xref: /linux/drivers/rtc/rtc-twl.c (revision 0e287d31b62bb53ad81d5e59778384a40f8b6f56)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * rtc-twl.c -- TWL Real Time Clock interface
4  *
5  * Copyright (C) 2007 MontaVista Software, Inc
6  * Author: Alexandre Rusev <source@mvista.com>
7  *
8  * Based on original TI driver twl4030-rtc.c
9  *   Copyright (C) 2006 Texas Instruments, Inc.
10  *
11  * Based on rtc-omap.c
12  *   Copyright (C) 2003 MontaVista Software, Inc.
13  *   Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com>
14  *   Copyright (C) 2006 David Brownell
15  */
16 
17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 
19 #include <linux/kernel.h>
20 #include <linux/errno.h>
21 #include <linux/init.h>
22 #include <linux/module.h>
23 #include <linux/types.h>
24 #include <linux/rtc.h>
25 #include <linux/bcd.h>
26 #include <linux/platform_device.h>
27 #include <linux/interrupt.h>
28 #include <linux/of.h>
29 
30 #include <linux/mfd/twl.h>
31 
32 enum twl_class {
33 	TWL_4030 = 0,
34 	TWL_6030,
35 };
36 
37 /*
38  * RTC block register offsets (use TWL_MODULE_RTC)
39  */
40 enum {
41 	REG_SECONDS_REG = 0,
42 	REG_MINUTES_REG,
43 	REG_HOURS_REG,
44 	REG_DAYS_REG,
45 	REG_MONTHS_REG,
46 	REG_YEARS_REG,
47 	REG_WEEKS_REG,
48 
49 	REG_ALARM_SECONDS_REG,
50 	REG_ALARM_MINUTES_REG,
51 	REG_ALARM_HOURS_REG,
52 	REG_ALARM_DAYS_REG,
53 	REG_ALARM_MONTHS_REG,
54 	REG_ALARM_YEARS_REG,
55 
56 	REG_RTC_CTRL_REG,
57 	REG_RTC_STATUS_REG,
58 	REG_RTC_INTERRUPTS_REG,
59 
60 	REG_RTC_COMP_LSB_REG,
61 	REG_RTC_COMP_MSB_REG,
62 };
63 static const u8 twl4030_rtc_reg_map[] = {
64 	[REG_SECONDS_REG] = 0x00,
65 	[REG_MINUTES_REG] = 0x01,
66 	[REG_HOURS_REG] = 0x02,
67 	[REG_DAYS_REG] = 0x03,
68 	[REG_MONTHS_REG] = 0x04,
69 	[REG_YEARS_REG] = 0x05,
70 	[REG_WEEKS_REG] = 0x06,
71 
72 	[REG_ALARM_SECONDS_REG] = 0x07,
73 	[REG_ALARM_MINUTES_REG] = 0x08,
74 	[REG_ALARM_HOURS_REG] = 0x09,
75 	[REG_ALARM_DAYS_REG] = 0x0A,
76 	[REG_ALARM_MONTHS_REG] = 0x0B,
77 	[REG_ALARM_YEARS_REG] = 0x0C,
78 
79 	[REG_RTC_CTRL_REG] = 0x0D,
80 	[REG_RTC_STATUS_REG] = 0x0E,
81 	[REG_RTC_INTERRUPTS_REG] = 0x0F,
82 
83 	[REG_RTC_COMP_LSB_REG] = 0x10,
84 	[REG_RTC_COMP_MSB_REG] = 0x11,
85 };
86 static const u8 twl6030_rtc_reg_map[] = {
87 	[REG_SECONDS_REG] = 0x00,
88 	[REG_MINUTES_REG] = 0x01,
89 	[REG_HOURS_REG] = 0x02,
90 	[REG_DAYS_REG] = 0x03,
91 	[REG_MONTHS_REG] = 0x04,
92 	[REG_YEARS_REG] = 0x05,
93 	[REG_WEEKS_REG] = 0x06,
94 
95 	[REG_ALARM_SECONDS_REG] = 0x08,
96 	[REG_ALARM_MINUTES_REG] = 0x09,
97 	[REG_ALARM_HOURS_REG] = 0x0A,
98 	[REG_ALARM_DAYS_REG] = 0x0B,
99 	[REG_ALARM_MONTHS_REG] = 0x0C,
100 	[REG_ALARM_YEARS_REG] = 0x0D,
101 
102 	[REG_RTC_CTRL_REG] = 0x10,
103 	[REG_RTC_STATUS_REG] = 0x11,
104 	[REG_RTC_INTERRUPTS_REG] = 0x12,
