2 * Real Time Clock interface for Linux on Atmel AT91RM9200
4 * Copyright (C) 2002 Rick Bronson
6 * Converted to RTC class model by Andrew Victor
8 * Ported to Linux 2.6 by Steven Scholz
9 * Based on s3c2410-rtc.c Simtec Electronics
11 * Based on sa1100-rtc.c by Nils Faerber
12 * Based on rtc.c by Paul Gortmaker
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version
17 * 2 of the License, or (at your option) any later version.
21 #include <linux/module.h>
22 #include <linux/kernel.h>
23 #include <linux/platform_device.h>
24 #include <linux/time.h>
25 #include <linux/rtc.h>
26 #include <linux/bcd.h>
27 #include <linux/interrupt.h>
28 #include <linux/spinlock.h>
29 #include <linux/ioctl.h>
30 #include <linux/completion.h>
33 #include <linux/of_device.h>
35 #include <asm/uaccess.h>
37 #include "rtc-at91rm9200.h"
39 #define at91_rtc_read(field) \
40 __raw_readl(at91_rtc_regs + field)
41 #define at91_rtc_write(field, val) \
42 __raw_writel((val), at91_rtc_regs + field)
44 #define AT91_RTC_EPOCH 1900UL /* just like arch/arm/common/rtctime.c */
46 struct at91_rtc_config
{
50 static const struct at91_rtc_config
*at91_rtc_config
;
51 static DECLARE_COMPLETION(at91_rtc_updated
);
52 static unsigned int at91_alarm_year
= AT91_RTC_EPOCH
;
53 static void __iomem
*at91_rtc_regs
;
55 static DEFINE_SPINLOCK(at91_rtc_lock
);
56 static u32 at91_rtc_shadow_imr
;
58 static void at91_rtc_write_ier(u32 mask
)
62 spin_lock_irqsave(&at91_rtc_lock
, flags
);
63 at91_rtc_shadow_imr
|= mask
;
64 at91_rtc_write(AT91_RTC_IER
, mask
);
65 spin_unlock_irqrestore(&at91_rtc_lock
, flags
);
68 static void at91_rtc_write_idr(u32 mask
)
72 spin_lock_irqsave(&at91_rtc_lock
, flags
);
73 at91_rtc_write(AT91_RTC_IDR
, mask
);
75 * Register read back (of any RTC-register) needed to make sure
76 * IDR-register write has reached the peripheral before updating
79 * Note that there is still a possibility that the mask is updated
80 * before interrupts have actually been disabled in hardware. The only
81 * way to be certain would be to poll the IMR-register, which is is
82 * the very register we are trying to emulate. The register read back
83 * is a reasonable heuristic.
85 at91_rtc_read(AT91_RTC_SR
);
86 at91_rtc_shadow_imr
&= ~mask
;
87 spin_unlock_irqrestore(&at91_rtc_lock
, flags
);
90 static u32
at91_rtc_read_imr(void)
95 if (at91_rtc_config
->use_shadow_imr
) {
96 spin_lock_irqsave(&at91_rtc_lock
, flags
);
97 mask
= at91_rtc_shadow_imr
;
98 spin_unlock_irqrestore(&at91_rtc_lock
, flags
);
100 mask
= at91_rtc_read(AT91_RTC_IMR
);
107 * Decode time/date into rtc_time structure
109 static void at91_rtc_decodetime(unsigned int timereg
, unsigned int calreg
,
112 unsigned int time
, date
;
114 /* must read twice in case it changes */
116 time
= at91_rtc_read(timereg
);
117 date
= at91_rtc_read(calreg
);
118 } while ((time
!= at91_rtc_read(timereg
)) ||
119 (date
!= at91_rtc_read(calreg
)));
121 tm
->tm_sec
= bcd2bin((time
& AT91_RTC_SEC
) >> 0);
122 tm
->tm_min
= bcd2bin((time
& AT91_RTC_MIN
) >> 8);
123 tm
->tm_hour
= bcd2bin((time
& AT91_RTC_HOUR
) >> 16);
126 * The Calendar Alarm register does not have a field for
127 * the year - so these will return an invalid value. When an
128 * alarm is set, at91_alarm_year will store the current year.
