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 | ||
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); | |
65 | spin_lock_irq(&rtc->irq_lock); | |
66 | if (rtc->stop_uie_polling || err) { | |
67 | rtc->uie_task_active = 0; | |
68 | } else if (rtc->oldsecs != tm.tm_sec) { | |
69 | num = (tm.tm_sec + 60 - rtc->oldsecs) % 60; | |
70 | rtc->oldsecs = tm.tm_sec; | |
71 | rtc->uie_timer.expires = jiffies + HZ - (HZ/10); | |
72 | rtc->uie_timer_active = 1; | |
73 | rtc->uie_task_active = 0; | |
74 | add_timer(&rtc->uie_timer); | |
75 | } else if (schedule_work(&rtc->uie_task) == 0) { | |
76 | rtc->uie_task_active = 0; | |
77 | } | |
78 | spin_unlock_irq(&rtc->irq_lock); | |
79 | if (num) | |
80 | rtc_update_irq(&rtc->class_dev, num, RTC_UF | RTC_IRQF); | |
81 | } | |
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 void clear_uie(struct rtc_device *rtc) | |
97 | { | |
98 | spin_lock_irq(&rtc->irq_lock); | |
99 | if (rtc->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->irq_active = 0; | |
113 | } | |
114 | spin_unlock_irq(&rtc->irq_lock); | |
115 | } | |
116 | ||
117 | static int set_uie(struct rtc_device *rtc) | |
118 | { | |
119 | struct rtc_time tm; | |
120 | int err; | |
121 | ||
122 | err = rtc_read_time(&rtc->class_dev, &tm); | |
123 | if (err) | |
124 | return err; | |
125 | spin_lock_irq(&rtc->irq_lock); | |
126 | if (!rtc->irq_active) { | |
127 | rtc->irq_active = 1; | |
128 | rtc->stop_uie_polling = 0; | |
129 | rtc->oldsecs = tm.tm_sec; | |
130 | rtc->uie_task_active = 1; | |
131 | if (schedule_work(&rtc->uie_task) == 0) | |
132 | rtc->uie_task_active = 0; | |
133 | } | |
134 | rtc->irq_data = 0; | |
135 | spin_unlock_irq(&rtc->irq_lock); | |
136 | return 0; | |
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 | { | |
143 | struct rtc_device *rtc = to_rtc_device(file->private_data); | |
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) { | |
179 | /* Check for any data updates */ | |
180 | if (rtc->ops->read_callback) | |
3418ff76 AN |
181 | data = rtc->ops->read_callback(rtc->class_dev.dev, |
182 | data); | |
183 | ||
184 | if (sizeof(int) != sizeof(long) && | |
185 | count == sizeof(unsigned int)) | |
186 | ret = put_user(data, (unsigned int __user *)buf) ?: | |
187 | sizeof(unsigned int); | |
188 | else | |
189 | ret = put_user(data, (unsigned long __user *)buf) ?: | |
190 | sizeof(unsigned long); | |
e824290e AZ |
191 | } |
192 | return ret; | |
193 | } | |
194 | ||
195 | static unsigned int rtc_dev_poll(struct file *file, poll_table *wait) | |
196 | { | |
197 | struct rtc_device *rtc = to_rtc_device(file->private_data); | |
198 | unsigned long data; | |
199 | ||
200 | poll_wait(file, &rtc->irq_queue, wait); | |
201 | ||
202 | data = rtc->irq_data; | |
203 | ||
204 | return (data != 0) ? (POLLIN | POLLRDNORM) : 0; | |
205 | } | |
206 | ||
207 | static int rtc_dev_ioctl(struct inode *inode, struct file *file, | |
208 | unsigned int cmd, unsigned long arg) | |
209 | { | |
210 | int err = 0; | |
211 | struct class_device *class_dev = file->private_data; | |
