2 * SuperH On-Chip RTC Support
4 * Copyright (C) 2006 - 2009 Paul Mundt
5 * Copyright (C) 2006 Jamie Lenehan
6 * Copyright (C) 2008 Angelo Castello
8 * Based on the old arch/sh/kernel/cpu/rtc.c by:
11 * Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
13 * This file is subject to the terms and conditions of the GNU General Public
14 * License. See the file "COPYING" in the main directory of this archive
17 #include <linux/module.h>
18 #include <linux/mod_devicetable.h>
19 #include <linux/kernel.h>
20 #include <linux/bcd.h>
21 #include <linux/rtc.h>
22 #include <linux/init.h>
23 #include <linux/platform_device.h>
24 #include <linux/seq_file.h>
25 #include <linux/interrupt.h>
26 #include <linux/spinlock.h>
28 #include <linux/log2.h>
29 #include <linux/clk.h>
30 #include <linux/slab.h>
34 /* Default values for RZ/A RTC */
35 #define rtc_reg_size sizeof(u16)
36 #define RTC_BIT_INVERTED 0 /* no chip bugs */
37 #define RTC_CAP_4_DIGIT_YEAR (1 << 0)
38 #define RTC_DEF_CAPABILITIES RTC_CAP_4_DIGIT_YEAR
41 #define DRV_NAME "sh-rtc"
43 #define RTC_REG(r) ((r) * rtc_reg_size)
45 #define R64CNT RTC_REG(0)
47 #define RSECCNT RTC_REG(1) /* RTC sec */
48 #define RMINCNT RTC_REG(2) /* RTC min */
49 #define RHRCNT RTC_REG(3) /* RTC hour */
50 #define RWKCNT RTC_REG(4) /* RTC week */
51 #define RDAYCNT RTC_REG(5) /* RTC day */
52 #define RMONCNT RTC_REG(6) /* RTC month */
53 #define RYRCNT RTC_REG(7) /* RTC year */
54 #define RSECAR RTC_REG(8) /* ALARM sec */
55 #define RMINAR RTC_REG(9) /* ALARM min */
56 #define RHRAR RTC_REG(10) /* ALARM hour */
57 #define RWKAR RTC_REG(11) /* ALARM week */
58 #define RDAYAR RTC_REG(12) /* ALARM day */
59 #define RMONAR RTC_REG(13) /* ALARM month */
60 #define RCR1 RTC_REG(14) /* Control */
61 #define RCR2 RTC_REG(15) /* Control */
64 * Note on RYRAR and RCR3: Up until this point most of the register
65 * definitions are consistent across all of the available parts. However,
66 * the placement of the optional RYRAR and RCR3 (the RYRAR control
67 * register used to control RYRCNT/RYRAR compare) varies considerably
68 * across various parts, occasionally being mapped in to a completely
69 * unrelated address space. For proper RYRAR support a separate resource
70 * would have to be handed off, but as this is purely optional in
71 * practice, we simply opt not to support it, thereby keeping the code
72 * quite a bit more simplified.
