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 
rtc_read(struct omap_rtc * rtc,unsigned int reg)159 static inline u8 rtc_read(struct omap_rtc *rtc, unsigned int reg)
160 {
161 	return readb(rtc->base + reg);
162 }
163 
rtc_readl(struct omap_rtc * rtc,unsigned int reg)164 static inline u32 rtc_readl(struct omap_rtc *rtc, unsigned int reg)
165 {
166 	return readl(rtc->base + reg);
167 }
168 
rtc_write(struct omap_rtc * rtc,unsigned int reg,u8 val)169 static inline void rtc_write(struct omap_rtc *rtc, unsigned int reg, u8 val)
170 {
171 	writeb(val, rtc->base + reg);
172 }
173 
rtc_writel(struct omap_rtc * rtc,unsigned int reg,u32 val)174 static inline void rtc_writel(struct omap_rtc *rtc, unsigned int reg, u32 val)
175 {
176 	writel(val, rtc->base + reg);
177 }
178 
am3352_rtc_unlock(struct omap_rtc * rtc)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 
am3352_rtc_lock(struct omap_rtc * rtc)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 
default_rtc_unlock(struct omap_rtc * rtc)191 static void default_rtc_unlock(struct omap_rtc *rtc)
192 {
193 }
194 
default_rtc_lock(struct omap_rtc * rtc)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  */
rtc_wait_not_busy(struct omap_rtc * rtc)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 
rtc_irq(int irq,void * dev_id)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 
omap_rtc_alarm_irq_enable(struct device * dev,unsigned int enabled)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 */
tm2bcd(struct rtc_time * tm)274 static int tm2bcd(struct rtc_time *tm)
275 {
276 	tm->tm_sec = bin2bcd(tm->tm_sec);
277 	tm->tm_min = bin2bcd(tm->tm_min);
278 	tm->tm_hour = bin2bcd(tm->tm_hour);
279 	tm->tm_mday = bin2bcd(tm->tm_mday);
280 
281 	tm->tm_mon = bin2bcd(tm->tm_mon + 1);
282 
283 	/* epoch == 1900 */
284 	if (tm->tm_year < 100 || tm->tm_year > 199)
285 		return -EINVAL;
286 	tm->tm_year = bin2bcd(tm->tm_year - 100);
287 
288 	return 0;
289 }
290 
bcd2tm(struct rtc_time * tm)291 static void bcd2tm(struct rtc_time *tm)
292 {
293 	tm->tm_sec = bcd2bin(tm->tm_sec);
294 	tm->tm_min = bcd2bin(tm->tm_min);
295 	tm->tm_hour = bcd2bin(tm->tm_hour);
296 	tm->tm_mday = bcd2bin(tm->tm_mday);
297 	tm->tm_mon = bcd2bin(tm->tm_mon) - 1;
298 	/* epoch == 1900 */
299 	tm->tm_year = bcd2bin(tm->tm_year) + 100;
300 }
301 
omap_rtc_read_time_raw(struct omap_rtc * rtc,struct rtc_time * tm)302 static void omap_rtc_read_time_raw(struct omap_rtc *rtc, struct rtc_time *tm)
303 {
304 	tm->tm_sec = rtc_read(rtc, OMAP_RTC_SECONDS_REG);
305 	tm->tm_min = rtc_read(rtc, OMAP_RTC_MINUTES_REG);
306 	tm->tm_hour = rtc_read(rtc, OMAP_RTC_HOURS_REG);
307 	tm->tm_mday = rtc_read(rtc, OMAP_RTC_DAYS_REG);
308 	tm->tm_mon = rtc_read(rtc, OMAP_RTC_MONTHS_REG);
309 	tm->tm_year = rtc_read(rtc, OMAP_RTC_YEARS_REG);
310 }
311 
omap_rtc_read_time(struct device * dev,struct rtc_time * tm)312 static int omap_rtc_read_time(struct device *dev, struct rtc_time *tm)
313 {
314 	struct omap_rtc *rtc = dev_get_drvdata(dev);
315 
316 	/* we don't report wday/yday/isdst ... */
317 	local_irq_disable();
318 	rtc_wait_not_busy(rtc);
319 	omap_rtc_read_time_raw(rtc, tm);
320 	local_irq_enable();
321 
322 	bcd2tm(tm);
323 
324 	return 0;
325 }
326 
omap_rtc_set_time(struct device * dev,struct rtc_time * tm)327 static int omap_rtc_set_time(struct device *dev, struct rtc_time *tm)
