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Commit | Line | Data |
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e824290e AZ |
1 | /* |
2 | * RTC subsystem, dev interface | |
3 | * | |
4 | * Copyright (C) 2005 Tower Technologies | |
5 | * Author: Alessandro Zummo <a.zummo@towertech.it> | |
6 | * | |
7 | * based on arch/arm/common/rtctime.c | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License version 2 as | |
11 | * published by the Free Software Foundation. | |
12 | */ | |
13 | ||
c100a5e0 JH |
14 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
15 | ||
e824290e AZ |
16 | #include <linux/module.h> |
17 | #include <linux/rtc.h> | |
174cd4b1 | 18 | #include <linux/sched/signal.h> |
5726fb20 | 19 | #include "rtc-core.h" |
e824290e | 20 | |
e824290e AZ |
21 | static dev_t rtc_devt; |
22 | ||
23 | #define RTC_DEV_MAX 16 /* 16 RTCs should be enough for everyone... */ | |
24 | ||
25 | static int rtc_dev_open(struct inode *inode, struct file *file) | |
26 | { | |
27 | int err; | |
28 | struct rtc_device *rtc = container_of(inode->i_cdev, | |
29 | struct rtc_device, char_dev); | |
ff8371ac | 30 | const struct rtc_class_ops *ops = rtc->ops; |
e824290e | 31 | |
b1c3c898 DB |
32 | if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags)) |
33 | return -EBUSY; | |
e824290e | 34 | |
ab6a2d70 | 35 | file->private_data = rtc; |
e824290e | 36 | |
cd966209 | 37 | err = ops->open ? ops->open(rtc->dev.parent) : 0; |
e824290e AZ |
38 | if (err == 0) { |
39 | spin_lock_irq(&rtc->irq_lock); | |
40 | rtc->irq_data = 0; | |
41 | spin_unlock_irq(&rtc->irq_lock); | |
42 | ||
b1c3c898 | 43 | return 0; |
e824290e AZ |
44 | } |
45 | ||
8853c202 | 46 | /* something has gone wrong */ |
372a302e | 47 | clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags); |
e824290e AZ |
48 | return err; |
49 | } | |
50 | ||
6e57b1d6 JS |
51 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
52 | /* | |
53 | * Routine to poll RTC seconds field for change as often as possible, | |
54 | * after first RTC_UIE use timer to reduce polling | |
55 | */ | |
56 | static void rtc_uie_task(struct work_struct *work) | |
57 | { | |
58 | struct rtc_device *rtc = | |
59 | container_of(work, struct rtc_device, uie_task); | |
60 | struct rtc_time tm; | |
61 | int num = 0; | |
62 | int err; | |
63 | ||
64 | err = rtc_read_time(rtc, &tm); | |
65 | ||
66 | spin_lock_irq(&rtc->irq_lock); | |
67 | if (rtc->stop_uie_polling || err) { | |
68 | rtc->uie_task_active = 0; | |
69 | } else if (rtc->oldsecs != tm.tm_sec) { | |
70 | num = (tm.tm_sec + 60 - rtc->oldsecs) % 60; | |
71 | rtc->oldsecs = tm.tm_sec; | |
72 | rtc->uie_timer.expires = jiffies + HZ - (HZ/10); | |
73 | rtc->uie_timer_active = 1; | |
74 | rtc->uie_task_active = 0; | |
75 | add_timer(&rtc->uie_timer); | |
76 | } else if (schedule_work(&rtc->uie_task) == 0) { | |
77 | rtc->uie_task_active = 0; | |
