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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>
Russell Kinga09e64f2008-08-05 16:14:15 +010032#include <mach/at91_rtc.h>
David Brownelld73e3cd2007-01-05 16:36:25 -080033
Andrew Victor788b1fc2006-06-25 05:48:27 -070034
35#define AT91_RTC_FREQ 1
36#define AT91_RTC_EPOCH 1900UL /* just like arch/arm/common/rtctime.c */
37
38static DECLARE_COMPLETION(at91_rtc_updated);
39static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
40
Andrew Victor788b1fc2006-06-25 05:48:27 -070041/*
42 * Decode time/date into rtc_time structure
43 */
Andrew Mortone7a8bb12006-06-25 05:48:27 -070044static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
45 struct rtc_time *tm)
Andrew Victor788b1fc2006-06-25 05:48:27 -070046{
47 unsigned int time, date;
48
49 /* must read twice in case it changes */
50 do {
51 time = at91_sys_read(timereg);
52 date = at91_sys_read(calreg);
Andrew Mortone7a8bb12006-06-25 05:48:27 -070053 } while ((time != at91_sys_read(timereg)) ||
54 (date != at91_sys_read(calreg)));
Andrew Victor788b1fc2006-06-25 05:48:27 -070055
56 tm->tm_sec = BCD2BIN((time & AT91_RTC_SEC) >> 0);
57 tm->tm_min = BCD2BIN((time & AT91_RTC_MIN) >> 8);
58 tm->tm_hour = BCD2BIN((time & AT91_RTC_HOUR) >> 16);
59
60 /*
61 * The Calendar Alarm register does not have a field for
62 * the year - so these will return an invalid value. When an
63 * alarm is set, at91_alarm_year wille store the current year.
64 */
Andrew Mortone7a8bb12006-06-25 05:48:27 -070065 tm->tm_year = BCD2BIN(date & AT91_RTC_CENT) * 100; /* century */
66 tm->tm_year += BCD2BIN((date & AT91_RTC_YEAR) >> 8); /* year */
Andrew Victor788b1fc2006-06-25 05:48:27 -070067
68 tm->tm_wday = BCD2BIN((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */
69 tm->tm_mon = BCD2BIN((date & AT91_RTC_MONTH) >> 16) - 1;
70 tm->tm_mday = BCD2BIN((date & AT91_RTC_DATE) >> 24);
71}
72
73/*
74 * Read current time and date in RTC
75 */
76static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
77{
78 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
79 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
80 tm->tm_year = tm->tm_year - 1900;
81
Harvey Harrison2a4e2b82008-04-28 02:12:00 -070082 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
Andrew Mortone7a8bb12006-06-25 05:48:27 -070083 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
84 tm->tm_hour, tm->tm_min, tm->tm_sec);
Andrew Victor788b1fc2006-06-25 05:48:27 -070085
86 return 0;
87}
88
89/*
90 * Set current time and date in RTC
91 */
92static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
93{
94 unsigned long cr;
95
Harvey Harrison2a4e2b82008-04-28 02:12:00 -070096 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
Andrew Mortone7a8bb12006-06-25 05:48:27 -070097 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
98 tm->tm_hour, tm->tm_min, tm->tm_sec);
Andrew Victor788b1fc2006-06-25 05:48:27 -070099
100 /* Stop Time/Calendar from counting */
101 cr = at91_sys_read(AT91_RTC_CR);
102 at91_sys_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
103
104 at91_sys_write(AT91_RTC_IER, AT91_RTC_ACKUPD);
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700105 wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
Andrew Victor788b1fc2006-06-25 05:48:27 -0700106 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD);
107
108 at91_sys_write(AT91_RTC_TIMR,
109 BIN2BCD(tm->tm_sec) << 0
110 | BIN2BCD(tm->tm_min) << 8
111 | BIN2BCD(tm->tm_hour) << 16);
112
113 at91_sys_write(AT91_RTC_CALR,
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700114 BIN2BCD((tm->tm_year + 1900) / 100) /* century */
115 | BIN2BCD(tm->tm_year % 100) << 8 /* year */
116 | BIN2BCD(tm->tm_mon + 1) << 16 /* tm_mon starts at zero */
