Commit | Line | Data |
---|---|---|
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 | ||
14 | #include <linux/module.h> | |
15 | #include <linux/rtc.h> | |
16 | ||
17 | static struct class *rtc_dev_class; | |
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 | { | |
24 | int err; | |
25 | struct rtc_device *rtc = container_of(inode->i_cdev, | |
26 | struct rtc_device, char_dev); | |
ff8371ac | 27 | const struct rtc_class_ops *ops = rtc->ops; |
e824290e AZ |
28 | |
29 | /* We keep the lock as long as the device is in use | |
30 | * and return immediately if busy | |
31 | */ | |
32 | if (!(mutex_trylock(&rtc->char_lock))) | |
33 | return -EBUSY; | |
34 | ||
35 | file->private_data = &rtc->class_dev; | |
36 | ||
37 | err = ops->open ? ops->open(rtc->class_dev.dev) : 0; | |
38 | if (err == 0) { | |
39 | spin_lock_irq(&rtc->irq_lock); | |
40 | rtc->irq_data = 0; | |
41 | spin_unlock_irq(&rtc->irq_lock); | |
42 | ||
43 | return 0; | |
44 | } | |
45 | ||
46 | /* something has gone wrong, release the lock */ | |
47 | mutex_unlock(&rtc->char_lock); | |
48 | return err; | |
49 | } | |
50 | ||
655066c3 AN |
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 | */ | |
c4028958 | 56 | static void rtc_uie_task(struct work_struct *work) |
655066c3 | 57 | { |
c4028958 DH |
58 | struct rtc_device *rtc = |
59 | container_of(work, struct rtc_device, uie_task); | |
655066c3 AN |
60 | struct rtc_time tm; |
61 | int num = 0; | |
62 | int err; | |
63 | ||
64 | err = rtc_read_time(&rtc->class_dev, &tm); | |
d728b1e6 DB |
65 | |
66 | local_irq_disable(); | |
67 | spin_lock(&rtc->irq_lock); | |
655066c3 AN |
68 | if (rtc->stop_uie_polling || err) { |
69 | rtc->uie_task_active = 0; | |
70 | } else if (rtc->oldsecs != tm.tm_sec) { | |
71 | num = (tm.tm_sec + 60 - rtc->oldsecs) % 60; | |
72 | rtc->oldsecs = tm.tm_sec; | |
73 | rtc->uie_timer.expires = jiffies + HZ - (HZ/10); | |
74 | rtc->uie_timer_active = 1; | |
75 | rtc->uie_task_active = 0; | |
76 | add_timer(&rtc->uie_timer); | |
77 | } else if (schedule_work(&rtc->uie_task) == 0) { | |
78 | rtc->uie_task_active = 0; | |
79 | } | |
d728b1e6 | 80 | spin_unlock(&rtc->irq_lock); |
655066c3 AN |
81 | if (num) |
82 | rtc_update_irq(&rtc->class_dev, num, RTC_UF | RTC_IRQF); | |
d728b1e6 | 83 | local_irq_enable(); |
655066c3 | 84 | } |
655066c3 AN |
85 | static void rtc_uie_timer(unsigned long data) |
86 | { | |
87 | struct rtc_device *rtc = (struct rtc_device *)data; | |
88 | unsigned long flags; | |
89 | ||
90 | spin_lock_irqsave(&rtc->irq_lock, flags); | |
91 | rtc->uie_timer_active = 0; | |
92 | rtc->uie_task_active = 1; | |
93 | if ((schedule_work(&rtc->uie_task) == 0)) | |
94 | rtc->uie_task_active = 0; | |
95 | spin_unlock_irqrestore(&rtc->irq_lock, flags); | |
96 | } | |
97 | ||
98 | static void clear_uie(struct rtc_device *rtc) | |
99 | { | |
100 | spin_lock_irq(&rtc->irq_lock); | |
101 | if (rtc->irq_active) { | |
102 | rtc->stop_uie_polling = 1; | |
103 | if (rtc->uie_timer_active) { | |
104 | spin_unlock_irq(&rtc->irq_lock); | |
105 | del_timer_sync(&rtc->uie_timer); | |
106 | spin_lock_irq(&rtc->irq_lock); | |
107 | rtc->uie_timer_active = 0; | |
108 | } | |
109 | if (rtc->uie_task_active) { | |
110 | spin_unlock_irq(&rtc->irq_lock); | |
