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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> | |
d43c36dc | 16 | #include <linux/sched.h> |
5726fb20 | 17 | #include "rtc-core.h" |
e824290e | 18 | |
e824290e AZ |
19 | static dev_t rtc_devt; |
20 | ||
21 | #define RTC_DEV_MAX 16 /* 16 RTCs should be enough for everyone... */ | |
22 | ||
23 | static int rtc_dev_open(struct inode *inode, struct file *file) | |
24 | { | |
25 | int err; | |
26 | struct rtc_device *rtc = container_of(inode->i_cdev, | |
27 | struct rtc_device, char_dev); | |
ff8371ac | 28 | const struct rtc_class_ops *ops = rtc->ops; |
e824290e | 29 | |
b1c3c898 DB |
30 | if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags)) |
31 | return -EBUSY; | |
e824290e | 32 | |
ab6a2d70 | 33 | file->private_data = rtc; |
e824290e | 34 | |
cd966209 | 35 | err = ops->open ? ops->open(rtc->dev.parent) : 0; |
e824290e AZ |
36 | if (err == 0) { |
37 | spin_lock_irq(&rtc->irq_lock); | |
38 | rtc->irq_data = 0; | |
39 | spin_unlock_irq(&rtc->irq_lock); | |
40 | ||
b1c3c898 | 41 | return 0; |
e824290e AZ |
42 | } |
43 | ||
8853c202 | 44 | /* something has gone wrong */ |
372a302e | 45 | clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags); |
e824290e AZ |
46 | return err; |
47 | } | |
48 | ||
49 | ||
50 | static ssize_t | |
51 | rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
52 | { | |
88efe137 | 53 | struct rtc_device *rtc = file->private_data; |
e824290e AZ |
54 | |
55 | DECLARE_WAITQUEUE(wait, current); | |
56 | unsigned long data; | |
57 | ssize_t ret; | |
58 | ||
3418ff76 | 59 | if (count != sizeof(unsigned int) && count < sizeof(unsigned long)) |
e824290e AZ |
60 | return -EINVAL; |
61 | ||
62 | add_wait_queue(&rtc->irq_queue, &wait); | |
63 | do { | |
64 | __set_current_state(TASK_INTERRUPTIBLE); | |
65 | ||
66 | spin_lock_irq(&rtc->irq_lock); | |
67 | data = rtc->irq_data; | |
68 | rtc->irq_data = 0; | |
69 | spin_unlock_irq(&rtc->irq_lock); | |
70 | ||
71 | if (data != 0) { | |
72 | ret = 0; | |
73 | break; | |
74 | } | |
75 | if (file->f_flags & O_NONBLOCK) { | |
76 | ret = -EAGAIN; | |
77 | break; | |
78 | } | |
79 | if (signal_pending(current)) { | |
80 | ret = -ERESTARTSYS; | |
81 | break; | |
82 | } | |
83 | schedule(); | |
84 | } while (1); | |
85 | set_current_state(TASK_RUNNING); | |
86 | remove_wait_queue(&rtc->irq_queue, &wait); | |
87 | ||
88 | if (ret == 0) { | |
89 | /* Check for any data updates */ | |
90 | if (rtc->ops->read_callback) | |
cd966209 | 91 | data = rtc->ops->read_callback(rtc->dev.parent, |
3418ff76 AN |
92 | data); |
93 | ||
94 | if (sizeof(int) != sizeof(long) && | |
95 | count == sizeof(unsigned int)) | |
96 | ret = put_user(data, (unsigned int __user *)buf) ?: | |
97 | sizeof(unsigned int); | |
98 | else | |
99 | ret = put_user(data, (unsigned long __user *)buf) ?: | |
100 | sizeof(unsigned long); | |
e824290e AZ |
101 | } |