328 {
329 	struct omap_rtc *rtc = dev_get_drvdata(dev);
330 
331 	if (tm2bcd(tm) < 0)
332 		return -EINVAL;
333 
334 	local_irq_disable();
335 	rtc_wait_not_busy(rtc);
336 
337 	rtc->type->unlock(rtc);
338 	rtc_write(rtc, OMAP_RTC_YEARS_REG, tm->tm_year);
339 	rtc_write(rtc, OMAP_RTC_MONTHS_REG, tm->tm_mon);
340 	rtc_write(rtc, OMAP_RTC_DAYS_REG, tm->tm_mday);
341 	rtc_write(rtc, OMAP_RTC_HOURS_REG, tm->tm_hour);
342 	rtc_write(rtc, OMAP_RTC_MINUTES_REG, tm->tm_min);
343 	rtc_write(rtc, OMAP_RTC_SECONDS_REG, tm->tm_sec);
344 	rtc->type->lock(rtc);
345 
346 	local_irq_enable();
347 
348 	return 0;
349 }
350 
omap_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alm)351 static int omap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
352 {
353 	struct omap_rtc *rtc = dev_get_drvdata(dev);
354 	u8 interrupts;
355 
356 	local_irq_disable();
357 	rtc_wait_not_busy(rtc);
358 
359 	alm->time.tm_sec = rtc_read(rtc, OMAP_RTC_ALARM_SECONDS_REG);
360 	alm->time.tm_min = rtc_read(rtc, OMAP_RTC_ALARM_MINUTES_REG);
361 	alm->time.tm_hour = rtc_read(rtc, OMAP_RTC_ALARM_HOURS_REG);
362 	alm->time.tm_mday = rtc_read(rtc, OMAP_RTC_ALARM_DAYS_REG);
363 	alm->time.tm_mon = rtc_read(rtc, OMAP_RTC_ALARM_MONTHS_REG);
364 	alm->time.tm_year = rtc_read(rtc, OMAP_RTC_ALARM_YEARS_REG);
365 
366 	local_irq_enable();
367 
368 	bcd2tm(&alm->time);
369 
370 	interrupts = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
371 	alm->enabled = !!(interrupts & OMAP_RTC_INTERRUPTS_IT_ALARM);
372 
373 	return 0;
374 }
375 
omap_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alm)376 static int omap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
377 {
378 	struct omap_rtc *rtc = dev_get_drvdata(dev);
379 	u8 reg, irqwake_reg = 0;
380 
381 	if (tm2bcd(&alm->time) < 0)
382 		return -EINVAL;
383 
384 	local_irq_disable();
385 	rtc_wait_not_busy(rtc);
386 
387 	rtc->type->unlock(rtc);
388 	rtc_write(rtc, OMAP_RTC_ALARM_YEARS_REG, alm->time.tm_year);
389 	rtc_write(rtc, OMAP_RTC_ALARM_MONTHS_REG, alm->time.tm_mon);
390 	rtc_write(rtc, OMAP_RTC_ALARM_DAYS_REG, alm->time.tm_mday);
391 	rtc_write(rtc, OMAP_RTC_ALARM_HOURS_REG, alm->time.tm_hour);
392 	rtc_write(rtc, OMAP_RTC_ALARM_MINUTES_REG, alm->time.tm_min);
393 	rtc_write(rtc, OMAP_RTC_ALARM_SECONDS_REG, alm->time.tm_sec);
394 
395 	reg = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
396 	if (rtc->type->has_irqwakeen)
397 		irqwake_reg = rtc_read(rtc, OMAP_RTC_IRQWAKEEN);
398 
399 	if (alm->enabled) {
400 		reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
401 		irqwake_reg |= OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
402 	} else {
403 		reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
404 		irqwake_reg &= ~OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
405 	}
406 	rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, reg);
407 	if (rtc->type->has_irqwakeen)
408 		rtc_write(rtc, OMAP_RTC_IRQWAKEEN, irqwake_reg);
409 	rtc->type->lock(rtc);
410 
411 	local_irq_enable();
412 
413 	return 0;
414 }
415 
416 static struct omap_rtc *omap_rtc_power_off_rtc;
417 
418 /*
419  * omap_rtc_poweroff: RTC-controlled power off
420  *
421  * The RTC can be used to control an external PMIC via the pmic_power_en pin,
422  * which can be configured to transition to OFF on ALARM2 events.