105 
106 	[REG_RTC_COMP_LSB_REG] = 0x13,
107 	[REG_RTC_COMP_MSB_REG] = 0x14,
108 };
109 
110 /* RTC_CTRL_REG bitfields */
111 #define BIT_RTC_CTRL_REG_STOP_RTC_M              0x01
112 #define BIT_RTC_CTRL_REG_ROUND_30S_M             0x02
113 #define BIT_RTC_CTRL_REG_AUTO_COMP_M             0x04
114 #define BIT_RTC_CTRL_REG_MODE_12_24_M            0x08
115 #define BIT_RTC_CTRL_REG_TEST_MODE_M             0x10
116 #define BIT_RTC_CTRL_REG_SET_32_COUNTER_M        0x20
117 #define BIT_RTC_CTRL_REG_GET_TIME_M              0x40
118 #define BIT_RTC_CTRL_REG_RTC_V_OPT               0x80
119 
120 /* RTC_STATUS_REG bitfields */
121 #define BIT_RTC_STATUS_REG_RUN_M                 0x02
122 #define BIT_RTC_STATUS_REG_1S_EVENT_M            0x04
123 #define BIT_RTC_STATUS_REG_1M_EVENT_M            0x08
124 #define BIT_RTC_STATUS_REG_1H_EVENT_M            0x10
125 #define BIT_RTC_STATUS_REG_1D_EVENT_M            0x20
126 #define BIT_RTC_STATUS_REG_ALARM_M               0x40
127 #define BIT_RTC_STATUS_REG_POWER_UP_M            0x80
128 
129 /* RTC_INTERRUPTS_REG bitfields */
130 #define BIT_RTC_INTERRUPTS_REG_EVERY_M           0x03
131 #define BIT_RTC_INTERRUPTS_REG_IT_TIMER_M        0x04
132 #define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M        0x08
133 
134 
135 /* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */
136 #define ALL_TIME_REGS		6
137 
138 /*----------------------------------------------------------------------*/
139 struct twl_rtc {
140 	struct device *dev;
141 	struct rtc_device *rtc;
142 	u8 *reg_map;
143 	/*
144 	 * Cache the value for timer/alarm interrupts register; this is
145 	 * only changed by callers holding rtc ops lock (or resume).
146 	 */
147 	unsigned char rtc_irq_bits;
148 	bool wake_enabled;
149 #ifdef CONFIG_PM_SLEEP
150 	unsigned char irqstat;
151 #endif
152 	enum twl_class class;
153 };
154 
155 /*
156  * Supports 1 byte read from TWL RTC register.
157  */
twl_rtc_read_u8(struct twl_rtc * twl_rtc,u8 * data,u8 reg)158 static int twl_rtc_read_u8(struct twl_rtc *twl_rtc, u8 *data, u8 reg)
159 {
160 	int ret;
161 
162 	ret = twl_i2c_read_u8(TWL_MODULE_RTC, data, (twl_rtc->reg_map[reg]));
163 	if (ret < 0)
164 		pr_err("Could not read TWL register %X - error %d\n", reg, ret);
165 	return ret;
166 }
167 
168 /*
169  * Supports 1 byte write to TWL RTC registers.
170  */
twl_rtc_write_u8(struct twl_rtc * twl_rtc,u8 data,u8 reg)171 static int twl_rtc_write_u8(struct twl_rtc *twl_rtc, u8 data, u8 reg)
172 {
173 	int ret;
174 
175 	ret = twl_i2c_write_u8(TWL_MODULE_RTC, data, (twl_rtc->reg_map[reg]));
176 	if (ret < 0)
177 		pr_err("Could not write TWL register %X - error %d\n",
178 		       reg, ret);
179 	return ret;
180 }
181 
182 /*
183  * Enable 1/second update and/or alarm interrupts.
