blob: 9de8d67f4f8d8ac71bcbc4c198d4b496d8c4dc27 [file] [log] [blame]
David Brownelldb68b182006-12-06 20:38:36 -08001/*
2 * TI OMAP1 Real Time Clock interface for Linux
3 *
4 * Copyright (C) 2003 MontaVista Software, Inc.
5 * Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com>
6 *
7 * Copyright (C) 2006 David Brownell (new RTC framework)
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 */
14
15#include <linux/kernel.h>
16#include <linux/init.h>
17#include <linux/module.h>
18#include <linux/ioport.h>
19#include <linux/delay.h>
20#include <linux/rtc.h>
21#include <linux/bcd.h>
22#include <linux/platform_device.h>
23
24#include <asm/io.h>
25#include <asm/mach/time.h>
26
27
28/* The OMAP1 RTC is a year/month/day/hours/minutes/seconds BCD clock
29 * with century-range alarm matching, driven by the 32kHz clock.
30 *
31 * The main user-visible ways it differs from PC RTCs are by omitting
32 * "don't care" alarm fields and sub-second periodic IRQs, and having
33 * an autoadjust mechanism to calibrate to the true oscillator rate.
34 *
35 * Board-specific wiring options include using split power mode with
36 * RTC_OFF_NOFF used as the reset signal (so the RTC won't be reset),
37 * and wiring RTC_WAKE_INT (so the RTC alarm can wake the system from
38 * low power modes). See the BOARD-SPECIFIC CUSTOMIZATION comment.
39 */
40
41#define OMAP_RTC_BASE 0xfffb4800
42
43/* RTC registers */
44#define OMAP_RTC_SECONDS_REG 0x00
45#define OMAP_RTC_MINUTES_REG 0x04
46#define OMAP_RTC_HOURS_REG 0x08
47#define OMAP_RTC_DAYS_REG 0x0C
48#define OMAP_RTC_MONTHS_REG 0x10
49#define OMAP_RTC_YEARS_REG 0x14
50#define OMAP_RTC_WEEKS_REG 0x18
51
52#define OMAP_RTC_ALARM_SECONDS_REG 0x20
53#define OMAP_RTC_ALARM_MINUTES_REG 0x24
54#define OMAP_RTC_ALARM_HOURS_REG 0x28
55#define OMAP_RTC_ALARM_DAYS_REG 0x2c
56#define OMAP_RTC_ALARM_MONTHS_REG 0x30
57#define OMAP_RTC_ALARM_YEARS_REG 0x34
58
59#define OMAP_RTC_CTRL_REG 0x40
60#define OMAP_RTC_STATUS_REG 0x44
61#define OMAP_RTC_INTERRUPTS_REG 0x48
62
63#define OMAP_RTC_COMP_LSB_REG 0x4c
64#define OMAP_RTC_COMP_MSB_REG 0x50
65#define OMAP_RTC_OSC_REG 0x54
66
67/* OMAP_RTC_CTRL_REG bit fields: */
68#define OMAP_RTC_CTRL_SPLIT (1<<7)
69#define OMAP_RTC_CTRL_DISABLE (1<<6)
70#define OMAP_RTC_CTRL_SET_32_COUNTER (1<<5)
71#define OMAP_RTC_CTRL_TEST (1<<4)
72#define OMAP_RTC_CTRL_MODE_12_24 (1<<3)
73#define OMAP_RTC_CTRL_AUTO_COMP (1<<2)
74#define OMAP_RTC_CTRL_ROUND_30S (1<<1)
75#define OMAP_RTC_CTRL_STOP (1<<0)
76
77/* OMAP_RTC_STATUS_REG bit fields: */
78#define OMAP_RTC_STATUS_POWER_UP (1<<7)
79#define OMAP_RTC_STATUS_ALARM (1<<6)
80#define OMAP_RTC_STATUS_1D_EVENT (1<<5)
81#define OMAP_RTC_STATUS_1H_EVENT (1<<4)
82#define OMAP_RTC_STATUS_1M_EVENT (1<<3)
83#define OMAP_RTC_STATUS_1S_EVENT (1<<2)
84#define OMAP_RTC_STATUS_RUN (1<<1)
85#define OMAP_RTC_STATUS_BUSY (1<<0)
86
87/* OMAP_RTC_INTERRUPTS_REG bit fields: */
88#define OMAP_RTC_INTERRUPTS_IT_ALARM (1<<3)
89#define OMAP_RTC_INTERRUPTS_IT_TIMER (1<<2)
90
91
92#define rtc_read(addr) omap_readb(OMAP_RTC_BASE + (addr))
93#define rtc_write(val, addr) omap_writeb(val, OMAP_RTC_BASE + (addr))
94
95
96/* platform_bus isn't hotpluggable, so for static linkage it'd be safe
97 * to get rid of probe() and remove() code ... too bad the driver struct
98 * remembers probe(), that's about 25% of the runtime footprint!!
