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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>
Andrew Victorfb0d4ec2008-10-15 22:03:08 -070032
Russell Kinga09e64f2008-08-05 16:14:15 +010033#include <mach/at91_rtc.h>
David Brownelld73e3cd2007-01-05 16:36:25 -080034
Andrew Victor788b1fc2006-06-25 05:48:27 -070035
Andrew Victor788b1fc2006-06-25 05:48:27 -070036#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
Adrian Bunkfe20ba72008-10-18 20:28:41 -070056 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);
Andrew Victor788b1fc2006-06-25 05:48:27 -070059
60 /*
61 * The Calendar Alarm register does not have a field for
62 * the year - so these will return an invalid value. When an
Lucas De Marchi25985ed2011-03-30 22:57:33 -030063 * alarm is set, at91_alarm_year will store the current year.
Andrew Victor788b1fc2006-06-25 05:48:27 -070064 */
Adrian Bunkfe20ba72008-10-18 20:28:41 -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
Adrian Bunkfe20ba72008-10-18 20:28:41 -070068 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);
Andrew Victor788b1fc2006-06-25 05:48:27 -070071}
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,
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700109 bin2bcd(tm->tm_sec) << 0
110 | bin2bcd(tm->tm_min) << 8
111 | bin2bcd(tm->tm_hour) << 16);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700112
113 at91_sys_write(AT91_RTC_CALR,
Adrian Bunkfe20ba72008-10-18 20:28:41 -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 */
118 | bin2bcd(tm->tm_mday) << 24);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700119
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,
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700165 bin2bcd(tm.tm_sec) << 0
166 | bin2bcd(tm.tm_min) << 8
167 | bin2bcd(tm.tm_hour) << 16
Andrew Victor788b1fc2006-06-25 05:48:27 -0700168 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
169 at91_sys_write(AT91_RTC_CALALR,
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700170 bin2bcd(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */
171 | bin2bcd(tm.tm_mday) << 24
Andrew Victor788b1fc2006-06-25 05:48:27 -0700172 | 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
John Stultz16380c12011-02-02 17:02:41 -0800186static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
187{
188 pr_debug("%s(): cmd=%08x\n", __func__, enabled);
189
190 if (enabled) {
191 at91_sys_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
192 at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
193 } else
194 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
195
196 return 0;
197}
Andrew Victor788b1fc2006-06-25 05:48:27 -0700198/*
199 * Provide additional RTC information in /proc/driver/rtc
200 */
201static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
202{
203 unsigned long imr = at91_sys_read(AT91_RTC_IMR);
204
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700205 seq_printf(seq, "update_IRQ\t: %s\n",
206 (imr & AT91_RTC_ACKUPD) ? "yes" : "no");
207 seq_printf(seq, "periodic_IRQ\t: %s\n",
208 (imr & AT91_RTC_SECEV) ? "yes" : "no");
Andrew Victor788b1fc2006-06-25 05:48:27 -0700209
210 return 0;
211}
212
213/*
214 * IRQ handler for the RTC
215 */
David Howells7d12e782006-10-05 14:55:46 +0100216static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
Andrew Victor788b1fc2006-06-25 05:48:27 -0700217{
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700218 struct platform_device *pdev = dev_id;
Andrew Victor788b1fc2006-06-25 05:48:27 -0700219 struct rtc_device *rtc = platform_get_drvdata(pdev);
220 unsigned int rtsr;
221 unsigned long events = 0;
222
223 rtsr = at91_sys_read(AT91_RTC_SR) & at91_sys_read(AT91_RTC_IMR);
224 if (rtsr) { /* this interrupt is shared! Is it ours? */
225 if (rtsr & AT91_RTC_ALARM)
226 events |= (RTC_AF | RTC_IRQF);
227 if (rtsr & AT91_RTC_SECEV)
228 events |= (RTC_UF | RTC_IRQF);
229 if (rtsr & AT91_RTC_ACKUPD)
230 complete(&at91_rtc_updated);
