1 /* drivers/char/s3c2410_rtc.c
2 *
3 * Copyright (c) 2004 Simtec Electronics <linux@simtec.co.uk>
4 * http://www.simtec.co.uk/products/SWLINUX/
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 version 2 as
8 * published by the Free Software Foundation.
9 *
10 * S3C2410 Internal RTC Driver
11 *
12 * Changelog:
13 * 08-Nov-2004 BJD Initial creation
14 * 12-Nov-2004 BJD Added periodic IRQ and PM code
15 * 22-Nov-2004 BJD Sign-test on alarm code to check for <0
16 */
17
18 #include <linux/module.h>
19 #include <linux/fs.h>
20 #include <linux/string.h>
21 #include <linux/init.h>
22 #include <linux/device.h>
23 #include <linux/interrupt.h>
24 #include <linux/rtc.h>
25 #include <linux/bcd.h>
26
27 #include <asm/hardware.h>
28 #include <asm/uaccess.h>
29 #include <asm/io.h>
30 #include <asm/irq.h>
31 #include <asm/rtc.h>
32
33 #include <asm/mach/time.h>
34
35 #include <asm/hardware/clock.h>
36 #include <asm/arch/regs-rtc.h>
37
38 /* need this for the RTC_AF definitions */
39 #include <linux/mc146818rtc.h>
40
41 #undef S3C2410_VA_RTC
42 #define S3C2410_VA_RTC s3c2410_rtc_base
43
44 static struct resource *s3c2410_rtc_mem;
45
46 static void __iomem *s3c2410_rtc_base;
47 static int s3c2410_rtc_alarmno = NO_IRQ;
48 static int s3c2410_rtc_tickno = NO_IRQ;
49 static int s3c2410_rtc_freq = 1;
50
51 static DEFINE_SPINLOCK(s3c2410_rtc_pie_lock);
52
53 /* IRQ Handlers */
54
55 static irqreturn_t s3c2410_rtc_alarmirq(int irq, void *id, struct pt_regs *r)
56 {
57 rtc_update(1, RTC_AF | RTC_IRQF);
58 return IRQ_HANDLED;
59 }
60
61 static irqreturn_t s3c2410_rtc_tickirq(int irq, void *id, struct pt_regs *r)
62 {
63 rtc_update(1, RTC_PF | RTC_IRQF);
64 return IRQ_HANDLED;
65 }
66
67 /* Update control registers */
68 static void s3c2410_rtc_setaie(int to)
69 {
70 unsigned int tmp;
71
72 pr_debug("%s: aie=%d\n", __FUNCTION__, to);
73
74 tmp = readb(S3C2410_RTCALM);
75
76 if (to)
77 tmp |= S3C2410_RTCALM_ALMEN;
78 else
79 tmp &= ~S3C2410_RTCALM_ALMEN;
80
81
82 writeb(tmp, S3C2410_RTCALM);
83 }
84
85 static void s3c2410_rtc_setpie(int to)
86 {
87 unsigned int tmp;
88
89 pr_debug("%s: pie=%d\n", __FUNCTION__, to);
90
91 spin_lock_irq(&s3c2410_rtc_pie_lock);
92 tmp = readb(S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE;
93
94 if (to)
95 tmp |= S3C2410_TICNT_ENABLE;
96
97 writeb(tmp, S3C2410_TICNT);
98 spin_unlock_irq(&s3c2410_rtc_pie_lock);
99 }
100
101 static void s3c2410_rtc_setfreq(int freq)
102 {
103 unsigned int tmp;
104
105 spin_lock_irq(&s3c2410_rtc_pie_lock);
106 tmp = readb(S3C2410_TICNT) & S3C2410_TICNT_ENABLE;
107
108 s3c2410_rtc_freq = freq;
109
110 tmp |= (128 / freq)-1;
111
112 writeb(tmp, S3C2410_TICNT);
113 spin_unlock_irq(&s3c2410_rtc_pie_lock);
114 }
115
116 /* Time read/write */
117
118 static void s3c2410_rtc_gettime(struct rtc_time *rtc_tm)
119 {
120 unsigned int have_retried = 0;
121
122 retry_get_time:
123 rtc_tm->tm_min = readb(S3C2410_RTCMIN);
124 rtc_tm->tm_hour = readb(S3C2410_RTCHOUR);
125 rtc_tm->tm_mday = readb(S3C2410_RTCDATE);
