xref: /openbmc/linux/drivers/rtc/rtc-omap.c (revision 17bfcd6a)
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 #include <linux/rtc/rtc-omap.h>
29 
30 /*
31  * The OMAP RTC is a year/month/day/hours/minutes/seconds BCD clock
32  * with century-range alarm matching, driven by the 32kHz clock.
33  *
34  * The main user-visible ways it differs from PC RTCs are by omitting
35  * "don't care" alarm fields and sub-second periodic IRQs, and having
36  * an autoadjust mechanism to calibrate to the true oscillator rate.
37  *
38  * Board-specific wiring options include using split power mode with
39  * RTC_OFF_NOFF used as the reset signal (so the RTC won't be reset),
40  * and wiring RTC_WAKE_INT (so the RTC alarm can wake the system from
41  * low power modes) for OMAP1 boards (OMAP-L138 has this built into
42  * the SoC). See the BOARD-SPECIFIC CUSTOMIZATION comment.
43  */
44 
45 /* RTC registers */
46 #define OMAP_RTC_SECONDS_REG		0x00
47 #define OMAP_RTC_MINUTES_REG		0x04
48 #define OMAP_RTC_HOURS_REG		0x08
49 #define OMAP_RTC_DAYS_REG		0x0C
50 #define OMAP_RTC_MONTHS_REG		0x10
51 #define OMAP_RTC_YEARS_REG		0x14
52 #define OMAP_RTC_WEEKS_REG		0x18
53 
54 #define OMAP_RTC_ALARM_SECONDS_REG	0x20
55 #define OMAP_RTC_ALARM_MINUTES_REG	0x24
56 #define OMAP_RTC_ALARM_HOURS_REG	0x28
57 #define OMAP_RTC_ALARM_DAYS_REG		0x2c
58 #define OMAP_RTC_ALARM_MONTHS_REG	0x30
59 #define OMAP_RTC_ALARM_YEARS_REG	0x34
60 
61 #define OMAP_RTC_CTRL_REG		0x40
62 #define OMAP_RTC_STATUS_REG		0x44
63 #define OMAP_RTC_INTERRUPTS_REG		0x48
64 
65 #define OMAP_RTC_COMP_LSB_REG		0x4c
66 #define OMAP_RTC_COMP_MSB_REG		0x50
67 #define OMAP_RTC_OSC_REG		0x54
68 
69 #define OMAP_RTC_SCRATCH0_REG		0x60
70 #define OMAP_RTC_SCRATCH1_REG		0x64
71 #define OMAP_RTC_SCRATCH2_REG		0x68
72 
73 #define OMAP_RTC_KICK0_REG		0x6c
74 #define OMAP_RTC_KICK1_REG		0x70
75 
76 #define OMAP_RTC_IRQWAKEEN		0x7c
77 
78 #define OMAP_RTC_ALARM2_SECONDS_REG	0x80
79 #define OMAP_RTC_ALARM2_MINUTES_REG	0x84
80 #define OMAP_RTC_ALARM2_HOURS_REG	0x88
81 #define OMAP_RTC_ALARM2_DAYS_REG	0x8c
82 #define OMAP_RTC_ALARM2_MONTHS_REG	0x90
83 #define OMAP_RTC_ALARM2_YEARS_REG	0x94
84 
85 #define OMAP_RTC_PMIC_REG		0x98
86 
87 /* OMAP_RTC_CTRL_REG bit fields: */
88 #define OMAP_RTC_CTRL_SPLIT		BIT(7)
89 #define OMAP_RTC_CTRL_DISABLE		BIT(6)
90 #define OMAP_RTC_CTRL_SET_32_COUNTER	BIT(5)
91 #define OMAP_RTC_CTRL_TEST		BIT(4)
92 #define OMAP_RTC_CTRL_MODE_12_24	BIT(3)
93 #define OMAP_RTC_CTRL_AUTO_COMP		BIT(2)
94 #define OMAP_RTC_CTRL_ROUND_30S		BIT(1)
95 #define OMAP_RTC_CTRL_STOP		BIT(0)
96 
97 /* OMAP_RTC_STATUS_REG bit fields: */
98 #define OMAP_RTC_STATUS_POWER_UP	BIT(7)
99 #define OMAP_RTC_STATUS_ALARM2		BIT(7)
100 #define OMAP_RTC_STATUS_ALARM		BIT(6)
101 #define OMAP_RTC_STATUS_1D_EVENT	BIT(5)
102 #define OMAP_RTC_STATUS_1H_EVENT	BIT(4)
103 #define OMAP_RTC_STATUS_1M_EVENT	BIT(3)
104 #define OMAP_RTC_STATUS_1S_EVENT	BIT(2)
105 #define OMAP_RTC_STATUS_RUN		BIT(1)
106 #define OMAP_RTC_STATUS_BUSY		BIT(0)
107 
108 /* OMAP_RTC_INTERRUPTS_REG bit fields: */
109 #define OMAP_RTC_INTERRUPTS_IT_ALARM2	BIT(4)
110 #define OMAP_RTC_INTERRUPTS_IT_ALARM	BIT(3)
111 #define OMAP_RTC_INTERRUPTS_IT_TIMER	BIT(2)
112 
113 /* OMAP_RTC_OSC_REG bit fields: */
114 #define OMAP_RTC_OSC_32KCLK_EN		BIT(6)
115 #define OMAP_RTC_OSC_SEL_32KCLK_SRC	BIT(3)
116 #define OMAP_RTC_OSC_OSC32K_GZ_DISABLE	BIT(4)
117 
118 /* OMAP_RTC_IRQWAKEEN bit fields: */
119 #define OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN	BIT(1)
120 
121 /* OMAP_RTC_PMIC bit fields: */
122 #define OMAP_RTC_PMIC_POWER_EN_EN	BIT(16)
123 #define OMAP_RTC_PMIC_EXT_WKUP_EN(x)	BIT(x)
124 #define OMAP_RTC_PMIC_EXT_WKUP_POL(x)	BIT(4 + x)
125 
126 /* OMAP_RTC_KICKER values */
127 #define	KICK0_VALUE			0x83e70b13
128 #define	KICK1_VALUE			0x95a4f1e0
129 
130 struct omap_rtc;
131 
132 struct omap_rtc_device_type {
133 	bool has_32kclk_en;
134 	bool has_irqwakeen;
135 	bool has_pmic_mode;
136 	bool has_power_up_reset;
137 	void (*lock)(struct omap_rtc *rtc);
138 	void (*unlock)(struct omap_rtc *rtc);
139 };
140 
141 struct omap_rtc {
142 	struct rtc_device *rtc;
