]>
Commit | Line | Data |
---|---|---|
cdf7545a | 1 | // SPDX-License-Identifier: GPL-2.0 |
e824290e AZ |
2 | /* |
3 | * RTC subsystem, dev interface | |
4 | * | |
5 | * Copyright (C) 2005 Tower Technologies | |
6 | * Author: Alessandro Zummo <a.zummo@towertech.it> | |
7 | * | |
8 | * based on arch/arm/common/rtctime.c | |
cdf7545a | 9 | */ |
e824290e | 10 | |
c100a5e0 JH |
11 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
12 | ||
e824290e AZ |
13 | #include <linux/module.h> |
14 | #include <linux/rtc.h> | |
174cd4b1 | 15 | #include <linux/sched/signal.h> |
5726fb20 | 16 | #include "rtc-core.h" |
e824290e | 17 | |
e824290e AZ |
18 | static dev_t rtc_devt; |
19 | ||
20 | #define RTC_DEV_MAX 16 /* 16 RTCs should be enough for everyone... */ | |
21 | ||
22 | static int rtc_dev_open(struct inode *inode, struct file *file) | |
23 | { | |
e824290e AZ |
24 | struct rtc_device *rtc = container_of(inode->i_cdev, |
25 | struct rtc_device, char_dev); | |
e824290e | 26 | |
b1c3c898 DB |
27 | if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags)) |
28 | return -EBUSY; | |
e824290e | 29 | |
ab6a2d70 | 30 | file->private_data = rtc; |
e824290e | 31 | |
ea369ea6 AB |
32 | spin_lock_irq(&rtc->irq_lock); |
33 | rtc->irq_data = 0; | |
34 | spin_unlock_irq(&rtc->irq_lock); | |
e824290e | 35 | |
ea369ea6 | 36 | return 0; |
e824290e AZ |
37 | } |
38 | ||
6e57b1d6 JS |
39 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
40 | /* | |
41 | * Routine to poll RTC seconds field for change as often as possible, | |
42 | * after first RTC_UIE use timer to reduce polling | |
43 | */ | |
44 | static void rtc_uie_task(struct work_struct *work) | |
45 | { | |
46 | struct rtc_device *rtc = | |
47 | container_of(work, struct rtc_device, uie_task); | |
48 | struct rtc_time tm; | |
49 | int num = 0; | |
50 | int err; | |
51 | ||
52 | err = rtc_read_time(rtc, &tm); | |
53 | ||
54 | spin_lock_irq(&rtc->irq_lock); | |
55 | if (rtc->stop_uie_polling || err) { | |
56 | rtc->uie_task_active = 0; | |
57 | } else if (rtc->oldsecs != tm.tm_sec) { | |
58 | num = (tm.tm_sec + 60 - rtc->oldsecs) % 60; | |
59 | rtc->oldsecs = tm.tm_sec; | |
606cc43c | 60 | rtc->uie_timer.expires = jiffies + HZ - (HZ / 10); |
6e57b1d6 JS |
61 | rtc->uie_timer_active = 1; |
62 | rtc->uie_task_active = 0; | |
63 | add_timer(&rtc->uie_timer); | |
64 | } else if (schedule_work(&rtc->uie_task) == 0) { | |
65 | rtc->uie_task_active = 0; | |
66 | } | |
67 | spin_unlock_irq(&rtc->irq_lock); | |
68 | if (num) | |
456d66ec | 69 | rtc_handle_legacy_irq(rtc, num, RTC_UF); |
6e57b1d6 | 70 | } |
606cc43c | 71 | |
e99e88a9 | 72 | static void rtc_uie_timer(struct timer_list *t) |
6e57b1d6 | 73 | { |
e99e88a9 | 74 | struct rtc_device *rtc = from_timer(rtc, t, uie_timer); |
6e57b1d6 JS |
75 | unsigned long flags; |
76 | ||
77 | spin_lock_irqsave(&rtc->irq_lock, flags); | |
78 | rtc->uie_timer_active = 0; | |
79 | rtc->uie_task_active = 1; | |
80 | if ((schedule_work(&rtc->uie_task) == 0)) | |
81 | rtc->uie_task_active = 0; | |
82 | spin_unlock_irqrestore(&rtc->irq_lock, flags); | |
83 | } | |
84 | ||
85 | static int clear_uie(struct rtc_device *rtc) | |
86 | { | |
87 | spin_lock_irq(&rtc->irq_lock); | |
88 | if (rtc->uie_irq_active) { | |
89 | rtc->stop_uie_polling = 1; | |
90 | if (rtc->uie_timer_active) { | |
91 | spin_unlock_irq(&rtc->irq_lock); | |