117 | BIN2BCD(tm->tm_wday + 1) << 21 /* day of the week [0-6], Sunday=0 */
Andrew Victor788b1fc2006-06-25 05:48:27 -0700118 | BIN2BCD(tm->tm_mday) << 24);
119
120 /* Restart Time/Calendar */
121 cr = at91_sys_read(AT91_RTC_CR);
122 at91_sys_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
123
124 return 0;
125}
126
127/*
128 * Read alarm time and date in RTC
129 */
130static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
131{
132 struct rtc_time *tm = &alrm->time;
133
134 at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
135 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
136 tm->tm_year = at91_alarm_year - 1900;
137
David Brownella2db8df2006-12-13 00:35:08 -0800138 alrm->enabled = (at91_sys_read(AT91_RTC_IMR) & AT91_RTC_ALARM)
139 ? 1 : 0;
140
Harvey Harrison2a4e2b82008-04-28 02:12:00 -0700141 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700142 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
143 tm->tm_hour, tm->tm_min, tm->tm_sec);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700144
145 return 0;
146}
147
148/*
149 * Set alarm time and date in RTC
150 */
151static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
152{
153 struct rtc_time tm;
154
155 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm);
156
157 at91_alarm_year = tm.tm_year;
158
159 tm.tm_hour = alrm->time.tm_hour;
160 tm.tm_min = alrm->time.tm_min;
161 tm.tm_sec = alrm->time.tm_sec;
162
David Brownell5d4675a2007-02-20 13:58:14 -0800163 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700164 at91_sys_write(AT91_RTC_TIMALR,
165 BIN2BCD(tm.tm_sec) << 0
166 | BIN2BCD(tm.tm_min) << 8
167 | BIN2BCD(tm.tm_hour) << 16
168 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
169 at91_sys_write(AT91_RTC_CALALR,
170 BIN2BCD(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */
171 | BIN2BCD(tm.tm_mday) << 24
172 | AT91_RTC_DATEEN | AT91_RTC_MTHEN);
173
David Brownell449321b2008-07-23 21:30:46 -0700174 if (alrm->enabled) {
175 at91_sys_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
David Brownell5d4675a2007-02-20 13:58:14 -0800176 at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
David Brownell449321b2008-07-23 21:30:46 -0700177 }
David Brownell5d4675a2007-02-20 13:58:14 -0800178
Harvey Harrison2a4e2b82008-04-28 02:12:00 -0700179 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700180 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
181 tm.tm_min, tm.tm_sec);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700182
183 return 0;
184}
185
186/*
187 * Handle commands from user-space
188 */
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700189static int at91_rtc_ioctl(struct device *dev, unsigned int cmd,
190 unsigned long arg)
Andrew Victor788b1fc2006-06-25 05:48:27 -0700191{
192 int ret = 0;
193
Harvey Harrison2a4e2b82008-04-28 02:12:00 -0700194 pr_debug("%s(): cmd=%08x, arg=%08lx.\n", __func__, cmd, arg);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700195
David Brownell449321b2008-07-23 21:30:46 -0700196 /* important: scrub old status before enabling IRQs */
Andrew Victor788b1fc2006-06-25 05:48:27 -0700197 switch (cmd) {
198 case RTC_AIE_OFF: /* alarm off */
199 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
200 break;
201 case RTC_AIE_ON: /* alarm on */
David Brownell449321b2008-07-23 21:30:46 -0700202 at91_sys_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700203 at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
204 break;
205 case RTC_UIE_OFF: /* update off */
Andrew Victor788b1fc2006-06-25 05:48:27 -0700206 at91_sys_write(AT91_RTC_IDR, AT91_RTC_SECEV);
207 break;
208 case RTC_UIE_ON: /* update on */
David Brownell449321b2008-07-23 21:30:46 -0700209 at91_sys_write(AT91_RTC_SCCR, AT91_RTC_SECEV);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700210 at91_sys_write(AT91_RTC_IER, AT91_RTC_SECEV);