126 rtc_tm->tm_mon = readb(S3C2410_RTCMON);
127 rtc_tm->tm_year = readb(S3C2410_RTCYEAR);
128 rtc_tm->tm_sec = readb(S3C2410_RTCSEC);
129
130 /* the only way to work out wether the system was mid-update
131 * when we read it is to check the second counter, and if it
132 * is zero, then we re-try the entire read
133 */
134
135 if (rtc_tm->tm_sec == 0 && !have_retried) {
136 have_retried = 1;
137 goto retry_get_time;
138 }
139
140 pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
141 rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
142 rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
143
144 BCD_TO_BIN(rtc_tm->tm_sec);
145 BCD_TO_BIN(rtc_tm->tm_min);
146 BCD_TO_BIN(rtc_tm->tm_hour);
147 BCD_TO_BIN(rtc_tm->tm_mday);
148 BCD_TO_BIN(rtc_tm->tm_mon);
149 BCD_TO_BIN(rtc_tm->tm_year);
150
151 rtc_tm->tm_year += 100;
152 rtc_tm->tm_mon -= 1;
153 }
154
155
156 static int s3c2410_rtc_settime(struct rtc_time *tm)
157 {
158 /* the rtc gets round the y2k problem by just not supporting it */
159
160 if (tm->tm_year < 100)
161 return -EINVAL;
162
163 writeb(BIN2BCD(tm->tm_sec), S3C2410_RTCSEC);
164 writeb(BIN2BCD(tm->tm_min), S3C2410_RTCMIN);
165 writeb(BIN2BCD(tm->tm_hour), S3C2410_RTCHOUR);
166 writeb(BIN2BCD(tm->tm_mday), S3C2410_RTCDATE);
167 writeb(BIN2BCD(tm->tm_mon + 1), S3C2410_RTCMON);
168 writeb(BIN2BCD(tm->tm_year - 100), S3C2410_RTCYEAR);
169
170 return 0;
171 }
172
173 static void s3c2410_rtc_getalarm(struct rtc_wkalrm *alrm)
174 {
175 struct rtc_time *alm_tm = &alrm->time;
176 unsigned int alm_en;
177
178 alm_tm->tm_sec = readb(S3C2410_ALMSEC);
179 alm_tm->tm_min = readb(S3C2410_ALMMIN);
180 alm_tm->tm_hour = readb(S3C2410_ALMHOUR);
181 alm_tm->tm_mon = readb(S3C2410_ALMMON);
182 alm_tm->tm_mday = readb(S3C2410_ALMDATE);
183 alm_tm->tm_year = readb(S3C2410_ALMYEAR);
184
185 alm_en = readb(S3C2410_RTCALM);
186
187 pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
188 alm_en,
189 alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
190 alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
191
192
193 /* decode the alarm enable field */
194
195 if (alm_en & S3C2410_RTCALM_SECEN) {
196 BCD_TO_BIN(alm_tm->tm_sec);
197 } else {
198 alm_tm->tm_sec = 0xff;
199 }
200
201 if (alm_en & S3C2410_RTCALM_MINEN) {
202 BCD_TO_BIN(alm_tm->tm_min);
203 } else {
204 alm_tm->tm_min = 0xff;
205 }
206
207 if (alm_en & S3C2410_RTCALM_HOUREN) {
208 BCD_TO_BIN(alm_tm->tm_hour);
209 } else {
210 alm_tm->tm_hour = 0xff;
211 }
212
213 if (alm_en & S3C2410_RTCALM_DAYEN) {
214 BCD_TO_BIN(alm_tm->tm_mday);
215 } else {
216 alm_tm->tm_mday = 0xff;
217 }
218
219 if (alm_en & S3C2410_RTCALM_MONEN) {
220 BCD_TO_BIN(alm_tm->tm_mon);
221 alm_tm->tm_mon -= 1;
222 } else {
223 alm_tm->tm_mon = 0xff;
224 }
225
226 if (alm_en & S3C2410_RTCALM_YEAREN) {
227 BCD_TO_BIN(alm_tm->tm_year);
228 } else {
229 alm_tm->tm_year = 0xffff;
230 }
231
232 /* todo - set alrm->enabled ? */
233 }
234
235 static int s3c2410_rtc_setalarm(struct rtc_wkalrm *alrm)
236 {
237 struct rtc_time *tm = &alrm->time;