92 | del_timer_sync(&rtc->uie_timer); | |
93 | spin_lock_irq(&rtc->irq_lock); | |
94 | rtc->uie_timer_active = 0; | |
95 | } | |
96 | if (rtc->uie_task_active) { | |
97 | spin_unlock_irq(&rtc->irq_lock); | |
98 | flush_scheduled_work(); | |
99 | spin_lock_irq(&rtc->irq_lock); | |
100 | } | |
101 | rtc->uie_irq_active = 0; | |
102 | } | |
103 | spin_unlock_irq(&rtc->irq_lock); | |
104 | return 0; | |
105 | } | |
106 | ||
107 | static int set_uie(struct rtc_device *rtc) | |
108 | { | |
109 | struct rtc_time tm; | |
110 | int err; | |
111 | ||
112 | err = rtc_read_time(rtc, &tm); | |
113 | if (err) | |
114 | return err; | |
115 | spin_lock_irq(&rtc->irq_lock); | |
116 | if (!rtc->uie_irq_active) { | |
117 | rtc->uie_irq_active = 1; | |
118 | rtc->stop_uie_polling = 0; | |
119 | rtc->oldsecs = tm.tm_sec; | |
120 | rtc->uie_task_active = 1; | |
121 | if (schedule_work(&rtc->uie_task) == 0) | |
122 | rtc->uie_task_active = 0; | |
123 | } | |
124 | rtc->irq_data = 0; | |
125 | spin_unlock_irq(&rtc->irq_lock); | |
126 | return 0; | |
127 | } | |
128 | ||
129 | int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc, unsigned int enabled) | |
130 | { | |
131 | if (enabled) | |
132 | return set_uie(rtc); | |
133 | else | |
134 | return clear_uie(rtc); | |
135 | } | |
136 | EXPORT_SYMBOL(rtc_dev_update_irq_enable_emul); | |
137 | ||
138 | #endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */ | |
e824290e AZ |
139 | |
140 | static ssize_t | |
141 | rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
142 | { | |
88efe137 | 143 | struct rtc_device *rtc = file->private_data; |
e824290e AZ |
144 | |
145 | DECLARE_WAITQUEUE(wait, current); | |
146 | unsigned long data; | |
147 | ssize_t ret; | |
148 | ||
3418ff76 | 149 | if (count != sizeof(unsigned int) && count < sizeof(unsigned long)) |
e824290e AZ |
150 | return -EINVAL; |
151 | ||
152 | add_wait_queue(&rtc->irq_queue, &wait); | |
153 | do { | |
154 | __set_current_state(TASK_INTERRUPTIBLE); | |
155 | ||
156 | spin_lock_irq(&rtc->irq_lock); | |
157 | data = rtc->irq_data; | |
158 | rtc->irq_data = 0; | |
159 | spin_unlock_irq(&rtc->irq_lock); | |
160 | ||
161 | if (data != 0) { | |
162 | ret = 0; | |
163 | break; | |
164 | } | |
165 | if (file->f_flags & O_NONBLOCK) { | |
166 | ret = -EAGAIN; | |
167 | break; | |
168 | } | |
169 | if (signal_pending(current)) { | |
170 | ret = -ERESTARTSYS; | |
171 | break; | |
172 | } | |
173 | schedule(); | |
174 | } while (1); | |
175 | set_current_state(TASK_RUNNING); | |
176 | remove_wait_queue(&rtc->irq_queue, &wait); | |
177 | ||
178 | if (ret == 0) { | |
3418ff76 AN |
179 | if (sizeof(int) != sizeof(long) && |
180 | count == sizeof(unsigned int)) | |
181 | ret = put_user(data, (unsigned int __user *)buf) ?: | |
182 | sizeof(unsigned int); | |
183 | else | |
184 | ret = put_user(data, (unsigned long __user *)buf) ?: | |
185 | sizeof(unsigned long); | |
e824290e AZ |
186 | } |
187 | return ret; | |
188 | } | |
189 | ||
afc9a42b | 190 | static __poll_t rtc_dev_poll(struct file *file, poll_table *wait) |
e824290e | 191 | { |
88efe137 | 192 | struct rtc_device *rtc = file->private_data; |
e824290e AZ |
193 | unsigned long data; |
194 | ||
195 | poll_wait(file, &rtc->irq_queue, wait); | |
196 | ||
197 | data = rtc->irq_data; | |
198 | ||
a9a08845 | 199 | return (data != 0) ? (EPOLLIN | EPOLLRDNORM) : 0; |
e824290e AZ |
