xref: /openbmc/linux/drivers/rtc/rtc-armada38x.c (revision 0c874100)
1 /*
2  * RTC driver for the Armada 38x Marvell SoCs
3  *
4  * Copyright (C) 2015 Marvell
5  *
6  * Gregory Clement <gregory.clement@free-electrons.com>
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of the
11  * License, or (at your option) any later version.
12  *
13  */
14 
15 #include <linux/delay.h>
16 #include <linux/io.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/of_device.h>
20 #include <linux/platform_device.h>
21 #include <linux/rtc.h>
22 
23 #define RTC_STATUS	    0x0
24 #define RTC_STATUS_ALARM1	    BIT(0)
25 #define RTC_STATUS_ALARM2	    BIT(1)
26 #define RTC_IRQ1_CONF	    0x4
27 #define RTC_IRQ2_CONF	    0x8
28 #define RTC_IRQ_AL_EN		    BIT(0)
29 #define RTC_IRQ_FREQ_EN		    BIT(1)
30 #define RTC_IRQ_FREQ_1HZ	    BIT(2)
31 #define RTC_CCR		    0x18
32 #define RTC_CCR_MODE		    BIT(15)
33 #define RTC_CONF_TEST	    0x1C
34 #define RTC_NOMINAL_TIMING	    BIT(13)
35 
36 #define RTC_TIME	    0xC
37 #define RTC_ALARM1	    0x10
38 #define RTC_ALARM2	    0x14
39 
40 /* Armada38x SoC registers  */
41 #define RTC_38X_BRIDGE_TIMING_CTL   0x0
42 #define RTC_38X_PERIOD_OFFS		0
43 #define RTC_38X_PERIOD_MASK		(0x3FF << RTC_38X_PERIOD_OFFS)
44 #define RTC_38X_READ_DELAY_OFFS		26
45 #define RTC_38X_READ_DELAY_MASK		(0x1F << RTC_38X_READ_DELAY_OFFS)
46 
47 /* Armada 7K/8K registers  */
48 #define RTC_8K_BRIDGE_TIMING_CTL0    0x0
49 #define RTC_8K_WRCLK_PERIOD_OFFS	0
50 #define RTC_8K_WRCLK_PERIOD_MASK	(0xFFFF << RTC_8K_WRCLK_PERIOD_OFFS)
51 #define RTC_8K_WRCLK_SETUP_OFFS		16
52 #define RTC_8K_WRCLK_SETUP_MASK		(0xFFFF << RTC_8K_WRCLK_SETUP_OFFS)
53 #define RTC_8K_BRIDGE_TIMING_CTL1   0x4
54 #define RTC_8K_READ_DELAY_OFFS		0
55 #define RTC_8K_READ_DELAY_MASK		(0xFFFF << RTC_8K_READ_DELAY_OFFS)
56 
57 #define RTC_8K_ISR		    0x10
58 #define RTC_8K_IMR		    0x14
59 #define RTC_8K_ALARM2			BIT(0)
60 
61 #define SOC_RTC_INTERRUPT	    0x8
62 #define SOC_RTC_ALARM1			BIT(0)
63 #define SOC_RTC_ALARM2			BIT(1)
64 #define SOC_RTC_ALARM1_MASK		BIT(2)
65 #define SOC_RTC_ALARM2_MASK		BIT(3)
66 
67 #define SAMPLE_NR 100
68 
69 struct value_to_freq {
70 	u32 value;
71 	u8 freq;
72 };
73 
74 struct armada38x_rtc {
75 	struct rtc_device   *rtc_dev;
76 	void __iomem	    *regs;
77 	void __iomem	    *regs_soc;
78 	spinlock_t	    lock;
79 	int		    irq;
80 	bool		    initialized;
81 	struct value_to_freq *val_to_freq;
82 	struct armada38x_rtc_data *data;
83 };
84 
85 #define ALARM1	0
86 #define ALARM2	1
87 
88 #define ALARM_REG(base, alarm)	 ((base) + (alarm) * sizeof(u32))
89 
90 struct armada38x_rtc_data {
91 	/* Initialize the RTC-MBUS bridge timing */
92 	void (*update_mbus_timing)(struct armada38x_rtc *rtc);
93 	u32 (*read_rtc_reg)(struct armada38x_rtc *rtc, u8 rtc_reg);
94 	void (*clear_isr)(struct armada38x_rtc *rtc);
95 	void (*unmask_interrupt)(struct armada38x_rtc *rtc);
96 	u32 alarm;
97 };
98 
99 /*
100  * According to the datasheet, the OS should wait 5us after every
101  * register write to the RTC hard macro so that the required update
102  * can occur without holding off the system bus
103  * According to errata RES-3124064, Write to any RTC register
104  * may fail. As a workaround, before writing to RTC
105  * register, issue a dummy write of 0x0 twice to RTC Status
106  * register.
