2 * drivers/rtc/rtc-spear.c
4 * Copyright (C) 2010 ST Microelectronics
5 * Rajeev Kumar<rajeev-dlh.kumar@st.com>
7 * This file is licensed under the terms of the GNU General Public
8 * License version 2. This program is licensed "as is" without any
9 * warranty of any kind, whether express or implied.
12 #include <linux/bcd.h>
13 #include <linux/clk.h>
14 #include <linux/delay.h>
15 #include <linux/init.h>
17 #include <linux/irq.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/rtc.h>
21 #include <linux/slab.h>
22 #include <linux/spinlock.h>
27 #define ALARM_TIME_REG 0x08
28 #define ALARM_DATE_REG 0x0C
30 #define STATUS_REG 0x14
32 /* TIME_REG & ALARM_TIME_REG */
33 #define SECONDS_UNITS (0xf<<0) /* seconds units position */
34 #define SECONDS_TENS (0x7<<4) /* seconds tens position */
35 #define MINUTES_UNITS (0xf<<8) /* minutes units position */
36 #define MINUTES_TENS (0x7<<12) /* minutes tens position */
37 #define HOURS_UNITS (0xf<<16) /* hours units position */
38 #define HOURS_TENS (0x3<<20) /* hours tens position */
40 /* DATE_REG & ALARM_DATE_REG */
41 #define DAYS_UNITS (0xf<<0) /* days units position */
42 #define DAYS_TENS (0x3<<4) /* days tens position */
43 #define MONTHS_UNITS (0xf<<8) /* months units position */
44 #define MONTHS_TENS (0x1<<12) /* months tens position */
45 #define YEARS_UNITS (0xf<<16) /* years units position */
46 #define YEARS_TENS (0xf<<20) /* years tens position */
47 #define YEARS_HUNDREDS (0xf<<24) /* years hundereds position */
48 #define YEARS_MILLENIUMS (0xf<<28) /* years millenium position */
50 /* MASK SHIFT TIME_REG & ALARM_TIME_REG*/
51 #define SECOND_SHIFT 0x00 /* seconds units */
52 #define MINUTE_SHIFT 0x08 /* minutes units position */
53 #define HOUR_SHIFT 0x10 /* hours units position */
54 #define MDAY_SHIFT 0x00 /* Month day shift */
55 #define MONTH_SHIFT 0x08 /* Month shift */
56 #define YEAR_SHIFT 0x10 /* Year shift */
58 #define SECOND_MASK 0x7F
60 #define HOUR_MASK 0x3F
62 #define MONTH_MASK 0x7F
63 #define YEAR_MASK 0xFFFF
65 /* date reg equal to time reg, for debug only */
66 #define TIME_BYP (1<<9)
67 #define INT_ENABLE (1<<31) /* interrupt enable */
70 #define CLK_UNCONNECTED (1<<0)
71 #define PEND_WR_TIME (1<<2)
72 #define PEND_WR_DATE (1<<3)
73 #define LOST_WR_TIME (1<<4)
74 #define LOST_WR_DATE (1<<5)
75 #define RTC_INT_MASK (1<<31)
76 #define STATUS_BUSY (PEND_WR_TIME | PEND_WR_DATE)
77 #define STATUS_FAIL (LOST_WR_TIME | LOST_WR_DATE)
79 struct spear_rtc_config
{
85 static inline void spear_rtc_clear_interrupt(struct spear_rtc_config
*config
)
90 spin_lock_irqsave(&config
->lock
, flags
);
91 val
= readl(config
->ioaddr
+ STATUS_REG
);
93 writel(val
, config
->ioaddr
+ STATUS_REG
);
94 spin_unlock_irqrestore(&config
->lock
, flags
);
97 static inline void spear_rtc_enable_interrupt(struct spear_rtc_config
*config
)
101 val
= readl(config
->ioaddr
+ CTRL_REG
);
102 if (!(val
& INT_ENABLE
)) {
103 spear_rtc_clear_interrupt(config
);
105 writel(val
, config
->ioaddr
+ CTRL_REG
);
109 static inline void spear_rtc_disable_interrupt(struct spear_rtc_config
*config
)
113 val
= readl(config
->ioaddr
+ CTRL_REG
);
114 if (val