143 	void __iomem *base;
144 	struct clk *clk;
145 	int irq_alarm;
146 	int irq_timer;
147 	u8 interrupts_reg;
148 	bool is_pmic_controller;
149 	bool has_ext_clk;
150 	bool is_suspending;
151 	const struct omap_rtc_device_type *type;
152 	struct pinctrl_dev *pctldev;
153 };
154 
155 static inline u8 rtc_read(struct omap_rtc *rtc, unsigned int reg)
156 {
157 	return readb(rtc->base + reg);
158 }
159 
160 static inline u32 rtc_readl(struct omap_rtc *rtc, unsigned int reg)
161 {
162 	return readl(rtc->base + reg);
163 }
164 
165 static inline void rtc_write(struct omap_rtc *rtc, unsigned int reg, u8 val)
166 {
167 	writeb(val, rtc->base + reg);
168 }
169 
170 static inline void rtc_writel(struct omap_rtc *rtc, unsigned int reg, u32 val)
171 {
172 	writel(val, rtc->base + reg);
173 }
174 
175 static void am3352_rtc_unlock(struct omap_rtc *rtc)
176 {
177 	rtc_writel(rtc, OMAP_RTC_KICK0_REG, KICK0_VALUE);
178 	rtc_writel(rtc, OMAP_RTC_KICK1_REG, KICK1_VALUE);
179 }
180 
181 static void am3352_rtc_lock(struct omap_rtc *rtc)
182 {
183 	rtc_writel(rtc, OMAP_RTC_KICK0_REG, 0);
184 	rtc_writel(rtc, OMAP_RTC_KICK1_REG, 0);
185 }
186 
187 static void default_rtc_unlock(struct omap_rtc *rtc)
188 {
189 }
190 
191 static void default_rtc_lock(struct omap_rtc *rtc)
192 {
193 }
194 
195 /*
196  * We rely on the rtc framework to handle locking (rtc->ops_lock),
197  * so the only other requirement is that register accesses which
198  * require BUSY to be clear are made with IRQs locally disabled
199  */
200 static void rtc_wait_not_busy(struct omap_rtc *rtc)
201 {
202 	int count;
203 	u8 status;
204 
205 	/* BUSY may stay active for 1/32768 second (~30 usec) */
206 	for (count = 0; count < 50; count++) {
207 		status = rtc_read(rtc, OMAP_RTC_STATUS_REG);
208 		if (!(status & OMAP_RTC_STATUS_BUSY))
209 			break;
210 		udelay(1);
211 	}
212 	/* now we have ~15 usec to read/write various registers */
213 }
214 
215 static irqreturn_t rtc_irq(int irq, void *dev_id)
216 {
217 	struct omap_rtc	*rtc = dev_id;
218 	unsigned long events = 0;
219 	u8 irq_data;
220 
221 	irq_data = rtc_read(rtc, OMAP_RTC_STATUS_REG);
222 
223 	/* alarm irq? */
224 	if (irq_data & OMAP_RTC_STATUS_ALARM) {
225 		rtc->type->unlock(rtc);
226 		rtc_write(rtc, OMAP_RTC_STATUS_REG, OMAP_RTC_STATUS_ALARM);
227 		rtc->type->lock(rtc);
228 		events |= RTC_IRQF | RTC_AF;
229 	}
230 
231 	/* 1/sec periodic/update irq? */
232 	if (irq_data & OMAP_RTC_STATUS_1S_EVENT)
233 		events |= RTC_IRQF | RTC_UF;
234 
235 	rtc_update_irq(rtc->rtc, 1, events);
236 
237 	return IRQ_HANDLED;
238 }
239 
240 static int omap_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
241 {
242 	struct omap_rtc *rtc = dev_get_drvdata(dev);
243 	u8 reg, irqwake_reg = 0;
244 
245 	local_irq_disable();
246 	rtc_wait_not_busy(rtc);
247 	reg = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
248 	if (rtc->type->has_irqwakeen)
249 		irqwake_reg = rtc_read(rtc, OMAP_RTC_IRQWAKEEN);
250 
251 	if (enabled) {
252 		reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
253 		irqwake_reg |= OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
254 	} else {
255 		reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
256 		irqwake_reg &= ~OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
257 	}
258 	rtc_wait_not_busy(rtc);
259 	rtc->type->unlock(rtc);
260 	rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, reg);
261 	if (rtc->type->has_irqwakeen)
262 		rtc_write(rtc, OMAP_RTC_IRQWAKEEN, irqwake_reg);
263 	rtc->type->lock(rtc);
264 	local_irq_enable();
265 
266 	return 0;
267 }
268 
269 /* this hardware doesn't support "don't care" alarm fields */
270 static void tm2bcd(struct rtc_time *tm)
271 {
272 	tm->tm_sec = bin2bcd(tm->tm_sec);
273 	tm->tm_min = bin2bcd(tm->tm_min);
274 	tm->tm_hour = bin2bcd(tm->tm_hour);
275 	tm->tm_mday = bin2bcd(tm->tm_mday);
276 
277 	tm->tm_mon = bin2bcd(tm->tm_mon + 1);
278 	tm->tm_year = bin2bcd(tm->tm_year - 100);
279 }
280 
281 static void bcd2tm(struct rtc_time *tm)
282 {
283 	tm->tm_sec = bcd2bin(tm->tm_sec);
284 	tm->tm_min = bcd2bin(tm->tm_min);
285 	tm->tm_hour = bcd2bin(tm->tm_hour);
