xref: /openbmc/linux/drivers/rtc/rtc-omap.c (revision e3b9f1e8)
1 /*
2  * TI OMAP 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  * Copyright (C) 2014 Johan Hovold <johan@kernel.org>
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License
12  * as published by the Free Software Foundation; either version
13  * 2 of the License, or (at your option) any later version.
14  */
15 
16 #include <dt-bindings/gpio/gpio.h>
17 #include <linux/bcd.h>
18 #include <linux/clk.h>
19 #include <linux/delay.h>
20 #include <linux/init.h>
21 #include <linux/io.h>
22 #include <linux/ioport.h>
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/of.h>
26 #include <linux/of_device.h>
27 #include <linux/pinctrl/pinctrl.h>
28 #include <linux/pinctrl/pinconf.h>
29 #include <linux/pinctrl/pinconf-generic.h>
30 #include <linux/platform_device.h>
31 #include <linux/pm_runtime.h>
32 #include <linux/rtc.h>
33 
34 /*
35  * The OMAP RTC is a year/month/day/hours/minutes/seconds BCD clock
36  * with century-range alarm matching, driven by the 32kHz clock.
37  *
38  * The main user-visible ways it differs from PC RTCs are by omitting
39  * "don't care" alarm fields and sub-second periodic IRQs, and having
40  * an autoadjust mechanism to calibrate to the true oscillator rate.
41  *
42  * Board-specific wiring options include using split power mode with
43  * RTC_OFF_NOFF used as the reset signal (so the RTC won't be reset),
44  * and wiring RTC_WAKE_INT (so the RTC alarm can wake the system from
45  * low power modes) for OMAP1 boards (OMAP-L138 has this built into
46  * the SoC). See the BOARD-SPECIFIC CUSTOMIZATION comment.
47  */
48 
49 /* RTC registers */
50 #define OMAP_RTC_SECONDS_REG		0x00
51 #define OMAP_RTC_MINUTES_REG		0x04
52 #define OMAP_RTC_HOURS_REG		0x08
53 #define OMAP_RTC_DAYS_REG		0x0C
54 #define OMAP_RTC_MONTHS_REG		0x10
55 #define OMAP_RTC_YEARS_REG		0x14
56 #define OMAP_RTC_WEEKS_REG		0x18
57 
58 #define OMAP_RTC_ALARM_SECONDS_REG	0x20
59 #define OMAP_RTC_ALARM_MINUTES_REG	0x24
60 #define OMAP_RTC_ALARM_HOURS_REG	0x28
61 #define OMAP_RTC_ALARM_DAYS_REG		0x2c
62 #define OMAP_RTC_ALARM_MONTHS_REG	0x30
63 #define OMAP_RTC_ALARM_YEARS_REG	0x34
64 
65 #define OMAP_RTC_CTRL_REG		0x40
66 #define OMAP_RTC_STATUS_REG		0x44
67 #define OMAP_RTC_INTERRUPTS_REG		0x48
68 
69 #define OMAP_RTC_COMP_LSB_REG		0x4c
70 #define OMAP_RTC_COMP_MSB_REG		0x50
71 #define OMAP_RTC_OSC_REG		0x54
72 
73 #define OMAP_RTC_SCRATCH0_REG		0x60
74 #define OMAP_RTC_SCRATCH1_REG		0x64
75 #define OMAP_RTC_SCRATCH2_REG		0x68
76 
77 #define OMAP_RTC_KICK0_REG		0x6c
78 #define OMAP_RTC_KICK1_REG		0x70
79 
80 #define OMAP_RTC_IRQWAKEEN		0x7c
81 
82 #define OMAP_RTC_ALARM2_SECONDS_REG	0x80
83 #define OMAP_RTC_ALARM2_MINUTES_REG	0x84
84 #define OMAP_RTC_ALARM2_HOURS_REG	0x88
85 #define OMAP_RTC_ALARM2_DAYS_REG	0x8c
86 #define OMAP_RTC_ALARM2_MONTHS_REG	0x90
87 #define OMAP_RTC_ALARM2_YEARS_REG	0x94
88 
89 #define OMAP_RTC_PMIC_REG		0x98
90 
91 /* OMAP_RTC_CTRL_REG bit fields: */
92 #define OMAP_RTC_CTRL_SPLIT		BIT(7)
93 #define OMAP_RTC_CTRL_DISABLE		BIT(6)
94 #define OMAP_RTC_CTRL_SET_32_COUNTER	BIT(5)
95 #define OMAP_RTC_CTRL_TEST		BIT(4)
96 #define OMAP_RTC_CTRL_MODE_12_24	BIT(3)
97 #define OMAP_RTC_CTRL_AUTO_COMP		BIT(2)
98 #define OMAP_RTC_CTRL_ROUND_30S		BIT(1)
99 #define OMAP_RTC_CTRL_STOP		BIT(0)
100 
101 /* OMAP_RTC_STATUS_REG bit fields: */
102 #define OMAP_RTC_STATUS_POWER_UP	BIT(7)
103 #define OMAP_RTC_STATUS_ALARM2		BIT(7)
104 #define OMAP_RTC_STATUS_ALARM		BIT(6)
105 #define OMAP_RTC_STATUS_1D_EVENT	BIT(5)
106 #define OMAP_RTC_STATUS_1H_EVENT	BIT(4)
107 #define OMAP_RTC_STATUS_1M_EVENT	BIT(3)
108 #define OMAP_RTC_STATUS_1S_EVENT	BIT(2)
109 #define OMAP_RTC_STATUS_RUN		BIT(1)
110 #define OMAP_RTC_STATUS_BUSY		BIT(0)
111 
112 /* OMAP_RTC_INTERRUPTS_REG bit fields: */