111 | flush_scheduled_work(); | |
112 | spin_lock_irq(&rtc->irq_lock); | |
113 | } | |
114 | rtc->irq_active = 0; | |
115 | } | |
116 | spin_unlock_irq(&rtc->irq_lock); | |
117 | } | |
118 | ||
119 | static int set_uie(struct rtc_device *rtc) | |
120 | { | |
121 | struct rtc_time tm; | |
122 | int err; | |
123 | ||
124 | err = rtc_read_time(&rtc->class_dev, &tm); | |
125 | if (err) | |
126 | return err; | |
127 | spin_lock_irq(&rtc->irq_lock); | |
128 | if (!rtc->irq_active) { | |
129 | rtc->irq_active = 1; | |
130 | rtc->stop_uie_polling = 0; | |
131 | rtc->oldsecs = tm.tm_sec; | |
132 | rtc->uie_task_active = 1; | |
133 | if (schedule_work(&rtc->uie_task) == 0) | |
134 | rtc->uie_task_active = 0; | |
135 | } | |
136 | rtc->irq_data = 0; | |
137 | spin_unlock_irq(&rtc->irq_lock); | |
138 | return 0; | |
139 | } | |
140 | #endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */ | |
e824290e AZ |
141 | |
142 | static ssize_t | |
143 | rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
144 | { | |
145 | struct rtc_device *rtc = to_rtc_device(file->private_data); | |
146 | ||
147 | DECLARE_WAITQUEUE(wait, current); | |
148 | unsigned long data; | |
149 | ssize_t ret; | |
150 | ||
3418ff76 | 151 | if (count != sizeof(unsigned int) && count < sizeof(unsigned long)) |
e824290e AZ |
152 | return -EINVAL; |
153 | ||
154 | add_wait_queue(&rtc->irq_queue, &wait); | |
155 | do { | |
156 | __set_current_state(TASK_INTERRUPTIBLE); | |
157 | ||
158 | spin_lock_irq(&rtc->irq_lock); | |
159 | data = rtc->irq_data; | |
160 | rtc->irq_data = 0; | |
161 | spin_unlock_irq(&rtc->irq_lock); | |
162 | ||
163 | if (data != 0) { | |
164 | ret = 0; | |
165 | break; | |
166 | } | |
167 | if (file->f_flags & O_NONBLOCK) { | |
168 | ret = -EAGAIN; | |
169 | break; | |
170 | } | |
171 | if (signal_pending(current)) { | |
172 | ret = -ERESTARTSYS; | |
173 | break; | |
174 | } | |
175 | schedule(); | |
176 | } while (1); | |
177 | set_current_state(TASK_RUNNING); | |
178 | remove_wait_queue(&rtc->irq_queue, &wait); | |
179 | ||
180 | if (ret == 0) { | |
181 | /* Check for any data updates */ | |
182 | if (rtc->ops->read_callback) | |
3418ff76 AN |
183 | data = rtc->ops->read_callback(rtc->class_dev.dev, |
184 | data); | |
185 | ||
186 | if (sizeof(int) != sizeof(long) && | |
187 | count == sizeof(unsigned int)) | |
188 | ret = put_user(data, (unsigned int __user *)buf) ?: | |
189 | sizeof(unsigned int); | |
190 | else | |
191 | ret = put_user(data, (unsigned long __user *)buf) ?: | |
192 | sizeof(unsigned long); | |
e824290e AZ |
193 | } |
194 | return ret; | |
195 | } | |
196 | ||
197 | static unsigned int rtc_dev_poll(struct file *file, poll_table *wait) | |
198 | { | |
199 | struct rtc_device *rtc = to_rtc_device(file->private_data); | |
200 | unsigned long data; | |
201 | ||
202 | poll_wait(file, &rtc->irq_queue, wait); | |
203 | ||
204 | data = rtc->irq_data; | |
205 | ||
206 | return (data != 0) ? (POLLIN | POLLRDNORM) : 0; | |
207 | } | |
208 | ||
209 | static int rtc_dev_ioctl(struct inode *inode, struct file *file, | |
210 | unsigned int cmd, unsigned long arg) | |
211 | { | |
212 | int err = 0; | |
213 | struct class_device *class_dev = file->private_data; | |