286 	tm->tm_mday = bcd2bin(tm->tm_mday);
287 	tm->tm_mon = bcd2bin(tm->tm_mon) - 1;
288 	/* epoch == 1900 */
289 	tm->tm_year = bcd2bin(tm->tm_year) + 100;
290 }
291 
292 static void omap_rtc_read_time_raw(struct omap_rtc *rtc, struct rtc_time *tm)
293 {
294 	tm->tm_sec = rtc_read(rtc, OMAP_RTC_SECONDS_REG);
295 	tm->tm_min = rtc_read(rtc, OMAP_RTC_MINUTES_REG);
296 	tm->tm_hour = rtc_read(rtc, OMAP_RTC_HOURS_REG);
297 	tm->tm_mday = rtc_read(rtc, OMAP_RTC_DAYS_REG);
298 	tm->tm_mon = rtc_read(rtc, OMAP_RTC_MONTHS_REG);
299 	tm->tm_year = rtc_read(rtc, OMAP_RTC_YEARS_REG);
300 }
301 
302 static int omap_rtc_read_time(struct device *dev, struct rtc_time *tm)
303 {
304 	struct omap_rtc *rtc = dev_get_drvdata(dev);
305 
306 	/* we don't report wday/yday/isdst ... */
307 	local_irq_disable();
308 	rtc_wait_not_busy(rtc);
309 	omap_rtc_read_time_raw(rtc, tm);
310 	local_irq_enable();
311 
312 	bcd2tm(tm);
313 
314 	return 0;
315 }
316 
317 static int omap_rtc_set_time(struct device *dev, struct rtc_time *tm)
318 {
319 	struct omap_rtc *rtc = dev_get_drvdata(dev);
320 
321 	tm2bcd(tm);
322 
323 	local_irq_disable();
324 	rtc_wait_not_busy(rtc);
325 
326 	rtc->type->unlock(rtc);
327 	rtc_write(rtc, OMAP_RTC_YEARS_REG, tm->tm_year);
328 	rtc_write(rtc, OMAP_RTC_MONTHS_REG, tm->tm_mon);
329 	rtc_write(rtc, OMAP_RTC_DAYS_REG, tm->tm_mday);
330 	rtc_write(rtc, OMAP_RTC_HOURS_REG, tm->tm_hour);
331 	rtc_write(rtc, OMAP_RTC_MINUTES_REG, tm->tm_min);
332 	rtc_write(rtc, OMAP_RTC_SECONDS_REG, tm->tm_sec);
333 	rtc->type->lock(rtc);
334 
335 	local_irq_enable();
336 
337 	return 0;
338 }
339 
340 static int omap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
341 {
342 	struct omap_rtc *rtc = dev_get_drvdata(dev);
343 	u8 interrupts;
344 
345 	local_irq_disable();
346 	rtc_wait_not_busy(rtc);
347 
348 	alm->time.tm_sec = rtc_read(rtc, OMAP_RTC_ALARM_SECONDS_REG);
349 	alm->time.tm_min = rtc_read(rtc, OMAP_RTC_ALARM_MINUTES_REG);
350 	alm->time.tm_hour = rtc_read(rtc, OMAP_RTC_ALARM_HOURS_REG);
351 	alm->time.tm_mday = rtc_read(rtc, OMAP_RTC_ALARM_DAYS_REG);
352 	alm->time.tm_mon = rtc_read(rtc, OMAP_RTC_ALARM_MONTHS_REG);
353 	alm->time.tm_year = rtc_read(rtc, OMAP_RTC_ALARM_YEARS_REG);
354 
355 	local_irq_enable();
356 
357 	bcd2tm(&alm->time);
358 
359 	interrupts = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
360 	alm->enabled = !!(interrupts & OMAP_RTC_INTERRUPTS_IT_ALARM);
361 
362 	return 0;
363 }
364 
365 static int omap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
366 {
367 	struct omap_rtc *rtc = dev_get_drvdata(dev);
368 	u8 reg, irqwake_reg = 0;
369 
370 	tm2bcd(&alm->time);
371 
372 	local_irq_disable();
373 	rtc_wait_not_busy(rtc);
374 
375 	rtc->type->unlock(rtc);
376 	rtc_write(rtc, OMAP_RTC_ALARM_YEARS_REG, alm->time.tm_year);
377 	rtc_write(rtc, OMAP_RTC_ALARM_MONTHS_REG, alm->time.tm_mon);
378 	rtc_write(rtc, OMAP_RTC_ALARM_DAYS_REG, alm->time.tm_mday);
379 	rtc_write(rtc, OMAP_RTC_ALARM_HOURS_REG, alm->time.tm_hour);
380 	rtc_write(rtc, OMAP_RTC_ALARM_MINUTES_REG, alm->time.tm_min);
381 	rtc_write(rtc, OMAP_RTC_ALARM_SECONDS_REG, alm->time.tm_sec);
382 
383 	reg = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
384 	if (rtc->type->has_irqwakeen)
385 		irqwake_reg = rtc_read(rtc, OMAP_RTC_IRQWAKEEN);
386 
387 	if (alm->enabled) {
388 		reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
389 		irqwake_reg |= OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
390 	} else {
391 		reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
392 		irqwake_reg &= ~OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
393 	}
394 	rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, reg);
395 	if (rtc->type->has_irqwakeen)
396 		rtc_write(rtc, OMAP_RTC_IRQWAKEEN, irqwake_reg);
397 	rtc->type->lock(rtc);
398 
399 	local_irq_enable();
400 
401 	return 0;
402 }
403 
404 static struct omap_rtc *omap_rtc_power_off_rtc;
405 
406 /**
407  * omap_rtc_power_off_program: Set the pmic power off sequence. The RTC
408  * generates pmic_pwr_enable control, which can be used to control an external
409  * PMIC.