102 | return ret; | |
103 | } | |
104 | ||
105 | static unsigned int rtc_dev_poll(struct file *file, poll_table *wait) | |
106 | { | |
88efe137 | 107 | struct rtc_device *rtc = file->private_data; |
e824290e AZ |
108 | unsigned long data; |
109 | ||
110 | poll_wait(file, &rtc->irq_queue, wait); | |
111 | ||
112 | data = rtc->irq_data; | |
113 | ||
114 | return (data != 0) ? (POLLIN | POLLRDNORM) : 0; | |
115 | } | |
116 | ||
5ad31a57 | 117 | static long rtc_dev_ioctl(struct file *file, |
e824290e AZ |
118 | unsigned int cmd, unsigned long arg) |
119 | { | |
120 | int err = 0; | |
ab6a2d70 | 121 | struct rtc_device *rtc = file->private_data; |
ff8371ac | 122 | const struct rtc_class_ops *ops = rtc->ops; |
e824290e AZ |
123 | struct rtc_time tm; |
124 | struct rtc_wkalrm alarm; | |
125 | void __user *uarg = (void __user *) arg; | |
126 | ||
5ad31a57 DB |
127 | err = mutex_lock_interruptible(&rtc->ops_lock); |
128 | if (err) | |
b68bb263 | 129 | return err; |
5ad31a57 | 130 | |
2601a464 | 131 | /* check that the calling task has appropriate permissions |
110d693d AZ |
132 | * for certain ioctls. doing this check here is useful |
133 | * to avoid duplicate code in each driver. | |
134 | */ | |
135 | switch (cmd) { | |
136 | case RTC_EPOCH_SET: | |
137 | case RTC_SET_TIME: | |
138 | if (!capable(CAP_SYS_TIME)) | |
5ad31a57 | 139 | err = -EACCES; |
110d693d AZ |
140 | break; |
141 | ||
142 | case RTC_IRQP_SET: | |
143 | if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE)) | |
5ad31a57 | 144 | err = -EACCES; |
110d693d AZ |
145 | break; |
146 | ||
147 | case RTC_PIE_ON: | |
9d013d3b BK |
148 | if (rtc->irq_freq > rtc->max_user_freq && |
149 | !capable(CAP_SYS_RESOURCE)) | |
5ad31a57 | 150 | err = -EACCES; |
110d693d AZ |
151 | break; |
152 | } | |
153 | ||
5ad31a57 DB |
154 | if (err) |
155 | goto done; | |
156 | ||
e824290e AZ |
157 | /* try the driver's ioctl interface */ |
158 | if (ops->ioctl) { | |
cd966209 | 159 | err = ops->ioctl(rtc->dev.parent, cmd, arg); |
5ad31a57 DB |
160 | if (err != -ENOIOCTLCMD) { |
161 | mutex_unlock(&rtc->ops_lock); | |
e824290e | 162 | return err; |
5ad31a57 | 163 | } |
e824290e AZ |
164 | } |
165 | ||
166 | /* if the driver does not provide the ioctl interface | |
167 | * or if that particular ioctl was not implemented | |
b3969e58 | 168 | * (-ENOIOCTLCMD), we will try to emulate here. |
8a0bdfd7 DB |
169 | * |
170 | * Drivers *SHOULD NOT* provide ioctl implementations | |
171 | * for these requests. Instead, provide methods to | |
172 | * support the following code, so that the RTC's main | |
173 | * features are accessible without using ioctls. | |
174 | * | |
175 | * RTC and alarm times will be in UTC, by preference, | |
176 | * but dual-booting with MS-Windows implies RTCs must | |
177 | * use the local wall clock time. | |
e824290e AZ |
178 | */ |
179 | ||
180 | switch (cmd) { | |
181 | case RTC_ALM_READ: | |
