1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Real time clock device driver for DA9063
4  * Copyright (C) 2013-2015  Dialog Semiconductor Ltd.
5  */
6 
7 #include <linux/delay.h>
8 #include <linux/init.h>
9 #include <linux/interrupt.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/platform_device.h>
14 #include <linux/pm_wakeirq.h>
15 #include <linux/regmap.h>
16 #include <linux/rtc.h>
17 #include <linux/slab.h>
18 
19 #include <linux/mfd/da9062/registers.h>
20 #include <linux/mfd/da9063/registers.h>
21 #include <linux/mfd/da9063/core.h>
22 
23 #define YEARS_TO_DA9063(year)		((year) - 100)
24 #define MONTHS_TO_DA9063(month)		((month) + 1)
25 #define YEARS_FROM_DA9063(year)		((year) + 100)
26 #define MONTHS_FROM_DA9063(month)	((month) - 1)
27 
28 enum {
29 	RTC_SEC	= 0,
30 	RTC_MIN	= 1,
31 	RTC_HOUR = 2,
32 	RTC_DAY	= 3,
33 	RTC_MONTH = 4,
34 	RTC_YEAR = 5,
35 	RTC_DATA_LEN
36 };
37 
38 struct da9063_compatible_rtc_regmap {
39 	/* REGS */
40 	int rtc_enable_reg;
41 	int rtc_enable_32k_crystal_reg;
42 	int rtc_alarm_secs_reg;
43 	int rtc_alarm_year_reg;
44 	int rtc_count_secs_reg;
45 	int rtc_count_year_reg;
46 	int rtc_event_reg;
47 	/* MASKS */
48 	int rtc_enable_mask;
49 	int rtc_crystal_mask;
50 	int rtc_event_alarm_mask;
51 	int rtc_alarm_on_mask;
52 	int rtc_alarm_status_mask;
53 	int rtc_tick_on_mask;
54 	int rtc_ready_to_read_mask;
55 	int rtc_count_sec_mask;
56 	int rtc_count_min_mask;
57 	int rtc_count_hour_mask;
58 	int rtc_count_day_mask;
59 	int rtc_count_month_mask;
60 	int rtc_count_year_mask;
61 	/* ALARM CONFIG */
62 	int rtc_data_start;
63 	int rtc_alarm_len;
64 };
65 
66 struct da9063_compatible_rtc {
67 	struct rtc_device *rtc_dev;
68 	struct rtc_time alarm_time;
69 	struct regmap *regmap;
70 	const struct da9063_compatible_rtc_regmap *config;
71 	bool rtc_sync;
72 };
73 
74 static const struct da9063_compatible_rtc_regmap da9063_ad_regs = {
75 	/* REGS */
76 	.rtc_enable_reg             = DA9063_REG_CONTROL_E,
77 	.rtc_alarm_secs_reg         = DA9063_AD_REG_ALARM_MI,
78 	.rtc_alarm_year_reg         = DA9063_AD_REG_ALARM_Y,
79 	.rtc_count_secs_reg         = DA9063_REG_COUNT_S,
80 	.rtc_count_year_reg         = DA9063_REG_COUNT_Y,
81 	.rtc_event_reg              = DA9063_REG_EVENT_A,
82 	/* MASKS */
83 	.rtc_enable_mask            = DA9063_RTC_EN,
84 	.rtc_crystal_mask           = DA9063_CRYSTAL,
85 	.rtc_enable_32k_crystal_reg = DA9063_REG_EN_32K,
86 	.rtc_event_alarm_mask       = DA9063_E_ALARM,
87 	.rtc_alarm_on_mask          = DA9063_ALARM_ON,
88 	.rtc_alarm_status_mask      = DA9063_ALARM_STATUS_ALARM |
89 				      DA9063_ALARM_STATUS_TICK,
90 	.rtc_tick_on_mask           = DA9063_TICK_ON,
91 	.rtc_ready_to_read_mask     = DA9063_RTC_READ,
92 	.rtc_count_sec_mask         = DA9063_COUNT_SEC_MASK,
