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avr32: Reduce DataFlash bus speed to 8 MHz on ATNGW100
[linux-2.6/pdupreez.git] / drivers / rtc / rtc-s3c.c
blobe7d19b6c265af6e5a285778309d2047f46c82585
1 /* drivers/rtc/rtc-s3c.c
2 *
3 * Copyright (c) 2004,2006 Simtec Electronics
4 * Ben Dooks, <ben@simtec.co.uk>
5 * http://armlinux.simtec.co.uk/
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * S3C2410/S3C2440/S3C24XX Internal RTC Driver
12 */
13
14 #include <linux/module.h>
15 #include <linux/fs.h>
16 #include <linux/string.h>
17 #include <linux/init.h>
18 #include <linux/platform_device.h>
19 #include <linux/interrupt.h>
20 #include <linux/rtc.h>
21 #include <linux/bcd.h>
22 #include <linux/clk.h>
23 #include <linux/log2.h>
24
25 #include <mach/hardware.h>
26 #include <asm/uaccess.h>
27 #include <asm/io.h>
28 #include <asm/irq.h>
29 #include <asm/plat-s3c/regs-rtc.h>
30
31 /* I have yet to find an S3C implementation with more than one
32 * of these rtc blocks in */
33
34 static struct resource *s3c_rtc_mem;
35
36 static void __iomem *s3c_rtc_base;
37 static int s3c_rtc_alarmno = NO_IRQ;
38 static int s3c_rtc_tickno = NO_IRQ;
39
40 static DEFINE_SPINLOCK(s3c_rtc_pie_lock);
41
42 /* IRQ Handlers */
43
44 static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
45 {
46 struct rtc_device *rdev = id;
47
48 rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
49 return IRQ_HANDLED;
50 }
51
52 static irqreturn_t s3c_rtc_tickirq(int irq, void *id)
53 {
54 struct rtc_device *rdev = id;
55
56 rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);
57 return IRQ_HANDLED;
58 }
59
60 /* Update control registers */
61 static void s3c_rtc_setaie(int to)
62 {
63 unsigned int tmp;
64
65 pr_debug("%s: aie=%d\n", __func__, to);
66
67 tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
68
69 if (to)
70 tmp |= S3C2410_RTCALM_ALMEN;
71
72 writeb(tmp, s3c_rtc_base + S3C2410_RTCALM);
73 }
74
75 static int s3c_rtc_setpie(struct device *dev, int enabled)
76 {
77 unsigned int tmp;
78
79 pr_debug("%s: pie=%d\n", __func__, enabled);
80
81 spin_lock_irq(&s3c_rtc_pie_lock);
82 tmp = readb(s3c_rtc_base + S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE;
83
84 if (enabled)
85 tmp |= S3C2410_TICNT_ENABLE;
86
87 writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
88 spin_unlock_irq(&s3c_rtc_pie_lock);
89
90 return 0;
91 }
92
93 static int s3c_rtc_setfreq(struct device *dev, int freq)
94 {
95 unsigned int tmp;
96
97 spin_lock_irq(&s3c_rtc_pie_lock);
98
99 tmp = readb(s3c_rtc_base + S3C2410_TICNT) & S3C2410_TICNT_ENABLE;
100 tmp |= (128 / freq)-1;
101
102 writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
103 spin_unlock_irq(&s3c_rtc_pie_lock);
104
105 return 0;
106 }
107
108 /* Time read/write */
109
110 static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
111 {
112 unsigned int have_retried = 0;
113 void __iomem *base = s3c_rtc_base;
114
115 retry_get_time:
116 rtc_tm->tm_min = readb(base + S3C2410_RTCMIN);
117 rtc_tm->tm_hour = readb(base + S3C2410_RTCHOUR);
118 rtc_tm->tm_mday = readb(base + S3C2410_RTCDATE);
119 rtc_tm->tm_mon = readb(base + S3C2410_RTCMON);
120 rtc_tm->tm_year = readb(base + S3C2410_RTCYEAR);
121 rtc_tm->tm_sec = readb(base + S3C2410_RTCSEC);
122
123 /* the only way to work out wether the system was mid-update
124 * when we read it is to check the second counter, and if it
125 * is zero, then we re-try the entire read
126 */
127
128 if (rtc_tm->tm_sec == 0 && !have_retried) {
129 have_retried = 1;
130 goto retry_get_time;
131 }
132
133 pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
134 rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