200 | } |
201 | ||
5ad31a57 | 202 | static long rtc_dev_ioctl(struct file *file, |
606cc43c | 203 | unsigned int cmd, unsigned long arg) |
e824290e AZ |
204 | { |
205 | int err = 0; | |
ab6a2d70 | 206 | struct rtc_device *rtc = file->private_data; |
ff8371ac | 207 | const struct rtc_class_ops *ops = rtc->ops; |
e824290e AZ |
208 | struct rtc_time tm; |
209 | struct rtc_wkalrm alarm; | |
606cc43c | 210 | void __user *uarg = (void __user *)arg; |
e824290e | 211 | |
5ad31a57 DB |
212 | err = mutex_lock_interruptible(&rtc->ops_lock); |
213 | if (err) | |
b68bb263 | 214 | return err; |
5ad31a57 | 215 | |
2601a464 | 216 | /* check that the calling task has appropriate permissions |
110d693d AZ |
217 | * for certain ioctls. doing this check here is useful |
218 | * to avoid duplicate code in each driver. | |
219 | */ | |
220 | switch (cmd) { | |
221 | case RTC_EPOCH_SET: | |
222 | case RTC_SET_TIME: | |
223 | if (!capable(CAP_SYS_TIME)) | |
5ad31a57 | 224 | err = -EACCES; |
110d693d AZ |
225 | break; |
226 | ||
227 | case RTC_IRQP_SET: | |
228 | if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE)) | |
5ad31a57 | 229 | err = -EACCES; |
110d693d AZ |
230 | break; |
231 | ||
232 | case RTC_PIE_ON: | |
9d013d3b | 233 | if (rtc->irq_freq > rtc->max_user_freq && |
606cc43c | 234 | !capable(CAP_SYS_RESOURCE)) |
5ad31a57 | 235 | err = -EACCES; |
110d693d AZ |
236 | break; |
237 | } | |
238 | ||
5ad31a57 DB |
239 | if (err) |
240 | goto done; | |
241 | ||
ac54cd2b | 242 | /* |
8a0bdfd7 DB |
243 | * Drivers *SHOULD NOT* provide ioctl implementations |
244 | * for these requests. Instead, provide methods to | |
245 | * support the following code, so that the RTC's main | |
246 | * features are accessible without using ioctls. | |
247 | * | |
248 | * RTC and alarm times will be in UTC, by preference, | |
249 | * but dual-booting with MS-Windows implies RTCs must | |
250 | * use the local wall clock time. | |
e824290e AZ |
251 | */ |
252 | ||
253 | switch (cmd) { | |
254 | case RTC_ALM_READ: | |
5ad31a57 DB |
255 | mutex_unlock(&rtc->ops_lock); |
256 | ||
ab6a2d70 | 257 | err = rtc_read_alarm(rtc, &alarm); |
e824290e AZ |
258 | if (err < 0) |
259 | return err; | |
260 | ||
261 | if (copy_to_user(uarg, &alarm.time, sizeof(tm))) | |
5ad31a57 DB |
262 | err = -EFAULT; |
263 | return err; | |
e824290e AZ |
264 | |
265 | case RTC_ALM_SET: | |
5ad31a57 DB |
266 | mutex_unlock(&rtc->ops_lock); |
267 | ||
e824290e AZ |
268 | if (copy_from_user(&alarm.time, uarg, sizeof(tm))) |
269 | return -EFAULT; | |
270 | ||
271 | alarm.enabled = 0; | |
272 | alarm.pending = 0; | |
e824290e AZ |
273 | alarm.time.tm_wday = -1; |
274 | alarm.time.tm_yday = -1; | |
275 | alarm.time.tm_isdst = -1; | |
f8245c26 DB |
276 | |
277 | /* RTC_ALM_SET alarms may be up to 24 hours in the future. | |
278 | * Rather than expecting every RTC to implement "don't care" | |
279 | * for day/month/year fields, just force the alarm to have | |
280 | * the right values for those fields. | |
281 | * | |
282 | * RTC_WKALM_SET should be used instead. Not only does it | |
283 | * eliminate the need for a separate RTC_AIE_ON call, it | |
284 | * doesn't have the "alarm 23:59:59 in the future" race. | |
285 | * | |
286 | * NOTE: some legacy code may have used invalid fields as | |
287 | * wildcards, exposing hardware "periodic alarm" capabilities. | |
