rtc: sa1100: remove periodic code
[linux-2.6-block.git] / drivers / rtc / rtc-sa1100.c
CommitLineData
e842f1c8
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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>
2f82af08 12 * Nicolas Pitre <nico@fluxnic.net>
e842f1c8
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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>
a0164a57 30#include <linux/string.h>
e842f1c8 31#include <linux/pm.h>
a0164a57 32#include <linux/bitops.h>
e842f1c8 33
a09e64fb 34#include <mach/hardware.h>
e842f1c8 35#include <asm/irq.h>
e842f1c8 36
a0164a57
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37#ifdef CONFIG_ARCH_PXA
38#include <mach/regs-rtc.h>
39#endif
40
a404ad1f 41#define RTC_DEF_DIVIDER (32768 - 1)
e842f1c8 42#define RTC_DEF_TRIM 0
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43
44static const unsigned long RTC_FREQ = 1024;
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45static DEFINE_SPINLOCK(sa1100_rtc_lock);
46
797276ec
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47/*
48 * Calculate the next alarm time given the requested alarm time mask
49 * and the current time.
50 */
a404ad1f
MRJ
51static void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now,
52 struct rtc_time *alrm)
797276ec
RK
53{
54 unsigned long next_time;
55 unsigned long now_time;
56
57 next->tm_year = now->tm_year;
58 next->tm_mon = now->tm_mon;
59 next->tm_mday = now->tm_mday;
60 next->tm_hour = alrm->tm_hour;
61 next->tm_min = alrm->tm_min;
62 next->tm_sec = alrm->tm_sec;
63
64 rtc_tm_to_time(now, &now_time);
65 rtc_tm_to_time(next, &next_time);
66
67 if (next_time < now_time) {
68 /* Advance one day */
69 next_time += 60 * 60 * 24;
70 rtc_time_to_tm(next_time, next);
71 }
72}
73
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RK
74static int rtc_update_alarm(struct rtc_time *alrm)
75{
76 struct rtc_time alarm_tm, now_tm;
77 unsigned long now, time;
78 int ret;
79
80 do {
81 now = RCNR;
82 rtc_time_to_tm(now, &now_tm);
83 rtc_next_alarm_time(&alarm_tm, &now_tm, alrm);
84 ret = rtc_tm_to_time(&alarm_tm, &time);
85 if (ret != 0)
86 break;
87
88 RTSR = RTSR & (RTSR_HZE|RTSR_ALE|RTSR_AL);
89 RTAR = time;
90 } while (now != RCNR);
91
92 return ret;
93}
94
7d12e780 95static irqreturn_t sa1100_rtc_interrupt(int irq, void *dev_id)
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96{
97 struct platform_device *pdev = to_platform_device(dev_id);
a0164a57 98 struct rtc_device *rtc = platform_get_drvdata(pdev);
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99 unsigned int rtsr;
100 unsigned long events = 0;
101
a0164a57 102 spin_lock(&sa1100_rtc_lock);
e842f1c8 103
a0164a57 104 rtsr = RTSR;
e842f1c8 105 /* clear interrupt sources */
a0164a57 106 RTSR = 0;
7decaa55
MRJ
107 /* Fix for a nasty initialization problem the in SA11xx RTSR register.
108 * See also the comments in sa1100_rtc_probe(). */
109 if (rtsr & (RTSR_ALE | RTSR_HZE)) {
110 /* This is the original code, before there was the if test
111 * above. This code does not clear interrupts that were not
112 * enabled. */
a0164a57 113 RTSR = (RTSR_AL | RTSR_HZ) & (rtsr >> 2);
7decaa55
MRJ
114 } else {
115 /* For some reason, it is possible to enter this routine
116 * without interruptions enabled, it has been tested with
117 * several units (Bug in SA11xx chip?).