113 #define OMAP_RTC_INTERRUPTS_IT_ALARM2	BIT(4)
114 #define OMAP_RTC_INTERRUPTS_IT_ALARM	BIT(3)
115 #define OMAP_RTC_INTERRUPTS_IT_TIMER	BIT(2)
116 
117 /* OMAP_RTC_OSC_REG bit fields: */
118 #define OMAP_RTC_OSC_32KCLK_EN		BIT(6)
119 #define OMAP_RTC_OSC_SEL_32KCLK_SRC	BIT(3)
120 #define OMAP_RTC_OSC_OSC32K_GZ_DISABLE	BIT(4)
121 
122 /* OMAP_RTC_IRQWAKEEN bit fields: */
123 #define OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN	BIT(1)
124 
125 /* OMAP_RTC_PMIC bit fields: */
126 #define OMAP_RTC_PMIC_POWER_EN_EN	BIT(16)
127 #define OMAP_RTC_PMIC_EXT_WKUP_EN(x)	BIT(x)
128 #define OMAP_RTC_PMIC_EXT_WKUP_POL(x)	BIT(4 + x)
129 
130 /* OMAP_RTC_KICKER values */
131 #define	KICK0_VALUE			0x83e70b13
132 #define	KICK1_VALUE			0x95a4f1e0
133 
134 struct omap_rtc;
135 
136 struct omap_rtc_device_type {
137 	bool has_32kclk_en;
138 	bool has_irqwakeen;
139 	bool has_pmic_mode;
140 	bool has_power_up_reset;
141 	void (*lock)(struct omap_rtc *rtc);
142 	void (*unlock)(struct omap_rtc *rtc);
143 };
144 
145 struct omap_rtc {
146 	struct rtc_device *rtc;
147 	void __iomem *base;
148 	struct clk *clk;
149 	int irq_alarm;
150 	int irq_timer;
151 	u8 interrupts_reg;
152 	bool is_pmic_controller;
153 	bool has_ext_clk;
154 	bool is_suspending;
155 	const struct omap_rtc_device_type *type;
156 	struct pinctrl_dev *pctldev;
157 };
158 
159 static inline u8 rtc_read(struct omap_rtc *rtc, unsigned int reg)
160 {
161 	return readb(rtc->base + reg);
162 }
163 
164 static inline u32 rtc_readl(struct omap_rtc *rtc, unsigned int reg)
165 {
166 	return readl(rtc->base + reg);
167 }
168 
169 static inline void rtc_write(struct omap_rtc *rtc, unsigned int reg, u8 val)
170 {
171 	writeb(val, rtc->base + reg);
172 }
173 
174 static inline void rtc_writel(struct omap_rtc *rtc, unsigned int reg, u32 val)
175 {
176 	writel(val, rtc->base + reg);
177 }
178 
179 static void am3352_rtc_unlock(struct omap_rtc *rtc)
180 {
181 	rtc_writel(rtc, OMAP_RTC_KICK0_REG, KICK0_VALUE);
182 	rtc_writel(rtc, OMAP_RTC_KICK1_REG, KICK1_VALUE);
183 }
184 
185 static void am3352_rtc_lock(struct omap_rtc *rtc)
186 {
187 	rtc_writel(rtc, OMAP_RTC_KICK0_REG, 0);
188 	rtc_writel(rtc, OMAP_RTC_KICK1_REG, 0);
189 }
190 
191 static void default_rtc_unlock(struct omap_rtc *rtc)
192 {
193 }
194 
195 static void default_rtc_lock(struct omap_rtc *rtc)
196 {
197 }
198 
199 /*
200  * We rely on the rtc framework to handle locking (rtc->ops_lock),
201  * so the only other requirement is that register accesses which
202  * require BUSY to be clear are made with IRQs locally disabled
203  */
204 static void rtc_wait_not_busy(struct omap_rtc *rtc)
205 {
206 	int count;
207 	u8 status;
208 
209 	/* BUSY may stay active for 1/32768 second (~30 usec) */
210 	for (count = 0; count < 50; count++) {
211 		status = rtc_read(rtc, OMAP_RTC_STATUS_REG);
212 		if (!(status & OMAP_RTC_STATUS_BUSY))
213 			break;
214 		udelay(1);
215 	}
216 	/* now we have ~15 usec to read/write various registers */
217 }
218 
219 static irqreturn_t rtc_irq(int irq, void *dev_id)
220 {
221 	struct omap_rtc	*rtc = dev_id;
222 	unsigned long events = 0;
223 	u8 irq_data;
224 
225 	irq_data = rtc_read(rtc, OMAP_RTC_STATUS_REG);
226 
227 	/* alarm irq? */
228 	if (irq_data & OMAP_RTC_STATUS_ALARM) {
229 		rtc->type->unlock(rtc);
230 		rtc_write(rtc, OMAP_RTC_STATUS_REG, OMAP_RTC_STATUS_ALARM);
231 		rtc->type->lock(rtc);
232 		events |= RTC_IRQF | RTC_AF;
233 	}
234 
235 	/* 1/sec periodic/update irq? */
236 	if (irq_data & OMAP_RTC_STATUS_1S_EVENT)
237 		events |= RTC_IRQF | RTC_UF;
238 
239 	rtc_update_irq(rtc->rtc, 1, events);
240 
241 	return IRQ_HANDLED;
242 }
243 
244 static int omap_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
245 {
246 	struct omap_rtc *rtc = dev_get_drvdata(dev);
247 	u8 reg, irqwake_reg = 0;
248 
249 	local_irq_disable();
