xref: /openbmc/linux/drivers/rtc/rtc-omap.c (revision 588b48ca)
1 /*
2  * TI OMAP1 Real Time Clock interface for Linux
3  *
4  * Copyright (C) 2003 MontaVista Software, Inc.
5  * Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com>
6  *
7  * Copyright (C) 2006 David Brownell (new RTC framework)
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License
11  * as published by the Free Software Foundation; either version
12  * 2 of the License, or (at your option) any later version.
13  */
14 
15 #include <linux/kernel.h>
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/ioport.h>
19 #include <linux/delay.h>
20 #include <linux/rtc.h>
21 #include <linux/bcd.h>
22 #include <linux/platform_device.h>
23 #include <linux/of.h>
24 #include <linux/of_device.h>
25 #include <linux/pm_runtime.h>
26 #include <linux/io.h>
27 
28 /* The OMAP1 RTC is a year/month/day/hours/minutes/seconds BCD clock
29  * with century-range alarm matching, driven by the 32kHz clock.
30  *
31  * The main user-visible ways it differs from PC RTCs are by omitting
32  * "don't care" alarm fields and sub-second periodic IRQs, and having
33  * an autoadjust mechanism to calibrate to the true oscillator rate.
34  *
35  * Board-specific wiring options include using split power mode with
36  * RTC_OFF_NOFF used as the reset signal (so the RTC won't be reset),
37  * and wiring RTC_WAKE_INT (so the RTC alarm can wake the system from
38  * low power modes) for OMAP1 boards (OMAP-L138 has this built into
39  * the SoC). See the BOARD-SPECIFIC CUSTOMIZATION comment.
40  */
41 
42 #define	DRIVER_NAME			"omap_rtc"
43 
44 #define OMAP_RTC_BASE			0xfffb4800
45 
46 /* RTC registers */
47 #define OMAP_RTC_SECONDS_REG		0x00
48 #define OMAP_RTC_MINUTES_REG		0x04
49 #define OMAP_RTC_HOURS_REG		0x08
50 #define OMAP_RTC_DAYS_REG		0x0C
51 #define OMAP_RTC_MONTHS_REG		0x10
52 #define OMAP_RTC_YEARS_REG		0x14
53 #define OMAP_RTC_WEEKS_REG		0x18
54 
55 #define OMAP_RTC_ALARM_SECONDS_REG	0x20
56 #define OMAP_RTC_ALARM_MINUTES_REG	0x24
57 #define OMAP_RTC_ALARM_HOURS_REG	0x28
58 #define OMAP_RTC_ALARM_DAYS_REG		0x2c
59 #define OMAP_RTC_ALARM_MONTHS_REG	0x30
60 #define OMAP_RTC_ALARM_YEARS_REG	0x34
61 
62 #define OMAP_RTC_CTRL_REG		0x40
63 #define OMAP_RTC_STATUS_REG		0x44
64 #define OMAP_RTC_INTERRUPTS_REG		0x48
65 
66 #define OMAP_RTC_COMP_LSB_REG		0x4c
67 #define OMAP_RTC_COMP_MSB_REG		0x50
68 #define OMAP_RTC_OSC_REG		0x54
69 
70 #define OMAP_RTC_KICK0_REG		0x6c
71 #define OMAP_RTC_KICK1_REG		0x70
72 
73 #define OMAP_RTC_IRQWAKEEN		0x7c
74 
75 /* OMAP_RTC_CTRL_REG bit fields: */
76 #define OMAP_RTC_CTRL_SPLIT		BIT(7)
77 #define OMAP_RTC_CTRL_DISABLE		BIT(6)
78 #define OMAP_RTC_CTRL_SET_32_COUNTER	BIT(5)
79 #define OMAP_RTC_CTRL_TEST		BIT(4)
80 #define OMAP_RTC_CTRL_MODE_12_24	BIT(3)
81 #define OMAP_RTC_CTRL_AUTO_COMP		BIT(2)
82 #define OMAP_RTC_CTRL_ROUND_30S		BIT(1)
83 #define OMAP_RTC_CTRL_STOP		BIT(0)
84 
85 /* OMAP_RTC_STATUS_REG bit fields: */
86 #define OMAP_RTC_STATUS_POWER_UP	BIT(7)
87 #define OMAP_RTC_STATUS_ALARM		BIT(6)
88 #define OMAP_RTC_STATUS_1D_EVENT	BIT(5)
89 #define OMAP_RTC_STATUS_1H_EVENT	BIT(4)