& INT_ENABLE
) {
116 writel(val
, config
->ioaddr
+ CTRL_REG
);
120 static inline int is_write_complete(struct spear_rtc_config
*config
)
125 spin_lock_irqsave(&config
->lock
, flags
);
126 if ((readl(config
->ioaddr
+ STATUS_REG
)) & STATUS_FAIL
)
128 spin_unlock_irqrestore(&config
->lock
, flags
);
133 static void rtc_wait_not_busy(struct spear_rtc_config
*config
)
135 int status
, count
= 0;
138 /* Assuming BUSY may stay active for 80 msec) */
139 for (count
= 0; count
< 80; count
++) {
140 spin_lock_irqsave(&config
->lock
, flags
);
141 status
= readl(config
->ioaddr
+ STATUS_REG
);
142 spin_unlock_irqrestore(&config
->lock
, flags
);
143 if ((status
& STATUS_BUSY
) == 0)
145 /* check status busy, after each msec */
150 static irqreturn_t
spear_rtc_irq(int irq
, void *dev_id
)
152 struct rtc_device
*rtc
= (struct rtc_device
*)dev_id
;
153 struct spear_rtc_config
*config
= dev_get_drvdata(&rtc
->dev
);
154 unsigned long flags
, events
= 0;
155 unsigned int irq_data
;
157 spin_lock_irqsave(&config
->lock
, flags
);
158 irq_data
= readl(config
->ioaddr
+ STATUS_REG
);
159 spin_unlock_irqrestore(&config
->lock
, flags
);
161 if ((irq_data
& RTC_INT_MASK
)) {
162 spear_rtc_clear_interrupt(config
);
163 events
= RTC_IRQF
| RTC_AF
;
164 rtc_update_irq(rtc
, 1, events
);
171 static int tm2bcd(struct rtc_time
*tm
)
173 if (rtc_valid_tm(tm
) != 0)
175 tm
->tm_sec
= bin2bcd(tm
->tm_sec
);
176 tm
->tm_min
= bin2bcd(tm
->tm_min
);
177 tm
->tm_hour
= bin2bcd(tm
->tm_hour
);
178 tm
->tm_mday
= bin2bcd(tm
->tm_mday
);
179 tm
->tm_mon
= bin2bcd(tm
->tm_mon
+ 1);
180 tm
->tm_year
= bin2bcd(tm
->tm_year
);
185 static void bcd2tm(struct rtc_time
*tm
)
187 tm
->tm_sec
= bcd2bin(tm
->tm_sec
);
188 tm
->tm_min
= bcd2bin(tm
->tm_min
);
189 tm
->tm_hour
= bcd2bin(tm
->tm_hour
);
190 tm
->tm_mday
= bcd2bin(tm
->tm_mday
);
191 tm
->tm_mon
= bcd2bin(tm
->tm_mon
) - 1;
193 tm
->tm_year
= bcd2bin(tm
->tm_year
);
197 * spear_rtc_read_time - set the time
198 * @dev: rtc device in use
199 * @tm: holds date and time
201 * This function read time and date. On success it will return 0
202 * otherwise -ve error is returned.
204 static int spear_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
206 struct platform_device
*pdev
= to_platform_device(dev
);
207 struct rtc_device
*rtc
= platform_get_drvdata(pdev
);
208 struct spear_rtc_config
*config
= dev_get_drvdata(&rtc
->dev
);
209 unsigned int time
, date
;
211 /* we don't report wday/yday/isdst ... */
212 rtc_wait_not_busy(config
);
214 time
= readl(config
->ioaddr
+ TIME_REG
);
215 date
= readl(config
->ioaddr
+ DATE_REG
);
216 tm
->tm_sec
= (time
>> SECOND_SHIFT
) & SECOND_MASK
;
217 tm
->tm_min
= (time
>> MINUTE_SHIFT
) & MIN_MASK
;
218 tm
->tm_hour
= (time
>> HOUR_SHIFT
) & HOUR_MASK
;
219 tm
->tm_mday
= (date
>> MDAY_SHIFT
) & DAY_MASK
;
220 tm
->tm_mon
= (date
>> MONTH_SHIFT
) & MONTH_MASK
;
221 tm
->tm_year
= (date
>> YEAR_SHIFT
) & YEAR_MASK
;
228 * spear_rtc_set_time - set the time
229 * @dev: rtc device in use
230 * @tm: holds date and time
232 * This function set time and date. On success it will return 0
233 * otherwise -ve error is returned.