184  */
set_rtc_irq_bit(struct twl_rtc * twl_rtc,unsigned char bit)185 static int set_rtc_irq_bit(struct twl_rtc *twl_rtc, unsigned char bit)
186 {
187 	unsigned char val;
188 	int ret;
189 
190 	/* if the bit is set, return from here */
191 	if (twl_rtc->rtc_irq_bits & bit)
192 		return 0;
193 
194 	val = twl_rtc->rtc_irq_bits | bit;
195 	val &= ~BIT_RTC_INTERRUPTS_REG_EVERY_M;
196 	ret = twl_rtc_write_u8(twl_rtc, val, REG_RTC_INTERRUPTS_REG);
197 	if (ret == 0)
198 		twl_rtc->rtc_irq_bits = val;
199 
200 	return ret;
201 }
202 
203 /*
204  * Disable update and/or alarm interrupts.
205  */
mask_rtc_irq_bit(struct twl_rtc * twl_rtc,unsigned char bit)206 static int mask_rtc_irq_bit(struct twl_rtc *twl_rtc, unsigned char bit)
207 {
208 	unsigned char val;
209 	int ret;
210 
211 	/* if the bit is clear, return from here */
212 	if (!(twl_rtc->rtc_irq_bits & bit))
213 		return 0;
214 
215 	val = twl_rtc->rtc_irq_bits & ~bit;
216 	ret = twl_rtc_write_u8(twl_rtc, val, REG_RTC_INTERRUPTS_REG);
217 	if (ret == 0)
218 		twl_rtc->rtc_irq_bits = val;
219 
220 	return ret;
221 }
222 
twl_rtc_alarm_irq_enable(struct device * dev,unsigned enabled)223 static int twl_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
224 {
225 	struct platform_device *pdev = to_platform_device(dev);
226 	struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
227 	int irq = platform_get_irq(pdev, 0);
228 	int ret;
229 
230 	if (enabled) {
231 		ret = set_rtc_irq_bit(twl_rtc,
232 				      BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
233 		if (device_can_wakeup(dev) && !twl_rtc->wake_enabled) {
234 			enable_irq_wake(irq);
235 			twl_rtc->wake_enabled = true;
236 		}
237 	} else {
238 		ret = mask_rtc_irq_bit(twl_rtc,
239 				       BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
240 		if (twl_rtc->wake_enabled) {
241 			disable_irq_wake(irq);
242 			twl_rtc->wake_enabled = false;
243 		}
244 	}
245 
246 	return ret;
247 }
248 
249 /*
250  * Gets current TWL RTC time and date parameters.
251  *
252  * The RTC's time/alarm representation is not what gmtime(3) requires
253  * Linux to use:
254  *
255  *  - Months are 1..12 vs Linux 0-11
256  *  - Years are 0..99 vs Linux 1900..N (we assume 21st century)
257  */
twl_rtc_read_time(struct device * dev,struct rtc_time * tm)258 static int twl_rtc_read_time(struct device *dev, struct rtc_time *tm)
259 {
260 	struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
261 	unsigned char rtc_data[ALL_TIME_REGS];
262 	int ret;
263 	u8 save_control;
264 	u8 rtc_control;
265 
266 	ret = twl_rtc_read_u8(twl_rtc, &save_control, REG_RTC_CTRL_REG);
267 	if (ret < 0) {
268 		dev_err(dev, "%s: reading CTRL_REG, error %d\n", __func__, ret);
269 		return ret;
270 	}
271 	/* for twl6030/32 make sure BIT_RTC_CTRL_REG_GET_TIME_M is clear */
272 	if (twl_rtc->class == TWL_6030) {
273 		if (save_control & BIT_RTC_CTRL_REG_GET_TIME_M) {
274 			save_control &= ~BIT_RTC_CTRL_REG_GET_TIME_M;
