 | warnx(_("expected <param>=<value>")); | |
497 | goto done; | |
498 | } | |
499 | if (strtoku64(tok, ¶m.uvalue, 0) != 0) { | |
500 | warnx(_("could not convert parameter value to number")); | |
501 | goto done; | |
502 | } | |
503 | ||
504 | /* set parameter */ | |
505 | rtc_fd = open_rtc(ctl); | |
506 | if (rtc_fd < 0) { | |
507 | warnx(_("cannot open %s"), rtc_dev_name); | |
508 | return 1; | |
509 | } | |
510 | ||
511 | if (ioctl(rtc_fd, RTC_PARAM_SET, ¶m) == -1) { | |
512 | warn(_("ioctl(%d, RTC_PARAM_SET, param) to %s failed"), | |
513 | rtc_fd, rtc_dev_name); | |
514 | goto done; | |
515 | } | |
516 | ||
517 | if (ctl->verbose) | |
518 | printf(_("ioctl(%d, RTC_PARAM_SET, param) to %s succeeded.\n"), | |
519 | rtc_fd, rtc_dev_name); | |
520 | ||
521 | rc = 0; | |
522 | done: | |
523 | free(opt); | |
524 | return rc; | |
525 | } | |
526 | ||
527 | #ifndef RTC_VL_DATA_INVALID | |
528 | #define RTC_VL_DATA_INVALID 0x1 | |
529 | #endif | |
530 | #ifndef RTC_VL_BACKUP_LOW | |
531 | #define RTC_VL_BACKUP_LOW 0x2 | |
532 | #endif | |
533 | #ifndef RTC_VL_BACKUP_EMPTY | |
534 | #define RTC_VL_BACKUP_EMPTY 0x4 | |
535 | #endif | |
536 | #ifndef RTC_VL_ACCURACY_LOW | |
537 | #define RTC_VL_ACCURACY_LOW 0x8 | |
538 | #endif | |
539 | #ifndef RTC_VL_BACKUP_SWITCH | |
540 | #define RTC_VL_BACKUP_SWITCH 0x10 | |
541 | #endif | |
542 | ||
543 | int rtc_vl_read(const struct hwclock_control *ctl) | |
544 | { | |
545 | unsigned int vl; | |
546 | int rtc_fd; | |
547 | size_t i; | |
548 | static const struct vl_bit { | |
549 | unsigned int bit; | |
550 | const char *desc; | |
551 | } vl_bits[] = { | |
552 | { RTC_VL_DATA_INVALID, N_("Voltage too low, RTC data is invalid") }, | |
553 | { RTC_VL_BACKUP_LOW, N_("Backup voltage is low") }, | |
554 | { RTC_VL_BACKUP_EMPTY, N_("Backup empty or not present") }, | |
555 | { RTC_VL_ACCURACY_LOW, N_("Voltage is low, RTC accuracy is reduced") }, | |
556 | { RTC_VL_BACKUP_SWITCH, N_("Backup switchover happened") }, | |
557 | }; | |
558 | ||
559 | rtc_fd = open_rtc(ctl); | |
560 | if (rtc_fd < 0) { | |
561 | warnx(_("cannot open %s"), rtc_dev_name); | |
562 | return 1; | |
563 | } | |
564 | ||
565 | if (ioctl(rtc_fd, RTC_VL_READ, &vl) == -1) { | |
566 | warn(_("ioctl(%d, RTC_VL_READ) on %s failed"), | |
567 | rtc_fd, rtc_dev_name); | |
568 | return 1; | |
569 | } | |
570 | ||
571 | if (ctl->verbose) { | |
572 | printf(_("ioctl(%d, RTC_VL_READ) on %s returned 0x%x\n"), | |
573 | rtc_fd, rtc_dev_name, vl); | |
574 | } | |
575 | ||
576 | for (i = 0; i < ARRAY_SIZE(vl_bits); ++i) { | |
577 | const struct vl_bit *vlb = &vl_bits[i]; | |
578 | ||
579 | if (vl & vlb->bit) { | |
580 | printf("0x%02x - %s\n", vlb->bit, vlb->desc); | |
581 | vl &= ~vlb->bit; | |
582 | } | |
583 | } | |
584 | if (vl) | |
585 | printf("0x%02x - unknown bit(s)\n", vl); | |
586 | ||
587 | return 0; | |
588 | } | |
589 | ||
590 | int rtc_vl_clear(const struct hwclock_control *ctl) | |
591 | { | |
592 | int rtc_fd; | |
593 | ||
594 | rtc_fd = open_rtc(ctl); | |
595 | if (rtc_fd < 0) { | |
596 | warnx(_("cannot open %s"), rtc_dev_name); | |
597 | return 1; | |
598 | } | |
599 | ||
600 | if (ioctl(rtc_fd, RTC_VL_CLR) == -1) { | |
601 | warn(_("ioctl(%d, RTC_VL_CLEAR) on %s failed"), | |
602 | rtc_fd, rtc_dev_name); | |
603 | return 1; | |
604 | } | |
605 | ||
606 | if (ctl->verbose) | |
607 | printf(_("ioctl(%d, RTC_VL_CLEAR) on %s succeeded.\n"), | |
608 | rtc_fd, rtc_dev_name); | |
609 | ||
610 | return 0; | |
611 | } |