250 	rtc_wait_not_busy(rtc);
251 	reg = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
252 	if (rtc->type->has_irqwakeen)
253 		irqwake_reg = rtc_read(rtc, OMAP_RTC_IRQWAKEEN);
254 
255 	if (enabled) {
256 		reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
257 		irqwake_reg |= OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
258 	} else {
259 		reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
260 		irqwake_reg &= ~OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
261 	}
262 	rtc_wait_not_busy(rtc);
263 	rtc->type->unlock(rtc);
264 	rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, reg);
265 	if (rtc->type->has_irqwakeen)
266 		rtc_write(rtc, OMAP_RTC_IRQWAKEEN, irqwake_reg);
267 	rtc->type->lock(rtc);
268 	local_irq_enable();
269 
270 	return 0;
271 }
272 
273 /* this hardware doesn't support "don't care" alarm fields */
274 static int tm2bcd(struct rtc_time *tm)
275 {
276 	if (rtc_valid_tm(tm) != 0)
277 		return -EINVAL;
278 
279 	tm->tm_sec = bin2bcd(tm->tm_sec);
280 	tm->tm_min = bin2bcd(tm->tm_min);
281 	tm->tm_hour = bin2bcd(tm->tm_hour);
282 	tm->tm_mday = bin2bcd(tm->tm_mday);
283 
284 	tm->tm_mon = bin2bcd(tm->tm_mon + 1);
285 
286 	/* epoch == 1900 */
287 	if (tm->tm_year < 100 || tm->tm_year > 199)
288 		return -EINVAL;
289 	tm->tm_year = bin2bcd(tm->tm_year - 100);
290 
291 	return 0;
292 }
293 
294 static void bcd2tm(struct rtc_time *tm)
295 {
296 	tm->tm_sec = bcd2bin(tm->tm_sec);
297 	tm->tm_min = bcd2bin(tm->tm_min);
298 	tm->tm_hour = bcd2bin(tm->tm_hour);
299 	tm->tm_mday = bcd2bin(tm->tm_mday);
300 	tm->tm_mon = bcd2bin(tm->tm_mon) - 1;
301 	/* epoch == 1900 */
302 	tm->tm_year = bcd2bin(tm->tm_year) + 100;
303 }
304 
305 static void omap_rtc_read_time_raw(struct omap_rtc *rtc, struct rtc_time *tm)
306 {
307 	tm->tm_sec = rtc_read(rtc, OMAP_RTC_SECONDS_REG);
308 	tm->tm_min = rtc_read(rtc, OMAP_RTC_MINUTES_REG);
309 	tm->tm_hour = rtc_read(rtc, OMAP_RTC_HOURS_REG);
310 	tm->tm_mday = rtc_read(rtc, OMAP_RTC_DAYS_REG);
311 	tm->tm_mon = rtc_read(rtc, OMAP_RTC_MONTHS_REG);
312 	tm->tm_year = rtc_read(rtc, OMAP_RTC_YEARS_REG);
313 }
314 
315 static int omap_rtc_read_time(struct device *dev, struct rtc_time *tm)
316 {
317 	struct omap_rtc *rtc = dev_get_drvdata(dev);
318 
319 	/* we don't report wday/yday/isdst ... */
320 	local_irq_disable();
321 	rtc_wait_not_busy(rtc);
322 	omap_rtc_read_time_raw(rtc, tm);
323 	local_irq_enable();
324 
325 	bcd2tm(tm);
326 
327 	return 0;
328 }
329 
330 static int omap_rtc_set_time(struct device *dev, struct rtc_time *tm)
331 {
332 	struct omap_rtc *rtc = dev_get_drvdata(dev);
333 
334 	if (tm2bcd(tm) < 0)
335 		return -EINVAL;
336 
337 	local_irq_disable();
338 	rtc_wait_not_busy(rtc);
339 
340 	rtc->type->unlock(rtc);
341 	rtc_write(rtc, OMAP_RTC_YEARS_REG, tm->tm_year);
342 	rtc_write(rtc, OMAP_RTC_MONTHS_REG, tm->tm_mon);
343 	rtc_write(rtc, OMAP_RTC_DAYS_REG, tm->tm_mday);
344 	rtc_write(rtc, OMAP_RTC_HOURS_REG, tm->tm_hour);
345 	rtc_write(rtc, OMAP_RTC_MINUTES_REG, tm->tm_min);
346 	rtc_write(rtc, OMAP_RTC_SECONDS_REG, tm->tm_sec);
347 	rtc->type->lock(rtc);
348 
349 	local_irq_enable();
350 
351 	return 0;
352 }
353 
354 static int omap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
355 {
356 	struct omap_rtc *rtc = dev_get_drvdata(dev);
357 	u8 interrupts;
358 
359 	local_irq_disable();
360 	rtc_wait_not_busy(rtc);
361 
362 	alm->time.tm_sec = rtc_read(rtc, OMAP_RTC_ALARM_SECONDS_REG);
363 	alm->time.tm_min = rtc_read(rtc, OMAP_RTC_ALARM_MINUTES_REG);
364 	alm->time.tm_hour = rtc_read(rtc, OMAP_RTC_ALARM_HOURS_REG);
365 	alm->time.tm_mday = rtc_read(rtc, OMAP_RTC_ALARM_DAYS_REG);
366 	alm->time.tm_mon = rtc_read(rtc, OMAP_RTC_ALARM_MONTHS_REG);
367 	alm->time.tm_year = rtc_read(rtc, OMAP_RTC_ALARM_YEARS_REG);
368 
369 	local_irq_enable();