423  *
424  * Notes:
425  * The two-second alarm offset is the shortest offset possible as the alarm
426  * registers must be set before the next timer update and the offset
427  * calculation is too heavy for everything to be done within a single access
428  * period (~15 us).
429  *
430  * Called with local interrupts disabled.
431  */
omap_rtc_power_off(void)432 static void omap_rtc_power_off(void)
433 {
434 	struct omap_rtc *rtc = omap_rtc_power_off_rtc;
435 	struct rtc_time tm;
436 	unsigned long now;
437 	u32 val;
438 
439 	rtc->type->unlock(rtc);
440 	/* enable pmic_power_en control */
441 	val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
442 	rtc_writel(rtc, OMAP_RTC_PMIC_REG, val | OMAP_RTC_PMIC_POWER_EN_EN);
443 
444 	/* set alarm two seconds from now */
445 	omap_rtc_read_time_raw(rtc, &tm);
446 	bcd2tm(&tm);
447 	rtc_tm_to_time(&tm, &now);
448 	rtc_time_to_tm(now + 2, &tm);
449 
450 	if (tm2bcd(&tm) < 0) {
451 		dev_err(&rtc->rtc->dev, "power off failed\n");
452 		rtc->type->lock(rtc);
453 		return;
454 	}
455 
456 	rtc_wait_not_busy(rtc);
457 
458 	rtc_write(rtc, OMAP_RTC_ALARM2_SECONDS_REG, tm.tm_sec);
459 	rtc_write(rtc, OMAP_RTC_ALARM2_MINUTES_REG, tm.tm_min);
460 	rtc_write(rtc, OMAP_RTC_ALARM2_HOURS_REG, tm.tm_hour);
461 	rtc_write(rtc, OMAP_RTC_ALARM2_DAYS_REG, tm.tm_mday);
462 	rtc_write(rtc, OMAP_RTC_ALARM2_MONTHS_REG, tm.tm_mon);
463 	rtc_write(rtc, OMAP_RTC_ALARM2_YEARS_REG, tm.tm_year);
464 
465 	/*
466 	 * enable ALARM2 interrupt
467 	 *
468 	 * NOTE: this fails on AM3352 if rtc_write (writeb) is used
469 	 */
470 	val = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
471 	rtc_writel(rtc, OMAP_RTC_INTERRUPTS_REG,
472 			val | OMAP_RTC_INTERRUPTS_IT_ALARM2);
473 	rtc->type->lock(rtc);
474 
475 	/*
476 	 * Wait for alarm to trigger (within two seconds) and external PMIC to
477 	 * power off the system. Add a 500 ms margin for external latencies
478 	 * (e.g. debounce circuits).
479 	 */
480 	mdelay(2500);
481 }
482 
483 static const struct rtc_class_ops omap_rtc_ops = {
484 	.read_time	= omap_rtc_read_time,
485 	.set_time	= omap_rtc_set_time,
486 	.read_alarm	= omap_rtc_read_alarm,
487 	.set_alarm	= omap_rtc_set_alarm,
488 	.alarm_irq_enable = omap_rtc_alarm_irq_enable,
489 };
490 
491 static const struct omap_rtc_device_type omap_rtc_default_type = {
492 	.has_power_up_reset = true,
493 	.lock		= default_rtc_lock,
494 	.unlock		= default_rtc_unlock,
495 };
496 
497 static const struct omap_rtc_device_type omap_rtc_am3352_type = {
498 	.has_32kclk_en	= true,
499 	.has_irqwakeen	= true,
500 	.has_pmic_mode	= true,
501 	.lock		= am3352_rtc_lock,
502 	.unlock		= am3352_rtc_unlock,
503 };
504 
505 static const struct omap_rtc_device_type omap_rtc_da830_type = {
506 	.lock		= am3352_rtc_lock,
507 	.unlock		= am3352_rtc_unlock,
508 };
509 
510 static const struct platform_device_id omap_rtc_id_table[] = {
511 	{
512 		.name	= "omap_rtc",
513 		.driver_data = (kernel_ulong_t)&omap_rtc_default_type,
514 	}, {
515 		.name	= "am3352-rtc",