118 *
119 * This situation leads to an infinite "loop" of interrupt
120 * routine calling and as a result the processor seems to
121 * lock on its first call to open(). */
a0164a57 122 RTSR = RTSR_AL | RTSR_HZ;
7decaa55 123 }
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124
125 /* clear alarm interrupt if it has occurred */
126 if (rtsr & RTSR_AL)
127 rtsr &= ~RTSR_ALE;
a0164a57 128 RTSR = rtsr & (RTSR_ALE | RTSR_HZE);
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129
130 /* update irq data & counter */
131 if (rtsr & RTSR_AL)
132 events |= RTC_AF | RTC_IRQF;
133 if (rtsr & RTSR_HZ)
134 events |= RTC_UF | RTC_IRQF;
135
a0164a57 136 rtc_update_irq(rtc, 1, events);
e842f1c8 137
a0164a57 138 spin_unlock(&sa1100_rtc_lock);
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139
140 return IRQ_HANDLED;
141}
142
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143static int sa1100_rtc_open(struct device *dev)
144{
145 int ret;
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146 struct platform_device *plat_dev = to_platform_device(dev);
147 struct rtc_device *rtc = platform_get_drvdata(plat_dev);
e842f1c8 148
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149 ret = request_irq(IRQ_RTC1Hz, sa1100_rtc_interrupt, IRQF_DISABLED,
150 "rtc 1Hz", dev);
e842f1c8 151 if (ret) {
a0164a57 152 dev_err(dev, "IRQ %d already in use.\n", IRQ_RTC1Hz);
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153 goto fail_ui;
154 }
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155 ret = request_irq(IRQ_RTCAlrm, sa1100_rtc_interrupt, IRQF_DISABLED,
156 "rtc Alrm", dev);
e842f1c8 157 if (ret) {
a0164a57 158 dev_err(dev, "IRQ %d already in use.\n", IRQ_RTCAlrm);
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159 goto fail_ai;
160 }
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161 rtc->max_user_freq = RTC_FREQ;
162 rtc_irq_set_freq(rtc, NULL, RTC_FREQ);
d2ccb52d 163
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164 return 0;
165
e842f1c8 166 fail_ai:
a0164a57 167 free_irq(IRQ_RTC1Hz, dev);
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168 fail_ui:
169 return ret;
170}
171
172static void sa1100_rtc_release(struct device *dev)
173{
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174 spin_lock_irq(&sa1100_rtc_lock);
175 RTSR = 0;
176 spin_unlock_irq(&sa1100_rtc_lock);
e842f1c8 177
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178 free_irq(IRQ_RTCAlrm, dev);
179 free_irq(IRQ_RTC1Hz, dev);
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180}
181
16380c15
JS
182static int sa1100_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
183{
a0164a57 184 spin_lock_irq(&sa1100_rtc_lock);
16380c15 185 if (enabled)
a0164a57 186 RTSR |= RTSR_ALE;
16380c15 187 else
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188 RTSR &= ~RTSR_ALE;
189 spin_unlock_irq(&sa1100_rtc_lock);
16380c15
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190 return 0;
191}
192
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193static int sa1100_rtc_read_time(struct device *dev, struct rtc_time *tm)
194{
a0164a57 195 rtc_time_to_tm(RCNR, tm);
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196 return 0;
197}
198
199static int sa1100_rtc_set_time(struct device *dev, struct rtc_time *tm)
200{
201 unsigned long time;
202 int ret;
203
204 ret = rtc_tm_to_time(tm, &time);
205 if (ret == 0)
a0164a57 206 RCNR = time;
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207 return ret;
208}
209
210static int sa1100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
211{
a0164a57 212 u32 rtsr;
32b49da4 213
a0164a57 214 rtsr = RTSR;
32b49da4
DB
215 alrm->enabled = (rtsr & RTSR_ALE) ? 1 : 0;
216 alrm->pending = (rtsr & RTSR_AL) ? 1 : 0;
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217 return 0;
218}
219
220static int sa1100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
221{
a0164a57 222 int ret;
e842f1c8 223
a0164a57 224 spin_lock_irq(&sa1100_rtc_lock);
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225 ret = rtc_update_alarm(&alrm->time);
226 if (ret == 0) {
227 if (alrm->enabled)
228 RTSR |= RTSR_ALE;
229 else
230 RTSR &= ~RTSR_ALE;
231 }
a0164a57 232 spin_unlock_irq(&sa1100_rtc_lock);
e842f1c8 233
a0164a57 234 return ret;
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235}
236
237static int sa1100_rtc_proc(struct device *dev, struct seq_file *seq)
238{
a0164a57
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239 seq_printf(seq, "trim/divider\t\t: 0x%08x\n", (u32) RTTR);
240 seq_printf(seq, "RTSR\t\t\t: 0x%08x\n", (u32)RTSR);
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241
242 return 0;
243}
244
ff8371ac 245static const struct rtc_class_ops sa1100_rtc_ops = {
e842f1c8 246 .open = sa1100_rtc_open,
e842f1c8 247 .release = sa1100_rtc_release,
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248 .read_time = sa1100_rtc_read_time,
249 .set_time = sa1100_rtc_set_time,
250 .read_alarm = sa1100_rtc_read_alarm,
251 .set_alarm = sa1100_rtc_set_alarm,
252 .proc = sa1100_rtc_proc,
16380c15 253 .alarm_irq_enable = sa1100_rtc_alarm_irq_enable,
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254};
255
256static int sa1100_rtc_probe(struct platform_device *pdev)
257{
a0164a57 258 struct rtc_device *rtc;
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259
260 /*
261 * According to the manual we should be able to let RTTR be zero
262 * and then a default diviser for a 32.768KHz clock is used.