107  */
108 
109 static void rtc_delayed_write(u32 val, struct armada38x_rtc *rtc, int offset)
110 {
111 	writel(0, rtc->regs + RTC_STATUS);
112 	writel(0, rtc->regs + RTC_STATUS);
113 	writel(val, rtc->regs + offset);
114 	udelay(5);
115 }
116 
117 /* Update RTC-MBUS bridge timing parameters */
118 static void rtc_update_38x_mbus_timing_params(struct armada38x_rtc *rtc)
119 {
120 	u32 reg;
121 
122 	reg = readl(rtc->regs_soc + RTC_38X_BRIDGE_TIMING_CTL);
123 	reg &= ~RTC_38X_PERIOD_MASK;
124 	reg |= 0x3FF << RTC_38X_PERIOD_OFFS; /* Maximum value */
125 	reg &= ~RTC_38X_READ_DELAY_MASK;
126 	reg |= 0x1F << RTC_38X_READ_DELAY_OFFS; /* Maximum value */
127 	writel(reg, rtc->regs_soc + RTC_38X_BRIDGE_TIMING_CTL);
128 }
129 
130 static void rtc_update_8k_mbus_timing_params(struct armada38x_rtc *rtc)
131 {
132 	u32 reg;
133 
134 	reg = readl(rtc->regs_soc + RTC_8K_BRIDGE_TIMING_CTL0);
135 	reg &= ~RTC_8K_WRCLK_PERIOD_MASK;
136 	reg |= 0x3FF << RTC_8K_WRCLK_PERIOD_OFFS;
137 	reg &= ~RTC_8K_WRCLK_SETUP_MASK;
138 	reg |= 0x29 << RTC_8K_WRCLK_SETUP_OFFS;
139 	writel(reg, rtc->regs_soc + RTC_8K_BRIDGE_TIMING_CTL0);
140 
141 	reg = readl(rtc->regs_soc + RTC_8K_BRIDGE_TIMING_CTL1);
142 	reg &= ~RTC_8K_READ_DELAY_MASK;
143 	reg |= 0x3F << RTC_8K_READ_DELAY_OFFS;
144 	writel(reg, rtc->regs_soc + RTC_8K_BRIDGE_TIMING_CTL1);
145 }
146 
147 static u32 read_rtc_register(struct armada38x_rtc *rtc, u8 rtc_reg)
148 {
149 	return readl(rtc->regs + rtc_reg);
150 }
151 
152 static u32 read_rtc_register_38x_wa(struct armada38x_rtc *rtc, u8 rtc_reg)
153 {
154 	int i, index_max = 0, max = 0;
155 
156 	for (i = 0; i < SAMPLE_NR; i++) {
157 		rtc->val_to_freq[i].value = readl(rtc->regs + rtc_reg);
158 		rtc->val_to_freq[i].freq = 0;
159 	}
160 
161 	for (i = 0; i < SAMPLE_NR; i++) {
162 		int j = 0;
163 		u32 value = rtc->val_to_freq[i].value;
164 
165 		while (rtc->val_to_freq[j].freq) {
166 			if (rtc->val_to_freq[j].value == value) {
167 				rtc->val_to_freq[j].freq++;
168 				break;
169 			}
170 			j++;
171 		}
172 
173 		if (!rtc->val_to_freq[j].freq) {
174 			rtc->val_to_freq[j].value = value;
175 			rtc->val_to_freq[j].freq = 1;
176 		}
177 
178 		if (rtc->val_to_freq[j].freq > max) {
179 			index_max = j;
180 			max = rtc->val_to_freq[j].freq;
181 		}
182 
183 		/*
184 		 * If a value already has half of the sample this is the most
185 		 * frequent one and we can stop the research right now
186 		 */
187 		if (max > SAMPLE_NR / 2)
188 			break;
189 	}
190 
191 	return rtc->val_to_freq[index_max].value;
192 }
193 
194 static void armada38x_clear_isr(struct armada38x_rtc *rtc)
195 {
196 	u32 val = readl(rtc->regs_soc + SOC_RTC_INTERRUPT);
197 
198 	writel(val & ~SOC_RTC_ALARM1, rtc->regs_soc + SOC_RTC_INTERRUPT);
199 }
200 
201 static void armada38x_unmask_interrupt(struct armada38x_rtc *rtc)
202 {
203 	u32 val = readl(rtc->regs_soc + SOC_RTC_INTERRUPT);
204 
