blob: cb9a585312cc765c3e08a6d60720c3f669c8ba7b [file] [log] [blame]
Richard Purdiee842f1c2006-03-27 01:16:46 -08001/*
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>
Nicolas Pitre2f82af02009-09-14 03:25:28 -040012 * Nicolas Pitre <nico@fluxnic.net>
Richard Purdiee842f1c2006-03-27 01:16:46 -080013 * 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>
Russell Kinga0164a52012-01-19 11:55:21 +000030#include <linux/string.h>
Richard Purdiee842f1c2006-03-27 01:16:46 -080031#include <linux/pm.h>
Russell Kinga0164a52012-01-19 11:55:21 +000032#include <linux/bitops.h>
Richard Purdiee842f1c2006-03-27 01:16:46 -080033
Russell Kinga09e64f2008-08-05 16:14:15 +010034#include <mach/hardware.h>
Richard Purdiee842f1c2006-03-27 01:16:46 -080035#include <asm/irq.h>
Richard Purdiee842f1c2006-03-27 01:16:46 -080036
Russell Kinga0164a52012-01-19 11:55:21 +000037#ifdef CONFIG_ARCH_PXA
38#include <mach/regs-rtc.h>
39#endif
40
Marcelo Roberto Jimeneza404ad12010-10-18 22:33:53 +010041#define RTC_DEF_DIVIDER (32768 - 1)
Richard Purdiee842f1c2006-03-27 01:16:46 -080042#define RTC_DEF_TRIM 0
43
Russell Kinga0164a52012-01-19 11:55:21 +000044static const unsigned long RTC_FREQ = 1024;
45static struct rtc_time rtc_alarm;
46static DEFINE_SPINLOCK(sa1100_rtc_lock);
Richard Purdiee842f1c2006-03-27 01:16:46 -080047
Russell King57270fc2012-01-19 11:50:40 +000048static inline int rtc_periodic_alarm(struct rtc_time *tm)
49{
50 return (tm->tm_year == -1) ||
51 ((unsigned)tm->tm_mon >= 12) ||
52 ((unsigned)(tm->tm_mday - 1) >= 31) ||
53 ((unsigned)tm->tm_hour > 23) ||
54 ((unsigned)tm->tm_min > 59) ||
55 ((unsigned)tm->tm_sec > 59);
56}
57
Russell King797276e2008-04-20 12:30:41 +010058/*
59 * Calculate the next alarm time given the requested alarm time mask
60 * and the current time.
61 */
Marcelo Roberto Jimeneza404ad12010-10-18 22:33:53 +010062static void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now,
63 struct rtc_time *alrm)
Russell King797276e2008-04-20 12:30:41 +010064{
65 unsigned long next_time;
66 unsigned long now_time;
67
68 next->tm_year = now->tm_year;
69 next->tm_mon = now->tm_mon;
70 next->tm_mday = now->tm_mday;
71 next->tm_hour = alrm->tm_hour;
72 next->tm_min = alrm->tm_min;
73 next->tm_sec = alrm->tm_sec;
74
75 rtc_tm_to_time(now, &now_time);
76 rtc_tm_to_time(next, &next_time);
77
78 if (next_time < now_time) {
79 /* Advance one day */
80 next_time += 60 * 60 * 24;
81 rtc_time_to_tm(next_time, next);
82 }
83}
84
Russell King57270fc2012-01-19 11:50:40 +000085static int rtc_update_alarm(struct rtc_time *alrm)
86{
87 struct rtc_time alarm_tm, now_tm;
88 unsigned long now, time;
89 int ret;
90
91 do {
92 now = RCNR;
93 rtc_time_to_tm(now, &now_tm);
94 rtc_next_alarm_time(&alarm_tm, &now_tm, alrm);
95 ret = rtc_tm_to_time(&alarm_tm, &time);
96 if (ret != 0)
97 break;
98
99 RTSR = RTSR & (RTSR_HZE|RTSR_ALE|RTSR_AL);
100 RTAR = time;
101 } while (now != RCNR);
102
103 return ret;
104}
105
David Howells7d12e782006-10-05 14:55:46 +0100106static irqreturn_t sa1100_rtc_interrupt(int irq, void *dev_id)
Richard Purdiee842f1c2006-03-27 01:16:46 -0800107{
108 struct platform_device *pdev = to_platform_device(dev_id);
Russell Kinga0164a52012-01-19 11:55:21 +0000109 struct rtc_device *rtc = platform_get_drvdata(pdev);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800110 unsigned int rtsr;
111 unsigned long events = 0;
112
Russell Kinga0164a52012-01-19 11:55:21 +0000113 spin_lock(&sa1100_rtc_lock);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800114
Russell Kinga0164a52012-01-19 11:55:21 +0000115 rtsr = RTSR;
Richard Purdiee842f1c2006-03-27 01:16:46 -0800116 /* clear interrupt sources */
Russell Kinga0164a52012-01-19 11:55:21 +0000117 RTSR = 0;
Marcelo Roberto Jimenez7decaa52010-10-18 22:35:54 +0100118 /* Fix for a nasty initialization problem the in SA11xx RTSR register.