78 | } | |
79 | spin_unlock_irq(&rtc->irq_lock); | |
80 | if (num) | |
456d66ec | 81 | rtc_handle_legacy_irq(rtc, num, RTC_UF); |
6e57b1d6 JS |
82 | } |
83 | static void rtc_uie_timer(unsigned long data) | |
84 | { | |
85 | struct rtc_device *rtc = (struct rtc_device *)data; | |
86 | unsigned long flags; | |
87 | ||
88 | spin_lock_irqsave(&rtc->irq_lock, flags); | |
89 | rtc->uie_timer_active = 0; | |
90 | rtc->uie_task_active = 1; | |
91 | if ((schedule_work(&rtc->uie_task) == 0)) | |
92 | rtc->uie_task_active = 0; | |
93 | spin_unlock_irqrestore(&rtc->irq_lock, flags); | |
94 | } | |
95 | ||
96 | static int clear_uie(struct rtc_device *rtc) | |
97 | { | |
98 | spin_lock_irq(&rtc->irq_lock); | |
99 | if (rtc->uie_irq_active) { | |
100 | rtc->stop_uie_polling = 1; | |
101 | if (rtc->uie_timer_active) { | |
102 | spin_unlock_irq(&rtc->irq_lock); | |
103 | del_timer_sync(&rtc->uie_timer); | |
104 | spin_lock_irq(&rtc->irq_lock); | |
105 | rtc->uie_timer_active = 0; | |
106 | } | |
107 | if (rtc->uie_task_active) { | |
108 | spin_unlock_irq(&rtc->irq_lock); | |
109 | flush_scheduled_work(); | |
110 | spin_lock_irq(&rtc->irq_lock); | |
111 | } | |
112 | rtc->uie_irq_active = 0; | |
113 | } | |
114 | spin_unlock_irq(&rtc->irq_lock); | |
115 | return 0; | |
116 | } | |
117 | ||
118 | static int set_uie(struct rtc_device *rtc) | |
119 | { | |
120 | struct rtc_time tm; | |
121 | int err; | |
122 | ||
123 | err = rtc_read_time(rtc, &tm); | |
124 | if (err) | |
125 | return err; | |
126 | spin_lock_irq(&rtc->irq_lock); | |
127 | if (!rtc->uie_irq_active) { | |
128 | rtc->uie_irq_active = 1; | |
129 | rtc->stop_uie_polling = 0; | |
130 | rtc->oldsecs = tm.tm_sec; | |
131 | rtc->uie_task_active = 1; | |
132 | if (schedule_work(&rtc->uie_task) == 0) | |
133 | rtc->uie_task_active = 0; | |
134 | } | |
135 | rtc->irq_data = 0; | |
136 | spin_unlock_irq(&rtc->irq_lock); | |
137 | return 0; | |
138 | } | |
139 | ||
140 | int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc, unsigned int enabled) | |
141 | { | |
142 | if (enabled) | |
143 | return set_uie(rtc); | |
144 | else | |
145 | return clear_uie(rtc); | |
146 | } | |
147 | EXPORT_SYMBOL(rtc_dev_update_irq_enable_emul); | |
148 | ||
149 | #endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */ | |
e824290e AZ |
150 | |
151 | static ssize_t | |
152 | rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
153 | { | |
88efe137 | 154 | struct rtc_device *rtc = file->private_data; |
e824290e AZ |
155 | |
156 | DECLARE_WAITQUEUE(wait, current); | |
157 | unsigned long data; | |
158 | ssize_t ret; | |
159 | ||
3418ff76 | 160 | if (count != sizeof(unsigned int) && count < sizeof(unsigned long)) |
e824290e AZ |
161 | return -EINVAL; |
162 | ||
163 | add_wait_queue(&rtc->irq_queue, &wait); | |
164 | do { | |
165 | __set_current_state(TASK_INTERRUPTIBLE); | |
166 | ||
167 | spin_lock_irq(&rtc->irq_lock); | |