130 tm
->tm_year
= bcd2bin(date
& AT91_RTC_CENT
) * 100; /* century */
131 tm
->tm_year
+= bcd2bin((date
& AT91_RTC_YEAR
) >> 8); /* year */
133 tm
->tm_wday
= bcd2bin((date
& AT91_RTC_DAY
) >> 21) - 1; /* day of the week [0-6], Sunday=0 */
134 tm
->tm_mon
= bcd2bin((date
& AT91_RTC_MONTH
) >> 16) - 1;
135 tm
->tm_mday
= bcd2bin((date
& AT91_RTC_DATE
) >> 24);
139 * Read current time and date in RTC
141 static int at91_rtc_readtime(struct device
*dev
, struct rtc_time
*tm
)
143 at91_rtc_decodetime(AT91_RTC_TIMR
, AT91_RTC_CALR
, tm
);
144 tm
->tm_yday
= rtc_year_days(tm
->tm_mday
, tm
->tm_mon
, tm
->tm_year
);
145 tm
->tm_year
= tm
->tm_year
- 1900;
147 dev_dbg(dev
, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__
,
148 1900 + tm
->tm_year
, tm
->tm_mon
, tm
->tm_mday
,
149 tm
->tm_hour
, tm
->tm_min
, tm
->tm_sec
);
155 * Set current time and date in RTC
157 static int at91_rtc_settime(struct device
*dev
, struct rtc_time
*tm
)
161 dev_dbg(dev
, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__
,
162 1900 + tm
->tm_year
, tm
->tm_mon
, tm
->tm_mday
,
163 tm
->tm_hour
, tm
->tm_min
, tm
->tm_sec
);
165 /* Stop Time/Calendar from counting */
166 cr
= at91_rtc_read(AT91_RTC_CR
);
167 at91_rtc_write(AT91_RTC_CR
, cr
| AT91_RTC_UPDCAL
| AT91_RTC_UPDTIM
);
169 at91_rtc_write_ier(AT91_RTC_ACKUPD
);
170 wait_for_completion(&at91_rtc_updated
); /* wait for ACKUPD interrupt */
171 at91_rtc_write_idr(AT91_RTC_ACKUPD
);
173 at91_rtc_write(AT91_RTC_TIMR
,
174 bin2bcd(tm
->tm_sec
) << 0
175 | bin2bcd(tm
->tm_min
) << 8
176 | bin2bcd(tm
->tm_hour
) << 16);
178 at91_rtc_write(AT91_RTC_CALR
,
179 bin2bcd((tm
->tm_year
+ 1900) / 100) /* century */
180 | bin2bcd(tm
->tm_year
% 100) << 8 /* year */
181 | bin2bcd(tm
->tm_mon
+ 1) << 16 /* tm_mon starts at zero */
182 | bin2bcd(tm
->tm_wday
+ 1) << 21 /* day of the week [0-6], Sunday=0 */
183 | bin2bcd(tm
->tm_mday
) << 24);
185 /* Restart Time/Calendar */
186 cr
= at91_rtc_read(AT91_RTC_CR
);
187 at91_rtc_write(AT91_RTC_CR
, cr
& ~(AT91_RTC_UPDCAL
| AT91_RTC_UPDTIM
));
193 * Read alarm time and date in RTC
195 static int at91_rtc_readalarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
197 struct rtc_time
*tm
= &alrm
->time
;
199 at91_rtc_decodetime(AT91_RTC_TIMALR
, AT91_RTC_CALALR
, tm
);
200 tm
->tm_yday
= rtc_year_days(tm
->tm_mday
, tm
->tm_mon
, tm
->tm_year
);
201 tm
->tm_year
= at91_alarm_year
- 1900;
203 alrm
->enabled
= (at91_rtc_read_imr() & AT91_RTC_ALARM
)
206 dev_dbg(dev
, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__
,
207 1900 + tm
->tm_year
, tm
->tm_mon
, tm
->tm_mday
,
208 tm
->tm_hour
, tm
->tm_min
, tm
->tm_sec
);
214 * Set alarm time and date in RTC
216 static int at91_rtc_setalarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
220 at91_rtc_decodetime(AT91_RTC_TIMR
, AT91_RTC_CALR
, &tm
);
222 at91_alarm_year
= tm
.tm_year
;
224 tm
.tm_hour
= alrm
->time
.tm_hour
;
225 tm
.tm_min
= alrm
->time
.tm_min
;
226 tm
.tm_sec
= alrm
->time
.tm_sec
;
228 at91_rtc_write_idr(AT91_RTC_ALARM