75 /* ALARM Bits - or with BCD encoded value */
76 #define AR_ENB 0x80 /* Enable for alarm cmp */
79 #define PF_HP 0x100 /* Enable Half Period to support 8,32,128Hz */
80 #define PF_COUNT 0x200 /* Half periodic counter */
81 #define PF_OXS 0x400 /* Periodic One x Second */
82 #define PF_KOU 0x800 /* Kernel or User periodic request 1=kernel */
86 #define RCR1_CF 0x80 /* Carry Flag */
87 #define RCR1_CIE 0x10 /* Carry Interrupt Enable */
88 #define RCR1_AIE 0x08 /* Alarm Interrupt Enable */
89 #define RCR1_AF 0x01 /* Alarm Flag */
92 #define RCR2_PEF 0x80 /* PEriodic interrupt Flag */
93 #define RCR2_PESMASK 0x70 /* Periodic interrupt Set */
94 #define RCR2_RTCEN 0x08 /* ENable RTC */
95 #define RCR2_ADJ 0x04 /* ADJustment (30-second) */
96 #define RCR2_RESET 0x02 /* Reset bit */
97 #define RCR2_START 0x01 /* Start bit */
100 void __iomem *regbase;
101 unsigned long regsize;
102 struct resource *res;
107 struct rtc_device *rtc_dev;
109 unsigned long capabilities; /* See asm/rtc.h for cap bits */
110 unsigned short periodic_freq;
113 static int __sh_rtc_interrupt(struct sh_rtc *rtc)
115 unsigned int tmp, pending;
117 tmp = readb(rtc->regbase + RCR1);
118 pending = tmp & RCR1_CF;
120 writeb(tmp, rtc->regbase + RCR1);
122 /* Users have requested One x Second IRQ */
123 if (pending && rtc->periodic_freq & PF_OXS)
124 rtc_update_irq(rtc->rtc_dev, 1, RTC_UF | RTC_IRQF);
129 static int __sh_rtc_alarm(struct sh_rtc *rtc)
131 unsigned int tmp, pending;
133 tmp = readb(rtc->regbase + RCR1);
134 pending = tmp & RCR1_AF;
135 tmp &= ~(RCR1_AF | RCR1_AIE);
136 writeb(tmp, rtc->regbase + RCR1);
139 rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);
144 static int __sh_rtc_periodic(struct sh_rtc *rtc)
146 unsigned int tmp, pending;
148 tmp = readb(rtc->regbase + RCR2);
149 pending = tmp & RCR2_PEF;
151 writeb(tmp, rtc->regbase + RCR2);
156 /* Half period enabled than one skipped and the next notified */
157 if ((rtc->periodic_freq & PF_HP) && (rtc->periodic_freq & PF_COUNT))
158 rtc->periodic_freq &= ~PF_COUNT;
160 if (rtc->periodic_freq & PF_HP)
161 rtc->periodic_freq |= PF_COUNT;
162 rtc_update_irq(rtc->rtc_dev, 1, RTC_PF | RTC_IRQF);
168 static irqreturn_t sh_rtc_interrupt(int irq, void *dev_id)
170 struct sh_rtc *rtc = dev_id;
173 spin_lock(&rtc->lock);
174 ret = __sh_rtc_interrupt(rtc);
175 spin_unlock(&rtc->lock);
177 return IRQ_RETVAL(ret);
180 static irqreturn_t sh_rtc_alarm(int irq, void *dev_id)
182 struct sh_rtc *rtc = dev_id;
185 spin_lock(&rtc->lock);
186 ret = __sh_rtc_alarm(rtc);
187 spin_unlock(&rtc->lock);
189 return IRQ_RETVAL(ret);
192 static irqreturn_t sh_rtc_periodic(int irq, void *dev_id)
194 struct sh_rtc *rtc = dev_id;
197 spin_lock(&rtc->lock);
198 ret = __sh_rtc_periodic(rtc);
199 spin_unlock(&rtc->lock);
201 return IRQ_RETVAL(ret);
204 static irqreturn_t sh_rtc_shared(int irq, void *dev_id)
206 struct sh_rtc *rtc = dev_id;
209 spin_lock(&rtc->lock);
210 ret = __sh_rtc_interrupt(rtc);
211 ret |= __sh_rtc_alarm(rtc);
212 ret |= __sh_rtc_periodic(rtc);
213 spin_unlock(&rtc->lock);
215 return IRQ_RETVAL(ret);
218 static inline void sh_rtc_setaie(struct device *dev, unsigned int enable)
220 struct sh_rtc *rtc = dev_get_drvdata(dev);
223 spin_lock_irq(&rtc->lock);
225 tmp = readb(rtc->regbase + RCR1);
232 writeb(tmp, rtc->regbase + RCR1);
234 spin_unlock_irq(&rtc->lock);
237 static int sh_rtc_proc(struct device *dev, struct seq_file *seq)
239 struct sh_rtc *rtc = dev_get_drvdata(dev);
242 tmp = readb(rtc->regbase + RCR1);