93 	.rtc_count_min_mask         = DA9063_COUNT_MIN_MASK,
94 	.rtc_count_hour_mask        = DA9063_COUNT_HOUR_MASK,
95 	.rtc_count_day_mask         = DA9063_COUNT_DAY_MASK,
96 	.rtc_count_month_mask       = DA9063_COUNT_MONTH_MASK,
97 	.rtc_count_year_mask        = DA9063_COUNT_YEAR_MASK,
98 	/* ALARM CONFIG */
99 	.rtc_data_start             = RTC_MIN,
100 	.rtc_alarm_len              = RTC_DATA_LEN - 1,
101 };
102 
103 static const struct da9063_compatible_rtc_regmap da9063_bb_regs = {
104 	/* REGS */
105 	.rtc_enable_reg             = DA9063_REG_CONTROL_E,
106 	.rtc_alarm_secs_reg         = DA9063_BB_REG_ALARM_S,
107 	.rtc_alarm_year_reg         = DA9063_BB_REG_ALARM_Y,
108 	.rtc_count_secs_reg         = DA9063_REG_COUNT_S,
109 	.rtc_count_year_reg         = DA9063_REG_COUNT_Y,
110 	.rtc_event_reg              = DA9063_REG_EVENT_A,
111 	/* MASKS */
112 	.rtc_enable_mask            = DA9063_RTC_EN,
113 	.rtc_crystal_mask           = DA9063_CRYSTAL,
114 	.rtc_enable_32k_crystal_reg = DA9063_REG_EN_32K,
115 	.rtc_event_alarm_mask       = DA9063_E_ALARM,
116 	.rtc_alarm_on_mask          = DA9063_ALARM_ON,
117 	.rtc_alarm_status_mask      = DA9063_ALARM_STATUS_ALARM |
118 				      DA9063_ALARM_STATUS_TICK,
119 	.rtc_tick_on_mask           = DA9063_TICK_ON,
120 	.rtc_ready_to_read_mask     = DA9063_RTC_READ,
121 	.rtc_count_sec_mask         = DA9063_COUNT_SEC_MASK,
122 	.rtc_count_min_mask         = DA9063_COUNT_MIN_MASK,
123 	.rtc_count_hour_mask        = DA9063_COUNT_HOUR_MASK,
124 	.rtc_count_day_mask         = DA9063_COUNT_DAY_MASK,
125 	.rtc_count_month_mask       = DA9063_COUNT_MONTH_MASK,
126 	.rtc_count_year_mask        = DA9063_COUNT_YEAR_MASK,
127 	/* ALARM CONFIG */
128 	.rtc_data_start             = RTC_SEC,
129 	.rtc_alarm_len              = RTC_DATA_LEN,
130 };
131 
132 static const struct da9063_compatible_rtc_regmap da9062_aa_regs = {
133 	/* REGS */
134 	.rtc_enable_reg             = DA9062AA_CONTROL_E,
135 	.rtc_alarm_secs_reg         = DA9062AA_ALARM_S,
136 	.rtc_alarm_year_reg         = DA9062AA_ALARM_Y,
137 	.rtc_count_secs_reg         = DA9062AA_COUNT_S,
138 	.rtc_count_year_reg         = DA9062AA_COUNT_Y,
139 	.rtc_event_reg              = DA9062AA_EVENT_A,
140 	/* MASKS */
141 	.rtc_enable_mask            = DA9062AA_RTC_EN_MASK,
142 	.rtc_crystal_mask           = DA9062AA_CRYSTAL_MASK,
143 	.rtc_enable_32k_crystal_reg = DA9062AA_EN_32K,
144 	.rtc_event_alarm_mask       = DA9062AA_M_ALARM_MASK,
145 	.rtc_alarm_on_mask          = DA9062AA_ALARM_ON_MASK,
146 	.rtc_alarm_status_mask      = (0x02 << 6),
147 	.rtc_tick_on_mask           = DA9062AA_TICK_ON_MASK,
148 	.rtc_ready_to_read_mask     = DA9062AA_RTC_READ_MASK,
149 	.rtc_count_sec_mask         = DA9062AA_COUNT_SEC_MASK,
150 	.rtc_count_min_mask         = DA9062AA_COUNT_MIN_MASK,
151 	.rtc_count_hour_mask        = DA9062AA_COUNT_HOUR_MASK,
