1/*
2 *	Real Time Clock interface for Linux on Atmel AT91RM9200
3 *
4 *	Copyright (C) 2002 Rick Bronson
5 *
6 *	Converted to RTC class model by Andrew Victor
7 *
8 *	Ported to Linux 2.6 by Steven Scholz
9 *	Based on s3c2410-rtc.c Simtec Electronics
10 *
11 *	Based on sa1100-rtc.c by Nils Faerber
12 *	Based on rtc.c by Paul Gortmaker
13 *
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.
18 *
19 */
20
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/ioctl.h>
29#include <linux/completion.h>
30
31#include <asm/uaccess.h>
32#include <asm/rtc.h>
33
34#include <asm/mach/time.h>
35
36#include <asm/arch/at91_rtc.h>
37
38
39#define AT91_RTC_FREQ		1
40#define AT91_RTC_EPOCH		1900UL	/* just like arch/arm/common/rtctime.c */
41
42static DECLARE_COMPLETION(at91_rtc_updated);
43static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
44
45/*
46 * Decode time/date into rtc_time structure
47 */
48static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
49				struct rtc_time *tm)
50{
51	unsigned int time, date;
52
53	/* must read twice in case it changes */
54	do {
55		time = at91_sys_read(timereg);
56		date = at91_sys_read(calreg);
57	} while ((time != at91_sys_read(timereg)) ||
58			(date != at91_sys_read(calreg)));
59
60	tm->tm_sec  = BCD2BIN((time & AT91_RTC_SEC) >> 0);
61	tm->tm_min  = BCD2BIN((time & AT91_RTC_MIN) >> 8);
62	tm->tm_hour = BCD2BIN((time & AT91_RTC_HOUR) >> 16);
63
64	/*
65	 * The Calendar Alarm register does not have a field for
66	 * the year - so these will return an invalid value.  When an
67	 * alarm is set, at91_alarm_year wille store the current year.
68	 */
69	tm->tm_year  = BCD2BIN(date & AT91_RTC_CENT) * 100;	/* century */
70	tm->tm_year += BCD2BIN((date & AT91_RTC_YEAR) >> 8);	/* year */
71
72	tm->tm_wday = BCD2BIN((date & AT91_RTC_DAY) >> 21) - 1;	/* day of the week [0-6], Sunday=0 */
73	tm->tm_mon  = BCD2BIN((date & AT91_RTC_MONTH) >> 16) - 1;
74	tm->tm_mday = BCD2BIN((date & AT91_RTC_DATE) >> 24);
75}
76
77/*
78 * Read current time and date in RTC
79 */
80static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
81{
82	at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
83	tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
84	tm->tm_year = tm->tm_year - 1900;
85
86	pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
87		1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
88		tm->tm_hour, tm->tm_min, tm->tm_sec);
89
90	return 0;
91}
92
93/*
94 * Set current time and date in RTC
95 */
96static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
97{
98	unsigned long cr;
99
100	pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
101		1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
102		tm->tm_hour, tm->tm_min, tm->tm_sec);
103
104	/* Stop Time/Calendar from counting */
105	cr = at91_sys_read(AT91_RTC_CR);
106	at91_sys_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
107
108	at91_sys_write(AT91_RTC_IER, AT91_RTC_ACKUPD);
109	wait_for_completion(&at91_rtc_updated);	/* wait for ACKUPD interrupt */
110	at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD);
111
112	at91_sys_write(AT91_RTC_TIMR,
113			  BIN2BCD(tm->tm_sec) << 0
114			| BIN2BCD(tm->tm_min) << 8
115			| BIN2BCD(tm->tm_hour) << 16);
116
117	at91_sys_write(AT91_RTC_CALR,
118			  BIN2BCD((tm->tm_year + 1900) / 100)	/* century */
119			| BIN2BCD(tm->tm_year % 100) << 8	/* year */
120			| BIN2BCD(tm->tm_mon + 1) << 16		/* tm_mon starts at zero */
121			| BIN2BCD(tm->tm_wday + 1) << 21	/* day of the week [0-6], Sunday=0 */
122			| BIN2BCD(tm->tm_mday) << 24);
123
124	/* Restart Time/Calendar */
125	cr = at91_sys_read(AT91_RTC_CR);
126	at91_sys_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
127
128	return 0;
129}
130
131/*
132 * Read alarm time and date in RTC
133 */
134static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
135{
136	struct rtc_time *tm = &alrm->time;
137
138	at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
139	tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
140	tm->tm_year = at91_alarm_year - 1900;
141
142	alrm->enabled = (at91_sys_read(AT91_RTC_IMR) & AT91_RTC_ALARM)
143			? 1 : 0;
144
145	pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
146		1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
147		tm->tm_hour, tm->tm_min, tm->tm_sec);
148
149	return 0;
150}
151
152/*
153 * Set alarm time and date in RTC
154 */
155static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
156{
157	struct rtc_time tm;
158
