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