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autofs4: fix sparse warning in root.c
[linux-2.6/kmemtrace.git] / drivers / rtc / rtc-at91rm9200.c
blob39e64ab1ecb71b139c336fae6ba4bb637ea61ffb
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 #include <asm/rtc.h>
33
34 #include <asm/mach/time.h>
35
36 #include <asm/arch/at91_rtc.h>
37
38
39 #define AT91_RTC_FREQ 1
40 #define AT91_RTC_EPOCH 1900UL /* just like arch/arm/common/rtctime.c */
41
42 static DECLARE_COMPLETION(at91_rtc_updated);
43 static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
44
45 /*
46 * Decode time/date into rtc_time structure
47 */
48 static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
49 struct rtc_time *tm)
50 {
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);
57 } while ((time != at91_sys_read(timereg)) ||
58 (date != at91_sys_read(calreg)));
59
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 */
69 tm->tm_year = BCD2BIN(date & AT91_RTC_CENT) * 100; /* century */
70 tm->tm_year += BCD2BIN((date & AT91_RTC_YEAR) >> 8); /* year */
71
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 */
80 static 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", __func__,
87 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
88 tm->tm_hour, tm->tm_min, tm->tm_sec);
89
90 return 0;
91 }
92
93 /*
94 * Set current time and date in RTC
95 */
96 static 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", __func__,
101 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
102 tm->tm_hour, tm->tm_min, tm->tm_sec);
103
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);
109 wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
110 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,
118 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 */
122 | 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 */
134 static 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
142 alrm->enabled = (at91_sys_read(AT91_RTC_IMR) & AT91_RTC_ALARM)
143 ? 1 : 0;
144
145 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
146 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
147 tm->tm_hour, tm->tm_min, tm->tm_sec);
148
149 return 0;
150 }
151
152 /*
153 * Set alarm time and date in RTC
154 */
155 static 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_IDR, AT91_RTC_ALARM);
168 at91_sys_write(AT91_RTC_TIMALR,
169 BIN2BCD(tm.tm_sec) << 0
170 | BIN2BCD(tm.tm_min) << 8
171 | BIN2BCD(tm.tm_hour) << 16
172 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
173 at91_sys_write(AT91_RTC_CALALR,
174 BIN2BCD(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */
175 | BIN2BCD(tm.tm_mday) << 24
176 | AT91_RTC_DATEEN | AT91_RTC_MTHEN);
177
178 if (alrm->enabled)
179 at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
180
181 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
182 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
183 tm.tm_min, tm.tm_sec);
184
185 return 0;
186 }
187
188 /*
189 * Handle commands from user-space
190 */
191 static int at91_rtc_ioctl(struct device *dev, unsigned int cmd,
192 unsigned long arg)
193 {
194 int ret = 0;
195
196 pr_debug("%s(): cmd=%08x, arg=%08lx.\n", __func__, cmd, arg);
197
198 switch (cmd) {
199 case RTC_AIE_OFF: /* alarm off */
200 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
201 break;
202 case RTC_AIE_ON: /* alarm on */
203 at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
204 break;
205 case RTC_UIE_OFF: /* update off */
206 case RTC_PIE_OFF: /* periodic off */
207 at91_sys_write(AT91_RTC_IDR, AT91_RTC_SECEV);
208 break;
209 case RTC_UIE_ON: /* update on */
210 case RTC_PIE_ON: /* periodic on */
211 at91_sys_write(AT91_RTC_IER, AT91_RTC_SECEV);
212 break;
213 case RTC_IRQP_READ: /* read periodic alarm frequency */
214 ret = put_user(AT91_RTC_FREQ, (unsigned long *) arg);
215 break;
216 case RTC_IRQP_SET: /* set periodic alarm frequency */
217 if (arg != AT91_RTC_FREQ)
218 ret = -EINVAL;
219 break;
220 default:
221 ret = -ENOIOCTLCMD;
222 break;
223 }
224
225 return ret;
226 }
227
228 /*
229 * Provide additional RTC information in /proc/driver/rtc
230 */
231 static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
232 {
233 unsigned long imr = at91_sys_read(AT91_RTC_IMR);
234
235 seq_printf(seq, "update_IRQ\t: %s\n",
236 (imr & AT91_RTC_ACKUPD) ? "yes" : "no");
237 seq_printf(seq, "periodic_IRQ\t: %s\n",
238 (imr & AT91_RTC_SECEV) ? "yes" : "no");
239 seq_printf(seq, "periodic_freq\t: %ld\n",
240 (unsigned long) AT91_RTC_FREQ);
241
