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Andrew Victor788b1fc2006-06-25 05:48:27 -07001/*
2 * Real Time Clock interface for Linux on Atmel AT91RM9200
3 *
4 * Copyright (C) 2002 Rick Bronson
5 *
6 * Converted to RTC class model by Andrew Victor
7 *
8 * Ported to Linux 2.6 by Steven Scholz
9 * Based on s3c2410-rtc.c Simtec Electronics
10 *
11 * Based on sa1100-rtc.c by Nils Faerber
12 * Based on rtc.c by Paul Gortmaker
13 *
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version
17 * 2 of the License, or (at your option) any later version.
18 *
19 */
20
21#include <linux/module.h>
22#include <linux/kernel.h>
23#include <linux/platform_device.h>
24#include <linux/time.h>
25#include <linux/rtc.h>
26#include <linux/bcd.h>
27#include <linux/interrupt.h>
28#include <linux/ioctl.h>
29#include <linux/completion.h>
30
31#include <asm/uaccess.h>
32#include <asm/rtc.h>
33
34#include <asm/mach/time.h>
35
David Brownelld73e3cd2007-01-05 16:36:25 -080036#include <asm/arch/at91_rtc.h>
37
Andrew Victor788b1fc2006-06-25 05:48:27 -070038
39#define AT91_RTC_FREQ 1
40#define AT91_RTC_EPOCH 1900UL /* just like arch/arm/common/rtctime.c */
41
42static DECLARE_COMPLETION(at91_rtc_updated);
43static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
44
Andrew Victor788b1fc2006-06-25 05:48:27 -070045/*
46 * Decode time/date into rtc_time structure
47 */
Andrew Mortone7a8bb12006-06-25 05:48:27 -070048static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
49 struct rtc_time *tm)
Andrew Victor788b1fc2006-06-25 05:48:27 -070050{
51 unsigned int time, date;
52
53 /* must read twice in case it changes */
54 do {
55 time = at91_sys_read(timereg);
56 date = at91_sys_read(calreg);
Andrew Mortone7a8bb12006-06-25 05:48:27 -070057 } while ((time != at91_sys_read(timereg)) ||
58 (date != at91_sys_read(calreg)));
Andrew Victor788b1fc2006-06-25 05:48:27 -070059
60 tm->tm_sec = BCD2BIN((time & AT91_RTC_SEC) >> 0);
61 tm->tm_min = BCD2BIN((time & AT91_RTC_MIN) >> 8);
62 tm->tm_hour = BCD2BIN((time & AT91_RTC_HOUR) >> 16);
63
64 /*
65 * The Calendar Alarm register does not have a field for
66 * the year - so these will return an invalid value. When an
67 * alarm is set, at91_alarm_year wille store the current year.
68 */
Andrew Mortone7a8bb12006-06-25 05:48:27 -070069 tm->tm_year = BCD2BIN(date & AT91_RTC_CENT) * 100; /* century */
70 tm->tm_year += BCD2BIN((date & AT91_RTC_YEAR) >> 8); /* year */
Andrew Victor788b1fc2006-06-25 05:48:27 -070071
72 tm->tm_wday = BCD2BIN((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */
73 tm->tm_mon = BCD2BIN((date & AT91_RTC_MONTH) >> 16) - 1;
74 tm->tm_mday = BCD2BIN((date & AT91_RTC_DATE) >> 24);
75}
76
77/*
78 * Read current time and date in RTC
79 */
80static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
81{
82 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
83 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
84 tm->tm_year = tm->tm_year - 1900;
85
86 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
Andrew Mortone7a8bb12006-06-25 05:48:27 -070087 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
88 tm->tm_hour, tm->tm_min, tm->tm_sec);
Andrew Victor788b1fc2006-06-25 05:48:27 -070089
90 return 0;
91}
92
93/*
94 * Set current time and date in RTC
95 */
96static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
97{
98 unsigned long cr;
99
100 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700101 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
102 tm->tm_hour, tm->tm_min, tm->tm_sec);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700103
104 /* Stop Time/Calendar from counting */
105 cr = at91_sys_read(AT91_RTC_CR);
106 at91_sys_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
