tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
37#define AT91_RTC_FREQ 1
38#define AT91_RTC_EPOCH 1900UL /* just like arch/arm/common/rtctime.c */
39
40static DECLARE_COMPLETION(at91_rtc_updated);
41static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
42
43/*
44 * Decode time/date into rtc_time structure
45 */
46static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
47 struct rtc_time *tm)
48{
49 unsigned int time, date;
50
51 /* must read twice in case it changes */
52 do {
53 time = at91_sys_read(timereg);
54 date = at91_sys_read(calreg);
55 } while ((time != at91_sys_read(timereg)) ||
56 (date != at91_sys_read(calreg)));
57
58 tm->tm_sec = BCD2BIN((time & AT91_RTC_SEC) >> 0);
59 tm->tm_min = BCD2BIN((time & AT91_RTC_MIN) >> 8);
60 tm->tm_hour = BCD2BIN((time & AT91_RTC_HOUR) >> 16);
61
62 /*
63 * The Calendar Alarm register does not have a field for
64 * the year - so these will return an invalid value. When an
65 * alarm is set, at91_alarm_year wille store the current year.
66 */
67 tm->tm_year = BCD2BIN(date & AT91_RTC_CENT) * 100; /* century */
68 tm->tm_year += BCD2BIN((date & AT91_RTC_YEAR) >> 8); /* year */
69
70 tm->tm_wday = BCD2BIN((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */
71 tm->tm_mon = BCD2BIN((date & AT91_RTC_MONTH) >> 16) - 1;
72 tm->tm_mday = BCD2BIN((date & AT91_RTC_DATE) >> 24);
73}
74
75/*
76 * Read current time and date in RTC
77 */
78static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
79{
80 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
81 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
82 tm->tm_year = tm->tm_year - 1900;
83
84 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
85 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
86 tm->tm_hour, tm->tm_min, tm->tm_sec);
87
88 return 0;
89}
90
91/*
92 * Set current time and date in RTC
93 */
94static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
95{
96 unsigned long cr;
97
98 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
99 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
100 tm->tm_hour, tm->tm_min, tm->tm_sec);
101
102 /* Stop Time/Calendar from counting */
103 cr = at91_sys_read(AT91_RTC_CR);
104 at91_sys_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
105
106 at91_sys_write(AT91_RTC_IER, AT91_RTC_ACKUPD);
107 wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
108 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD);
109
110 at91_sys_write(AT91_RTC_TIMR,
111 BIN2BCD(tm->tm_sec) << 0
112 | BIN2BCD(tm->tm_min) << 8
113 | BIN2BCD(tm->tm_hour) << 16);
114
115 at91_sys_write(AT91_RTC_CALR,
116 BIN2BCD((tm->tm_year + 1900) / 100) /* century */
117 | BIN2BCD(tm->tm_year % 100) << 8 /* year */
118 | BIN2BCD(tm->tm_mon + 1) << 16 /* tm_mon starts at zero */
119 | BIN2BCD(tm->tm_wday + 1) << 21 /* day of the week [0-6], Sunday=0 */
120 | BIN2BCD(tm->tm_mday) << 24);
121
122 /* Restart Time/Calendar */
123 cr = at91_sys_read(AT91_RTC_CR);
124 at91_sys_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
125
126 return 0;
127}
128
129/*
130 * Read alarm time and date in RTC
131 */
132static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
133{
134 struct rtc_time *tm = &alrm->time;
135
136 at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
137 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
138 tm->tm_year = at91_alarm_year - 1900;
139
140 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
141 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
142 tm->tm_hour, tm->tm_min, tm->tm_sec);
143
144 return 0;
145}
146
147/*
148 * Set alarm time and date in RTC
149 */
150static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
151{
152 struct rtc_time tm;
153