168 | data = rtc->irq_data; | |
169 | rtc->irq_data = 0; | |
170 | spin_unlock_irq(&rtc->irq_lock); | |
171 | ||
172 | if (data != 0) { | |
173 | ret = 0; | |
174 | break; | |
175 | } | |
176 | if (file->f_flags & O_NONBLOCK) { | |
177 | ret = -EAGAIN; | |
178 | break; | |
179 | } | |
180 | if (signal_pending(current)) { | |
181 | ret = -ERESTARTSYS; | |
182 | break; | |
183 | } | |
184 | schedule(); | |
185 | } while (1); | |
186 | set_current_state(TASK_RUNNING); | |
187 | remove_wait_queue(&rtc->irq_queue, &wait); | |
188 | ||
189 | if (ret == 0) { | |
190 | /* Check for any data updates */ | |
191 | if (rtc->ops->read_callback) | |
cd966209 | 192 | data = rtc->ops->read_callback(rtc->dev.parent, |
3418ff76 AN |
193 | data); |
194 | ||
195 | if (sizeof(int) != sizeof(long) && | |
196 | count == sizeof(unsigned int)) | |
197 | ret = put_user(data, (unsigned int __user *)buf) ?: | |
198 | sizeof(unsigned int); | |
199 | else | |
200 | ret = put_user(data, (unsigned long __user *)buf) ?: | |
201 | sizeof(unsigned long); | |
e824290e AZ |
202 | } |
203 | return ret; | |
204 | } | |
205 | ||
206 | static unsigned int rtc_dev_poll(struct file *file, poll_table *wait) | |
207 | { | |
88efe137 | 208 | struct rtc_device *rtc = file->private_data; |
e824290e AZ |
209 | unsigned long data; |
210 | ||
211 | poll_wait(file, &rtc->irq_queue, wait); | |
212 | ||
213 | data = rtc->irq_data; | |
214 | ||
215 | return (data != 0) ? (POLLIN | POLLRDNORM) : 0; | |
216 | } | |
217 | ||
5ad31a57 | 218 | static long rtc_dev_ioctl(struct file *file, |
e824290e AZ |
219 | unsigned int cmd, unsigned long arg) |
220 | { | |
221 | int err = 0; | |
ab6a2d70 | 222 | struct rtc_device *rtc = file->private_data; |
ff8371ac | 223 | const struct rtc_class_ops *ops = rtc->ops; |
e824290e AZ |
224 | struct rtc_time tm; |
225 | struct rtc_wkalrm alarm; | |
226 | void __user *uarg = (void __user *) arg; | |
227 | ||
5ad31a57 DB |
228 | err = mutex_lock_interruptible(&rtc->ops_lock); |
229 | if (err) | |
b68bb263 | 230 | return err; |
5ad31a57 | 231 | |
2601a464 | 232 | /* check that the calling task has appropriate permissions |
110d693d AZ |
233 | * for certain ioctls. doing this check here is useful |
234 | * to avoid duplicate code in each driver. | |
235 | */ | |
236 | switch (cmd) { | |
237 | case RTC_EPOCH_SET: | |
238 | case RTC_SET_TIME: | |
239 | if (!capable(CAP_SYS_TIME)) | |
5ad31a57 | 240 | err = -EACCES; |
110d693d AZ |
241 | break; |
242 | ||
243 | case RTC_IRQP_SET: | |
244 | if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE)) | |
5ad31a57 | 245 | err = -EACCES; |
110d693d AZ |
246 | break; |
247 | ||
248 | case RTC_PIE_ON: | |
9d013d3b BK |
249 | if (rtc->irq_freq > rtc->max_user_freq && |
250 | !capable(CAP_SYS_RESOURCE)) | |
5ad31a57 | 251 | err = -EACCES; |
110d693d AZ |
252 | break; |
253 | } | |
254 | ||
5ad31a57 DB |
255 | if (err) |