516 		.driver_data = (kernel_ulong_t)&omap_rtc_am3352_type,
517 	}, {
518 		.name	= "da830-rtc",
519 		.driver_data = (kernel_ulong_t)&omap_rtc_da830_type,
520 	}, {
521 		/* sentinel */
522 	}
523 };
524 MODULE_DEVICE_TABLE(platform, omap_rtc_id_table);
525 
526 static const struct of_device_id omap_rtc_of_match[] = {
527 	{
528 		.compatible	= "ti,am3352-rtc",
529 		.data		= &omap_rtc_am3352_type,
530 	}, {
531 		.compatible	= "ti,da830-rtc",
532 		.data		= &omap_rtc_da830_type,
533 	}, {
534 		/* sentinel */
535 	}
536 };
537 MODULE_DEVICE_TABLE(of, omap_rtc_of_match);
538 
539 static const struct pinctrl_pin_desc rtc_pins_desc[] = {
540 	PINCTRL_PIN(0, "ext_wakeup0"),
541 	PINCTRL_PIN(1, "ext_wakeup1"),
542 	PINCTRL_PIN(2, "ext_wakeup2"),
543 	PINCTRL_PIN(3, "ext_wakeup3"),
544 };
545 
rtc_pinctrl_get_groups_count(struct pinctrl_dev * pctldev)546 static int rtc_pinctrl_get_groups_count(struct pinctrl_dev *pctldev)
547 {
548 	return 0;
549 }
550 
rtc_pinctrl_get_group_name(struct pinctrl_dev * pctldev,unsigned int group)551 static const char *rtc_pinctrl_get_group_name(struct pinctrl_dev *pctldev,
552 					unsigned int group)
553 {
554 	return NULL;
555 }
556 
557 static const struct pinctrl_ops rtc_pinctrl_ops = {
558 	.get_groups_count = rtc_pinctrl_get_groups_count,
559 	.get_group_name = rtc_pinctrl_get_group_name,
560 	.dt_node_to_map = pinconf_generic_dt_node_to_map_pin,
561 	.dt_free_map = pinconf_generic_dt_free_map,
562 };
563 
564 #define PIN_CONFIG_ACTIVE_HIGH		(PIN_CONFIG_END + 1)
565 
566 static const struct pinconf_generic_params rtc_params[] = {
567 	{"ti,active-high", PIN_CONFIG_ACTIVE_HIGH, 0},
568 };
569 
570 #ifdef CONFIG_DEBUG_FS
571 static const struct pin_config_item rtc_conf_items[ARRAY_SIZE(rtc_params)] = {
572 	PCONFDUMP(PIN_CONFIG_ACTIVE_HIGH, "input active high", NULL, false),
573 };
574 #endif
575 
rtc_pinconf_get(struct pinctrl_dev * pctldev,unsigned int pin,unsigned long * config)576 static int rtc_pinconf_get(struct pinctrl_dev *pctldev,
577 			unsigned int pin, unsigned long *config)
578 {
579 	struct omap_rtc *rtc = pinctrl_dev_get_drvdata(pctldev);
580 	unsigned int param = pinconf_to_config_param(*config);
581 	u32 val;
582 	u16 arg = 0;
583 
584 	val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
585 
586 	switch (param) {
587 	case PIN_CONFIG_INPUT_ENABLE:
588 		if (!(val & OMAP_RTC_PMIC_EXT_WKUP_EN(pin)))
589 			return -EINVAL;
590 		break;
591 	case PIN_CONFIG_ACTIVE_HIGH:
592 		if (val & OMAP_RTC_PMIC_EXT_WKUP_POL(pin))
593 			return -EINVAL;
594 		break;
595 	default:
596 		return -ENOTSUPP;
597 	};
598 
599 	*config = pinconf_to_config_packed(param, arg);
600 
601 	return 0;
602 }
603 
rtc_pinconf_set(struct pinctrl_dev * pctldev,unsigned int pin,unsigned long * configs,unsigned int num_configs)604 static int rtc_pinconf_set(struct pinctrl_dev *pctldev,
605 			unsigned int pin, unsigned long *configs,
606 			unsigned int num_configs)
607 {
608 	struct omap_rtc *rtc = pinctrl_dev_get_drvdata(pctldev);