152 	.rtc_count_day_mask         = DA9062AA_COUNT_DAY_MASK,
153 	.rtc_count_month_mask       = DA9062AA_COUNT_MONTH_MASK,
154 	.rtc_count_year_mask        = DA9062AA_COUNT_YEAR_MASK,
155 	/* ALARM CONFIG */
156 	.rtc_data_start             = RTC_SEC,
157 	.rtc_alarm_len              = RTC_DATA_LEN,
158 };
159 
160 static const struct of_device_id da9063_compatible_reg_id_table[] = {
161 	{ .compatible = "dlg,da9063-rtc", .data = &da9063_bb_regs },
162 	{ .compatible = "dlg,da9062-rtc", .data = &da9062_aa_regs },
163 	{ },
164 };
165 MODULE_DEVICE_TABLE(of, da9063_compatible_reg_id_table);
166 
167 static void da9063_data_to_tm(u8 *data, struct rtc_time *tm,
168 			      struct da9063_compatible_rtc *rtc)
169 {
170 	const struct da9063_compatible_rtc_regmap *config = rtc->config;
171 
172 	tm->tm_sec  = data[RTC_SEC]  & config->rtc_count_sec_mask;
173 	tm->tm_min  = data[RTC_MIN]  & config->rtc_count_min_mask;
174 	tm->tm_hour = data[RTC_HOUR] & config->rtc_count_hour_mask;
175 	tm->tm_mday = data[RTC_DAY]  & config->rtc_count_day_mask;
176 	tm->tm_mon  = MONTHS_FROM_DA9063(data[RTC_MONTH] &
177 					 config->rtc_count_month_mask);
178 	tm->tm_year = YEARS_FROM_DA9063(data[RTC_YEAR] &
179 					config->rtc_count_year_mask);
180 }
181 
182 static void da9063_tm_to_data(struct rtc_time *tm, u8 *data,
183 			      struct da9063_compatible_rtc *rtc)
184 {
185 	const struct da9063_compatible_rtc_regmap *config = rtc->config;
186 
187 	data[RTC_SEC]   = tm->tm_sec & config->rtc_count_sec_mask;
188 	data[RTC_MIN]   = tm->tm_min & config->rtc_count_min_mask;
189 	data[RTC_HOUR]  = tm->tm_hour & config->rtc_count_hour_mask;
190 	data[RTC_DAY]   = tm->tm_mday & config->rtc_count_day_mask;
191 	data[RTC_MONTH] = MONTHS_TO_DA9063(tm->tm_mon) &
192 				config->rtc_count_month_mask;
193 	data[RTC_YEAR]  = YEARS_TO_DA9063(tm->tm_year) &
194 				config->rtc_count_year_mask;
195 }
196 
197 static int da9063_rtc_alarm_irq_enable(struct device *dev,
198 				       unsigned int enabled)
199 {
200 	struct da9063_compatible_rtc *rtc = dev_get_drvdata(dev);
201 	const struct da9063_compatible_rtc_regmap *config = rtc->config;
202 	u8 set_bit = enabled ? config->rtc_alarm_on_mask : 0;
203 
204 	return regmap_update_bits(rtc->regmap,
205 				  config->rtc_alarm_year_reg,
206 				  config->rtc_alarm_on_mask,
207 				  set_bit);
208 }
209 
210 static int da9063_rtc_read_time(struct device *dev, struct rtc_time *tm)
211 {
212 	struct da9063_compatible_rtc *rtc = dev_get_drvdata(dev);
213 	const struct da9063_compatible_rtc_regmap *config = rtc->config;
214 	unsigned long tm_secs;
215 	unsigned long al_secs;
216 	u8 data[RTC_DATA_LEN];
217 	int ret;
218 
219 	ret = regmap_bulk_read(rtc->regmap,
220 			       config->rtc_count_secs_reg,
221 			       data, RTC_DATA_LEN);