243 seq_printf(seq, "carry_IRQ\t: %s\n", (tmp & RCR1_CIE) ? "yes" : "no");
245 tmp = readb(rtc->regbase + RCR2);
246 seq_printf(seq, "periodic_IRQ\t: %s\n",
247 (tmp & RCR2_PESMASK) ? "yes" : "no");
252 static inline void sh_rtc_setcie(struct device *dev, unsigned int enable)
254 struct sh_rtc *rtc = dev_get_drvdata(dev);
257 spin_lock_irq(&rtc->lock);
259 tmp = readb(rtc->regbase + RCR1);
266 writeb(tmp, rtc->regbase + RCR1);
268 spin_unlock_irq(&rtc->lock);
271 static int sh_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
273 sh_rtc_setaie(dev, enabled);
277 static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
279 struct sh_rtc *rtc = dev_get_drvdata(dev);
280 unsigned int sec128, sec2, yr, yr100, cf_bit;
285 spin_lock_irq(&rtc->lock);
287 tmp = readb(rtc->regbase + RCR1);
288 tmp &= ~RCR1_CF; /* Clear CF-bit */
290 writeb(tmp, rtc->regbase + RCR1);
292 sec128 = readb(rtc->regbase + R64CNT);
294 tm->tm_sec = bcd2bin(readb(rtc->regbase + RSECCNT));
295 tm->tm_min = bcd2bin(readb(rtc->regbase + RMINCNT));
296 tm->tm_hour = bcd2bin(readb(rtc->regbase + RHRCNT));
297 tm->tm_wday = bcd2bin(readb(rtc->regbase + RWKCNT));
298 tm->tm_mday = bcd2bin(readb(rtc->regbase + RDAYCNT));
299 tm->tm_mon = bcd2bin(readb(rtc->regbase + RMONCNT)) - 1;
301 if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
302 yr = readw(rtc->regbase + RYRCNT);
303 yr100 = bcd2bin(yr >> 8);
306 yr = readb(rtc->regbase + RYRCNT);
307 yr100 = bcd2bin((yr == 0x99) ? 0x19 : 0x20);
310 tm->tm_year = (yr100 * 100 + bcd2bin(yr)) - 1900;
312 sec2 = readb(rtc->regbase + R64CNT);
313 cf_bit = readb(rtc->regbase + RCR1) & RCR1_CF;
315 spin_unlock_irq(&rtc->lock);
316 } while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0);
318 #if RTC_BIT_INVERTED != 0
319 if ((sec128 & RTC_BIT_INVERTED))
323 /* only keep the carry interrupt enabled if UIE is on */
324 if (!(rtc->periodic_freq & PF_OXS))
325 sh_rtc_setcie(dev, 0);
327 dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
328 "mday=%d, mon=%d, year=%d, wday=%d\n",
330 tm->tm_sec, tm->tm_min, tm->tm_hour,
331 tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
336 static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm)
338 struct sh_rtc *rtc = dev_get_drvdata(dev);
342 spin_lock_irq(&rtc->lock);
344 /* Reset pre-scaler & stop RTC */
345 tmp = readb(rtc->regbase + RCR2);
348 writeb(tmp, rtc->regbase + RCR2);
350 writeb(bin2bcd(tm->tm_sec), rtc->regbase + RSECCNT);
351 writeb(bin2bcd(tm->tm_min), rtc->regbase + RMINCNT);
352 writeb(bin2bcd(tm->tm_hour), rtc->regbase + RHRCNT);
353 writeb(bin2bcd(tm->tm_wday), rtc->regbase + RWKCNT);
354 writeb(bin2bcd(tm->tm_mday), rtc->regbase + RDAYCNT);
355 writeb(bin2bcd(tm->tm_mon + 1), rtc->regbase + RMONCNT);
357 if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
358 year = (bin2bcd((tm->tm_year + 1900) / 100) << 8) |
359 bin2bcd(tm->tm_year % 100);
360 writew(year, rtc->regbase + RYRCNT);
362 year = tm->tm_year % 100;
363 writeb(bin2bcd(year), rtc->regbase + RYRCNT);
367 tmp = readb(rtc->regbase + RCR2);
369 tmp |= RCR2_RTCEN | RCR2_START;
370 writeb(tmp, rtc->regbase + RCR2);
372 spin_unlock_irq(&rtc->lock);
377 static inline int sh_rtc_read_alarm_value(struct sh_rtc *rtc, int reg_off)
380 int value = 0xff; /* return 0xff for ignored values */
382 byte = readb(rtc->regbase + reg_off);
384 byte &= ~AR_ENB; /* strip the enable bit */
385 value = bcd2bin(byte);
391 static int sh_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
393 struct sh_rtc *rtc = dev_get_drvdata(dev);