119 * See also the comments in sa1100_rtc_probe(). */
120 if (rtsr & (RTSR_ALE | RTSR_HZE)) {
121 /* This is the original code, before there was the if test
122 * above. This code does not clear interrupts that were not
123 * enabled. */
Russell Kinga0164a52012-01-19 11:55:21 +0000124 RTSR = (RTSR_AL | RTSR_HZ) & (rtsr >> 2);
Marcelo Roberto Jimenez7decaa52010-10-18 22:35:54 +0100125 } else {
126 /* For some reason, it is possible to enter this routine
127 * without interruptions enabled, it has been tested with
128 * several units (Bug in SA11xx chip?).
129 *
130 * This situation leads to an infinite "loop" of interrupt
131 * routine calling and as a result the processor seems to
132 * lock on its first call to open(). */
Russell Kinga0164a52012-01-19 11:55:21 +0000133 RTSR = RTSR_AL | RTSR_HZ;
Marcelo Roberto Jimenez7decaa52010-10-18 22:35:54 +0100134 }
Richard Purdiee842f1c2006-03-27 01:16:46 -0800135
136 /* clear alarm interrupt if it has occurred */
137 if (rtsr & RTSR_AL)
138 rtsr &= ~RTSR_ALE;
Russell Kinga0164a52012-01-19 11:55:21 +0000139 RTSR = rtsr & (RTSR_ALE | RTSR_HZE);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800140
141 /* update irq data & counter */
142 if (rtsr & RTSR_AL)
143 events |= RTC_AF | RTC_IRQF;
144 if (rtsr & RTSR_HZ)
145 events |= RTC_UF | RTC_IRQF;
146
Russell Kinga0164a52012-01-19 11:55:21 +0000147 rtc_update_irq(rtc, 1, events);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800148
Russell King57270fc2012-01-19 11:50:40 +0000149 if (rtsr & RTSR_AL && rtc_periodic_alarm(&rtc_alarm))
150 rtc_update_alarm(&rtc_alarm);
151
Russell Kinga0164a52012-01-19 11:55:21 +0000152 spin_unlock(&sa1100_rtc_lock);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800153
154 return IRQ_HANDLED;
155}
156
Richard Purdiee842f1c2006-03-27 01:16:46 -0800157static int sa1100_rtc_open(struct device *dev)
158{
159 int ret;
Russell Kinga0164a52012-01-19 11:55:21 +0000160 struct platform_device *plat_dev = to_platform_device(dev);
161 struct rtc_device *rtc = platform_get_drvdata(plat_dev);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800162
Russell Kinga0164a52012-01-19 11:55:21 +0000163 ret = request_irq(IRQ_RTC1Hz, sa1100_rtc_interrupt, IRQF_DISABLED,
164 "rtc 1Hz", dev);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800165 if (ret) {
Russell Kinga0164a52012-01-19 11:55:21 +0000166 dev_err(dev, "IRQ %d already in use.\n", IRQ_RTC1Hz);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800167 goto fail_ui;
168 }
Russell Kinga0164a52012-01-19 11:55:21 +0000169 ret = request_irq(IRQ_RTCAlrm, sa1100_rtc_interrupt, IRQF_DISABLED,
170 "rtc Alrm", dev);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800171 if (ret) {
Russell Kinga0164a52012-01-19 11:55:21 +0000172 dev_err(dev, "IRQ %d already in use.\n", IRQ_RTCAlrm);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800173 goto fail_ai;
174 }
Russell Kinga0164a52012-01-19 11:55:21 +0000175 rtc->max_user_freq = RTC_FREQ;