107
108 at91_sys_write(AT91_RTC_IER, AT91_RTC_ACKUPD);
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700109 wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
Andrew Victor788b1fc2006-06-25 05:48:27 -0700110 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD);
111
112 at91_sys_write(AT91_RTC_TIMR,
113 BIN2BCD(tm->tm_sec) << 0
114 | BIN2BCD(tm->tm_min) << 8
115 | BIN2BCD(tm->tm_hour) << 16);
116
117 at91_sys_write(AT91_RTC_CALR,
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700118 BIN2BCD((tm->tm_year + 1900) / 100) /* century */
119 | BIN2BCD(tm->tm_year % 100) << 8 /* year */
120 | BIN2BCD(tm->tm_mon + 1) << 16 /* tm_mon starts at zero */
121 | BIN2BCD(tm->tm_wday + 1) << 21 /* day of the week [0-6], Sunday=0 */
Andrew Victor788b1fc2006-06-25 05:48:27 -0700122 | BIN2BCD(tm->tm_mday) << 24);
123
124 /* Restart Time/Calendar */
125 cr = at91_sys_read(AT91_RTC_CR);
126 at91_sys_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
127
128 return 0;
129}
130
131/*
132 * Read alarm time and date in RTC
133 */
134static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
135{
136 struct rtc_time *tm = &alrm->time;
137
138 at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
139 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
140 tm->tm_year = at91_alarm_year - 1900;
141
David Brownella2db8df2006-12-13 00:35:08 -0800142 alrm->enabled = (at91_sys_read(AT91_RTC_IMR) & AT91_RTC_ALARM)
143 ? 1 : 0;
144
Andrew Victor788b1fc2006-06-25 05:48:27 -0700145 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700146 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
147 tm->tm_hour, tm->tm_min, tm->tm_sec);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700148
149 return 0;
150}
151
152/*
153 * Set alarm time and date in RTC
154 */
155static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
156{
157 struct rtc_time tm;
158
159 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm);
160
161 at91_alarm_year = tm.tm_year;
162
163 tm.tm_hour = alrm->time.tm_hour;
164 tm.tm_min = alrm->time.tm_min;
165 tm.tm_sec = alrm->time.tm_sec;
166
167 at91_sys_write(AT91_RTC_TIMALR,
168 BIN2BCD(tm.tm_sec) << 0
169 | BIN2BCD(tm.tm_min) << 8
170 | BIN2BCD(tm.tm_hour) << 16
171 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
172 at91_sys_write(AT91_RTC_CALALR,
173 BIN2BCD(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */
174 | BIN2BCD(tm.tm_mday) << 24
175 | AT91_RTC_DATEEN | AT91_RTC_MTHEN);
176
177 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700178 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
179 tm.tm_min, tm.tm_sec);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700180
181 return 0;
182}
183
184/*
185 * Handle commands from user-space
186 */
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700187static int at91_rtc_ioctl(struct device *dev, unsigned int cmd,
188 unsigned long arg)
Andrew Victor788b1fc2006-06-25 05:48:27 -0700189{
190 int ret = 0;
191
192 pr_debug("%s(): cmd=%08x, arg=%08lx.\n", __FUNCTION__, cmd, arg);
193
194 switch (cmd) {
195 case RTC_AIE_OFF: /* alarm off */
196 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
197 break;
198 case RTC_AIE_ON: /* alarm on */
199 at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
200 break;
201 case RTC_UIE_OFF: /* update off */
202 case RTC_PIE_OFF: /* periodic off */
203 at91_sys_write(AT91_RTC_IDR, AT91_RTC_SECEV);
204 break;
205 case RTC_UIE_ON: /* update on */
206 case RTC_PIE_ON: /* periodic on */
207 at91_sys_write(AT91_RTC_IER, AT91_RTC_SECEV);
208 break;
209 case RTC_IRQP_READ: /* read periodic alarm frequency */
210 ret = put_user(AT91_RTC_FREQ, (unsigned long *) arg);
211 break;
212 case RTC_IRQP_SET: /* set periodic alarm frequency */
