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Linux 2.6.34-rc3
[pohmelfs.git] / drivers / rtc / rtc-sa1100.c
blobe4a44b641702677ba99884f03089477f1c04f3cd
1 /*
2 * Real Time Clock interface for StrongARM SA1x00 and XScale PXA2xx
3 *
4 * Copyright (c) 2000 Nils Faerber
5 *
6 * Based on rtc.c by Paul Gortmaker
7 *
8 * Original Driver by Nils Faerber <nils@kernelconcepts.de>
9 *
10 * Modifications from:
11 * CIH <cih@coventive.com>
12 * Nicolas Pitre <nico@fluxnic.net>
13 * Andrew Christian <andrew.christian@hp.com>
14 *
15 * Converted to the RTC subsystem and Driver Model
16 * by Richard Purdie <rpurdie@rpsys.net>
17 *
18 * This program is free software; you can redistribute it and/or
19 * modify it under the terms of the GNU General Public License
20 * as published by the Free Software Foundation; either version
21 * 2 of the License, or (at your option) any later version.
22 */
23
24 #include <linux/platform_device.h>
25 #include <linux/module.h>
26 #include <linux/rtc.h>
27 #include <linux/init.h>
28 #include <linux/fs.h>
29 #include <linux/interrupt.h>
30 #include <linux/string.h>
31 #include <linux/pm.h>
32 #include <linux/bitops.h>
33
34 #include <mach/hardware.h>
35 #include <asm/irq.h>
36
37 #ifdef CONFIG_ARCH_PXA
38 #include <mach/regs-rtc.h>
39 #include <mach/regs-ost.h>
40 #endif
41
42 #define RTC_DEF_DIVIDER 32768 - 1
43 #define RTC_DEF_TRIM 0
44
45 static unsigned long rtc_freq = 1024;
46 static unsigned long timer_freq;
47 static struct rtc_time rtc_alarm;
48 static DEFINE_SPINLOCK(sa1100_rtc_lock);
49
50 static inline int rtc_periodic_alarm(struct rtc_time *tm)
51 {
52 return (tm->tm_year == -1) ||
53 ((unsigned)tm->tm_mon >= 12) ||
54 ((unsigned)(tm->tm_mday - 1) >= 31) ||
55 ((unsigned)tm->tm_hour > 23) ||
56 ((unsigned)tm->tm_min > 59) ||
57 ((unsigned)tm->tm_sec > 59);
58 }
59
60 /*
61 * Calculate the next alarm time given the requested alarm time mask
62 * and the current time.
63 */
64 static void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now, struct rtc_time *alrm)
65 {
66 unsigned long next_time;
67 unsigned long now_time;
68
69 next->tm_year = now->tm_year;
70 next->tm_mon = now->tm_mon;
71 next->tm_mday = now->tm_mday;
72 next->tm_hour = alrm->tm_hour;
73 next->tm_min = alrm->tm_min;
74 next->tm_sec = alrm->tm_sec;
75
76 rtc_tm_to_time(now, &now_time);
77 rtc_tm_to_time(next, &next_time);
78
79 if (next_time < now_time) {
80 /* Advance one day */
81 next_time += 60 * 60 * 24;
82 rtc_time_to_tm(next_time, next);
83 }
84 }
85
86 static int rtc_update_alarm(struct rtc_time *alrm)
87 {
88 struct rtc_time alarm_tm, now_tm;
89 unsigned long now, time;
90 int ret;
91
92 do {
93 now = RCNR;
94 rtc_time_to_tm(now, &now_tm);
95 rtc_next_alarm_time(&alarm_tm, &now_tm, alrm);
96 ret = rtc_tm_to_time(&alarm_tm, &time);
97 if (ret != 0)
98 break;
99
100 RTSR = RTSR & (RTSR_HZE|RTSR_ALE|RTSR_AL);
101 RTAR = time;
102 } while (now != RCNR);
103
104 return ret;
105 }
106
107 static irqreturn_t sa1100_rtc_interrupt(int irq, void *dev_id)