609 	u32 val;
610 	unsigned int param;
611 	u32 param_val;
612 	int i;
613 
614 	val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
615 
616 	/* active low by default */
617 	val |= OMAP_RTC_PMIC_EXT_WKUP_POL(pin);
618 
619 	for (i = 0; i < num_configs; i++) {
620 		param = pinconf_to_config_param(configs[i]);
621 		param_val = pinconf_to_config_argument(configs[i]);
622 
623 		switch (param) {
624 		case PIN_CONFIG_INPUT_ENABLE:
625 			if (param_val)
626 				val |= OMAP_RTC_PMIC_EXT_WKUP_EN(pin);
627 			else
628 				val &= ~OMAP_RTC_PMIC_EXT_WKUP_EN(pin);
629 			break;
630 		case PIN_CONFIG_ACTIVE_HIGH:
631 			val &= ~OMAP_RTC_PMIC_EXT_WKUP_POL(pin);
632 			break;
633 		default:
634 			dev_err(&rtc->rtc->dev, "Property %u not supported\n",
635 				param);
636 			return -ENOTSUPP;
637 		}
638 	}
639 
640 	rtc->type->unlock(rtc);
641 	rtc_writel(rtc, OMAP_RTC_PMIC_REG, val);
642 	rtc->type->lock(rtc);
643 
644 	return 0;
645 }
646 
647 static const struct pinconf_ops rtc_pinconf_ops = {
648 	.is_generic = true,
649 	.pin_config_get = rtc_pinconf_get,
650 	.pin_config_set = rtc_pinconf_set,
651 };
652 
653 static struct pinctrl_desc rtc_pinctrl_desc = {
654 	.pins = rtc_pins_desc,
655 	.npins = ARRAY_SIZE(rtc_pins_desc),
656 	.pctlops = &rtc_pinctrl_ops,
657 	.confops = &rtc_pinconf_ops,
658 	.custom_params = rtc_params,
659 	.num_custom_params = ARRAY_SIZE(rtc_params),
660 #ifdef CONFIG_DEBUG_FS
661 	.custom_conf_items = rtc_conf_items,
662 #endif
663 	.owner = THIS_MODULE,
664 };
665 
omap_rtc_scratch_read(void * priv,unsigned int offset,void * _val,size_t bytes)666 static int omap_rtc_scratch_read(void *priv, unsigned int offset, void *_val,
667 				 size_t bytes)
668 {
669 	struct omap_rtc	*rtc = priv;
670 	u32 *val = _val;
671 	int i;
672 
673 	for (i = 0; i < bytes / 4; i++)
674 		val[i] = rtc_readl(rtc,
675 				   OMAP_RTC_SCRATCH0_REG + offset + (i * 4));
676 
677 	return 0;
678 }
679 
omap_rtc_scratch_write(void * priv,unsigned int offset,void * _val,size_t bytes)680 static int omap_rtc_scratch_write(void *priv, unsigned int offset, void *_val,
681 				  size_t bytes)
682 {
683 	struct omap_rtc	*rtc = priv;
684 	u32 *val = _val;
685 	int i;
686 
687 	rtc->type->unlock(rtc);
688 	for (i = 0; i < bytes / 4; i++)
689 		rtc_writel(rtc,
690 			   OMAP_RTC_SCRATCH0_REG + offset + (i * 4), val[i]);
691 	rtc->type->lock(rtc);
692 
693 	return 0;
694 }
695 
696 static struct nvmem_config omap_rtc_nvmem_config = {
697 	.name = "omap_rtc_scratch",
698 	.word_size = 4,
699 	.stride = 4,
700 	.size = OMAP_RTC_KICK0_REG - OMAP_RTC_SCRATCH0_REG,
701 	.reg_read = omap_rtc_scratch_read,
702 	.reg_write = omap_rtc_scratch_write,
703 };
704 
omap_rtc_probe(struct platform_device * pdev)705 static int omap_rtc_probe(struct platform_device *pdev)
706 {
707 	struct omap_rtc	*rtc;
708 	struct resource	*res;
709 	u8 reg, mask, new_ctrl;
710 	const struct platform_device_id *id_entry;
711 	const struct of_device_id *of_id;
712 	int ret;
713 
714 	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