99 */
100#ifndef MODULE
101#undef __devexit
102#undef __devexit_p
103#define __devexit __exit
104#define __devexit_p __exit_p
105#endif
106
107
108/* we rely on the rtc framework to handle locking (rtc->ops_lock),
109 * so the only other requirement is that register accesses which
110 * require BUSY to be clear are made with IRQs locally disabled
111 */
112static void rtc_wait_not_busy(void)
113{
114 int count = 0;
115 u8 status;
116
117 /* BUSY may stay active for 1/32768 second (~30 usec) */
118 for (count = 0; count < 50; count++) {
119 status = rtc_read(OMAP_RTC_STATUS_REG);
120 if ((status & (u8)OMAP_RTC_STATUS_BUSY) == 0)
121 break;
122 udelay(1);
123 }
124 /* now we have ~15 usec to read/write various registers */
125}
126
127static irqreturn_t rtc_irq(int irq, void *class_dev)
128{
129 unsigned long events = 0;
130 u8 irq_data;
131
132 irq_data = rtc_read(OMAP_RTC_STATUS_REG);
133
134 /* alarm irq? */
135 if (irq_data & OMAP_RTC_STATUS_ALARM) {
136 rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
137 events |= RTC_IRQF | RTC_AF;
138 }
139
140 /* 1/sec periodic/update irq? */
141 if (irq_data & OMAP_RTC_STATUS_1S_EVENT)
142 events |= RTC_IRQF | RTC_UF;
143
144 rtc_update_irq(class_dev, 1, events);
145
146 return IRQ_HANDLED;
147}
148
149#ifdef CONFIG_RTC_INTF_DEV
150
151static int
152omap_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
153{
154 u8 reg;
155
156 switch (cmd) {
157 case RTC_AIE_OFF:
158 case RTC_AIE_ON:
159 case RTC_UIE_OFF:
160 case RTC_UIE_ON:
161 break;
162 default:
163 return -ENOIOCTLCMD;
164 }
165
166 local_irq_disable();
167 rtc_wait_not_busy();
168 reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
169 switch (cmd) {
170 /* AIE = Alarm Interrupt Enable */
171 case RTC_AIE_OFF:
172 reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
173 break;
174 case RTC_AIE_ON:
175 reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
176 break;
177 /* UIE = Update Interrupt Enable (1/second) */
178 case RTC_UIE_OFF:
179 reg &= ~OMAP_RTC_INTERRUPTS_IT_TIMER;
180 break;
181 case RTC_UIE_ON:
182 reg |= OMAP_RTC_INTERRUPTS_IT_TIMER;
183 break;
184 }
185 rtc_wait_not_busy();
186 rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
187 local_irq_enable();
188
189 return 0;
190}
191
192#else
193#define omap_rtc_ioctl NULL
194#endif
195
196/* this hardware doesn't support "don't care" alarm fields */
197static int tm2bcd(struct rtc_time *tm)
198{
199 if (rtc_valid_tm(tm) != 0)
200 return -EINVAL;
201
202 tm->tm_sec = BIN2BCD(tm->tm_sec);
203 tm->tm_min = BIN2BCD(tm->tm_min);
204 tm->tm_hour = BIN2BCD(tm->tm_hour);
205 tm->tm_mday = BIN2BCD(tm->tm_mday);
206
207 tm->tm_mon = BIN2BCD(tm->tm_mon + 1);
208
209 /* epoch == 1900 */
210 if (tm->tm_year < 100 || tm->tm_year > 199)
211 return -EINVAL;
212 tm->tm_year = BIN2BCD(tm->tm_year - 100);
213
214 return 0;
215}
216
217static void bcd2tm(struct rtc_time *tm)
218{
219 tm->tm_sec = BCD2BIN(tm->tm_sec);
220 tm->tm_min = BCD2BIN(tm->tm_min);
221 tm->tm_hour = BCD2BIN(tm->tm_hour);
222 tm->tm_mday = BCD2BIN(tm->tm_mday);
223 tm->tm_mon = BCD2BIN(tm->tm_mon) - 1;
224 /* epoch == 1900 */
225 tm->tm_year = BCD2BIN(tm->tm_year) + 100;
226}
227
228
229static int omap_rtc_read_time(struct device *dev, struct rtc_time *tm)
230{
231 /* we don't report wday/yday/isdst ... */
232 local_irq_disable();
233 rtc_wait_not_busy();
234
235 tm->tm_sec = rtc_read(OMAP_RTC_SECONDS_REG);
