blob: bd1ce8e2bc1866d8a6fbeff8318b5ac7d105675a [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>
David Brownelldb68b182006-12-06 20:38:36 -080025
26
27/* The OMAP1 RTC is a year/month/day/hours/minutes/seconds BCD clock
28 * with century-range alarm matching, driven by the 32kHz clock.
29 *
30 * The main user-visible ways it differs from PC RTCs are by omitting
31 * "don't care" alarm fields and sub-second periodic IRQs, and having
32 * an autoadjust mechanism to calibrate to the true oscillator rate.
33 *
34 * Board-specific wiring options include using split power mode with
35 * RTC_OFF_NOFF used as the reset signal (so the RTC won't be reset),
36 * and wiring RTC_WAKE_INT (so the RTC alarm can wake the system from
37 * low power modes). See the BOARD-SPECIFIC CUSTOMIZATION comment.
38 */
39
40#define OMAP_RTC_BASE 0xfffb4800
41
42/* RTC registers */
43#define OMAP_RTC_SECONDS_REG 0x00
44#define OMAP_RTC_MINUTES_REG 0x04
45#define OMAP_RTC_HOURS_REG 0x08
46#define OMAP_RTC_DAYS_REG 0x0C
47#define OMAP_RTC_MONTHS_REG 0x10
48#define OMAP_RTC_YEARS_REG 0x14
49#define OMAP_RTC_WEEKS_REG 0x18
50
51#define OMAP_RTC_ALARM_SECONDS_REG 0x20
52#define OMAP_RTC_ALARM_MINUTES_REG 0x24
53#define OMAP_RTC_ALARM_HOURS_REG 0x28
54#define OMAP_RTC_ALARM_DAYS_REG 0x2c
55#define OMAP_RTC_ALARM_MONTHS_REG 0x30
56#define OMAP_RTC_ALARM_YEARS_REG 0x34
57
58#define OMAP_RTC_CTRL_REG 0x40
59#define OMAP_RTC_STATUS_REG 0x44
60#define OMAP_RTC_INTERRUPTS_REG 0x48
61
62#define OMAP_RTC_COMP_LSB_REG 0x4c
63#define OMAP_RTC_COMP_MSB_REG 0x50
64#define OMAP_RTC_OSC_REG 0x54
65
66/* OMAP_RTC_CTRL_REG bit fields: */
67#define OMAP_RTC_CTRL_SPLIT (1<<7)
68#define OMAP_RTC_CTRL_DISABLE (1<<6)
69#define OMAP_RTC_CTRL_SET_32_COUNTER (1<<5)
70#define OMAP_RTC_CTRL_TEST (1<<4)
71#define OMAP_RTC_CTRL_MODE_12_24 (1<<3)
72#define OMAP_RTC_CTRL_AUTO_COMP (1<<2)
73#define OMAP_RTC_CTRL_ROUND_30S (1<<1)
74#define OMAP_RTC_CTRL_STOP (1<<0)
75
76/* OMAP_RTC_STATUS_REG bit fields: */
77#define OMAP_RTC_STATUS_POWER_UP (1<<7)
78#define OMAP_RTC_STATUS_ALARM (1<<6)
79#define OMAP_RTC_STATUS_1D_EVENT (1<<5)
80#define OMAP_RTC_STATUS_1H_EVENT (1<<4)
81#define OMAP_RTC_STATUS_1M_EVENT (1<<3)
82#define OMAP_RTC_STATUS_1S_EVENT (1<<2)
83#define OMAP_RTC_STATUS_RUN (1<<1)
84#define OMAP_RTC_STATUS_BUSY (1<<0)
85
86/* OMAP_RTC_INTERRUPTS_REG bit fields: */
87#define OMAP_RTC_INTERRUPTS_IT_ALARM (1<<3)
88#define OMAP_RTC_INTERRUPTS_IT_TIMER (1<<2)
89
90
91#define rtc_read(addr) omap_readb(OMAP_RTC_BASE + (addr))
92#define rtc_write(val, addr) omap_writeb(val, OMAP_RTC_BASE + (addr))
93
94
David Brownelldb68b182006-12-06 20:38:36 -080095/* we rely on the rtc framework to handle locking (rtc->ops_lock),
96 * so the only other requirement is that register accesses which
97 * require BUSY to be clear are made with IRQs locally disabled
98 */
99static void rtc_wait_not_busy(void)
100{
101 int count = 0;
102 u8 status;
103
104 /* BUSY may stay active for 1/32768 second (~30 usec) */
105 for (count = 0; count < 50; count++) {
106 status = rtc_read(OMAP_RTC_STATUS_REG);
107 if ((status & (u8)OMAP_RTC_STATUS_BUSY) == 0)
108 break;
109 udelay(1);
110 }
111 /* now we have ~15 usec to read/write various registers */