212 | struct rtc_device *rtc = to_rtc_device(class_dev); | |
ff8371ac | 213 | const struct rtc_class_ops *ops = rtc->ops; |
e824290e AZ |
214 | struct rtc_time tm; |
215 | struct rtc_wkalrm alarm; | |
216 | void __user *uarg = (void __user *) arg; | |
217 | ||
110d693d AZ |
218 | /* check that the calles has appropriate permissions |
219 | * for certain ioctls. doing this check here is useful | |
220 | * to avoid duplicate code in each driver. | |
221 | */ | |
222 | switch (cmd) { | |
223 | case RTC_EPOCH_SET: | |
224 | case RTC_SET_TIME: | |
225 | if (!capable(CAP_SYS_TIME)) | |
226 | return -EACCES; | |
227 | break; | |
228 | ||
229 | case RTC_IRQP_SET: | |
230 | if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE)) | |
231 | return -EACCES; | |
232 | break; | |
233 | ||
234 | case RTC_PIE_ON: | |
235 | if (!capable(CAP_SYS_RESOURCE)) | |
236 | return -EACCES; | |
237 | break; | |
238 | } | |
239 | ||
e824290e AZ |
240 | /* avoid conflicting IRQ users */ |
241 | if (cmd == RTC_PIE_ON || cmd == RTC_PIE_OFF || cmd == RTC_IRQP_SET) { | |
242 | spin_lock(&rtc->irq_task_lock); | |
243 | if (rtc->irq_task) | |
244 | err = -EBUSY; | |
245 | spin_unlock(&rtc->irq_task_lock); | |
246 | ||
247 | if (err < 0) | |
248 | return err; | |
249 | } | |
250 | ||
251 | /* try the driver's ioctl interface */ | |
252 | if (ops->ioctl) { | |
253 | err = ops->ioctl(class_dev->dev, cmd, arg); | |
b3969e58 | 254 | if (err != -ENOIOCTLCMD) |
e824290e AZ |
255 | return err; |
256 | } | |
257 | ||
258 | /* if the driver does not provide the ioctl interface | |
259 | * or if that particular ioctl was not implemented | |
b3969e58 | 260 | * (-ENOIOCTLCMD), we will try to emulate here. |
e824290e AZ |
261 | */ |
262 | ||
263 | switch (cmd) { | |
264 | case RTC_ALM_READ: | |
265 | err = rtc_read_alarm(class_dev, &alarm); | |
266 | if (err < 0) | |
267 | return err; | |
268 | ||
269 | if (copy_to_user(uarg, &alarm.time, sizeof(tm))) | |
270 | return -EFAULT; | |
271 | break; | |
272 | ||
273 | case RTC_ALM_SET: | |
274 | if (copy_from_user(&alarm.time, uarg, sizeof(tm))) | |
275 | return -EFAULT; | |
276 | ||
277 | alarm.enabled = 0; | |
278 | alarm.pending = 0; | |
279 | alarm.time.tm_mday = -1; | |
280 | alarm.time.tm_mon = -1; | |
281 | alarm.time.tm_year = -1; | |
282 | alarm.time.tm_wday = -1; | |
283 | alarm.time.tm_yday = -1; | |
284 | alarm.time.tm_isdst = -1; | |
285 | err = rtc_set_alarm(class_dev, &alarm); | |
286 | break; | |
287 | ||
288 | case RTC_RD_TIME: | |
289 | err = rtc_read_time(class_dev, &tm); | |
290 | if (err < 0) | |
291 | return err; | |
292 | ||
293 | if (copy_to_user(uarg, &tm, sizeof(tm))) | |
294 | return -EFAULT; | |
295 | break; | |
296 | ||
297 | case RTC_SET_TIME: | |
e824290e AZ |
298 | if (copy_from_user(&tm, uarg, sizeof(tm))) |
299 | return -EFAULT; | |
300 | ||
301 | err = rtc_set_time(class_dev, &tm); | |
302 | break; | |
303 | #if 0 | |
304 | case RTC_EPOCH_SET: | |
305 | #ifndef rtc_epoch | |
306 | /* | |
307 | * There were no RTC clocks before 1900. | |
308 | */ | |
309 | if (arg < 1900) { | |
