1 /* drivers/char/s3c2410_rtc.c
3 * Copyright (c) 2004 Simtec Electronics <linux@simtec.co.uk>
4 * http://www.simtec.co.uk/products/SWLINUX/
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 * S3C2410 Internal RTC Driver
13 * 08-Nov-2004 BJD Initial creation
14 * 12-Nov-2004 BJD Added periodic IRQ and PM code
15 * 22-Nov-2004 BJD Sign-test on alarm code to check for <0
16 * 10-Mar-2005 LCVR Changed S3C2410_VA_RTC to S3C24XX_VA_RTC
19 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/init.h>
23 #include <linux/device.h>
24 #include <linux/interrupt.h>
25 #include <linux/rtc.h>
26 #include <linux/bcd.h>
28 #include <asm/hardware.h>
29 #include <asm/uaccess.h>
34 #include <asm/mach/time.h>
36 #include <asm/hardware/clock.h>
37 #include <asm/arch/regs-rtc.h>
39 /* need this for the RTC_AF definitions */
40 #include <linux/mc146818rtc.h>
43 #define S3C24XX_VA_RTC s3c2410_rtc_base
45 static struct resource
*s3c2410_rtc_mem
;
47 static void __iomem
*s3c2410_rtc_base
;
48 static int s3c2410_rtc_alarmno
= NO_IRQ
;
49 static int s3c2410_rtc_tickno
= NO_IRQ
;
50 static int s3c2410_rtc_freq
= 1;
52 static DEFINE_SPINLOCK(s3c2410_rtc_pie_lock
);
56 static irqreturn_t
s3c2410_rtc_alarmirq(int irq
, void *id
, struct pt_regs
*r
)
58 rtc_update(1, RTC_AF
| RTC_IRQF
);
62 static irqreturn_t
s3c2410_rtc_tickirq(int irq
, void *id
, struct pt_regs
*r
)
64 rtc_update(1, RTC_PF
| RTC_IRQF
);
68 /* Update control registers */
69 static void s3c2410_rtc_setaie(int to
)
73 pr_debug("%s: aie=%d\n", __FUNCTION__
, to
);
75 tmp
= readb(S3C2410_RTCALM
);
78 tmp
|= S3C2410_RTCALM_ALMEN
;
80 tmp
&= ~S3C2410_RTCALM_ALMEN
;
83 writeb(tmp
, S3C2410_RTCALM
);
86 static void s3c2410_rtc_setpie(int to
)
90 pr_debug("%s: pie=%d\n", __FUNCTION__
, to
);
92 spin_lock_irq(&s3c2410_rtc_pie_lock
);
93 tmp
= readb(S3C2410_TICNT
) & ~S3C2410_TICNT_ENABLE
;
96 tmp
|= S3C2410_TICNT_ENABLE
;
98 writeb(tmp
, S3C2410_TICNT
);
99 spin_unlock_irq(&s3c2410_rtc_pie_lock
);
102 static void s3c2410_rtc_setfreq(int freq
)
106 spin_lock_irq(&s3c2410_rtc_pie_lock
);
107 tmp
= readb(S3C2410_TICNT
) & S3C2410_TICNT_ENABLE
;
109 s3c2410_rtc_freq
= freq
;
111 tmp
|= (128 / freq
)-1;
113 writeb(tmp
, S3C2410_TICNT
);
114 spin_unlock_irq(&s3c2410_rtc_pie_lock
);
117 /* Time read/write */
119 static void s3c2410_rtc_gettime(struct rtc_time
*rtc_tm
)
121 unsigned int have_retried
= 0;
124 rtc_tm
->tm_min
= readb(S3C2410_RTCMIN
);
125 rtc_tm
->tm_hour
= readb(S3C2410_RTCHOUR
);
126 rtc_tm
->tm_mday
= readb(S3C2410_RTCDATE
);
127 rtc_tm
->tm_mon