90 #define OMAP_RTC_STATUS_1M_EVENT	BIT(3)
91 #define OMAP_RTC_STATUS_1S_EVENT	BIT(2)
92 #define OMAP_RTC_STATUS_RUN		BIT(1)
93 #define OMAP_RTC_STATUS_BUSY		BIT(0)
94 
95 /* OMAP_RTC_INTERRUPTS_REG bit fields: */
96 #define OMAP_RTC_INTERRUPTS_IT_ALARM	BIT(3)
97 #define OMAP_RTC_INTERRUPTS_IT_TIMER	BIT(2)
98 
99 /* OMAP_RTC_OSC_REG bit fields: */
100 #define OMAP_RTC_OSC_32KCLK_EN		BIT(6)
101 
102 /* OMAP_RTC_IRQWAKEEN bit fields: */
103 #define OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN	BIT(1)
104 
105 /* OMAP_RTC_KICKER values */
106 #define	KICK0_VALUE			0x83e70b13
107 #define	KICK1_VALUE			0x95a4f1e0
108 
109 #define	OMAP_RTC_HAS_KICKER		BIT(0)
110 
111 /*
112  * Few RTC IP revisions has special WAKE-EN Register to enable Wakeup
113  * generation for event Alarm.
114  */
115 #define	OMAP_RTC_HAS_IRQWAKEEN		BIT(1)
116 
117 /*
118  * Some RTC IP revisions (like those in AM335x and DRA7x) need
119  * the 32KHz clock to be explicitly enabled.
120  */
121 #define OMAP_RTC_HAS_32KCLK_EN		BIT(2)
122 
123 static void __iomem	*rtc_base;
124 
125 #define rtc_read(addr)		readb(rtc_base + (addr))
126 #define rtc_write(val, addr)	writeb(val, rtc_base + (addr))
127 
128 #define rtc_writel(val, addr)	writel(val, rtc_base + (addr))
129 
130 
131 /* we rely on the rtc framework to handle locking (rtc->ops_lock),
132  * so the only other requirement is that register accesses which
133  * require BUSY to be clear are made with IRQs locally disabled
134  */
135 static void rtc_wait_not_busy(void)
136 {
137 	int	count = 0;
138 	u8	status;
139 
140 	/* BUSY may stay active for 1/32768 second (~30 usec) */
141 	for (count = 0; count < 50; count++) {
142 		status = rtc_read(OMAP_RTC_STATUS_REG);
143 		if ((status & (u8)OMAP_RTC_STATUS_BUSY) == 0)
144 			break;
145 		udelay(1);
146 	}
147 	/* now we have ~15 usec to read/write various registers */
148 }
149 
150 static irqreturn_t rtc_irq(int irq, void *rtc)
151 {
152 	unsigned long		events = 0;
153 	u8			irq_data;
154 
155 	irq_data = rtc_read(OMAP_RTC_STATUS_REG);
156 
157 	/* alarm irq? */
158 	if (irq_data & OMAP_RTC_STATUS_ALARM) {
159 		rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
160 		events |= RTC_IRQF | RTC_AF;
161 	}
162 
163 	/* 1/sec periodic/update irq? */
164 	if (irq_data & OMAP_RTC_STATUS_1S_EVENT)
165 		events |= RTC_IRQF | RTC_UF;
166 
167 	rtc_update_irq(rtc, 1, events);
168 
169 	return IRQ_HANDLED;
170 }
171 
172 static int omap_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
173 {
174 	u8 reg, irqwake_reg = 0;
175 	struct platform_device *pdev = to_platform_device(dev);
176 	const struct platform_device_id *id_entry =
177 					platform_get_device_id(pdev);
178 
179 	local_irq_disable();
180 	rtc_wait_not_busy();
181 	reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
182 	if (id_entry->driver_data & OMAP_RTC_HAS_IRQWAKEEN)
183 		irqwake_reg = rtc_read(OMAP_RTC_IRQWAKEEN);
184 
185 	if (enabled) {
186 		reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
187 		irqwake_reg |= OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
188 	} else {
189 		reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