213 if (arg != AT91_RTC_FREQ)
214 ret = -EINVAL;
215 break;
216 default:
217 ret = -ENOIOCTLCMD;
218 break;
219 }
220
221 return ret;
222}
223
224/*
225 * Provide additional RTC information in /proc/driver/rtc
226 */
227static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
228{
229 unsigned long imr = at91_sys_read(AT91_RTC_IMR);
230
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700231 seq_printf(seq, "update_IRQ\t: %s\n",
232 (imr & AT91_RTC_ACKUPD) ? "yes" : "no");
233 seq_printf(seq, "periodic_IRQ\t: %s\n",
234 (imr & AT91_RTC_SECEV) ? "yes" : "no");
235 seq_printf(seq, "periodic_freq\t: %ld\n",
236 (unsigned long) AT91_RTC_FREQ);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700237
238 return 0;
239}
240
241/*
242 * IRQ handler for the RTC
243 */
David Howells7d12e782006-10-05 14:55:46 +0100244static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
Andrew Victor788b1fc2006-06-25 05:48:27 -0700245{
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700246 struct platform_device *pdev = dev_id;
Andrew Victor788b1fc2006-06-25 05:48:27 -0700247 struct rtc_device *rtc = platform_get_drvdata(pdev);
248 unsigned int rtsr;
249 unsigned long events = 0;
250
251 rtsr = at91_sys_read(AT91_RTC_SR) & at91_sys_read(AT91_RTC_IMR);
252 if (rtsr) { /* this interrupt is shared! Is it ours? */
253 if (rtsr & AT91_RTC_ALARM)
254 events |= (RTC_AF | RTC_IRQF);
255 if (rtsr & AT91_RTC_SECEV)
256 events |= (RTC_UF | RTC_IRQF);
257 if (rtsr & AT91_RTC_ACKUPD)
258 complete(&at91_rtc_updated);
259
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700260 at91_sys_write(AT91_RTC_SCCR, rtsr); /* clear status reg */
Andrew Victor788b1fc2006-06-25 05:48:27 -0700261
262 rtc_update_irq(&rtc->class_dev, 1, events);
263
264 pr_debug("%s(): num=%ld, events=0x%02lx\n", __FUNCTION__,
265 events >> 8, events & 0x000000FF);
266
267 return IRQ_HANDLED;
268 }
269 return IRQ_NONE; /* not handled */
270}
271
David Brownellff8371a2006-09-30 23:28:17 -0700272static const struct rtc_class_ops at91_rtc_ops = {
Andrew Victor788b1fc2006-06-25 05:48:27 -0700273 .ioctl = at91_rtc_ioctl,
274 .read_time = at91_rtc_readtime,
275 .set_time = at91_rtc_settime,
276 .read_alarm = at91_rtc_readalarm,
277 .set_alarm = at91_rtc_setalarm,
278 .proc = at91_rtc_proc,
279};
280
281/*
282 * Initialize and install RTC driver
283 */
284static int __init at91_rtc_probe(struct platform_device *pdev)
285{
286 struct rtc_device *rtc;
287 int ret;
288
289 at91_sys_write(AT91_RTC_CR, 0);
290 at91_sys_write(AT91_RTC_MR, 0); /* 24 hour mode */
291
292 /* Disable all interrupts */
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700293 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
294 AT91_RTC_SECEV | AT91_RTC_TIMEV |
295 AT91_RTC_CALEV);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700296
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700297 ret = request_irq(AT91_ID_SYS, at91_rtc_interrupt,
David Brownelld728b1e2006-11-25 11:09:28 -0800298 IRQF_DISABLED | IRQF_SHARED,
299 "at91_rtc", pdev);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700300 if (ret) {
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700301 printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n",
302 AT91_ID_SYS);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700303 return ret;
304 }
305
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700306 rtc = rtc_device_register(pdev->name, &pdev->dev,
307 &at91_rtc_ops, THIS_MODULE);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700308 if (IS_ERR(rtc)) {
309 free_irq(AT91_ID_SYS, pdev);
310 return PTR_ERR(rtc);
311 }
312 platform_set_drvdata(pdev, rtc);