394 struct rtc_time *tm = &wkalrm->time;
396 spin_lock_irq(&rtc->lock);
398 tm->tm_sec = sh_rtc_read_alarm_value(rtc, RSECAR);
399 tm->tm_min = sh_rtc_read_alarm_value(rtc, RMINAR);
400 tm->tm_hour = sh_rtc_read_alarm_value(rtc, RHRAR);
401 tm->tm_wday = sh_rtc_read_alarm_value(rtc, RWKAR);
402 tm->tm_mday = sh_rtc_read_alarm_value(rtc, RDAYAR);
403 tm->tm_mon = sh_rtc_read_alarm_value(rtc, RMONAR);
405 tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */
407 wkalrm->enabled = (readb(rtc->regbase + RCR1) & RCR1_AIE) ? 1 : 0;
409 spin_unlock_irq(&rtc->lock);
414 static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc,
415 int value, int reg_off)
417 /* < 0 for a value that is ignored */
419 writeb(0, rtc->regbase + reg_off);
421 writeb(bin2bcd(value) | AR_ENB, rtc->regbase + reg_off);
424 static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
426 struct sh_rtc *rtc = dev_get_drvdata(dev);
428 struct rtc_time *tm = &wkalrm->time;
431 spin_lock_irq(&rtc->lock);
433 /* disable alarm interrupt and clear the alarm flag */
434 rcr1 = readb(rtc->regbase + RCR1);
435 rcr1 &= ~(RCR1_AF | RCR1_AIE);
436 writeb(rcr1, rtc->regbase + RCR1);
439 sh_rtc_write_alarm_value(rtc, tm->tm_sec, RSECAR);
440 sh_rtc_write_alarm_value(rtc, tm->tm_min, RMINAR);
441 sh_rtc_write_alarm_value(rtc, tm->tm_hour, RHRAR);
442 sh_rtc_write_alarm_value(rtc, tm->tm_wday, RWKAR);
443 sh_rtc_write_alarm_value(rtc, tm->tm_mday, RDAYAR);
447 sh_rtc_write_alarm_value(rtc, mon, RMONAR);
449 if (wkalrm->enabled) {
451 writeb(rcr1, rtc->regbase + RCR1);
454 spin_unlock_irq(&rtc->lock);
459 static const struct rtc_class_ops sh_rtc_ops = {
460 .read_time = sh_rtc_read_time,
461 .set_time = sh_rtc_set_time,
462 .read_alarm = sh_rtc_read_alarm,
463 .set_alarm = sh_rtc_set_alarm,
465 .alarm_irq_enable = sh_rtc_alarm_irq_enable,
468 static int __init sh_rtc_probe(struct platform_device *pdev)
471 struct resource *res;
476 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
480 spin_lock_init(&rtc->lock);
482 /* get periodic/carry/alarm irqs */
483 ret = platform_get_irq(pdev, 0);
484 if (unlikely(ret <= 0)) {
485 dev_err(&pdev->dev, "No IRQ resource\n");
489 rtc->periodic_irq = ret;
490 rtc->carry_irq = platform_get_irq(pdev, 1);
491 rtc->alarm_irq = platform_get_irq(pdev, 2);
493 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
495 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
496 if (unlikely(res == NULL)) {
497 dev_err(&pdev->dev, "No IO resource\n");
501 rtc->regsize = resource_size(res);
503 rtc->res = devm_request_mem_region(&pdev->dev, res->start,
504 rtc->regsize, pdev->name);
505 if (unlikely(!rtc->res))
508 rtc->regbase = devm_ioremap_nocache(&pdev->dev, rtc->res->start,
510 if (unlikely(!rtc->regbase))
513 if (!pdev->dev.of_node) {
515 /* With a single device, the clock id is still "rtc0" */
519 snprintf(clk_name, sizeof(clk_name), "rtc%d", clk_id);
521 snprintf(clk_name, sizeof(clk_name), "fck");
523 rtc->clk = devm_clk_get(&pdev->dev, clk_name);
524 if (IS_ERR(rtc->clk)) {
526 * No error handling for rtc->clk intentionally, not all
527 * platforms will have a unique clock for the RTC, and
528 * the clk API can handle the struct clk pointer being
534 clk_enable(rtc->clk);
536 rtc->capabilities = RTC_DEF_CAPABILITIES;
539 if (dev_get_platdata(&pdev->dev)) {
540 struct sh_rtc_platform_info *pinfo =
541 dev_get_platdata(&pdev->dev);
544 * Some CPUs have special capabilities in addition to the
545 * default set. Add those in here.
