2 * Real Time Clock interface for StrongARM SA1x00 and XScale PXA2xx
4 * Copyright (c) 2000 Nils Faerber
6 * Based on rtc.c by Paul Gortmaker
8 * Original Driver by Nils Faerber <nils@kernelconcepts.de>
11 * CIH <cih@coventive.com>
12 * Nicolas Pitre <nico@cam.org>
13 * Andrew Christian <andrew.christian@hp.com>
15 * Converted to the RTC subsystem and Driver Model
16 * by Richard Purdie <rpurdie@rpsys.net>
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.
24 #include <linux/platform_device.h>
25 #include <linux/module.h>
26 #include <linux/rtc.h>
27 #include <linux/init.h>
29 #include <linux/interrupt.h>
30 #include <linux/string.h>
32 #include <linux/bitops.h>
34 #include <mach/hardware.h>
37 #ifdef CONFIG_ARCH_PXA
38 #include <mach/pxa-regs.h>
41 #define RTC_DEF_DIVIDER 32768 - 1
42 #define RTC_DEF_TRIM 0
44 static unsigned long rtc_freq
= 1024;
45 static unsigned long timer_freq
;
46 static struct rtc_time rtc_alarm
;
47 static DEFINE_SPINLOCK(sa1100_rtc_lock
);
49 static inline int rtc_periodic_alarm(struct rtc_time
*tm
)
51 return (tm
->tm_year
== -1) ||
52 ((unsigned)tm
->tm_mon
>= 12) ||
53 ((unsigned)(tm
->tm_mday
- 1) >= 31) ||
54 ((unsigned)tm
->tm_hour
> 23) ||
55 ((unsigned)tm
->tm_min
> 59) ||
56 ((unsigned)tm
->tm_sec
> 59);
60 * Calculate the next alarm time given the requested alarm time mask
61 * and the current time.
63 static void rtc_next_alarm_time(struct rtc_time
*next
, struct rtc_time
*now
, struct rtc_time
*alrm
)
65 unsigned long next_time
;
66 unsigned long now_time
;
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
;
75 rtc_tm_to_time(now
, &now_time
);
76 rtc_tm_to_time(next
, &next_time
);
78 if (next_time
< now_time
) {
80 next_time
+= 60 * 60 * 24;
81 rtc_time_to_tm(next_time
, next
);
85 static int rtc_update_alarm(struct rtc_time
*alrm
)
87 struct rtc_time alarm_tm
, now_tm
;
88 unsigned long now
, time
;
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
);
99 RTSR
= RTSR
& (RTSR_HZE
|RTSR_ALE
|RTSR_AL
);
101 } while (now
!= RCNR
);
106 static irqreturn_t
sa1100_rtc_interrupt(int irq
, void *dev_id
)
108 struct platform_device
*pdev
= to_platform_device(dev_id
);
109 struct rtc_device
*rtc
= platform_get_drvdata(pdev
);
111 unsigned long events
= 0;
113 spin_lock(&sa1100_rtc_lock
);
116 /* clear interrupt sources */
118 RTSR
= (RTSR_AL
| RTSR_HZ
) & (rtsr
>> 2);
120 /* clear alarm interrupt if it has occurred */
123 RTSR
= rtsr
& (RTSR_ALE
| RTSR_HZE
);
125 /* update irq data & counter */
127 events
|= RTC_AF
| RTC_IRQF
;
129 events
|= RTC_UF
| RTC_IRQF
;
131 rtc_update_irq(rtc
, 1, events
);
133 if (rtsr
& RTSR_AL
&& rtc_periodic_alarm(&rtc_alarm
))
134 rtc_update_alarm(&rtc_alarm
);
136 spin_unlock(&sa1100_rtc_lock
);
141 static int rtc_timer1_count
;
143 static irqreturn_t
timer1_interrupt(int irq
, void *dev_id
)
145 struct platform_device
*pdev
= to_platform_device(dev_id
);
146 struct rtc_device
*rtc
= platform_get_drvdata(pdev
);
149 * If we match for the first time, rtc_timer1_count will be 1.
150 * Otherwise, we wrapped around (very unlikely but
151 * still possible) so compute the amount of missed periods.