David Brownell90b4d642006-09-30 23:28:17 -0700313 device_init_wakeup(&pdev->dev, 1);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700314
315 printk(KERN_INFO "AT91 Real Time Clock driver.\n");
316 return 0;
317}
318
319/*
320 * Disable and remove the RTC driver
321 */
322static int __devexit at91_rtc_remove(struct platform_device *pdev)
323{
324 struct rtc_device *rtc = platform_get_drvdata(pdev);
325
326 /* Disable all interrupts */
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700327 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
328 AT91_RTC_SECEV | AT91_RTC_TIMEV |
329 AT91_RTC_CALEV);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700330 free_irq(AT91_ID_SYS, pdev);
331
332 rtc_device_unregister(rtc);
333 platform_set_drvdata(pdev, NULL);
David Brownell90b4d642006-09-30 23:28:17 -0700334 device_init_wakeup(&pdev->dev, 0);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700335
336 return 0;
337}
338
339#ifdef CONFIG_PM
340
341/* AT91RM9200 RTC Power management control */
342
343static struct timespec at91_rtc_delta;
David Brownell90b4d642006-09-30 23:28:17 -0700344static u32 at91_rtc_imr;
Andrew Victor788b1fc2006-06-25 05:48:27 -0700345
346static int at91_rtc_suspend(struct platform_device *pdev, pm_message_t state)
347{
348 struct rtc_time tm;
349 struct timespec time;
350
351 time.tv_nsec = 0;
352
353 /* calculate time delta for suspend */
354 at91_rtc_readtime(&pdev->dev, &tm);
355 rtc_tm_to_time(&tm, &time.tv_sec);
356 save_time_delta(&at91_rtc_delta, &time);
357
David Brownell90b4d642006-09-30 23:28:17 -0700358 /* this IRQ is shared with DBGU and other hardware which isn't
359 * necessarily doing PM like we are...
360 */
361 at91_rtc_imr = at91_sys_read(AT91_RTC_IMR)
362 & (AT91_RTC_ALARM|AT91_RTC_SECEV);
363 if (at91_rtc_imr) {
364 if (device_may_wakeup(&pdev->dev))
365 enable_irq_wake(AT91_ID_SYS);
366 else
367 at91_sys_write(AT91_RTC_IDR, at91_rtc_imr);
368 }
369
Andrew Victor788b1fc2006-06-25 05:48:27 -0700370 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700371 1900 + tm.tm_year, tm.tm_mon, tm.tm_mday,
372 tm.tm_hour, tm.tm_min, tm.tm_sec);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700373
374 return 0;
375}
376
377static int at91_rtc_resume(struct platform_device *pdev)
378{
379 struct rtc_time tm;
380 struct timespec time;
381
382 time.tv_nsec = 0;
383
384 at91_rtc_readtime(&pdev->dev, &tm);
385 rtc_tm_to_time(&tm, &time.tv_sec);
386 restore_time_delta(&at91_rtc_delta, &time);
387
David Brownell90b4d642006-09-30 23:28:17 -0700388 if (at91_rtc_imr) {
389 if (device_may_wakeup(&pdev->dev))
390 disable_irq_wake(AT91_ID_SYS);
391 else
392 at91_sys_write(AT91_RTC_IER, at91_rtc_imr);
393 }
394
Andrew Victor788b1fc2006-06-25 05:48:27 -0700395 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700396 1900 + tm.tm_year, tm.tm_mon, tm.tm_mday,
397 tm.tm_hour, tm.tm_min, tm.tm_sec);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700398
399 return 0;
400}
401#else
402#define at91_rtc_suspend NULL
403#define at91_rtc_resume NULL
404#endif
405
406static struct platform_driver at91_rtc_driver = {
407 .probe = at91_rtc_probe,
408 .remove = at91_rtc_remove,
409 .suspend = at91_rtc_suspend,
410 .resume = at91_rtc_resume,
411 .driver = {
412 .name = "at91_rtc",
413 .owner = THIS_MODULE,
414 },
415};
416
417static int __init at91_rtc_init(void)
418{
419 return platform_driver_register(&at91_rtc_driver);
420}
421
422static void __exit at91_rtc_exit(void)
423{
424 platform_driver_unregister(&at91_rtc_driver);
425}
426
Andrew Victor788b1fc2006-06-25 05:48:27 -0700427module_init(at91_rtc_init);
428module_exit(at91_rtc_exit);
429
430MODULE_AUTHOR("Rick Bronson");
431MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
432MODULE_LICENSE("GPL");