211 break;
Andrew Victor788b1fc2006-06-25 05:48:27 -0700212 default:
213 ret = -ENOIOCTLCMD;
214 break;
215 }
216
217 return ret;
218}
219
220/*
221 * Provide additional RTC information in /proc/driver/rtc
222 */
223static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
224{
225 unsigned long imr = at91_sys_read(AT91_RTC_IMR);
226
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700227 seq_printf(seq, "update_IRQ\t: %s\n",
228 (imr & AT91_RTC_ACKUPD) ? "yes" : "no");
229 seq_printf(seq, "periodic_IRQ\t: %s\n",
230 (imr & AT91_RTC_SECEV) ? "yes" : "no");
231 seq_printf(seq, "periodic_freq\t: %ld\n",
232 (unsigned long) AT91_RTC_FREQ);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700233
234 return 0;
235}
236
237/*
238 * IRQ handler for the RTC
239 */
David Howells7d12e782006-10-05 14:55:46 +0100240static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
Andrew Victor788b1fc2006-06-25 05:48:27 -0700241{
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700242 struct platform_device *pdev = dev_id;
Andrew Victor788b1fc2006-06-25 05:48:27 -0700243 struct rtc_device *rtc = platform_get_drvdata(pdev);
244 unsigned int rtsr;
245 unsigned long events = 0;
246
247 rtsr = at91_sys_read(AT91_RTC_SR) & at91_sys_read(AT91_RTC_IMR);
248 if (rtsr) { /* this interrupt is shared! Is it ours? */
249 if (rtsr & AT91_RTC_ALARM)
250 events |= (RTC_AF | RTC_IRQF);
251 if (rtsr & AT91_RTC_SECEV)
252 events |= (RTC_UF | RTC_IRQF);
253 if (rtsr & AT91_RTC_ACKUPD)
254 complete(&at91_rtc_updated);
255
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700256 at91_sys_write(AT91_RTC_SCCR, rtsr); /* clear status reg */
Andrew Victor788b1fc2006-06-25 05:48:27 -0700257
David Brownellab6a2d72007-05-08 00:33:30 -0700258 rtc_update_irq(rtc, 1, events);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700259
Harvey Harrison2a4e2b82008-04-28 02:12:00 -0700260 pr_debug("%s(): num=%ld, events=0x%02lx\n", __func__,
Andrew Victor788b1fc2006-06-25 05:48:27 -0700261 events >> 8, events & 0x000000FF);
262
263 return IRQ_HANDLED;
264 }
265 return IRQ_NONE; /* not handled */
266}
267
David Brownellff8371a2006-09-30 23:28:17 -0700268static const struct rtc_class_ops at91_rtc_ops = {
Andrew Victor788b1fc2006-06-25 05:48:27 -0700269 .ioctl = at91_rtc_ioctl,
270 .read_time = at91_rtc_readtime,
271 .set_time = at91_rtc_settime,
272 .read_alarm = at91_rtc_readalarm,
273 .set_alarm = at91_rtc_setalarm,
274 .proc = at91_rtc_proc,
275};
276
277/*
278 * Initialize and install RTC driver
279 */
280static int __init at91_rtc_probe(struct platform_device *pdev)
281{
282 struct rtc_device *rtc;
283 int ret;
284
285 at91_sys_write(AT91_RTC_CR, 0);
286 at91_sys_write(AT91_RTC_MR, 0); /* 24 hour mode */
287
288 /* Disable all interrupts */
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700289 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
290 AT91_RTC_SECEV | AT91_RTC_TIMEV |
291 AT91_RTC_CALEV);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700292
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700293 ret = request_irq(AT91_ID_SYS, at91_rtc_interrupt,
David Brownelld728b1e2006-11-25 11:09:28 -0800294 IRQF_DISABLED | IRQF_SHARED,
295 "at91_rtc", pdev);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700296 if (ret) {
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700297 printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n",
298 AT91_ID_SYS);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700299 return ret;
300 }
301
David Brownell5d4675a2007-02-20 13:58:14 -0800302 /* cpu init code should really have flagged this device as
303 * being wake-capable; if it didn't, do that here.
