e39b77a4609af46902dc71ec2f2c6c72b6426c0a
[linux-2.6.git] / drivers / rtc / rtc-at91rm9200.c
1 /*
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
33 #include <mach/at91_rtc.h>
34
35
36 #define AT91_RTC_EPOCH          1900UL  /* just like arch/arm/common/rtctime.c */
37
38 static DECLARE_COMPLETION(at91_rtc_updated);
39 static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
40
41 /*
42  * Decode time/date into rtc_time structure
43  */
44 static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
45                                 struct rtc_time *tm)
46 {
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);
53         } while ((time != at91_sys_read(timereg)) ||
54                         (date != at91_sys_read(calreg)));
55
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 will store the current year.
64          */
65         tm->tm_year  = bcd2bin(date & AT91_RTC_CENT) * 100;     /* century */
66         tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8);    /* year */
67
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  */
76 static 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
82         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
83                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
84                 tm->tm_hour, tm->tm_min, tm->tm_sec);
85
86         return 0;
87 }
88
89 /*
90  * Set current time and date in RTC
91  */
92 static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
93 {
94         unsigned long cr;
95
96         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
97                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
98                 tm->tm_hour, tm->tm_min, tm->tm_sec);
99
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);
105         wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
106         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,
114                           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);
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  */
130 static 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
138         alrm->enabled = (at91_sys_read(AT91_RTC_IMR) & AT91_RTC_ALARM)
139                         ? 1 : 0;
140
141         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
142                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
143                 tm->tm_hour, tm->tm_min, tm->tm_sec);
144
145         return 0;
146 }
147
148 /*
149  * Set alarm time and date in RTC
150  */
151 static 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
163         at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
164         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
174         if (alrm->enabled) {
175                 at91_sys_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
176                 at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
177         }
178
179         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
180                 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
181                 tm.tm_min, tm.tm_sec);
182
183         return 0;
184 }
185
186 static 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 }
198 /*
199  * Provide additional RTC information in /proc/driver/rtc
200  */
201 static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
202 {
203         unsigned long imr = at91_sys_read(AT91_RTC_IMR);
204
205         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");
209
210         return 0;
211 }
212
213 /*
214  * IRQ handler for the RTC
215  */
216 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
217 {
218         struct platform_device *pdev = dev_id;
219         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
232                 at91_sys_write(AT91_RTC_SCCR, rtsr);    /* clear status reg */
233
234                 rtc_update_irq(rtc, 1, events);
235
236                 pr_debug("%s(): num=%ld, events=0x%02lx\n", __func__,
237                         events >> 8, events & 0x000000FF);
238
239                 return IRQ_HANDLED;
240         }
241         return IRQ_NONE;                /* not handled */
242 }
243
244 static const struct rtc_class_ops at91_rtc_ops = {
245         .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,
250         .alarm_irq_enable = at91_rtc_alarm_irq_enable,
251 };
252
253 /*
254  * Initialize and install RTC driver
255  */
256 static 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 */
265         at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
266                                         AT91_RTC_SECEV | AT91_RTC_TIMEV |
267                                         AT91_RTC_CALEV);
268
269         ret = request_irq(AT91_ID_SYS, at91_rtc_interrupt,
270                                 IRQF_SHARED,
271                                 "at91_rtc", pdev);
272         if (ret) {
273                 printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n",
274                                 AT91_ID_SYS);
275                 return ret;
276         }
277
278         /* 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
284         rtc = rtc_device_register(pdev->name, &pdev->dev,
285                                 &at91_rtc_ops, THIS_MODULE);
286         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  */
299 static int __exit at91_rtc_remove(struct platform_device *pdev)
300 {
301         struct rtc_device *rtc = platform_get_drvdata(pdev);
302
303         /* Disable all interrupts */
304         at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
305                                         AT91_RTC_SECEV | AT91_RTC_TIMEV |
306                                         AT91_RTC_CALEV);
307         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
319 static u32 at91_rtc_imr;
320
321 static int at91_rtc_suspend(struct device *dev)
322 {
323         /* 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) {
329                 if (device_may_wakeup(dev))
330                         enable_irq_wake(AT91_ID_SYS);
331                 else
332                         at91_sys_write(AT91_RTC_IDR, at91_rtc_imr);
333         }
334         return 0;
335 }
336
337 static int at91_rtc_resume(struct device *dev)
338 {
339         if (at91_rtc_imr) {
340                 if (device_may_wakeup(dev))
341                         disable_irq_wake(AT91_ID_SYS);
342                 else
343                         at91_sys_write(AT91_RTC_IER, at91_rtc_imr);
344         }
345         return 0;
346 }
347
348 static 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
355 #else
356 #define at91_rtc_pm_ptr NULL
357 #endif
358
359 static struct platform_driver at91_rtc_driver = {
360         .remove         = __exit_p(at91_rtc_remove),
361         .driver         = {
362                 .name   = "at91_rtc",
363                 .owner  = THIS_MODULE,
364                 .pm     = at91_rtc_pm_ptr,
365         },
366 };
367
368 static int __init at91_rtc_init(void)
369 {
370         return platform_driver_probe(&at91_rtc_driver, at91_rtc_probe);
371 }
372
373 static void __exit at91_rtc_exit(void)
374 {
375         platform_driver_unregister(&at91_rtc_driver);
376 }
377
378 module_init(at91_rtc_init);
379 module_exit(at91_rtc_exit);
380
381 MODULE_AUTHOR("Rick Bronson");
382 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
383 MODULE_LICENSE("GPL");
384 MODULE_ALIAS("platform:at91_rtc");