190 		irqwake_reg &= ~OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
191 	}
192 	rtc_wait_not_busy();
193 	rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
194 	if (id_entry->driver_data & OMAP_RTC_HAS_IRQWAKEEN)
195 		rtc_write(irqwake_reg, OMAP_RTC_IRQWAKEEN);
196 	local_irq_enable();
197 
198 	return 0;
199 }
200 
201 /* this hardware doesn't support "don't care" alarm fields */
202 static int tm2bcd(struct rtc_time *tm)
203 {
204 	if (rtc_valid_tm(tm) != 0)
205 		return -EINVAL;
206 
207 	tm->tm_sec = bin2bcd(tm->tm_sec);
208 	tm->tm_min = bin2bcd(tm->tm_min);
209 	tm->tm_hour = bin2bcd(tm->tm_hour);
210 	tm->tm_mday = bin2bcd(tm->tm_mday);
211 
212 	tm->tm_mon = bin2bcd(tm->tm_mon + 1);
213 
214 	/* epoch == 1900 */
215 	if (tm->tm_year < 100 || tm->tm_year > 199)
216 		return -EINVAL;
217 	tm->tm_year = bin2bcd(tm->tm_year - 100);
218 
219 	return 0;
220 }
221 
222 static void bcd2tm(struct rtc_time *tm)
223 {
224 	tm->tm_sec = bcd2bin(tm->tm_sec);
225 	tm->tm_min = bcd2bin(tm->tm_min);
226 	tm->tm_hour = bcd2bin(tm->tm_hour);
227 	tm->tm_mday = bcd2bin(tm->tm_mday);
228 	tm->tm_mon = bcd2bin(tm->tm_mon) - 1;
229 	/* epoch == 1900 */
230 	tm->tm_year = bcd2bin(tm->tm_year) + 100;
231 }
232 
233 
234 static int omap_rtc_read_time(struct device *dev, struct rtc_time *tm)
235 {
236 	/* we don't report wday/yday/isdst ... */
237 	local_irq_disable();
238 	rtc_wait_not_busy();
239 
240 	tm->tm_sec = rtc_read(OMAP_RTC_SECONDS_REG);
241 	tm->tm_min = rtc_read(OMAP_RTC_MINUTES_REG);
242 	tm->tm_hour = rtc_read(OMAP_RTC_HOURS_REG);
243 	tm->tm_mday = rtc_read(OMAP_RTC_DAYS_REG);
244 	tm->tm_mon = rtc_read(OMAP_RTC_MONTHS_REG);
245 	tm->tm_year = rtc_read(OMAP_RTC_YEARS_REG);
246 
247 	local_irq_enable();
248 
249 	bcd2tm(tm);
250 	return 0;
251 }
252 
253 static int omap_rtc_set_time(struct device *dev, struct rtc_time *tm)
254 {
255 	if (tm2bcd(tm) < 0)
256 		return -EINVAL;
257 	local_irq_disable();
258 	rtc_wait_not_busy();
259 
260 	rtc_write(tm->tm_year, OMAP_RTC_YEARS_REG);
261 	rtc_write(tm->tm_mon, OMAP_RTC_MONTHS_REG);
262 	rtc_write(tm->tm_mday, OMAP_RTC_DAYS_REG);
263 	rtc_write(tm->tm_hour, OMAP_RTC_HOURS_REG);
264 	rtc_write(tm->tm_min, OMAP_RTC_MINUTES_REG);
265 	rtc_write(tm->tm_sec, OMAP_RTC_SECONDS_REG);
266 
267 	local_irq_enable();
268 
269 	return 0;
270 }
271 
272 static int omap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
273 {
274 	local_irq_disable();
275 	rtc_wait_not_busy();
276 
277 	alm->time.tm_sec = rtc_read(OMAP_RTC_ALARM_SECONDS_REG);
278 	alm->time.tm_min = rtc_read(OMAP_RTC_ALARM_MINUTES_REG);
279 	alm->time.tm_hour = rtc_read(OMAP_RTC_ALARM_HOURS_REG);
280 	alm->time.tm_mday = rtc_read(OMAP_RTC_ALARM_DAYS_REG);
281 	alm->time.tm_mon = rtc_read(OMAP_RTC_ALARM_MONTHS_REG);
282 	alm->time.tm_year = rtc_read(OMAP_RTC_ALARM_YEARS_REG);
283 
284 	local_irq_enable();
285 
286 	bcd2tm(&alm->time);
287 	alm->enabled = !!(rtc_read(OMAP_RTC_INTERRUPTS_REG)
288 			& OMAP_RTC_INTERRUPTS_IT_ALARM);
289 
290 	return 0;
291 }
292 
293 static int omap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
294 {
295 	u8 reg, irqwake_reg = 0;
