xref: /linux/drivers/rtc/rtc-omap.c (revision 87c9c16317882dd6dbbc07e349bc3223e14f3244)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * TI OMAP Real Time Clock interface for Linux
4  *
5  * Copyright (C) 2003 MontaVista Software, Inc.
6  * Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com>
7  *
8  * Copyright (C) 2006 David Brownell (new RTC framework)
9  * Copyright (C) 2014 Johan Hovold <johan@kernel.org>
10  */
11 
12 #include <linux/bcd.h>
13 #include <linux/clk.h>
14 #include <linux/delay.h>
15 #include <linux/init.h>
16 #include <linux/io.h>
17 #include <linux/ioport.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 #include <linux/of_device.h>
22 #include <linux/pinctrl/pinctrl.h>
23 #include <linux/pinctrl/pinconf.h>
24 #include <linux/pinctrl/pinconf-generic.h>
25 #include <linux/platform_device.h>
26 #include <linux/pm_runtime.h>
27 #include <linux/rtc.h>
28 
29 /*
30  * The OMAP RTC is a year/month/day/hours/minutes/seconds BCD clock
31  * with century-range alarm matching, driven by the 32kHz clock.
32  *
33  * The main user-visible ways it differs from PC RTCs are by omitting
34  * "don't care" alarm fields and sub-second periodic IRQs, and having
35  * an autoadjust mechanism to calibrate to the true oscillator rate.
36  *
37  * Board-specific wiring options include using split power mode with
38  * RTC_OFF_NOFF used as the reset signal (so the RTC won't be reset),
39  * and wiring RTC_WAKE_INT (so the RTC alarm can wake the system from
40  * low power modes) for OMAP1 boards (OMAP-L138 has this built into
41  * the SoC). See the BOARD-SPECIFIC CUSTOMIZATION comment.
42  */
43 
44 /* RTC registers */
45 #define OMAP_RTC_SECONDS_REG		0x00
46 #define OMAP_RTC_MINUTES_REG		0x04
47 #define OMAP_RTC_HOURS_REG		0x08
48 #define OMAP_RTC_DAYS_REG		0x0C
49 #define OMAP_RTC_MONTHS_REG		0x10
50 #define OMAP_RTC_YEARS_REG		0x14
51 #define OMAP_RTC_WEEKS_REG		0x18
52 
53 #define OMAP_RTC_ALARM_SECONDS_REG	0x20
54 #define OMAP_RTC_ALARM_MINUTES_REG	0x24
55 #define OMAP_RTC_ALARM_HOURS_REG	0x28
56 #define OMAP_RTC_ALARM_DAYS_REG		0x2c
57 #define OMAP_RTC_ALARM_MONTHS_REG	0x30
58 #define OMAP_RTC_ALARM_YEARS_REG	0x34
59 
60 #define OMAP_RTC_CTRL_REG		0x40
61 #define OMAP_RTC_STATUS_REG		0x44
62 #define OMAP_RTC_INTERRUPTS_REG		0x48
63 
64 #define OMAP_RTC_COMP_LSB_REG		0x4c
65 #define OMAP_RTC_COMP_MSB_REG		0x50
66 #define OMAP_RTC_OSC_REG		0x54
67 
68 #define OMAP_RTC_SCRATCH0_REG		0x60
69 #define OMAP_RTC_SCRATCH1_REG		0x64
70 #define OMAP_RTC_SCRATCH2_REG		0x68
71 
72 #define OMAP_RTC_KICK0_REG		0x6c
73 #define OMAP_RTC_KICK1_REG		0x70
74 
75 #define OMAP_RTC_IRQWAKEEN		0x7c
76 
77 #define OMAP_RTC_ALARM2_SECONDS_REG	0x80
78 #define OMAP_RTC_ALARM2_MINUTES_REG	0x84
79 #define OMAP_RTC_ALARM2_HOURS_REG	0x88
80 #define OMAP_RTC_ALARM2_DAYS_REG	0x8c
81 #define OMAP_RTC_ALARM2_MONTHS_REG	0x90
82 #define OMAP_RTC_ALARM2_YEARS_REG	0x94
83 
84 #define OMAP_RTC_PMIC_REG		0x98
85 
86 /* OMAP_RTC_CTRL_REG bit fields: */
87 #define OMAP_RTC_CTRL_SPLIT		BIT(7)
88 #define OMAP_RTC_CTRL_DISABLE		BIT(6)
89 #define OMAP_RTC_CTRL_SET_32_COUNTER	BIT(5)
90 #define OMAP_RTC_CTRL_TEST		BIT(4)
91 #define OMAP_RTC_CTRL_MODE_12_24	BIT(3)
92 #define OMAP_RTC_CTRL_AUTO_COMP		BIT(2)
93 #define OMAP_RTC_CTRL_ROUND_30S		BIT(1)
94 #define OMAP_RTC_CTRL_STOP		BIT(0)
95 
96 /* OMAP_RTC_STATUS_REG bit fields: */
97 #define OMAP_RTC_STATUS_POWER_UP	BIT(7)
98 #define OMAP_RTC_STATUS_ALARM2		BIT(7)
99 #define OMAP_RTC_STATUS_ALARM		BIT(6)
100 #define OMAP_RTC_STATUS_1D_EVENT	BIT(5)
101 #define OMAP_RTC_STATUS_1H_EVENT	BIT(4)
102 #define OMAP_RTC_STATUS_1M_EVENT	BIT(3)
103 #define OMAP_RTC_STATUS_1S_EVENT	BIT(2)
104 #define OMAP_RTC_STATUS_RUN		BIT(1)
105 #define OMAP_RTC_STATUS_BUSY		BIT(0)
106 
107 /* OMAP_RTC_INTERRUPTS_REG bit fields: */
108 #define OMAP_RTC_INTERRUPTS_IT_ALARM2	BIT(4)