205 	writel(val | SOC_RTC_ALARM1_MASK, rtc->regs_soc + SOC_RTC_INTERRUPT);
206 }
207 
208 static void armada8k_clear_isr(struct armada38x_rtc *rtc)
209 {
210 	writel(RTC_8K_ALARM2, rtc->regs_soc + RTC_8K_ISR);
211 }
212 
213 static void armada8k_unmask_interrupt(struct armada38x_rtc *rtc)
214 {
215 	writel(RTC_8K_ALARM2, rtc->regs_soc + RTC_8K_IMR);
216 }
217 
218 static int armada38x_rtc_read_time(struct device *dev, struct rtc_time *tm)
219 {
220 	struct armada38x_rtc *rtc = dev_get_drvdata(dev);
221 	unsigned long time, flags;
222 
223 	spin_lock_irqsave(&rtc->lock, flags);
224 	time = rtc->data->read_rtc_reg(rtc, RTC_TIME);
225 	spin_unlock_irqrestore(&rtc->lock, flags);
226 
227 	rtc_time64_to_tm(time, tm);
228 
229 	return 0;
230 }
231 
232 static void armada38x_rtc_reset(struct armada38x_rtc *rtc)
233 {
234 	u32 reg;
235 
236 	reg = rtc->data->read_rtc_reg(rtc, RTC_CONF_TEST);
237 	/* If bits [7:0] are non-zero, assume RTC was uninitialized */
238 	if (reg & 0xff) {
239 		rtc_delayed_write(0, rtc, RTC_CONF_TEST);
240 		msleep(500); /* Oscillator startup time */
241 		rtc_delayed_write(0, rtc, RTC_TIME);
242 		rtc_delayed_write(SOC_RTC_ALARM1 | SOC_RTC_ALARM2, rtc,
243 				  RTC_STATUS);
244 		rtc_delayed_write(RTC_NOMINAL_TIMING, rtc, RTC_CCR);
245 	}
246 	rtc->initialized = true;
247 }
248 
249 static int armada38x_rtc_set_time(struct device *dev, struct rtc_time *tm)
250 {
251 	struct armada38x_rtc *rtc = dev_get_drvdata(dev);
252 	unsigned long time, flags;
253 
254 	time = rtc_tm_to_time64(tm);
255 
256 	if (!rtc->initialized)
257 		armada38x_rtc_reset(rtc);
258 
259 	spin_lock_irqsave(&rtc->lock, flags);
260 	rtc_delayed_write(time, rtc, RTC_TIME);
261 	spin_unlock_irqrestore(&rtc->lock, flags);
262 
263 	return 0;
264 }
265 
266 static int armada38x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
267 {
268 	struct armada38x_rtc *rtc = dev_get_drvdata(dev);
269 	unsigned long time, flags;
270 	u32 reg = ALARM_REG(RTC_ALARM1, rtc->data->alarm);
271 	u32 reg_irq = ALARM_REG(RTC_IRQ1_CONF, rtc->data->alarm);
272 	u32 val;
273 
274 	spin_lock_irqsave(&rtc->lock, flags);
275 
276 	time = rtc->data->read_rtc_reg(rtc, reg);
277 	val = rtc->data->read_rtc_reg(rtc, reg_irq) & RTC_IRQ_AL_EN;
278 
279 	spin_unlock_irqrestore(&rtc->lock, flags);
280 
281 	alrm->enabled = val ? 1 : 0;
282 	rtc_time64_to_tm(time,  &alrm->time);
283 
284 	return 0;
285 }
286 
287 static int armada38x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
288 {
289 	struct armada38x_rtc *rtc = dev_get_drvdata(dev);
290 	u32 reg = ALARM_REG(RTC_ALARM1, rtc->data->alarm);
291 	u32 reg_irq = ALARM_REG(RTC_IRQ1_CONF, rtc->data->alarm);
292 	unsigned long time, flags;
293 
294 	time = rtc_tm_to_time64(&alrm->time);
295 
296 	spin_lock_irqsave(&rtc->lock, flags);
297 
298 	rtc_delayed_write(time, rtc, reg);
299 
300 	if (alrm->enabled) {
301 		rtc_delayed_write(RTC_IRQ_AL_EN, rtc, reg_irq);