176 rtc_irq_set_freq(rtc, NULL, RTC_FREQ);
Marcelo Roberto Jimenezd2ccb522010-12-16 21:31:32 +0100177
Richard Purdiee842f1c2006-03-27 01:16:46 -0800178 return 0;
179
Richard Purdiee842f1c2006-03-27 01:16:46 -0800180 fail_ai:
Russell Kinga0164a52012-01-19 11:55:21 +0000181 free_irq(IRQ_RTC1Hz, dev);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800182 fail_ui:
183 return ret;
184}
185
186static void sa1100_rtc_release(struct device *dev)
187{
Russell Kinga0164a52012-01-19 11:55:21 +0000188 spin_lock_irq(&sa1100_rtc_lock);
189 RTSR = 0;
190 spin_unlock_irq(&sa1100_rtc_lock);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800191
Russell Kinga0164a52012-01-19 11:55:21 +0000192 free_irq(IRQ_RTCAlrm, dev);
193 free_irq(IRQ_RTC1Hz, dev);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800194}
195
John Stultz16380c12011-02-02 17:02:41 -0800196static int sa1100_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
197{
Russell Kinga0164a52012-01-19 11:55:21 +0000198 spin_lock_irq(&sa1100_rtc_lock);
John Stultz16380c12011-02-02 17:02:41 -0800199 if (enabled)
Russell Kinga0164a52012-01-19 11:55:21 +0000200 RTSR |= RTSR_ALE;
John Stultz16380c12011-02-02 17:02:41 -0800201 else
Russell Kinga0164a52012-01-19 11:55:21 +0000202 RTSR &= ~RTSR_ALE;
203 spin_unlock_irq(&sa1100_rtc_lock);
John Stultz16380c12011-02-02 17:02:41 -0800204 return 0;
205}
206
Richard Purdiee842f1c2006-03-27 01:16:46 -0800207static int sa1100_rtc_read_time(struct device *dev, struct rtc_time *tm)
208{
Russell Kinga0164a52012-01-19 11:55:21 +0000209 rtc_time_to_tm(RCNR, tm);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800210 return 0;
211}
212
213static int sa1100_rtc_set_time(struct device *dev, struct rtc_time *tm)
214{
215 unsigned long time;
216 int ret;
217
218 ret = rtc_tm_to_time(tm, &time);
219 if (ret == 0)
Russell Kinga0164a52012-01-19 11:55:21 +0000220 RCNR = time;
Richard Purdiee842f1c2006-03-27 01:16:46 -0800221 return ret;
222}
223
224static int sa1100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
225{
Russell Kinga0164a52012-01-19 11:55:21 +0000226 u32 rtsr;
David Brownell32b49da2007-02-20 13:58:13 -0800227
Russell Kinga0164a52012-01-19 11:55:21 +0000228 memcpy(&alrm->time, &rtc_alarm, sizeof(struct rtc_time));
229 rtsr = RTSR;
David Brownell32b49da2007-02-20 13:58:13 -0800230 alrm->enabled = (rtsr & RTSR_ALE) ? 1 : 0;
231 alrm->pending = (rtsr & RTSR_AL) ? 1 : 0;
Richard Purdiee842f1c2006-03-27 01:16:46 -0800232 return 0;
233}
234
235static int sa1100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
236{
Russell Kinga0164a52012-01-19 11:55:21 +0000237 int ret;
Richard Purdiee842f1c2006-03-27 01:16:46 -0800238
Russell Kinga0164a52012-01-19 11:55:21 +0000239 spin_lock_irq(&sa1100_rtc_lock);
Russell King57270fc2012-01-19 11:50:40 +0000240 ret = rtc_update_alarm(&alrm->time);
241 if (ret == 0) {
242 if (alrm->enabled)
243 RTSR |= RTSR_ALE;
244 else
245 RTSR &= ~RTSR_ALE;