112}
113
David Brownellab6a2d72007-05-08 00:33:30 -0700114static irqreturn_t rtc_irq(int irq, void *rtc)
David Brownelldb68b182006-12-06 20:38:36 -0800115{
116 unsigned long events = 0;
117 u8 irq_data;
118
119 irq_data = rtc_read(OMAP_RTC_STATUS_REG);
120
121 /* alarm irq? */
122 if (irq_data & OMAP_RTC_STATUS_ALARM) {
123 rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
124 events |= RTC_IRQF | RTC_AF;
125 }
126
127 /* 1/sec periodic/update irq? */
128 if (irq_data & OMAP_RTC_STATUS_1S_EVENT)
129 events |= RTC_IRQF | RTC_UF;
130
David Brownellab6a2d72007-05-08 00:33:30 -0700131 rtc_update_irq(rtc, 1, events);
David Brownelldb68b182006-12-06 20:38:36 -0800132
133 return IRQ_HANDLED;
134}
135
136#ifdef CONFIG_RTC_INTF_DEV
137
138static int
139omap_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
140{
141 u8 reg;
142
143 switch (cmd) {
144 case RTC_AIE_OFF:
145 case RTC_AIE_ON:
146 case RTC_UIE_OFF:
147 case RTC_UIE_ON:
148 break;
149 default:
150 return -ENOIOCTLCMD;
151 }
152
153 local_irq_disable();
154 rtc_wait_not_busy();
155 reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
156 switch (cmd) {
157 /* AIE = Alarm Interrupt Enable */
158 case RTC_AIE_OFF:
159 reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
160 break;
161 case RTC_AIE_ON:
162 reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
163 break;
164 /* UIE = Update Interrupt Enable (1/second) */
165 case RTC_UIE_OFF:
166 reg &= ~OMAP_RTC_INTERRUPTS_IT_TIMER;
167 break;
168 case RTC_UIE_ON:
169 reg |= OMAP_RTC_INTERRUPTS_IT_TIMER;
170 break;
171 }
172 rtc_wait_not_busy();
173 rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
174 local_irq_enable();
175
176 return 0;
177}
178
179#else
180#define omap_rtc_ioctl NULL
181#endif
182
183/* this hardware doesn't support "don't care" alarm fields */
184static int tm2bcd(struct rtc_time *tm)
185{
186 if (rtc_valid_tm(tm) != 0)
187 return -EINVAL;
188
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700189 tm->tm_sec = bin2bcd(tm->tm_sec);
190 tm->tm_min = bin2bcd(tm->tm_min);
191 tm->tm_hour = bin2bcd(tm->tm_hour);
192 tm->tm_mday = bin2bcd(tm->tm_mday);
David Brownelldb68b182006-12-06 20:38:36 -0800193
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700194 tm->tm_mon = bin2bcd(tm->tm_mon + 1);
David Brownelldb68b182006-12-06 20:38:36 -0800195
196 /* epoch == 1900 */
197 if (tm->tm_year < 100 || tm->tm_year > 199)
198 return -EINVAL;
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700199 tm->tm_year = bin2bcd(tm->tm_year - 100);
David Brownelldb68b182006-12-06 20:38:36 -0800200
201 return 0;
202}
203
204static void bcd2tm(struct rtc_time *tm)
205{
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700206 tm->tm_sec = bcd2bin(tm->tm_sec);
207 tm->tm_min = bcd2bin(tm->tm_min);
208 tm->tm_hour = bcd2bin(tm->tm_hour);
209 tm->tm_mday = bcd2bin(tm->tm_mday);
210 tm->tm_mon = bcd2bin(tm->tm_mon) - 1;
David Brownelldb68b182006-12-06 20:38:36 -0800211 /* epoch == 1900 */
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700212 tm->tm_year = bcd2bin(tm->tm_year) + 100;
David Brownelldb68b182006-12-06 20:38:36 -0800213}
214
215
216static int omap_rtc_read_time(struct device *dev, struct rtc_time *tm)
217{