302 		rtc->data->unmask_interrupt(rtc);
303 	}
304 
305 	spin_unlock_irqrestore(&rtc->lock, flags);
306 
307 	return 0;
308 }
309 
310 static int armada38x_rtc_alarm_irq_enable(struct device *dev,
311 					 unsigned int enabled)
312 {
313 	struct armada38x_rtc *rtc = dev_get_drvdata(dev);
314 	u32 reg_irq = ALARM_REG(RTC_IRQ1_CONF, rtc->data->alarm);
315 	unsigned long flags;
316 
317 	spin_lock_irqsave(&rtc->lock, flags);
318 
319 	if (enabled)
320 		rtc_delayed_write(RTC_IRQ_AL_EN, rtc, reg_irq);
321 	else
322 		rtc_delayed_write(0, rtc, reg_irq);
323 
324 	spin_unlock_irqrestore(&rtc->lock, flags);
325 
326 	return 0;
327 }
328 
329 static irqreturn_t armada38x_rtc_alarm_irq(int irq, void *data)
330 {
331 	struct armada38x_rtc *rtc = data;
332 	u32 val;
333 	int event = RTC_IRQF | RTC_AF;
334 	u32 reg_irq = ALARM_REG(RTC_IRQ1_CONF, rtc->data->alarm);
335 
336 	dev_dbg(&rtc->rtc_dev->dev, "%s:irq(%d)\n", __func__, irq);
337 
338 	spin_lock(&rtc->lock);
339 
340 	rtc->data->clear_isr(rtc);
341 	val = rtc->data->read_rtc_reg(rtc, reg_irq);
342 	/* disable all the interrupts for alarm*/
343 	rtc_delayed_write(0, rtc, reg_irq);
344 	/* Ack the event */
345 	rtc_delayed_write(1 << rtc->data->alarm, rtc, RTC_STATUS);
346 
347 	spin_unlock(&rtc->lock);
348 
349 	if (val & RTC_IRQ_FREQ_EN) {
350 		if (val & RTC_IRQ_FREQ_1HZ)
351 			event |= RTC_UF;
352 		else
353 			event |= RTC_PF;
354 	}
355 
356 	rtc_update_irq(rtc->rtc_dev, 1, event);
357 
358 	return IRQ_HANDLED;
359 }
360 
361 /*
362  * The information given in the Armada 388 functional spec is complex.
363  * They give two different formulas for calculating the offset value,
364  * but when considering "Offset" as an 8-bit signed integer, they both
365  * reduce down to (we shall rename "Offset" as "val" here):
366  *
367  *   val = (f_ideal / f_measured - 1) / resolution   where f_ideal = 32768
368  *
369  * Converting to time, f = 1/t:
370  *   val = (t_measured / t_ideal - 1) / resolution   where t_ideal = 1/32768
371  *
372  *   =>  t_measured / t_ideal = val * resolution + 1
373  *
374  * "offset" in the RTC interface is defined as:
375  *   t = t0 * (1 + offset * 1e-9)
376  * where t is the desired period, t0 is the measured period with a zero
377  * offset, which is t_measured above. With t0 = t_measured and t = t_ideal,
378  *   offset = (t_ideal / t_measured - 1) / 1e-9
379  *
380  *   => t_ideal / t_measured = offset * 1e-9 + 1
381  *
382  * so:
383  *
384  *   offset * 1e-9 + 1 = 1 / (val * resolution + 1)
385  *
386  * We want "resolution" to be an integer, so resolution = R * 1e-9, giving
387  *   offset = 1e18 / (val * R + 1e9) - 1e9
388  *   val = (1e18 / (offset + 1e9) - 1e9) / R
389  * with a common transformation:
390  *   f(x) = 1e18 / (x + 1e9) - 1e9
391  *   offset = f(val * R)
392  *   val = f(offset) / R
393  *
394  * Armada 38x supports two modes, fine mode (954ppb) and coarse mode (3815ppb).