214 | struct rtc_device *rtc = to_rtc_device(class_dev); | |
ff8371ac | 215 | const struct rtc_class_ops *ops = rtc->ops; |
e824290e AZ |
216 | struct rtc_time tm; |
217 | struct rtc_wkalrm alarm; | |
218 | void __user *uarg = (void __user *) arg; | |
219 | ||
2601a464 | 220 | /* check that the calling task has appropriate permissions |
110d693d AZ |
221 | * for certain ioctls. doing this check here is useful |
222 | * to avoid duplicate code in each driver. | |
223 | */ | |
224 | switch (cmd) { | |
225 | case RTC_EPOCH_SET: | |
226 | case RTC_SET_TIME: | |
227 | if (!capable(CAP_SYS_TIME)) | |
228 | return -EACCES; | |
229 | break; | |
230 | ||
231 | case RTC_IRQP_SET: | |
232 | if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE)) | |
233 | return -EACCES; | |
234 | break; | |
235 | ||
236 | case RTC_PIE_ON: | |
237 | if (!capable(CAP_SYS_RESOURCE)) | |
238 | return -EACCES; | |
239 | break; | |
240 | } | |
241 | ||
e824290e AZ |
242 | /* avoid conflicting IRQ users */ |
243 | if (cmd == RTC_PIE_ON || cmd == RTC_PIE_OFF || cmd == RTC_IRQP_SET) { | |
d728b1e6 | 244 | spin_lock_irq(&rtc->irq_task_lock); |
e824290e AZ |
245 | if (rtc->irq_task) |
246 | err = -EBUSY; | |
d728b1e6 | 247 | spin_unlock_irq(&rtc->irq_task_lock); |
e824290e AZ |
248 | |
249 | if (err < 0) | |
250 | return err; | |
251 | } | |
252 | ||
253 | /* try the driver's ioctl interface */ | |
254 | if (ops->ioctl) { | |
255 | err = ops->ioctl(class_dev->dev, cmd, arg); | |
b3969e58 | 256 | if (err != -ENOIOCTLCMD) |
e824290e AZ |
257 | return err; |
258 | } | |
259 | ||
260 | /* if the driver does not provide the ioctl interface | |
261 | * or if that particular ioctl was not implemented | |
b3969e58 | 262 | * (-ENOIOCTLCMD), we will try to emulate here. |
e824290e AZ |
263 | */ |
264 | ||
265 | switch (cmd) { | |
266 | case RTC_ALM_READ: | |
267 | err = rtc_read_alarm(class_dev, &alarm); | |
268 | if (err < 0) | |
269 | return err; | |
270 | ||
271 | if (copy_to_user(uarg, &alarm.time, sizeof(tm))) | |
272 | return -EFAULT; | |
273 | break; | |
274 | ||
275 | case RTC_ALM_SET: | |
276 | if (copy_from_user(&alarm.time, uarg, sizeof(tm))) | |
277 | return -EFAULT; | |
278 | ||
279 | alarm.enabled = 0; | |
280 | alarm.pending = 0; | |
281 | alarm.time.tm_mday = -1; | |
282 | alarm.time.tm_mon = -1; | |
283 | alarm.time.tm_year = -1; | |
284 | alarm.time.tm_wday = -1; | |
285 | alarm.time.tm_yday = -1; | |
286 | alarm.time.tm_isdst = -1; | |
287 | err = rtc_set_alarm(class_dev, &alarm); | |
288 | break; | |
289 | ||
290 | case RTC_RD_TIME: | |
291 | err = rtc_read_time(class_dev, &tm); | |
292 | if (err < 0) | |
293 | return err; | |
294 | ||
295 | if (copy_to_user(uarg, &tm, sizeof(tm))) | |
296 | return -EFAULT; | |
297 | break; | |
298 | ||
299 | case RTC_SET_TIME: | |
e824290e AZ |
300 | if (copy_from_user(&tm, uarg, sizeof(tm))) |
301 | return -EFAULT; | |
302 | ||
303 | err = rtc_set_time(class_dev, &tm); | |
304 | break; | |
2601a464 DB |
305 | |
306 | case RTC_IRQP_READ: | |
307 | if (ops->irq_set_freq) | |
d76fdf75 | 308 | err = put_user(rtc->irq_freq, (unsigned long __user *)uarg); |
2601a464 DB |
309 | break; |
310 | ||
311 | case RTC_IRQP_SET: | |
312 | if (ops->irq_set_freq) | |
