Linux 2.6.20.7
[linux/fpc-iii.git] / drivers / rtc / rtc-omap.c
blobd59880d44fba26e3555c46d000c13a65e12d3ec4
1 /*
2 * TI OMAP1 Real Time Clock interface for Linux
4 * Copyright (C) 2003 MontaVista Software, Inc.
5 * Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com>
7 * Copyright (C) 2006 David Brownell (new RTC framework)
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.
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>
24 #include <asm/io.h>
25 #include <asm/mach/time.h>
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.
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.
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.
41 #define OMAP_RTC_BASE 0xfffb4800
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
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
59 #define OMAP_RTC_CTRL_REG 0x40
60 #define OMAP_RTC_STATUS_REG 0x44
61 #define OMAP_RTC_INTERRUPTS_REG 0x48
63 #define OMAP_RTC_COMP_LSB_REG 0x4c
64 #define OMAP_RTC_COMP_MSB_REG 0x50
65 #define OMAP_RTC_OSC_REG 0x54
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)
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)
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)
92 #define rtc_read(addr) omap_readb(OMAP_RTC_BASE + (addr))
93 #define rtc_write(val, addr) omap_writeb(val, OMAP_RTC_BASE + (addr))
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!!
100 #ifndef MODULE
101 #undef __devexit
102 #undef __devexit_p
103 #define __devexit __exit
104 #define __devexit_p __exit_p
105 #endif
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
112 static void rtc_wait_not_busy(void)
114 int count = 0;
115 u8 status;
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);
124 /* now we have ~15 usec to read/write various registers */
127 static irqreturn_t rtc_irq(int irq, void *class_dev)
129 unsigned long events = 0;
130 u8 irq_data;
132 irq_data = rtc_read(OMAP_RTC_STATUS_REG);
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;
140 /* 1/sec periodic/update irq? */
141 if (irq_data & OMAP_RTC_STATUS_1S_EVENT)
142 events |= RTC_IRQF | RTC_UF;
144 rtc_update_irq(class_dev, 1, events);
146 return IRQ_HANDLED;
149 #ifdef CONFIG_RTC_INTF_DEV
151 static int
152 omap_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
154 u8 reg;
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;
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;
185 rtc_wait_not_busy();
186 rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
187 local_irq_enable();
189 return 0;
192 #else
193 #define omap_rtc_ioctl NULL
194 #endif
196 /* this hardware doesn't support "don't care" alarm fields */
197 static int tm2bcd(struct rtc_time *tm)
199 if (rtc_valid_tm(tm) != 0)
200 return -EINVAL;
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);
207 tm->tm_mon = BIN2BCD(tm->tm_mon + 1);
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);
214 return 0;
217 static void bcd2tm(struct rtc_time *tm)
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;
229 static int omap_rtc_read_time(struct device *dev, struct rtc_time *tm)
231 /* we don't report wday/yday/isdst ... */
232 local_irq_disable();
233 rtc_wait_not_busy();
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);
242 local_irq_enable();
244 bcd2tm(tm);
245 return 0;
248 static int omap_rtc_set_time(struct device *dev, struct rtc_time *tm)
250 if (tm2bcd(tm) < 0)
251 return -EINVAL;
252 local_irq_disable();
253 rtc_wait_not_busy();
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);
262 local_irq_enable();
264 return 0;
267 static int omap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
269 local_irq_disable();
270 rtc_wait_not_busy();
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);
279 local_irq_enable();
281 bcd2tm(&alm->time);
282 alm->enabled = !!(rtc_read(OMAP_RTC_INTERRUPTS_REG)
283 & OMAP_RTC_INTERRUPTS_IT_ALARM);
285 return 0;
288 static int omap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
290 u8 reg;
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.
