fix a kmap leak in virtio_console
[linux/fpc-iii.git] / drivers / rtc / rtc-at91rm9200.c
blob3281c90691c3e143fe14142c9234e3f0a60650e6
1 /*
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>
31 #include <linux/io.h>
32 #include <linux/of.h>
33 #include <linux/of_device.h>
34 #include <linux/uaccess.h>
36 #include "rtc-at91rm9200.h"
38 #define at91_rtc_read(field) \
39 __raw_readl(at91_rtc_regs + field)
40 #define at91_rtc_write(field, val) \
41 __raw_writel((val), at91_rtc_regs + field)
43 #define AT91_RTC_EPOCH 1900UL /* just like arch/arm/common/rtctime.c */
45 struct at91_rtc_config {
46 bool use_shadow_imr;
49 static const struct at91_rtc_config *at91_rtc_config;
50 static DECLARE_COMPLETION(at91_rtc_updated);
51 static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
52 static void __iomem *at91_rtc_regs;
53 static int irq;
54 static DEFINE_SPINLOCK(at91_rtc_lock);
55 static u32 at91_rtc_shadow_imr;
57 static void at91_rtc_write_ier(u32 mask)
59 unsigned long flags;
61 spin_lock_irqsave(&at91_rtc_lock, flags);
62 at91_rtc_shadow_imr |= mask;
63 at91_rtc_write(AT91_RTC_IER, mask);
64 spin_unlock_irqrestore(&at91_rtc_lock, flags);
67 static void at91_rtc_write_idr(u32 mask)
69 unsigned long flags;
71 spin_lock_irqsave(&at91_rtc_lock, flags);
72 at91_rtc_write(AT91_RTC_IDR, mask);
74 * Register read back (of any RTC-register) needed to make sure
75 * IDR-register write has reached the peripheral before updating
76 * shadow mask.
78 * Note that there is still a possibility that the mask is updated
79 * before interrupts have actually been disabled in hardware. The only
80 * way to be certain would be to poll the IMR-register, which is is
81 * the very register we are trying to emulate. The register read back
82 * is a reasonable heuristic.
84 at91_rtc_read(AT91_RTC_SR);
85 at91_rtc_shadow_imr &= ~mask;
86 spin_unlock_irqrestore(&at91_rtc_lock, flags);
89 static u32 at91_rtc_read_imr(void)
91 unsigned long flags;
92 u32 mask;
94 if (at91_rtc_config->use_shadow_imr) {
95 spin_lock_irqsave(&at91_rtc_lock, flags);
96 mask = at91_rtc_shadow_imr;
97 spin_unlock_irqrestore(&at91_rtc_lock, flags);
98 } else {
99 mask = at91_rtc_read(AT91_RTC_IMR);
102 return mask;
106 * Decode time/date into rtc_time structure
108 static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
109 struct rtc_time *tm)
111 unsigned int time, date;
113 /* must read twice in case it changes */
114 do {
115 time = at91_rtc_read(timereg);
116 date = at91_rtc_read(calreg);
117 } while ((time != at91_rtc_read(timereg)) ||
118 (date != at91_rtc_read(calreg)));
120 tm->tm_sec = bcd2bin((time & AT91_RTC_SEC) >> 0);
121 tm->tm_min = bcd2bin((time & AT91_RTC_MIN) >> 8);
122 tm->tm_hour = bcd2bin((time & AT91_RTC_HOUR) >> 16);
125 * The Calendar Alarm register does not have a field for
126 * the year - so these will return an invalid value. When an
127 * alarm is set, at91_alarm_year will store the current year.