135 rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
136
137 BCD_TO_BIN(rtc_tm->tm_sec);
138 BCD_TO_BIN(rtc_tm->tm_min);
139 BCD_TO_BIN(rtc_tm->tm_hour);
140 BCD_TO_BIN(rtc_tm->tm_mday);
141 BCD_TO_BIN(rtc_tm->tm_mon);
142 BCD_TO_BIN(rtc_tm->tm_year);
143
144 rtc_tm->tm_year += 100;
145 rtc_tm->tm_mon -= 1;
146
147 return 0;
148 }
149
150 static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
151 {
152 void __iomem *base = s3c_rtc_base;
153 int year = tm->tm_year - 100;
154
155 pr_debug("set time %02d.%02d.%02d %02d/%02d/%02d\n",
156 tm->tm_year, tm->tm_mon, tm->tm_mday,
157 tm->tm_hour, tm->tm_min, tm->tm_sec);
158
159 /* we get around y2k by simply not supporting it */
160
161 if (year < 0 || year >= 100) {
162 dev_err(dev, "rtc only supports 100 years\n");
163 return -EINVAL;
164 }
165
166 writeb(BIN2BCD(tm->tm_sec), base + S3C2410_RTCSEC);
167 writeb(BIN2BCD(tm->tm_min), base + S3C2410_RTCMIN);
168 writeb(BIN2BCD(tm->tm_hour), base + S3C2410_RTCHOUR);
169 writeb(BIN2BCD(tm->tm_mday), base + S3C2410_RTCDATE);
170 writeb(BIN2BCD(tm->tm_mon + 1), base + S3C2410_RTCMON);
171 writeb(BIN2BCD(year), base + S3C2410_RTCYEAR);
172
173 return 0;
174 }
175
176 static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
177 {
178 struct rtc_time *alm_tm = &alrm->time;
179 void __iomem *base = s3c_rtc_base;
180 unsigned int alm_en;
181
182 alm_tm->tm_sec = readb(base + S3C2410_ALMSEC);
183 alm_tm->tm_min = readb(base + S3C2410_ALMMIN);
184 alm_tm->tm_hour = readb(base + S3C2410_ALMHOUR);
185 alm_tm->tm_mon = readb(base + S3C2410_ALMMON);
186 alm_tm->tm_mday = readb(base + S3C2410_ALMDATE);
187 alm_tm->tm_year = readb(base + S3C2410_ALMYEAR);
188
189 alm_en = readb(base + S3C2410_RTCALM);
190
191 alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;
192
193 pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
194 alm_en,
195 alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
196 alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
197
198
199 /* decode the alarm enable field */
200
201 if (alm_en & S3C2410_RTCALM_SECEN)
202 BCD_TO_BIN(alm_tm->tm_sec);
203 else
204 alm_tm->tm_sec = 0xff;
205
206 if (alm_en & S3C2410_RTCALM_MINEN)
207 BCD_TO_BIN(alm_tm->tm_min);
208 else
209 alm_tm->tm_min = 0xff;
210
211 if (alm_en & S3C2410_RTCALM_HOUREN)
212 BCD_TO_BIN(alm_tm->tm_hour);
213 else
214 alm_tm->tm_hour = 0xff;
215
216 if (alm_en & S3C2410_RTCALM_DAYEN)
217 BCD_TO_BIN(alm_tm->tm_mday);
218 else
219 alm_tm->tm_mday = 0xff;
220
221 if (alm_en & S3C2410_RTCALM_MONEN) {
222 BCD_TO_BIN(alm_tm->tm_mon);
223 alm_tm->tm_mon -= 1;
224 } else {
225 alm_tm->tm_mon = 0xff;
226 }
227
228 if (alm_en & S3C2410_RTCALM_YEAREN)
229 BCD_TO_BIN(alm_tm->tm_year);
230 else
231 alm_tm->tm_year = 0xffff;
232
233 return 0;
234 }
235
236 static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
237 {
238 struct rtc_time *tm = &alrm->time;
239 void __iomem *base = s3c_rtc_base;
240 unsigned int alrm_en;
241
242 pr_debug("s3c_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
243 alrm->enabled,
244 tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
245 tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
246
247
248 alrm_en = readb(base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
249 writeb(0x00, base + S3C2410_RTCALM);
250
251 if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
252 alrm_en |= S3C2410_RTCALM_SECEN;
253 writeb(BIN2BCD(tm->tm_sec), base + S3C2410_ALMSEC);
254 }
255
256 if (tm->tm_min < 60 && tm->tm_min >= 0) {
257 alrm_en |= S3C2410_RTCALM_MINEN;
258 writeb(BIN2BCD(tm->tm_min), base + S3C2410_ALMMIN);
259 }
260