410  */
411 int omap_rtc_power_off_program(struct device *dev)
412 {
413 	struct omap_rtc *rtc = omap_rtc_power_off_rtc;
414 	struct rtc_time tm;
415 	unsigned long now;
416 	int seconds;
417 	u32 val;
418 
419 	rtc->type->unlock(rtc);
420 	/* enable pmic_power_en control */
421 	val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
422 	rtc_writel(rtc, OMAP_RTC_PMIC_REG, val | OMAP_RTC_PMIC_POWER_EN_EN);
423 
424 again:
425 	/* Clear any existing ALARM2 event */
426 	rtc_writel(rtc, OMAP_RTC_STATUS_REG, OMAP_RTC_STATUS_ALARM2);
427 
428 	/* set alarm one second from now */
429 	omap_rtc_read_time_raw(rtc, &tm);
430 	seconds = tm.tm_sec;
431 	bcd2tm(&tm);
432 	now = rtc_tm_to_time64(&tm);
433 	rtc_time64_to_tm(now + 1, &tm);
434 
435 	tm2bcd(&tm);
436 
437 	rtc_wait_not_busy(rtc);
438 
439 	rtc_write(rtc, OMAP_RTC_ALARM2_SECONDS_REG, tm.tm_sec);
440 	rtc_write(rtc, OMAP_RTC_ALARM2_MINUTES_REG, tm.tm_min);
441 	rtc_write(rtc, OMAP_RTC_ALARM2_HOURS_REG, tm.tm_hour);
442 	rtc_write(rtc, OMAP_RTC_ALARM2_DAYS_REG, tm.tm_mday);
443 	rtc_write(rtc, OMAP_RTC_ALARM2_MONTHS_REG, tm.tm_mon);
444 	rtc_write(rtc, OMAP_RTC_ALARM2_YEARS_REG, tm.tm_year);
445 
446 	/*
447 	 * enable ALARM2 interrupt
448 	 *
449 	 * NOTE: this fails on AM3352 if rtc_write (writeb) is used
450 	 */
451 	val = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
452 	rtc_writel(rtc, OMAP_RTC_INTERRUPTS_REG,
453 			val | OMAP_RTC_INTERRUPTS_IT_ALARM2);
454 
455 	/* Retry in case roll over happened before alarm was armed. */
456 	if (rtc_read(rtc, OMAP_RTC_SECONDS_REG) != seconds) {
457 		val = rtc_read(rtc, OMAP_RTC_STATUS_REG);
458 		if (!(val & OMAP_RTC_STATUS_ALARM2))
459 			goto again;
460 	}
461 
462 	rtc->type->lock(rtc);
463 
464 	return 0;
465 }
466 EXPORT_SYMBOL(omap_rtc_power_off_program);
467 
468 /*
469  * omap_rtc_poweroff: RTC-controlled power off
470  *
471  * The RTC can be used to control an external PMIC via the pmic_power_en pin,
472  * which can be configured to transition to OFF on ALARM2 events.
473  *
474  * Notes:
475  * The one-second alarm offset is the shortest offset possible as the alarm
476  * registers must be set before the next timer update and the offset
477  * calculation is too heavy for everything to be done within a single access
478  * period (~15 us).
479  *
480  * Called with local interrupts disabled.
481  */
482 static void omap_rtc_power_off(void)
483 {
484 	struct rtc_device *rtc = omap_rtc_power_off_rtc->rtc;
485 	u32 val;
486 
487 	omap_rtc_power_off_program(rtc->dev.parent);
488 
489 	/* Set PMIC power enable and EXT_WAKEUP in case PB power on is used */
490 	omap_rtc_power_off_rtc->type->unlock(omap_rtc_power_off_rtc);
491 	val = rtc_readl(omap_rtc_power_off_rtc, OMAP_RTC_PMIC_REG);
492 	val |= OMAP_RTC_PMIC_POWER_EN_EN | OMAP_RTC_PMIC_EXT_WKUP_POL(0) |
493 			OMAP_RTC_PMIC_EXT_WKUP_EN(0);
494 	rtc_writel(omap_rtc_power_off_rtc, OMAP_RTC_PMIC_REG, val);
495 	omap_rtc_power_off_rtc->type->lock(omap_rtc_power_off_rtc);
496 
497 	/*
498 	 * Wait for alarm to trigger (within one second) and external PMIC to
499 	 * power off the system. Add a 500 ms margin for external latencies
500 	 * (e.g. debounce circuits).
