tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Driver for NEC VR4100 series Real Time Clock unit.
3 *
4 * Copyright (C) 2003-2005 Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20#include <linux/device.h>
21#include <linux/fs.h>
22#include <linux/init.h>
23#include <linux/ioport.h>
24#include <linux/irq.h>
25#include <linux/mc146818rtc.h>
26#include <linux/miscdevice.h>
27#include <linux/module.h>
28#include <linux/poll.h>
29#include <linux/rtc.h>
30#include <linux/spinlock.h>
31#include <linux/types.h>
32#include <linux/wait.h>
33
34#include <asm/div64.h>
35#include <asm/io.h>
36#include <asm/time.h>
37#include <asm/uaccess.h>
38#include <asm/vr41xx/vr41xx.h>
39
40MODULE_AUTHOR("Yoichi Yuasa <yuasa@hh.iij4u.or.jp>");
41MODULE_DESCRIPTION("NEC VR4100 series RTC driver");
42MODULE_LICENSE("GPL");
43
44#define RTC1_TYPE1_START 0x0b0000c0UL
45#define RTC1_TYPE1_END 0x0b0000dfUL
46#define RTC2_TYPE1_START 0x0b0001c0UL
47#define RTC2_TYPE1_END 0x0b0001dfUL
48
49#define RTC1_TYPE2_START 0x0f000100UL
50#define RTC1_TYPE2_END 0x0f00011fUL
51#define RTC2_TYPE2_START 0x0f000120UL
52#define RTC2_TYPE2_END 0x0f00013fUL
53
54#define RTC1_SIZE 0x20
55#define RTC2_SIZE 0x20
56
57/* RTC 1 registers */
58#define ETIMELREG 0x00
59#define ETIMEMREG 0x02
60#define ETIMEHREG 0x04
61/* RFU */
62#define ECMPLREG 0x08
63#define ECMPMREG 0x0a
64#define ECMPHREG 0x0c
65/* RFU */
66#define RTCL1LREG 0x10
67#define RTCL1HREG 0x12
68#define RTCL1CNTLREG 0x14
69#define RTCL1CNTHREG 0x16
70#define RTCL2LREG 0x18
71#define RTCL2HREG 0x1a
72#define RTCL2CNTLREG 0x1c
73#define RTCL2CNTHREG 0x1e
74
75/* RTC 2 registers */
76#define TCLKLREG 0x00
77#define TCLKHREG 0x02
78#define TCLKCNTLREG 0x04
79#define TCLKCNTHREG 0x06
80/* RFU */
81#define RTCINTREG 0x1e
82 #define TCLOCK_INT 0x08
83 #define RTCLONG2_INT 0x04
84 #define RTCLONG1_INT 0x02
85 #define ELAPSEDTIME_INT 0x01
86
87#define RTC_FREQUENCY 32768
88#define MAX_PERIODIC_RATE 6553
89#define MAX_USER_PERIODIC_RATE 64
90
91static void __iomem *rtc1_base;
92static void __iomem *rtc2_base;
93
94#define rtc1_read(offset) readw(rtc1_base + (offset))
95#define rtc1_write(offset, value) writew((value), rtc1_base + (offset))
96
97#define rtc2_read(offset) readw(rtc2_base + (offset))
98#define rtc2_write(offset, value) writew((value), rtc2_base + (offset))
99
100static unsigned long epoch = 1970; /* Jan 1 1970 00:00:00 */
101
102static spinlock_t rtc_task_lock;
103static wait_queue_head_t rtc_wait;
104static unsigned long rtc_irq_data;
105static struct fasync_struct *rtc_async_queue;
106static rtc_task_t *rtc_callback;
107static char rtc_name[] = "RTC";
108static unsigned long periodic_frequency;
109static unsigned long periodic_count;
110
111typedef enum {
112 RTC_RELEASE,
113 RTC_OPEN,
114} rtc_status_t;
115