154 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm);
155
156 at91_alarm_year = tm.tm_year;
157
158 tm.tm_hour = alrm->time.tm_hour;
159 tm.tm_min = alrm->time.tm_min;
160 tm.tm_sec = alrm->time.tm_sec;
161
162 at91_sys_write(AT91_RTC_TIMALR,
163 BIN2BCD(tm.tm_sec) << 0
164 | BIN2BCD(tm.tm_min) << 8
165 | BIN2BCD(tm.tm_hour) << 16
166 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
167 at91_sys_write(AT91_RTC_CALALR,
168 BIN2BCD(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */
169 | BIN2BCD(tm.tm_mday) << 24
170 | AT91_RTC_DATEEN | AT91_RTC_MTHEN);
171
172 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
173 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
174 tm.tm_min, tm.tm_sec);
175
176 return 0;
177}
178
179/*
180 * Handle commands from user-space
181 */
182static int at91_rtc_ioctl(struct device *dev, unsigned int cmd,
183 unsigned long arg)
184{
185 int ret = 0;
186
187 pr_debug("%s(): cmd=%08x, arg=%08lx.\n", __FUNCTION__, cmd, arg);
188
189 switch (cmd) {
190 case RTC_AIE_OFF: /* alarm off */
191 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
192 break;
193 case RTC_AIE_ON: /* alarm on */
194 at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
195 break;
196 case RTC_UIE_OFF: /* update off */
197 case RTC_PIE_OFF: /* periodic off */
198 at91_sys_write(AT91_RTC_IDR, AT91_RTC_SECEV);
199 break;
200 case RTC_UIE_ON: /* update on */
201 case RTC_PIE_ON: /* periodic on */
202 at91_sys_write(AT91_RTC_IER, AT91_RTC_SECEV);
203 break;
204 case RTC_IRQP_READ: /* read periodic alarm frequency */
205 ret = put_user(AT91_RTC_FREQ, (unsigned long *) arg);
206 break;
207 case RTC_IRQP_SET: /* set periodic alarm frequency */
208 if (arg != AT91_RTC_FREQ)
209 ret = -EINVAL;
210 break;
211 default:
212 ret = -ENOIOCTLCMD;
213 break;
214 }
215
216 return ret;
217}
218
219/*
220 * Provide additional RTC information in /proc/driver/rtc
221 */
222static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
223{
224 unsigned long imr = at91_sys_read(AT91_RTC_IMR);
225
226 seq_printf(seq, "alarm_IRQ\t: %s\n",
227 (imr & AT91_RTC_ALARM) ? "yes" : "no");
228 seq_printf(seq, "update_IRQ\t: %s\n",
229 (imr & AT91_RTC_ACKUPD) ? "yes" : "no");
230 seq_printf(seq, "periodic_IRQ\t: %s\n",
231 (imr & AT91_RTC_SECEV) ? "yes" : "no");
232 seq_printf(seq, "periodic_freq\t: %ld\n",
233 (unsigned long) AT91_RTC_FREQ);
234
235 return 0;
236}
237
238/*
239 * IRQ handler for the RTC
240 */
241static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
242{
243 struct platform_device *pdev = dev_id;
244 struct rtc_device *rtc = platform_get_drvdata(pdev);
245 unsigned int rtsr;
246 unsigned long events = 0;
247
248 rtsr = at91_sys_read(AT91_RTC_SR) & at91_sys_read(AT91_RTC_IMR);
249 if (rtsr) { /* this interrupt is shared! Is it ours? */
250 if (rtsr & AT91_RTC_ALARM)
251 events |= (RTC_AF | RTC_IRQF);
252 if (rtsr & AT91_RTC_SECEV)
253 events |= (RTC_UF | RTC_IRQF);
254 if (rtsr & AT91_RTC_ACKUPD)
255 complete(&at91_rtc_updated);
256
257 at91_sys_write(AT91_RTC_SCCR, rtsr); /* clear status reg */
258
259 rtc_update_irq(&rtc->class_dev, 1, events);
260
261 pr_debug("%s(): num=%ld, events=0x%02lx\n", __FUNCTION__,
262 events >> 8, events & 0x000000FF);
263
264 return IRQ_HANDLED;
265 }
266 return IRQ_NONE; /* not handled */
267}
268
269static const struct rtc_class_ops at91_rtc_ops = {
270 .ioctl = at91_rtc_ioctl,
271 .read_time = at91_rtc_readtime,
272 .set_time = at91_rtc_settime,
273 .read_alarm = at91_rtc_readalarm,
274 .set_alarm = at91_rtc_setalarm,
275 .proc = at91_rtc_proc,
276};
277
278/*
279 * Initialize and install RTC driver
280 */
281static int __init at91_rtc_probe(struct platform_device *pdev)
282{
283 struct rtc_device *rtc;
