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 {
83 unsigned int irq_wake;
86 static inline void spear_rtc_clear_interrupt(struct spear_rtc_config *config)
91 spin_lock_irqsave(&config->lock, flags);
92 val = readl(config->ioaddr + STATUS_REG);
94 writel(val, config->ioaddr + STATUS_REG);
95 spin_unlock_irqrestore(&config->lock, flags);
98 static inline void spear_rtc_enable_interrupt(struct spear_rtc_config *config)
102 val = readl(config->ioaddr + CTRL_REG);
103 if (!(val & INT_ENABLE)) {
104 spear_rtc_clear_interrupt(config);
106 writel(val, config->ioaddr + CTRL_REG);
110 static inline void spear_rtc_disable_interrupt(struct spear_rtc_config *config)
114 val = readl(config->ioaddr + CTRL_REG);
115 if (val & INT_ENABLE) {
117 writel(val, config->ioaddr + CTRL_REG);
121 static inline int is_write_complete(struct spear_rtc_config *config)
126 spin_lock_irqsave(&config->lock, flags);
127 if ((readl(config->ioaddr + STATUS_REG)) & STATUS_FAIL)
129 spin_unlock_irqrestore(&config->lock, flags);
134 static void rtc_wait_not_busy(struct spear_rtc_config *config)
136 int status, count = 0;
139 /* Assuming BUSY may stay active for 80 msec) */
140 for (count = 0; count < 80; count++) {
141 spin_lock_irqsave(&config->lock, flags);
142 status = readl(config->ioaddr + STATUS_REG);
143 spin_unlock_irqrestore(&config->lock, flags);
144 if ((status & STATUS_BUSY) == 0)
146 /* check status busy, after each msec */
151 static irqreturn_t spear_rtc_irq(int irq, void *dev_id)
153 struct rtc_device *rtc = (struct rtc_device *)dev_id;
154 struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);
155 unsigned long flags, events = 0;
156 unsigned int irq_data;
158 spin_lock_irqsave(&config->lock, flags);
159 irq_data = readl(config->ioaddr + STATUS_REG);
160 spin_unlock_irqrestore(&config->lock, flags);
162 if ((irq_data & RTC_INT_MASK)) {
163 spear_rtc_clear_interrupt(config);
164 events = RTC_IRQF | RTC_AF;
165 rtc_update_irq(rtc, 1, events);
172 static int tm2bcd(struct rtc_time *tm)
174 if (rtc_valid_tm(tm) != 0)
176 tm->tm_sec = bin2bcd(tm->tm_sec);
177 tm->tm_min = bin2bcd(tm->tm_min);
178 tm->tm_hour = bin2bcd(tm->tm_hour);
179 tm->tm_mday = bin2bcd(tm->tm_mday);
180 tm->tm_mon = bin2bcd(tm->tm_mon + 1);
181 tm->tm_year = bin2bcd(tm->tm_year);
186 static void bcd2tm(struct rtc_time *tm)
188 tm->tm_sec = bcd2bin(tm->tm_sec);
189 tm->tm_min = bcd2bin(tm->tm_min);
190 tm->tm_hour = bcd2bin(tm->tm_hour);
191 tm->tm_mday = bcd2bin(tm->tm_mday);
192 tm->tm_mon = bcd2bin(tm->tm_mon) - 1;
194 tm->tm_year = bcd2bin(tm->tm_year);
198 * spear_rtc_read_time - set the time
199 * @dev: rtc device in use
200 * @tm: holds date and time
202 * This function read time and date. On success it will return 0
203 * otherwise -ve error is returned.
205 static int spear_rtc_read_time(struct device *dev, struct rtc_time *tm)
207 struct platform_device *pdev = to_platform_device(dev);
208 struct rtc_device *rtc = platform_get_drvdata(pdev);
209 struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);
210 unsigned int time, date;
212 /* we don't report wday/yday/isdst ... */
213 rtc_wait_not_busy(config);
215 time = readl(config->ioaddr + TIME_REG);
216 date = readl(config->ioaddr + DATE_REG);
217 tm->tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK;
218 tm->tm_min = (time >> MINUTE_SHIFT) & MIN_MASK;
219 tm->tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK;
220 tm->tm_mday = (date >> MDAY_SHIFT) & DAY_MASK;
221 tm->tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK;
222 tm->tm_year = (date >> YEAR_SHIFT) & YEAR_MASK;
229 * spear_rtc_set_time - set the time
230 * @dev: rtc device in use
231 * @tm: holds date and time
233 * This function set time and date. On success it will return 0
234 * otherwise -ve error is returned.