296 	struct platform_device *pdev = to_platform_device(dev);
297 	const struct platform_device_id *id_entry =
298 					platform_get_device_id(pdev);
299 
300 	if (tm2bcd(&alm->time) < 0)
301 		return -EINVAL;
302 
303 	local_irq_disable();
304 	rtc_wait_not_busy();
305 
306 	rtc_write(alm->time.tm_year, OMAP_RTC_ALARM_YEARS_REG);
307 	rtc_write(alm->time.tm_mon, OMAP_RTC_ALARM_MONTHS_REG);
308 	rtc_write(alm->time.tm_mday, OMAP_RTC_ALARM_DAYS_REG);
309 	rtc_write(alm->time.tm_hour, OMAP_RTC_ALARM_HOURS_REG);
310 	rtc_write(alm->time.tm_min, OMAP_RTC_ALARM_MINUTES_REG);
311 	rtc_write(alm->time.tm_sec, OMAP_RTC_ALARM_SECONDS_REG);
312 
313 	reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
314 	if (id_entry->driver_data & OMAP_RTC_HAS_IRQWAKEEN)
315 		irqwake_reg = rtc_read(OMAP_RTC_IRQWAKEEN);
316 
317 	if (alm->enabled) {
318 		reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
319 		irqwake_reg |= OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
320 	} else {
321 		reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
322 		irqwake_reg &= ~OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
323 	}
324 	rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
325 	if (id_entry->driver_data & OMAP_RTC_HAS_IRQWAKEEN)
326 		rtc_write(irqwake_reg, OMAP_RTC_IRQWAKEEN);
327 
328 	local_irq_enable();
329 
330 	return 0;
331 }
332 
333 static struct rtc_class_ops omap_rtc_ops = {
334 	.read_time	= omap_rtc_read_time,
335 	.set_time	= omap_rtc_set_time,
336 	.read_alarm	= omap_rtc_read_alarm,
337 	.set_alarm	= omap_rtc_set_alarm,
338 	.alarm_irq_enable = omap_rtc_alarm_irq_enable,
339 };
340 
341 static int omap_rtc_alarm;
342 static int omap_rtc_timer;
343 
344 #define	OMAP_RTC_DATA_AM3352_IDX	1
345 #define	OMAP_RTC_DATA_DA830_IDX		2
346 
347 static struct platform_device_id omap_rtc_devtype[] = {
348 	{
349 		.name	= DRIVER_NAME,
350 	},
351 	[OMAP_RTC_DATA_AM3352_IDX] = {
352 		.name	= "am3352-rtc",
353 		.driver_data = OMAP_RTC_HAS_KICKER | OMAP_RTC_HAS_IRQWAKEEN |
354 			       OMAP_RTC_HAS_32KCLK_EN,
355 	},
356 	[OMAP_RTC_DATA_DA830_IDX] = {
357 		.name	= "da830-rtc",
358 		.driver_data = OMAP_RTC_HAS_KICKER,
359 	},
360 	{},
361 };
362 MODULE_DEVICE_TABLE(platform, omap_rtc_devtype);
363 
364 static const struct of_device_id omap_rtc_of_match[] = {
365 	{	.compatible	= "ti,da830-rtc",
366 		.data		= &omap_rtc_devtype[OMAP_RTC_DATA_DA830_IDX],
367 	},
368 	{	.compatible	= "ti,am3352-rtc",
369 		.data		= &omap_rtc_devtype[OMAP_RTC_DATA_AM3352_IDX],
370 	},
371 	{},
372 };
373 MODULE_DEVICE_TABLE(of, omap_rtc_of_match);
374 
375 static int __init omap_rtc_probe(struct platform_device *pdev)
376 {
377 	struct resource		*res;
378 	struct rtc_device	*rtc;
379 	u8			reg, new_ctrl;
380 	const struct platform_device_id *id_entry;
381 	const struct of_device_id *of_id;
382 
383 	of_id = of_match_device(omap_rtc_of_match, &pdev->dev);
384 	if (of_id)
385 		pdev->id_entry = of_id->data;
386 
387 	id_entry = platform_get_device_id(pdev);
388 	if (!id_entry) {
389 		dev_err(&pdev->dev, "no matching device entry\n");
390 		return -ENODEV;
391 	}
392 