256 | goto done; | |
257 | ||
ac54cd2b | 258 | /* |
8a0bdfd7 DB |
259 | * Drivers *SHOULD NOT* provide ioctl implementations |
260 | * for these requests. Instead, provide methods to | |
261 | * support the following code, so that the RTC's main | |
262 | * features are accessible without using ioctls. | |
263 | * | |
264 | * RTC and alarm times will be in UTC, by preference, | |
265 | * but dual-booting with MS-Windows implies RTCs must | |
266 | * use the local wall clock time. | |
e824290e AZ |
267 | */ |
268 | ||
269 | switch (cmd) { | |
270 | case RTC_ALM_READ: | |
5ad31a57 DB |
271 | mutex_unlock(&rtc->ops_lock); |
272 | ||
ab6a2d70 | 273 | err = rtc_read_alarm(rtc, &alarm); |
e824290e AZ |
274 | if (err < 0) |
275 | return err; | |
276 | ||
277 | if (copy_to_user(uarg, &alarm.time, sizeof(tm))) | |
5ad31a57 DB |
278 | err = -EFAULT; |
279 | return err; | |
e824290e AZ |
280 | |
281 | case RTC_ALM_SET: | |
5ad31a57 DB |
282 | mutex_unlock(&rtc->ops_lock); |
283 | ||
e824290e AZ |
284 | if (copy_from_user(&alarm.time, uarg, sizeof(tm))) |
285 | return -EFAULT; | |
286 | ||
287 | alarm.enabled = 0; | |
288 | alarm.pending = 0; | |
e824290e AZ |
289 | alarm.time.tm_wday = -1; |
290 | alarm.time.tm_yday = -1; | |
291 | alarm.time.tm_isdst = -1; | |
f8245c26 DB |
292 | |
293 | /* RTC_ALM_SET alarms may be up to 24 hours in the future. | |
294 | * Rather than expecting every RTC to implement "don't care" | |
295 | * for day/month/year fields, just force the alarm to have | |
296 | * the right values for those fields. | |
297 | * | |
298 | * RTC_WKALM_SET should be used instead. Not only does it | |
299 | * eliminate the need for a separate RTC_AIE_ON call, it | |
300 | * doesn't have the "alarm 23:59:59 in the future" race. | |
301 | * | |
302 | * NOTE: some legacy code may have used invalid fields as | |
303 | * wildcards, exposing hardware "periodic alarm" capabilities. | |
304 | * Not supported here. | |
305 | */ | |
306 | { | |
4ec2364f | 307 | time64_t now, then; |
f8245c26 DB |
308 | |
309 | err = rtc_read_time(rtc, &tm); | |
310 | if (err < 0) | |
311 | return err; | |
4ec2364f | 312 | now = rtc_tm_to_time64(&tm); |
f8245c26 DB |
313 | |
314 | alarm.time.tm_mday = tm.tm_mday; | |
315 | alarm.time.tm_mon = tm.tm_mon; | |
316 | alarm.time.tm_year = tm.tm_year; | |
317 | err = rtc_valid_tm(&alarm.time); | |
318 | if (err < 0) | |
319 | return err; | |
4ec2364f | 320 | then = rtc_tm_to_time64(&alarm.time); |
f8245c26 DB |
321 | |
322 | /* alarm may need to wrap into tomorrow */ | |
323 | if (then < now) { | |
4ec2364f | 324 | rtc_time64_to_tm(now + 24 * 60 * 60, &tm); |
f8245c26 DB |
325 | alarm.time.tm_mday = tm.tm_mday; |
326 | alarm.time.tm_mon = tm.tm_mon; | |
327 | alarm.time.tm_year = tm.tm_year; | |
328 | } | |
329 | } | |
330 | ||
5ad31a57 | 331 | return rtc_set_alarm(rtc, &alarm); |
e824290e AZ |
332 | |
333 | case RTC_RD_TIME: | |