236 tm->tm_min = rtc_read(OMAP_RTC_MINUTES_REG);
237 tm->tm_hour = rtc_read(OMAP_RTC_HOURS_REG);
238 tm->tm_mday = rtc_read(OMAP_RTC_DAYS_REG);
239 tm->tm_mon = rtc_read(OMAP_RTC_MONTHS_REG);
240 tm->tm_year = rtc_read(OMAP_RTC_YEARS_REG);
241
242 local_irq_enable();
243
244 bcd2tm(tm);
245 return 0;
246}
247
248static int omap_rtc_set_time(struct device *dev, struct rtc_time *tm)
249{
250 if (tm2bcd(tm) < 0)
251 return -EINVAL;
252 local_irq_disable();
253 rtc_wait_not_busy();
254
255 rtc_write(tm->tm_year, OMAP_RTC_YEARS_REG);
256 rtc_write(tm->tm_mon, OMAP_RTC_MONTHS_REG);
257 rtc_write(tm->tm_mday, OMAP_RTC_DAYS_REG);
258 rtc_write(tm->tm_hour, OMAP_RTC_HOURS_REG);
259 rtc_write(tm->tm_min, OMAP_RTC_MINUTES_REG);
260 rtc_write(tm->tm_sec, OMAP_RTC_SECONDS_REG);
261
262 local_irq_enable();
263
264 return 0;
265}
266
267static int omap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
268{
269 local_irq_disable();
270 rtc_wait_not_busy();
271
272 alm->time.tm_sec = rtc_read(OMAP_RTC_ALARM_SECONDS_REG);
273 alm->time.tm_min = rtc_read(OMAP_RTC_ALARM_MINUTES_REG);
274 alm->time.tm_hour = rtc_read(OMAP_RTC_ALARM_HOURS_REG);
275 alm->time.tm_mday = rtc_read(OMAP_RTC_ALARM_DAYS_REG);
276 alm->time.tm_mon = rtc_read(OMAP_RTC_ALARM_MONTHS_REG);
277 alm->time.tm_year = rtc_read(OMAP_RTC_ALARM_YEARS_REG);
278
279 local_irq_enable();
280
281 bcd2tm(&alm->time);
David Brownella2db8df2006-12-13 00:35:08 -0800282 alm->enabled = !!(rtc_read(OMAP_RTC_INTERRUPTS_REG)
David Brownelldb68b182006-12-06 20:38:36 -0800283 & OMAP_RTC_INTERRUPTS_IT_ALARM);
David Brownelldb68b182006-12-06 20:38:36 -0800284
285 return 0;
286}
287
288static int omap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
289{
290 u8 reg;
291
292 /* Much userspace code uses RTC_ALM_SET, thus "don't care" for
293 * day/month/year specifies alarms up to 24 hours in the future.
294 * So we need to handle that ... but let's ignore the "don't care"
295 * values for hours/minutes/seconds.
296 */
297 if (alm->time.tm_mday <= 0
298 && alm->time.tm_mon < 0
299 && alm->time.tm_year < 0) {
300 struct rtc_time tm;
301 unsigned long now, then;
302
303 omap_rtc_read_time(dev, &tm);
304 rtc_tm_to_time(&tm, &now);
305
306 alm->time.tm_mday = tm.tm_mday;
307 alm->time.tm_mon = tm.tm_mon;
308 alm->time.tm_year = tm.tm_year;
309 rtc_tm_to_time(&alm->time, &then);
310
311 /* sometimes the alarm wraps into tomorrow */
312 if (then < now) {
313 rtc_time_to_tm(now + 24 * 60 * 60, &tm);
314 alm->time.tm_mday = tm.tm_mday;
315 alm->time.tm_mon = tm.tm_mon;
316 alm->time.tm_year = tm.tm_year;
317 }
318 }
319
320 if (tm2bcd(&alm->time) < 0)
321 return -EINVAL;
322
323 local_irq_disable();
324 rtc_wait_not_busy();
325
326 rtc_write(alm->time.tm_year, OMAP_RTC_ALARM_YEARS_REG);
327 rtc_write(alm->time.tm_mon, OMAP_RTC_ALARM_MONTHS_REG);
328 rtc_write(alm->time.tm_mday, OMAP_RTC_ALARM_DAYS_REG);
329 rtc_write(alm->time.tm_hour, OMAP_RTC_ALARM_HOURS_REG);
330 rtc_write(alm->time.tm_min, OMAP_RTC_ALARM_MINUTES_REG);
331 rtc_write(alm->time.tm_sec, OMAP_RTC_ALARM_SECONDS_REG);
332
333 reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
334 if (alm->enabled)
335 reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
336 else
337 reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
338 rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
339
340 local_irq_enable();
341
342 return 0;
343}
344
345static struct rtc_class_ops omap_rtc_ops = {