= readb(S3C2410_RTCMON
);
128 rtc_tm
->tm_year
= readb(S3C2410_RTCYEAR
);
129 rtc_tm
->tm_sec
= readb(S3C2410_RTCSEC
);
131 /* the only way to work out wether the system was mid-update
132 * when we read it is to check the second counter, and if it
133 * is zero, then we re-try the entire read
136 if (rtc_tm
->tm_sec
== 0 && !have_retried
) {
141 pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
142 rtc_tm
->tm_year
, rtc_tm
->tm_mon
, rtc_tm
->tm_mday
,
143 rtc_tm
->tm_hour
, rtc_tm
->tm_min
, rtc_tm
->tm_sec
);
145 BCD_TO_BIN(rtc_tm
->tm_sec
);
146 BCD_TO_BIN(rtc_tm
->tm_min
);
147 BCD_TO_BIN(rtc_tm
->tm_hour
);
148 BCD_TO_BIN(rtc_tm
->tm_mday
);
149 BCD_TO_BIN(rtc_tm
->tm_mon
);
150 BCD_TO_BIN(rtc_tm
->tm_year
);
152 rtc_tm
->tm_year
+= 100;
157 static int s3c2410_rtc_settime(struct rtc_time
*tm
)
159 /* the rtc gets round the y2k problem by just not supporting it */
161 if (tm
->tm_year
< 100)
164 writeb(BIN2BCD(tm
->tm_sec
), S3C2410_RTCSEC
);
165 writeb(BIN2BCD(tm
->tm_min
), S3C2410_RTCMIN
);
166 writeb(BIN2BCD(tm
->tm_hour
), S3C2410_RTCHOUR
);
167 writeb(BIN2BCD(tm
->tm_mday
), S3C2410_RTCDATE
);
168 writeb(BIN2BCD(tm
->tm_mon
+ 1), S3C2410_RTCMON
);
169 writeb(BIN2BCD(tm
->tm_year
- 100), S3C2410_RTCYEAR
);
174 static void s3c2410_rtc_getalarm(struct rtc_wkalrm
*alrm
)
176 struct rtc_time
*alm_tm
= &alrm
->time
;
179 alm_tm
->tm_sec
= readb(S3C2410_ALMSEC
);
180 alm_tm
->tm_min
= readb(S3C2410_ALMMIN
);
181 alm_tm
->tm_hour
= readb(S3C2410_ALMHOUR
);
182 alm_tm
->tm_mon
= readb(S3C2410_ALMMON
);
183 alm_tm
->tm_mday
= readb(S3C2410_ALMDATE
);
184 alm_tm
->tm_year
= readb(S3C2410_ALMYEAR
);
186 alm_en
= readb(S3C2410_RTCALM
);
188 pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
190 alm_tm
->tm_year
, alm_tm
->tm_mon
, alm_tm
->tm_mday
,
191 alm_tm
->tm_hour
, alm_tm
->tm_min
, alm_tm
->tm_sec
);
194 /* decode the alarm enable field */
196 if (alm_en
& S3C2410_RTCALM_SECEN
) {
197 BCD_TO_BIN(alm_tm
->tm_sec
);
199 alm_tm
->tm_sec
= 0xff;
202 if (alm_en
& S3C2410_RTCALM_MINEN
) {
203 BCD_TO_BIN(alm_tm
->tm_min
);
205 alm_tm
->tm_min
= 0xff;
208 if (alm_en
& S3C2410_RTCALM_HOUREN
) {
209 BCD_TO_BIN(alm_tm
->tm_hour
);
211 alm_tm
->tm_hour
= 0xff;
214 if (alm_en
& S3C2410_RTCALM_DAYEN
) {
215 BCD_TO_BIN(alm_tm
->tm_mday
);
217 alm_tm
->tm_mday
= 0xff;
220 if (alm_en
& S3C2410_RTCALM_MONEN
) {
221 BCD_TO_BIN(alm_tm
->tm_mon
);
224 alm_tm
->tm_mon
= 0xff;
227 if (alm_en
& S3C2410_RTCALM_YEAREN
) {
228 BCD_TO_BIN(alm_tm
->tm_year
);
230 alm_tm
->tm_year
= 0xffff;