715 	if (!rtc)
716 		return -ENOMEM;
717 
718 	of_id = of_match_device(omap_rtc_of_match, &pdev->dev);
719 	if (of_id) {
720 		rtc->type = of_id->data;
721 		rtc->is_pmic_controller = rtc->type->has_pmic_mode &&
722 				of_property_read_bool(pdev->dev.of_node,
723 						"system-power-controller");
724 	} else {
725 		id_entry = platform_get_device_id(pdev);
726 		rtc->type = (void *)id_entry->driver_data;
727 	}
728 
729 	rtc->irq_timer = platform_get_irq(pdev, 0);
730 	if (rtc->irq_timer <= 0)
731 		return -ENOENT;
732 
733 	rtc->irq_alarm = platform_get_irq(pdev, 1);
734 	if (rtc->irq_alarm <= 0)
735 		return -ENOENT;
736 
737 	rtc->clk = devm_clk_get(&pdev->dev, "ext-clk");
738 	if (!IS_ERR(rtc->clk))
739 		rtc->has_ext_clk = true;
740 	else
741 		rtc->clk = devm_clk_get(&pdev->dev, "int-clk");
742 
743 	if (!IS_ERR(rtc->clk))
744 		clk_prepare_enable(rtc->clk);
745 
746 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
747 	rtc->base = devm_ioremap_resource(&pdev->dev, res);
748 	if (IS_ERR(rtc->base)) {
749 		clk_disable_unprepare(rtc->clk);
750 		return PTR_ERR(rtc->base);
751 	}
752 
753 	platform_set_drvdata(pdev, rtc);
754 
755 	/* Enable the clock/module so that we can access the registers */
756 	pm_runtime_enable(&pdev->dev);
757 	pm_runtime_get_sync(&pdev->dev);
758 
759 	rtc->type->unlock(rtc);
760 
761 	/*
762 	 * disable interrupts
763 	 *
764 	 * NOTE: ALARM2 is not cleared on AM3352 if rtc_write (writeb) is used
765 	 */
766 	rtc_writel(rtc, OMAP_RTC_INTERRUPTS_REG, 0);
767 
768 	/* enable RTC functional clock */
769 	if (rtc->type->has_32kclk_en) {
770 		reg = rtc_read(rtc, OMAP_RTC_OSC_REG);
771 		rtc_writel(rtc, OMAP_RTC_OSC_REG,
772 				reg | OMAP_RTC_OSC_32KCLK_EN);
773 	}
774 
775 	/* clear old status */
776 	reg = rtc_read(rtc, OMAP_RTC_STATUS_REG);
777 
778 	mask = OMAP_RTC_STATUS_ALARM;
779 
780 	if (rtc->type->has_pmic_mode)
781 		mask |= OMAP_RTC_STATUS_ALARM2;
782 
783 	if (rtc->type->has_power_up_reset) {
784 		mask |= OMAP_RTC_STATUS_POWER_UP;
785 		if (reg & OMAP_RTC_STATUS_POWER_UP)
786 			dev_info(&pdev->dev, "RTC power up reset detected\n");
787 	}
788 
789 	if (reg & mask)
790 		rtc_write(rtc, OMAP_RTC_STATUS_REG, reg & mask);
791 
792 	/* On boards with split power, RTC_ON_NOFF won't reset the RTC */
793 	reg = rtc_read(rtc, OMAP_RTC_CTRL_REG);
794 	if (reg & OMAP_RTC_CTRL_STOP)
795 		dev_info(&pdev->dev, "already running\n");
796 
797 	/* force to 24 hour mode */
798 	new_ctrl = reg & (OMAP_RTC_CTRL_SPLIT | OMAP_RTC_CTRL_AUTO_COMP);
799 	new_ctrl |= OMAP_RTC_CTRL_STOP;
800 
801 	/*
802 	 * BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE:
803 	 *
804 	 *  - Device wake-up capability setting should come through chip
805 	 *    init logic. OMAP1 boards should initialize the "wakeup capable"
806 	 *    flag in the platform device if the board is wired right for
807 	 *    being woken up by RTC alarm. For OMAP-L138, this capability
808 	 *    is built into the SoC by the "Deep Sleep" capability.