501 	 */
502 	mdelay(1500);
503 }
504 
505 static const struct rtc_class_ops omap_rtc_ops = {
506 	.read_time	= omap_rtc_read_time,
507 	.set_time	= omap_rtc_set_time,
508 	.read_alarm	= omap_rtc_read_alarm,
509 	.set_alarm	= omap_rtc_set_alarm,
510 	.alarm_irq_enable = omap_rtc_alarm_irq_enable,
511 };
512 
513 static const struct omap_rtc_device_type omap_rtc_default_type = {
514 	.has_power_up_reset = true,
515 	.lock		= default_rtc_lock,
516 	.unlock		= default_rtc_unlock,
517 };
518 
519 static const struct omap_rtc_device_type omap_rtc_am3352_type = {
520 	.has_32kclk_en	= true,
521 	.has_irqwakeen	= true,
522 	.has_pmic_mode	= true,
523 	.lock		= am3352_rtc_lock,
524 	.unlock		= am3352_rtc_unlock,
525 };
526 
527 static const struct omap_rtc_device_type omap_rtc_da830_type = {
528 	.lock		= am3352_rtc_lock,
529 	.unlock		= am3352_rtc_unlock,
530 };
531 
532 static const struct platform_device_id omap_rtc_id_table[] = {
533 	{
534 		.name	= "omap_rtc",
535 		.driver_data = (kernel_ulong_t)&omap_rtc_default_type,
536 	}, {
537 		.name	= "am3352-rtc",
538 		.driver_data = (kernel_ulong_t)&omap_rtc_am3352_type,
539 	}, {
540 		.name	= "da830-rtc",
541 		.driver_data = (kernel_ulong_t)&omap_rtc_da830_type,
542 	}, {
543 		/* sentinel */
544 	}
545 };
546 MODULE_DEVICE_TABLE(platform, omap_rtc_id_table);
547 
548 static const struct of_device_id omap_rtc_of_match[] = {
549 	{
550 		.compatible	= "ti,am3352-rtc",
551 		.data		= &omap_rtc_am3352_type,
552 	}, {
553 		.compatible	= "ti,da830-rtc",
554 		.data		= &omap_rtc_da830_type,
555 	}, {
556 		/* sentinel */
557 	}
558 };
559 MODULE_DEVICE_TABLE(of, omap_rtc_of_match);
560 
561 static const struct pinctrl_pin_desc rtc_pins_desc[] = {
562 	PINCTRL_PIN(0, "ext_wakeup0"),
563 	PINCTRL_PIN(1, "ext_wakeup1"),
564 	PINCTRL_PIN(2, "ext_wakeup2"),
565 	PINCTRL_PIN(3, "ext_wakeup3"),
566 };
567 
568 static int rtc_pinctrl_get_groups_count(struct pinctrl_dev *pctldev)
569 {
570 	return 0;
571 }
572 
573 static const char *rtc_pinctrl_get_group_name(struct pinctrl_dev *pctldev,
574 					unsigned int group)
575 {
576 	return NULL;
577 }
578 
579 static const struct pinctrl_ops rtc_pinctrl_ops = {
580 	.get_groups_count = rtc_pinctrl_get_groups_count,
581 	.get_group_name = rtc_pinctrl_get_group_name,
582 	.dt_node_to_map = pinconf_generic_dt_node_to_map_pin,
583 	.dt_free_map = pinconf_generic_dt_free_map,
584 };
585 
586 #define PIN_CONFIG_ACTIVE_HIGH		(PIN_CONFIG_END + 1)
587 
588 static const struct pinconf_generic_params rtc_params[] = {
589 	{"ti,active-high", PIN_CONFIG_ACTIVE_HIGH, 0},
590 };
591 
592 #ifdef CONFIG_DEBUG_FS
593 static const struct pin_config_item rtc_conf_items[ARRAY_SIZE(rtc_params)] = {
594 	PCONFDUMP(PIN_CONFIG_ACTIVE_HIGH, "input active high", NULL, false),
595 };
596 #endif
597 
598 static int rtc_pinconf_get(struct pinctrl_dev *pctldev,
599 			unsigned int pin, unsigned long *config)
600 {
601 	struct omap_rtc *rtc = pinctrl_dev_get_drvdata(pctldev);
602 	unsigned int param = pinconf_to_config_param(*config);
603 	u32 val;
604 	u16 arg = 0;
605 
606 	val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
607 
608 	switch (param) {
609 	case PIN_CONFIG_INPUT_ENABLE:
610 		if (!(val & OMAP_RTC_PMIC_EXT_WKUP_EN(pin)))
611 			return -EINVAL;
612 		break;
613 	case PIN_CONFIG_ACTIVE_HIGH:
614 		if (val & OMAP_RTC_PMIC_EXT_WKUP_POL(pin))
615 			return -EINVAL;
616 		break;
617 	default:
618 		return -ENOTSUPP;
619 	}
620 
621 	*config = pinconf_to_config_packed(param, arg);
622 
623 	return 0;
624 }
625 
626 static int rtc_pinconf_set(struct pinctrl_dev *pctldev,
627 			unsigned int pin, unsigned long *configs,
628 			unsigned int num_configs)
629 {
630 	struct omap_rtc *rtc = pinctrl_dev_get_drvdata(pctldev);
631 	u32 val;
632 	unsigned int param;
633 	u32 param_val;
634 	int i;
635 