238 unsigned int alrm_en;
239
240 pr_debug("s3c2410_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
241 alrm->enabled,
242 tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
243 tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
244
245 if (alrm->enabled || 1) {
246 alrm_en = readb(S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
247 writeb(0x00, S3C2410_RTCALM);
248
249 if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
250 alrm_en |= S3C2410_RTCALM_SECEN;
251 writeb(BIN2BCD(tm->tm_sec), S3C2410_ALMSEC);
252 }
253
254 if (tm->tm_min < 60 && tm->tm_min >= 0) {
255 alrm_en |= S3C2410_RTCALM_MINEN;
256 writeb(BIN2BCD(tm->tm_min), S3C2410_ALMMIN);
257 }
258
259 if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
260 alrm_en |= S3C2410_RTCALM_HOUREN;
261 writeb(BIN2BCD(tm->tm_hour), S3C2410_ALMHOUR);
262 }
263
264 pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
265
266 writeb(alrm_en, S3C2410_RTCALM);
267 enable_irq_wake(s3c2410_rtc_alarmno);
268 } else {
269 alrm_en = readb(S3C2410_RTCALM);
270 alrm_en &= ~S3C2410_RTCALM_ALMEN;
271 writeb(alrm_en, S3C2410_RTCALM);
272 disable_irq_wake(s3c2410_rtc_alarmno);
273 }
274
275 return 0;
276 }
277
278 static int s3c2410_rtc_ioctl(unsigned int cmd, unsigned long arg)
279 {
280 switch (cmd) {
281 case RTC_AIE_OFF:
282 case RTC_AIE_ON:
283 s3c2410_rtc_setaie((cmd == RTC_AIE_ON) ? 1 : 0);
284 return 0;
285
286 case RTC_PIE_OFF:
287 case RTC_PIE_ON:
288 s3c2410_rtc_setpie((cmd == RTC_PIE_ON) ? 1 : 0);
289 return 0;
290
291 case RTC_IRQP_READ:
292 return put_user(s3c2410_rtc_freq, (unsigned long __user *)arg);
293
294 case RTC_IRQP_SET:
295 if (arg < 1 || arg > 64)
296 return -EINVAL;
297
298 if (!capable(CAP_SYS_RESOURCE))
299 return -EACCES;
300
301 /* check for power of 2 */
302
303 if ((arg & (arg-1)) != 0)
304 return -EINVAL;
305
306 pr_debug("s3c2410_rtc: setting frequency %ld\n", arg);
307
308 s3c2410_rtc_setfreq(arg);
309 return 0;
310
311 case RTC_UIE_ON:
312 case RTC_UIE_OFF:
313 return -EINVAL;
314 }
315
316 return -EINVAL;
317 }
318
319 static int s3c2410_rtc_proc(char *buf)
320 {
321 unsigned int rtcalm = readb(S3C2410_RTCALM);
322 unsigned int ticnt = readb (S3C2410_TICNT);
323 char *p = buf;
324
325 p += sprintf(p, "alarm_IRQ\t: %s\n",
326 (rtcalm & S3C2410_RTCALM_ALMEN) ? "yes" : "no" );
327 p += sprintf(p, "periodic_IRQ\t: %s\n",
328 (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" );
329 p += sprintf(p, "periodic_freq\t: %d\n", s3c2410_rtc_freq);
330
331 return p - buf;
332 }
333
334 static int s3c2410_rtc_open(void)
335 {
336 int ret;
337
338 ret = request_irq(s3c2410_rtc_alarmno, s3c2410_rtc_alarmirq,
339 SA_INTERRUPT, "s3c2410-rtc alarm", NULL);
340
341 if (ret)
342 printk(KERN_ERR "IRQ%d already in use\n", s3c2410_rtc_alarmno);
343
344 ret = request_irq(s3c2410_rtc_tickno, s3c2410_rtc_tickirq,
345 SA_INTERRUPT, "s3c2410-rtc tick", NULL);
346
347 if (ret) {
348 printk(KERN_ERR "IRQ%d already in use\n", s3c2410_rtc_tickno);
349 goto tick_err;
350 }
351
352 return ret;