809 	 *
810 	 *  - Boards wired so RTC_ON_nOFF is used as the reset signal,
811 	 *    rather than nPWRON_RESET, should forcibly enable split
812 	 *    power mode.  (Some chip errata report that RTC_CTRL_SPLIT
813 	 *    is write-only, and always reads as zero...)
814 	 */
815 
816 	if (new_ctrl & OMAP_RTC_CTRL_SPLIT)
817 		dev_info(&pdev->dev, "split power mode\n");
818 
819 	if (reg != new_ctrl)
820 		rtc_write(rtc, OMAP_RTC_CTRL_REG, new_ctrl);
821 
822 	/*
823 	 * If we have the external clock then switch to it so we can keep
824 	 * ticking across suspend.
825 	 */
826 	if (rtc->has_ext_clk) {
827 		reg = rtc_read(rtc, OMAP_RTC_OSC_REG);
828 		reg &= ~OMAP_RTC_OSC_OSC32K_GZ_DISABLE;
829 		reg |= OMAP_RTC_OSC_32KCLK_EN | OMAP_RTC_OSC_SEL_32KCLK_SRC;
830 		rtc_writel(rtc, OMAP_RTC_OSC_REG, reg);
831 	}
832 
833 	rtc->type->lock(rtc);
834 
835 	device_init_wakeup(&pdev->dev, true);
836 
837 	rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
838 	if (IS_ERR(rtc->rtc)) {
839 		ret = PTR_ERR(rtc->rtc);
840 		goto err;
841 	}
842 
843 	rtc->rtc->ops = &omap_rtc_ops;
844 	omap_rtc_nvmem_config.priv = rtc;
845 
846 	/* handle periodic and alarm irqs */
847 	ret = devm_request_irq(&pdev->dev, rtc->irq_timer, rtc_irq, 0,
848 			dev_name(&rtc->rtc->dev), rtc);
849 	if (ret)
850 		goto err;
851 
852 	if (rtc->irq_timer != rtc->irq_alarm) {
853 		ret = devm_request_irq(&pdev->dev, rtc->irq_alarm, rtc_irq, 0,
854 				dev_name(&rtc->rtc->dev), rtc);
855 		if (ret)
856 			goto err;
857 	}
858 
859 	/* Support ext_wakeup pinconf */
860 	rtc_pinctrl_desc.name = dev_name(&pdev->dev);
861 
862 	rtc->pctldev = pinctrl_register(&rtc_pinctrl_desc, &pdev->dev, rtc);
863 	if (IS_ERR(rtc->pctldev)) {
864 		dev_err(&pdev->dev, "Couldn't register pinctrl driver\n");
865 		ret = PTR_ERR(rtc->pctldev);
866 		goto err;
867 	}
868 
869 	ret = rtc_register_device(rtc->rtc);
870 	if (ret)
871 		goto err_deregister_pinctrl;
872 
873 	rtc_nvmem_register(rtc->rtc, &omap_rtc_nvmem_config);
874 
875 	if (rtc->is_pmic_controller) {
876 		if (!pm_power_off) {
877 			omap_rtc_power_off_rtc = rtc;
878 			pm_power_off = omap_rtc_power_off;
879 		}
880 	}
881 
882 	return 0;
883 
884 err_deregister_pinctrl:
885 	pinctrl_unregister(rtc->pctldev);
886 err:
887 	clk_disable_unprepare(rtc->clk);
888 	device_init_wakeup(&pdev->dev, false);
889 	rtc->type->lock(rtc);
890 	pm_runtime_put_sync(&pdev->dev);
891 	pm_runtime_disable(&pdev->dev);
892 
893 	return ret;
894 }
895 
omap_rtc_remove(struct platform_device * pdev)896 static int omap_rtc_remove(struct platform_device *pdev)
897 {
898 	struct omap_rtc *rtc = platform_get_drvdata(pdev);
899 	u8 reg;
900 
901 	if (pm_power_off == omap_rtc_power_off &&
902 			omap_rtc_power_off_rtc == rtc) {
903 		pm_power_off = NULL;
904 		omap_rtc_power_off_rtc = NULL;
905 	}
906 
907 	device_init_wakeup(&pdev->dev, 0);
908 
909 	if (!IS_ERR(rtc->clk))
910 		clk_disable_unprepare(rtc->clk);
911 
912 	rtc->type->unlock(rtc);
913 	/* leave rtc running, but disable irqs */
914 	rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, 0);
915 
916 	if (rtc->has_ext_clk) {