310 | err = -EINVAL; | |
311 | break; | |
312 | } | |
e824290e AZ |
313 | rtc_epoch = arg; |
314 | err = 0; | |
315 | #endif | |
316 | break; | |
317 | ||
318 | case RTC_EPOCH_READ: | |
319 | err = put_user(rtc_epoch, (unsigned long __user *)uarg); | |
320 | break; | |
321 | #endif | |
322 | case RTC_WKALM_SET: | |
323 | if (copy_from_user(&alarm, uarg, sizeof(alarm))) | |
324 | return -EFAULT; | |
325 | ||
326 | err = rtc_set_alarm(class_dev, &alarm); | |
327 | break; | |
328 | ||
329 | case RTC_WKALM_RD: | |
330 | err = rtc_read_alarm(class_dev, &alarm); | |
331 | if (err < 0) | |
332 | return err; | |
333 | ||
334 | if (copy_to_user(uarg, &alarm, sizeof(alarm))) | |
335 | return -EFAULT; | |
336 | break; | |
337 | ||
655066c3 AN |
338 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
339 | case RTC_UIE_OFF: | |
340 | clear_uie(rtc); | |
341 | return 0; | |
342 | ||
343 | case RTC_UIE_ON: | |
344 | return set_uie(rtc); | |
345 | #endif | |
e824290e | 346 | default: |
b3969e58 | 347 | err = -ENOTTY; |
e824290e AZ |
348 | break; |
349 | } | |
350 | ||
351 | return err; | |
352 | } | |
353 | ||
354 | static int rtc_dev_release(struct inode *inode, struct file *file) | |
355 | { | |
356 | struct rtc_device *rtc = to_rtc_device(file->private_data); | |
357 | ||
655066c3 AN |
358 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
359 | clear_uie(rtc); | |
360 | #endif | |
e824290e AZ |
361 | if (rtc->ops->release) |
362 | rtc->ops->release(rtc->class_dev.dev); | |
363 | ||
364 | mutex_unlock(&rtc->char_lock); | |
365 | return 0; | |
366 | } | |
367 | ||
368 | static int rtc_dev_fasync(int fd, struct file *file, int on) | |
369 | { | |
370 | struct rtc_device *rtc = to_rtc_device(file->private_data); | |
371 | return fasync_helper(fd, file, on, &rtc->async_queue); | |
372 | } | |
373 | ||
374 | static struct file_operations rtc_dev_fops = { | |
375 | .owner = THIS_MODULE, | |
376 | .llseek = no_llseek, | |
377 | .read = rtc_dev_read, | |
378 | .poll = rtc_dev_poll, | |
379 | .ioctl = rtc_dev_ioctl, | |
380 | .open = rtc_dev_open, | |
381 | .release = rtc_dev_release, | |
382 | .fasync = rtc_dev_fasync, | |
383 | }; | |
384 | ||
385 | /* insertion/removal hooks */ | |
386 | ||
387 | static int rtc_dev_add_device(struct class_device *class_dev, | |
388 | struct class_interface *class_intf) | |
389 | { | |
390 | int err = 0; | |
391 | struct rtc_device *rtc = to_rtc_device(class_dev); | |
392 | ||
393 | if (rtc->id >= RTC_DEV_MAX) { | |
394 | dev_err(class_dev->dev, "too many RTCs\n"); | |
395 | return -EINVAL; | |
396 | } | |
397 | ||
398 | mutex_init(&rtc->char_lock); | |
399 | spin_lock_init(&rtc->irq_lock); | |
400 | init_waitqueue_head(&rtc->irq_queue); | |
655066c3 | 401 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
c4028958 | 402 | INIT_WORK(&rtc->uie_task, rtc_uie_task); |
655066c3 AN |
403 | setup_timer(&rtc->uie_timer, rtc_uie_timer, (unsigned long)rtc); |
404 | #endif | |
e824290e AZ |
405 | |
406 | cdev_init(&rtc->char_dev, &rtc_dev_fops); | |
407 | rtc->char_dev.owner = rtc->owner; | |
408 | ||