284 int ret;
285
286 at91_sys_write(AT91_RTC_CR, 0);
287 at91_sys_write(AT91_RTC_MR, 0); /* 24 hour mode */
288
289 /* Disable all interrupts */
290 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
291 AT91_RTC_SECEV | AT91_RTC_TIMEV |
292 AT91_RTC_CALEV);
293
294 ret = request_irq(AT91_ID_SYS, at91_rtc_interrupt,
295 IRQF_SHARED, "at91_rtc", pdev);
296 if (ret) {
297 printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n",
298 AT91_ID_SYS);
299 return ret;
300 }
301
302 rtc = rtc_device_register(pdev->name, &pdev->dev,
303 &at91_rtc_ops, THIS_MODULE);
304 if (IS_ERR(rtc)) {
305 free_irq(AT91_ID_SYS, pdev);
306 return PTR_ERR(rtc);
307 }
308 platform_set_drvdata(pdev, rtc);
309 device_init_wakeup(&pdev->dev, 1);
310
311 printk(KERN_INFO "AT91 Real Time Clock driver.\n");
312 return 0;
313}
314
315/*
316 * Disable and remove the RTC driver
317 */
318static int __devexit at91_rtc_remove(struct platform_device *pdev)
319{
320 struct rtc_device *rtc = platform_get_drvdata(pdev);
321
322 /* Disable all interrupts */
323 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
324 AT91_RTC_SECEV | AT91_RTC_TIMEV |
325 AT91_RTC_CALEV);
326 free_irq(AT91_ID_SYS, pdev);
327
328 rtc_device_unregister(rtc);
329 platform_set_drvdata(pdev, NULL);
330 device_init_wakeup(&pdev->dev, 0);
331
332 return 0;
333}
334
335#ifdef CONFIG_PM
336
337/* AT91RM9200 RTC Power management control */
338
339static struct timespec at91_rtc_delta;
340static u32 at91_rtc_imr;
341
342static int at91_rtc_suspend(struct platform_device *pdev, pm_message_t state)
343{
344 struct rtc_time tm;
345 struct timespec time;
346
347 time.tv_nsec = 0;
348
349 /* calculate time delta for suspend */
350 at91_rtc_readtime(&pdev->dev, &tm);
351 rtc_tm_to_time(&tm, &time.tv_sec);
352 save_time_delta(&at91_rtc_delta, &time);
353
354 /* this IRQ is shared with DBGU and other hardware which isn't
355 * necessarily doing PM like we are...
356 */
357 at91_rtc_imr = at91_sys_read(AT91_RTC_IMR)
358 & (AT91_RTC_ALARM|AT91_RTC_SECEV);
359 if (at91_rtc_imr) {
360 if (device_may_wakeup(&pdev->dev))
361 enable_irq_wake(AT91_ID_SYS);
362 else
363 at91_sys_write(AT91_RTC_IDR, at91_rtc_imr);
364 }
365
366 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
367 1900 + tm.tm_year, tm.tm_mon, tm.tm_mday,
368 tm.tm_hour, tm.tm_min, tm.tm_sec);
369
370 return 0;
371}
372
373static int at91_rtc_resume(struct platform_device *pdev)
374{
375 struct rtc_time tm;
376 struct timespec time;
377
378 time.tv_nsec = 0;
379
380 at91_rtc_readtime(&pdev->dev, &tm);
381 rtc_tm_to_time(&tm, &time.tv_sec);
382 restore_time_delta(&at91_rtc_delta, &time);
383
384 if (at91_rtc_imr) {
385 if (device_may_wakeup(&pdev->dev))
386 disable_irq_wake(AT91_ID_SYS);
387 else
388 at91_sys_write(AT91_RTC_IER, at91_rtc_imr);
389 }
390
391 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
392 1900 + tm.tm_year, tm.tm_mon, tm.tm_mday,
393 tm.tm_hour, tm.tm_min, tm.tm_sec);
394
395 return 0;
396}
397#else
398#define at91_rtc_suspend NULL
399#define at91_rtc_resume NULL
400#endif
401
402static struct platform_driver at91_rtc_driver = {
403 .probe = at91_rtc_probe,
404 .remove = at91_rtc_remove,
405 .suspend = at91_rtc_suspend,
406 .resume = at91_rtc_resume,
407 .driver = {
408 .name = "at91_rtc",
409 .owner = THIS_MODULE,
410 },
411};
412
413static int __init at91_rtc_init(void)
414{
415 return platform_driver_register(&at91_rtc_driver);
416}
417
418static void __exit at91_rtc_exit(void)
419{
420 platform_driver_unregister(&at91_rtc_driver);
421}
422
423module_init(at91_rtc_init);
424module_exit(at91_rtc_exit);
425
426MODULE_AUTHOR("Rick Bronson");
427MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
428MODULE_LICENSE("GPL");