636 	val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
637 
638 	/* active low by default */
639 	val |= OMAP_RTC_PMIC_EXT_WKUP_POL(pin);
640 
641 	for (i = 0; i < num_configs; i++) {
642 		param = pinconf_to_config_param(configs[i]);
643 		param_val = pinconf_to_config_argument(configs[i]);
644 
645 		switch (param) {
646 		case PIN_CONFIG_INPUT_ENABLE:
647 			if (param_val)
648 				val |= OMAP_RTC_PMIC_EXT_WKUP_EN(pin);
649 			else
650 				val &= ~OMAP_RTC_PMIC_EXT_WKUP_EN(pin);
651 			break;
652 		case PIN_CONFIG_ACTIVE_HIGH:
653 			val &= ~OMAP_RTC_PMIC_EXT_WKUP_POL(pin);
654 			break;
655 		default:
656 			dev_err(&rtc->rtc->dev, "Property %u not supported\n",
657 				param);
658 			return -ENOTSUPP;
659 		}
660 	}
661 
662 	rtc->type->unlock(rtc);
663 	rtc_writel(rtc, OMAP_RTC_PMIC_REG, val);
664 	rtc->type->lock(rtc);
665 
666 	return 0;
667 }
668 
669 static const struct pinconf_ops rtc_pinconf_ops = {
670 	.is_generic = true,
671 	.pin_config_get = rtc_pinconf_get,
672 	.pin_config_set = rtc_pinconf_set,
673 };
674 
675 static struct pinctrl_desc rtc_pinctrl_desc = {
676 	.pins = rtc_pins_desc,
677 	.npins = ARRAY_SIZE(rtc_pins_desc),
678 	.pctlops = &rtc_pinctrl_ops,
679 	.confops = &rtc_pinconf_ops,
680 	.custom_params = rtc_params,
681 	.num_custom_params = ARRAY_SIZE(rtc_params),
682 #ifdef CONFIG_DEBUG_FS
683 	.custom_conf_items = rtc_conf_items,
684 #endif
685 	.owner = THIS_MODULE,
686 };
687 
688 static int omap_rtc_scratch_read(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 	for (i = 0; i < bytes / 4; i++)
696 		val[i] = rtc_readl(rtc,
697 				   OMAP_RTC_SCRATCH0_REG + offset + (i * 4));
698 
699 	return 0;
700 }
701 
702 static int omap_rtc_scratch_write(void *priv, unsigned int offset, void *_val,
703 				  size_t bytes)
704 {
705 	struct omap_rtc	*rtc = priv;
706 	u32 *val = _val;
707 	int i;
708 
709 	rtc->type->unlock(rtc);
710 	for (i = 0; i < bytes / 4; i++)
711 		rtc_writel(rtc,
712 			   OMAP_RTC_SCRATCH0_REG + offset + (i * 4), val[i]);
713 	rtc->type->lock(rtc);
714 
715 	return 0;
716 }
717 
718 static struct nvmem_config omap_rtc_nvmem_config = {
719 	.name = "omap_rtc_scratch",
720 	.word_size = 4,
721 	.stride = 4,
722 	.size = OMAP_RTC_KICK0_REG - OMAP_RTC_SCRATCH0_REG,
723 	.reg_read = omap_rtc_scratch_read,
724 	.reg_write = omap_rtc_scratch_write,
725 };
726 
727 static int omap_rtc_probe(struct platform_device *pdev)
728 {
729 	struct omap_rtc	*rtc;
730 	u8 reg, mask, new_ctrl;
731 	const struct platform_device_id *id_entry;
732 	const struct of_device_id *of_id;
733 	int ret;
734 
735 	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
736 	if (!rtc)
737 		return -ENOMEM;
738 
739 	of_id = of_match_device(omap_rtc_of_match, &pdev->dev);
740 	if (of_id) {
741 		rtc->type = of_id->data;
742 		rtc->is_pmic_controller = rtc->type->has_pmic_mode &&
743 			of_device_is_system_power_controller(pdev->dev.of_node);
744 	} else {
745 		id_entry = platform_get_device_id(pdev);
746 		rtc->type = (void *)id_entry->driver_data;
747 	}
748 
749 	rtc->irq_timer = platform_get_irq(pdev, 0);
750 	if (rtc->irq_timer < 0)
751 		return rtc->irq_timer;
752 
753 	rtc->irq_alarm = platform_get_irq(pdev, 1);
754 	if (rtc->irq_alarm < 0)
755 		return rtc->irq_alarm;
756 
757 	rtc->clk = devm_clk_get(&pdev->dev, "ext-clk");
758 	if (!IS_ERR(rtc->clk))
759 		rtc->has_ext_clk = true;
760 	else
761 		rtc->clk = devm_clk_get(&pdev->dev, "int-clk");
762 
763 	if (!IS_ERR(rtc->clk))
764 		clk_prepare_enable(rtc->clk);
765 
766 	rtc->base = devm_platform_ioremap_resource(pdev, 0);
767 	if (IS_ERR(rtc->base)) {
768 		clk_disable_unprepare(rtc->clk);
769 		return PTR_ERR(rtc->base);
770 	}
771 
772 	platform_set_drvdata(pdev, rtc);
773 
774 	/* Enable the clock/module so that we can access the registers */
775 	pm_runtime_enable(&pdev->dev);