313 | err = rtc_irq_set_freq(class_dev, rtc->irq_task, arg); | |
314 | break; | |
315 | ||
e824290e AZ |
316 | #if 0 |
317 | case RTC_EPOCH_SET: | |
318 | #ifndef rtc_epoch | |
319 | /* | |
320 | * There were no RTC clocks before 1900. | |
321 | */ | |
322 | if (arg < 1900) { | |
323 | err = -EINVAL; | |
324 | break; | |
325 | } | |
e824290e AZ |
326 | rtc_epoch = arg; |
327 | err = 0; | |
328 | #endif | |
329 | break; | |
330 | ||
331 | case RTC_EPOCH_READ: | |
332 | err = put_user(rtc_epoch, (unsigned long __user *)uarg); | |
333 | break; | |
334 | #endif | |
335 | case RTC_WKALM_SET: | |
336 | if (copy_from_user(&alarm, uarg, sizeof(alarm))) | |
337 | return -EFAULT; | |
338 | ||
339 | err = rtc_set_alarm(class_dev, &alarm); | |
340 | break; | |
341 | ||
342 | case RTC_WKALM_RD: | |
343 | err = rtc_read_alarm(class_dev, &alarm); | |
344 | if (err < 0) | |
345 | return err; | |
346 | ||
347 | if (copy_to_user(uarg, &alarm, sizeof(alarm))) | |
348 | return -EFAULT; | |
349 | break; | |
350 | ||
655066c3 AN |
351 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
352 | case RTC_UIE_OFF: | |
353 | clear_uie(rtc); | |
354 | return 0; | |
355 | ||
356 | case RTC_UIE_ON: | |
357 | return set_uie(rtc); | |
358 | #endif | |
e824290e | 359 | default: |
b3969e58 | 360 | err = -ENOTTY; |
e824290e AZ |
361 | break; |
362 | } | |
363 | ||
364 | return err; | |
365 | } | |
366 | ||
367 | static int rtc_dev_release(struct inode *inode, struct file *file) | |
368 | { | |
369 | struct rtc_device *rtc = to_rtc_device(file->private_data); | |
370 | ||
655066c3 AN |
371 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
372 | clear_uie(rtc); | |
373 | #endif | |
e824290e AZ |
374 | if (rtc->ops->release) |
375 | rtc->ops->release(rtc->class_dev.dev); | |
376 | ||
377 | mutex_unlock(&rtc->char_lock); | |
378 | return 0; | |
379 | } | |
380 | ||
381 | static int rtc_dev_fasync(int fd, struct file *file, int on) | |
382 | { | |
383 | struct rtc_device *rtc = to_rtc_device(file->private_data); | |
384 | return fasync_helper(fd, file, on, &rtc->async_queue); | |
385 | } | |
386 | ||
d54b1fdb | 387 | static const struct file_operations rtc_dev_fops = { |
e824290e AZ |
388 | .owner = THIS_MODULE, |
389 | .llseek = no_llseek, | |
390 | .read = rtc_dev_read, | |
391 | .poll = rtc_dev_poll, | |
392 | .ioctl = rtc_dev_ioctl, | |
393 | .open = rtc_dev_open, | |
394 | .release = rtc_dev_release, | |
395 | .fasync = rtc_dev_fasync, | |
396 | }; | |
397 | ||
398 | /* insertion/removal hooks */ | |
399 | ||
400 | static int rtc_dev_add_device(struct class_device *class_dev, | |
401 | struct class_interface *class_intf) | |
402 | { | |
403 | int err = 0; | |
404 | struct rtc_device *rtc = to_rtc_device(class_dev); | |
405 | ||
406 | if (rtc->id >= RTC_DEV_MAX) { | |
407 | dev_err(class_dev->dev, "too many RTCs\n"); | |
408 | return -EINVAL; | |
409 | } | |
410 | ||
411 | mutex_init(&rtc->char_lock); | |
412 | spin_lock_init(&rtc->irq_lock); | |
413 | init_waitqueue_head(&rtc->irq_queue); | |
655066c3 | 414 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
c4028958 | 415 | INIT_WORK(&rtc->uie_task, rtc_uie_task); |
655066c3 AN |
416 | setup_timer(&rtc->uie_timer, rtc_uie_timer, (unsigned long)rtc); |