5ad31a57 DB |
182 | mutex_unlock(&rtc->ops_lock); |
183 | ||
ab6a2d70 | 184 | err = rtc_read_alarm(rtc, &alarm); |
e824290e AZ |
185 | if (err < 0) |
186 | return err; | |
187 | ||
188 | if (copy_to_user(uarg, &alarm.time, sizeof(tm))) | |
5ad31a57 DB |
189 | err = -EFAULT; |
190 | return err; | |
e824290e AZ |
191 | |
192 | case RTC_ALM_SET: | |
5ad31a57 DB |
193 | mutex_unlock(&rtc->ops_lock); |
194 | ||
e824290e AZ |
195 | if (copy_from_user(&alarm.time, uarg, sizeof(tm))) |
196 | return -EFAULT; | |
197 | ||
198 | alarm.enabled = 0; | |
199 | alarm.pending = 0; | |
e824290e AZ |
200 | alarm.time.tm_wday = -1; |
201 | alarm.time.tm_yday = -1; | |
202 | alarm.time.tm_isdst = -1; | |
f8245c26 DB |
203 | |
204 | /* RTC_ALM_SET alarms may be up to 24 hours in the future. | |
205 | * Rather than expecting every RTC to implement "don't care" | |
206 | * for day/month/year fields, just force the alarm to have | |
207 | * the right values for those fields. | |
208 | * | |
209 | * RTC_WKALM_SET should be used instead. Not only does it | |
210 | * eliminate the need for a separate RTC_AIE_ON call, it | |
211 | * doesn't have the "alarm 23:59:59 in the future" race. | |
212 | * | |
213 | * NOTE: some legacy code may have used invalid fields as | |
214 | * wildcards, exposing hardware "periodic alarm" capabilities. | |
215 | * Not supported here. | |
216 | */ | |
217 | { | |
218 | unsigned long now, then; | |
219 | ||
220 | err = rtc_read_time(rtc, &tm); | |
221 | if (err < 0) | |
222 | return err; | |
223 | rtc_tm_to_time(&tm, &now); | |
224 | ||
225 | alarm.time.tm_mday = tm.tm_mday; | |
226 | alarm.time.tm_mon = tm.tm_mon; | |
227 | alarm.time.tm_year = tm.tm_year; | |
228 | err = rtc_valid_tm(&alarm.time); | |
229 | if (err < 0) | |
230 | return err; | |
231 | rtc_tm_to_time(&alarm.time, &then); | |
232 | ||
233 | /* alarm may need to wrap into tomorrow */ | |
234 | if (then < now) { | |
235 | rtc_time_to_tm(now + 24 * 60 * 60, &tm); | |
236 | alarm.time.tm_mday = tm.tm_mday; | |
237 | alarm.time.tm_mon = tm.tm_mon; | |
238 | alarm.time.tm_year = tm.tm_year; | |
239 | } | |
240 | } | |
241 | ||
5ad31a57 | 242 | return rtc_set_alarm(rtc, &alarm); |
e824290e AZ |
243 | |
244 | case RTC_RD_TIME: | |
5ad31a57 DB |
245 | mutex_unlock(&rtc->ops_lock); |
246 | ||
ab6a2d70 | 247 | err = rtc_read_time(rtc, &tm); |
e824290e AZ |
248 | if (err < 0) |
249 | return err; | |
250 | ||
251 | if (copy_to_user(uarg, &tm, sizeof(tm))) | |
5ad31a57 DB |
252 | err = -EFAULT; |
253 | return err; | |
e824290e AZ |
254 | |
255 | case RTC_SET_TIME: | |
5ad31a57 DB |
256 | mutex_unlock(&rtc->ops_lock); |
257 | ||
e824290e AZ |
258 | if (copy_from_user(&tm, uarg, sizeof(tm))) |
259 | return -EFAULT; | |
260 | ||
5ad31a57 | 261 | return rtc_set_time(rtc, &tm); |
2601a464 | 262 | |
d691eb90 AZ |
263 | case RTC_PIE_ON: |
264 | err = rtc_irq_set_state(rtc, NULL, 1); | |