109 #define OMAP_RTC_INTERRUPTS_IT_ALARM	BIT(3)
110 #define OMAP_RTC_INTERRUPTS_IT_TIMER	BIT(2)
111 
112 /* OMAP_RTC_OSC_REG bit fields: */
113 #define OMAP_RTC_OSC_32KCLK_EN		BIT(6)
114 #define OMAP_RTC_OSC_SEL_32KCLK_SRC	BIT(3)
115 #define OMAP_RTC_OSC_OSC32K_GZ_DISABLE	BIT(4)
116 
117 /* OMAP_RTC_IRQWAKEEN bit fields: */
118 #define OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN	BIT(1)
119 
120 /* OMAP_RTC_PMIC bit fields: */
121 #define OMAP_RTC_PMIC_POWER_EN_EN	BIT(16)
122 #define OMAP_RTC_PMIC_EXT_WKUP_EN(x)	BIT(x)
123 #define OMAP_RTC_PMIC_EXT_WKUP_POL(x)	BIT(4 + x)
124 
125 /* OMAP_RTC_KICKER values */
126 #define	KICK0_VALUE			0x83e70b13
127 #define	KICK1_VALUE			0x95a4f1e0
128 
129 struct omap_rtc;
130 
131 struct omap_rtc_device_type {
132 	bool has_32kclk_en;
133 	bool has_irqwakeen;
134 	bool has_pmic_mode;
135 	bool has_power_up_reset;
136 	void (*lock)(struct omap_rtc *rtc);
137 	void (*unlock)(struct omap_rtc *rtc);
138 };
139 
140 struct omap_rtc {
141 	struct rtc_device *rtc;
142 	void __iomem *base;
143 	struct clk *clk;
144 	int irq_alarm;
145 	int irq_timer;
146 	u8 interrupts_reg;
147 	bool is_pmic_controller;
148 	bool has_ext_clk;
149 	bool is_suspending;
150 	const struct omap_rtc_device_type *type;
151 	struct pinctrl_dev *pctldev;
152 };
153 
154 static inline u8 rtc_read(struct omap_rtc *rtc, unsigned int reg)
155 {
156 	return readb(rtc->base + reg);
157 }
158 
159 static inline u32 rtc_readl(struct omap_rtc *rtc, unsigned int reg)
160 {
161 	return readl(rtc->base + reg);
162 }
163 
164 static inline void rtc_write(struct omap_rtc *rtc, unsigned int reg, u8 val)
165 {
166 	writeb(val, rtc->base + reg);
167 }
168 
169 static inline void rtc_writel(struct omap_rtc *rtc, unsigned int reg, u32 val)
170 {
171 	writel(val, rtc->base + reg);
172 }
173 
174 static void am3352_rtc_unlock(struct omap_rtc *rtc)
175 {
176 	rtc_writel(rtc, OMAP_RTC_KICK0_REG, KICK0_VALUE);
177 	rtc_writel(rtc, OMAP_RTC_KICK1_REG, KICK1_VALUE);
178 }
179 
180 static void am3352_rtc_lock(struct omap_rtc *rtc)
181 {
182 	rtc_writel(rtc, OMAP_RTC_KICK0_REG, 0);
183 	rtc_writel(rtc, OMAP_RTC_KICK1_REG, 0);
184 }
185 
186 static void default_rtc_unlock(struct omap_rtc *rtc)
187 {
188 }
189 
190 static void default_rtc_lock(struct omap_rtc *rtc)
191 {
192 }
193 
194 /*
195  * We rely on the rtc framework to handle locking (rtc->ops_lock),
196  * so the only other requirement is that register accesses which
197  * require BUSY to be clear are made with IRQs locally disabled
198  */
199 static void rtc_wait_not_busy(struct omap_rtc *rtc)
200 {
201 	int count;
202 	u8 status;
203 
204 	/* BUSY may stay active for 1/32768 second (~30 usec) */
205 	for (count = 0; count < 50; count++) {
206 		status = rtc_read(rtc, OMAP_RTC_STATUS_REG);
207 		if (!(status & OMAP_RTC_STATUS_BUSY))
208 			break;
209 		udelay(1);
210 	}
211 	/* now we have ~15 usec to read/write various registers */
212 }
213 
214 static irqreturn_t rtc_irq(int irq, void *dev_id)
215 {
216 	struct omap_rtc	*rtc = dev_id;
217 	unsigned long events = 0;
218 	u8 irq_data;
219 
220 	irq_data = rtc_read(rtc, OMAP_RTC_STATUS_REG);
221 
222 	/* alarm irq? */
223 	if (irq_data & OMAP_RTC_STATUS_ALARM) {
224 		rtc->type->unlock(rtc);
225 		rtc_write(rtc, OMAP_RTC_STATUS_REG, OMAP_RTC_STATUS_ALARM);
226 		rtc->type->lock(rtc);
227 		events |= RTC_IRQF | RTC_AF;
228 	}
229 
230 	/* 1/sec periodic/update irq? */
231 	if (irq_data & OMAP_RTC_STATUS_1S_EVENT)
232 		events |= RTC_IRQF | RTC_UF;
233 
234 	rtc_update_irq(rtc->rtc, 1, events);
235 
236 	return IRQ_HANDLED;
237 }
238 
239 static int omap_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
240 {
241 	struct omap_rtc *rtc = dev_get_drvdata(dev);
242 	u8 reg, irqwake_reg = 0;
243 
244 	local_irq_disable();
245 	rtc_wait_not_busy(rtc);
246 	reg = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