222 	if (ret < 0) {
223 		dev_err(dev, "Failed to read RTC time data: %d\n", ret);
224 		return ret;
225 	}
226 
227 	if (!(data[RTC_SEC] & config->rtc_ready_to_read_mask)) {
228 		dev_dbg(dev, "RTC not yet ready to be read by the host\n");
229 		return -EINVAL;
230 	}
231 
232 	da9063_data_to_tm(data, tm, rtc);
233 
234 	tm_secs = rtc_tm_to_time64(tm);
235 	al_secs = rtc_tm_to_time64(&rtc->alarm_time);
236 
237 	/* handle the rtc synchronisation delay */
238 	if (rtc->rtc_sync && al_secs - tm_secs == 1)
239 		memcpy(tm, &rtc->alarm_time, sizeof(struct rtc_time));
240 	else
241 		rtc->rtc_sync = false;
242 
243 	return 0;
244 }
245 
246 static int da9063_rtc_set_time(struct device *dev, struct rtc_time *tm)
247 {
248 	struct da9063_compatible_rtc *rtc = dev_get_drvdata(dev);
249 	const struct da9063_compatible_rtc_regmap *config = rtc->config;
250 	u8 data[RTC_DATA_LEN];
251 	int ret;
252 
253 	da9063_tm_to_data(tm, data, rtc);
254 	ret = regmap_bulk_write(rtc->regmap,
255 				config->rtc_count_secs_reg,
256 				data, RTC_DATA_LEN);
257 	if (ret < 0)
258 		dev_err(dev, "Failed to set RTC time data: %d\n", ret);
259 
260 	return ret;
261 }
262 
263 static int da9063_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
264 {
265 	struct da9063_compatible_rtc *rtc = dev_get_drvdata(dev);
266 	const struct da9063_compatible_rtc_regmap *config = rtc->config;
267 	u8 data[RTC_DATA_LEN];
268 	int ret;
269 	unsigned int val;
270 
271 	data[RTC_SEC] = 0;
272 	ret = regmap_bulk_read(rtc->regmap,
273 			       config->rtc_alarm_secs_reg,
274 			       &data[config->rtc_data_start],
275 			       config->rtc_alarm_len);
276 	if (ret < 0)
277 		return ret;
278 
279 	da9063_data_to_tm(data, &alrm->time, rtc);
280 
281 	alrm->enabled = !!(data[RTC_YEAR] & config->rtc_alarm_on_mask);
282 
283 	ret = regmap_read(rtc->regmap,
284 			  config->rtc_event_reg,
285 			  &val);
286 	if (ret < 0)
287 		return ret;
288 
289 	if (val & config->rtc_event_alarm_mask)
290 		alrm->pending = 1;
291 	else
292 		alrm->pending = 0;
293 
294 	return 0;
295 }
296 
297 static int da9063_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
298 {
299 	struct da9063_compatible_rtc *rtc = dev_get_drvdata(dev);
300 	const struct da9063_compatible_rtc_regmap *config = rtc->config;
301 	u8 data[RTC_DATA_LEN];
302 	int ret;
303 
304 	da9063_tm_to_data(&alrm->time, data, rtc);
305 
306 	ret = da9063_rtc_alarm_irq_enable(dev, 0);
307 	if (ret < 0) {
308 		dev_err(dev, "Failed to stop alarm: %d\n", ret);
309 		return ret;
310 	}
311 
312 	ret = regmap_bulk_write(rtc->regmap,
313 				config->rtc_alarm_secs_reg,
314 				&data[config->rtc_data_start],
315 				config->rtc_alarm_len);
316 	if (ret < 0) {
317 		dev_err(dev, "Failed to write alarm: %d\n", ret);
318 		return ret;
319 	}
320 