370 
371 	bcd2tm(&alm->time);
372 
373 	interrupts = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
374 	alm->enabled = !!(interrupts & OMAP_RTC_INTERRUPTS_IT_ALARM);
375 
376 	return 0;
377 }
378 
379 static int omap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
380 {
381 	struct omap_rtc *rtc = dev_get_drvdata(dev);
382 	u8 reg, irqwake_reg = 0;
383 
384 	if (tm2bcd(&alm->time) < 0)
385 		return -EINVAL;
386 
387 	local_irq_disable();
388 	rtc_wait_not_busy(rtc);
389 
390 	rtc->type->unlock(rtc);
391 	rtc_write(rtc, OMAP_RTC_ALARM_YEARS_REG, alm->time.tm_year);
392 	rtc_write(rtc, OMAP_RTC_ALARM_MONTHS_REG, alm->time.tm_mon);
393 	rtc_write(rtc, OMAP_RTC_ALARM_DAYS_REG, alm->time.tm_mday);
394 	rtc_write(rtc, OMAP_RTC_ALARM_HOURS_REG, alm->time.tm_hour);
395 	rtc_write(rtc, OMAP_RTC_ALARM_MINUTES_REG, alm->time.tm_min);
396 	rtc_write(rtc, OMAP_RTC_ALARM_SECONDS_REG, alm->time.tm_sec);
397 
398 	reg = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
399 	if (rtc->type->has_irqwakeen)
400 		irqwake_reg = rtc_read(rtc, OMAP_RTC_IRQWAKEEN);
401 
402 	if (alm->enabled) {
403 		reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
404 		irqwake_reg |= OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
405 	} else {
406 		reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
407 		irqwake_reg &= ~OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
408 	}
409 	rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, reg);
410 	if (rtc->type->has_irqwakeen)
411 		rtc_write(rtc, OMAP_RTC_IRQWAKEEN, irqwake_reg);
412 	rtc->type->lock(rtc);
413 
414 	local_irq_enable();
415 
416 	return 0;
417 }
418 
419 static struct omap_rtc *omap_rtc_power_off_rtc;
420 
421 /*
422  * omap_rtc_poweroff: RTC-controlled power off
423  *
424  * The RTC can be used to control an external PMIC via the pmic_power_en pin,
425  * which can be configured to transition to OFF on ALARM2 events.
426  *
427  * Notes:
428  * The two-second alarm offset is the shortest offset possible as the alarm
429  * registers must be set before the next timer update and the offset
430  * calculation is too heavy for everything to be done within a single access
431  * period (~15 us).
432  *
433  * Called with local interrupts disabled.
434  */
435 static void omap_rtc_power_off(void)
436 {
437 	struct omap_rtc *rtc = omap_rtc_power_off_rtc;
438 	struct rtc_time tm;
439 	unsigned long now;
440 	u32 val;
441 
442 	rtc->type->unlock(rtc);
443 	/* enable pmic_power_en control */
444 	val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
445 	rtc_writel(rtc, OMAP_RTC_PMIC_REG, val | OMAP_RTC_PMIC_POWER_EN_EN);
446 
447 	/* set alarm two seconds from now */
448 	omap_rtc_read_time_raw(rtc, &tm);
449 	bcd2tm(&tm);
450 	rtc_tm_to_time(&tm, &now);
451 	rtc_time_to_tm(now + 2, &tm);
452 
453 	if (tm2bcd(&tm) < 0) {
454 		dev_err(&rtc->rtc->dev, "power off failed\n");
455 		return;
456 	}
457 
458 	rtc_wait_not_busy(rtc);
459 
460 	rtc_write(rtc, OMAP_RTC_ALARM2_SECONDS_REG, tm.tm_sec);
461 	rtc_write(rtc, OMAP_RTC_ALARM2_MINUTES_REG, tm.tm_min);
462 	rtc_write(rtc, OMAP_RTC_ALARM2_HOURS_REG, tm.tm_hour);
463 	rtc_write(rtc, OMAP_RTC_ALARM2_DAYS_REG, tm.tm_mday);
464 	rtc_write(rtc, OMAP_RTC_ALARM2_MONTHS_REG, tm.tm_mon);
465 	rtc_write(rtc, OMAP_RTC_ALARM2_YEARS_REG, tm.tm_year);
466 
467 	/*
468 	 * enable ALARM2 interrupt
469 	 *
470 	 * NOTE: this fails on AM3352 if rtc_write (writeb) is used
471 	 */
472 	val = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
473 	rtc_writel(rtc, OMAP_RTC_INTERRUPTS_REG,
474 			val | OMAP_RTC_INTERRUPTS_IT_ALARM2);
475 	rtc->type->lock(rtc);
476 
477 	/*
478 	 * Wait for alarm to trigger (within two seconds) and external PMIC to
479 	 * power off the system. Add a 500 ms margin for external latencies
480 	 * (e.g. debounce circuits).