275 			ret = twl_rtc_write_u8(twl_rtc, save_control,
276 					       REG_RTC_CTRL_REG);
277 			if (ret < 0) {
278 				dev_err(dev, "%s clr GET_TIME, error %d\n",
279 					__func__, ret);
280 				return ret;
281 			}
282 		}
283 	}
284 
285 	/* Copy RTC counting registers to static registers or latches */
286 	rtc_control = save_control | BIT_RTC_CTRL_REG_GET_TIME_M;
287 
288 	/* for twl6030/32 enable read access to static shadowed registers */
289 	if (twl_rtc->class == TWL_6030)
290 		rtc_control |= BIT_RTC_CTRL_REG_RTC_V_OPT;
291 
292 	ret = twl_rtc_write_u8(twl_rtc, rtc_control, REG_RTC_CTRL_REG);
293 	if (ret < 0) {
294 		dev_err(dev, "%s: writing CTRL_REG, error %d\n", __func__, ret);
295 		return ret;
296 	}
297 
298 	ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data,
299 			(twl_rtc->reg_map[REG_SECONDS_REG]), ALL_TIME_REGS);
300 
301 	if (ret < 0) {
302 		dev_err(dev, "%s: reading data, error %d\n", __func__, ret);
303 		return ret;
304 	}
305 
306 	/* for twl6030 restore original state of rtc control register */
307 	if (twl_rtc->class == TWL_6030) {
308 		ret = twl_rtc_write_u8(twl_rtc, save_control, REG_RTC_CTRL_REG);
309 		if (ret < 0) {
310 			dev_err(dev, "%s: restore CTRL_REG, error %d\n",
311 				__func__, ret);
312 			return ret;
313 		}
314 	}
315 
316 	tm->tm_sec = bcd2bin(rtc_data[0]);
317 	tm->tm_min = bcd2bin(rtc_data[1]);
318 	tm->tm_hour = bcd2bin(rtc_data[2]);
319 	tm->tm_mday = bcd2bin(rtc_data[3]);
320 	tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
321 	tm->tm_year = bcd2bin(rtc_data[5]) + 100;
322 
323 	return ret;
324 }
325 
twl_rtc_set_time(struct device * dev,struct rtc_time * tm)326 static int twl_rtc_set_time(struct device *dev, struct rtc_time *tm)
327 {
328 	struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
329 	unsigned char save_control;
330 	unsigned char rtc_data[ALL_TIME_REGS];
331 	int ret;
332 
333 	rtc_data[0] = bin2bcd(tm->tm_sec);
334 	rtc_data[1] = bin2bcd(tm->tm_min);
335 	rtc_data[2] = bin2bcd(tm->tm_hour);
336 	rtc_data[3] = bin2bcd(tm->tm_mday);
337 	rtc_data[4] = bin2bcd(tm->tm_mon + 1);
338 	rtc_data[5] = bin2bcd(tm->tm_year - 100);
339 
340 	/* Stop RTC while updating the TC registers */
341 	ret = twl_rtc_read_u8(twl_rtc, &save_control, REG_RTC_CTRL_REG);
342 	if (ret < 0)
343 		goto out;
344 
345 	save_control &= ~BIT_RTC_CTRL_REG_STOP_RTC_M;
346 	ret = twl_rtc_write_u8(twl_rtc, save_control, REG_RTC_CTRL_REG);
347 	if (ret < 0)
348 		goto out;
349 
350 	/* update all the time registers in one shot */
351 	ret = twl_i2c_write(TWL_MODULE_RTC, rtc_data,
352 		(twl_rtc->reg_map[REG_SECONDS_REG]), ALL_TIME_REGS);
353 	if (ret < 0) {
354 		dev_err(dev, "rtc_set_time error %d\n", ret);
355 		goto out;
356 	}
357 
358 	/* Start back RTC */
359 	save_control |= BIT_RTC_CTRL_REG_STOP_RTC_M;
360 	ret = twl_rtc_write_u8(twl_rtc, save_control, REG_RTC_CTRL_REG);
361 
362 out:
363 	return ret;
364 }
365 
366 /*
367  * Gets current TWL RTC alarm time.