304 */
305 if (!device_can_wakeup(&pdev->dev))
306 device_init_wakeup(&pdev->dev, 1);
307
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700308 rtc = rtc_device_register(pdev->name, &pdev->dev,
309 &at91_rtc_ops, THIS_MODULE);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700310 if (IS_ERR(rtc)) {
311 free_irq(AT91_ID_SYS, pdev);
312 return PTR_ERR(rtc);
313 }
314 platform_set_drvdata(pdev, rtc);
315
316 printk(KERN_INFO "AT91 Real Time Clock driver.\n");
317 return 0;
318}
319
320/*
321 * Disable and remove the RTC driver
322 */
David Brownell5d4675a2007-02-20 13:58:14 -0800323static int __exit at91_rtc_remove(struct platform_device *pdev)
Andrew Victor788b1fc2006-06-25 05:48:27 -0700324{
325 struct rtc_device *rtc = platform_get_drvdata(pdev);
326
327 /* Disable all interrupts */
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700328 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
329 AT91_RTC_SECEV | AT91_RTC_TIMEV |
330 AT91_RTC_CALEV);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700331 free_irq(AT91_ID_SYS, pdev);
332
333 rtc_device_unregister(rtc);
334 platform_set_drvdata(pdev, NULL);
335
336 return 0;
337}
338
339#ifdef CONFIG_PM
340
341/* AT91RM9200 RTC Power management control */
342
David Brownell90b4d642006-09-30 23:28:17 -0700343static u32 at91_rtc_imr;
Andrew Victor788b1fc2006-06-25 05:48:27 -0700344
345static int at91_rtc_suspend(struct platform_device *pdev, pm_message_t state)
346{
David Brownell90b4d642006-09-30 23:28:17 -0700347 /* this IRQ is shared with DBGU and other hardware which isn't
348 * necessarily doing PM like we are...
349 */
350 at91_rtc_imr = at91_sys_read(AT91_RTC_IMR)
351 & (AT91_RTC_ALARM|AT91_RTC_SECEV);
352 if (at91_rtc_imr) {
353 if (device_may_wakeup(&pdev->dev))
354 enable_irq_wake(AT91_ID_SYS);
355 else
356 at91_sys_write(AT91_RTC_IDR, at91_rtc_imr);
357 }
Andrew Victor788b1fc2006-06-25 05:48:27 -0700358 return 0;
359}
360
361static int at91_rtc_resume(struct platform_device *pdev)
362{
David Brownell90b4d642006-09-30 23:28:17 -0700363 if (at91_rtc_imr) {
364 if (device_may_wakeup(&pdev->dev))
365 disable_irq_wake(AT91_ID_SYS);
366 else
367 at91_sys_write(AT91_RTC_IER, at91_rtc_imr);
368 }
Andrew Victor788b1fc2006-06-25 05:48:27 -0700369 return 0;
370}
371#else
372#define at91_rtc_suspend NULL
373#define at91_rtc_resume NULL
374#endif
375
376static struct platform_driver at91_rtc_driver = {
David Brownell5d4675a2007-02-20 13:58:14 -0800377 .remove = __exit_p(at91_rtc_remove),
Andrew Victor788b1fc2006-06-25 05:48:27 -0700378 .suspend = at91_rtc_suspend,
379 .resume = at91_rtc_resume,
380 .driver = {
381 .name = "at91_rtc",
382 .owner = THIS_MODULE,
383 },
384};
385
386static int __init at91_rtc_init(void)
387{
David Brownell5d4675a2007-02-20 13:58:14 -0800388 return platform_driver_probe(&at91_rtc_driver, at91_rtc_probe);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700389}
390
391static void __exit at91_rtc_exit(void)
392{
393 platform_driver_unregister(&at91_rtc_driver);
394}
395
Andrew Victor788b1fc2006-06-25 05:48:27 -0700396module_init(at91_rtc_init);
397module_exit(at91_rtc_exit);
398
399MODULE_AUTHOR("Rick Bronson");
400MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
401MODULE_LICENSE("GPL");
Kay Sieversad28a072008-04-10 21:29:25 -0700402MODULE_ALIAS("platform:at91_rtc");