395  */
396 static long armada38x_ppb_convert(long ppb)
397 {
398 	long div = ppb + 1000000000L;
399 
400 	return div_s64(1000000000000000000LL + div / 2, div) - 1000000000L;
401 }
402 
403 static int armada38x_rtc_read_offset(struct device *dev, long *offset)
404 {
405 	struct armada38x_rtc *rtc = dev_get_drvdata(dev);
406 	unsigned long ccr, flags;
407 	long ppb_cor;
408 
409 	spin_lock_irqsave(&rtc->lock, flags);
410 	ccr = rtc->data->read_rtc_reg(rtc, RTC_CCR);
411 	spin_unlock_irqrestore(&rtc->lock, flags);
412 
413 	ppb_cor = (ccr & RTC_CCR_MODE ? 3815 : 954) * (s8)ccr;
414 	/* ppb_cor + 1000000000L can never be zero */
415 	*offset = armada38x_ppb_convert(ppb_cor);
416 
417 	return 0;
418 }
419 
420 static int armada38x_rtc_set_offset(struct device *dev, long offset)
421 {
422 	struct armada38x_rtc *rtc = dev_get_drvdata(dev);
423 	unsigned long ccr = 0;
424 	long ppb_cor, off;
425 
426 	/*
427 	 * The maximum ppb_cor is -128 * 3815 .. 127 * 3815, but we
428 	 * need to clamp the input.  This equates to -484270 .. 488558.
429 	 * Not only is this to stop out of range "off" but also to
430 	 * avoid the division by zero in armada38x_ppb_convert().
431 	 */
432 	offset = clamp(offset, -484270L, 488558L);
433 
434 	ppb_cor = armada38x_ppb_convert(offset);
435 
436 	/*
437 	 * Use low update mode where possible, which gives a better
438 	 * resolution of correction.
439 	 */
440 	off = DIV_ROUND_CLOSEST(ppb_cor, 954);
441 	if (off > 127 || off < -128) {
442 		ccr = RTC_CCR_MODE;
443 		off = DIV_ROUND_CLOSEST(ppb_cor, 3815);
444 	}
445 
446 	/*
447 	 * Armada 388 requires a bit pattern in bits 14..8 depending on
448 	 * the sign bit: { 0, ~S, S, S, S, S, S }
449 	 */
450 	ccr |= (off & 0x3fff) ^ 0x2000;
451 	rtc_delayed_write(ccr, rtc, RTC_CCR);
452 
453 	return 0;
454 }
455 
456 static const struct rtc_class_ops armada38x_rtc_ops = {
457 	.read_time = armada38x_rtc_read_time,
458 	.set_time = armada38x_rtc_set_time,
459 	.read_alarm = armada38x_rtc_read_alarm,
460 	.set_alarm = armada38x_rtc_set_alarm,
461 	.alarm_irq_enable = armada38x_rtc_alarm_irq_enable,
462 	.read_offset = armada38x_rtc_read_offset,
463 	.set_offset = armada38x_rtc_set_offset,
464 };
465 
466 static const struct rtc_class_ops armada38x_rtc_ops_noirq = {
467 	.read_time = armada38x_rtc_read_time,
468 	.set_time = armada38x_rtc_set_time,
469 	.read_alarm = armada38x_rtc_read_alarm,
470 	.read_offset = armada38x_rtc_read_offset,
471 	.set_offset = armada38x_rtc_set_offset,
472 };
473 
474 static const struct armada38x_rtc_data armada38x_data = {
475 	.update_mbus_timing = rtc_update_38x_mbus_timing_params,
476 	.read_rtc_reg = read_rtc_register_38x_wa,
477 	.clear_isr = armada38x_clear_isr,
478 	.unmask_interrupt = armada38x_unmask_interrupt,
479 	.alarm = ALARM1,
480 };
481 
482 static const struct armada38x_rtc_data armada8k_data = {
483 	.update_mbus_timing = rtc_update_8k_mbus_timing_params,
484 	.read_rtc_reg = read_rtc_register,
485 	.clear_isr = armada8k_clear_isr,
486 	.unmask_interrupt = armada8k_unmask_interrupt,
487 	.alarm = ALARM2,
488 };
489 
490 #ifdef CONFIG_OF
491 static const struct of_device_id armada38x_rtc_of_match_table[] = {
492 	{
493 		.compatible = "marvell,armada-380-rtc",
494 		.data = &armada38x_data,
495 	},
496 	{
497 		.compatible = "marvell,armada-8k-rtc",
498 		.data = &armada8k_data,
499 	},
500 	{}
501 };
502 MODULE_DEVICE_TABLE(of, armada38x_rtc_of_match_table);