218 /* we don't report wday/yday/isdst ... */
219 local_irq_disable();
220 rtc_wait_not_busy();
221
222 tm->tm_sec = rtc_read(OMAP_RTC_SECONDS_REG);
223 tm->tm_min = rtc_read(OMAP_RTC_MINUTES_REG);
224 tm->tm_hour = rtc_read(OMAP_RTC_HOURS_REG);
225 tm->tm_mday = rtc_read(OMAP_RTC_DAYS_REG);
226 tm->tm_mon = rtc_read(OMAP_RTC_MONTHS_REG);
227 tm->tm_year = rtc_read(OMAP_RTC_YEARS_REG);
228
229 local_irq_enable();
230
231 bcd2tm(tm);
232 return 0;
233}
234
235static int omap_rtc_set_time(struct device *dev, struct rtc_time *tm)
236{
237 if (tm2bcd(tm) < 0)
238 return -EINVAL;
239 local_irq_disable();
240 rtc_wait_not_busy();
241
242 rtc_write(tm->tm_year, OMAP_RTC_YEARS_REG);
243 rtc_write(tm->tm_mon, OMAP_RTC_MONTHS_REG);
244 rtc_write(tm->tm_mday, OMAP_RTC_DAYS_REG);
245 rtc_write(tm->tm_hour, OMAP_RTC_HOURS_REG);
246 rtc_write(tm->tm_min, OMAP_RTC_MINUTES_REG);
247 rtc_write(tm->tm_sec, OMAP_RTC_SECONDS_REG);
248
249 local_irq_enable();
250
251 return 0;
252}
253
254static int omap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
255{
256 local_irq_disable();
257 rtc_wait_not_busy();
258
259 alm->time.tm_sec = rtc_read(OMAP_RTC_ALARM_SECONDS_REG);
260 alm->time.tm_min = rtc_read(OMAP_RTC_ALARM_MINUTES_REG);
261 alm->time.tm_hour = rtc_read(OMAP_RTC_ALARM_HOURS_REG);
262 alm->time.tm_mday = rtc_read(OMAP_RTC_ALARM_DAYS_REG);
263 alm->time.tm_mon = rtc_read(OMAP_RTC_ALARM_MONTHS_REG);
264 alm->time.tm_year = rtc_read(OMAP_RTC_ALARM_YEARS_REG);
265
266 local_irq_enable();
267
268 bcd2tm(&alm->time);
David Brownella2db8df2006-12-13 00:35:08 -0800269 alm->enabled = !!(rtc_read(OMAP_RTC_INTERRUPTS_REG)
David Brownelldb68b182006-12-06 20:38:36 -0800270 & OMAP_RTC_INTERRUPTS_IT_ALARM);
David Brownelldb68b182006-12-06 20:38:36 -0800271
272 return 0;
273}
274
275static int omap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
276{
277 u8 reg;
278
David Brownelldb68b182006-12-06 20:38:36 -0800279 if (tm2bcd(&alm->time) < 0)
280 return -EINVAL;
281
282 local_irq_disable();
283 rtc_wait_not_busy();
284
285 rtc_write(alm->time.tm_year, OMAP_RTC_ALARM_YEARS_REG);
286 rtc_write(alm->time.tm_mon, OMAP_RTC_ALARM_MONTHS_REG);
287 rtc_write(alm->time.tm_mday, OMAP_RTC_ALARM_DAYS_REG);
288 rtc_write(alm->time.tm_hour, OMAP_RTC_ALARM_HOURS_REG);
289 rtc_write(alm->time.tm_min, OMAP_RTC_ALARM_MINUTES_REG);
290 rtc_write(alm->time.tm_sec, OMAP_RTC_ALARM_SECONDS_REG);
291
292 reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
293 if (alm->enabled)
294 reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
295 else
296 reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
297 rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
298
299 local_irq_enable();
300
301 return 0;
302}
303
304static struct rtc_class_ops omap_rtc_ops = {
305 .ioctl = omap_rtc_ioctl,
306 .read_time = omap_rtc_read_time,
307 .set_time = omap_rtc_set_time,
308 .read_alarm = omap_rtc_read_alarm,
309 .set_alarm = omap_rtc_set_alarm,
310};
311
312static int omap_rtc_alarm;
313static int omap_rtc_timer;
314
David Brownell71fc8222008-07-23 21:30:38 -0700315static int __init omap_rtc_probe(struct platform_device *pdev)
David Brownelldb68b182006-12-06 20:38:36 -0800316{
317 struct resource *res, *mem;