5ad31a57 DB |
334 | mutex_unlock(&rtc->ops_lock); |
335 | ||
ab6a2d70 | 336 | err = rtc_read_time(rtc, &tm); |
e824290e AZ |
337 | if (err < 0) |
338 | return err; | |
339 | ||
340 | if (copy_to_user(uarg, &tm, sizeof(tm))) | |
5ad31a57 DB |
341 | err = -EFAULT; |
342 | return err; | |
e824290e AZ |
343 | |
344 | case RTC_SET_TIME: | |
5ad31a57 DB |
345 | mutex_unlock(&rtc->ops_lock); |
346 | ||
e824290e AZ |
347 | if (copy_from_user(&tm, uarg, sizeof(tm))) |
348 | return -EFAULT; | |
349 | ||
5ad31a57 | 350 | return rtc_set_time(rtc, &tm); |
2601a464 | 351 | |
d691eb90 AZ |
352 | case RTC_PIE_ON: |
353 | err = rtc_irq_set_state(rtc, NULL, 1); | |
354 | break; | |
355 | ||
356 | case RTC_PIE_OFF: | |
357 | err = rtc_irq_set_state(rtc, NULL, 0); | |
2601a464 DB |
358 | break; |
359 | ||
099e6576 AZ |
360 | case RTC_AIE_ON: |
361 | mutex_unlock(&rtc->ops_lock); | |
362 | return rtc_alarm_irq_enable(rtc, 1); | |
363 | ||
364 | case RTC_AIE_OFF: | |
365 | mutex_unlock(&rtc->ops_lock); | |
366 | return rtc_alarm_irq_enable(rtc, 0); | |
367 | ||
368 | case RTC_UIE_ON: | |
369 | mutex_unlock(&rtc->ops_lock); | |
370 | return rtc_update_irq_enable(rtc, 1); | |
371 | ||
372 | case RTC_UIE_OFF: | |
373 | mutex_unlock(&rtc->ops_lock); | |
374 | return rtc_update_irq_enable(rtc, 0); | |
375 | ||
2601a464 | 376 | case RTC_IRQP_SET: |
d691eb90 AZ |
377 | err = rtc_irq_set_freq(rtc, NULL, arg); |
378 | break; | |
379 | ||
380 | case RTC_IRQP_READ: | |
381 | err = put_user(rtc->irq_freq, (unsigned long __user *)uarg); | |
2601a464 DB |
382 | break; |
383 | ||
e824290e | 384 | case RTC_WKALM_SET: |
5ad31a57 | 385 | mutex_unlock(&rtc->ops_lock); |
e824290e AZ |
386 | if (copy_from_user(&alarm, uarg, sizeof(alarm))) |
387 | return -EFAULT; | |
388 | ||
5ad31a57 | 389 | return rtc_set_alarm(rtc, &alarm); |
e824290e AZ |
390 | |
391 | case RTC_WKALM_RD: | |
5ad31a57 | 392 | mutex_unlock(&rtc->ops_lock); |
ab6a2d70 | 393 | err = rtc_read_alarm(rtc, &alarm); |
e824290e AZ |
394 | if (err < 0) |
395 | return err; | |
396 | ||
397 | if (copy_to_user(uarg, &alarm, sizeof(alarm))) | |
5ad31a57 DB |
398 | err = -EFAULT; |
399 | return err; | |
e824290e AZ |
400 | |
401 | default: | |
ac54cd2b JS |
402 | /* Finally try the driver's ioctl interface */ |
403 | if (ops->ioctl) { | |
404 | err = ops->ioctl(rtc->dev.parent, cmd, arg); | |
405 | if (err == -ENOIOCTLCMD) | |
406 | err = -ENOTTY; | |
e17fd4ba JS |
407 | } else |
408 | err = -ENOTTY; | |
e824290e AZ |
409 | break; |
410 | } | |
411 | ||
5ad31a57 DB |
412 | done: |
413 | mutex_unlock(&rtc->ops_lock); | |
e824290e AZ |
414 | return err; |
415 | } | |
416 | ||
2e4a75cd MS |
417 | static int rtc_dev_fasync(int fd, struct file *file, int on) |
418 | { | |
419 | struct rtc_device *rtc = file->private_data; | |
420 | return fasync_helper(fd, file, on, &rtc->async_queue); | |
421 | } | |
422 | ||