368  */
twl_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alm)369 static int twl_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
370 {
371 	struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
372 	unsigned char rtc_data[ALL_TIME_REGS];
373 	int ret;
374 
375 	ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data,
376 			twl_rtc->reg_map[REG_ALARM_SECONDS_REG], ALL_TIME_REGS);
377 	if (ret < 0) {
378 		dev_err(dev, "rtc_read_alarm error %d\n", ret);
379 		return ret;
380 	}
381 
382 	/* some of these fields may be wildcard/"match all" */
383 	alm->time.tm_sec = bcd2bin(rtc_data[0]);
384 	alm->time.tm_min = bcd2bin(rtc_data[1]);
385 	alm->time.tm_hour = bcd2bin(rtc_data[2]);
386 	alm->time.tm_mday = bcd2bin(rtc_data[3]);
387 	alm->time.tm_mon = bcd2bin(rtc_data[4]) - 1;
388 	alm->time.tm_year = bcd2bin(rtc_data[5]) + 100;
389 
390 	/* report cached alarm enable state */
391 	if (twl_rtc->rtc_irq_bits & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M)
392 		alm->enabled = 1;
393 
394 	return ret;
395 }
396 
twl_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alm)397 static int twl_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
398 {
399 	struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
400 
401 	unsigned char alarm_data[ALL_TIME_REGS];
402 	int ret;
403 
404 	ret = twl_rtc_alarm_irq_enable(dev, 0);
405 	if (ret)
406 		goto out;
407 
408 	alarm_data[0] = bin2bcd(alm->time.tm_sec);
409 	alarm_data[1] = bin2bcd(alm->time.tm_min);
410 	alarm_data[2] = bin2bcd(alm->time.tm_hour);
411 	alarm_data[3] = bin2bcd(alm->time.tm_mday);
412 	alarm_data[4] = bin2bcd(alm->time.tm_mon + 1);
413 	alarm_data[5] = bin2bcd(alm->time.tm_year - 100);
414 
415 	/* update all the alarm registers in one shot */
416 	ret = twl_i2c_write(TWL_MODULE_RTC, alarm_data,
417 			twl_rtc->reg_map[REG_ALARM_SECONDS_REG], ALL_TIME_REGS);
418 	if (ret) {
419 		dev_err(dev, "rtc_set_alarm error %d\n", ret);
420 		goto out;
421 	}
422 
423 	if (alm->enabled)
424 		ret = twl_rtc_alarm_irq_enable(dev, 1);
425 out:
426 	return ret;
427 }
428 
twl_rtc_interrupt(int irq,void * data)429 static irqreturn_t twl_rtc_interrupt(int irq, void *data)
430 {
431 	struct twl_rtc *twl_rtc = data;
432 	unsigned long events;
433 	int ret = IRQ_NONE;
434 	int res;
435 	u8 rd_reg;
436 
437 	res = twl_rtc_read_u8(twl_rtc, &rd_reg, REG_RTC_STATUS_REG);
438 	if (res)
439 		goto out;
440 	/*
441 	 * Figure out source of interrupt: ALARM or TIMER in RTC_STATUS_REG.
442 	 * only one (ALARM or RTC) interrupt source may be enabled
443 	 * at time, we also could check our results
444 	 * by reading RTS_INTERRUPTS_REGISTER[IT_TIMER,IT_ALARM]
445 	 */
446 	if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
447 		events = RTC_IRQF | RTC_AF;
448 	else
449 		events = RTC_IRQF | RTC_PF;
450 
451 	res = twl_rtc_write_u8(twl_rtc, BIT_RTC_STATUS_REG_ALARM_M,
452 			       REG_RTC_STATUS_REG);
453 	if (res)
454 		goto out;
455 
456 	if (twl_rtc->class == TWL_4030) {
457 		/* Clear on Read enabled. RTC_IT bit of TWL4030_INT_PWR_ISR1
458 		 * needs 2 reads to clear the interrupt. One read is done in
459 		 * do_twl_pwrirq(). Doing the second read, to clear
460 		 * the bit.
461 		 *
462 		 * FIXME the reason PWR_ISR1 needs an extra read is that
463 		 * RTC_IF retriggered until we cleared REG_ALARM_M above.
464 		 * But re-reading like this is a bad hack; by doing so we
465 		 * risk wrongly clearing status for some other IRQ (losing
466 		 * the interrupt).  Be smarter about handling RTC_UF ...