776 	pm_runtime_get_sync(&pdev->dev);
777 
778 	rtc->type->unlock(rtc);
779 
780 	/*
781 	 * disable interrupts
782 	 *
783 	 * NOTE: ALARM2 is not cleared on AM3352 if rtc_write (writeb) is used
784 	 */
785 	rtc_writel(rtc, OMAP_RTC_INTERRUPTS_REG, 0);
786 
787 	/* enable RTC functional clock */
788 	if (rtc->type->has_32kclk_en) {
789 		reg = rtc_read(rtc, OMAP_RTC_OSC_REG);
790 		rtc_write(rtc, OMAP_RTC_OSC_REG, reg | OMAP_RTC_OSC_32KCLK_EN);
791 	}
792 
793 	/* clear old status */
794 	reg = rtc_read(rtc, OMAP_RTC_STATUS_REG);
795 
796 	mask = OMAP_RTC_STATUS_ALARM;
797 
798 	if (rtc->type->has_pmic_mode)
799 		mask |= OMAP_RTC_STATUS_ALARM2;
800 
801 	if (rtc->type->has_power_up_reset) {
802 		mask |= OMAP_RTC_STATUS_POWER_UP;
803 		if (reg & OMAP_RTC_STATUS_POWER_UP)
804 			dev_info(&pdev->dev, "RTC power up reset detected\n");
805 	}
806 
807 	if (reg & mask)
808 		rtc_write(rtc, OMAP_RTC_STATUS_REG, reg & mask);
809 
810 	/* On boards with split power, RTC_ON_NOFF won't reset the RTC */
811 	reg = rtc_read(rtc, OMAP_RTC_CTRL_REG);
812 	if (reg & OMAP_RTC_CTRL_STOP)
813 		dev_info(&pdev->dev, "already running\n");
814 
815 	/* force to 24 hour mode */
816 	new_ctrl = reg & (OMAP_RTC_CTRL_SPLIT | OMAP_RTC_CTRL_AUTO_COMP);
817 	new_ctrl |= OMAP_RTC_CTRL_STOP;
818 
819 	/*
820 	 * BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE:
821 	 *
822 	 *  - Device wake-up capability setting should come through chip
823 	 *    init logic. OMAP1 boards should initialize the "wakeup capable"
824 	 *    flag in the platform device if the board is wired right for
825 	 *    being woken up by RTC alarm. For OMAP-L138, this capability
826 	 *    is built into the SoC by the "Deep Sleep" capability.
827 	 *
828 	 *  - Boards wired so RTC_ON_nOFF is used as the reset signal,
829 	 *    rather than nPWRON_RESET, should forcibly enable split
830 	 *    power mode.  (Some chip errata report that RTC_CTRL_SPLIT
831 	 *    is write-only, and always reads as zero...)
832 	 */
833 
834 	if (new_ctrl & OMAP_RTC_CTRL_SPLIT)
835 		dev_info(&pdev->dev, "split power mode\n");
836 
837 	if (reg != new_ctrl)
838 		rtc_write(rtc, OMAP_RTC_CTRL_REG, new_ctrl);
839 
840 	/*
841 	 * If we have the external clock then switch to it so we can keep
842 	 * ticking across suspend.
843 	 */
844 	if (rtc->has_ext_clk) {
845 		reg = rtc_read(rtc, OMAP_RTC_OSC_REG);
846 		reg &= ~OMAP_RTC_OSC_OSC32K_GZ_DISABLE;
847 		reg |= OMAP_RTC_OSC_32KCLK_EN | OMAP_RTC_OSC_SEL_32KCLK_SRC;
848 		rtc_write(rtc, OMAP_RTC_OSC_REG, reg);
849 	}
850 
851 	rtc->type->lock(rtc);
852 
853 	device_init_wakeup(&pdev->dev, true);
854 
855 	rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
856 	if (IS_ERR(rtc->rtc)) {
857 		ret = PTR_ERR(rtc->rtc);
858 		goto err;
859 	}
860 
861 	rtc->rtc->ops = &omap_rtc_ops;
862 	rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
863 	rtc->rtc->range_max = RTC_TIMESTAMP_END_2099;
864 	omap_rtc_nvmem_config.priv = rtc;
865 
866 	/* handle periodic and alarm irqs */
867 	ret = devm_request_irq(&pdev->dev, rtc->irq_timer, rtc_irq, 0,
868 			dev_name(&rtc->rtc->dev), rtc);
869 	if (ret)
870 		goto err;
871 
872 	if (rtc->irq_timer != rtc->irq_alarm) {
873 		ret = devm_request_irq(&pdev->dev, rtc->irq_alarm, rtc_irq, 0,
874 				dev_name(&rtc->rtc->dev), rtc);
875 		if (ret)
876 			goto err;
877 	}
878 
879 	/* Support ext_wakeup pinconf */
880 	rtc_pinctrl_desc.name = dev_name(&pdev->dev);
881 
882 	rtc->pctldev = devm_pinctrl_register(&pdev->dev, &rtc_pinctrl_desc, rtc);
883 	if (IS_ERR(rtc->pctldev)) {
884 		dev_err(&pdev->dev, "Couldn't register pinctrl driver\n");
885 		ret = PTR_ERR(rtc->pctldev);
886 		goto err;
887 	}
888 
889 	ret = devm_rtc_register_device(rtc->rtc);
890 	if (ret)
891 		goto err;
892 
893 	devm_rtc_nvmem_register(rtc->rtc, &omap_rtc_nvmem_config);
894 