e824290e AZ |
423 | static int rtc_dev_release(struct inode *inode, struct file *file) |
424 | { | |
88efe137 | 425 | struct rtc_device *rtc = file->private_data; |
e824290e | 426 | |
743e6a50 DB |
427 | /* We shut down the repeating IRQs that userspace enabled, |
428 | * since nothing is listening to them. | |
429 | * - Update (UIE) ... currently only managed through ioctls | |
430 | * - Periodic (PIE) ... also used through rtc_*() interface calls | |
431 | * | |
432 | * Leave the alarm alone; it may be set to trigger a system wakeup | |
433 | * later, or be used by kernel code, and is a one-shot event anyway. | |
434 | */ | |
099e6576 AZ |
435 | |
436 | /* Keep ioctl until all drivers are converted */ | |
743e6a50 | 437 | rtc_dev_ioctl(file, RTC_UIE_OFF, 0); |
099e6576 | 438 | rtc_update_irq_enable(rtc, 0); |
5cdc98b8 TJ |
439 | rtc_irq_set_state(rtc, NULL, 0); |
440 | ||
e824290e | 441 | if (rtc->ops->release) |
cd966209 | 442 | rtc->ops->release(rtc->dev.parent); |
e824290e | 443 | |
372a302e | 444 | clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags); |
e824290e AZ |
445 | return 0; |
446 | } | |
447 | ||
d54b1fdb | 448 | static const struct file_operations rtc_dev_fops = { |
e824290e AZ |
449 | .owner = THIS_MODULE, |
450 | .llseek = no_llseek, | |
451 | .read = rtc_dev_read, | |
452 | .poll = rtc_dev_poll, | |
5ad31a57 | 453 | .unlocked_ioctl = rtc_dev_ioctl, |
e824290e AZ |
454 | .open = rtc_dev_open, |
455 | .release = rtc_dev_release, | |
456 | .fasync = rtc_dev_fasync, | |
457 | }; | |
458 | ||
459 | /* insertion/removal hooks */ | |
460 | ||
cb3a58d2 | 461 | void rtc_dev_prepare(struct rtc_device *rtc) |
e824290e | 462 | { |
5726fb20 DB |
463 | if (!rtc_devt) |
464 | return; | |
e824290e AZ |
465 | |
466 | if (rtc->id >= RTC_DEV_MAX) { | |
c100a5e0 | 467 | dev_dbg(&rtc->dev, "%s: too many RTC devices\n", rtc->name); |
5726fb20 | 468 | return; |
e824290e AZ |
469 | } |
470 | ||
cd966209 | 471 | rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id); |
5726fb20 | 472 | |
6e57b1d6 JS |
473 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
474 | INIT_WORK(&rtc->uie_task, rtc_uie_task); | |
475 | setup_timer(&rtc->uie_timer, rtc_uie_timer, (unsigned long)rtc); | |
476 | #endif | |
477 | ||
e824290e AZ |
478 | cdev_init(&rtc->char_dev, &rtc_dev_fops); |
479 | rtc->char_dev.owner = rtc->owner; | |
e824290e AZ |
480 | } |
481 | ||
5726fb20 | 482 | void __init rtc_dev_init(void) |
e824290e AZ |
483 | { |
484 | int err; | |
485 | ||
e824290e | 486 | err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc"); |
5726fb20 | 487 | if (err < 0) |
c100a5e0 | 488 | pr_err("failed to allocate char dev region\n"); |
e824290e AZ |
489 | } |
490 | ||
5726fb20 | 491 | void __exit rtc_dev_exit(void) |
e824290e | 492 | { |
5726fb20 DB |
493 | if (rtc_devt) |
494 | unregister_chrdev_region(rtc_devt, RTC_DEV_MAX); | |
e824290e | 495 | } |