409 | if (cdev_add(&rtc->char_dev, MKDEV(MAJOR(rtc_devt), rtc->id), 1)) { | |
e824290e AZ |
410 | dev_err(class_dev->dev, |
411 | "failed to add char device %d:%d\n", | |
412 | MAJOR(rtc_devt), rtc->id); | |
413 | return -ENODEV; | |
414 | } | |
415 | ||
416 | rtc->rtc_dev = class_device_create(rtc_dev_class, NULL, | |
417 | MKDEV(MAJOR(rtc_devt), rtc->id), | |
418 | class_dev->dev, "rtc%d", rtc->id); | |
419 | if (IS_ERR(rtc->rtc_dev)) { | |
420 | dev_err(class_dev->dev, "cannot create rtc_dev device\n"); | |
421 | err = PTR_ERR(rtc->rtc_dev); | |
422 | goto err_cdev_del; | |
423 | } | |
424 | ||
425 | dev_info(class_dev->dev, "rtc intf: dev (%d:%d)\n", | |
426 | MAJOR(rtc->rtc_dev->devt), | |
427 | MINOR(rtc->rtc_dev->devt)); | |
428 | ||
429 | return 0; | |
430 | ||
431 | err_cdev_del: | |
432 | ||
433 | cdev_del(&rtc->char_dev); | |
434 | return err; | |
435 | } | |
436 | ||
437 | static void rtc_dev_remove_device(struct class_device *class_dev, | |
438 | struct class_interface *class_intf) | |
439 | { | |
440 | struct rtc_device *rtc = to_rtc_device(class_dev); | |
441 | ||
442 | if (rtc->rtc_dev) { | |
443 | dev_dbg(class_dev->dev, "removing char %d:%d\n", | |
444 | MAJOR(rtc->rtc_dev->devt), | |
445 | MINOR(rtc->rtc_dev->devt)); | |
446 | ||
447 | class_device_unregister(rtc->rtc_dev); | |
448 | cdev_del(&rtc->char_dev); | |
449 | } | |
450 | } | |
451 | ||
452 | /* interface registration */ | |
453 | ||
454 | static struct class_interface rtc_dev_interface = { | |
455 | .add = &rtc_dev_add_device, | |
456 | .remove = &rtc_dev_remove_device, | |
457 | }; | |
458 | ||
459 | static int __init rtc_dev_init(void) | |
460 | { | |
461 | int err; | |
462 | ||
463 | rtc_dev_class = class_create(THIS_MODULE, "rtc-dev"); | |
464 | if (IS_ERR(rtc_dev_class)) | |
465 | return PTR_ERR(rtc_dev_class); | |
466 | ||
467 | err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc"); | |
468 | if (err < 0) { | |
469 | printk(KERN_ERR "%s: failed to allocate char dev region\n", | |
470 | __FILE__); | |
471 | goto err_destroy_class; | |
472 | } | |
473 | ||
474 | err = rtc_interface_register(&rtc_dev_interface); | |
475 | if (err < 0) { | |
476 | printk(KERN_ERR "%s: failed to register the interface\n", | |
477 | __FILE__); | |
478 | goto err_unregister_chrdev; | |
479 | } | |
480 | ||
481 | return 0; | |
482 | ||
483 | err_unregister_chrdev: | |
484 | unregister_chrdev_region(rtc_devt, RTC_DEV_MAX); | |
485 | ||
486 | err_destroy_class: | |
487 | class_destroy(rtc_dev_class); | |
488 | ||
489 | return err; | |
490 | } | |
491 | ||
492 | static void __exit rtc_dev_exit(void) | |
493 | { | |
494 | class_interface_unregister(&rtc_dev_interface); | |
495 | class_destroy(rtc_dev_class); | |
496 | unregister_chrdev_region(rtc_devt, RTC_DEV_MAX); | |
497 | } | |
498 | ||
818a8674 | 499 | subsys_initcall(rtc_dev_init); |
e824290e AZ |
500 | module_exit(rtc_dev_exit); |
501 | ||
502 | MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); | |
503 | MODULE_DESCRIPTION("RTC class dev interface"); | |
504 | MODULE_LICENSE("GPL"); |