233 /* todo - set alrm->enabled ? */
236 static int s3c2410_rtc_setalarm(struct rtc_wkalrm
*alrm
)
238 struct rtc_time
*tm
= &alrm
->time
;
239 unsigned int alrm_en
;
241 pr_debug("s3c2410_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
243 tm
->tm_mday
& 0xff, tm
->tm_mon
& 0xff, tm
->tm_year
& 0xff,
244 tm
->tm_hour
& 0xff, tm
->tm_min
& 0xff, tm
->tm_sec
);
246 if (alrm
->enabled
|| 1) {
247 alrm_en
= readb(S3C2410_RTCALM
) & S3C2410_RTCALM_ALMEN
;
248 writeb(0x00, S3C2410_RTCALM
);
250 if (tm
->tm_sec
< 60 && tm
->tm_sec
>= 0) {
251 alrm_en
|= S3C2410_RTCALM_SECEN
;
252 writeb(BIN2BCD(tm
->tm_sec
), S3C2410_ALMSEC
);
255 if (tm
->tm_min
< 60 && tm
->tm_min
>= 0) {
256 alrm_en
|= S3C2410_RTCALM_MINEN
;
257 writeb(BIN2BCD(tm
->tm_min
), S3C2410_ALMMIN
);
260 if (tm
->tm_hour
< 24 && tm
->tm_hour
>= 0) {
261 alrm_en
|= S3C2410_RTCALM_HOUREN
;
262 writeb(BIN2BCD(tm
->tm_hour
), S3C2410_ALMHOUR
);
265 pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en
);
267 writeb(alrm_en
, S3C2410_RTCALM
);
268 enable_irq_wake(s3c2410_rtc_alarmno
);
270 alrm_en
= readb(S3C2410_RTCALM
);
271 alrm_en
&= ~S3C2410_RTCALM_ALMEN
;
272 writeb(alrm_en
, S3C2410_RTCALM
);
273 disable_irq_wake(s3c2410_rtc_alarmno
);
279 static int s3c2410_rtc_ioctl(unsigned int cmd
, unsigned long arg
)
284 s3c2410_rtc_setaie((cmd
== RTC_AIE_ON
) ? 1 : 0);
289 s3c2410_rtc_setpie((cmd
== RTC_PIE_ON
) ? 1 : 0);
293 return put_user(s3c2410_rtc_freq
, (unsigned long __user
*)arg
);
296 if (arg
< 1 || arg
> 64)
299 if (!capable(CAP_SYS_RESOURCE
))
302 /* check for power of 2 */
304 if ((arg
& (arg
-1)) != 0)
307 pr_debug("s3c2410_rtc: setting frequency %ld\n", arg
);
309 s3c2410_rtc_setfreq(arg
);
320 static int s3c2410_rtc_proc(char *buf
)
322 unsigned int rtcalm
= readb(S3C2410_RTCALM
);
323 unsigned int ticnt
= readb (S3C2410_TICNT
);
326 p
+= sprintf(p
, "alarm_IRQ\t: %s\n",
327 (rtcalm
& S3C2410_RTCALM_ALMEN
) ? "yes" : "no" );
328 p
+= sprintf(p
, "periodic_IRQ\t: %s\n",
329 (ticnt
& S3C2410_TICNT_ENABLE
) ? "yes" : "no" );
330 p
+= sprintf(p
, "periodic_freq\t: %d\n", s3c2410_rtc_freq
);
335 static int s3c2410_rtc_open(void)
339 ret
= request_irq(s3c2410_rtc_alarmno
, s3c2410_rtc_alarmirq
,
340 SA_INTERRUPT
, "s3c2410-rtc alarm", NULL
);
343 printk(KERN_ERR
"IRQ%d already in use\n", s3c2410_rtc_alarmno
);
345 ret
= request_irq(s3c2410_rtc_tickno
, s3c2410_rtc_tickirq
,
346 SA_INTERRUPT
, "s3c2410-rtc tick", NULL
);
349 printk(KERN_ERR
"IRQ%d already in use\n", s3c2410_rtc_tickno
);
356 free_irq(s3c2410_rtc_alarmno
, NULL
);