393 	omap_rtc_timer = platform_get_irq(pdev, 0);
394 	if (omap_rtc_timer <= 0) {
395 		pr_debug("%s: no update irq?\n", pdev->name);
396 		return -ENOENT;
397 	}
398 
399 	omap_rtc_alarm = platform_get_irq(pdev, 1);
400 	if (omap_rtc_alarm <= 0) {
401 		pr_debug("%s: no alarm irq?\n", pdev->name);
402 		return -ENOENT;
403 	}
404 
405 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
406 	rtc_base = devm_ioremap_resource(&pdev->dev, res);
407 	if (IS_ERR(rtc_base))
408 		return PTR_ERR(rtc_base);
409 
410 	/* Enable the clock/module so that we can access the registers */
411 	pm_runtime_enable(&pdev->dev);
412 	pm_runtime_get_sync(&pdev->dev);
413 
414 	if (id_entry->driver_data & OMAP_RTC_HAS_KICKER) {
415 		rtc_writel(KICK0_VALUE, OMAP_RTC_KICK0_REG);
416 		rtc_writel(KICK1_VALUE, OMAP_RTC_KICK1_REG);
417 	}
418 
419 	rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
420 			&omap_rtc_ops, THIS_MODULE);
421 	if (IS_ERR(rtc)) {
422 		pr_debug("%s: can't register RTC device, err %ld\n",
423 			pdev->name, PTR_ERR(rtc));
424 		goto fail0;
425 	}
426 	platform_set_drvdata(pdev, rtc);
427 
428 	/* clear pending irqs, and set 1/second periodic,
429 	 * which we'll use instead of update irqs
430 	 */
431 	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
432 
433 	/* enable RTC functional clock */
434 	if (id_entry->driver_data & OMAP_RTC_HAS_32KCLK_EN)
435 		rtc_writel(OMAP_RTC_OSC_32KCLK_EN, OMAP_RTC_OSC_REG);
436 
437 	/* clear old status */
438 	reg = rtc_read(OMAP_RTC_STATUS_REG);
439 	if (reg & (u8) OMAP_RTC_STATUS_POWER_UP) {
440 		pr_info("%s: RTC power up reset detected\n",
441 			pdev->name);
442 		rtc_write(OMAP_RTC_STATUS_POWER_UP, OMAP_RTC_STATUS_REG);
443 	}
444 	if (reg & (u8) OMAP_RTC_STATUS_ALARM)
445 		rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
446 
447 	/* handle periodic and alarm irqs */
448 	if (devm_request_irq(&pdev->dev, omap_rtc_timer, rtc_irq, 0,
449 			dev_name(&rtc->dev), rtc)) {
450 		pr_debug("%s: RTC timer interrupt IRQ%d already claimed\n",
451 			pdev->name, omap_rtc_timer);
452 		goto fail0;
453 	}
454 	if ((omap_rtc_timer != omap_rtc_alarm) &&
455 		(devm_request_irq(&pdev->dev, omap_rtc_alarm, rtc_irq, 0,
456 			dev_name(&rtc->dev), rtc))) {
457 		pr_debug("%s: RTC alarm interrupt IRQ%d already claimed\n",
458 			pdev->name, omap_rtc_alarm);
459 		goto fail0;
460 	}
461 
462 	/* On boards with split power, RTC_ON_NOFF won't reset the RTC */
463 	reg = rtc_read(OMAP_RTC_CTRL_REG);
464 	if (reg & (u8) OMAP_RTC_CTRL_STOP)
465 		pr_info("%s: already running\n", pdev->name);
466 
467 	/* force to 24 hour mode */
468 	new_ctrl = reg & (OMAP_RTC_CTRL_SPLIT|OMAP_RTC_CTRL_AUTO_COMP);
469 	new_ctrl |= OMAP_RTC_CTRL_STOP;
470 
471 	/* BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE:
472 	 *
473 	 *  - Device wake-up capability setting should come through chip
474 	 *    init logic. OMAP1 boards should initialize the "wakeup capable"
475 	 *    flag in the platform device if the board is wired right for
476 	 *    being woken up by RTC alarm. For OMAP-L138, this capability
477 	 *    is built into the SoC by the "Deep Sleep" capability.