346 .ioctl = omap_rtc_ioctl,
347 .read_time = omap_rtc_read_time,
348 .set_time = omap_rtc_set_time,
349 .read_alarm = omap_rtc_read_alarm,
350 .set_alarm = omap_rtc_set_alarm,
351};
352
353static int omap_rtc_alarm;
354static int omap_rtc_timer;
355
356static int __devinit omap_rtc_probe(struct platform_device *pdev)
357{
358 struct resource *res, *mem;
359 struct rtc_device *rtc;
360 u8 reg, new_ctrl;
361
362 omap_rtc_timer = platform_get_irq(pdev, 0);
363 if (omap_rtc_timer <= 0) {
364 pr_debug("%s: no update irq?\n", pdev->name);
365 return -ENOENT;
366 }
367
368 omap_rtc_alarm = platform_get_irq(pdev, 1);
369 if (omap_rtc_alarm <= 0) {
370 pr_debug("%s: no alarm irq?\n", pdev->name);
371 return -ENOENT;
372 }
373
374 /* NOTE: using static mapping for RTC registers */
375 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
376 if (res && res->start != OMAP_RTC_BASE) {
377 pr_debug("%s: RTC registers at %08x, expected %08x\n",
378 pdev->name, (unsigned) res->start, OMAP_RTC_BASE);
379 return -ENOENT;
380 }
381
382 if (res)
383 mem = request_mem_region(res->start,
384 res->end - res->start + 1,
385 pdev->name);
386 else
387 mem = NULL;
388 if (!mem) {
389 pr_debug("%s: RTC registers at %08x are not free\n",
390 pdev->name, OMAP_RTC_BASE);
391 return -EBUSY;
392 }
393
394 rtc = rtc_device_register(pdev->name, &pdev->dev,
395 &omap_rtc_ops, THIS_MODULE);
396 if (IS_ERR(rtc)) {
397 pr_debug("%s: can't register RTC device, err %ld\n",
398 pdev->name, PTR_ERR(rtc));
399 goto fail;
400 }
401 platform_set_drvdata(pdev, rtc);
402 class_set_devdata(&rtc->class_dev, mem);
403
404 /* clear pending irqs, and set 1/second periodic,
405 * which we'll use instead of update irqs
406 */
407 rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
408
409 /* clear old status */
410 reg = rtc_read(OMAP_RTC_STATUS_REG);
411 if (reg & (u8) OMAP_RTC_STATUS_POWER_UP) {
412 pr_info("%s: RTC power up reset detected\n",
413 pdev->name);
414 rtc_write(OMAP_RTC_STATUS_POWER_UP, OMAP_RTC_STATUS_REG);
415 }
416 if (reg & (u8) OMAP_RTC_STATUS_ALARM)
417 rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
418
419 /* handle periodic and alarm irqs */
Thomas Gleixner38515e92007-02-14 00:33:16 -0800420 if (request_irq(omap_rtc_timer, rtc_irq, IRQF_DISABLED,
David Brownelldb68b182006-12-06 20:38:36 -0800421 rtc->class_dev.class_id, &rtc->class_dev)) {
422 pr_debug("%s: RTC timer interrupt IRQ%d already claimed\n",
423 pdev->name, omap_rtc_timer);
424 goto fail0;
425 }
Thomas Gleixner38515e92007-02-14 00:33:16 -0800426 if (request_irq(omap_rtc_alarm, rtc_irq, IRQF_DISABLED,
David Brownelldb68b182006-12-06 20:38:36 -0800427 rtc->class_dev.class_id, &rtc->class_dev)) {
428 pr_debug("%s: RTC alarm interrupt IRQ%d already claimed\n",
429 pdev->name, omap_rtc_alarm);
430 goto fail1;
431 }
432
433 /* On boards with split power, RTC_ON_NOFF won't reset the RTC */
434 reg = rtc_read(OMAP_RTC_CTRL_REG);
435 if (reg & (u8) OMAP_RTC_CTRL_STOP)
436 pr_info("%s: already running\n", pdev->name);
437
438 /* force to 24 hour mode */
439 new_ctrl = reg & ~(OMAP_RTC_CTRL_SPLIT|OMAP_RTC_CTRL_AUTO_COMP);
440 new_ctrl |= OMAP_RTC_CTRL_STOP;
441
442 /* BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE:
443 *
444 * - Boards wired so that RTC_WAKE_INT does something, and muxed
445 * right (W13_1610_RTC_WAKE_INT is the default after chip reset),
446 * should initialize the device wakeup flag appropriately.