247 	if (rtc->type->has_irqwakeen)
248 		irqwake_reg = rtc_read(rtc, OMAP_RTC_IRQWAKEEN);
249 
250 	if (enabled) {
251 		reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
252 		irqwake_reg |= OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
253 	} else {
254 		reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
255 		irqwake_reg &= ~OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
256 	}
257 	rtc_wait_not_busy(rtc);
258 	rtc->type->unlock(rtc);
259 	rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, reg);
260 	if (rtc->type->has_irqwakeen)
261 		rtc_write(rtc, OMAP_RTC_IRQWAKEEN, irqwake_reg);
262 	rtc->type->lock(rtc);
263 	local_irq_enable();
264 
265 	return 0;
266 }
267 
268 /* this hardware doesn't support "don't care" alarm fields */
269 static void tm2bcd(struct rtc_time *tm)
270 {
271 	tm->tm_sec = bin2bcd(tm->tm_sec);
272 	tm->tm_min = bin2bcd(tm->tm_min);
273 	tm->tm_hour = bin2bcd(tm->tm_hour);
274 	tm->tm_mday = bin2bcd(tm->tm_mday);
275 
276 	tm->tm_mon = bin2bcd(tm->tm_mon + 1);
277 	tm->tm_year = bin2bcd(tm->tm_year - 100);
278 }
279 
280 static void bcd2tm(struct rtc_time *tm)
281 {
282 	tm->tm_sec = bcd2bin(tm->tm_sec);
283 	tm->tm_min = bcd2bin(tm->tm_min);
284 	tm->tm_hour = bcd2bin(tm->tm_hour);
285 	tm->tm_mday = bcd2bin(tm->tm_mday);
286 	tm->tm_mon = bcd2bin(tm->tm_mon) - 1;
287 	/* epoch == 1900 */
288 	tm->tm_year = bcd2bin(tm->tm_year) + 100;
289 }
290 
291 static void omap_rtc_read_time_raw(struct omap_rtc *rtc, struct rtc_time *tm)
292 {
293 	tm->tm_sec = rtc_read(rtc, OMAP_RTC_SECONDS_REG);
294 	tm->tm_min = rtc_read(rtc, OMAP_RTC_MINUTES_REG);
295 	tm->tm_hour = rtc_read(rtc, OMAP_RTC_HOURS_REG);
296 	tm->tm_mday = rtc_read(rtc, OMAP_RTC_DAYS_REG);
297 	tm->tm_mon = rtc_read(rtc, OMAP_RTC_MONTHS_REG);
298 	tm->tm_year = rtc_read(rtc, OMAP_RTC_YEARS_REG);
299 }
300 
301 static int omap_rtc_read_time(struct device *dev, struct rtc_time *tm)
302 {
303 	struct omap_rtc *rtc = dev_get_drvdata(dev);
304 
305 	/* we don't report wday/yday/isdst ... */
306 	local_irq_disable();
307 	rtc_wait_not_busy(rtc);
308 	omap_rtc_read_time_raw(rtc, tm);
309 	local_irq_enable();
310 
311 	bcd2tm(tm);
312 
313 	return 0;
314 }
315 
316 static int omap_rtc_set_time(struct device *dev, struct rtc_time *tm)
317 {
318 	struct omap_rtc *rtc = dev_get_drvdata(dev);
319 
320 	tm2bcd(tm);
321 
322 	local_irq_disable();
323 	rtc_wait_not_busy(rtc);
324 
325 	rtc->type->unlock(rtc);
326 	rtc_write(rtc, OMAP_RTC_YEARS_REG, tm->tm_year);
327 	rtc_write(rtc, OMAP_RTC_MONTHS_REG, tm->tm_mon);
328 	rtc_write(rtc, OMAP_RTC_DAYS_REG, tm->tm_mday);
329 	rtc_write(rtc, OMAP_RTC_HOURS_REG, tm->tm_hour);
330 	rtc_write(rtc, OMAP_RTC_MINUTES_REG, tm->tm_min);
331 	rtc_write(rtc, OMAP_RTC_SECONDS_REG, tm->tm_sec);
332 	rtc->type->lock(rtc);
333 
334 	local_irq_enable();
335 
336 	return 0;
337 }
338 
339 static int omap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
340 {
341 	struct omap_rtc *rtc = dev_get_drvdata(dev);
342 	u8 interrupts;
343 
344 	local_irq_disable();
345 	rtc_wait_not_busy(rtc);
346 
347 	alm->time.tm_sec = rtc_read(rtc, OMAP_RTC_ALARM_SECONDS_REG);
348 	alm->time.tm_min = rtc_read(rtc, OMAP_RTC_ALARM_MINUTES_REG);
349 	alm->time.tm_hour = rtc_read(rtc, OMAP_RTC_ALARM_HOURS_REG);
350 	alm->time.tm_mday = rtc_read(rtc, OMAP_RTC_ALARM_DAYS_REG);
351 	alm->time.tm_mon = rtc_read(rtc, OMAP_RTC_ALARM_MONTHS_REG);
352 	alm->time.tm_year = rtc_read(rtc, OMAP_RTC_ALARM_YEARS_REG);
353 
354 	local_irq_enable();
355 
356 	bcd2tm(&alm->time);
357 
358 	interrupts = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
359 	alm->enabled = !!(interrupts & OMAP_RTC_INTERRUPTS_IT_ALARM);
360 
361 	return 0;
362 }
363 
364 static int omap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
365 {
366 	struct omap_rtc *rtc = dev_get_drvdata(dev);