318 struct rtc_device *rtc;
319 u8 reg, new_ctrl;
320
321 omap_rtc_timer = platform_get_irq(pdev, 0);
322 if (omap_rtc_timer <= 0) {
323 pr_debug("%s: no update irq?\n", pdev->name);
324 return -ENOENT;
325 }
326
327 omap_rtc_alarm = platform_get_irq(pdev, 1);
328 if (omap_rtc_alarm <= 0) {
329 pr_debug("%s: no alarm irq?\n", pdev->name);
330 return -ENOENT;
331 }
332
333 /* NOTE: using static mapping for RTC registers */
334 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
335 if (res && res->start != OMAP_RTC_BASE) {
336 pr_debug("%s: RTC registers at %08x, expected %08x\n",
337 pdev->name, (unsigned) res->start, OMAP_RTC_BASE);
338 return -ENOENT;
339 }
340
341 if (res)
342 mem = request_mem_region(res->start,
343 res->end - res->start + 1,
344 pdev->name);
345 else
346 mem = NULL;
347 if (!mem) {
348 pr_debug("%s: RTC registers at %08x are not free\n",
349 pdev->name, OMAP_RTC_BASE);
350 return -EBUSY;
351 }
352
353 rtc = rtc_device_register(pdev->name, &pdev->dev,
354 &omap_rtc_ops, THIS_MODULE);
355 if (IS_ERR(rtc)) {
356 pr_debug("%s: can't register RTC device, err %ld\n",
357 pdev->name, PTR_ERR(rtc));
358 goto fail;
359 }
360 platform_set_drvdata(pdev, rtc);
David Brownell558a40f2007-05-16 22:11:14 -0700361 dev_set_drvdata(&rtc->dev, mem);
David Brownelldb68b182006-12-06 20:38:36 -0800362
363 /* clear pending irqs, and set 1/second periodic,
364 * which we'll use instead of update irqs
365 */
366 rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
367
368 /* clear old status */
369 reg = rtc_read(OMAP_RTC_STATUS_REG);
370 if (reg & (u8) OMAP_RTC_STATUS_POWER_UP) {
371 pr_info("%s: RTC power up reset detected\n",
372 pdev->name);
373 rtc_write(OMAP_RTC_STATUS_POWER_UP, OMAP_RTC_STATUS_REG);
374 }
375 if (reg & (u8) OMAP_RTC_STATUS_ALARM)
376 rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
377
378 /* handle periodic and alarm irqs */
Thomas Gleixner38515e92007-02-14 00:33:16 -0800379 if (request_irq(omap_rtc_timer, rtc_irq, IRQF_DISABLED,
Kay Sievers744bcb12009-03-24 16:38:22 -0700380 dev_name(&rtc->dev), rtc)) {
David Brownelldb68b182006-12-06 20:38:36 -0800381 pr_debug("%s: RTC timer interrupt IRQ%d already claimed\n",
382 pdev->name, omap_rtc_timer);
383 goto fail0;
384 }
Thomas Gleixner38515e92007-02-14 00:33:16 -0800385 if (request_irq(omap_rtc_alarm, rtc_irq, IRQF_DISABLED,
Kay Sievers744bcb12009-03-24 16:38:22 -0700386 dev_name(&rtc->dev), rtc)) {
David Brownelldb68b182006-12-06 20:38:36 -0800387 pr_debug("%s: RTC alarm interrupt IRQ%d already claimed\n",
388 pdev->name, omap_rtc_alarm);
389 goto fail1;
390 }
391
392 /* On boards with split power, RTC_ON_NOFF won't reset the RTC */
393 reg = rtc_read(OMAP_RTC_CTRL_REG);
394 if (reg & (u8) OMAP_RTC_CTRL_STOP)
395 pr_info("%s: already running\n", pdev->name);
396
397 /* force to 24 hour mode */
398 new_ctrl = reg & ~(OMAP_RTC_CTRL_SPLIT|OMAP_RTC_CTRL_AUTO_COMP);
399 new_ctrl |= OMAP_RTC_CTRL_STOP;
400
401 /* BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE:
402 *
403 * - Boards wired so that RTC_WAKE_INT does something, and muxed
404 * right (W13_1610_RTC_WAKE_INT is the default after chip reset),
405 * should initialize the device wakeup flag appropriately.