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;
303 omap_rtc_read_time(dev, &tm);
304 rtc_tm_to_time(&tm, &now);
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);
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;
320 if (tm2bcd(&alm->time) < 0)
321 return -EINVAL;
323 local_irq_disable();
324 rtc_wait_not_busy();
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);
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);
340 local_irq_enable();
342 return 0;
345 static 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,
353 static int omap_rtc_alarm;
354 static int omap_rtc_timer;
356 static int __devinit omap_rtc_probe(struct platform_device *pdev)
358 struct resource *res, *mem;
359 struct rtc_device *rtc;
360 u8 reg, new_ctrl;
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;
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;
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;
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;
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;
401 platform_set_drvdata(pdev, rtc);
402 class_set_devdata(&rtc->class_dev, mem);
404 /* clear pending irqs, and set 1/second periodic,
405 * which we'll use instead of update irqs
407 rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
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);
416 if (reg & (u8) OMAP_RTC_STATUS_ALARM)
417 rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
419 /* handle periodic and alarm irqs */
420 if (request_irq(omap_rtc_timer, rtc_irq, SA_INTERRUPT,
421 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;
426 if (request_irq(omap_rtc_alarm, rtc_irq, SA_INTERRUPT,
427 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;
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);
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;
442 /* BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE:
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.
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...)
453 device_init_wakeup(&pdev->dev, 0);
455 if (new_ctrl & (u8) OMAP_RTC_CTRL_SPLIT)
456 pr_info("%s: split power mode\n", pdev->name);
458 if (reg != new_ctrl)
459 rtc_write(new_ctrl, OMAP_RTC_CTRL_REG);
461 return 0;
463 fail1:
464 free_irq(omap_rtc_timer, NULL);
465 fail0:
466 rtc_device_unregister(rtc);
467 fail:
468 release_resource(mem);
469 return -EIO;
472 static int __devexit omap_rtc_remove(struct platform_device *pdev)
474 struct rtc_device *rtc = platform_get_drvdata(pdev);;
476 device_init_wakeup(&pdev->dev, 0);
478 /* leave rtc running, but disable irqs */
479 rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
481 free_irq(omap_rtc_timer, rtc);
482 free_irq(omap_rtc_alarm, rtc);
484 release_resource(class_get_devdata(&rtc->class_dev));
485 rtc_device_unregister(rtc);
486 return 0;
489 #ifdef CONFIG_PM
491 static struct timespec rtc_delta;
492 static u8 irqstat;
494 static int omap_rtc_suspend(struct platform_device *pdev, pm_message_t state)
496 struct rtc_time rtc_tm;
497 struct timespec time;
499 time.tv_nsec = 0;
500 omap_rtc_read_time(NULL, &rtc_tm);
501 rtc_tm_to_time(&rtc_tm, &time.tv_sec);
503 save_time_delta(&rtc_delta, &time);
504 irqstat = rtc_read(OMAP_RTC_INTERRUPTS_REG);
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...
510 if (device_may_wakeup(&pdev->dev))
511 enable_irq_wake(omap_rtc_alarm);
512 else
513 rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
515 return 0;
518 static int omap_rtc_resume(struct platform_device *pdev)
520 struct rtc_time rtc_tm;
521 struct timespec time;
523 time.tv_nsec = 0;
524 omap_rtc_read_time(NULL, &rtc_tm);
525 rtc_tm_to_time(&rtc_tm, &time.tv_sec);
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;
535 #else
536 #define omap_rtc_suspend NULL
537 #define omap_rtc_resume NULL
538 #endif
540 static void omap_rtc_shutdown(struct platform_device *pdev)
542 rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
545 MODULE_ALIAS("omap_rtc");
546 static 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,
558 static int __init rtc_init(void)
560 return platform_driver_register(&omap_rtc_driver);
562 module_init(rtc_init);
564 static void __exit rtc_exit(void)
566 platform_driver_unregister(&omap_rtc_driver);
568 module_exit(rtc_exit);
570 MODULE_AUTHOR("George G. Davis (and others)");
571 MODULE_LICENSE("GPL");