116static rtc_status_t rtc_status;
117
118typedef enum {
119 FUNCTION_RTC_IOCTL,
120 FUNCTION_RTC_CONTROL,
121} rtc_callfrom_t;
122
123struct resource rtc_resource[2] = {
124 { .name = rtc_name,
125 .flags = IORESOURCE_MEM, },
126 { .name = rtc_name,
127 .flags = IORESOURCE_MEM, },
128};
129
130#define RTC_NUM_RESOURCES sizeof(rtc_resource) / sizeof(struct resource)
131
132static inline unsigned long read_elapsed_second(void)
133{
134 unsigned long first_low, first_mid, first_high;
135 unsigned long second_low, second_mid, second_high;
136
137 do {
138 first_low = rtc1_read(ETIMELREG);
139 first_mid = rtc1_read(ETIMEMREG);
140 first_high = rtc1_read(ETIMEHREG);
141 second_low = rtc1_read(ETIMELREG);
142 second_mid = rtc1_read(ETIMEMREG);
143 second_high = rtc1_read(ETIMEHREG);
144 } while (first_low != second_low || first_mid != second_mid ||
145 first_high != second_high);
146
147 return (first_high << 17) | (first_mid << 1) | (first_low >> 15);
148}
149
150static inline void write_elapsed_second(unsigned long sec)
151{
152 spin_lock_irq(&rtc_lock);
153
154 rtc1_write(ETIMELREG, (uint16_t)(sec << 15));
155 rtc1_write(ETIMEMREG, (uint16_t)(sec >> 1));
156 rtc1_write(ETIMEHREG, (uint16_t)(sec >> 17));
157
158 spin_unlock_irq(&rtc_lock);
159}
160
161static void set_alarm(struct rtc_time *time)
162{
163 unsigned long alarm_sec;
164
165 alarm_sec = mktime(time->tm_year + 1900, time->tm_mon + 1, time->tm_mday,
166 time->tm_hour, time->tm_min, time->tm_sec);
167
168 spin_lock_irq(&rtc_lock);
169
170 rtc1_write(ECMPLREG, (uint16_t)(alarm_sec << 15));
171 rtc1_write(ECMPMREG, (uint16_t)(alarm_sec >> 1));
172 rtc1_write(ECMPHREG, (uint16_t)(alarm_sec >> 17));
173
174 spin_unlock_irq(&rtc_lock);
175}
176
177static void read_alarm(struct rtc_time *time)
178{
179 unsigned long low, mid, high;
180
181 spin_lock_irq(&rtc_lock);
182
183 low = rtc1_read(ECMPLREG);
184 mid = rtc1_read(ECMPMREG);
185 high = rtc1_read(ECMPHREG);
186
187 spin_unlock_irq(&rtc_lock);
188
189 to_tm((high << 17) | (mid << 1) | (low >> 15), time);
190 time->tm_year -= 1900;
191}
192
193static void read_time(struct rtc_time *time)
194{
195 unsigned long epoch_sec, elapsed_sec;
196
197 epoch_sec = mktime(epoch, 1, 1, 0, 0, 0);
198 elapsed_sec = read_elapsed_second();
199
200 to_tm(epoch_sec + elapsed_sec, time);
201 time->tm_year -= 1900;
202}
203
204static void set_time(struct rtc_time *time)
205{
206 unsigned long epoch_sec, current_sec;
207
208 epoch_sec = mktime(epoch, 1, 1, 0, 0, 0);
209 current_sec = mktime(time->tm_year + 1900, time->tm_mon + 1, time->tm_mday,
210 time->tm_hour, time->tm_min, time->tm_sec);
211
212 write_elapsed_second(current_sec - epoch_sec);
213}
214
215static ssize_t rtc_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
216{
217 DECLARE_WAITQUEUE(wait, current);