360 static void s3c2410_rtc_release(void)
362 /* do not clear AIE here, it may be needed for wake */
364 s3c2410_rtc_setpie(0);
365 free_irq(s3c2410_rtc_alarmno
, NULL
);
366 free_irq(s3c2410_rtc_tickno
, NULL
);
369 static struct rtc_ops s3c2410_rtcops
= {
370 .owner
= THIS_MODULE
,
371 .open
= s3c2410_rtc_open
,
372 .release
= s3c2410_rtc_release
,
373 .ioctl
= s3c2410_rtc_ioctl
,
374 .read_time
= s3c2410_rtc_gettime
,
375 .set_time
= s3c2410_rtc_settime
,
376 .read_alarm
= s3c2410_rtc_getalarm
,
377 .set_alarm
= s3c2410_rtc_setalarm
,
378 .proc
= s3c2410_rtc_proc
,
381 static void s3c2410_rtc_enable(struct device
*dev
, int en
)
385 if (s3c2410_rtc_base
== NULL
)
389 tmp
= readb(S3C2410_RTCCON
);
390 writeb(tmp
& ~S3C2410_RTCCON_RTCEN
, S3C2410_RTCCON
);
392 tmp
= readb(S3C2410_TICNT
);
393 writeb(tmp
& ~S3C2410_TICNT_ENABLE
, S3C2410_TICNT
);
395 /* re-enable the device, and check it is ok */
397 if ((readb(S3C2410_RTCCON
) & S3C2410_RTCCON_RTCEN
) == 0){
398 dev_info(dev
, "rtc disabled, re-enabling\n");
400 tmp
= readb(S3C2410_RTCCON
);
401 writeb(tmp
| S3C2410_RTCCON_RTCEN
, S3C2410_RTCCON
);
404 if ((readb(S3C2410_RTCCON
) & S3C2410_RTCCON_CNTSEL
)){
405 dev_info(dev
, "removing S3C2410_RTCCON_CNTSEL\n");
407 tmp
= readb(S3C2410_RTCCON
);
408 writeb(tmp
& ~S3C2410_RTCCON_CNTSEL
, S3C2410_RTCCON
);
411 if ((readb(S3C2410_RTCCON
) & S3C2410_RTCCON_CLKRST
)){
412 dev_info(dev
, "removing S3C2410_RTCCON_CLKRST\n");
414 tmp
= readb(S3C2410_RTCCON
);
415 writeb(tmp
& ~S3C2410_RTCCON_CLKRST
, S3C2410_RTCCON
);
420 static int s3c2410_rtc_remove(struct device
*dev
)
422 unregister_rtc(&s3c2410_rtcops
);
424 s3c2410_rtc_setpie(0);
425 s3c2410_rtc_setaie(0);
427 if (s3c2410_rtc_mem
!= NULL
) {
428 pr_debug("s3c2410_rtc: releasing s3c2410_rtc_mem\n");
429 iounmap(s3c2410_rtc_base
);
430 release_resource(s3c2410_rtc_mem
);
431 kfree(s3c2410_rtc_mem
);
437 static int s3c2410_rtc_probe(struct device
*dev
)
439 struct platform_device
*pdev
= to_platform_device(dev
);
440 struct resource
*res
;
443 pr_debug("%s: probe=%p, device=%p\n", __FUNCTION__
, pdev
, dev
);
447 s3c2410_rtc_tickno
= platform_get_irq(pdev
, 1);
448 if (s3c2410_rtc_tickno
<= 0) {
449 dev_err(dev
, "no irq for rtc tick\n");
453 s3c2410_rtc_alarmno
= platform_get_irq(pdev
, 0);
454 if (s3c2410_rtc_alarmno
<= 0) {
455 dev_err(dev
, "no irq for alarm\n");
459 pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
460 s3c2410_rtc_tickno
, s3c2410_rtc_alarmno
);
462 /* get the memory region */
464 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