917 		reg = rtc_read(rtc, OMAP_RTC_OSC_REG);
918 		reg &= ~OMAP_RTC_OSC_SEL_32KCLK_SRC;
919 		rtc_write(rtc, OMAP_RTC_OSC_REG, reg);
920 	}
921 
922 	rtc->type->lock(rtc);
923 
924 	/* Disable the clock/module */
925 	pm_runtime_put_sync(&pdev->dev);
926 	pm_runtime_disable(&pdev->dev);
927 
928 	/* Remove ext_wakeup pinconf */
929 	pinctrl_unregister(rtc->pctldev);
930 
931 	return 0;
932 }
933 
omap_rtc_suspend(struct device * dev)934 static int __maybe_unused omap_rtc_suspend(struct device *dev)
935 {
936 	struct omap_rtc *rtc = dev_get_drvdata(dev);
937 
938 	rtc->interrupts_reg = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
939 
940 	rtc->type->unlock(rtc);
941 	/*
942 	 * FIXME: the RTC alarm is not currently acting as a wakeup event
943 	 * source on some platforms, and in fact this enable() call is just
944 	 * saving a flag that's never used...
945 	 */
946 	if (device_may_wakeup(dev))
947 		enable_irq_wake(rtc->irq_alarm);
948 	else
949 		rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, 0);
950 	rtc->type->lock(rtc);
951 
952 	rtc->is_suspending = true;
953 
954 	return 0;
955 }
956 
omap_rtc_resume(struct device * dev)957 static int __maybe_unused omap_rtc_resume(struct device *dev)
958 {
959 	struct omap_rtc *rtc = dev_get_drvdata(dev);
960 
961 	rtc->type->unlock(rtc);
962 	if (device_may_wakeup(dev))
963 		disable_irq_wake(rtc->irq_alarm);
964 	else
965 		rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, rtc->interrupts_reg);
966 	rtc->type->lock(rtc);
967 
968 	rtc->is_suspending = false;
969 
970 	return 0;
971 }
972 
omap_rtc_runtime_suspend(struct device * dev)973 static int __maybe_unused omap_rtc_runtime_suspend(struct device *dev)
974 {
975 	struct omap_rtc *rtc = dev_get_drvdata(dev);
976 
977 	if (rtc->is_suspending && !rtc->has_ext_clk)
978 		return -EBUSY;
979 
980 	return 0;
981 }
982 
983 static const struct dev_pm_ops omap_rtc_pm_ops = {
984 	SET_SYSTEM_SLEEP_PM_OPS(omap_rtc_suspend, omap_rtc_resume)
985 	SET_RUNTIME_PM_OPS(omap_rtc_runtime_suspend, NULL, NULL)
986 };
987 
omap_rtc_shutdown(struct platform_device * pdev)988 static void omap_rtc_shutdown(struct platform_device *pdev)
989 {
990 	struct omap_rtc *rtc = platform_get_drvdata(pdev);
991 	u8 mask;
992 
993 	/*
994 	 * Keep the ALARM interrupt enabled to allow the system to power up on
995 	 * alarm events.
996 	 */
997 	rtc->type->unlock(rtc);
998 	mask = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
999 	mask &= OMAP_RTC_INTERRUPTS_IT_ALARM;
1000 	rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, mask);
1001 	rtc->type->lock(rtc);
1002 }
1003 
1004 static struct platform_driver omap_rtc_driver = {
1005 	.probe		= omap_rtc_probe,
1006 	.remove		= omap_rtc_remove,
1007 	.shutdown	= omap_rtc_shutdown,
1008 	.driver		= {
1009 		.name	= "omap_rtc",
1010 		.pm	= &omap_rtc_pm_ops,
1011 		.of_match_table = omap_rtc_of_match,
1012 	},
1013 	.id_table	= omap_rtc_id_table,
1014 };
1015 
1016 module_platform_driver(omap_rtc_driver);
1017 
1018 MODULE_ALIAS("platform:omap_rtc");
1019 MODULE_AUTHOR("George G. Davis (and others)");
1020 MODULE_LICENSE("GPL");
1021