236 static int spear_rtc_set_time(struct device *dev, struct rtc_time *tm)
238 struct platform_device *pdev = to_platform_device(dev);
239 struct rtc_device *rtc = platform_get_drvdata(pdev);
240 struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);
241 unsigned int time, date, err = 0;
246 rtc_wait_not_busy(config);
247 time = (tm->tm_sec << SECOND_SHIFT) | (tm->tm_min << MINUTE_SHIFT) |
248 (tm->tm_hour << HOUR_SHIFT);
249 date = (tm->tm_mday << MDAY_SHIFT) | (tm->tm_mon << MONTH_SHIFT) |
250 (tm->tm_year << YEAR_SHIFT);
251 writel(time, config->ioaddr + TIME_REG);
252 writel(date, config->ioaddr + DATE_REG);
253 err = is_write_complete(config);
261 * spear_rtc_read_alarm - read the alarm time
262 * @dev: rtc device in use
263 * @alm: holds alarm date and time
265 * This function read alarm time and date. On success it will return 0
266 * otherwise -ve error is returned.
268 static int spear_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
270 struct platform_device *pdev = to_platform_device(dev);
271 struct rtc_device *rtc = platform_get_drvdata(pdev);
272 struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);
273 unsigned int time, date;
275 rtc_wait_not_busy(config);
277 time = readl(config->ioaddr + ALARM_TIME_REG);
278 date = readl(config->ioaddr + ALARM_DATE_REG);
279 alm->time.tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK;
280 alm->time.tm_min = (time >> MINUTE_SHIFT) & MIN_MASK;
281 alm->time.tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK;
282 alm->time.tm_mday = (date >> MDAY_SHIFT) & DAY_MASK;
283 alm->time.tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK;
284 alm->time.tm_year = (date >> YEAR_SHIFT) & YEAR_MASK;
287 alm->enabled = readl(config->ioaddr + CTRL_REG) & INT_ENABLE;
293 * spear_rtc_set_alarm - set the alarm time
294 * @dev: rtc device in use
295 * @alm: holds alarm date and time
297 * This function set alarm time and date. On success it will return 0
298 * otherwise -ve error is returned.
300 static int spear_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
302 struct platform_device *pdev = to_platform_device(dev);
303 struct rtc_device *rtc = platform_get_drvdata(pdev);
304 struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);
305 unsigned int time, date, err = 0;
307 if (tm2bcd(&alm->time) < 0)
310 rtc_wait_not_busy(config);
312 time = (alm->time.tm_sec << SECOND_SHIFT) | (alm->time.tm_min <<
313 MINUTE_SHIFT) | (alm->time.tm_hour << HOUR_SHIFT);
314 date = (alm->time.tm_mday << MDAY_SHIFT) | (alm->time.tm_mon <<
315 MONTH_SHIFT) | (alm->time.tm_year << YEAR_SHIFT);
317 writel(time, config->ioaddr + ALARM_TIME_REG);
318 writel(date, config->ioaddr + ALARM_DATE_REG);
319 err = is_write_complete(config);
324 spear_rtc_enable_interrupt(config);
326 spear_rtc_disable_interrupt(config);
331 static int spear_alarm_irq_enable(struct device *dev, unsigned int enabled)
333 struct platform_device *pdev = to_platform_device(dev);
334 struct rtc_device *rtc = platform_get_drvdata(pdev);
335 struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);
338 spear_rtc_clear_interrupt(config);
343 spear_rtc_disable_interrupt(config);
347 spear_rtc_enable_interrupt(config);
357 static struct rtc_class_ops spear_rtc_ops = {
358 .read_time = spear_rtc_read_time,
359 .set_time = spear_rtc_set_time,
360 .read_alarm = spear_rtc_read_alarm,
361 .set_alarm = spear_rtc_set_alarm,
362 .alarm_irq_enable = spear_alarm_irq_enable,
365 static int __devinit spear_rtc_probe(struct platform_device *pdev)
367 struct resource *res;
368 struct rtc_device *rtc;
369 struct spear_rtc_config *config;
370 unsigned int status = 0;
373 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
375 dev_err(&pdev->dev, "no resource defined\n");