466 dev_err(dev
, "failed to get memory region resource\n");
470 s3c2410_rtc_mem
= request_mem_region(res
->start
, res
->end
-res
->start
+1,
473 if (s3c2410_rtc_mem
== NULL
) {
474 dev_err(dev
, "failed to reserve memory region\n");
479 s3c2410_rtc_base
= ioremap(res
->start
, res
->end
- res
->start
+ 1);
480 if (s3c2410_rtc_base
== NULL
) {
481 dev_err(dev
, "failed ioremap()\n");
486 s3c2410_rtc_mem
= res
;
487 pr_debug("s3c2410_rtc_base=%p\n", s3c2410_rtc_base
);
489 pr_debug("s3c2410_rtc: RTCCON=%02x\n", readb(S3C2410_RTCCON
));
491 /* check to see if everything is setup correctly */
493 s3c2410_rtc_enable(dev
, 1);
495 pr_debug("s3c2410_rtc: RTCCON=%02x\n", readb(S3C2410_RTCCON
));
497 s3c2410_rtc_setfreq(s3c2410_rtc_freq
);
499 /* register RTC and exit */
501 register_rtc(&s3c2410_rtcops
);
505 dev_err(dev
, "error %d during initialisation\n", ret
);
512 /* S3C2410 RTC Power management control */
514 static struct timespec s3c2410_rtc_delta
;
516 static int ticnt_save
;
518 static int s3c2410_rtc_suspend(struct device
*dev
, pm_message_t state
, u32 level
)
521 struct timespec time
;
525 if (level
== SUSPEND_POWER_DOWN
) {
526 /* save TICNT for anyone using periodic interrupts */
528 ticnt_save
= readb(S3C2410_TICNT
);
530 /* calculate time delta for suspend */
532 s3c2410_rtc_gettime(&tm
);
533 rtc_tm_to_time(&tm
, &time
.tv_sec
);
534 save_time_delta(&s3c2410_rtc_delta
, &time
);
535 s3c2410_rtc_enable(dev
, 0);
541 static int s3c2410_rtc_resume(struct device
*dev
, u32 level
)
544 struct timespec time
;
548 s3c2410_rtc_enable(dev
, 1);
549 s3c2410_rtc_gettime(&tm
);
550 rtc_tm_to_time(&tm
, &time
.tv_sec
);
551 restore_time_delta(&s3c2410_rtc_delta
, &time
);
553 writeb(ticnt_save
, S3C2410_TICNT
);
557 #define s3c2410_rtc_suspend NULL
558 #define s3c2410_rtc_resume NULL
561 static struct device_driver s3c2410_rtcdrv
= {
562 .name
= "s3c2410-rtc",
563 .bus
= &platform_bus_type
,
564 .probe
= s3c2410_rtc_probe
,
565 .remove
= s3c2410_rtc_remove
,
566 .suspend
= s3c2410_rtc_suspend
,
567 .resume
= s3c2410_rtc_resume
,
570 static char __initdata banner
[] = "S3C2410 RTC, (c) 2004 Simtec Electronics\n";
572 static int __init
s3c2410_rtc_init(void)
575 return driver_register(&s3c2410_rtcdrv
);
578 static void __exit
s3c2410_rtc_exit(void)
580 driver_unregister(&s3c2410_rtcdrv
);
583 module_init(s3c2410_rtc_init
);
584 module_exit(s3c2410_rtc_exit
);
586 MODULE_DESCRIPTION("S3C24XX RTC Driver");
587 MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
588 MODULE_LICENSE("GPL");