159	at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm);
160
161	at91_alarm_year = tm.tm_year;
162
163	tm.tm_hour = alrm->time.tm_hour;
164	tm.tm_min = alrm->time.tm_min;
165	tm.tm_sec = alrm->time.tm_sec;
166
167	at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
168	at91_sys_write(AT91_RTC_TIMALR,
169		  BIN2BCD(tm.tm_sec) << 0
170		| BIN2BCD(tm.tm_min) << 8
171		| BIN2BCD(tm.tm_hour) << 16
172		| AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
173	at91_sys_write(AT91_RTC_CALALR,
174		  BIN2BCD(tm.tm_mon + 1) << 16		/* tm_mon starts at zero */
175		| BIN2BCD(tm.tm_mday) << 24
176		| AT91_RTC_DATEEN | AT91_RTC_MTHEN);
177
178	if (alrm->enabled)
179		at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
180
181	pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
182		at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
183		tm.tm_min, tm.tm_sec);
184
185	return 0;
186}
187
188/*
189 * Handle commands from user-space
190 */
191static int at91_rtc_ioctl(struct device *dev, unsigned int cmd,
192			unsigned long arg)
193{
194	int ret = 0;
195
196	pr_debug("%s(): cmd=%08x, arg=%08lx.\n", __FUNCTION__, cmd, arg);
197
198	switch (cmd) {
199	case RTC_AIE_OFF:	/* alarm off */
200		at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
201		break;
202	case RTC_AIE_ON:	/* alarm on */
203		at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
204		break;
205	case RTC_UIE_OFF:	/* update off */
206	case RTC_PIE_OFF:	/* periodic off */
207		at91_sys_write(AT91_RTC_IDR, AT91_RTC_SECEV);
208		break;
209	case RTC_UIE_ON:	/* update on */
210	case RTC_PIE_ON:	/* periodic on */
211		at91_sys_write(AT91_RTC_IER, AT91_RTC_SECEV);
212		break;
213	case RTC_IRQP_READ:	/* read periodic alarm frequency */
214		ret = put_user(AT91_RTC_FREQ, (unsigned long *) arg);
215		break;
216	case RTC_IRQP_SET:	/* set periodic alarm frequency */
217		if (arg != AT91_RTC_FREQ)
218			ret = -EINVAL;
219		break;
220	default:
221		ret = -ENOIOCTLCMD;
222		break;
223	}
224
225	return ret;
226}
227
228/*
229 * Provide additional RTC information in /proc/driver/rtc
230 */
231static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
232{
233	unsigned long imr = at91_sys_read(AT91_RTC_IMR);
234
235	seq_printf(seq, "update_IRQ\t: %s\n",
236			(imr & AT91_RTC_ACKUPD) ? "yes" : "no");
237	seq_printf(seq, "periodic_IRQ\t: %s\n",
238			(imr & AT91_RTC_SECEV) ? "yes" : "no");
239	seq_printf(seq, "periodic_freq\t: %ld\n",
240			(unsigned long) AT91_RTC_FREQ);
241
242	return 0;
243}
244
245/*
246 * IRQ handler for the RTC
247 */
248static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
249{
250	struct platform_device *pdev = dev_id;
251	struct rtc_device *rtc = platform_get_drvdata(pdev);
252	unsigned int rtsr;
253	unsigned long events = 0;
254
255	rtsr = at91_sys_read(AT91_RTC_SR) & at91_sys_read(AT91_RTC_IMR);
256	if (rtsr) {		/* this interrupt is shared!  Is it ours? */
257		if (rtsr & AT91_RTC_ALARM)
258			events |= (RTC_AF | RTC_IRQF);
259		if (rtsr & AT91_RTC_SECEV)
260			events |= (RTC_UF | RTC_IRQF);
261		if (rtsr & AT91_RTC_ACKUPD)
262			complete(&at91_rtc_updated);
263
264		at91_sys_write(AT91_RTC_SCCR, rtsr);	/* clear status reg */
265
266		rtc_update_irq(rtc, 1, events);
267
268		pr_debug("%s(): num=%ld, events=0x%02lx\n", __FUNCTION__,
269			events >> 8, events & 0x000000FF);
270
271		return IRQ_HANDLED;
272	}
273	return IRQ_NONE;		/* not handled */
274}
275
276static const struct rtc_class_ops at91_rtc_ops = {
277	.ioctl		= at91_rtc_ioctl,
278	.read_time	= at91_rtc_readtime,
279	.set_time	= at91_rtc_settime,
280	.read_alarm	= at91_rtc_readalarm,
281	.set_alarm	= at91_rtc_setalarm,
282	.proc		= at91_rtc_proc,
283};
284
285/*
286 * Initialize and install RTC driver
287 */
288static int __init at91_rtc_probe(struct platform_device *pdev)
289{
290	struct rtc_device *rtc;
291	int ret;
292
293	at91_sys_write(AT91_RTC_CR, 0);
294	at91_sys_write(AT91_RTC_MR, 0);		/* 24 hour mode */
295
296	/* Disable all interrupts */
297	at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
298					AT91_RTC_SECEV | AT91_RTC_TIMEV |
299					AT91_RTC_CALEV);
300
301	ret = request_irq(AT91_ID_SYS, at91_rtc_interrupt,
302				IRQF_DISABLED | IRQF_SHARED,
303				"at91_rtc", pdev);
304	if (ret) {
305		printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n",
306				AT91_ID_SYS);
307		return ret;
308	}
309
310	/* cpu init code should really have flagged this device as
311	 * being wake-capable; if it didn't, do that here.
