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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
David Brownellab6a2d72007-05-08 00:33:30 -0700127static irqreturn_t rtc_irq(int irq, void *rtc)
David Brownelldb68b182006-12-06 20:38:36 -0800128{
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
David Brownellab6a2d72007-05-08 00:33:30 -0700144 rtc_update_irq(rtc, 1, events);
David Brownelldb68b182006-12-06 20:38:36 -0800145
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
David Brownelldb68b182006-12-06 20:38:36 -0800292 if (tm2bcd(&alm->time) < 0)
293 return -EINVAL;
294
295 local_irq_disable();
296 rtc_wait_not_busy();
297
298 rtc_write(alm->time.tm_year, OMAP_RTC_ALARM_YEARS_REG);
299 rtc_write(alm->time.tm_mon, OMAP_RTC_ALARM_MONTHS_REG);
300 rtc_write(alm->time.tm_mday, OMAP_RTC_ALARM_DAYS_REG);
301 rtc_write(alm->time.tm_hour, OMAP_RTC_ALARM_HOURS_REG);
302 rtc_write(alm->time.tm_min, OMAP_RTC_ALARM_MINUTES_REG);
303 rtc_write(alm->time.tm_sec, OMAP_RTC_ALARM_SECONDS_REG);
304
305 reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
306 if (alm->enabled)
307 reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
308 else
309 reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
310 rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
311
312 local_irq_enable();
313
314 return 0;
315}
316
317static struct rtc_class_ops omap_rtc_ops = {
318 .ioctl = omap_rtc_ioctl,
319 .read_time = omap_rtc_read_time,
320 .set_time = omap_rtc_set_time,
321 .read_alarm = omap_rtc_read_alarm,
322 .set_alarm = omap_rtc_set_alarm,
323};
324
325static int omap_rtc_alarm;
326static int omap_rtc_timer;
327
328static int __devinit omap_rtc_probe(struct platform_device *pdev)
329{
330 struct resource *res, *mem;
331 struct rtc_device *rtc;
332 u8 reg, new_ctrl;
333
334 omap_rtc_timer = platform_get_irq(pdev, 0);
335 if (omap_rtc_timer <= 0) {
336 pr_debug("%s: no update irq?\n", pdev->name);
337 return -ENOENT;
338 }
339
340 omap_rtc_alarm = platform_get_irq(pdev, 1);
341 if (omap_rtc_alarm <= 0) {
342 pr_debug("%s: no alarm irq?\n", pdev->name);
343 return -ENOENT;
344 }
345
346 /* NOTE: using static mapping for RTC registers */
347 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
348 if (res && res->start != OMAP_RTC_BASE) {
349 pr_debug("%s: RTC registers at %08x, expected %08x\n",
350 pdev->name, (unsigned) res->start, OMAP_RTC_BASE);
351 return -ENOENT;
352 }
353
354 if (res)
355 mem = request_mem_region(res->start,
356 res->end - res->start + 1,
357 pdev->name);
358 else
359 mem = NULL;
360 if (!mem) {
361 pr_debug("%s: RTC registers at %08x are not free\n",
362 pdev->name, OMAP_RTC_BASE);
363 return -EBUSY;
364 }
365
366 rtc = rtc_device_register(pdev->name, &pdev->dev,
367 &omap_rtc_ops, THIS_MODULE);
368 if (IS_ERR(rtc)) {
369 pr_debug("%s: can't register RTC device, err %ld\n",
370 pdev->name, PTR_ERR(rtc));
371 goto fail;
372 }
373 platform_set_drvdata(pdev, rtc);
David Brownell558a40f2007-05-16 22:11:14 -0700374 dev_set_drvdata(&rtc->dev, mem);
David Brownelldb68b182006-12-06 20:38:36 -0800375
376 /* clear pending irqs, and set 1/second periodic,
377 * which we'll use instead of update irqs
378 */
379 rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
380
381 /* clear old status */
382 reg = rtc_read(OMAP_RTC_STATUS_REG);
383 if (reg & (u8) OMAP_RTC_STATUS_POWER_UP) {
384 pr_info("%s: RTC power up reset detected\n",
385 pdev->name);
386 rtc_write(OMAP_RTC_STATUS_POWER_UP, OMAP_RTC_STATUS_REG);
387 }
388 if (reg & (u8) OMAP_RTC_STATUS_ALARM)
389 rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
390
391 /* handle periodic and alarm irqs */
Thomas Gleixner38515e92007-02-14 00:33:16 -0800392 if (request_irq(omap_rtc_timer, rtc_irq, IRQF_DISABLED,
David Brownellcd966202007-05-08 00:33:40 -0700393 rtc->dev.bus_id, rtc)) {
David Brownelldb68b182006-12-06 20:38:36 -0800394 pr_debug("%s: RTC timer interrupt IRQ%d already claimed\n",
395 pdev->name, omap_rtc_timer);
396 goto fail0;
397 }
Thomas Gleixner38515e92007-02-14 00:33:16 -0800398 if (request_irq(omap_rtc_alarm, rtc_irq, IRQF_DISABLED,
David Brownellcd966202007-05-08 00:33:40 -0700399 rtc->dev.bus_id, rtc)) {
David Brownelldb68b182006-12-06 20:38:36 -0800400 pr_debug("%s: RTC alarm interrupt IRQ%d already claimed\n",
401 pdev->name, omap_rtc_alarm);
402 goto fail1;
403 }
404
405 /* On boards with split power, RTC_ON_NOFF won't reset the RTC */
406 reg = rtc_read(OMAP_RTC_CTRL_REG);
407 if (reg & (u8) OMAP_RTC_CTRL_STOP)
408 pr_info("%s: already running\n", pdev->name);
409
410 /* force to 24 hour mode */
411 new_ctrl = reg & ~(OMAP_RTC_CTRL_SPLIT|OMAP_RTC_CTRL_AUTO_COMP);
412 new_ctrl |= OMAP_RTC_CTRL_STOP;
413
414 /* BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE:
415 *
416 * - Boards wired so that RTC_WAKE_INT does something, and muxed
417 * right (W13_1610_RTC_WAKE_INT is the default after chip reset),
418 * should initialize the device wakeup flag appropriately.