218 unsigned long irq_data;
219 int retval = 0;
220
221 if (count != sizeof(unsigned int) && count != sizeof(unsigned long))
222 return -EINVAL;
223
224 add_wait_queue(&rtc_wait, &wait);
225
226 do {
227 __set_current_state(TASK_INTERRUPTIBLE);
228
229 spin_lock_irq(&rtc_lock);
230 irq_data = rtc_irq_data;
231 rtc_irq_data = 0;
232 spin_unlock_irq(&rtc_lock);
233
234 if (irq_data != 0)
235 break;
236
237 if (file->f_flags & O_NONBLOCK) {
238 retval = -EAGAIN;
239 break;
240 }
241
242 if (signal_pending(current)) {
243 retval = -ERESTARTSYS;
244 break;
245 }
246 } while (1);
247
248 if (retval == 0) {
249 if (count == sizeof(unsigned int)) {
250 retval = put_user(irq_data, (unsigned int __user *)buf);
251 if (retval == 0)
252 retval = sizeof(unsigned int);
253 } else {
254 retval = put_user(irq_data, (unsigned long __user *)buf);
255 if (retval == 0)
256 retval = sizeof(unsigned long);
257 }
258
259 }
260
261 __set_current_state(TASK_RUNNING);
262 remove_wait_queue(&rtc_wait, &wait);
263
264 return retval;
265}
266
267static unsigned int rtc_poll(struct file *file, struct poll_table_struct *table)
268{
269 poll_wait(file, &rtc_wait, table);
270
271 if (rtc_irq_data != 0)
272 return POLLIN | POLLRDNORM;
273
274 return 0;
275}
276
277static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, rtc_callfrom_t from)
278{
279 struct rtc_time time;
280 unsigned long count;
281
282 switch (cmd) {
283 case RTC_AIE_ON:
284 enable_irq(ELAPSEDTIME_IRQ);
285 break;
286 case RTC_AIE_OFF:
287 disable_irq(ELAPSEDTIME_IRQ);
288 break;
289 case RTC_PIE_ON:
290 enable_irq(RTCLONG1_IRQ);
291 break;
292 case RTC_PIE_OFF:
293 disable_irq(RTCLONG1_IRQ);
294 break;
295 case RTC_ALM_SET:
296 if (copy_from_user(&time, (struct rtc_time __user *)arg,
297 sizeof(struct rtc_time)))
298 return -EFAULT;
299
300 set_alarm(&time);
301 break;
302 case RTC_ALM_READ:
303 memset(&time, 0, sizeof(struct rtc_time));
304 read_alarm(&time);
305 break;
306 case RTC_RD_TIME:
307 memset(&time, 0, sizeof(struct rtc_time));
308 read_time(&time);
309 if (copy_to_user((void __user *)arg, &time, sizeof(struct rtc_time)))
310 return -EFAULT;
311 break;
312 case RTC_SET_TIME:
313 if (capable(CAP_SYS_TIME) == 0)
314 return -EACCES;
315
316 if (copy_from_user(&time, (struct rtc_time __user *)arg,
317 sizeof(struct rtc_time)))
318 return -EFAULT;
319
320 set_time(&time);
321 break;
322 case RTC_IRQP_READ:
323 return put_user(periodic_frequency, (unsigned long __user *)arg);
324 break;
325 case RTC_IRQP_SET:
326 if (arg > MAX_PERIODIC_RATE)
327 return -EINVAL;
328
329 if (from == FUNCTION_RTC_IOCTL && arg > MAX_USER_PERIODIC_RATE &&
330 capable(CAP_SYS_RESOURCE) == 0)
331 return -EACCES;
332
333 periodic_frequency = arg;
334
335 count = RTC_FREQUENCY;
336 do_div(count, arg);
337