478 	 *
479 	 *  - Boards wired so RTC_ON_nOFF is used as the reset signal,
480 	 *    rather than nPWRON_RESET, should forcibly enable split
481 	 *    power mode.  (Some chip errata report that RTC_CTRL_SPLIT
482 	 *    is write-only, and always reads as zero...)
483 	 */
484 
485 	device_init_wakeup(&pdev->dev, true);
486 
487 	if (new_ctrl & (u8) OMAP_RTC_CTRL_SPLIT)
488 		pr_info("%s: split power mode\n", pdev->name);
489 
490 	if (reg != new_ctrl)
491 		rtc_write(new_ctrl, OMAP_RTC_CTRL_REG);
492 
493 	return 0;
494 
495 fail0:
496 	if (id_entry->driver_data & OMAP_RTC_HAS_KICKER)
497 		rtc_writel(0, OMAP_RTC_KICK0_REG);
498 	pm_runtime_put_sync(&pdev->dev);
499 	pm_runtime_disable(&pdev->dev);
500 	return -EIO;
501 }
502 
503 static int __exit omap_rtc_remove(struct platform_device *pdev)
504 {
505 	const struct platform_device_id *id_entry =
506 				platform_get_device_id(pdev);
507 
508 	device_init_wakeup(&pdev->dev, 0);
509 
510 	/* leave rtc running, but disable irqs */
511 	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
512 
513 	if (id_entry->driver_data & OMAP_RTC_HAS_KICKER)
514 		rtc_writel(0, OMAP_RTC_KICK0_REG);
515 
516 	/* Disable the clock/module */
517 	pm_runtime_put_sync(&pdev->dev);
518 	pm_runtime_disable(&pdev->dev);
519 
520 	return 0;
521 }
522 
523 #ifdef CONFIG_PM_SLEEP
524 static u8 irqstat;
525 
526 static int omap_rtc_suspend(struct device *dev)
527 {
528 	irqstat = rtc_read(OMAP_RTC_INTERRUPTS_REG);
529 
530 	/* FIXME the RTC alarm is not currently acting as a wakeup event
531 	 * source on some platforms, and in fact this enable() call is just
532 	 * saving a flag that's never used...
533 	 */
534 	if (device_may_wakeup(dev))
535 		enable_irq_wake(omap_rtc_alarm);
536 	else
537 		rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
538 
539 	/* Disable the clock/module */
540 	pm_runtime_put_sync(dev);
541 
542 	return 0;
543 }
544 
545 static int omap_rtc_resume(struct device *dev)
546 {
547 	/* Enable the clock/module so that we can access the registers */
548 	pm_runtime_get_sync(dev);
549 
550 	if (device_may_wakeup(dev))
551 		disable_irq_wake(omap_rtc_alarm);
552 	else
553 		rtc_write(irqstat, OMAP_RTC_INTERRUPTS_REG);
554 
555 	return 0;
556 }
557 #endif
558 
559 static SIMPLE_DEV_PM_OPS(omap_rtc_pm_ops, omap_rtc_suspend, omap_rtc_resume);
560 
561 static void omap_rtc_shutdown(struct platform_device *pdev)
562 {
563 	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
564 }
565 
566 MODULE_ALIAS("platform:omap_rtc");
567 static struct platform_driver omap_rtc_driver = {
568 	.remove		= __exit_p(omap_rtc_remove),
569 	.shutdown	= omap_rtc_shutdown,
570 	.driver		= {
571 		.name	= DRIVER_NAME,
572 		.owner	= THIS_MODULE,
573 		.pm	= &omap_rtc_pm_ops,
574 		.of_match_table = omap_rtc_of_match,
575 	},
576 	.id_table	= omap_rtc_devtype,
577 };
578 
579 module_platform_driver_probe(omap_rtc_driver, omap_rtc_probe);
580 
581 MODULE_AUTHOR("George G. Davis (and others)");
582 MODULE_LICENSE("GPL");
583