367 	u8 reg, irqwake_reg = 0;
368 
369 	tm2bcd(&alm->time);
370 
371 	local_irq_disable();
372 	rtc_wait_not_busy(rtc);
373 
374 	rtc->type->unlock(rtc);
375 	rtc_write(rtc, OMAP_RTC_ALARM_YEARS_REG, alm->time.tm_year);
376 	rtc_write(rtc, OMAP_RTC_ALARM_MONTHS_REG, alm->time.tm_mon);
377 	rtc_write(rtc, OMAP_RTC_ALARM_DAYS_REG, alm->time.tm_mday);
378 	rtc_write(rtc, OMAP_RTC_ALARM_HOURS_REG, alm->time.tm_hour);
379 	rtc_write(rtc, OMAP_RTC_ALARM_MINUTES_REG, alm->time.tm_min);
380 	rtc_write(rtc, OMAP_RTC_ALARM_SECONDS_REG, alm->time.tm_sec);
381 
382 	reg = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
383 	if (rtc->type->has_irqwakeen)
384 		irqwake_reg = rtc_read(rtc, OMAP_RTC_IRQWAKEEN);
385 
386 	if (alm->enabled) {
387 		reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
388 		irqwake_reg |= OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
389 	} else {
390 		reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
391 		irqwake_reg &= ~OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
392 	}
393 	rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, reg);
394 	if (rtc->type->has_irqwakeen)
395 		rtc_write(rtc, OMAP_RTC_IRQWAKEEN, irqwake_reg);
396 	rtc->type->lock(rtc);
397 
398 	local_irq_enable();
399 
400 	return 0;
401 }
402 
403 static struct omap_rtc *omap_rtc_power_off_rtc;
404 
405 /**
406  * omap_rtc_power_off_program: Set the pmic power off sequence. The RTC
407  * generates pmic_pwr_enable control, which can be used to control an external
408  * PMIC.
409  */
410 int omap_rtc_power_off_program(struct device *dev)
411 {
412 	struct omap_rtc *rtc = omap_rtc_power_off_rtc;
413 	struct rtc_time tm;
414 	unsigned long now;
415 	int seconds;
416 	u32 val;
417 
418 	rtc->type->unlock(rtc);
419 	/* enable pmic_power_en control */
420 	val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
421 	rtc_writel(rtc, OMAP_RTC_PMIC_REG, val | OMAP_RTC_PMIC_POWER_EN_EN);
422 
423 again:
424 	/* Clear any existing ALARM2 event */
425 	rtc_writel(rtc, OMAP_RTC_STATUS_REG, OMAP_RTC_STATUS_ALARM2);
426 
427 	/* set alarm one second from now */
428 	omap_rtc_read_time_raw(rtc, &tm);
429 	seconds = tm.tm_sec;
430 	bcd2tm(&tm);
431 	now = rtc_tm_to_time64(&tm);
432 	rtc_time64_to_tm(now + 1, &tm);
433 
434 	tm2bcd(&tm);
435 
436 	rtc_wait_not_busy(rtc);
437 
438 	rtc_write(rtc, OMAP_RTC_ALARM2_SECONDS_REG, tm.tm_sec);
439 	rtc_write(rtc, OMAP_RTC_ALARM2_MINUTES_REG, tm.tm_min);
440 	rtc_write(rtc, OMAP_RTC_ALARM2_HOURS_REG, tm.tm_hour);
441 	rtc_write(rtc, OMAP_RTC_ALARM2_DAYS_REG, tm.tm_mday);
442 	rtc_write(rtc, OMAP_RTC_ALARM2_MONTHS_REG, tm.tm_mon);
443 	rtc_write(rtc, OMAP_RTC_ALARM2_YEARS_REG, tm.tm_year);
444 
445 	/*
446 	 * enable ALARM2 interrupt
447 	 *
448 	 * NOTE: this fails on AM3352 if rtc_write (writeb) is used
449 	 */
450 	val = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
451 	rtc_writel(rtc, OMAP_RTC_INTERRUPTS_REG,
452 			val | OMAP_RTC_INTERRUPTS_IT_ALARM2);
453 
454 	/* Retry in case roll over happened before alarm was armed. */
455 	if (rtc_read(rtc, OMAP_RTC_SECONDS_REG) != seconds) {
456 		val = rtc_read(rtc, OMAP_RTC_STATUS_REG);
457 		if (!(val & OMAP_RTC_STATUS_ALARM2))
458 			goto again;
459 	}
460 
461 	rtc->type->lock(rtc);
462 
463 	return 0;
464 }
465 EXPORT_SYMBOL(omap_rtc_power_off_program);
466 
467 /*
468  * omap_rtc_poweroff: RTC-controlled power off
469  *
470  * The RTC can be used to control an external PMIC via the pmic_power_en pin,
471  * which can be configured to transition to OFF on ALARM2 events.
472  *
473  * Notes:
474  * The one-second alarm offset is the shortest offset possible as the alarm
475  * registers must be set before the next timer update and the offset
476  * calculation is too heavy for everything to be done within a single access
477  * period (~15 us).
478  *
479  * Called with local interrupts disabled.