447 *
448 * - Boards wired so RTC_ON_nOFF is used as the reset signal,
449 * rather than nPWRON_RESET, should forcibly enable split
450 * power mode. (Some chip errata report that RTC_CTRL_SPLIT
451 * is write-only, and always reads as zero...)
452 */
453 device_init_wakeup(&pdev->dev, 0);
454
455 if (new_ctrl & (u8) OMAP_RTC_CTRL_SPLIT)
456 pr_info("%s: split power mode\n", pdev->name);
457
458 if (reg != new_ctrl)
459 rtc_write(new_ctrl, OMAP_RTC_CTRL_REG);
460
461 return 0;
462
463fail1:
464 free_irq(omap_rtc_timer, NULL);
465fail0:
466 rtc_device_unregister(rtc);
467fail:
468 release_resource(mem);
469 return -EIO;
470}
471
472static int __devexit omap_rtc_remove(struct platform_device *pdev)
473{
474 struct rtc_device *rtc = platform_get_drvdata(pdev);;
475
476 device_init_wakeup(&pdev->dev, 0);
477
478 /* leave rtc running, but disable irqs */
479 rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
480
481 free_irq(omap_rtc_timer, rtc);
482 free_irq(omap_rtc_alarm, rtc);
483
484 release_resource(class_get_devdata(&rtc->class_dev));
485 rtc_device_unregister(rtc);
486 return 0;
487}
488
489#ifdef CONFIG_PM
490
491static struct timespec rtc_delta;
492static u8 irqstat;
493
494static int omap_rtc_suspend(struct platform_device *pdev, pm_message_t state)
495{
496 struct rtc_time rtc_tm;
497 struct timespec time;
498
499 time.tv_nsec = 0;
500 omap_rtc_read_time(NULL, &rtc_tm);
501 rtc_tm_to_time(&rtc_tm, &time.tv_sec);
502
503 save_time_delta(&rtc_delta, &time);
504 irqstat = rtc_read(OMAP_RTC_INTERRUPTS_REG);
505
506 /* FIXME the RTC alarm is not currently acting as a wakeup event
507 * source, and in fact this enable() call is just saving a flag
508 * that's never used...
509 */
510 if (device_may_wakeup(&pdev->dev))
511 enable_irq_wake(omap_rtc_alarm);
512 else
513 rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
514
515 return 0;
516}
517
518static int omap_rtc_resume(struct platform_device *pdev)
519{
520 struct rtc_time rtc_tm;
521 struct timespec time;
522
523 time.tv_nsec = 0;
524 omap_rtc_read_time(NULL, &rtc_tm);
525 rtc_tm_to_time(&rtc_tm, &time.tv_sec);
526
527 restore_time_delta(&rtc_delta, &time);
528 if (device_may_wakeup(&pdev->dev))
529 disable_irq_wake(omap_rtc_alarm);
530 else
531 rtc_write(irqstat, OMAP_RTC_INTERRUPTS_REG);
532 return 0;
533}
534
535#else
536#define omap_rtc_suspend NULL
537#define omap_rtc_resume NULL
538#endif
539
540static void omap_rtc_shutdown(struct platform_device *pdev)
541{
542 rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
543}
544
545MODULE_ALIAS("omap_rtc");
546static struct platform_driver omap_rtc_driver = {
547 .probe = omap_rtc_probe,
548 .remove = __devexit_p(omap_rtc_remove),
549 .suspend = omap_rtc_suspend,
550 .resume = omap_rtc_resume,
551 .shutdown = omap_rtc_shutdown,
552 .driver = {
553 .name = "omap_rtc",
554 .owner = THIS_MODULE,
555 },
556};
557
558static int __init rtc_init(void)
559{
560 return platform_driver_register(&omap_rtc_driver);
561}
562module_init(rtc_init);
563
564static void __exit rtc_exit(void)
565{
566 platform_driver_unregister(&omap_rtc_driver);
567}
568module_exit(rtc_exit);
569
570MODULE_AUTHOR("George G. Davis (and others)");
571MODULE_LICENSE("GPL");