353
354 tick_err:
355 free_irq(s3c2410_rtc_alarmno, NULL);
356 return ret;
357 }
358
359 static void s3c2410_rtc_release(void)
360 {
361 /* do not clear AIE here, it may be needed for wake */
362
363 s3c2410_rtc_setpie(0);
364 free_irq(s3c2410_rtc_alarmno, NULL);
365 free_irq(s3c2410_rtc_tickno, NULL);
366 }
367
368 static struct rtc_ops s3c2410_rtcops = {
369 .owner = THIS_MODULE,
370 .open = s3c2410_rtc_open,
371 .release = s3c2410_rtc_release,
372 .ioctl = s3c2410_rtc_ioctl,
373 .read_time = s3c2410_rtc_gettime,
374 .set_time = s3c2410_rtc_settime,
375 .read_alarm = s3c2410_rtc_getalarm,
376 .set_alarm = s3c2410_rtc_setalarm,
377 .proc = s3c2410_rtc_proc,
378 };
379
380 static void s3c2410_rtc_enable(struct device *dev, int en)
381 {
382 unsigned int tmp;
383
384 if (s3c2410_rtc_base == NULL)
385 return;
386
387 if (!en) {
388 tmp = readb(S3C2410_RTCCON);
389 writeb(tmp & ~S3C2410_RTCCON_RTCEN, S3C2410_RTCCON);
390
391 tmp = readb(S3C2410_TICNT);
392 writeb(tmp & ~S3C2410_TICNT_ENABLE, S3C2410_TICNT);
393 } else {
394 /* re-enable the device, and check it is ok */
395
396 if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){
397 dev_info(dev, "rtc disabled, re-enabling\n");
398
399 tmp = readb(S3C2410_RTCCON);
400 writeb(tmp | S3C2410_RTCCON_RTCEN , S3C2410_RTCCON);
401 }
402
403 if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){
404 dev_info(dev, "removing S3C2410_RTCCON_CNTSEL\n");
405
406 tmp = readb(S3C2410_RTCCON);
407 writeb(tmp& ~S3C2410_RTCCON_CNTSEL , S3C2410_RTCCON);
408 }
409
410 if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){
411 dev_info(dev, "removing S3C2410_RTCCON_CLKRST\n");
412
413 tmp = readb(S3C2410_RTCCON);
414 writeb(tmp & ~S3C2410_RTCCON_CLKRST, S3C2410_RTCCON);
415 }
416 }
417 }
418
419 static int s3c2410_rtc_remove(struct device *dev)
420 {
421 unregister_rtc(&s3c2410_rtcops);
422
423 s3c2410_rtc_setpie(0);
424 s3c2410_rtc_setaie(0);
425
426 if (s3c2410_rtc_mem != NULL) {
427 pr_debug("s3c2410_rtc: releasing s3c2410_rtc_mem\n");
428 iounmap(s3c2410_rtc_base);
429 release_resource(s3c2410_rtc_mem);
430 kfree(s3c2410_rtc_mem);
431 }
432
433 return 0;
434 }
435
436 static int s3c2410_rtc_probe(struct device *dev)
437 {
438 struct platform_device *pdev = to_platform_device(dev);
439 struct resource *res;
440 int ret;
441
442 pr_debug("%s: probe=%p, device=%p\n", __FUNCTION__, pdev, dev);
443
444 /* find the IRQs */
445
446 s3c2410_rtc_tickno = platform_get_irq(pdev, 1);
447 if (s3c2410_rtc_tickno <= 0) {
448 dev_err(dev, "no irq for rtc tick\n");
449 return -ENOENT;
450 }
451
452 s3c2410_rtc_alarmno = platform_get_irq(pdev, 0);
453 if (s3c2410_rtc_alarmno <= 0) {
454 dev_err(dev, "no irq for alarm\n");
455 return -ENOENT;
456 }
457
458 pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
459 s3c2410_rtc_tickno, s3c2410_rtc_alarmno);
460
461 /* get the memory region */
462
463 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
464 if (res == NULL) {
465 dev_err(dev, "failed to get memory region resource\n");