480  */
481 static void omap_rtc_power_off(void)
482 {
483 	struct rtc_device *rtc = omap_rtc_power_off_rtc->rtc;
484 	u32 val;
485 
486 	omap_rtc_power_off_program(rtc->dev.parent);
487 
488 	/* Set PMIC power enable and EXT_WAKEUP in case PB power on is used */
489 	omap_rtc_power_off_rtc->type->unlock(omap_rtc_power_off_rtc);
490 	val = rtc_readl(omap_rtc_power_off_rtc, OMAP_RTC_PMIC_REG);
491 	val |= OMAP_RTC_PMIC_POWER_EN_EN | OMAP_RTC_PMIC_EXT_WKUP_POL(0) |
492 			OMAP_RTC_PMIC_EXT_WKUP_EN(0);
493 	rtc_writel(omap_rtc_power_off_rtc, OMAP_RTC_PMIC_REG, val);
494 	omap_rtc_power_off_rtc->type->lock(omap_rtc_power_off_rtc);
495 
496 	/*
497 	 * Wait for alarm to trigger (within one second) and external PMIC to
498 	 * power off the system. Add a 500 ms margin for external latencies
499 	 * (e.g. debounce circuits).
500 	 */
501 	mdelay(1500);
502 }
503 
504 static const struct rtc_class_ops omap_rtc_ops = {
505 	.read_time	= omap_rtc_read_time,
506 	.set_time	= omap_rtc_set_time,
507 	.read_alarm	= omap_rtc_read_alarm,
508 	.set_alarm	= omap_rtc_set_alarm,
509 	.alarm_irq_enable = omap_rtc_alarm_irq_enable,
510 };
511 
512 static const struct omap_rtc_device_type omap_rtc_default_type = {
513 	.has_power_up_reset = true,
514 	.lock		= default_rtc_lock,
515 	.unlock		= default_rtc_unlock,
516 };
517 
518 static const struct omap_rtc_device_type omap_rtc_am3352_type = {
519 	.has_32kclk_en	= true,
520 	.has_irqwakeen	= true,
521 	.has_pmic_mode	= true,
522 	.lock		= am3352_rtc_lock,
523 	.unlock		= am3352_rtc_unlock,
524 };
525 
526 static const struct omap_rtc_device_type omap_rtc_da830_type = {
527 	.lock		= am3352_rtc_lock,
528 	.unlock		= am3352_rtc_unlock,
529 };
530 
531 static const struct platform_device_id omap_rtc_id_table[] = {
532 	{
533 		.name	= "omap_rtc",
534 		.driver_data = (kernel_ulong_t)&omap_rtc_default_type,
535 	}, {
536 		.name	= "am3352-rtc",
537 		.driver_data = (kernel_ulong_t)&omap_rtc_am3352_type,
538 	}, {
539 		.name	= "da830-rtc",
540 		.driver_data = (kernel_ulong_t)&omap_rtc_da830_type,
541 	}, {
542 		/* sentinel */
543 	}
544 };
545 MODULE_DEVICE_TABLE(platform, omap_rtc_id_table);
546 
547 static const struct of_device_id omap_rtc_of_match[] = {
548 	{
549 		.compatible	= "ti,am3352-rtc",
550 		.data		= &omap_rtc_am3352_type,
551 	}, {
552 		.compatible	= "ti,da830-rtc",
553 		.data		= &omap_rtc_da830_type,
554 	}, {
555 		/* sentinel */
556 	}
557 };
558 MODULE_DEVICE_TABLE(of, omap_rtc_of_match);
559 
560 static const struct pinctrl_pin_desc rtc_pins_desc[] = {
561 	PINCTRL_PIN(0, "ext_wakeup0"),
562 	PINCTRL_PIN(1, "ext_wakeup1"),
563 	PINCTRL_PIN(2, "ext_wakeup2"),
564 	PINCTRL_PIN(3, "ext_wakeup3"),
565 };
566 
567 static int rtc_pinctrl_get_groups_count(struct pinctrl_dev *pctldev)
568 {
569 	return 0;
570 }
571 
572 static const char *rtc_pinctrl_get_group_name(struct pinctrl_dev *pctldev,
573 					unsigned int group)
574 {
575 	return NULL;
576 }
577 
578 static const struct pinctrl_ops rtc_pinctrl_ops = {
579 	.get_groups_count = rtc_pinctrl_get_groups_count,
580 	.get_group_name = rtc_pinctrl_get_group_name,
581 	.dt_node_to_map = pinconf_generic_dt_node_to_map_pin,
582 	.dt_free_map = pinconf_generic_dt_free_map,
583 };
584 
585 #define PIN_CONFIG_ACTIVE_HIGH		(PIN_CONFIG_END + 1)
586 
587 static const struct pinconf_generic_params rtc_params[] = {
588 	{"ti,active-high", PIN_CONFIG_ACTIVE_HIGH, 0},
589 };
590 
591 #ifdef CONFIG_DEBUG_FS
592 static const struct pin_config_item rtc_conf_items[ARRAY_SIZE(rtc_params)] = {
593 	PCONFDUMP(PIN_CONFIG_ACTIVE_HIGH, "input active high", NULL, false),
594 };
595 #endif
596 
597 static int rtc_pinconf_get(struct pinctrl_dev *pctldev,
598 			unsigned int pin, unsigned long *config)
599 {
600 	struct omap_rtc *rtc = pinctrl_dev_get_drvdata(pctldev);
601 	unsigned int param = pinconf_to_config_param(*config);
602 	u32 val;
603 	u16 arg = 0;
604 
605 	val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
606 
607 	switch (param) {
608 	case PIN_CONFIG_INPUT_ENABLE:
609 		if (!(val & OMAP_RTC_PMIC_EXT_WKUP_EN(pin)))