378 if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
379 dev_err(&pdev->dev, "rtc region already claimed\n");
383 config = kzalloc(sizeof(*config), GFP_KERNEL);
385 dev_err(&pdev->dev, "out of memory\n");
387 goto err_release_region;
390 config->clk = clk_get(&pdev->dev, NULL);
391 if (IS_ERR(config->clk)) {
392 status = PTR_ERR(config->clk);
396 status = clk_enable(config->clk);
400 config->ioaddr = ioremap(res->start, resource_size(res));
401 if (!config->ioaddr) {
402 dev_err(&pdev->dev, "ioremap fail\n");
404 goto err_disable_clock;
407 spin_lock_init(&config->lock);
409 rtc = rtc_device_register(pdev->name, &pdev->dev, &spear_rtc_ops,
412 dev_err(&pdev->dev, "can't register RTC device, err %ld\n",
414 status = PTR_ERR(rtc);
418 platform_set_drvdata(pdev, rtc);
419 dev_set_drvdata(&rtc->dev, config);
422 irq = platform_get_irq(pdev, 0);
424 dev_err(&pdev->dev, "no update irq?\n");
426 goto err_clear_platdata;
429 status = request_irq(irq, spear_rtc_irq, 0, pdev->name, rtc);
431 dev_err(&pdev->dev, "Alarm interrupt IRQ%d already \
433 goto err_clear_platdata;
436 if (!device_can_wakeup(&pdev->dev))
437 device_init_wakeup(&pdev->dev, 1);
442 platform_set_drvdata(pdev, NULL);
443 dev_set_drvdata(&rtc->dev, NULL);
444 rtc_device_unregister(rtc);
446 iounmap(config->ioaddr);
448 clk_disable(config->clk);
450 clk_put(config->clk);
454 release_mem_region(res->start, resource_size(res));
459 static int __devexit spear_rtc_remove(struct platform_device *pdev)
461 struct rtc_device *rtc = platform_get_drvdata(pdev);
462 struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);
464 struct resource *res;
466 /* leave rtc running, but disable irqs */
467 spear_rtc_disable_interrupt(config);
468 device_init_wakeup(&pdev->dev, 0);
469 irq = platform_get_irq(pdev, 0);
472 clk_disable(config->clk);
473 clk_put(config->clk);
474 iounmap(config->ioaddr);
476 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
478 release_mem_region(res->start, resource_size(res));
479 platform_set_drvdata(pdev, NULL);
480 dev_set_drvdata(&rtc->dev, NULL);
481 rtc_device_unregister(rtc);
488 static int spear_rtc_suspend(struct platform_device *pdev, pm_message_t state)
490 struct rtc_device *rtc = platform_get_drvdata(pdev);
491 struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);
494 irq = platform_get_irq(pdev, 0);
495 if (device_may_wakeup(&pdev->dev)) {
496 if (!enable_irq_wake(irq))
497 config->irq_wake = 1;
499 spear_rtc_disable_interrupt(config);
500 clk_disable(config->clk);
506 static int spear_rtc_resume(struct platform_device *pdev)
508 struct rtc_device *rtc = platform_get_drvdata(pdev);
509 struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);
512 irq = platform_get_irq(pdev, 0);
514 if (device_may_wakeup(&pdev->dev)) {
515 if (config->irq_wake) {
516 disable_irq_wake(irq);
517 config->irq_wake = 0;
520 clk_enable(config->clk);
521 spear_rtc_enable_interrupt(config);
528 #define spear_rtc_suspend NULL
529 #define spear_rtc_resume NULL
532 static void spear_rtc_shutdown(struct platform_device *pdev)
534 struct rtc_device *rtc = platform_get_drvdata(pdev);
535 struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);
537 spear_rtc_disable_interrupt(config);
538 clk_disable(config->clk);
541 static struct platform_driver spear_rtc_driver = {
542 .probe = spear_rtc_probe,
543 .remove = __devexit_p(spear_rtc_remove),
544 .suspend = spear_rtc_suspend,
545 .resume = spear_rtc_resume,
546 .shutdown = spear_rtc_shutdown,
552 module_platform_driver(spear_rtc_driver);
554 MODULE_ALIAS("platform:rtc-spear");
555 MODULE_AUTHOR("Rajeev Kumar <rajeev-dlh.kumar@st.com>");
556 MODULE_DESCRIPTION("ST SPEAr Realtime Clock Driver (RTC)");
557 MODULE_LICENSE("GPL");