235 static int spear_rtc_set_time(struct device
*dev
, struct rtc_time
*tm
)
237 struct platform_device
*pdev
= to_platform_device(dev
);
238 struct rtc_device
*rtc
= platform_get_drvdata(pdev
);
239 struct spear_rtc_config
*config
= dev_get_drvdata(&rtc
->dev
);
240 unsigned int time
, date
, err
= 0;
245 rtc_wait_not_busy(config
);
246 time
= (tm
->tm_sec
<< SECOND_SHIFT
) | (tm
->tm_min
<< MINUTE_SHIFT
) |
247 (tm
->tm_hour
<< HOUR_SHIFT
);
248 date
= (tm
->tm_mday
<< MDAY_SHIFT
) | (tm
->tm_mon
<< MONTH_SHIFT
) |
249 (tm
->tm_year
<< YEAR_SHIFT
);
250 writel(time
, config
->ioaddr
+ TIME_REG
);
251 writel(date
, config
->ioaddr
+ DATE_REG
);
252 err
= is_write_complete(config
);
260 * spear_rtc_read_alarm - read the alarm time
261 * @dev: rtc device in use
262 * @alm: holds alarm date and time
264 * This function read alarm time and date. On success it will return 0
265 * otherwise -ve error is returned.
267 static int spear_rtc_read_alarm(struct device
*dev
, struct rtc_wkalrm
*alm
)
269 struct platform_device
*pdev
= to_platform_device(dev
);
270 struct rtc_device
*rtc
= platform_get_drvdata(pdev
);
271 struct spear_rtc_config
*config
= dev_get_drvdata(&rtc
->dev
);
272 unsigned int time
, date
;
274 rtc_wait_not_busy(config
);
276 time
= readl(config
->ioaddr
+ ALARM_TIME_REG
);
277 date
= readl(config
->ioaddr
+ ALARM_DATE_REG
);
278 alm
->time
.tm_sec
= (time
>> SECOND_SHIFT
) & SECOND_MASK
;
279 alm
->time
.tm_min
= (time
>> MINUTE_SHIFT
) & MIN_MASK
;
280 alm
->time
.tm_hour
= (time
>> HOUR_SHIFT
) & HOUR_MASK
;
281 alm
->time
.tm_mday
= (date
>> MDAY_SHIFT
) & DAY_MASK
;
282 alm
->time
.tm_mon
= (date
>> MONTH_SHIFT
) & MONTH_MASK
;
283 alm
->time
.tm_year
= (date
>> YEAR_SHIFT
) & YEAR_MASK
;
286 alm
->enabled
= readl(config
->ioaddr
+ CTRL_REG
) & INT_ENABLE
;
292 * spear_rtc_set_alarm - set the alarm time
293 * @dev: rtc device in use
294 * @alm: holds alarm date and time
296 * This function set alarm time and date. On success it will return 0
297 * otherwise -ve error is returned.
299 static int spear_rtc_set_alarm(struct device
*dev
, struct rtc_wkalrm
*alm
)
301 struct platform_device
*pdev
= to_platform_device(dev
);
302 struct rtc_device
*rtc
= platform_get_drvdata(pdev
);
303 struct spear_rtc_config
*config
= dev_get_drvdata(&rtc
->dev
);
304 unsigned int time
, date
, err
= 0;
306 if (tm2bcd(&alm
->time
) < 0)
309 rtc_wait_not_busy(config
);
311 time
= (alm
->time
.tm_sec
<< SECOND_SHIFT
) | (alm
->time
.tm_min
<<
312 MINUTE_SHIFT
) | (alm
->time
.tm_hour
<< HOUR_SHIFT
);
313 date
= (alm
->time
.tm_mday
<< MDAY_SHIFT
) | (alm
->time
.tm_mon
<<
314 MONTH_SHIFT
) | (alm
->time
.tm_year
<< YEAR_SHIFT
);
316 writel(time
, config
->ioaddr
+ ALARM_TIME_REG
);
317 writel(date
, config
->ioaddr
+ ALARM_DATE_REG
);
318 err
= is_write_complete(config
);
323 spear_rtc_enable_interrupt(config
);
325 spear_rtc_disable_interrupt(config
);
329 static struct rtc_class_ops spear_rtc_ops
= {
330 .read_time
= spear_rtc_read_time
,
331 .set_time
= spear_rtc_set_time
,
332 .read_alarm
= spear_rtc_read_alarm
,
333 .set_alarm
= spear_rtc_set_alarm
,
336 static int __devinit
spear_rtc_probe(struct platform_device
*pdev
)
338 struct resource
*res
;
339 struct rtc_device
*rtc
;
340 struct spear_rtc_config
*config
;
341 unsigned int status
= 0;
344 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
346 dev_err(&pdev
->dev
, "no resource defined\n");
349 if (!request_mem_region(res
->start
, resource_size(res
), pdev
->name
)) {
350 dev_err(&pdev
->dev
, "rtc region already claimed\n");
354 config
= kzalloc(sizeof(*config
), GFP_KERNEL