610 			return -EINVAL;
611 		break;
612 	case PIN_CONFIG_ACTIVE_HIGH:
613 		if (val & OMAP_RTC_PMIC_EXT_WKUP_POL(pin))
614 			return -EINVAL;
615 		break;
616 	default:
617 		return -ENOTSUPP;
618 	}
619 
620 	*config = pinconf_to_config_packed(param, arg);
621 
622 	return 0;
623 }
624 
625 static int rtc_pinconf_set(struct pinctrl_dev *pctldev,
626 			unsigned int pin, unsigned long *configs,
627 			unsigned int num_configs)
628 {
629 	struct omap_rtc *rtc = pinctrl_dev_get_drvdata(pctldev);
630 	u32 val;
631 	unsigned int param;
632 	u32 param_val;
633 	int i;
634 
635 	val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
636 
637 	/* active low by default */
638 	val |= OMAP_RTC_PMIC_EXT_WKUP_POL(pin);
639 
640 	for (i = 0; i < num_configs; i++) {
641 		param = pinconf_to_config_param(configs[i]);
642 		param_val = pinconf_to_config_argument(configs[i]);
643 
644 		switch (param) {
645 		case PIN_CONFIG_INPUT_ENABLE:
646 			if (param_val)
647 				val |= OMAP_RTC_PMIC_EXT_WKUP_EN(pin);
648 			else
649 				val &= ~OMAP_RTC_PMIC_EXT_WKUP_EN(pin);
650 			break;
651 		case PIN_CONFIG_ACTIVE_HIGH:
652 			val &= ~OMAP_RTC_PMIC_EXT_WKUP_POL(pin);
653 			break;
654 		default:
655 			dev_err(&rtc->rtc->dev, "Property %u not supported\n",
656 				param);
657 			return -ENOTSUPP;
658 		}
659 	}
660 
661 	rtc->type->unlock(rtc);
662 	rtc_writel(rtc, OMAP_RTC_PMIC_REG, val);
663 	rtc->type->lock(rtc);
664 
665 	return 0;
666 }
667 
668 static const struct pinconf_ops rtc_pinconf_ops = {
669 	.is_generic = true,
670 	.pin_config_get = rtc_pinconf_get,
671 	.pin_config_set = rtc_pinconf_set,
672 };
673 
674 static struct pinctrl_desc rtc_pinctrl_desc = {
675 	.pins = rtc_pins_desc,
676 	.npins = ARRAY_SIZE(rtc_pins_desc),
677 	.pctlops = &rtc_pinctrl_ops,
678 	.confops = &rtc_pinconf_ops,
679 	.custom_params = rtc_params,
680 	.num_custom_params = ARRAY_SIZE(rtc_params),
681 #ifdef CONFIG_DEBUG_FS
682 	.custom_conf_items = rtc_conf_items,
683 #endif
684 	.owner = THIS_MODULE,
685 };
686 
687 static int omap_rtc_scratch_read(void *priv, unsigned int offset, void *_val,
688 				 size_t bytes)
689 {
690 	struct omap_rtc	*rtc = priv;
691 	u32 *val = _val;
692 	int i;
693 
694 	for (i = 0; i < bytes / 4; i++)
695 		val[i] = rtc_readl(rtc,
696 				   OMAP_RTC_SCRATCH0_REG + offset + (i * 4));
697 
698 	return 0;
699 }
700 
701 static int omap_rtc_scratch_write(void *priv, unsigned int offset, void *_val,
702 				  size_t bytes)
703 {
704 	struct omap_rtc	*rtc = priv;
705 	u32 *val = _val;
706 	int i;
707 
708 	rtc->type->unlock(rtc);
709 	for (i = 0; i < bytes / 4; i++)
710 		rtc_writel(rtc,
711 			   OMAP_RTC_SCRATCH0_REG + offset + (i * 4), val[i]);
712 	rtc->type->lock(rtc);
713 
714 	return 0;
715 }
716 
717 static struct nvmem_config omap_rtc_nvmem_config = {
718 	.name = "omap_rtc_scratch",
719 	.word_size = 4,
720 	.stride = 4,
721 	.size = OMAP_RTC_KICK0_REG - OMAP_RTC_SCRATCH0_REG,
722 	.reg_read = omap_rtc_scratch_read,
723 	.reg_write = omap_rtc_scratch_write,
724 };
725 
726 static int omap_rtc_probe(struct platform_device *pdev)
727 {
728 	struct omap_rtc	*rtc;
729 	u8 reg, mask, new_ctrl;
730 	const struct platform_device_id *id_entry;
731 	const struct of_device_id *of_id;
732 	int ret;
733 
734 	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
735 	if (!rtc)
736 		return -ENOMEM;
737 
738 	of_id = of_match_device(omap_rtc_of_match, &pdev->dev);
739 	if (of_id) {
740 		rtc->type = of_id->data;
741 		rtc->is_pmic_controller = rtc->type->has_pmic_mode &&
742 			of_device_is_system_power_controller(pdev->dev.of_node);
743 	} else {
744 		id_entry = platform_get_device_id(pdev);
745 		rtc->type = (void *)id_entry->driver_data;
746 	}
747 
748 	rtc->irq_timer = platform_get_irq(pdev, 0);
749 	if (rtc->irq_timer <= 0)
750 		return -ENOENT;
751 
752 	rtc->irq_alarm = platform_get_irq(pdev, 1);
753 	if (rtc->irq_alarm <= 0)
754 		return -ENOENT;
755 
756 	rtc->clk = devm_clk_get(&pdev->dev, "ext-clk");
757 	if (!IS_ERR(rtc->clk))
758 		rtc->has_ext_clk = true;
759 	else
760 		rtc->clk = devm_clk_get(&pdev->dev, "int-clk");