419 *
420 * - Boards wired so RTC_ON_nOFF is used as the reset signal,
421 * rather than nPWRON_RESET, should forcibly enable split
422 * power mode. (Some chip errata report that RTC_CTRL_SPLIT
423 * is write-only, and always reads as zero...)
424 */
425 device_init_wakeup(&pdev->dev, 0);
426
427 if (new_ctrl & (u8) OMAP_RTC_CTRL_SPLIT)
428 pr_info("%s: split power mode\n", pdev->name);
429
430 if (reg != new_ctrl)
431 rtc_write(new_ctrl, OMAP_RTC_CTRL_REG);
432
433 return 0;
434
435fail1:
436 free_irq(omap_rtc_timer, NULL);
437fail0:
438 rtc_device_unregister(rtc);
439fail:
440 release_resource(mem);
441 return -EIO;
442}
443
444static int __devexit omap_rtc_remove(struct platform_device *pdev)
445{
446 struct rtc_device *rtc = platform_get_drvdata(pdev);;
447
448 device_init_wakeup(&pdev->dev, 0);
449
450 /* leave rtc running, but disable irqs */
451 rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
452
453 free_irq(omap_rtc_timer, rtc);
454 free_irq(omap_rtc_alarm, rtc);
455
David Brownell558a40f2007-05-16 22:11:14 -0700456 release_resource(dev_get_drvdata(&rtc->dev));
David Brownelldb68b182006-12-06 20:38:36 -0800457 rtc_device_unregister(rtc);
458 return 0;
459}
460
461#ifdef CONFIG_PM
462
David Brownelldb68b182006-12-06 20:38:36 -0800463static u8 irqstat;
464
465static int omap_rtc_suspend(struct platform_device *pdev, pm_message_t state)
466{
David Brownelldb68b182006-12-06 20:38:36 -0800467 irqstat = rtc_read(OMAP_RTC_INTERRUPTS_REG);
468
469 /* FIXME the RTC alarm is not currently acting as a wakeup event
470 * source, and in fact this enable() call is just saving a flag
471 * that's never used...
472 */
473 if (device_may_wakeup(&pdev->dev))
474 enable_irq_wake(omap_rtc_alarm);
475 else
476 rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
477
478 return 0;
479}
480
481static int omap_rtc_resume(struct platform_device *pdev)
482{
David Brownelldb68b182006-12-06 20:38:36 -0800483 if (device_may_wakeup(&pdev->dev))
484 disable_irq_wake(omap_rtc_alarm);
485 else
486 rtc_write(irqstat, OMAP_RTC_INTERRUPTS_REG);
487 return 0;
488}
489
490#else
491#define omap_rtc_suspend NULL
492#define omap_rtc_resume NULL
493#endif
494
495static void omap_rtc_shutdown(struct platform_device *pdev)
496{
497 rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
498}
499
500MODULE_ALIAS("omap_rtc");
501static struct platform_driver omap_rtc_driver = {
502 .probe = omap_rtc_probe,
503 .remove = __devexit_p(omap_rtc_remove),
504 .suspend = omap_rtc_suspend,
505 .resume = omap_rtc_resume,
506 .shutdown = omap_rtc_shutdown,
507 .driver = {
508 .name = "omap_rtc",
509 .owner = THIS_MODULE,
510 },
511};
512
513static int __init rtc_init(void)
514{
515 return platform_driver_register(&omap_rtc_driver);
516}
517module_init(rtc_init);
518
519static void __exit rtc_exit(void)
520{
521 platform_driver_unregister(&omap_rtc_driver);
522}
523module_exit(rtc_exit);
524
525MODULE_AUTHOR("George G. Davis (and others)");
526MODULE_LICENSE("GPL");