242 return 0;
243 }
244
245 /*
246 * IRQ handler for the RTC
247 */
248 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
249 {
250 struct platform_device *pdev = dev_id;
251 struct rtc_device *rtc = platform_get_drvdata(pdev);
252 unsigned int rtsr;
253 unsigned long events = 0;
254
255 rtsr = at91_sys_read(AT91_RTC_SR) & at91_sys_read(AT91_RTC_IMR);
256 if (rtsr) { /* this interrupt is shared! Is it ours? */
257 if (rtsr & AT91_RTC_ALARM)
258 events |= (RTC_AF | RTC_IRQF);
259 if (rtsr & AT91_RTC_SECEV)
260 events |= (RTC_UF | RTC_IRQF);
261 if (rtsr & AT91_RTC_ACKUPD)
262 complete(&at91_rtc_updated);
263
264 at91_sys_write(AT91_RTC_SCCR, rtsr); /* clear status reg */
265
266 rtc_update_irq(rtc, 1, events);
267
268 pr_debug("%s(): num=%ld, events=0x%02lx\n", __func__,
269 events >> 8, events & 0x000000FF);
270
271 return IRQ_HANDLED;
272 }
273 return IRQ_NONE; /* not handled */
274 }
275
276 static const struct rtc_class_ops at91_rtc_ops = {
277 .ioctl = at91_rtc_ioctl,
278 .read_time = at91_rtc_readtime,
279 .set_time = at91_rtc_settime,
280 .read_alarm = at91_rtc_readalarm,
281 .set_alarm = at91_rtc_setalarm,
282 .proc = at91_rtc_proc,
283 };
284
285 /*
286 * Initialize and install RTC driver
287 */
288 static int __init at91_rtc_probe(struct platform_device *pdev)
289 {
290 struct rtc_device *rtc;
291 int ret;
292
293 at91_sys_write(AT91_RTC_CR, 0);
294 at91_sys_write(AT91_RTC_MR, 0); /* 24 hour mode */
295
296 /* Disable all interrupts */
297 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
298 AT91_RTC_SECEV | AT91_RTC_TIMEV |
299 AT91_RTC_CALEV);
300
301 ret = request_irq(AT91_ID_SYS, at91_rtc_interrupt,
302 IRQF_DISABLED | IRQF_SHARED,
303 "at91_rtc", pdev);
304 if (ret) {
305 printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n",
306 AT91_ID_SYS);
307 return ret;
308 }
309
310 /* cpu init code should really have flagged this device as
311 * being wake-capable; if it didn't, do that here.
312 */
313 if (!device_can_wakeup(&pdev->dev))
314 device_init_wakeup(&pdev->dev, 1);
315
316 rtc = rtc_device_register(pdev->name, &pdev->dev,
317 &at91_rtc_ops, THIS_MODULE);
318 if (IS_ERR(rtc)) {
319 free_irq(AT91_ID_SYS, pdev);
320 return PTR_ERR(rtc);
321 }
322 platform_set_drvdata(pdev, rtc);
323
324 printk(KERN_INFO "AT91 Real Time Clock driver.\n");
325 return 0;
326 }
327
328 /*
329 * Disable and remove the RTC driver
330 */
331 static int __exit at91_rtc_remove(struct platform_device *pdev)
332 {
333 struct rtc_device *rtc = platform_get_drvdata(pdev);
334
335 /* Disable all interrupts */
336 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
337 AT91_RTC_SECEV | AT91_RTC_TIMEV |
338 AT91_RTC_CALEV);
339 free_irq(AT91_ID_SYS, pdev);
340
341 rtc_device_unregister(rtc);
342 platform_set_drvdata(pdev, NULL);
343
344 return 0;
345 }
346
347 #ifdef CONFIG_PM
348
349 /* AT91RM9200 RTC Power management control */
350
351 static u32 at91_rtc_imr;
352
353 static int at91_rtc_suspend(struct platform_device *pdev, pm_message_t state)
354 {
355 /* this IRQ is shared with DBGU and other hardware which isn't
356 * necessarily doing PM like we are...
357 */
358 at91_rtc_imr = at91_sys_read(AT91_RTC_IMR)
359 & (AT91_RTC_ALARM|AT91_RTC_SECEV);
360 if (at91_rtc_imr) {
361 if (device_may_wakeup(&pdev->dev))
362 enable_irq_wake(AT91_ID_SYS);
363 else
364 at91_sys_write(AT91_RTC_IDR, at91_rtc_imr);
365 }
366 return 0;
367 }
368
369 static int at91_rtc_resume(struct platform_device *pdev)
370 {
371 if (at91_rtc_imr) {
372 if (device_may_wakeup(&pdev->dev))
373 disable_irq_wake(AT91_ID_SYS);
374 else
375 at91_sys_write(AT91_RTC_IER, at91_rtc_imr);
376 }
377 return 0;
378 }
379 #else
380 #define at91_rtc_suspend NULL
381 #define at91_rtc_resume NULL
382 #endif
383
384 static struct platform_driver at91_rtc_driver = {
385 .remove = __exit_p(at91_rtc_remove),
386 .suspend = at91_rtc_suspend,
387 .resume = at91_rtc_resume,
388 .driver = {
389 .name = "at91_rtc",
390 .owner = THIS_MODULE,
391 },
392 };
393
394 static int __init at91_rtc_init(void)
395 {
396 return platform_driver_probe(&at91_rtc_driver, at91_rtc_probe);
397 }
398
399 static void __exit at91_rtc_exit(void)
400 {
401 platform_driver_unregister(&at91_rtc_driver);
402 }
403
404 module_init(at91_rtc_init);
405 module_exit(at91_rtc_exit);
406
407 MODULE_AUTHOR("Rick Bronson");
408 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
409 MODULE_LICENSE("GPL");
410 MODULE_ALIAS("platform:at91_rtc");
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