263 * Apparently this doesn't work, at least for my SA1110 rev 5.
264 * If the clock divider is uninitialized then reset it to the
265 * default value to get the 1Hz clock.
266 */
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267 if (RTTR == 0) {
268 RTTR = RTC_DEF_DIVIDER + (RTC_DEF_TRIM << 16);
269 dev_warn(&pdev->dev, "warning: "
270 "initializing default clock divider/trim value\n");
e842f1c8 271 /* The current RTC value probably doesn't make sense either */
a0164a57 272 RCNR = 0;
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273 }
274
e5a2c9cc
UL
275 device_init_wakeup(&pdev->dev, 1);
276
a0164a57
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277 rtc = rtc_device_register(pdev->name, &pdev->dev, &sa1100_rtc_ops,
278 THIS_MODULE);
279
280 if (IS_ERR(rtc))
281 return PTR_ERR(rtc);
282
283 platform_set_drvdata(pdev, rtc);
284
7decaa55
MRJ
285 /* Fix for a nasty initialization problem the in SA11xx RTSR register.
286 * See also the comments in sa1100_rtc_interrupt().
287 *
288 * Sometimes bit 1 of the RTSR (RTSR_HZ) will wake up 1, which means an
289 * interrupt pending, even though interrupts were never enabled.
290 * In this case, this bit it must be reset before enabling
291 * interruptions to avoid a nonexistent interrupt to occur.
292 *
293 * In principle, the same problem would apply to bit 0, although it has
294 * never been observed to happen.
295 *
296 * This issue is addressed both here and in sa1100_rtc_interrupt().
297 * If the issue is not addressed here, in the times when the processor
298 * wakes up with the bit set there will be one spurious interrupt.
299 *
300 * The issue is also dealt with in sa1100_rtc_interrupt() to be on the
301 * safe side, once the condition that lead to this strange
302 * initialization is unknown and could in principle happen during
303 * normal processing.
304 *
305 * Notice that clearing bit 1 and 0 is accomplished by writting ONES to
306 * the corresponding bits in RTSR. */
a0164a57 307 RTSR = RTSR_AL | RTSR_HZ;
7decaa55 308
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309 return 0;
310}
311
312static int sa1100_rtc_remove(struct platform_device *pdev)
313{
a0164a57
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314 struct rtc_device *rtc = platform_get_drvdata(pdev);
315
316 if (rtc)
317 rtc_device_unregister(rtc);
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318
319 return 0;
320}
321
6bc54e69 322#ifdef CONFIG_PM
5d027cd2 323static int sa1100_rtc_suspend(struct device *dev)
6bc54e69 324{
5d027cd2 325 if (device_may_wakeup(dev))
a0164a57 326 enable_irq_wake(IRQ_RTCAlrm);
6bc54e69
RK
327 return 0;
328}
329
5d027cd2 330static int sa1100_rtc_resume(struct device *dev)
6bc54e69 331{
5d027cd2 332 if (device_may_wakeup(dev))
a0164a57 333 disable_irq_wake(IRQ_RTCAlrm);
6bc54e69
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334 return 0;
335}
5d027cd2 336
47145210 337static const struct dev_pm_ops sa1100_rtc_pm_ops = {
5d027cd2
HZ
338 .suspend = sa1100_rtc_suspend,
339 .resume = sa1100_rtc_resume,
340};
6bc54e69
RK
341#endif
342
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343static struct platform_driver sa1100_rtc_driver = {
344 .probe = sa1100_rtc_probe,
345 .remove = sa1100_rtc_remove,
346 .driver = {
5d027cd2
HZ
347 .name = "sa1100-rtc",
348#ifdef CONFIG_PM
349 .pm = &sa1100_rtc_pm_ops,
350#endif
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351 },
352};
353
0c4eae66 354module_platform_driver(sa1100_rtc_driver);
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355
356MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
357MODULE_DESCRIPTION("SA11x0/PXA2xx Realtime Clock Driver (RTC)");
358MODULE_LICENSE("GPL");
ad28a07b 359MODULE_ALIAS("platform:sa1100-rtc");