108 {
109 struct platform_device *pdev = to_platform_device(dev_id);
110 struct rtc_device *rtc = platform_get_drvdata(pdev);
111 unsigned int rtsr;
112 unsigned long events = 0;
113
114 spin_lock(&sa1100_rtc_lock);
115
116 rtsr = RTSR;
117 /* clear interrupt sources */
118 RTSR = 0;
119 RTSR = (RTSR_AL | RTSR_HZ) & (rtsr >> 2);
120
121 /* clear alarm interrupt if it has occurred */
122 if (rtsr & RTSR_AL)
123 rtsr &= ~RTSR_ALE;
124 RTSR = rtsr & (RTSR_ALE | RTSR_HZE);
125
126 /* update irq data & counter */
127 if (rtsr & RTSR_AL)
128 events |= RTC_AF | RTC_IRQF;
129 if (rtsr & RTSR_HZ)
130 events |= RTC_UF | RTC_IRQF;
131
132 rtc_update_irq(rtc, 1, events);
133
134 if (rtsr & RTSR_AL && rtc_periodic_alarm(&rtc_alarm))
135 rtc_update_alarm(&rtc_alarm);
136
137 spin_unlock(&sa1100_rtc_lock);
138
139 return IRQ_HANDLED;
140 }
141
142 static int rtc_timer1_count;
143
144 static irqreturn_t timer1_interrupt(int irq, void *dev_id)
145 {
146 struct platform_device *pdev = to_platform_device(dev_id);
147 struct rtc_device *rtc = platform_get_drvdata(pdev);
148
149 /*
150 * If we match for the first time, rtc_timer1_count will be 1.
151 * Otherwise, we wrapped around (very unlikely but
152 * still possible) so compute the amount of missed periods.
153 * The match reg is updated only when the data is actually retrieved
154 * to avoid unnecessary interrupts.
155 */
156 OSSR = OSSR_M1; /* clear match on timer1 */
157
158 rtc_update_irq(rtc, rtc_timer1_count, RTC_PF | RTC_IRQF);
159
160 if (rtc_timer1_count == 1)
161 rtc_timer1_count = (rtc_freq * ((1 << 30) / (timer_freq >> 2)));
162
163 return IRQ_HANDLED;
164 }
165
166 static int sa1100_rtc_read_callback(struct device *dev, int data)
167 {
168 if (data & RTC_PF) {
169 /* interpolate missed periods and set match for the next */
170 unsigned long period = timer_freq / rtc_freq;
171 unsigned long oscr = OSCR;
172 unsigned long osmr1 = OSMR1;
173 unsigned long missed = (oscr - osmr1)/period;
174 data += missed << 8;
175 OSSR = OSSR_M1; /* clear match on timer 1 */
176 OSMR1 = osmr1 + (missed + 1)*period;
177 /* Ensure we didn't miss another match in the mean time.
178 * Here we compare (match - OSCR) 8 instead of 0 --
179 * see comment in pxa_timer_interrupt() for explanation.
180 */
181 while( (signed long)((osmr1 = OSMR1) - OSCR) <= 8 ) {
182 data += 0x100;
183 OSSR = OSSR_M1; /* clear match on timer 1 */
184 OSMR1 = osmr1 + period;
185 }
186 }
187 return data;
188 }
189
190 static int sa1100_rtc_open(struct device *dev)
191 {
192 int ret;
193
194 ret = request_irq(IRQ_RTC1Hz, sa1100_rtc_interrupt, IRQF_DISABLED,
195 "rtc 1Hz", dev);
196 if (ret) {
197 dev_err(dev, "IRQ %d already in use.\n", IRQ_RTC1Hz);
198 goto fail_ui;
199 }
200 ret = request_irq(IRQ_RTCAlrm, sa1100_rtc_interrupt, IRQF_DISABLED,
201 "rtc Alrm", dev);
202 if (ret) {
203 dev_err(dev, "IRQ %d already in use.\n", IRQ_RTCAlrm);
204 goto fail_ai;
205 }
206 ret = request_irq(IRQ_OST1, timer1_interrupt, IRQF_DISABLED,