338 periodic_count = count;
339
340 spin_lock_irq(&rtc_lock);
341
342 rtc1_write(RTCL1LREG, count);
343 rtc1_write(RTCL1HREG, count >> 16);
344
345 spin_unlock_irq(&rtc_lock);
346 break;
347 case RTC_EPOCH_READ:
348 return put_user(epoch, (unsigned long __user *)arg);
349 case RTC_EPOCH_SET:
350 /* Doesn't support before 1900 */
351 if (arg < 1900)
352 return -EINVAL;
353
354 if (capable(CAP_SYS_TIME) == 0)
355 return -EACCES;
356
357 epoch = arg;
358 break;
359 default:
360 return -EINVAL;
361 }
362
363 return 0;
364}
365
366static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
367 unsigned long arg)
368{
369 return rtc_do_ioctl(cmd, arg, FUNCTION_RTC_IOCTL);
370}
371
372static int rtc_open(struct inode *inode, struct file *file)
373{
374 spin_lock_irq(&rtc_lock);
375
376 if (rtc_status == RTC_OPEN) {
377 spin_unlock_irq(&rtc_lock);
378 return -EBUSY;
379 }
380
381 rtc_status = RTC_OPEN;
382 rtc_irq_data = 0;
383
384 spin_unlock_irq(&rtc_lock);
385
386 return 0;
387}
388
389static int rtc_release(struct inode *inode, struct file *file)
390{
391 if (file->f_flags & FASYNC)
392 (void)fasync_helper(-1, file, 0, &rtc_async_queue);
393
394 spin_lock_irq(&rtc_lock);
395
396 rtc1_write(ECMPLREG, 0);
397 rtc1_write(ECMPMREG, 0);
398 rtc1_write(ECMPHREG, 0);
399 rtc1_write(RTCL1LREG, 0);
400 rtc1_write(RTCL1HREG, 0);
401
402 rtc_status = RTC_RELEASE;
403
404 spin_unlock_irq(&rtc_lock);
405
406 disable_irq(ELAPSEDTIME_IRQ);
407 disable_irq(RTCLONG1_IRQ);
408
409 return 0;
410}
411
412static int rtc_fasync(int fd, struct file *file, int on)
413{
414 return fasync_helper(fd, file, on, &rtc_async_queue);
415}
416
417static struct file_operations rtc_fops = {
418 .owner = THIS_MODULE,
419 .llseek = no_llseek,
420 .read = rtc_read,
421 .poll = rtc_poll,
422 .ioctl = rtc_ioctl,
423 .open = rtc_open,
424 .release = rtc_release,
425 .fasync = rtc_fasync,
426};
427
428static irqreturn_t elapsedtime_interrupt(int irq, void *dev_id, struct pt_regs *regs)
429{
430 spin_lock(&rtc_lock);
431 rtc2_write(RTCINTREG, ELAPSEDTIME_INT);
432
433 rtc_irq_data += 0x100;
434 rtc_irq_data &= ~0xff;
435 rtc_irq_data |= RTC_AF;
436 spin_unlock(&rtc_lock);
437
438 spin_lock(&rtc_lock);
439 if (rtc_callback)
440 rtc_callback->func(rtc_callback->private_data);
441 spin_unlock(&rtc_lock);
442
443 wake_up_interruptible(&rtc_wait);
444
445 kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);
446
447 return IRQ_HANDLED;
448}
449
450static irqreturn_t rtclong1_interrupt(int irq, void *dev_id, struct pt_regs *regs)
451{
452 unsigned long count = periodic_count;
453
454 spin_lock(&rtc_lock);
455 rtc2_write(RTCINTREG, RTCLONG1_INT);
456
457 rtc1_write(RTCL1LREG, count);
458 rtc1_write(RTCL1HREG, count >> 16);
459
460 rtc_irq_data += 0x100;
461 rtc_irq_data &= ~0xff;
