37082616482bd7a79ad3162ba00ca82bd260894e
[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 wille 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 /*
187  * Handle commands from user-space
188  */
189 static int at91_rtc_ioctl(struct device *dev, unsigned int cmd,
190                         unsigned long arg)
191 {
192         int ret = 0;
193
194         pr_debug("%s(): cmd=%08x, arg=%08lx.\n", __func__, cmd, arg);
195
196         /* important:  scrub old status before enabling IRQs */
197         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 */
202                 at91_sys_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
203                 at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
204                 break;
205         case RTC_UIE_OFF:       /* update off */
206                 at91_sys_write(AT91_RTC_IDR, AT91_RTC_SECEV);
207                 break;
208         case RTC_UIE_ON:        /* update on */
209                 at91_sys_write(AT91_RTC_SCCR, AT91_RTC_SECEV);
210                 at91_sys_write(AT91_RTC_IER, AT91_RTC_SECEV);
211                 break;
212         default:
213                 ret = -ENOIOCTLCMD;
214                 break;
215         }
216
217         return ret;
218 }
219
220 /*
221  * Provide additional RTC information in /proc/driver/rtc
222  */
223 static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
224 {
225         unsigned long imr = at91_sys_read(AT91_RTC_IMR);
226
227         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
232         return 0;
233 }
234
235 /*
236  * IRQ handler for the RTC
237  */
238 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
239 {
240         struct platform_device *pdev = dev_id;
241         struct rtc_device *rtc = platform_get_drvdata(pdev);
242         unsigned int rtsr;
243         unsigned long events = 0;
244
245         rtsr = at91_sys_read(AT91_RTC_SR) & at91_sys_read(AT91_RTC_IMR);
246         if (rtsr) {             /* this interrupt is shared!  Is it ours? */
247                 if (rtsr & AT91_RTC_ALARM)
248                         events |= (RTC_AF | RTC_IRQF);
249                 if (rtsr & AT91_RTC_SECEV)
250                         events |= (RTC_UF | RTC_IRQF);
251                 if (rtsr & AT91_RTC_ACKUPD)
252                         complete(&at91_rtc_updated);
253
254                 at91_sys_write(AT91_RTC_SCCR, rtsr);    /* clear status reg */
255
256                 rtc_update_irq(rtc, 1, events);
257
258                 pr_debug("%s(): num=%ld, events=0x%02lx\n", __func__,
259                         events >> 8, events & 0x000000FF);
260
261                 return IRQ_HANDLED;
262         }
263         return IRQ_NONE;                /* not handled */
264 }
265
266 static const struct rtc_class_ops at91_rtc_ops = {
267         .ioctl          = at91_rtc_ioctl,
268         .read_time      = at91_rtc_readtime,
269         .set_time       = at91_rtc_settime,
270         .read_alarm     = at91_rtc_readalarm,
271         .set_alarm      = at91_rtc_setalarm,
272         .proc           = at91_rtc_proc,
273 };
274
275 /*
276  * Initialize and install RTC driver
277  */
278 static int __init at91_rtc_probe(struct platform_device *pdev)
279 {
280         struct rtc_device *rtc;
281         int ret;
282
283         at91_sys_write(AT91_RTC_CR, 0);
284         at91_sys_write(AT91_RTC_MR, 0);         /* 24 hour mode */
285
286         /* Disable all interrupts */
287         at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
288                                         AT91_RTC_SECEV | AT91_RTC_TIMEV |
289                                         AT91_RTC_CALEV);
290
291         ret = request_irq(AT91_ID_SYS, at91_rtc_interrupt,
292                                 IRQF_DISABLED | IRQF_SHARED,
293                                 "at91_rtc", pdev);
294         if (ret) {
295                 printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n",
296                                 AT91_ID_SYS);
297                 return ret;
298         }
299
300         /* cpu init code should really have flagged this device as
301          * being wake-capable; if it didn't, do that here.
302          */
303         if (!device_can_wakeup(&pdev->dev))
304                 device_init_wakeup(&pdev->dev, 1);
305
306         rtc = rtc_device_register(pdev->name, &pdev->dev,
307                                 &at91_rtc_ops, THIS_MODULE);
308         if (IS_ERR(rtc)) {
309                 free_irq(AT91_ID_SYS, pdev);
310                 return PTR_ERR(rtc);
311         }
312         platform_set_drvdata(pdev, rtc);
313
314         printk(KERN_INFO "AT91 Real Time Clock driver.\n");
315         return 0;
316 }
317
318 /*
319  * Disable and remove the RTC driver
320  */
321 static int __exit at91_rtc_remove(struct platform_device *pdev)
322 {
323         struct rtc_device *rtc = platform_get_drvdata(pdev);
324
325         /* Disable all interrupts */
326         at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
327                                         AT91_RTC_SECEV | AT91_RTC_TIMEV |
328                                         AT91_RTC_CALEV);
329         free_irq(AT91_ID_SYS, pdev);
330
331         rtc_device_unregister(rtc);
332         platform_set_drvdata(pdev, NULL);
333
334         return 0;
335 }
336
337 #ifdef CONFIG_PM
338
339 /* AT91RM9200 RTC Power management control */
340
341 static u32 at91_rtc_imr;
342
343 static int at91_rtc_suspend(struct platform_device *pdev, pm_message_t state)
344 {
345         /* this IRQ is shared with DBGU and other hardware which isn't
346          * necessarily doing PM like we are...
347          */
348         at91_rtc_imr = at91_sys_read(AT91_RTC_IMR)
349                         & (AT91_RTC_ALARM|AT91_RTC_SECEV);
350         if (at91_rtc_imr) {
351                 if (device_may_wakeup(&pdev->dev))
352                         enable_irq_wake(AT91_ID_SYS);
353                 else
354                         at91_sys_write(AT91_RTC_IDR, at91_rtc_imr);
355         }
356         return 0;
357 }
358
359 static int at91_rtc_resume(struct platform_device *pdev)
360 {
361         if (at91_rtc_imr) {
362                 if (device_may_wakeup(&pdev->dev))
363                         disable_irq_wake(AT91_ID_SYS);
364                 else
365                         at91_sys_write(AT91_RTC_IER, at91_rtc_imr);
366         }
367         return 0;
368 }
369 #else
370 #define at91_rtc_suspend NULL
371 #define at91_rtc_resume  NULL
372 #endif
373
374 static struct platform_driver at91_rtc_driver = {
375         .remove         = __exit_p(at91_rtc_remove),
376         .suspend        = at91_rtc_suspend,
377         .resume         = at91_rtc_resume,
378         .driver         = {
379                 .name   = "at91_rtc",
380                 .owner  = THIS_MODULE,
381         },
382 };
383
384 static int __init at91_rtc_init(void)
385 {
386         return platform_driver_probe(&at91_rtc_driver, at91_rtc_probe);
387 }
388
389 static void __exit at91_rtc_exit(void)
390 {
391         platform_driver_unregister(&at91_rtc_driver);
392 }
393
394 module_init(at91_rtc_init);
395 module_exit(at91_rtc_exit);
396
397 MODULE_AUTHOR("Rick Bronson");
398 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
399 MODULE_LICENSE("GPL");
400 MODULE_ALIAS("platform:at91_rtc");