);
229 at91_rtc_write(AT91_RTC_TIMALR
,
230 bin2bcd(tm
.tm_sec
) << 0
231 | bin2bcd(tm
.tm_min
) << 8
232 | bin2bcd(tm
.tm_hour
) << 16
233 | AT91_RTC_HOUREN
| AT91_RTC_MINEN
| AT91_RTC_SECEN
);
234 at91_rtc_write(AT91_RTC_CALALR
,
235 bin2bcd(tm
.tm_mon
+ 1) << 16 /* tm_mon starts at zero */
236 | bin2bcd(tm
.tm_mday
) << 24
237 | AT91_RTC_DATEEN
| AT91_RTC_MTHEN
);
240 at91_rtc_write(AT91_RTC_SCCR
, AT91_RTC_ALARM
);
241 at91_rtc_write_ier(AT91_RTC_ALARM
);
244 dev_dbg(dev
, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__
,
245 at91_alarm_year
, tm
.tm_mon
, tm
.tm_mday
, tm
.tm_hour
,
246 tm
.tm_min
, tm
.tm_sec
);
251 static int at91_rtc_alarm_irq_enable(struct device
*dev
, unsigned int enabled
)
253 dev_dbg(dev
, "%s(): cmd=%08x\n", __func__
, enabled
);
256 at91_rtc_write(AT91_RTC_SCCR
, AT91_RTC_ALARM
);
257 at91_rtc_write_ier(AT91_RTC_ALARM
);
259 at91_rtc_write_idr(AT91_RTC_ALARM
);
264 * Provide additional RTC information in /proc/driver/rtc
266 static int at91_rtc_proc(struct device
*dev
, struct seq_file
*seq
)
268 unsigned long imr
= at91_rtc_read_imr();
270 seq_printf(seq
, "update_IRQ\t: %s\n",
271 (imr
& AT91_RTC_ACKUPD
) ? "yes" : "no");
272 seq_printf(seq
, "periodic_IRQ\t: %s\n",
273 (imr
& AT91_RTC_SECEV
) ? "yes" : "no");
279 * IRQ handler for the RTC
281 static irqreturn_t
at91_rtc_interrupt(int irq
, void *dev_id
)
283 struct platform_device
*pdev
= dev_id
;
284 struct rtc_device
*rtc
= platform_get_drvdata(pdev
);
286 unsigned long events
= 0;
288 rtsr
= at91_rtc_read(AT91_RTC_SR
) & at91_rtc_read_imr();
289 if (rtsr
) { /* this interrupt is shared! Is it ours? */
290 if (rtsr
& AT91_RTC_ALARM
)
291 events
|= (RTC_AF
| RTC_IRQF
);
292 if (rtsr
& AT91_RTC_SECEV
)
293 events
|= (RTC_UF
| RTC_IRQF
);
294 if (rtsr
& AT91_RTC_ACKUPD
)
295 complete(&at91_rtc_updated
);
297 at91_rtc_write(AT91_RTC_SCCR
, rtsr
); /* clear status reg */
299 rtc_update_irq(rtc
, 1, events
);
301 dev_dbg(&pdev
->dev
, "%s(): num=%ld, events=0x%02lx\n", __func__
,
302 events
>> 8, events
& 0x000000FF);
306 return IRQ_NONE
; /* not handled */
309 static const struct at91_rtc_config at91rm9200_config
= {
312 static const struct at91_rtc_config at91sam9x5_config
= {
313 .use_shadow_imr
= true,
317 static const struct of_device_id at91_rtc_dt_ids
[] = {
319 .compatible
= "atmel,at91rm9200-rtc",
320 .data
= &at91rm9200_config
,
322 .compatible
= "atmel,at91sam9x5-rtc",
323 .data
= &at91sam9x5_config
,
328 MODULE_DEVICE_TABLE(of
, at91_rtc_dt_ids
);
331 static const struct at91_rtc_config
*
332 at91_rtc_get_config(struct platform_device
*pdev
)
334 const struct of_device_id
*match
;
336 if (pdev
->dev
.of_node
) {
337 match
= of_match_node(at91_rtc_dt_ids
, pdev
->dev
.of_node
);
340 return (const struct at91_rtc_config
*)match
->data
;
343 return &at91rm9200_config
;
346 static const struct rtc_class_ops at91_rtc_ops
= {
347 .read_time
= at91_rtc_readtime
,
348 .set_time
= at91_rtc_settime
,
349 .read_alarm
= at91_rtc_readalarm
,
350 .set_alarm