462 rtc_irq_data |= RTC_PF;
463 spin_unlock(&rtc_lock);
464
465 spin_lock(&rtc_task_lock);
466 if (rtc_callback)
467 rtc_callback->func(rtc_callback->private_data);
468 spin_unlock(&rtc_task_lock);
469
470 wake_up_interruptible(&rtc_wait);
471
472 kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);
473
474 return IRQ_HANDLED;
475}
476
477int rtc_register(rtc_task_t *task)
478{
479 if (task == NULL || task->func == NULL)
480 return -EINVAL;
481
482 spin_lock_irq(&rtc_lock);
483 if (rtc_status == RTC_OPEN) {
484 spin_unlock_irq(&rtc_lock);
485 return -EBUSY;
486 }
487
488 spin_lock(&rtc_task_lock);
489 if (rtc_callback != NULL) {
490 spin_unlock(&rtc_task_lock);
491 spin_unlock_irq(&rtc_task_lock);
492 return -EBUSY;
493 }
494
495 rtc_callback = task;
496 spin_unlock(&rtc_task_lock);
497
498 rtc_status = RTC_OPEN;
499
500 spin_unlock_irq(&rtc_lock);
501
502 return 0;
503}
504
505EXPORT_SYMBOL_GPL(rtc_register);
506
507int rtc_unregister(rtc_task_t *task)
508{
509 spin_lock_irq(&rtc_task_lock);
510 if (task == NULL || rtc_callback != task) {
511 spin_unlock_irq(&rtc_task_lock);
512 return -ENXIO;
513 }
514
515 spin_lock(&rtc_lock);
516
517 rtc1_write(ECMPLREG, 0);
518 rtc1_write(ECMPMREG, 0);
519 rtc1_write(ECMPHREG, 0);
520 rtc1_write(RTCL1LREG, 0);
521 rtc1_write(RTCL1HREG, 0);
522
523 rtc_status = RTC_RELEASE;
524
525 spin_unlock(&rtc_lock);
526
527 rtc_callback = NULL;
528
529 spin_unlock_irq(&rtc_task_lock);
530
531 disable_irq(ELAPSEDTIME_IRQ);
532 disable_irq(RTCLONG1_IRQ);
533
534 return 0;
535}
536
537EXPORT_SYMBOL_GPL(rtc_unregister);
538
539int rtc_control(rtc_task_t *task, unsigned int cmd, unsigned long arg)
540{
541 int retval = 0;
542
543 spin_lock_irq(&rtc_task_lock);
544
545 if (rtc_callback != task)
546 retval = -ENXIO;
547 else
548 rtc_do_ioctl(cmd, arg, FUNCTION_RTC_CONTROL);
549
550 spin_unlock_irq(&rtc_task_lock);
551
552 return retval;
553}
554
555EXPORT_SYMBOL_GPL(rtc_control);
556
557static struct miscdevice rtc_miscdevice = {
558 .minor = RTC_MINOR,
559 .name = rtc_name,
560 .fops = &rtc_fops,
561};
562
563static int rtc_probe(struct device *dev)
564{
565 struct platform_device *pdev;
566 unsigned int irq;
567 int retval;
568
569 pdev = to_platform_device(dev);
570 if (pdev->num_resources != 2)
571 return -EBUSY;
572
573 rtc1_base = ioremap(pdev->resource[0].start, RTC1_SIZE);
574 if (rtc1_base == NULL)
575 return -EBUSY;
576
577 rtc2_base = ioremap(pdev->resource[1].start, RTC2_SIZE);
578 if (rtc2_base == NULL) {
579 iounmap(rtc1_base);
580 rtc1_base = NULL;
581 return -EBUSY;
582 }
583
584 retval = misc_register(&rtc_miscdevice);
585 if (retval < 0) {
586 iounmap(rtc1_base);
587 iounmap(rtc2_base);
588 rtc1_base = NULL;
589 rtc2_base = NULL;
590 return retval;
591 }
592
593 spin_lock_irq(&rtc_lock);
594
595 rtc1_write(ECMPLREG, 0);