312	 */
313	if (!device_can_wakeup(&pdev->dev))
314		device_init_wakeup(&pdev->dev, 1);
315
316	rtc = rtc_device_register(pdev->name, &pdev->dev,
317				&at91_rtc_ops, THIS_MODULE);
318	if (IS_ERR(rtc)) {
319		free_irq(AT91_ID_SYS, pdev);
320		return PTR_ERR(rtc);
321	}
322	platform_set_drvdata(pdev, rtc);
323
324	printk(KERN_INFO "AT91 Real Time Clock driver.\n");
325	return 0;
326}
327
328/*
329 * Disable and remove the RTC driver
330 */
331static int __exit at91_rtc_remove(struct platform_device *pdev)
332{
333	struct rtc_device *rtc = platform_get_drvdata(pdev);
334
335	/* Disable all interrupts */
336	at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
337					AT91_RTC_SECEV | AT91_RTC_TIMEV |
338					AT91_RTC_CALEV);
339	free_irq(AT91_ID_SYS, pdev);
340
341	rtc_device_unregister(rtc);
342	platform_set_drvdata(pdev, NULL);
343
344	return 0;
345}
346
347#ifdef CONFIG_PM
348
349/* AT91RM9200 RTC Power management control */
350
351static u32 at91_rtc_imr;
352
353static int at91_rtc_suspend(struct platform_device *pdev, pm_message_t state)
354{
355	/* this IRQ is shared with DBGU and other hardware which isn't
356	 * necessarily doing PM like we are...
357	 */
358	at91_rtc_imr = at91_sys_read(AT91_RTC_IMR)
359			& (AT91_RTC_ALARM|AT91_RTC_SECEV);
360	if (at91_rtc_imr) {
361		if (device_may_wakeup(&pdev->dev))
362			enable_irq_wake(AT91_ID_SYS);
363		else
364			at91_sys_write(AT91_RTC_IDR, at91_rtc_imr);
365	}
366	return 0;
367}
368
369static int at91_rtc_resume(struct platform_device *pdev)
370{
371	if (at91_rtc_imr) {
372		if (device_may_wakeup(&pdev->dev))
373			disable_irq_wake(AT91_ID_SYS);
374		else
375			at91_sys_write(AT91_RTC_IER, at91_rtc_imr);
376	}
377	return 0;
378}
379#else
380#define at91_rtc_suspend NULL
381#define at91_rtc_resume  NULL
382#endif
383
384static struct platform_driver at91_rtc_driver = {
385	.remove		= __exit_p(at91_rtc_remove),
386	.suspend	= at91_rtc_suspend,
387	.resume		= at91_rtc_resume,
388	.driver		= {
389		.name	= "at91_rtc",
390		.owner	= THIS_MODULE,
391	},
392};
393
394static int __init at91_rtc_init(void)
395{
396	return platform_driver_probe(&at91_rtc_driver, at91_rtc_probe);
397}
398
399static void __exit at91_rtc_exit(void)
400{
401	platform_driver_unregister(&at91_rtc_driver);
402}
403
404module_init(at91_rtc_init);
405module_exit(at91_rtc_exit);
406
407MODULE_AUTHOR("Rick Bronson");
408MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
409MODULE_LICENSE("GPL");
410