231
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700232 at91_sys_write(AT91_RTC_SCCR, rtsr); /* clear status reg */
Andrew Victor788b1fc2006-06-25 05:48:27 -0700233
David Brownellab6a2d72007-05-08 00:33:30 -0700234 rtc_update_irq(rtc, 1, events);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700235
Harvey Harrison2a4e2b82008-04-28 02:12:00 -0700236 pr_debug("%s(): num=%ld, events=0x%02lx\n", __func__,
Andrew Victor788b1fc2006-06-25 05:48:27 -0700237 events >> 8, events & 0x000000FF);
238
239 return IRQ_HANDLED;
240 }
241 return IRQ_NONE; /* not handled */
242}
243
David Brownellff8371a2006-09-30 23:28:17 -0700244static const struct rtc_class_ops at91_rtc_ops = {
Andrew Victor788b1fc2006-06-25 05:48:27 -0700245 .read_time = at91_rtc_readtime,
246 .set_time = at91_rtc_settime,
247 .read_alarm = at91_rtc_readalarm,
248 .set_alarm = at91_rtc_setalarm,
249 .proc = at91_rtc_proc,
John Stultz16380c12011-02-02 17:02:41 -0800250 .alarm_irq_enable = at91_rtc_alarm_irq_enable,
Andrew Victor788b1fc2006-06-25 05:48:27 -0700251};
252
253/*
254 * Initialize and install RTC driver
255 */
256static int __init at91_rtc_probe(struct platform_device *pdev)
257{
258 struct rtc_device *rtc;
259 int ret;
260
261 at91_sys_write(AT91_RTC_CR, 0);
262 at91_sys_write(AT91_RTC_MR, 0); /* 24 hour mode */
263
264 /* Disable all interrupts */
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700265 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
266 AT91_RTC_SECEV | AT91_RTC_TIMEV |
267 AT91_RTC_CALEV);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700268
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700269 ret = request_irq(AT91_ID_SYS, at91_rtc_interrupt,
David Brownelldac94d92009-09-22 16:46:31 -0700270 IRQF_SHARED,
David Brownelld728b1e2006-11-25 11:09:28 -0800271 "at91_rtc", pdev);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700272 if (ret) {
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700273 printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n",
274 AT91_ID_SYS);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700275 return ret;
276 }
277
David Brownell5d4675a2007-02-20 13:58:14 -0800278 /* cpu init code should really have flagged this device as
279 * being wake-capable; if it didn't, do that here.
280 */
281 if (!device_can_wakeup(&pdev->dev))
282 device_init_wakeup(&pdev->dev, 1);
283
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700284 rtc = rtc_device_register(pdev->name, &pdev->dev,
285 &at91_rtc_ops, THIS_MODULE);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700286 if (IS_ERR(rtc)) {
287 free_irq(AT91_ID_SYS, pdev);
288 return PTR_ERR(rtc);
289 }
290 platform_set_drvdata(pdev, rtc);
291
292 printk(KERN_INFO "AT91 Real Time Clock driver.\n");
293 return 0;
294}
295
296/*
297 * Disable and remove the RTC driver
298 */
David Brownell5d4675a2007-02-20 13:58:14 -0800299static int __exit at91_rtc_remove(struct platform_device *pdev)
Andrew Victor788b1fc2006-06-25 05:48:27 -0700300{
301 struct rtc_device *rtc = platform_get_drvdata(pdev);
302
303 /* Disable all interrupts */
Andrew Mortone7a8bb12006-06-25 05:48:27 -0700304 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
305 AT91_RTC_SECEV | AT91_RTC_TIMEV |
306 AT91_RTC_CALEV);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700307 free_irq(AT91_ID_SYS, pdev);
308
309 rtc_device_unregister(rtc);
310 platform_set_drvdata(pdev, NULL);
311
312 return 0;
313}
314
315#ifdef CONFIG_PM
316
317/* AT91RM9200 RTC Power management control */
318
David Brownell90b4d642006-09-30 23:28:17 -0700319static u32 at91_rtc_imr;
Andrew Victor788b1fc2006-06-25 05:48:27 -0700320
David Brownelldac94d92009-09-22 16:46:31 -0700321static int at91_rtc_suspend(struct device *dev)
Andrew Victor788b1fc2006-06-25 05:48:27 -0700322{
David Brownell90b4d642006-09-30 23:28:17 -0700323 /* this IRQ is shared with DBGU and other hardware which isn't
324 * necessarily doing PM like we are...