596 rtc1_write(ECMPMREG, 0);
597 rtc1_write(ECMPHREG, 0);
598 rtc1_write(RTCL1LREG, 0);
599 rtc1_write(RTCL1HREG, 0);
600
601 rtc_status = RTC_RELEASE;
602 rtc_irq_data = 0;
603
604 spin_unlock_irq(&rtc_lock);
605
606 init_waitqueue_head(&rtc_wait);
607
608 irq = ELAPSEDTIME_IRQ;
609 retval = request_irq(irq, elapsedtime_interrupt, SA_INTERRUPT,
610 "elapsed_time", NULL);
611 if (retval == 0) {
612 irq = RTCLONG1_IRQ;
613 retval = request_irq(irq, rtclong1_interrupt, SA_INTERRUPT,
614 "rtclong1", NULL);
615 }
616
617 if (retval < 0) {
618 printk(KERN_ERR "rtc: IRQ%d is busy\n", irq);
619 if (irq == RTCLONG1_IRQ)
620 free_irq(ELAPSEDTIME_IRQ, NULL);
621 iounmap(rtc1_base);
622 iounmap(rtc2_base);
623 rtc1_base = NULL;
624 rtc2_base = NULL;
625 return retval;
626 }
627
628 disable_irq(ELAPSEDTIME_IRQ);
629 disable_irq(RTCLONG1_IRQ);
630
631 spin_lock_init(&rtc_task_lock);
632
633 printk(KERN_INFO "rtc: Real Time Clock of NEC VR4100 series\n");
634
635 return 0;
636}
637
638static int rtc_remove(struct device *dev)
639{
640 int retval;
641
642 retval = misc_deregister(&rtc_miscdevice);
643 if (retval < 0)
644 return retval;
645
646 free_irq(ELAPSEDTIME_IRQ, NULL);
647 free_irq(RTCLONG1_IRQ, NULL);
648 if (rtc1_base != NULL)
649 iounmap(rtc1_base);
650 if (rtc2_base != NULL)
651 iounmap(rtc2_base);
652
653 return 0;
654}
655
656static struct platform_device *rtc_platform_device;
657
658static struct device_driver rtc_device_driver = {
659 .name = rtc_name,
660 .bus = &platform_bus_type,
661 .probe = rtc_probe,
662 .remove = rtc_remove,
663};
664
665static int __devinit vr41xx_rtc_init(void)
666{
667 int retval;
668
669 switch (current_cpu_data.cputype) {
670 case CPU_VR4111:
671 case CPU_VR4121:
672 rtc_resource[0].start = RTC1_TYPE1_START;
673 rtc_resource[0].end = RTC1_TYPE1_END;
674 rtc_resource[1].start = RTC2_TYPE1_START;
675 rtc_resource[1].end = RTC2_TYPE1_END;
676 break;
677 case CPU_VR4122:
678 case CPU_VR4131:
679 case CPU_VR4133:
680 rtc_resource[0].start = RTC1_TYPE2_START;
681 rtc_resource[0].end = RTC1_TYPE2_END;
682 rtc_resource[1].start = RTC2_TYPE2_START;
683 rtc_resource[1].end = RTC2_TYPE2_END;
684 break;
685 default:
686 return -ENODEV;
687 break;
688 }
689
690 rtc_platform_device = platform_device_register_simple("RTC", -1, rtc_resource, RTC_NUM_RESOURCES);
691 if (IS_ERR(rtc_platform_device))
692 return PTR_ERR(rtc_platform_device);
693
694 retval = driver_register(&rtc_device_driver);
695 if (retval < 0)
696 platform_device_unregister(rtc_platform_device);
697
698 return retval;
699}
700
701static void __devexit vr41xx_rtc_exit(void)
702{
703 driver_unregister(&rtc_device_driver);
704
705 platform_device_unregister(rtc_platform_device);
706}
707
708module_init(vr41xx_rtc_init);
709module_exit(vr41xx_rtc_exit);