481 	 */
482 	mdelay(2500);
483 }
484 
485 static const struct rtc_class_ops omap_rtc_ops = {
486 	.read_time	= omap_rtc_read_time,
487 	.set_time	= omap_rtc_set_time,
488 	.read_alarm	= omap_rtc_read_alarm,
489 	.set_alarm	= omap_rtc_set_alarm,
490 	.alarm_irq_enable = omap_rtc_alarm_irq_enable,
491 };
492 
493 static const struct omap_rtc_device_type omap_rtc_default_type = {
494 	.has_power_up_reset = true,
495 	.lock		= default_rtc_lock,
496 	.unlock		= default_rtc_unlock,
497 };
498 
499 static const struct omap_rtc_device_type omap_rtc_am3352_type = {
500 	.has_32kclk_en	= true,
501 	.has_irqwakeen	= true,
502 	.has_pmic_mode	= true,
503 	.lock		= am3352_rtc_lock,
504 	.unlock		= am3352_rtc_unlock,
505 };
506 
507 static const struct omap_rtc_device_type omap_rtc_da830_type = {
508 	.lock		= am3352_rtc_lock,
509 	.unlock		= am3352_rtc_unlock,
510 };
511 
512 static const struct platform_device_id omap_rtc_id_table[] = {
513 	{
514 		.name	= "omap_rtc",
515 		.driver_data = (kernel_ulong_t)&omap_rtc_default_type,
516 	}, {
517 		.name	= "am3352-rtc",
518 		.driver_data = (kernel_ulong_t)&omap_rtc_am3352_type,
519 	}, {
520 		.name	= "da830-rtc",
521 		.driver_data = (kernel_ulong_t)&omap_rtc_da830_type,
522 	}, {
523 		/* sentinel */
524 	}
525 };
526 MODULE_DEVICE_TABLE(platform, omap_rtc_id_table);
527 
528 static const struct of_device_id omap_rtc_of_match[] = {
529 	{
530 		.compatible	= "ti,am3352-rtc",
531 		.data		= &omap_rtc_am3352_type,
532 	}, {
533 		.compatible	= "ti,da830-rtc",
534 		.data		= &omap_rtc_da830_type,
535 	}, {
536 		/* sentinel */
537 	}
538 };
539 MODULE_DEVICE_TABLE(of, omap_rtc_of_match);
540 
541 static const struct pinctrl_pin_desc rtc_pins_desc[] = {
542 	PINCTRL_PIN(0, "ext_wakeup0"),
543 	PINCTRL_PIN(1, "ext_wakeup1"),
544 	PINCTRL_PIN(2, "ext_wakeup2"),
545 	PINCTRL_PIN(3, "ext_wakeup3"),
546 };
547 
548 static int rtc_pinctrl_get_groups_count(struct pinctrl_dev *pctldev)
549 {
550 	return 0;
551 }
552 
553 static const char *rtc_pinctrl_get_group_name(struct pinctrl_dev *pctldev,
554 					unsigned int group)
555 {
556 	return NULL;
557 }
558 
559 static const struct pinctrl_ops rtc_pinctrl_ops = {
560 	.get_groups_count = rtc_pinctrl_get_groups_count,
561 	.get_group_name = rtc_pinctrl_get_group_name,
562 	.dt_node_to_map = pinconf_generic_dt_node_to_map_pin,
563 	.dt_free_map = pinconf_generic_dt_free_map,
564 };
565 
566 enum rtc_pin_config_param {
567 	PIN_CONFIG_ACTIVE_HIGH = PIN_CONFIG_END + 1,
568 };
569 
570 static const struct pinconf_generic_params rtc_params[] = {
571 	{"ti,active-high", PIN_CONFIG_ACTIVE_HIGH, 0},
572 };
573 
574 #ifdef CONFIG_DEBUG_FS
575 static const struct pin_config_item rtc_conf_items[ARRAY_SIZE(rtc_params)] = {
576 	PCONFDUMP(PIN_CONFIG_ACTIVE_HIGH, "input active high", NULL, false),
577 };
578 #endif
579 
580 static int rtc_pinconf_get(struct pinctrl_dev *pctldev,
581 			unsigned int pin, unsigned long *config)
582 {
583 	struct omap_rtc *rtc = pinctrl_dev_get_drvdata(pctldev);
584 	unsigned int param = pinconf_to_config_param(*config);
585 	u32 val;
586 	u16 arg = 0;
587 
588 	rtc->type->unlock(rtc);
589 	val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
590 	rtc->type->lock(rtc);
591 
592 	switch (param) {
593 	case PIN_CONFIG_INPUT_ENABLE:
594 		if (!(val & OMAP_RTC_PMIC_EXT_WKUP_EN(pin)))
595 			return -EINVAL;
596 		break;
597 	case PIN_CONFIG_ACTIVE_HIGH:
598 		if (val & OMAP_RTC_PMIC_EXT_WKUP_POL(pin))
599 			return -EINVAL;
600 		break;
601 	default:
602 		return -ENOTSUPP;
603 	};
604 
605 	*config = pinconf_to_config_packed(param, arg);
606 
607 	return 0;
608 }
609 
610 static int rtc_pinconf_set(struct pinctrl_dev *pctldev,
611 			unsigned int pin, unsigned long *configs,
612 			unsigned int num_configs)
613 {
614 	struct omap_rtc *rtc = pinctrl_dev_get_drvdata(pctldev);
615 	u32 val;
616 	unsigned int param;
617 	u32 param_val;
618 	int i;
619 