467 		 */
468 		res = twl_i2c_read_u8(TWL4030_MODULE_INT,
469 			&rd_reg, TWL4030_INT_PWR_ISR1);
470 		if (res)
471 			goto out;
472 	}
473 
474 	/* Notify RTC core on event */
475 	rtc_update_irq(twl_rtc->rtc, 1, events);
476 
477 	ret = IRQ_HANDLED;
478 out:
479 	return ret;
480 }
481 
482 static const struct rtc_class_ops twl_rtc_ops = {
483 	.read_time	= twl_rtc_read_time,
484 	.set_time	= twl_rtc_set_time,
485 	.read_alarm	= twl_rtc_read_alarm,
486 	.set_alarm	= twl_rtc_set_alarm,
487 	.alarm_irq_enable = twl_rtc_alarm_irq_enable,
488 };
489 
twl_nvram_read(void * priv,unsigned int offset,void * val,size_t bytes)490 static int twl_nvram_read(void *priv, unsigned int offset, void *val,
491 			  size_t bytes)
492 {
493 	return twl_i2c_read((long)priv, val, offset, bytes);
494 }
495 
twl_nvram_write(void * priv,unsigned int offset,void * val,size_t bytes)496 static int twl_nvram_write(void *priv, unsigned int offset, void *val,
497 			   size_t bytes)
498 {
499 	return twl_i2c_write((long)priv, val, offset, bytes);
500 }
501 
502 /*----------------------------------------------------------------------*/
503 
twl_rtc_probe(struct platform_device * pdev)504 static int twl_rtc_probe(struct platform_device *pdev)
505 {
506 	struct twl_rtc *twl_rtc;
507 	struct nvmem_config nvmem_cfg;
508 	struct device_node *np = pdev->dev.of_node;
509 	int ret = -EINVAL;
510 	int irq = platform_get_irq(pdev, 0);
511 	u8 rd_reg;
512 
513 	if (!np) {
514 		dev_err(&pdev->dev, "no DT info\n");
515 		return -EINVAL;
516 	}
517 
518 	if (irq <= 0)
519 		return ret;
520 
521 	twl_rtc = devm_kzalloc(&pdev->dev, sizeof(*twl_rtc), GFP_KERNEL);
522 	if (!twl_rtc)
523 		return -ENOMEM;
524 
525 	if (twl_class_is_4030()) {
526 		twl_rtc->class = TWL_4030;
527 		twl_rtc->reg_map = (u8 *)twl4030_rtc_reg_map;
528 	} else if (twl_class_is_6030()) {
529 		twl_rtc->class = TWL_6030;
530 		twl_rtc->reg_map = (u8 *)twl6030_rtc_reg_map;
531 	} else {
532 		dev_err(&pdev->dev, "TWL Class not supported.\n");
533 		return -EINVAL;
534 	}
535 
536 	ret = twl_rtc_read_u8(twl_rtc, &rd_reg, REG_RTC_STATUS_REG);
537 	if (ret < 0)
538 		return ret;
539 
540 	if (rd_reg & BIT_RTC_STATUS_REG_POWER_UP_M)
541 		dev_warn(&pdev->dev, "Power up reset detected.\n");
542 
543 	if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
544 		dev_warn(&pdev->dev, "Pending Alarm interrupt detected.\n");
545 
546 	/* Clear RTC Power up reset and pending alarm interrupts */
547 	ret = twl_rtc_write_u8(twl_rtc, rd_reg, REG_RTC_STATUS_REG);
548 	if (ret < 0)
549 		return ret;
550 
551 	if (twl_rtc->class == TWL_6030) {
552 		twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK,
553 			REG_INT_MSK_LINE_A);
554 		twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK,
555 			REG_INT_MSK_STS_A);
556 	}
557 
558 	ret = twl_rtc_write_u8(twl_rtc, BIT_RTC_CTRL_REG_STOP_RTC_M,
559 			       REG_RTC_CTRL_REG);
560 	if (ret < 0)
561 		return ret;
562 
563 	/* ensure interrupts are disabled, bootloaders can be strange */
564 	ret = twl_rtc_write_u8(twl_rtc, 0, REG_RTC_INTERRUPTS_REG);
565 	if (ret < 0)
566 		dev_warn(&pdev->dev, "unable to disable interrupt\n");
567 
568 	/* init cached IRQ enable bits */
569 	ret = twl_rtc_read_u8(twl_rtc, &twl_rtc->rtc_irq_bits,
570 			      REG_RTC_INTERRUPTS_REG);
571 	if (ret < 0)
572 		return ret;
573 
574 	platform_set_drvdata(pdev, twl_rtc);
575 	device_init_wakeup(&pdev->dev, 1);
576 
577 	twl_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
578 					&twl_rtc_ops, THIS_MODULE);
579 	if (IS_ERR(twl_rtc->rtc))
580 		return PTR_ERR(twl_rtc->rtc);