246 }
Russell Kinga0164a52012-01-19 11:55:21 +0000247 spin_unlock_irq(&sa1100_rtc_lock);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800248
Russell Kinga0164a52012-01-19 11:55:21 +0000249 return ret;
Richard Purdiee842f1c2006-03-27 01:16:46 -0800250}
251
252static int sa1100_rtc_proc(struct device *dev, struct seq_file *seq)
253{
Russell Kinga0164a52012-01-19 11:55:21 +0000254 seq_printf(seq, "trim/divider\t\t: 0x%08x\n", (u32) RTTR);
255 seq_printf(seq, "RTSR\t\t\t: 0x%08x\n", (u32)RTSR);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800256
257 return 0;
258}
259
David Brownellff8371a2006-09-30 23:28:17 -0700260static const struct rtc_class_ops sa1100_rtc_ops = {
Richard Purdiee842f1c2006-03-27 01:16:46 -0800261 .open = sa1100_rtc_open,
Richard Purdiee842f1c2006-03-27 01:16:46 -0800262 .release = sa1100_rtc_release,
Richard Purdiee842f1c2006-03-27 01:16:46 -0800263 .read_time = sa1100_rtc_read_time,
264 .set_time = sa1100_rtc_set_time,
265 .read_alarm = sa1100_rtc_read_alarm,
266 .set_alarm = sa1100_rtc_set_alarm,
267 .proc = sa1100_rtc_proc,
John Stultz16380c12011-02-02 17:02:41 -0800268 .alarm_irq_enable = sa1100_rtc_alarm_irq_enable,
Richard Purdiee842f1c2006-03-27 01:16:46 -0800269};
270
271static int sa1100_rtc_probe(struct platform_device *pdev)
272{
Russell Kinga0164a52012-01-19 11:55:21 +0000273 struct rtc_device *rtc;
Richard Purdiee842f1c2006-03-27 01:16:46 -0800274
275 /*
276 * According to the manual we should be able to let RTTR be zero
277 * and then a default diviser for a 32.768KHz clock is used.
278 * Apparently this doesn't work, at least for my SA1110 rev 5.
279 * If the clock divider is uninitialized then reset it to the
280 * default value to get the 1Hz clock.
281 */
Russell Kinga0164a52012-01-19 11:55:21 +0000282 if (RTTR == 0) {
283 RTTR = RTC_DEF_DIVIDER + (RTC_DEF_TRIM << 16);
284 dev_warn(&pdev->dev, "warning: "
285 "initializing default clock divider/trim value\n");
Richard Purdiee842f1c2006-03-27 01:16:46 -0800286 /* The current RTC value probably doesn't make sense either */
Russell Kinga0164a52012-01-19 11:55:21 +0000287 RCNR = 0;
Richard Purdiee842f1c2006-03-27 01:16:46 -0800288 }
289
Uli Luckase5a2c9c2008-06-18 09:54:03 +0100290 device_init_wakeup(&pdev->dev, 1);
291
Russell Kinga0164a52012-01-19 11:55:21 +0000292 rtc = rtc_device_register(pdev->name, &pdev->dev, &sa1100_rtc_ops,
293 THIS_MODULE);
294
295 if (IS_ERR(rtc))
296 return PTR_ERR(rtc);
297
298 platform_set_drvdata(pdev, rtc);
299
Marcelo Roberto Jimenez7decaa52010-10-18 22:35:54 +0100300 /* Fix for a nasty initialization problem the in SA11xx RTSR register.
301 * See also the comments in sa1100_rtc_interrupt().
302 *
303 * Sometimes bit 1 of the RTSR (RTSR_HZ) will wake up 1, which means an
304 * interrupt pending, even though interrupts were never enabled.
305 * In this case, this bit it must be reset before enabling
306 * interruptions to avoid a nonexistent interrupt to occur.