265 | break; | |
266 | ||
267 | case RTC_PIE_OFF: | |
268 | err = rtc_irq_set_state(rtc, NULL, 0); | |
2601a464 DB |
269 | break; |
270 | ||
099e6576 AZ |
271 | case RTC_AIE_ON: |
272 | mutex_unlock(&rtc->ops_lock); | |
273 | return rtc_alarm_irq_enable(rtc, 1); | |
274 | ||
275 | case RTC_AIE_OFF: | |
276 | mutex_unlock(&rtc->ops_lock); | |
277 | return rtc_alarm_irq_enable(rtc, 0); | |
278 | ||
279 | case RTC_UIE_ON: | |
280 | mutex_unlock(&rtc->ops_lock); | |
281 | return rtc_update_irq_enable(rtc, 1); | |
282 | ||
283 | case RTC_UIE_OFF: | |
284 | mutex_unlock(&rtc->ops_lock); | |
285 | return rtc_update_irq_enable(rtc, 0); | |
286 | ||
2601a464 | 287 | case RTC_IRQP_SET: |
d691eb90 AZ |
288 | err = rtc_irq_set_freq(rtc, NULL, arg); |
289 | break; | |
290 | ||
291 | case RTC_IRQP_READ: | |
292 | err = put_user(rtc->irq_freq, (unsigned long __user *)uarg); | |
2601a464 DB |
293 | break; |
294 | ||
e824290e AZ |
295 | #if 0 |
296 | case RTC_EPOCH_SET: | |
297 | #ifndef rtc_epoch | |
298 | /* | |
299 | * There were no RTC clocks before 1900. | |
300 | */ | |
301 | if (arg < 1900) { | |
302 | err = -EINVAL; | |
303 | break; | |
304 | } | |
e824290e AZ |
305 | rtc_epoch = arg; |
306 | err = 0; | |
307 | #endif | |
308 | break; | |
309 | ||
310 | case RTC_EPOCH_READ: | |
311 | err = put_user(rtc_epoch, (unsigned long __user *)uarg); | |
312 | break; | |
313 | #endif | |
314 | case RTC_WKALM_SET: | |
5ad31a57 | 315 | mutex_unlock(&rtc->ops_lock); |
e824290e AZ |
316 | if (copy_from_user(&alarm, uarg, sizeof(alarm))) |
317 | return -EFAULT; | |
318 | ||
5ad31a57 | 319 | return rtc_set_alarm(rtc, &alarm); |
e824290e AZ |
320 | |
321 | case RTC_WKALM_RD: | |
5ad31a57 | 322 | mutex_unlock(&rtc->ops_lock); |
ab6a2d70 | 323 | err = rtc_read_alarm(rtc, &alarm); |
e824290e AZ |
324 | if (err < 0) |
325 | return err; | |
326 | ||
327 | if (copy_to_user(uarg, &alarm, sizeof(alarm))) | |
5ad31a57 DB |
328 | err = -EFAULT; |
329 | return err; | |
e824290e AZ |
330 | |
331 | default: | |
b3969e58 | 332 | err = -ENOTTY; |
e824290e AZ |
333 | break; |
334 | } | |
335 | ||
5ad31a57 DB |
336 | done: |
337 | mutex_unlock(&rtc->ops_lock); | |
e824290e AZ |
338 | return err; |
339 | } | |
340 | ||
2e4a75cd MS |
341 | static int rtc_dev_fasync(int fd, struct file *file, int on) |
342 | { | |
343 | struct rtc_device *rtc = file->private_data; | |
344 | return fasync_helper(fd, file, on, &rtc->async_queue); | |
345 | } | |
346 | ||
e824290e AZ |
347 | static int rtc_dev_release(struct inode *inode, struct file *file) |
348 | { | |
88efe137 | 349 | struct rtc_device *rtc = file->private_data; |
e824290e | 350 | |
743e6a50 DB |
351 | /* We shut down the repeating IRQs that userspace enabled, |
352 | * since nothing is listening to them. | |
353 | * - Update (UIE) ... currently only managed through ioctls | |
354 | * - Periodic (PIE) ... also used through rtc_*() interface calls | |