581 
582 	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
583 					twl_rtc_interrupt,
584 					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
585 					dev_name(&twl_rtc->rtc->dev), twl_rtc);
586 	if (ret < 0) {
587 		dev_err(&pdev->dev, "IRQ is not free.\n");
588 		return ret;
589 	}
590 
591 	memset(&nvmem_cfg, 0, sizeof(nvmem_cfg));
592 	nvmem_cfg.name = "twl-secured-";
593 	nvmem_cfg.type = NVMEM_TYPE_BATTERY_BACKED;
594 	nvmem_cfg.reg_read = twl_nvram_read;
595 	nvmem_cfg.reg_write = twl_nvram_write;
596 	nvmem_cfg.word_size = 1;
597 	nvmem_cfg.stride = 1;
598 	if (twl_class_is_4030()) {
599 		/* 20 bytes SECURED_REG area */
600 		nvmem_cfg.size = 20;
601 		nvmem_cfg.priv = (void *)TWL_MODULE_SECURED_REG;
602 		devm_rtc_nvmem_register(twl_rtc->rtc, &nvmem_cfg);
603 		/* 8 bytes BACKUP area */
604 		nvmem_cfg.name = "twl-backup-";
605 		nvmem_cfg.size = 8;
606 		nvmem_cfg.priv = (void *)TWL4030_MODULE_BACKUP;
607 		devm_rtc_nvmem_register(twl_rtc->rtc, &nvmem_cfg);
608 	} else {
609 		/* 8 bytes SECURED_REG area */
610 		nvmem_cfg.size = 8;
611 		nvmem_cfg.priv = (void *)TWL_MODULE_SECURED_REG;
612 		devm_rtc_nvmem_register(twl_rtc->rtc, &nvmem_cfg);
613 	}
614 
615 	return 0;
616 }
617 
618 /*
619  * Disable all TWL RTC module interrupts.
620  * Sets status flag to free.
621  */
twl_rtc_remove(struct platform_device * pdev)622 static void twl_rtc_remove(struct platform_device *pdev)
623 {
624 	struct twl_rtc *twl_rtc = platform_get_drvdata(pdev);
625 
626 	/* leave rtc running, but disable irqs */
627 	mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
628 	mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
629 	if (twl_rtc->class == TWL_6030) {
630 		twl6030_interrupt_mask(TWL6030_RTC_INT_MASK,
631 			REG_INT_MSK_LINE_A);
632 		twl6030_interrupt_mask(TWL6030_RTC_INT_MASK,
633 			REG_INT_MSK_STS_A);
634 	}
635 }
636 
twl_rtc_shutdown(struct platform_device * pdev)637 static void twl_rtc_shutdown(struct platform_device *pdev)
638 {
639 	struct twl_rtc *twl_rtc = platform_get_drvdata(pdev);
640 
641 	/* mask timer interrupts, but leave alarm interrupts on to enable
642 	   power-on when alarm is triggered */
643 	mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
644 }
645 
646 #ifdef CONFIG_PM_SLEEP
twl_rtc_suspend(struct device * dev)647 static int twl_rtc_suspend(struct device *dev)
648 {
649 	struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
650 
651 	twl_rtc->irqstat = twl_rtc->rtc_irq_bits;
652 
653 	mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
654 	return 0;
655 }
656 
twl_rtc_resume(struct device * dev)657 static int twl_rtc_resume(struct device *dev)
658 {
659 	struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
660 
661 	set_rtc_irq_bit(twl_rtc, twl_rtc->irqstat);
662 	return 0;
663 }
664 #endif
665 
666 static SIMPLE_DEV_PM_OPS(twl_rtc_pm_ops, twl_rtc_suspend, twl_rtc_resume);
667 
668 static const struct of_device_id twl_rtc_of_match[] = {
669 	{.compatible = "ti,twl4030-rtc", },
670 	{ },
671 };
672 MODULE_DEVICE_TABLE(of, twl_rtc_of_match);
673 
674 static struct platform_driver twl4030rtc_driver = {
675 	.probe		= twl_rtc_probe,
676 	.remove		= twl_rtc_remove,
677 	.shutdown	= twl_rtc_shutdown,
678 	.driver		= {
679 		.name		= "twl_rtc",
680 		.pm		= &twl_rtc_pm_ops,
681 		.of_match_table = twl_rtc_of_match,
682 	},
683 };
684 
685 module_platform_driver(twl4030rtc_driver);
686 
687 MODULE_AUTHOR("Texas Instruments, MontaVista Software");
688 MODULE_DESCRIPTION("TI TWL4030/TWL5030/TWL6030/TPS659x0 RTC driver");
689 MODULE_LICENSE("GPL");
690