761 
762 	if (!IS_ERR(rtc->clk))
763 		clk_prepare_enable(rtc->clk);
764 
765 	rtc->base = devm_platform_ioremap_resource(pdev, 0);
766 	if (IS_ERR(rtc->base)) {
767 		clk_disable_unprepare(rtc->clk);
768 		return PTR_ERR(rtc->base);
769 	}
770 
771 	platform_set_drvdata(pdev, rtc);
772 
773 	/* Enable the clock/module so that we can access the registers */
774 	pm_runtime_enable(&pdev->dev);
775 	pm_runtime_get_sync(&pdev->dev);
776 
777 	rtc->type->unlock(rtc);
778 
779 	/*
780 	 * disable interrupts
781 	 *
782 	 * NOTE: ALARM2 is not cleared on AM3352 if rtc_write (writeb) is used
783 	 */
784 	rtc_writel(rtc, OMAP_RTC_INTERRUPTS_REG, 0);
785 
786 	/* enable RTC functional clock */
787 	if (rtc->type->has_32kclk_en) {
788 		reg = rtc_read(rtc, OMAP_RTC_OSC_REG);
789 		rtc_write(rtc, OMAP_RTC_OSC_REG, reg | OMAP_RTC_OSC_32KCLK_EN);
790 	}
791 
792 	/* clear old status */
793 	reg = rtc_read(rtc, OMAP_RTC_STATUS_REG);
794 
795 	mask = OMAP_RTC_STATUS_ALARM;
796 
797 	if (rtc->type->has_pmic_mode)
798 		mask |= OMAP_RTC_STATUS_ALARM2;
799 
800 	if (rtc->type->has_power_up_reset) {
801 		mask |= OMAP_RTC_STATUS_POWER_UP;
802 		if (reg & OMAP_RTC_STATUS_POWER_UP)
803 			dev_info(&pdev->dev, "RTC power up reset detected\n");
804 	}
805 
806 	if (reg & mask)
807 		rtc_write(rtc, OMAP_RTC_STATUS_REG, reg & mask);
808 
809 	/* On boards with split power, RTC_ON_NOFF won't reset the RTC */
810 	reg = rtc_read(rtc, OMAP_RTC_CTRL_REG);
811 	if (reg & OMAP_RTC_CTRL_STOP)
812 		dev_info(&pdev->dev, "already running\n");
813 
814 	/* force to 24 hour mode */
815 	new_ctrl = reg & (OMAP_RTC_CTRL_SPLIT | OMAP_RTC_CTRL_AUTO_COMP);
816 	new_ctrl |= OMAP_RTC_CTRL_STOP;
817 
818 	/*
819 	 * BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE:
820 	 *
821 	 *  - Device wake-up capability setting should come through chip
822 	 *    init logic. OMAP1 boards should initialize the "wakeup capable"
823 	 *    flag in the platform device if the board is wired right for
824 	 *    being woken up by RTC alarm. For OMAP-L138, this capability
825 	 *    is built into the SoC by the "Deep Sleep" capability.
826 	 *
827 	 *  - Boards wired so RTC_ON_nOFF is used as the reset signal,
828 	 *    rather than nPWRON_RESET, should forcibly enable split
829 	 *    power mode.  (Some chip errata report that RTC_CTRL_SPLIT
830 	 *    is write-only, and always reads as zero...)
831 	 */
832 
833 	if (new_ctrl & OMAP_RTC_CTRL_SPLIT)
834 		dev_info(&pdev->dev, "split power mode\n");
835 
836 	if (reg != new_ctrl)
837 		rtc_write(rtc, OMAP_RTC_CTRL_REG, new_ctrl);
838 
839 	/*
840 	 * If we have the external clock then switch to it so we can keep
841 	 * ticking across suspend.
842 	 */
843 	if (rtc->has_ext_clk) {
844 		reg = rtc_read(rtc, OMAP_RTC_OSC_REG);
845 		reg &= ~OMAP_RTC_OSC_OSC32K_GZ_DISABLE;
846 		reg |= OMAP_RTC_OSC_32KCLK_EN | OMAP_RTC_OSC_SEL_32KCLK_SRC;
847 		rtc_write(rtc, OMAP_RTC_OSC_REG, reg);
848 	}
849 
850 	rtc->type->lock(rtc);
851 
852 	device_init_wakeup(&pdev->dev, true);
853 
854 	rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
855 	if (IS_ERR(rtc->rtc)) {
856 		ret = PTR_ERR(rtc->rtc);
857 		goto err;
858 	}
859 
860 	rtc->rtc->ops = &omap_rtc_ops;
861 	rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
862 	rtc->rtc->range_max = RTC_TIMESTAMP_END_2099;
863 	omap_rtc_nvmem_config.priv = rtc;
864 
865 	/* handle periodic and alarm irqs */
866 	ret = devm_request_irq(&pdev->dev, rtc->irq_timer, rtc_irq, 0,
867 			dev_name(&rtc->rtc->dev), rtc);
868 	if (ret)
869 		goto err;
870 
871 	if (rtc->irq_timer != rtc->irq_alarm) {
872 		ret = devm_request_irq(&pdev->dev, rtc->irq_alarm, rtc_irq, 0,
873 				dev_name(&rtc->rtc->dev), rtc);
874 		if (ret)
875 			goto err;
876 	}
877 
878 	/* Support ext_wakeup pinconf */
879 	rtc_pinctrl_desc.name = dev_name(&pdev->dev);
880 
881 	rtc->pctldev = devm_pinctrl_register(&pdev->dev, &rtc_pinctrl_desc, rtc);
882 	if (IS_ERR(rtc->pctldev)) {
883 		dev_err(&pdev->dev, "Couldn't register pinctrl driver\n");
884 		ret = PTR_ERR(rtc->pctldev);