355 | * | |
356 | * Leave the alarm alone; it may be set to trigger a system wakeup | |
357 | * later, or be used by kernel code, and is a one-shot event anyway. | |
358 | */ | |
099e6576 AZ |
359 | |
360 | /* Keep ioctl until all drivers are converted */ | |
743e6a50 | 361 | rtc_dev_ioctl(file, RTC_UIE_OFF, 0); |
099e6576 | 362 | rtc_update_irq_enable(rtc, 0); |
5cdc98b8 TJ |
363 | rtc_irq_set_state(rtc, NULL, 0); |
364 | ||
e824290e | 365 | if (rtc->ops->release) |
cd966209 | 366 | rtc->ops->release(rtc->dev.parent); |
e824290e | 367 | |
372a302e | 368 | clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags); |
e824290e AZ |
369 | return 0; |
370 | } | |
371 | ||
d54b1fdb | 372 | static const struct file_operations rtc_dev_fops = { |
e824290e AZ |
373 | .owner = THIS_MODULE, |
374 | .llseek = no_llseek, | |
375 | .read = rtc_dev_read, | |
376 | .poll = rtc_dev_poll, | |
5ad31a57 | 377 | .unlocked_ioctl = rtc_dev_ioctl, |
e824290e AZ |
378 | .open = rtc_dev_open, |
379 | .release = rtc_dev_release, | |
380 | .fasync = rtc_dev_fasync, | |
381 | }; | |
382 | ||
383 | /* insertion/removal hooks */ | |
384 | ||
cb3a58d2 | 385 | void rtc_dev_prepare(struct rtc_device *rtc) |
e824290e | 386 | { |
5726fb20 DB |
387 | if (!rtc_devt) |
388 | return; | |
e824290e AZ |
389 | |
390 | if (rtc->id >= RTC_DEV_MAX) { | |
5726fb20 DB |
391 | pr_debug("%s: too many RTC devices\n", rtc->name); |
392 | return; | |
e824290e AZ |
393 | } |
394 | ||
cd966209 | 395 | rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id); |
5726fb20 | 396 | |
e824290e AZ |
397 | cdev_init(&rtc->char_dev, &rtc_dev_fops); |
398 | rtc->char_dev.owner = rtc->owner; | |
cb3a58d2 | 399 | } |
e824290e | 400 | |
cb3a58d2 DB |
401 | void rtc_dev_add_device(struct rtc_device *rtc) |
402 | { | |
cd966209 | 403 | if (cdev_add(&rtc->char_dev, rtc->dev.devt, 1)) |
5726fb20 DB |
404 | printk(KERN_WARNING "%s: failed to add char device %d:%d\n", |
405 | rtc->name, MAJOR(rtc_devt), rtc->id); | |
406 | else | |
407 | pr_debug("%s: dev (%d:%d)\n", rtc->name, | |
e824290e | 408 | MAJOR(rtc_devt), rtc->id); |
e824290e AZ |
409 | } |
410 | ||
5726fb20 | 411 | void rtc_dev_del_device(struct rtc_device *rtc) |
e824290e | 412 | { |
cd966209 | 413 | if (rtc->dev.devt) |
e824290e | 414 | cdev_del(&rtc->char_dev); |
e824290e AZ |
415 | } |
416 | ||
5726fb20 | 417 | void __init rtc_dev_init(void) |
e824290e AZ |
418 | { |
419 | int err; | |
420 | ||
e824290e | 421 | err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc"); |
5726fb20 | 422 | if (err < 0) |
e824290e AZ |
423 | printk(KERN_ERR "%s: failed to allocate char dev region\n", |
424 | __FILE__); | |
e824290e AZ |
425 | } |
426 | ||
5726fb20 | 427 | void __exit rtc_dev_exit(void) |
e824290e | 428 | { |
5726fb20 DB |
429 | if (rtc_devt) |
430 | unregister_chrdev_region(rtc_devt, RTC_DEV_MAX); | |
e824290e | 431 | } |