152 * The match reg is updated only when the data is actually retrieved
153 * to avoid unnecessary interrupts.
155 OSSR
= OSSR_M1
; /* clear match on timer1 */
157 rtc_update_irq(rtc
, rtc_timer1_count
, RTC_PF
| RTC_IRQF
);
159 if (rtc_timer1_count
== 1)
160 rtc_timer1_count
= (rtc_freq
* ((1 << 30) / (timer_freq
>> 2)));
165 static int sa1100_rtc_read_callback(struct device
*dev
, int data
)
168 /* interpolate missed periods and set match for the next */
169 unsigned long period
= timer_freq
/ rtc_freq
;
170 unsigned long oscr
= OSCR
;
171 unsigned long osmr1
= OSMR1
;
172 unsigned long missed
= (oscr
- osmr1
)/period
;
174 OSSR
= OSSR_M1
; /* clear match on timer 1 */
175 OSMR1
= osmr1
+ (missed
+ 1)*period
;
176 /* Ensure we didn't miss another match in the mean time.
177 * Here we compare (match - OSCR) 8 instead of 0 --
178 * see comment in pxa_timer_interrupt() for explanation.
180 while( (signed long)((osmr1
= OSMR1
) - OSCR
) <= 8 ) {
182 OSSR
= OSSR_M1
; /* clear match on timer 1 */
183 OSMR1
= osmr1
+ period
;
189 static int sa1100_rtc_open(struct device
*dev
)
193 ret
= request_irq(IRQ_RTC1Hz
, sa1100_rtc_interrupt
, IRQF_DISABLED
,
196 dev_err(dev
, "IRQ %d already in use.\n", IRQ_RTC1Hz
);
199 ret
= request_irq(IRQ_RTCAlrm
, sa1100_rtc_interrupt
, IRQF_DISABLED
,
202 dev_err(dev
, "IRQ %d already in use.\n", IRQ_RTCAlrm
);
205 ret
= request_irq(IRQ_OST1
, timer1_interrupt
, IRQF_DISABLED
,
208 dev_err(dev
, "IRQ %d already in use.\n", IRQ_OST1
);
214 free_irq(IRQ_RTCAlrm
, dev
);
216 free_irq(IRQ_RTC1Hz
, dev
);
221 static void sa1100_rtc_release(struct device
*dev
)
223 spin_lock_irq(&sa1100_rtc_lock
);
227 spin_unlock_irq(&sa1100_rtc_lock
);
229 free_irq(IRQ_OST1
, dev
);
230 free_irq(IRQ_RTCAlrm
, dev
);
231 free_irq(IRQ_RTC1Hz
, dev
);
235 static int sa1100_rtc_ioctl(struct device
*dev
, unsigned int cmd
,
240 spin_lock_irq(&sa1100_rtc_lock
);
242 spin_unlock_irq(&sa1100_rtc_lock
);
245 spin_lock_irq(&sa1100_rtc_lock
);
247 spin_unlock_irq(&sa1100_rtc_lock
);
250 spin_lock_irq(&sa1100_rtc_lock
);
252 spin_unlock_irq(&sa1100_rtc_lock
);
255 spin_lock_irq(&sa1100_rtc_lock
);
257 spin_unlock_irq(&sa1100_rtc_lock
);
260 spin_lock_irq(&sa1100_rtc_lock
);
262 spin_unlock_irq(&sa1100_rtc_lock
);
265 spin_lock_irq(&sa1100_rtc_lock
);
266 OSMR1
= timer_freq
/ rtc_freq
+ OSCR
;
268 rtc_timer1_count
= 1;
269 spin_unlock_irq(&sa1100_rtc_lock
);
272 return put_user(rtc_freq
, (unsigned long *)arg
);
274 if (arg
< 1 || arg
> timer_freq
)
282 static int sa1100_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
284 rtc_time_to_tm(RCNR
, tm
);
288 static int sa1100_rtc_set_time(struct device
*dev
, struct rtc_time
*tm
)
293 ret
= rtc_tm_to_time(tm
, &time
);
299 static int sa1100_rtc_read_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
303 memcpy(&alrm
->time
, &rtc_alarm
, sizeof(struct rtc_time
));
305 alrm
->enabled
= (rtsr
& RTSR_ALE
) ? 1 : 0;
306 alrm
->pending
= (rtsr
& RTSR_AL
) ? 1 : 0;