406 *
407 * - Boards wired so RTC_ON_nOFF is used as the reset signal,
408 * rather than nPWRON_RESET, should forcibly enable split
409 * power mode. (Some chip errata report that RTC_CTRL_SPLIT
410 * is write-only, and always reads as zero...)
411 */
412 device_init_wakeup(&pdev->dev, 0);
413
414 if (new_ctrl & (u8) OMAP_RTC_CTRL_SPLIT)
415 pr_info("%s: split power mode\n", pdev->name);
416
417 if (reg != new_ctrl)
418 rtc_write(new_ctrl, OMAP_RTC_CTRL_REG);
419
420 return 0;
421
422fail1:
423 free_irq(omap_rtc_timer, NULL);
424fail0:
425 rtc_device_unregister(rtc);
426fail:
427 release_resource(mem);
428 return -EIO;
429}
430
David Brownell71fc8222008-07-23 21:30:38 -0700431static int __exit omap_rtc_remove(struct platform_device *pdev)
David Brownelldb68b182006-12-06 20:38:36 -0800432{
433 struct rtc_device *rtc = platform_get_drvdata(pdev);;
434
435 device_init_wakeup(&pdev->dev, 0);
436
437 /* leave rtc running, but disable irqs */
438 rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
439
440 free_irq(omap_rtc_timer, rtc);
441 free_irq(omap_rtc_alarm, rtc);
442
David Brownell558a40f2007-05-16 22:11:14 -0700443 release_resource(dev_get_drvdata(&rtc->dev));
David Brownelldb68b182006-12-06 20:38:36 -0800444 rtc_device_unregister(rtc);
445 return 0;
446}
447
448#ifdef CONFIG_PM
449
David Brownelldb68b182006-12-06 20:38:36 -0800450static u8 irqstat;
451
452static int omap_rtc_suspend(struct platform_device *pdev, pm_message_t state)
453{
David Brownelldb68b182006-12-06 20:38:36 -0800454 irqstat = rtc_read(OMAP_RTC_INTERRUPTS_REG);
455
456 /* FIXME the RTC alarm is not currently acting as a wakeup event
457 * source, and in fact this enable() call is just saving a flag
458 * that's never used...
459 */
460 if (device_may_wakeup(&pdev->dev))
461 enable_irq_wake(omap_rtc_alarm);
462 else
463 rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
464
465 return 0;
466}
467
468static int omap_rtc_resume(struct platform_device *pdev)
469{
David Brownelldb68b182006-12-06 20:38:36 -0800470 if (device_may_wakeup(&pdev->dev))
471 disable_irq_wake(omap_rtc_alarm);
472 else
473 rtc_write(irqstat, OMAP_RTC_INTERRUPTS_REG);
474 return 0;
475}
476
477#else
478#define omap_rtc_suspend NULL
479#define omap_rtc_resume NULL
480#endif
481
482static void omap_rtc_shutdown(struct platform_device *pdev)
483{
484 rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
485}
486
Kay Sieversad28a072008-04-10 21:29:25 -0700487MODULE_ALIAS("platform:omap_rtc");
David Brownelldb68b182006-12-06 20:38:36 -0800488static struct platform_driver omap_rtc_driver = {
David Brownell71fc8222008-07-23 21:30:38 -0700489 .remove = __exit_p(omap_rtc_remove),
David Brownelldb68b182006-12-06 20:38:36 -0800490 .suspend = omap_rtc_suspend,
491 .resume = omap_rtc_resume,
492 .shutdown = omap_rtc_shutdown,
493 .driver = {
494 .name = "omap_rtc",
495 .owner = THIS_MODULE,
496 },
497};
498
499static int __init rtc_init(void)
500{
David Brownell71fc8222008-07-23 21:30:38 -0700501 return platform_driver_probe(&omap_rtc_driver, omap_rtc_probe);
David Brownelldb68b182006-12-06 20:38:36 -0800502}
503module_init(rtc_init);
504
505static void __exit rtc_exit(void)
506{
507 platform_driver_unregister(&omap_rtc_driver);
508}
509module_exit(rtc_exit);
510
511MODULE_AUTHOR("George G. Davis (and others)");
512MODULE_LICENSE("GPL");