261 if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
262 alrm_en |= S3C2410_RTCALM_HOUREN;
263 writeb(BIN2BCD(tm->tm_hour), base + S3C2410_ALMHOUR);
264 }
265
266 pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
267
268 writeb(alrm_en, base + S3C2410_RTCALM);
269
270 s3c_rtc_setaie(alrm->enabled);
271
272 if (alrm->enabled)
273 enable_irq_wake(s3c_rtc_alarmno);
274 else
275 disable_irq_wake(s3c_rtc_alarmno);
276
277 return 0;
278 }
279
280 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
281 {
282 unsigned int ticnt = readb(s3c_rtc_base + S3C2410_TICNT);
283
284 seq_printf(seq, "periodic_IRQ\t: %s\n",
285 (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" );
286 return 0;
287 }
288
289 static int s3c_rtc_open(struct device *dev)
290 {
291 struct platform_device *pdev = to_platform_device(dev);
292 struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
293 int ret;
294
295 ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq,
296 IRQF_DISABLED, "s3c2410-rtc alarm", rtc_dev);
297
298 if (ret) {
299 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret);
300 return ret;
301 }
302
303 ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq,
304 IRQF_DISABLED, "s3c2410-rtc tick", rtc_dev);
305
306 if (ret) {
307 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret);
308 goto tick_err;
309 }
310
311 return ret;
312
313 tick_err:
314 free_irq(s3c_rtc_alarmno, rtc_dev);
315 return ret;
316 }
317
318 static void s3c_rtc_release(struct device *dev)
319 {
320 struct platform_device *pdev = to_platform_device(dev);
321 struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
322
323 /* do not clear AIE here, it may be needed for wake */
324
325 s3c_rtc_setpie(dev, 0);
326 free_irq(s3c_rtc_alarmno, rtc_dev);
327 free_irq(s3c_rtc_tickno, rtc_dev);
328 }
329
330 static const struct rtc_class_ops s3c_rtcops = {
331 .open = s3c_rtc_open,
332 .release = s3c_rtc_release,
333 .read_time = s3c_rtc_gettime,
334 .set_time = s3c_rtc_settime,
335 .read_alarm = s3c_rtc_getalarm,
336 .set_alarm = s3c_rtc_setalarm,
337 .irq_set_freq = s3c_rtc_setfreq,
338 .irq_set_state = s3c_rtc_setpie,
339 .proc = s3c_rtc_proc,
340 };
341
342 static void s3c_rtc_enable(struct platform_device *pdev, int en)
343 {
344 void __iomem *base = s3c_rtc_base;
345 unsigned int tmp;
346
347 if (s3c_rtc_base == NULL)
348 return;
349
350 if (!en) {
351 tmp = readb(base + S3C2410_RTCCON);
352 writeb(tmp & ~S3C2410_RTCCON_RTCEN, base + S3C2410_RTCCON);
353
354 tmp = readb(base + S3C2410_TICNT);
355 writeb(tmp & ~S3C2410_TICNT_ENABLE, base + S3C2410_TICNT);
356 } else {
357 /* re-enable the device, and check it is ok */
358
359 if ((readb(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){
360 dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
361
362 tmp = readb(base + S3C2410_RTCCON);
363 writeb(tmp|S3C2410_RTCCON_RTCEN, base+S3C2410_RTCCON);
364 }
365
366 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){
367 dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n");
368
369 tmp = readb(base + S3C2410_RTCCON);
370 writeb(tmp& ~S3C2410_RTCCON_CNTSEL, base+S3C2410_RTCCON);
371 }
372
373 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){
374 dev_info(&pdev->dev, "removing RTCCON_CLKRST\n");
375
376 tmp = readb(base + S3C2410_RTCCON);
377 writeb(tmp & ~S3C2410_RTCCON_CLKRST, base+S3C2410_RTCCON);
378 }
379 }
380 }
381
382 static int __devexit s3c_rtc_remove(struct platform_device *dev)
383 {
384 struct rtc_device *rtc = platform_get_drvdata(dev);
385
386 platform_set_drvdata(dev, NULL);
387 rtc_device_unregister(rtc);
388
389 s3c_rtc_setpie(&dev->dev, 0);
390 s3c_rtc_setaie(0);