129 tm->tm_year = bcd2bin(date & AT91_RTC_CENT) * 100; /* century */
130 tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8); /* year */
132 tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */
133 tm->tm_mon = bcd2bin((date & AT91_RTC_MONTH) >> 16) - 1;
134 tm->tm_mday = bcd2bin((date & AT91_RTC_DATE) >> 24);
138 * Read current time and date in RTC
140 static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
142 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
143 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
144 tm->tm_year = tm->tm_year - 1900;
146 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
147 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
148 tm->tm_hour, tm->tm_min, tm->tm_sec);
150 return 0;
154 * Set current time and date in RTC
156 static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
158 unsigned long cr;
160 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
161 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
162 tm->tm_hour, tm->tm_min, tm->tm_sec);
164 /* Stop Time/Calendar from counting */
165 cr = at91_rtc_read(AT91_RTC_CR);
166 at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
168 at91_rtc_write_ier(AT91_RTC_ACKUPD);
169 wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
170 at91_rtc_write_idr(AT91_RTC_ACKUPD);
172 at91_rtc_write(AT91_RTC_TIMR,
173 bin2bcd(tm->tm_sec) << 0
174 | bin2bcd(tm->tm_min) << 8
175 | bin2bcd(tm->tm_hour) << 16);
177 at91_rtc_write(AT91_RTC_CALR,
178 bin2bcd((tm->tm_year + 1900) / 100) /* century */
179 | bin2bcd(tm->tm_year % 100) << 8 /* year */
180 | bin2bcd(tm->tm_mon + 1) << 16 /* tm_mon starts at zero */
181 | bin2bcd(tm->tm_wday + 1) << 21 /* day of the week [0-6], Sunday=0 */
182 | bin2bcd(tm->tm_mday) << 24);
184 /* Restart Time/Calendar */
185 cr = at91_rtc_read(AT91_RTC_CR);
186 at91_rtc_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
188 return 0;
192 * Read alarm time and date in RTC
194 static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
196 struct rtc_time *tm = &alrm->time;
198 at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
199 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
200 tm->tm_year = at91_alarm_year - 1900;
202 alrm->enabled = (at91_rtc_read_imr() & AT91_RTC_ALARM)
203 ? 1 : 0;
205 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
206 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
207 tm->tm_hour, tm->tm_min, tm->tm_sec);
209 return 0;
213 * Set alarm time and date in RTC
215 static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
217 struct rtc_time tm;
219 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm);
221 at91_alarm_year = tm.tm_year;
223 tm.tm_mon = alrm->time.tm_mon;
224 tm.tm_mday = alrm->time.tm_mday;
225 tm.tm_hour = alrm->time.tm_hour;
226 tm.tm_min = alrm->time.tm_min;
227 tm.tm_sec = alrm->time.tm_sec;
229 at91_rtc_write_idr(AT91_RTC_ALARM);
230 at91_rtc_write(AT91_RTC_TIMALR,
231 bin2bcd(tm.tm_sec) << 0
232 | bin2bcd(tm.tm_min) << 8
233 | bin2bcd(tm.tm_hour) << 16
234 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
235 at91_rtc_write(AT91_RTC_CALALR,
236 bin2bcd(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */
237 | bin2bcd(tm.tm_mday) << 24
238 | AT91_RTC_DATEEN | AT91_RTC_MTHEN);
240 if (alrm->enabled) {
241 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
242 at91_rtc_write_ier(AT91_RTC_ALARM);
245 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
246 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
247 tm.tm_min, tm.tm_sec);
249 return 0;
252 static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
254 dev_dbg(dev, "%s(): cmd=%08x\n", __func__, enabled);
256 if (enabled) {
257 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
258 at91_rtc_write_ier(AT91_RTC_ALARM);
259 } else
260 at91_rtc_write_idr(AT91_RTC_ALARM);
262 return 0;
265 * Provide additional RTC information in /proc/driver/rtc
267 static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
269 unsigned long imr = at91_rtc_read_imr();
271 seq_printf(seq, "update_IRQ\t: %s\n",
272 (imr & AT91_RTC_ACKUPD) ? "yes" : "no");
273 seq_printf(seq, "periodic_IRQ\t: %s\n",
274 (imr & AT91_RTC_SECEV) ? "yes" : "no");
276 return 0;
280 * IRQ handler for the RTC
282 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
284 struct platform_device *pdev = dev_id;
285 struct rtc_device *rtc = platform_get_drvdata(pdev);
286 unsigned int rtsr;
287 unsigned long events = 0;
289 rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read_imr();
290 if (rtsr) { /* this interrupt is shared! Is it ours? */
291 if (rtsr & AT91_RTC_ALARM)
292 events |= (RTC_AF | RTC_IRQF);
293 if (rtsr & AT91_RTC_SECEV)
294 events |= (RTC_UF | RTC_IRQF);
295 if (rtsr & AT91_RTC_ACKUPD)
296 complete(&at91_rtc_updated);