885 		goto err;
886 	}
887 
888 	ret = devm_rtc_register_device(rtc->rtc);
889 	if (ret)
890 		goto err;
891 
892 	devm_rtc_nvmem_register(rtc->rtc, &omap_rtc_nvmem_config);
893 
894 	if (rtc->is_pmic_controller) {
895 		if (!pm_power_off) {
896 			omap_rtc_power_off_rtc = rtc;
897 			pm_power_off = omap_rtc_power_off;
898 		}
899 	}
900 
901 	return 0;
902 
903 err:
904 	clk_disable_unprepare(rtc->clk);
905 	device_init_wakeup(&pdev->dev, false);
906 	rtc->type->lock(rtc);
907 	pm_runtime_put_sync(&pdev->dev);
908 	pm_runtime_disable(&pdev->dev);
909 
910 	return ret;
911 }
912 
913 static int omap_rtc_remove(struct platform_device *pdev)
914 {
915 	struct omap_rtc *rtc = platform_get_drvdata(pdev);
916 	u8 reg;
917 
918 	if (pm_power_off == omap_rtc_power_off &&
919 			omap_rtc_power_off_rtc == rtc) {
920 		pm_power_off = NULL;
921 		omap_rtc_power_off_rtc = NULL;
922 	}
923 
924 	device_init_wakeup(&pdev->dev, 0);
925 
926 	if (!IS_ERR(rtc->clk))
927 		clk_disable_unprepare(rtc->clk);
928 
929 	rtc->type->unlock(rtc);
930 	/* leave rtc running, but disable irqs */
931 	rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, 0);
932 
933 	if (rtc->has_ext_clk) {
934 		reg = rtc_read(rtc, OMAP_RTC_OSC_REG);
935 		reg &= ~OMAP_RTC_OSC_SEL_32KCLK_SRC;
936 		rtc_write(rtc, OMAP_RTC_OSC_REG, reg);
937 	}
938 
939 	rtc->type->lock(rtc);
940 
941 	/* Disable the clock/module */
942 	pm_runtime_put_sync(&pdev->dev);
943 	pm_runtime_disable(&pdev->dev);
944 
945 	return 0;
946 }
947 
948 static int __maybe_unused omap_rtc_suspend(struct device *dev)
949 {
950 	struct omap_rtc *rtc = dev_get_drvdata(dev);
951 
952 	rtc->interrupts_reg = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
953 
954 	rtc->type->unlock(rtc);
955 	/*
956 	 * FIXME: the RTC alarm is not currently acting as a wakeup event
957 	 * source on some platforms, and in fact this enable() call is just
958 	 * saving a flag that's never used...
959 	 */
960 	if (device_may_wakeup(dev))
961 		enable_irq_wake(rtc->irq_alarm);
962 	else
963 		rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, 0);
964 	rtc->type->lock(rtc);
965 
966 	rtc->is_suspending = true;
967 
968 	return 0;
969 }
970 
971 static int __maybe_unused omap_rtc_resume(struct device *dev)
972 {
973 	struct omap_rtc *rtc = dev_get_drvdata(dev);
974 
975 	rtc->type->unlock(rtc);
976 	if (device_may_wakeup(dev))
977 		disable_irq_wake(rtc->irq_alarm);
978 	else
979 		rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, rtc->interrupts_reg);
980 	rtc->type->lock(rtc);
981 
982 	rtc->is_suspending = false;
983 
984 	return 0;
985 }
986 
987 static int __maybe_unused omap_rtc_runtime_suspend(struct device *dev)
988 {
989 	struct omap_rtc *rtc = dev_get_drvdata(dev);
990 
991 	if (rtc->is_suspending && !rtc->has_ext_clk)
992 		return -EBUSY;
993 
994 	return 0;
995 }
996 
997 static const struct dev_pm_ops omap_rtc_pm_ops = {
998 	SET_SYSTEM_SLEEP_PM_OPS(omap_rtc_suspend, omap_rtc_resume)
999 	SET_RUNTIME_PM_OPS(omap_rtc_runtime_suspend, NULL, NULL)
1000 };
1001 
1002 static void omap_rtc_shutdown(struct platform_device *pdev)
1003 {
1004 	struct omap_rtc *rtc = platform_get_drvdata(pdev);
1005 	u8 mask;
1006 
1007 	/*
1008 	 * Keep the ALARM interrupt enabled to allow the system to power up on
1009 	 * alarm events.
1010 	 */
1011 	rtc->type->unlock(rtc);
1012 	mask = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
1013 	mask &= OMAP_RTC_INTERRUPTS_IT_ALARM;
1014 	rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, mask);
1015 	rtc->type->lock(rtc);
1016 }
1017 
1018 static struct platform_driver omap_rtc_driver = {
1019 	.probe		= omap_rtc_probe,
1020 	.remove		= omap_rtc_remove,
1021 	.shutdown	= omap_rtc_shutdown,
1022 	.driver		= {
1023 		.name	= "omap_rtc",
1024 		.pm	= &omap_rtc_pm_ops,
1025 		.of_match_table = omap_rtc_of_match,
1026 	},
1027 	.id_table	= omap_rtc_id_table,
1028 };
1029 
1030 module_platform_driver(omap_rtc_driver);
1031 
1032 MODULE_ALIAS("platform:omap_rtc");
1033 MODULE_AUTHOR("George G. Davis (and others)");
1034 MODULE_LICENSE("GPL");
1035