620 	rtc->type->unlock(rtc);
621 	val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
622 	rtc->type->lock(rtc);
623 
624 	/* active low by default */
625 	val |= OMAP_RTC_PMIC_EXT_WKUP_POL(pin);
626 
627 	for (i = 0; i < num_configs; i++) {
628 		param = pinconf_to_config_param(configs[i]);
629 		param_val = pinconf_to_config_argument(configs[i]);
630 
631 		switch (param) {
632 		case PIN_CONFIG_INPUT_ENABLE:
633 			if (param_val)
634 				val |= OMAP_RTC_PMIC_EXT_WKUP_EN(pin);
635 			else
636 				val &= ~OMAP_RTC_PMIC_EXT_WKUP_EN(pin);
637 			break;
638 		case PIN_CONFIG_ACTIVE_HIGH:
639 			val &= ~OMAP_RTC_PMIC_EXT_WKUP_POL(pin);
640 			break;
641 		default:
642 			dev_err(&rtc->rtc->dev, "Property %u not supported\n",
643 				param);
644 			return -ENOTSUPP;
645 		}
646 	}
647 
648 	rtc->type->unlock(rtc);
649 	rtc_writel(rtc, OMAP_RTC_PMIC_REG, val);
650 	rtc->type->lock(rtc);
651 
652 	return 0;
653 }
654 
655 static const struct pinconf_ops rtc_pinconf_ops = {
656 	.is_generic = true,
657 	.pin_config_get = rtc_pinconf_get,
658 	.pin_config_set = rtc_pinconf_set,
659 };
660 
661 static struct pinctrl_desc rtc_pinctrl_desc = {
662 	.pins = rtc_pins_desc,
663 	.npins = ARRAY_SIZE(rtc_pins_desc),
664 	.pctlops = &rtc_pinctrl_ops,
665 	.confops = &rtc_pinconf_ops,
666 	.custom_params = rtc_params,
667 	.num_custom_params = ARRAY_SIZE(rtc_params),
668 #ifdef CONFIG_DEBUG_FS
669 	.custom_conf_items = rtc_conf_items,
670 #endif
671 	.owner = THIS_MODULE,
672 };
673 
674 static int omap_rtc_scratch_read(void *priv, unsigned int offset, void *_val,
675 				 size_t bytes)
676 {
677 	struct omap_rtc	*rtc = priv;
678 	u32 *val = _val;
679 	int i;
680 
681 	for (i = 0; i < bytes / 4; i++)
682 		val[i] = rtc_readl(rtc,
683 				   OMAP_RTC_SCRATCH0_REG + offset + (i * 4));
684 
685 	return 0;
686 }
687 
688 static int omap_rtc_scratch_write(void *priv, unsigned int offset, void *_val,
689 				  size_t bytes)
690 {
691 	struct omap_rtc	*rtc = priv;
692 	u32 *val = _val;
693 	int i;
694 
695 	rtc->type->unlock(rtc);
696 	for (i = 0; i < bytes / 4; i++)
697 		rtc_writel(rtc,
698 			   OMAP_RTC_SCRATCH0_REG + offset + (i * 4), val[i]);
699 	rtc->type->lock(rtc);
700 
701 	return 0;
702 }
703 
704 static struct nvmem_config omap_rtc_nvmem_config = {
705 	.name = "omap_rtc_scratch",
706 	.word_size = 4,
707 	.stride = 4,
708 	.size = OMAP_RTC_KICK0_REG - OMAP_RTC_SCRATCH0_REG,
709 	.reg_read = omap_rtc_scratch_read,
710 	.reg_write = omap_rtc_scratch_write,
711 };
712 
713 static int omap_rtc_probe(struct platform_device *pdev)
714 {
715 	struct omap_rtc	*rtc;
716 	struct resource	*res;
717 	u8 reg, mask, new_ctrl;
718 	const struct platform_device_id *id_entry;
719 	const struct of_device_id *of_id;
720 	int ret;
721 
722 	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
723 	if (!rtc)
724 		return -ENOMEM;
725 
726 	of_id = of_match_device(omap_rtc_of_match, &pdev->dev);
727 	if (of_id) {
728 		rtc->type = of_id->data;
729 		rtc->is_pmic_controller = rtc->type->has_pmic_mode &&
730 				of_property_read_bool(pdev->dev.of_node,
731 						"system-power-controller");
732 	} else {
733 		id_entry = platform_get_device_id(pdev);
734 		rtc->type = (void *)id_entry->driver_data;
735 	}
736 
737 	rtc->irq_timer = platform_get_irq(pdev, 0);
738 	if (rtc->irq_timer <= 0)
739 		return -ENOENT;
740 
741 	rtc->irq_alarm = platform_get_irq(pdev, 1);
742 	if (rtc->irq_alarm <= 0)
743 		return -ENOENT;
744 
745 	rtc->clk = devm_clk_get(&pdev->dev, "ext-clk");
746 	if (!IS_ERR(rtc->clk))
747 		rtc->has_ext_clk = true;
748 	else
749 		rtc->clk = devm_clk_get(&pdev->dev, "int-clk");
750 
751 	if (!IS_ERR(rtc->clk))
752 		clk_prepare_enable(rtc->clk);
753 
754 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
755 	rtc->base = devm_ioremap_resource(&pdev->dev, res);
756 	if (IS_ERR(rtc->base)) {
757 		clk_disable_unprepare(rtc->clk);
758 		return PTR_ERR(rtc->base);