298 at91_rtc_write(AT91_RTC_SCCR, rtsr); /* clear status reg */
300 rtc_update_irq(rtc, 1, events);
302 dev_dbg(&pdev->dev, "%s(): num=%ld, events=0x%02lx\n", __func__,
303 events >> 8, events & 0x000000FF);
305 return IRQ_HANDLED;
307 return IRQ_NONE; /* not handled */
310 static const struct at91_rtc_config at91rm9200_config = {
313 static const struct at91_rtc_config at91sam9x5_config = {
314 .use_shadow_imr = true,
317 #ifdef CONFIG_OF
318 static const struct of_device_id at91_rtc_dt_ids[] = {
320 .compatible = "atmel,at91rm9200-rtc",
321 .data = &at91rm9200_config,
322 }, {
323 .compatible = "atmel,at91sam9x5-rtc",
324 .data = &at91sam9x5_config,
325 }, {
326 /* sentinel */
329 MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
330 #endif
332 static const struct at91_rtc_config *
333 at91_rtc_get_config(struct platform_device *pdev)
335 const struct of_device_id *match;
337 if (pdev->dev.of_node) {
338 match = of_match_node(at91_rtc_dt_ids, pdev->dev.of_node);
339 if (!match)
340 return NULL;
341 return (const struct at91_rtc_config *)match->data;
344 return &at91rm9200_config;
347 static const struct rtc_class_ops at91_rtc_ops = {
348 .read_time = at91_rtc_readtime,
349 .set_time = at91_rtc_settime,
350 .read_alarm = at91_rtc_readalarm,
351 .set_alarm = at91_rtc_setalarm,
352 .proc = at91_rtc_proc,
353 .alarm_irq_enable = at91_rtc_alarm_irq_enable,
357 * Initialize and install RTC driver
359 static int __init at91_rtc_probe(struct platform_device *pdev)
361 struct rtc_device *rtc;
362 struct resource *regs;
363 int ret = 0;
365 at91_rtc_config = at91_rtc_get_config(pdev);
366 if (!at91_rtc_config)
367 return -ENODEV;
369 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
370 if (!regs) {
371 dev_err(&pdev->dev, "no mmio resource defined\n");
372 return -ENXIO;
375 irq = platform_get_irq(pdev, 0);
376 if (irq < 0) {
377 dev_err(&pdev->dev, "no irq resource defined\n");
378 return -ENXIO;
381 at91_rtc_regs = devm_ioremap(&pdev->dev, regs->start,
382 resource_size(regs));
383 if (!at91_rtc_regs) {
384 dev_err(&pdev->dev, "failed to map registers, aborting.\n");
385 return -ENOMEM;
388 at91_rtc_write(AT91_RTC_CR, 0);
389 at91_rtc_write(AT91_RTC_MR, 0); /* 24 hour mode */
391 /* Disable all interrupts */
392 at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM |
393 AT91_RTC_SECEV | AT91_RTC_TIMEV |
394 AT91_RTC_CALEV);
396 ret = devm_request_irq(&pdev->dev, irq, at91_rtc_interrupt,
397 IRQF_SHARED,
398 "at91_rtc", pdev);
399 if (ret) {
400 dev_err(&pdev->dev, "IRQ %d already in use.\n", irq);
401 return ret;
404 /* cpu init code should really have flagged this device as
405 * being wake-capable; if it didn't, do that here.
407 if (!device_can_wakeup(&pdev->dev))
408 device_init_wakeup(&pdev->dev, 1);
410 rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
411 &at91_rtc_ops, THIS_MODULE);
412 if (IS_ERR(rtc))
413 return PTR_ERR(rtc);
414 platform_set_drvdata(pdev, rtc);
416 dev_info(&pdev->dev, "AT91 Real Time Clock driver.\n");
417 return 0;
421 * Disable and remove the RTC driver
423 static int __exit at91_rtc_remove(struct platform_device *pdev)
425 /* Disable all interrupts */
426 at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM |
427 AT91_RTC_SECEV | AT91_RTC_TIMEV |
428 AT91_RTC_CALEV);
430 return 0;
433 static void at91_rtc_shutdown(struct platform_device *pdev)
435 /* Disable all interrupts */
436 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
437 AT91_RTC_SECEV | AT91_RTC_TIMEV |
438 AT91_RTC_CALEV);
441 #ifdef CONFIG_PM_SLEEP
443 /* AT91RM9200 RTC Power management control */
445 static u32 at91_rtc_imr;
447 static int at91_rtc_suspend(struct device *dev)
449 /* this IRQ is shared with DBGU and other hardware which isn't
450 * necessarily doing PM like we are...
452 at91_rtc_imr = at91_rtc_read_imr()
453 & (AT91_RTC_ALARM|AT91_RTC_SECEV);
454 if (at91_rtc_imr) {
455 if (device_may_wakeup(dev))
456 enable_irq_wake(irq);
457 else
458 at91_rtc_write_idr(at91_rtc_imr);
460 return 0;
463 static int at91_rtc_resume(struct device *dev)
465 if (at91_rtc_imr) {
466 if (device_may_wakeup(dev))
467 disable_irq_wake(irq);
468 else
469 at91_rtc_write_ier(at91_rtc_imr);
471 return 0;
473 #endif
475 static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume);
477 static struct platform_driver at91_rtc_driver = {
478 .remove = __exit_p(at91_rtc_remove),
479 .shutdown = at91_rtc_shutdown,
480 .driver = {
481 .name = "at91_rtc",
482 .owner = THIS_MODULE,
483 .pm = &at91_rtc_pm_ops,
484 .of_match_table = of_match_ptr(at91_rtc_dt_ids),
488 module_platform_driver_probe(at91_rtc_driver, at91_rtc_probe);
490 MODULE_AUTHOR("Rick Bronson");
491 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
492 MODULE_LICENSE("GPL");
493 MODULE_ALIAS("platform:at91_rtc");