391
392 iounmap(s3c_rtc_base);
393 release_resource(s3c_rtc_mem);
394 kfree(s3c_rtc_mem);
395
396 return 0;
397 }
398
399 static int __devinit s3c_rtc_probe(struct platform_device *pdev)
400 {
401 struct rtc_device *rtc;
402 struct resource *res;
403 int ret;
404
405 pr_debug("%s: probe=%p\n", __func__, pdev);
406
407 /* find the IRQs */
408
409 s3c_rtc_tickno = platform_get_irq(pdev, 1);
410 if (s3c_rtc_tickno < 0) {
411 dev_err(&pdev->dev, "no irq for rtc tick\n");
412 return -ENOENT;
413 }
414
415 s3c_rtc_alarmno = platform_get_irq(pdev, 0);
416 if (s3c_rtc_alarmno < 0) {
417 dev_err(&pdev->dev, "no irq for alarm\n");
418 return -ENOENT;
419 }
420
421 pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
422 s3c_rtc_tickno, s3c_rtc_alarmno);
423
424 /* get the memory region */
425
426 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
427 if (res == NULL) {
428 dev_err(&pdev->dev, "failed to get memory region resource\n");
429 return -ENOENT;
430 }
431
432 s3c_rtc_mem = request_mem_region(res->start,
433 res->end-res->start+1,
434 pdev->name);
435
436 if (s3c_rtc_mem == NULL) {
437 dev_err(&pdev->dev, "failed to reserve memory region\n");
438 ret = -ENOENT;
439 goto err_nores;
440 }
441
442 s3c_rtc_base = ioremap(res->start, res->end - res->start + 1);
443 if (s3c_rtc_base == NULL) {
444 dev_err(&pdev->dev, "failed ioremap()\n");
445 ret = -EINVAL;
446 goto err_nomap;
447 }
448
449 /* check to see if everything is setup correctly */
450
451 s3c_rtc_enable(pdev, 1);
452
453 pr_debug("s3c2410_rtc: RTCCON=%02x\n",
454 readb(s3c_rtc_base + S3C2410_RTCCON));
455
456 s3c_rtc_setfreq(&pdev->dev, 1);
457
458 /* register RTC and exit */
459
460 rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops,
461 THIS_MODULE);
462
463 if (IS_ERR(rtc)) {
464 dev_err(&pdev->dev, "cannot attach rtc\n");
465 ret = PTR_ERR(rtc);
466 goto err_nortc;
467 }
468
469 rtc->max_user_freq = 128;
470
471 platform_set_drvdata(pdev, rtc);
472 return 0;
473
474 err_nortc:
475 s3c_rtc_enable(pdev, 0);
476 iounmap(s3c_rtc_base);
477
478 err_nomap:
479 release_resource(s3c_rtc_mem);
480
481 err_nores:
482 return ret;
483 }
484
485 #ifdef CONFIG_PM
486
487 /* RTC Power management control */
488
489 static int ticnt_save;
490
491 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)
492 {
493 /* save TICNT for anyone using periodic interrupts */
494 ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);
495 s3c_rtc_enable(pdev, 0);
496 return 0;
497 }
498
499 static int s3c_rtc_resume(struct platform_device *pdev)
500 {
501 s3c_rtc_enable(pdev, 1);
502 writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
503 return 0;
504 }
505 #else
506 #define s3c_rtc_suspend NULL
507 #define s3c_rtc_resume NULL
508 #endif
509
510 static struct platform_driver s3c2410_rtcdrv = {
511 .probe = s3c_rtc_probe,
512 .remove = __devexit_p(s3c_rtc_remove),
513 .suspend = s3c_rtc_suspend,
514 .resume = s3c_rtc_resume,
515 .driver = {
516 .name = "s3c2410-rtc",
517 .owner = THIS_MODULE,
518 },
519 };
520
521 static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n";
522
523 static int __init s3c_rtc_init(void)
524 {
525 printk(banner);
526 return platform_driver_register(&s3c2410_rtcdrv);
527 }
528
529 static void __exit s3c_rtc_exit(void)
530 {
531 platform_driver_unregister(&s3c2410_rtcdrv);
532 }
533
534 module_init(s3c_rtc_init);
535 module_exit(s3c_rtc_exit);
536
537 MODULE_DESCRIPTION("Samsung S3C RTC Driver");
538 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
539 MODULE_LICENSE("GPL");
540 MODULE_ALIAS("platform:s3c2410-rtc");
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