895 	if (rtc->is_pmic_controller) {
896 		if (!pm_power_off) {
897 			omap_rtc_power_off_rtc = rtc;
898 			pm_power_off = omap_rtc_power_off;
899 		}
900 	}
901 
902 	return 0;
903 
904 err:
905 	clk_disable_unprepare(rtc->clk);
906 	device_init_wakeup(&pdev->dev, false);
907 	rtc->type->lock(rtc);
908 	pm_runtime_put_sync(&pdev->dev);
909 	pm_runtime_disable(&pdev->dev);
910 
911 	return ret;
912 }
913 
914 static void omap_rtc_remove(struct platform_device *pdev)
915 {
916 	struct omap_rtc *rtc = platform_get_drvdata(pdev);
917 	u8 reg;
918 
919 	if (pm_power_off == omap_rtc_power_off &&
920 			omap_rtc_power_off_rtc == rtc) {
921 		pm_power_off = NULL;
922 		omap_rtc_power_off_rtc = NULL;
923 	}
924 
925 	device_init_wakeup(&pdev->dev, 0);
926 
927 	if (!IS_ERR(rtc->clk))
928 		clk_disable_unprepare(rtc->clk);
929 
930 	rtc->type->unlock(rtc);
931 	/* leave rtc running, but disable irqs */
932 	rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, 0);
933 
934 	if (rtc->has_ext_clk) {
935 		reg = rtc_read(rtc, OMAP_RTC_OSC_REG);
936 		reg &= ~OMAP_RTC_OSC_SEL_32KCLK_SRC;
937 		rtc_write(rtc, OMAP_RTC_OSC_REG, reg);
938 	}
939 
940 	rtc->type->lock(rtc);
941 
942 	/* Disable the clock/module */
943 	pm_runtime_put_sync(&pdev->dev);
944 	pm_runtime_disable(&pdev->dev);
945 }
946 
947 static int __maybe_unused omap_rtc_suspend(struct device *dev)
948 {
949 	struct omap_rtc *rtc = dev_get_drvdata(dev);
950 
951 	rtc->interrupts_reg = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
952 
953 	rtc->type->unlock(rtc);
954 	/*
955 	 * FIXME: the RTC alarm is not currently acting as a wakeup event
956 	 * source on some platforms, and in fact this enable() call is just
957 	 * saving a flag that's never used...
958 	 */
959 	if (device_may_wakeup(dev))
960 		enable_irq_wake(rtc->irq_alarm);
961 	else
962 		rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, 0);
963 	rtc->type->lock(rtc);
964 
965 	rtc->is_suspending = true;
966 
967 	return 0;
968 }
969 
970 static int __maybe_unused omap_rtc_resume(struct device *dev)
971 {
972 	struct omap_rtc *rtc = dev_get_drvdata(dev);
973 
974 	rtc->type->unlock(rtc);
975 	if (device_may_wakeup(dev))
976 		disable_irq_wake(rtc->irq_alarm);
977 	else
978 		rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, rtc->interrupts_reg);
979 	rtc->type->lock(rtc);
980 
981 	rtc->is_suspending = false;
982 
983 	return 0;
984 }
985 
986 static int __maybe_unused omap_rtc_runtime_suspend(struct device *dev)
987 {
988 	struct omap_rtc *rtc = dev_get_drvdata(dev);
989 
990 	if (rtc->is_suspending && !rtc->has_ext_clk)
991 		return -EBUSY;
992 
993 	return 0;
994 }
995 
996 static const struct dev_pm_ops omap_rtc_pm_ops = {
997 	SET_SYSTEM_SLEEP_PM_OPS(omap_rtc_suspend, omap_rtc_resume)
998 	SET_RUNTIME_PM_OPS(omap_rtc_runtime_suspend, NULL, NULL)
999 };
1000 
1001 static void omap_rtc_shutdown(struct platform_device *pdev)
1002 {
1003 	struct omap_rtc *rtc = platform_get_drvdata(pdev);
1004 	u8 mask;
1005 
1006 	/*
1007 	 * Keep the ALARM interrupt enabled to allow the system to power up on
1008 	 * alarm events.
1009 	 */
1010 	rtc->type->unlock(rtc);
1011 	mask = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
1012 	mask &= OMAP_RTC_INTERRUPTS_IT_ALARM;
1013 	rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, mask);
1014 	rtc->type->lock(rtc);
1015 }
1016 
1017 static struct platform_driver omap_rtc_driver = {
1018 	.probe		= omap_rtc_probe,
1019 	.remove_new	= omap_rtc_remove,
1020 	.shutdown	= omap_rtc_shutdown,
1021 	.driver		= {
1022 		.name	= "omap_rtc",
1023 		.pm	= &omap_rtc_pm_ops,
1024 		.of_match_table = omap_rtc_of_match,
1025 	},
1026 	.id_table	= omap_rtc_id_table,
1027 };
1028 
1029 module_platform_driver(omap_rtc_driver);
1030 
1031 MODULE_AUTHOR("George G. Davis (and others)");
1032 MODULE_LICENSE("GPL");
1033