310 static int sa1100_rtc_set_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
314 spin_lock_irq(&sa1100_rtc_lock
);
315 ret
= rtc_update_alarm(&alrm
->time
);
322 spin_unlock_irq(&sa1100_rtc_lock
);
327 static int sa1100_rtc_proc(struct device
*dev
, struct seq_file
*seq
)
329 seq_printf(seq
, "trim/divider\t: 0x%08x\n", (u32
) RTTR
);
330 seq_printf(seq
, "update_IRQ\t: %s\n",
331 (RTSR
& RTSR_HZE
) ? "yes" : "no");
332 seq_printf(seq
, "periodic_IRQ\t: %s\n",
333 (OIER
& OIER_E1
) ? "yes" : "no");
334 seq_printf(seq
, "periodic_freq\t: %ld\n", rtc_freq
);
339 static const struct rtc_class_ops sa1100_rtc_ops
= {
340 .open
= sa1100_rtc_open
,
341 .read_callback
= sa1100_rtc_read_callback
,
342 .release
= sa1100_rtc_release
,
343 .ioctl
= sa1100_rtc_ioctl
,
344 .read_time
= sa1100_rtc_read_time
,
345 .set_time
= sa1100_rtc_set_time
,
346 .read_alarm
= sa1100_rtc_read_alarm
,
347 .set_alarm
= sa1100_rtc_set_alarm
,
348 .proc
= sa1100_rtc_proc
,
351 static int sa1100_rtc_probe(struct platform_device
*pdev
)
353 struct rtc_device
*rtc
;
355 timer_freq
= get_clock_tick_rate();
358 * According to the manual we should be able to let RTTR be zero
359 * and then a default diviser for a 32.768KHz clock is used.
360 * Apparently this doesn't work, at least for my SA1110 rev 5.
361 * If the clock divider is uninitialized then reset it to the
362 * default value to get the 1Hz clock.
365 RTTR
= RTC_DEF_DIVIDER
+ (RTC_DEF_TRIM
<< 16);
366 dev_warn(&pdev
->dev
, "warning: initializing default clock divider/trim value\n");
367 /* The current RTC value probably doesn't make sense either */
371 device_init_wakeup(&pdev
->dev
, 1);
373 rtc
= rtc_device_register(pdev
->name
, &pdev
->dev
, &sa1100_rtc_ops
,
379 platform_set_drvdata(pdev
, rtc
);
384 static int sa1100_rtc_remove(struct platform_device
*pdev
)
386 struct rtc_device
*rtc
= platform_get_drvdata(pdev
);
389 rtc_device_unregister(rtc
);
395 static int sa1100_rtc_suspend(struct platform_device
*pdev
, pm_message_t state
)
397 if (device_may_wakeup(&pdev
->dev
))
398 enable_irq_wake(IRQ_RTCAlrm
);
402 static int sa1100_rtc_resume(struct platform_device
*pdev
)
404 if (device_may_wakeup(&pdev
->dev
))
405 disable_irq_wake(IRQ_RTCAlrm
);
409 #define sa1100_rtc_suspend NULL
410 #define sa1100_rtc_resume NULL
413 static struct platform_driver sa1100_rtc_driver
= {
414 .probe
= sa1100_rtc_probe
,
415 .remove
= sa1100_rtc_remove
,
416 .suspend
= sa1100_rtc_suspend
,
417 .resume
= sa1100_rtc_resume
,
419 .name
= "sa1100-rtc",
423 static int __init
sa1100_rtc_init(void)
425 return platform_driver_register(&sa1100_rtc_driver
);
428 static void __exit
sa1100_rtc_exit(void)
430 platform_driver_unregister(&sa1100_rtc_driver
);
433 module_init(sa1100_rtc_init
);
434 module_exit(sa1100_rtc_exit
);
436 MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
437 MODULE_DESCRIPTION("SA11x0/PXA2xx Realtime Clock Driver (RTC)");
438 MODULE_LICENSE("GPL");
439 MODULE_ALIAS("platform:sa1100-rtc");