288 | * Not supported here. | |
289 | */ | |
290 | { | |
4ec2364f | 291 | time64_t now, then; |
f8245c26 DB |
292 | |
293 | err = rtc_read_time(rtc, &tm); | |
294 | if (err < 0) | |
295 | return err; | |
4ec2364f | 296 | now = rtc_tm_to_time64(&tm); |
f8245c26 DB |
297 | |
298 | alarm.time.tm_mday = tm.tm_mday; | |
299 | alarm.time.tm_mon = tm.tm_mon; | |
300 | alarm.time.tm_year = tm.tm_year; | |
301 | err = rtc_valid_tm(&alarm.time); | |
302 | if (err < 0) | |
303 | return err; | |
4ec2364f | 304 | then = rtc_tm_to_time64(&alarm.time); |
f8245c26 DB |
305 | |
306 | /* alarm may need to wrap into tomorrow */ | |
307 | if (then < now) { | |
4ec2364f | 308 | rtc_time64_to_tm(now + 24 * 60 * 60, &tm); |
f8245c26 DB |
309 | alarm.time.tm_mday = tm.tm_mday; |
310 | alarm.time.tm_mon = tm.tm_mon; | |
311 | alarm.time.tm_year = tm.tm_year; | |
312 | } | |
313 | } | |
314 | ||
5ad31a57 | 315 | return rtc_set_alarm(rtc, &alarm); |
e824290e AZ |
316 | |
317 | case RTC_RD_TIME: | |
5ad31a57 DB |
318 | mutex_unlock(&rtc->ops_lock); |
319 | ||
ab6a2d70 | 320 | err = rtc_read_time(rtc, &tm); |
e824290e AZ |
321 | if (err < 0) |
322 | return err; | |
323 | ||
324 | if (copy_to_user(uarg, &tm, sizeof(tm))) | |
5ad31a57 DB |
325 | err = -EFAULT; |
326 | return err; | |
e824290e AZ |
327 | |
328 | case RTC_SET_TIME: | |
5ad31a57 DB |
329 | mutex_unlock(&rtc->ops_lock); |
330 | ||
e824290e AZ |
331 | if (copy_from_user(&tm, uarg, sizeof(tm))) |
332 | return -EFAULT; | |
333 | ||
5ad31a57 | 334 | return rtc_set_time(rtc, &tm); |
2601a464 | 335 | |
d691eb90 | 336 | case RTC_PIE_ON: |
8719d3c9 | 337 | err = rtc_irq_set_state(rtc, 1); |
d691eb90 AZ |
338 | break; |
339 | ||
340 | case RTC_PIE_OFF: | |
8719d3c9 | 341 | err = rtc_irq_set_state(rtc, 0); |
2601a464 DB |
342 | break; |
343 | ||
099e6576 AZ |
344 | case RTC_AIE_ON: |
345 | mutex_unlock(&rtc->ops_lock); | |
346 | return rtc_alarm_irq_enable(rtc, 1); | |
347 | ||
348 | case RTC_AIE_OFF: | |
349 | mutex_unlock(&rtc->ops_lock); | |
350 | return rtc_alarm_irq_enable(rtc, 0); | |
351 | ||
352 | case RTC_UIE_ON: | |
353 | mutex_unlock(&rtc->ops_lock); | |
354 | return rtc_update_irq_enable(rtc, 1); | |
355 | ||
356 | case RTC_UIE_OFF: | |
357 | mutex_unlock(&rtc->ops_lock); | |
358 | return rtc_update_irq_enable(rtc, 0); | |
359 | ||
2601a464 | 360 | case RTC_IRQP_SET: |
8719d3c9 | 361 | err = rtc_irq_set_freq(rtc, arg); |
d691eb90 AZ |
362 | break; |
363 | ||
364 | case RTC_IRQP_READ: | |
365 | err = put_user(rtc->irq_freq, (unsigned long __user *)uarg); | |
2601a464 DB |
366 | break; |
367 | ||
e824290e | 368 | case RTC_WKALM_SET: |
5ad31a57 | 369 | mutex_unlock(&rtc->ops_lock); |
e824290e AZ |
370 | if (copy_from_user(&alarm, uarg, sizeof(alarm))) |
371 | return -EFAULT; | |
372 | ||
5ad31a57 | 373 | return rtc_set_alarm(rtc, &alarm); |
e824290e AZ |
374 | |
375 | case RTC_WKALM_RD: | |
5ad31a57 | 376 | mutex_unlock(&rtc->ops_lock); |
ab6a2d70 | 377 | err = rtc_read_alarm(rtc, &alarm); |
e824290e AZ |
378 | if (err < 0) |
379 | return err; | |
380 | ||
381 | if (copy_to_user(uarg, &alarm, sizeof(alarm))) | |
5ad31a57 DB |
382 | err = -EFAULT; |
383 | return err; | |
e824290e AZ |
384 | |
385 | default: | |
ac54cd2b JS |
386 | /* Finally try the driver's ioctl interface */ |
387 | if (ops->ioctl) { | |
388 | err = ops->ioctl(rtc->dev.parent, cmd, arg); | |