417 | #endif | |
e824290e AZ |
418 | |
419 | cdev_init(&rtc->char_dev, &rtc_dev_fops); | |
420 | rtc->char_dev.owner = rtc->owner; | |
421 | ||
422 | if (cdev_add(&rtc->char_dev, MKDEV(MAJOR(rtc_devt), rtc->id), 1)) { | |
e824290e AZ |
423 | dev_err(class_dev->dev, |
424 | "failed to add char device %d:%d\n", | |
425 | MAJOR(rtc_devt), rtc->id); | |
426 | return -ENODEV; | |
427 | } | |
428 | ||
429 | rtc->rtc_dev = class_device_create(rtc_dev_class, NULL, | |
430 | MKDEV(MAJOR(rtc_devt), rtc->id), | |
431 | class_dev->dev, "rtc%d", rtc->id); | |
432 | if (IS_ERR(rtc->rtc_dev)) { | |
433 | dev_err(class_dev->dev, "cannot create rtc_dev device\n"); | |
434 | err = PTR_ERR(rtc->rtc_dev); | |
435 | goto err_cdev_del; | |
436 | } | |
437 | ||
5a6534e4 | 438 | dev_dbg(class_dev->dev, "rtc intf: dev (%d:%d)\n", |
e824290e AZ |
439 | MAJOR(rtc->rtc_dev->devt), |
440 | MINOR(rtc->rtc_dev->devt)); | |
441 | ||
442 | return 0; | |
443 | ||
444 | err_cdev_del: | |
445 | ||
446 | cdev_del(&rtc->char_dev); | |
447 | return err; | |
448 | } | |
449 | ||
450 | static void rtc_dev_remove_device(struct class_device *class_dev, | |
451 | struct class_interface *class_intf) | |
452 | { | |
453 | struct rtc_device *rtc = to_rtc_device(class_dev); | |
454 | ||
455 | if (rtc->rtc_dev) { | |
456 | dev_dbg(class_dev->dev, "removing char %d:%d\n", | |
457 | MAJOR(rtc->rtc_dev->devt), | |
458 | MINOR(rtc->rtc_dev->devt)); | |
459 | ||
460 | class_device_unregister(rtc->rtc_dev); | |
461 | cdev_del(&rtc->char_dev); | |
462 | } | |
463 | } | |
464 | ||
465 | /* interface registration */ | |
466 | ||
467 | static struct class_interface rtc_dev_interface = { | |
468 | .add = &rtc_dev_add_device, | |
469 | .remove = &rtc_dev_remove_device, | |
470 | }; | |
471 | ||
472 | static int __init rtc_dev_init(void) | |
473 | { | |
474 | int err; | |
475 | ||
476 | rtc_dev_class = class_create(THIS_MODULE, "rtc-dev"); | |
477 | if (IS_ERR(rtc_dev_class)) | |
478 | return PTR_ERR(rtc_dev_class); | |
479 | ||
480 | err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc"); | |
481 | if (err < 0) { | |
482 | printk(KERN_ERR "%s: failed to allocate char dev region\n", | |
483 | __FILE__); | |
484 | goto err_destroy_class; | |
485 | } | |
486 | ||
487 | err = rtc_interface_register(&rtc_dev_interface); | |
488 | if (err < 0) { | |
489 | printk(KERN_ERR "%s: failed to register the interface\n", | |
490 | __FILE__); | |
491 | goto err_unregister_chrdev; | |
492 | } | |
493 | ||
494 | return 0; | |
495 | ||
496 | err_unregister_chrdev: | |
497 | unregister_chrdev_region(rtc_devt, RTC_DEV_MAX); | |
498 | ||
499 | err_destroy_class: | |
500 | class_destroy(rtc_dev_class); | |
501 | ||
502 | return err; | |
503 | } | |
504 | ||
505 | static void __exit rtc_dev_exit(void) | |
506 | { | |
507 | class_interface_unregister(&rtc_dev_interface); | |
508 | class_destroy(rtc_dev_class); | |
509 | unregister_chrdev_region(rtc_devt, RTC_DEV_MAX); | |
510 | } | |
511 | ||
818a8674 | 512 | subsys_initcall(rtc_dev_init); |
e824290e AZ |
513 | module_exit(rtc_dev_exit); |
514 | ||
515 | MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); | |
516 | MODULE_DESCRIPTION("RTC class dev interface"); | |
517 | MODULE_LICENSE("GPL"); |