207 "rtc timer", dev);
208 if (ret) {
209 dev_err(dev, "IRQ %d already in use.\n", IRQ_OST1);
210 goto fail_pi;
211 }
212 return 0;
213
214 fail_pi:
215 free_irq(IRQ_RTCAlrm, dev);
216 fail_ai:
217 free_irq(IRQ_RTC1Hz, dev);
218 fail_ui:
219 return ret;
220 }
221
222 static void sa1100_rtc_release(struct device *dev)
223 {
224 spin_lock_irq(&sa1100_rtc_lock);
225 RTSR = 0;
226 OIER &= ~OIER_E1;
227 OSSR = OSSR_M1;
228 spin_unlock_irq(&sa1100_rtc_lock);
229
230 free_irq(IRQ_OST1, dev);
231 free_irq(IRQ_RTCAlrm, dev);
232 free_irq(IRQ_RTC1Hz, dev);
233 }
234
235
236 static int sa1100_rtc_ioctl(struct device *dev, unsigned int cmd,
237 unsigned long arg)
238 {
239 switch(cmd) {
240 case RTC_AIE_OFF:
241 spin_lock_irq(&sa1100_rtc_lock);
242 RTSR &= ~RTSR_ALE;
243 spin_unlock_irq(&sa1100_rtc_lock);
244 return 0;
245 case RTC_AIE_ON:
246 spin_lock_irq(&sa1100_rtc_lock);
247 RTSR |= RTSR_ALE;
248 spin_unlock_irq(&sa1100_rtc_lock);
249 return 0;
250 case RTC_UIE_OFF:
251 spin_lock_irq(&sa1100_rtc_lock);
252 RTSR &= ~RTSR_HZE;
253 spin_unlock_irq(&sa1100_rtc_lock);
254 return 0;
255 case RTC_UIE_ON:
256 spin_lock_irq(&sa1100_rtc_lock);
257 RTSR |= RTSR_HZE;
258 spin_unlock_irq(&sa1100_rtc_lock);
259 return 0;
260 case RTC_PIE_OFF:
261 spin_lock_irq(&sa1100_rtc_lock);
262 OIER &= ~OIER_E1;
263 spin_unlock_irq(&sa1100_rtc_lock);
264 return 0;
265 case RTC_PIE_ON:
266 spin_lock_irq(&sa1100_rtc_lock);
267 OSMR1 = timer_freq / rtc_freq + OSCR;
268 OIER |= OIER_E1;
269 rtc_timer1_count = 1;
270 spin_unlock_irq(&sa1100_rtc_lock);
271 return 0;
272 case RTC_IRQP_READ:
273 return put_user(rtc_freq, (unsigned long *)arg);
274 case RTC_IRQP_SET:
275 if (arg < 1 || arg > timer_freq)
276 return -EINVAL;
277 rtc_freq = arg;
278 return 0;
279 }
280 return -ENOIOCTLCMD;
281 }
282
283 static int sa1100_rtc_read_time(struct device *dev, struct rtc_time *tm)
284 {
285 rtc_time_to_tm(RCNR, tm);
286 return 0;
287 }
288
289 static int sa1100_rtc_set_time(struct device *dev, struct rtc_time *tm)
290 {
291 unsigned long time;
292 int ret;
293
294 ret = rtc_tm_to_time(tm, &time);
295 if (ret == 0)
296 RCNR = time;
297 return ret;
298 }
299
300 static int sa1100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
301 {
302 u32 rtsr;
303
304 memcpy(&alrm->time, &rtc_alarm, sizeof(struct rtc_time));
305 rtsr = RTSR;
306 alrm->enabled = (rtsr & RTSR_ALE) ? 1 : 0;
307 alrm->pending = (rtsr & RTSR_AL) ? 1 : 0;
308 return 0;
309 }
310
311 static int sa1100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
312 {
313 int ret;
314
315 spin_lock_irq(&sa1100_rtc_lock);
316 ret = rtc_update_alarm(&alrm->time);
317 if (ret == 0) {
318 if (alrm->enabled)
319 RTSR |= RTSR_ALE;
320 else
321 RTSR &= ~RTSR_ALE;
322 }
323 spin_unlock_irq(&sa1100_rtc_lock);
324
325 return ret;
326 }
327
328 static int sa1100_rtc_proc(struct device *dev, struct seq_file *seq)
329 {
330 seq_printf(seq, "trim/divider\t: 0x%08x\n", (u32) RTTR);
331 seq_printf(seq, "update_IRQ\t: %s\n",