389 | if (err == -ENOIOCTLCMD) | |
390 | err = -ENOTTY; | |
606cc43c | 391 | } else { |
e17fd4ba | 392 | err = -ENOTTY; |
606cc43c | 393 | } |
e824290e AZ |
394 | break; |
395 | } | |
396 | ||
5ad31a57 DB |
397 | done: |
398 | mutex_unlock(&rtc->ops_lock); | |
e824290e AZ |
399 | return err; |
400 | } | |
401 | ||
2e4a75cd MS |
402 | static int rtc_dev_fasync(int fd, struct file *file, int on) |
403 | { | |
404 | struct rtc_device *rtc = file->private_data; | |
606cc43c | 405 | |
2e4a75cd MS |
406 | return fasync_helper(fd, file, on, &rtc->async_queue); |
407 | } | |
408 | ||
e824290e AZ |
409 | static int rtc_dev_release(struct inode *inode, struct file *file) |
410 | { | |
88efe137 | 411 | struct rtc_device *rtc = file->private_data; |
e824290e | 412 | |
743e6a50 DB |
413 | /* We shut down the repeating IRQs that userspace enabled, |
414 | * since nothing is listening to them. | |
415 | * - Update (UIE) ... currently only managed through ioctls | |
416 | * - Periodic (PIE) ... also used through rtc_*() interface calls | |
417 | * | |
418 | * Leave the alarm alone; it may be set to trigger a system wakeup | |
419 | * later, or be used by kernel code, and is a one-shot event anyway. | |
420 | */ | |
099e6576 AZ |
421 | |
422 | /* Keep ioctl until all drivers are converted */ | |
743e6a50 | 423 | rtc_dev_ioctl(file, RTC_UIE_OFF, 0); |
099e6576 | 424 | rtc_update_irq_enable(rtc, 0); |
8719d3c9 | 425 | rtc_irq_set_state(rtc, 0); |
5cdc98b8 | 426 | |
372a302e | 427 | clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags); |
e824290e AZ |
428 | return 0; |
429 | } | |
430 | ||
d54b1fdb | 431 | static const struct file_operations rtc_dev_fops = { |
e824290e AZ |
432 | .owner = THIS_MODULE, |
433 | .llseek = no_llseek, | |
434 | .read = rtc_dev_read, | |
435 | .poll = rtc_dev_poll, | |
5ad31a57 | 436 | .unlocked_ioctl = rtc_dev_ioctl, |
e824290e AZ |
437 | .open = rtc_dev_open, |
438 | .release = rtc_dev_release, | |
439 | .fasync = rtc_dev_fasync, | |
440 | }; | |
441 | ||
442 | /* insertion/removal hooks */ | |
443 | ||
cb3a58d2 | 444 | void rtc_dev_prepare(struct rtc_device *rtc) |
e824290e | 445 | { |
5726fb20 DB |
446 | if (!rtc_devt) |
447 | return; | |
e824290e AZ |
448 | |
449 | if (rtc->id >= RTC_DEV_MAX) { | |
9f860653 | 450 | dev_dbg(&rtc->dev, "too many RTC devices\n"); |
5726fb20 | 451 | return; |
e824290e AZ |
452 | } |
453 | ||
cd966209 | 454 | rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id); |
5726fb20 | 455 | |
6e57b1d6 JS |
456 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
457 | INIT_WORK(&rtc->uie_task, rtc_uie_task); | |
e99e88a9 | 458 | timer_setup(&rtc->uie_timer, rtc_uie_timer, 0); |
6e57b1d6 JS |
459 | #endif |
460 | ||
e824290e AZ |
461 | cdev_init(&rtc->char_dev, &rtc_dev_fops); |
462 | rtc->char_dev.owner = rtc->owner; | |
e824290e AZ |
463 | } |
464 | ||
5726fb20 | 465 | void __init rtc_dev_init(void) |
e824290e AZ |
466 | { |
467 | int err; | |
468 | ||
e824290e | 469 | err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc"); |
5726fb20 | 470 | if (err < 0) |
c100a5e0 | 471 | pr_err("failed to allocate char dev region\n"); |
e824290e AZ |
472 | } |
473 | ||
5726fb20 | 474 | void __exit rtc_dev_exit(void) |
e824290e | 475 | { |
5726fb20 DB |
476 | if (rtc_devt) |
477 | unregister_chrdev_region(rtc_devt, RTC_DEV_MAX); | |
e824290e | 478 | } |