466 return -ENOENT;
467 }
468
469 s3c2410_rtc_mem = request_mem_region(res->start, res->end-res->start+1,
470 pdev->name);
471
472 if (s3c2410_rtc_mem == NULL) {
473 dev_err(dev, "failed to reserve memory region\n");
474 ret = -ENOENT;
475 goto exit_err;
476 }
477
478 s3c2410_rtc_base = ioremap(res->start, res->end - res->start + 1);
479 if (s3c2410_rtc_base == NULL) {
480 dev_err(dev, "failed ioremap()\n");
481 ret = -EINVAL;
482 goto exit_err;
483 }
484
485 s3c2410_rtc_mem = res;
486 pr_debug("s3c2410_rtc_base=%p\n", s3c2410_rtc_base);
487
488 pr_debug("s3c2410_rtc: RTCCON=%02x\n", readb(S3C2410_RTCCON));
489
490 /* check to see if everything is setup correctly */
491
492 s3c2410_rtc_enable(dev, 1);
493
494 pr_debug("s3c2410_rtc: RTCCON=%02x\n", readb(S3C2410_RTCCON));
495
496 s3c2410_rtc_setfreq(s3c2410_rtc_freq);
497
498 /* register RTC and exit */
499
500 register_rtc(&s3c2410_rtcops);
501 return 0;
502
503 exit_err:
504 dev_err(dev, "error %d during initialisation\n", ret);
505
506 return ret;
507 }
508
509 #ifdef CONFIG_PM
510
511 /* S3C2410 RTC Power management control */
512
513 static struct timespec s3c2410_rtc_delta;
514
515 static int ticnt_save;
516
517 static int s3c2410_rtc_suspend(struct device *dev, u32 state, u32 level)
518 {
519 struct rtc_time tm;
520 struct timespec time;
521
522 time.tv_nsec = 0;
523
524 if (level == SUSPEND_POWER_DOWN) {
525 /* save TICNT for anyone using periodic interrupts */
526
527 ticnt_save = readb(S3C2410_TICNT);
528
529 /* calculate time delta for suspend */
530
531 s3c2410_rtc_gettime(&tm);
532 rtc_tm_to_time(&tm, &time.tv_sec);
533 save_time_delta(&s3c2410_rtc_delta, &time);
534 s3c2410_rtc_enable(dev, 0);
535 }
536
537 return 0;
538 }
539
540 static int s3c2410_rtc_resume(struct device *dev, u32 level)
541 {
542 struct rtc_time tm;
543 struct timespec time;
544
545 time.tv_nsec = 0;
546
547 s3c2410_rtc_enable(dev, 1);
548 s3c2410_rtc_gettime(&tm);
549 rtc_tm_to_time(&tm, &time.tv_sec);
550 restore_time_delta(&s3c2410_rtc_delta, &time);
551
552 writeb(ticnt_save, S3C2410_TICNT);
553 return 0;
554 }
555 #else
556 #define s3c2410_rtc_suspend NULL
557 #define s3c2410_rtc_resume NULL
558 #endif
559
560 static struct device_driver s3c2410_rtcdrv = {
561 .name = "s3c2410-rtc",
562 .bus = &platform_bus_type,
563 .probe = s3c2410_rtc_probe,
564 .remove = s3c2410_rtc_remove,
565 .suspend = s3c2410_rtc_suspend,
566 .resume = s3c2410_rtc_resume,
567 };
568
569 static char __initdata banner[] = "S3C2410 RTC, (c) 2004 Simtec Electronics\n";
570
571 static int __init s3c2410_rtc_init(void)
572 {
573 printk(banner);
574 return driver_register(&s3c2410_rtcdrv);
575 }
576
577 static void __exit s3c2410_rtc_exit(void)
578 {
579 driver_unregister(&s3c2410_rtcdrv);
580 }
581
582 module_init(s3c2410_rtc_init);
583 module_exit(s3c2410_rtc_exit);
584
585 MODULE_DESCRIPTION("S3C24XX RTC Driver");
586 MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
587 MODULE_LICENSE("GPL");
588
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