547 rtc->capabilities |= pinfo->capabilities;
551 if (rtc->carry_irq <= 0) {
552 /* register shared periodic/carry/alarm irq */
553 ret = devm_request_irq(&pdev->dev, rtc->periodic_irq,
554 sh_rtc_shared, 0, "sh-rtc", rtc);
557 "request IRQ failed with %d, IRQ %d\n", ret,
562 /* register periodic/carry/alarm irqs */
563 ret = devm_request_irq(&pdev->dev, rtc->periodic_irq,
564 sh_rtc_periodic, 0, "sh-rtc period", rtc);
567 "request period IRQ failed with %d, IRQ %d\n",
568 ret, rtc->periodic_irq);
572 ret = devm_request_irq(&pdev->dev, rtc->carry_irq,
573 sh_rtc_interrupt, 0, "sh-rtc carry", rtc);
576 "request carry IRQ failed with %d, IRQ %d\n",
577 ret, rtc->carry_irq);
581 ret = devm_request_irq(&pdev->dev, rtc->alarm_irq,
582 sh_rtc_alarm, 0, "sh-rtc alarm", rtc);
585 "request alarm IRQ failed with %d, IRQ %d\n",
586 ret, rtc->alarm_irq);
591 platform_set_drvdata(pdev, rtc);
593 /* everything disabled by default */
594 sh_rtc_setaie(&pdev->dev, 0);
595 sh_rtc_setcie(&pdev->dev, 0);
597 rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "sh",
598 &sh_rtc_ops, THIS_MODULE);
599 if (IS_ERR(rtc->rtc_dev)) {
600 ret = PTR_ERR(rtc->rtc_dev);
604 rtc->rtc_dev->max_user_freq = 256;
606 /* reset rtc to epoch 0 if time is invalid */
607 if (rtc_read_time(rtc->rtc_dev, &r) < 0) {
608 rtc_time_to_tm(0, &r);
609 rtc_set_time(rtc->rtc_dev, &r);
612 device_init_wakeup(&pdev->dev, 1);
616 clk_disable(rtc->clk);
621 static int __exit sh_rtc_remove(struct platform_device *pdev)
623 struct sh_rtc *rtc = platform_get_drvdata(pdev);
625 sh_rtc_setaie(&pdev->dev, 0);
626 sh_rtc_setcie(&pdev->dev, 0);
628 clk_disable(rtc->clk);
633 static void sh_rtc_set_irq_wake(struct device *dev, int enabled)
635 struct sh_rtc *rtc = dev_get_drvdata(dev);
637 irq_set_irq_wake(rtc->periodic_irq, enabled);
639 if (rtc->carry_irq > 0) {
640 irq_set_irq_wake(rtc->carry_irq, enabled);
641 irq_set_irq_wake(rtc->alarm_irq, enabled);
645 static int __maybe_unused sh_rtc_suspend(struct device *dev)
647 if (device_may_wakeup(dev))
648 sh_rtc_set_irq_wake(dev, 1);
653 static int __maybe_unused sh_rtc_resume(struct device *dev)
655 if (device_may_wakeup(dev))
656 sh_rtc_set_irq_wake(dev, 0);
661 static SIMPLE_DEV_PM_OPS(sh_rtc_pm_ops, sh_rtc_suspend, sh_rtc_resume);
663 static const struct of_device_id sh_rtc_of_match[] = {
664 { .compatible = "renesas,sh-rtc", },
667 MODULE_DEVICE_TABLE(of, sh_rtc_of_match);
669 static struct platform_driver sh_rtc_platform_driver = {
672 .pm = &sh_rtc_pm_ops,
673 .of_match_table = sh_rtc_of_match,
675 .remove = __exit_p(sh_rtc_remove),
678 module_platform_driver_probe(sh_rtc_platform_driver, sh_rtc_probe);
680 MODULE_DESCRIPTION("SuperH on-chip RTC driver");
684 MODULE_LICENSE("GPL");
685 MODULE_ALIAS("platform:" DRV_NAME);