= at91_rtc_setalarm
,
351 .proc
= at91_rtc_proc
,
352 .alarm_irq_enable
= at91_rtc_alarm_irq_enable
,
356 * Initialize and install RTC driver
358 static int __init
at91_rtc_probe(struct platform_device
*pdev
)
360 struct rtc_device
*rtc
;
361 struct resource
*regs
;
364 at91_rtc_config
= at91_rtc_get_config(pdev
);
365 if (!at91_rtc_config
)
368 regs
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
370 dev_err(&pdev
->dev
, "no mmio resource defined\n");
374 irq
= platform_get_irq(pdev
, 0);
376 dev_err(&pdev
->dev
, "no irq resource defined\n");
380 at91_rtc_regs
= ioremap(regs
->start
, resource_size(regs
));
381 if (!at91_rtc_regs
) {
382 dev_err(&pdev
->dev
, "failed to map registers, aborting.\n");
386 at91_rtc_write(AT91_RTC_CR
, 0);
387 at91_rtc_write(AT91_RTC_MR
, 0); /* 24 hour mode */
389 /* Disable all interrupts */
390 at91_rtc_write_idr(AT91_RTC_ACKUPD
| AT91_RTC_ALARM
|
391 AT91_RTC_SECEV
| AT91_RTC_TIMEV
|
394 ret
= request_irq(irq
, at91_rtc_interrupt
,
398 dev_err(&pdev
->dev
, "IRQ %d already in use.\n", irq
);
402 /* cpu init code should really have flagged this device as
403 * being wake-capable; if it didn't, do that here.
405 if (!device_can_wakeup(&pdev
->dev
))
406 device_init_wakeup(&pdev
->dev
, 1);
408 rtc
= rtc_device_register(pdev
->name
, &pdev
->dev
,
409 &at91_rtc_ops
, THIS_MODULE
);
414 platform_set_drvdata(pdev
, rtc
);
416 dev_info(&pdev
->dev
, "AT91 Real Time Clock driver.\n");
422 iounmap(at91_rtc_regs
);
428 * Disable and remove the RTC driver
430 static int __exit
at91_rtc_remove(struct platform_device
*pdev
)
432 struct rtc_device
*rtc
= platform_get_drvdata(pdev
);
434 /* Disable all interrupts */
435 at91_rtc_write_idr(AT91_RTC_ACKUPD
| AT91_RTC_ALARM
|
436 AT91_RTC_SECEV
| AT91_RTC_TIMEV
|
440 rtc_device_unregister(rtc
);
441 iounmap(at91_rtc_regs
);
442 platform_set_drvdata(pdev
, NULL
);
447 #ifdef CONFIG_PM_SLEEP
449 /* AT91RM9200 RTC Power management control */
451 static u32 at91_rtc_imr
;
453 static int at91_rtc_suspend(struct device
*dev
)
455 /* this IRQ is shared with DBGU and other hardware which isn't
456 * necessarily doing PM like we are...
458 at91_rtc_imr
= at91_rtc_read_imr()
459 & (AT91_RTC_ALARM
|AT91_RTC_SECEV
);
461 if (device_may_wakeup(dev
))
462 enable_irq_wake(irq
);
464 at91_rtc_write_idr(at91_rtc_imr
);
469 static int at91_rtc_resume(struct device
*dev
)
472 if (device_may_wakeup(dev
))
473 disable_irq_wake(irq
);
475 at91_rtc_write_ier(at91_rtc_imr
);
481 static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops
, at91_rtc_suspend
, at91_rtc_resume
);
483 static struct platform_driver at91_rtc_driver
= {
484 .remove
= __exit_p(at91_rtc_remove
),
487 .owner
= THIS_MODULE
,
488 .pm
= &at91_rtc_pm_ops
,
489 .of_match_table
= of_match_ptr(at91_rtc_dt_ids
),
493 module_platform_driver_probe(at91_rtc_driver
, at91_rtc_probe
);
495 MODULE_AUTHOR("Rick Bronson");
496 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
497 MODULE_LICENSE("GPL");
498 MODULE_ALIAS("platform:at91_rtc");