);
356 dev_err(&pdev
->dev
, "out of memory\n");
358 goto err_release_region
;
361 config
->clk
= clk_get(&pdev
->dev
, NULL
);
362 if (IS_ERR(config
->clk
)) {
363 status
= PTR_ERR(config
->clk
);
367 status
= clk_enable(config
->clk
);
371 config
->ioaddr
= ioremap(res
->start
, resource_size(res
));
372 if (!config
->ioaddr
) {
373 dev_err(&pdev
->dev
, "ioremap fail\n");
375 goto err_disable_clock
;
378 spin_lock_init(&config
->lock
);
380 rtc
= rtc_device_register(pdev
->name
, &pdev
->dev
, &spear_rtc_ops
,
383 dev_err(&pdev
->dev
, "can't register RTC device, err %ld\n",
385 status
= PTR_ERR(rtc
);
389 platform_set_drvdata(pdev
, rtc
);
390 dev_set_drvdata(&rtc
->dev
, config
);
393 irq
= platform_get_irq(pdev
, 0);
395 dev_err(&pdev
->dev
, "no update irq?\n");
397 goto err_clear_platdata
;
400 status
= request_irq(irq
, spear_rtc_irq
, 0, pdev
->name
, rtc
);
402 dev_err(&pdev
->dev
, "Alarm interrupt IRQ%d already \
404 goto err_clear_platdata
;
407 if (!device_can_wakeup(&pdev
->dev
))
408 device_init_wakeup(&pdev
->dev
, 1);
413 platform_set_drvdata(pdev
, NULL
);
414 dev_set_drvdata(&rtc
->dev
, NULL
);
415 rtc_device_unregister(rtc
);
417 iounmap(config
->ioaddr
);
419 clk_disable(config
->clk
);
421 clk_put(config
->clk
);
425 release_mem_region(res
->start
, resource_size(res
));
430 static int __devexit
spear_rtc_remove(struct platform_device
*pdev
)
432 struct rtc_device
*rtc
= platform_get_drvdata(pdev
);
433 struct spear_rtc_config
*config
= dev_get_drvdata(&rtc
->dev
);
435 struct resource
*res
;
437 /* leave rtc running, but disable irqs */
438 spear_rtc_disable_interrupt(config
);
439 device_init_wakeup(&pdev
->dev
, 0);
440 irq
= platform_get_irq(pdev
, 0);
443 clk_disable(config
->clk
);
444 clk_put(config
->clk
);
445 iounmap(config
->ioaddr
);
447 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
449 release_mem_region(res
->start
, resource_size(res
));
450 platform_set_drvdata(pdev
, NULL
);
451 dev_set_drvdata(&rtc
->dev
, NULL
);
452 rtc_device_unregister(rtc
);
459 static int spear_rtc_suspend(struct platform_device
*pdev
, pm_message_t state
)
461 struct rtc_device
*rtc
= platform_get_drvdata(pdev
);
462 struct spear_rtc_config
*config
= dev_get_drvdata(&rtc
->dev
);
465 irq
= platform_get_irq(pdev
, 0);
466 if (device_may_wakeup(&pdev
->dev
))
467 enable_irq_wake(irq
);
469 spear_rtc_disable_interrupt(config
);
470 clk_disable(config
->clk
);
476 static int spear_rtc_resume(struct platform_device
*pdev
)
478 struct rtc_device
*rtc
= platform_get_drvdata(pdev
);
479 struct spear_rtc_config
*config
= dev_get_drvdata(&rtc
->dev
);
482 irq
= platform_get_irq(pdev
, 0);
484 if (device_may_wakeup(&pdev
->dev
))
485 disable_irq_wake(irq
);
487 clk_enable(config
->clk
);
488 spear_rtc_enable_interrupt(config
);
495 #define spear_rtc_suspend NULL
496 #define spear_rtc_resume NULL
499 static void spear_rtc_shutdown(struct platform_device
*pdev
)
501 struct rtc_device
*rtc
= platform_get_drvdata(pdev
);
502 struct spear_rtc_config
*config
= dev_get_drvdata(&rtc
->dev
);
504 spear_rtc_disable_interrupt(config
);
505 clk_disable(config
->clk
);
508 static struct platform_driver spear_rtc_driver
= {
509 .probe
= spear_rtc_probe
,
510 .remove
= __devexit_p(spear_rtc_remove
),
511 .suspend
= spear_rtc_suspend
,
512 .resume
= spear_rtc_resume
,
513 .shutdown
= spear_rtc_shutdown
,
519 module_platform_driver(spear_rtc_driver
);
521 MODULE_ALIAS("platform:rtc-spear");
522 MODULE_AUTHOR("Rajeev Kumar <rajeev-dlh.kumar@st.com>");
523 MODULE_DESCRIPTION("ST SPEAr Realtime Clock Driver (RTC)");
524 MODULE_LICENSE("GPL");