759 	}
760 
761 	platform_set_drvdata(pdev, rtc);
762 
763 	/* Enable the clock/module so that we can access the registers */
764 	pm_runtime_enable(&pdev->dev);
765 	pm_runtime_get_sync(&pdev->dev);
766 
767 	rtc->type->unlock(rtc);
768 
769 	/*
770 	 * disable interrupts
771 	 *
772 	 * NOTE: ALARM2 is not cleared on AM3352 if rtc_write (writeb) is used
773 	 */
774 	rtc_writel(rtc, OMAP_RTC_INTERRUPTS_REG, 0);
775 
776 	/* enable RTC functional clock */
777 	if (rtc->type->has_32kclk_en) {
778 		reg = rtc_read(rtc, OMAP_RTC_OSC_REG);
779 		rtc_writel(rtc, OMAP_RTC_OSC_REG,
780 				reg | OMAP_RTC_OSC_32KCLK_EN);
781 	}
782 
783 	/* clear old status */
784 	reg = rtc_read(rtc, OMAP_RTC_STATUS_REG);
785 
786 	mask = OMAP_RTC_STATUS_ALARM;
787 
788 	if (rtc->type->has_pmic_mode)
789 		mask |= OMAP_RTC_STATUS_ALARM2;
790 
791 	if (rtc->type->has_power_up_reset) {
792 		mask |= OMAP_RTC_STATUS_POWER_UP;
793 		if (reg & OMAP_RTC_STATUS_POWER_UP)
794 			dev_info(&pdev->dev, "RTC power up reset detected\n");
795 	}
796 
797 	if (reg & mask)
798 		rtc_write(rtc, OMAP_RTC_STATUS_REG, reg & mask);
799 
800 	/* On boards with split power, RTC_ON_NOFF won't reset the RTC */
801 	reg = rtc_read(rtc, OMAP_RTC_CTRL_REG);
802 	if (reg & OMAP_RTC_CTRL_STOP)
803 		dev_info(&pdev->dev, "already running\n");
804 
805 	/* force to 24 hour mode */
806 	new_ctrl = reg & (OMAP_RTC_CTRL_SPLIT | OMAP_RTC_CTRL_AUTO_COMP);
807 	new_ctrl |= OMAP_RTC_CTRL_STOP;
808 
809 	/*
810 	 * BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE:
811 	 *
812 	 *  - Device wake-up capability setting should come through chip
813 	 *    init logic. OMAP1 boards should initialize the "wakeup capable"
814 	 *    flag in the platform device if the board is wired right for
815 	 *    being woken up by RTC alarm. For OMAP-L138, this capability
816 	 *    is built into the SoC by the "Deep Sleep" capability.
817 	 *
818 	 *  - Boards wired so RTC_ON_nOFF is used as the reset signal,
819 	 *    rather than nPWRON_RESET, should forcibly enable split
820 	 *    power mode.  (Some chip errata report that RTC_CTRL_SPLIT
821 	 *    is write-only, and always reads as zero...)
822 	 */
823 
824 	if (new_ctrl & OMAP_RTC_CTRL_SPLIT)
825 		dev_info(&pdev->dev, "split power mode\n");
826 
827 	if (reg != new_ctrl)
828 		rtc_write(rtc, OMAP_RTC_CTRL_REG, new_ctrl);
829 
830 	/*
831 	 * If we have the external clock then switch to it so we can keep
832 	 * ticking across suspend.
833 	 */
834 	if (rtc->has_ext_clk) {
835 		reg = rtc_read(rtc, OMAP_RTC_OSC_REG);
836 		reg &= ~OMAP_RTC_OSC_OSC32K_GZ_DISABLE;
837 		reg |= OMAP_RTC_OSC_32KCLK_EN | OMAP_RTC_OSC_SEL_32KCLK_SRC;
838 		rtc_writel(rtc, OMAP_RTC_OSC_REG, reg);
839 	}
840 
841 	rtc->type->lock(rtc);
842 
843 	device_init_wakeup(&pdev->dev, true);
844 
845 	rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
846 	if (IS_ERR(rtc->rtc)) {
847 		ret = PTR_ERR(rtc->rtc);
848 		goto err;
849 	}
850 
851 	rtc->rtc->ops = &omap_rtc_ops;
852 	omap_rtc_nvmem_config.priv = rtc;
853 	rtc->rtc->nvmem_config = &omap_rtc_nvmem_config;
854 
855 	/* handle periodic and alarm irqs */
856 	ret = devm_request_irq(&pdev->dev, rtc->irq_timer, rtc_irq, 0,
857 			dev_name(&rtc->rtc->dev), rtc);
858 	if (ret)
859 		goto err;
860 
861 	if (rtc->irq_timer != rtc->irq_alarm) {
862 		ret = devm_request_irq(&pdev->dev, rtc->irq_alarm, rtc_irq, 0,
863 				dev_name(&rtc->rtc->dev), rtc);
864 		if (ret)
865 			goto err;
866 	}
867 
868 	if (rtc->is_pmic_controller) {
869 		if (!pm_power_off) {
870 			omap_rtc_power_off_rtc = rtc;
871 			pm_power_off = omap_rtc_power_off;
872 		}
873 	}
874 
875 	/* Support ext_wakeup pinconf */
876 	rtc_pinctrl_desc.name = dev_name(&pdev->dev);
877 
878 	rtc->pctldev = pinctrl_register(&rtc_pinctrl_desc, &pdev->dev, rtc);
879 	if (IS_ERR(rtc->pctldev)) {
880 		dev_err(&pdev->dev, "Couldn't register pinctrl driver\n");
881 		ret = PTR_ERR(rtc->pctldev);