503 #endif
504 
505 static __init int armada38x_rtc_probe(struct platform_device *pdev)
506 {
507 	struct resource *res;
508 	struct armada38x_rtc *rtc;
509 	const struct of_device_id *match;
510 	int ret;
511 
512 	match = of_match_device(armada38x_rtc_of_match_table, &pdev->dev);
513 	if (!match)
514 		return -ENODEV;
515 
516 	rtc = devm_kzalloc(&pdev->dev, sizeof(struct armada38x_rtc),
517 			    GFP_KERNEL);
518 	if (!rtc)
519 		return -ENOMEM;
520 
521 	rtc->val_to_freq = devm_kcalloc(&pdev->dev, SAMPLE_NR,
522 				sizeof(struct value_to_freq), GFP_KERNEL);
523 	if (!rtc->val_to_freq)
524 		return -ENOMEM;
525 
526 	spin_lock_init(&rtc->lock);
527 
528 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rtc");
529 	rtc->regs = devm_ioremap_resource(&pdev->dev, res);
530 	if (IS_ERR(rtc->regs))
531 		return PTR_ERR(rtc->regs);
532 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rtc-soc");
533 	rtc->regs_soc = devm_ioremap_resource(&pdev->dev, res);
534 	if (IS_ERR(rtc->regs_soc))
535 		return PTR_ERR(rtc->regs_soc);
536 
537 	rtc->irq = platform_get_irq(pdev, 0);
538 
539 	if (rtc->irq < 0) {
540 		dev_err(&pdev->dev, "no irq\n");
541 		return rtc->irq;
542 	}
543 
544 	rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
545 	if (IS_ERR(rtc->rtc_dev))
546 		return PTR_ERR(rtc->rtc_dev);
547 
548 	if (devm_request_irq(&pdev->dev, rtc->irq, armada38x_rtc_alarm_irq,
549 				0, pdev->name, rtc) < 0) {
550 		dev_warn(&pdev->dev, "Interrupt not available.\n");
551 		rtc->irq = -1;
552 	}
553 	platform_set_drvdata(pdev, rtc);
554 
555 	if (rtc->irq != -1) {
556 		device_init_wakeup(&pdev->dev, 1);
557 		rtc->rtc_dev->ops = &armada38x_rtc_ops;
558 	} else {
559 		/*
560 		 * If there is no interrupt available then we can't
561 		 * use the alarm
562 		 */
563 		rtc->rtc_dev->ops = &armada38x_rtc_ops_noirq;
564 	}
565 	rtc->data = (struct armada38x_rtc_data *)match->data;
566 
567 	/* Update RTC-MBUS bridge timing parameters */
568 	rtc->data->update_mbus_timing(rtc);
569 
570 	rtc->rtc_dev->range_max = U32_MAX;
571 
572 	ret = rtc_register_device(rtc->rtc_dev);
573 	if (ret)
574 		dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
575 
576 	return ret;
577 }
578 
579 #ifdef CONFIG_PM_SLEEP
580 static int armada38x_rtc_suspend(struct device *dev)
581 {
582 	if (device_may_wakeup(dev)) {
583 		struct armada38x_rtc *rtc = dev_get_drvdata(dev);
584 
585 		return enable_irq_wake(rtc->irq);
586 	}
587 
588 	return 0;
589 }
590 
591 static int armada38x_rtc_resume(struct device *dev)
592 {
593 	if (device_may_wakeup(dev)) {
594 		struct armada38x_rtc *rtc = dev_get_drvdata(dev);
595 
596 		/* Update RTC-MBUS bridge timing parameters */
597 		rtc->data->update_mbus_timing(rtc);
598 
599 		return disable_irq_wake(rtc->irq);
600 	}
601 
602 	return 0;
603 }
604 #endif
605 
606 static SIMPLE_DEV_PM_OPS(armada38x_rtc_pm_ops,
607 			 armada38x_rtc_suspend, armada38x_rtc_resume);
608 
609 static struct platform_driver armada38x_rtc_driver = {
610 	.driver		= {
611 		.name	= "armada38x-rtc",
612 		.pm	= &armada38x_rtc_pm_ops,
613 		.of_match_table = of_match_ptr(armada38x_rtc_of_match_table),
614 	},
615 };
616 
617 module_platform_driver_probe(armada38x_rtc_driver, armada38x_rtc_probe);
618 
619 MODULE_DESCRIPTION("Marvell Armada 38x RTC driver");
620 MODULE_AUTHOR("Gregory CLEMENT <gregory.clement@free-electrons.com>");
621 MODULE_LICENSE("GPL");
622