332 (RTSR & RTSR_HZE) ? "yes" : "no");
333 seq_printf(seq, "periodic_IRQ\t: %s\n",
334 (OIER & OIER_E1) ? "yes" : "no");
335 seq_printf(seq, "periodic_freq\t: %ld\n", rtc_freq);
336
337 return 0;
338 }
339
340 static const struct rtc_class_ops sa1100_rtc_ops = {
341 .open = sa1100_rtc_open,
342 .read_callback = sa1100_rtc_read_callback,
343 .release = sa1100_rtc_release,
344 .ioctl = sa1100_rtc_ioctl,
345 .read_time = sa1100_rtc_read_time,
346 .set_time = sa1100_rtc_set_time,
347 .read_alarm = sa1100_rtc_read_alarm,
348 .set_alarm = sa1100_rtc_set_alarm,
349 .proc = sa1100_rtc_proc,
350 };
351
352 static int sa1100_rtc_probe(struct platform_device *pdev)
353 {
354 struct rtc_device *rtc;
355
356 timer_freq = get_clock_tick_rate();
357
358 /*
359 * According to the manual we should be able to let RTTR be zero
360 * and then a default diviser for a 32.768KHz clock is used.
361 * Apparently this doesn't work, at least for my SA1110 rev 5.
362 * If the clock divider is uninitialized then reset it to the
363 * default value to get the 1Hz clock.
364 */
365 if (RTTR == 0) {
366 RTTR = RTC_DEF_DIVIDER + (RTC_DEF_TRIM << 16);
367 dev_warn(&pdev->dev, "warning: initializing default clock divider/trim value\n");
368 /* The current RTC value probably doesn't make sense either */
369 RCNR = 0;
370 }
371
372 device_init_wakeup(&pdev->dev, 1);
373
374 rtc = rtc_device_register(pdev->name, &pdev->dev, &sa1100_rtc_ops,
375 THIS_MODULE);
376
377 if (IS_ERR(rtc))
378 return PTR_ERR(rtc);
379
380 platform_set_drvdata(pdev, rtc);
381
382 return 0;
383 }
384
385 static int sa1100_rtc_remove(struct platform_device *pdev)
386 {
387 struct rtc_device *rtc = platform_get_drvdata(pdev);
388
389 if (rtc)
390 rtc_device_unregister(rtc);
391
392 return 0;
393 }
394
395 #ifdef CONFIG_PM
396 static int sa1100_rtc_suspend(struct device *dev)
397 {
398 if (device_may_wakeup(dev))
399 enable_irq_wake(IRQ_RTCAlrm);
400 return 0;
401 }
402
403 static int sa1100_rtc_resume(struct device *dev)
404 {
405 if (device_may_wakeup(dev))
406 disable_irq_wake(IRQ_RTCAlrm);
407 return 0;
408 }
409
410 static const struct dev_pm_ops sa1100_rtc_pm_ops = {
411 .suspend = sa1100_rtc_suspend,
412 .resume = sa1100_rtc_resume,
413 };
414 #endif
415
416 static struct platform_driver sa1100_rtc_driver = {
417 .probe = sa1100_rtc_probe,
418 .remove = sa1100_rtc_remove,
419 .driver = {
420 .name = "sa1100-rtc",
421 #ifdef CONFIG_PM
422 .pm = &sa1100_rtc_pm_ops,
423 #endif
424 },
425 };
426
427 static int __init sa1100_rtc_init(void)
428 {
429 return platform_driver_register(&sa1100_rtc_driver);
430 }
431
432 static void __exit sa1100_rtc_exit(void)
433 {
434 platform_driver_unregister(&sa1100_rtc_driver);
435 }
436
437 module_init(sa1100_rtc_init);
438 module_exit(sa1100_rtc_exit);
439
440 MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
441 MODULE_DESCRIPTION("SA11x0/PXA2xx Realtime Clock Driver (RTC)");
442 MODULE_LICENSE("GPL");
443 MODULE_ALIAS("platform:sa1100-rtc");