325 */
326 at91_rtc_imr = at91_sys_read(AT91_RTC_IMR)
327 & (AT91_RTC_ALARM|AT91_RTC_SECEV);
328 if (at91_rtc_imr) {
David Brownelldac94d92009-09-22 16:46:31 -0700329 if (device_may_wakeup(dev))
David Brownell90b4d642006-09-30 23:28:17 -0700330 enable_irq_wake(AT91_ID_SYS);
331 else
332 at91_sys_write(AT91_RTC_IDR, at91_rtc_imr);
333 }
Andrew Victor788b1fc2006-06-25 05:48:27 -0700334 return 0;
335}
336
David Brownelldac94d92009-09-22 16:46:31 -0700337static int at91_rtc_resume(struct device *dev)
Andrew Victor788b1fc2006-06-25 05:48:27 -0700338{
David Brownell90b4d642006-09-30 23:28:17 -0700339 if (at91_rtc_imr) {
David Brownelldac94d92009-09-22 16:46:31 -0700340 if (device_may_wakeup(dev))
David Brownell90b4d642006-09-30 23:28:17 -0700341 disable_irq_wake(AT91_ID_SYS);
342 else
343 at91_sys_write(AT91_RTC_IER, at91_rtc_imr);
344 }
Andrew Victor788b1fc2006-06-25 05:48:27 -0700345 return 0;
346}
David Brownelldac94d92009-09-22 16:46:31 -0700347
348static const struct dev_pm_ops at91_rtc_pm = {
349 .suspend = at91_rtc_suspend,
350 .resume = at91_rtc_resume,
351};
352
353#define at91_rtc_pm_ptr &at91_rtc_pm
354
Andrew Victor788b1fc2006-06-25 05:48:27 -0700355#else
David Brownelldac94d92009-09-22 16:46:31 -0700356#define at91_rtc_pm_ptr NULL
Andrew Victor788b1fc2006-06-25 05:48:27 -0700357#endif
358
359static struct platform_driver at91_rtc_driver = {
David Brownell5d4675a2007-02-20 13:58:14 -0800360 .remove = __exit_p(at91_rtc_remove),
Andrew Victor788b1fc2006-06-25 05:48:27 -0700361 .driver = {
362 .name = "at91_rtc",
363 .owner = THIS_MODULE,
David Brownelldac94d92009-09-22 16:46:31 -0700364 .pm = at91_rtc_pm_ptr,
Andrew Victor788b1fc2006-06-25 05:48:27 -0700365 },
366};
367
368static int __init at91_rtc_init(void)
369{
David Brownell5d4675a2007-02-20 13:58:14 -0800370 return platform_driver_probe(&at91_rtc_driver, at91_rtc_probe);
Andrew Victor788b1fc2006-06-25 05:48:27 -0700371}
372
373static void __exit at91_rtc_exit(void)
374{
375 platform_driver_unregister(&at91_rtc_driver);
376}
377
Andrew Victor788b1fc2006-06-25 05:48:27 -0700378module_init(at91_rtc_init);
379module_exit(at91_rtc_exit);
380
381MODULE_AUTHOR("Rick Bronson");
382MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
383MODULE_LICENSE("GPL");
Kay Sieversad28a072008-04-10 21:29:25 -0700384MODULE_ALIAS("platform:at91_rtc");