882 		goto err;
883 	}
884 
885 	ret = rtc_register_device(rtc->rtc);
886 	if (ret)
887 		goto err;
888 
889 	return 0;
890 
891 err:
892 	clk_disable_unprepare(rtc->clk);
893 	device_init_wakeup(&pdev->dev, false);
894 	rtc->type->lock(rtc);
895 	pm_runtime_put_sync(&pdev->dev);
896 	pm_runtime_disable(&pdev->dev);
897 
898 	return ret;
899 }
900 
901 static int omap_rtc_remove(struct platform_device *pdev)
902 {
903 	struct omap_rtc *rtc = platform_get_drvdata(pdev);
904 	u8 reg;
905 
906 	if (pm_power_off == omap_rtc_power_off &&
907 			omap_rtc_power_off_rtc == rtc) {
908 		pm_power_off = NULL;
909 		omap_rtc_power_off_rtc = NULL;
910 	}
911 
912 	device_init_wakeup(&pdev->dev, 0);
913 
914 	if (!IS_ERR(rtc->clk))
915 		clk_disable_unprepare(rtc->clk);
916 
917 	rtc->type->unlock(rtc);
918 	/* leave rtc running, but disable irqs */
919 	rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, 0);
920 
921 	if (rtc->has_ext_clk) {
922 		reg = rtc_read(rtc, OMAP_RTC_OSC_REG);
923 		reg &= ~OMAP_RTC_OSC_SEL_32KCLK_SRC;
924 		rtc_write(rtc, OMAP_RTC_OSC_REG, reg);
925 	}
926 
927 	rtc->type->lock(rtc);
928 
929 	/* Disable the clock/module */
930 	pm_runtime_put_sync(&pdev->dev);
931 	pm_runtime_disable(&pdev->dev);
932 
933 	/* Remove ext_wakeup pinconf */
934 	pinctrl_unregister(rtc->pctldev);
935 
936 	return 0;
937 }
938 
939 static int __maybe_unused omap_rtc_suspend(struct device *dev)
940 {
941 	struct omap_rtc *rtc = dev_get_drvdata(dev);
942 
943 	rtc->interrupts_reg = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
944 
945 	rtc->type->unlock(rtc);
946 	/*
947 	 * FIXME: the RTC alarm is not currently acting as a wakeup event
948 	 * source on some platforms, and in fact this enable() call is just
949 	 * saving a flag that's never used...
950 	 */
951 	if (device_may_wakeup(dev))
952 		enable_irq_wake(rtc->irq_alarm);
953 	else
954 		rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, 0);
955 	rtc->type->lock(rtc);
956 
957 	rtc->is_suspending = true;
958 
959 	return 0;
960 }
961 
962 static int __maybe_unused omap_rtc_resume(struct device *dev)
963 {
964 	struct omap_rtc *rtc = dev_get_drvdata(dev);
965 
966 	rtc->type->unlock(rtc);
967 	if (device_may_wakeup(dev))
968 		disable_irq_wake(rtc->irq_alarm);
969 	else
970 		rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, rtc->interrupts_reg);
971 	rtc->type->lock(rtc);
972 
973 	rtc->is_suspending = false;
974 
975 	return 0;
976 }
977 
978 static int __maybe_unused omap_rtc_runtime_suspend(struct device *dev)
979 {
980 	struct omap_rtc *rtc = dev_get_drvdata(dev);
981 
982 	if (rtc->is_suspending && !rtc->has_ext_clk)
983 		return -EBUSY;
984 
985 	return 0;
986 }
987 
988 static const struct dev_pm_ops omap_rtc_pm_ops = {
989 	SET_SYSTEM_SLEEP_PM_OPS(omap_rtc_suspend, omap_rtc_resume)
990 	SET_RUNTIME_PM_OPS(omap_rtc_runtime_suspend, NULL, NULL)
991 };
992 
993 static void omap_rtc_shutdown(struct platform_device *pdev)
994 {
995 	struct omap_rtc *rtc = platform_get_drvdata(pdev);
996 	u8 mask;
997 
998 	/*
999 	 * Keep the ALARM interrupt enabled to allow the system to power up on
1000 	 * alarm events.
1001 	 */
1002 	rtc->type->unlock(rtc);
1003 	mask = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
1004 	mask &= OMAP_RTC_INTERRUPTS_IT_ALARM;
1005 	rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, mask);
1006 	rtc->type->lock(rtc);
1007 }
1008 
1009 static struct platform_driver omap_rtc_driver = {
1010 	.probe		= omap_rtc_probe,
1011 	.remove		= omap_rtc_remove,
1012 	.shutdown	= omap_rtc_shutdown,
1013 	.driver		= {
1014 		.name	= "omap_rtc",
1015 		.pm	= &omap_rtc_pm_ops,
1016 		.of_match_table = omap_rtc_of_match,
1017 	},
1018 	.id_table	= omap_rtc_id_table,
1019 };
1020 
1021 module_platform_driver(omap_rtc_driver);
1022 
1023 MODULE_ALIAS("platform:omap_rtc");
1024 MODULE_AUTHOR("George G. Davis (and others)");
1025 MODULE_LICENSE("GPL");
1026