307 *
308 * In principle, the same problem would apply to bit 0, although it has
309 * never been observed to happen.
310 *
311 * This issue is addressed both here and in sa1100_rtc_interrupt().
312 * If the issue is not addressed here, in the times when the processor
313 * wakes up with the bit set there will be one spurious interrupt.
314 *
315 * The issue is also dealt with in sa1100_rtc_interrupt() to be on the
316 * safe side, once the condition that lead to this strange
317 * initialization is unknown and could in principle happen during
318 * normal processing.
319 *
320 * Notice that clearing bit 1 and 0 is accomplished by writting ONES to
321 * the corresponding bits in RTSR. */
Russell Kinga0164a52012-01-19 11:55:21 +0000322 RTSR = RTSR_AL | RTSR_HZ;
Marcelo Roberto Jimenez7decaa52010-10-18 22:35:54 +0100323
Richard Purdiee842f1c2006-03-27 01:16:46 -0800324 return 0;
325}
326
327static int sa1100_rtc_remove(struct platform_device *pdev)
328{
Russell Kinga0164a52012-01-19 11:55:21 +0000329 struct rtc_device *rtc = platform_get_drvdata(pdev);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800330
Russell Kinga0164a52012-01-19 11:55:21 +0000331 if (rtc)
332 rtc_device_unregister(rtc);
333
Richard Purdiee842f1c2006-03-27 01:16:46 -0800334 return 0;
335}
336
Russell King6bc54e62007-11-12 22:49:58 +0000337#ifdef CONFIG_PM
Haojian Zhuang5d027cd2009-07-21 14:31:09 +0800338static int sa1100_rtc_suspend(struct device *dev)
Russell King6bc54e62007-11-12 22:49:58 +0000339{
Haojian Zhuang5d027cd2009-07-21 14:31:09 +0800340 if (device_may_wakeup(dev))
Russell Kinga0164a52012-01-19 11:55:21 +0000341 enable_irq_wake(IRQ_RTCAlrm);
Russell King6bc54e62007-11-12 22:49:58 +0000342 return 0;
343}
344
Haojian Zhuang5d027cd2009-07-21 14:31:09 +0800345static int sa1100_rtc_resume(struct device *dev)
Russell King6bc54e62007-11-12 22:49:58 +0000346{
Haojian Zhuang5d027cd2009-07-21 14:31:09 +0800347 if (device_may_wakeup(dev))
Russell Kinga0164a52012-01-19 11:55:21 +0000348 disable_irq_wake(IRQ_RTCAlrm);
Russell King6bc54e62007-11-12 22:49:58 +0000349 return 0;
350}
Haojian Zhuang5d027cd2009-07-21 14:31:09 +0800351
Alexey Dobriyan47145212009-12-14 18:00:08 -0800352static const struct dev_pm_ops sa1100_rtc_pm_ops = {
Haojian Zhuang5d027cd2009-07-21 14:31:09 +0800353 .suspend = sa1100_rtc_suspend,
354 .resume = sa1100_rtc_resume,
355};
Russell King6bc54e62007-11-12 22:49:58 +0000356#endif
357
Richard Purdiee842f1c2006-03-27 01:16:46 -0800358static struct platform_driver sa1100_rtc_driver = {
359 .probe = sa1100_rtc_probe,
360 .remove = sa1100_rtc_remove,
Richard Purdiee842f1c2006-03-27 01:16:46 -0800361 .driver = {
Haojian Zhuang5d027cd2009-07-21 14:31:09 +0800362 .name = "sa1100-rtc",
363#ifdef CONFIG_PM
364 .pm = &sa1100_rtc_pm_ops,
365#endif
Richard Purdiee842f1c2006-03-27 01:16:46 -0800366 },
367};
368
Axel Lin0c4eae62012-01-10 15:10:48 -0800369module_platform_driver(sa1100_rtc_driver);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800370
371MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
372MODULE_DESCRIPTION("SA11x0/PXA2xx Realtime Clock Driver (RTC)");
373MODULE_LICENSE("GPL");
Kay Sieversad28a072008-04-10 21:29:25 -0700374MODULE_ALIAS("platform:sa1100-rtc");