321 	da9063_data_to_tm(data, &rtc->alarm_time, rtc);
322 
323 	if (alrm->enabled) {
324 		ret = da9063_rtc_alarm_irq_enable(dev, 1);
325 		if (ret < 0) {
326 			dev_err(dev, "Failed to start alarm: %d\n", ret);
327 			return ret;
328 		}
329 	}
330 
331 	return ret;
332 }
333 
334 static irqreturn_t da9063_alarm_event(int irq, void *data)
335 {
336 	struct da9063_compatible_rtc *rtc = data;
337 	const struct da9063_compatible_rtc_regmap *config = rtc->config;
338 
339 	regmap_update_bits(rtc->regmap,
340 			   config->rtc_alarm_year_reg,
341 			   config->rtc_alarm_on_mask,
342 			   0);
343 
344 	rtc->rtc_sync = true;
345 	rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
346 
347 	return IRQ_HANDLED;
348 }
349 
350 static const struct rtc_class_ops da9063_rtc_ops = {
351 	.read_time = da9063_rtc_read_time,
352 	.set_time = da9063_rtc_set_time,
353 	.read_alarm = da9063_rtc_read_alarm,
354 	.set_alarm = da9063_rtc_set_alarm,
355 	.alarm_irq_enable = da9063_rtc_alarm_irq_enable,
356 };
357 
358 static int da9063_rtc_probe(struct platform_device *pdev)
359 {
360 	struct da9063_compatible_rtc *rtc;
361 	const struct da9063_compatible_rtc_regmap *config;
362 	int irq_alarm;
363 	u8 data[RTC_DATA_LEN];
364 	int ret;
365 
366 	if (!pdev->dev.of_node)
367 		return -ENXIO;
368 
369 	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
370 	if (!rtc)
371 		return -ENOMEM;
372 
373 	rtc->config = device_get_match_data(&pdev->dev);
374 	if (of_device_is_compatible(pdev->dev.of_node, "dlg,da9063-rtc")) {
375 		struct da9063 *chip = dev_get_drvdata(pdev->dev.parent);
376 
377 		if (chip->variant_code == PMIC_DA9063_AD)
378 			rtc->config = &da9063_ad_regs;
379 	}
380 
381 	rtc->regmap = dev_get_regmap(pdev->dev.parent, NULL);
382 	if (!rtc->regmap) {
383 		dev_warn(&pdev->dev, "Parent regmap unavailable.\n");
384 		return -ENXIO;
385 	}
386 
387 	config = rtc->config;
388 	ret = regmap_update_bits(rtc->regmap,
389 				 config->rtc_enable_reg,
390 				 config->rtc_enable_mask,
391 				 config->rtc_enable_mask);
392 	if (ret < 0)
393 		return dev_err_probe(&pdev->dev, ret, "Failed to enable RTC\n");
394 
395 	ret = regmap_update_bits(rtc->regmap,
396 				 config->rtc_enable_32k_crystal_reg,
397 				 config->rtc_crystal_mask,
398 				 config->rtc_crystal_mask);
399 	if (ret < 0)
400 		return dev_err_probe(&pdev->dev, ret,
401 				     "Failed to run 32kHz oscillator\n");
402 
403 	ret = regmap_update_bits(rtc->regmap,
404 				 config->rtc_alarm_secs_reg,
405 				 config->rtc_alarm_status_mask,
406 				 0);
407 	if (ret < 0)
408 		return dev_err_probe(&pdev->dev, ret,
409 				     "Failed to access RTC alarm register\n");
410 
411 	ret = regmap_update_bits(rtc->regmap,
412 				 config->rtc_alarm_secs_reg,
413 				 DA9063_ALARM_STATUS_ALARM,
414 				 DA9063_ALARM_STATUS_ALARM);
415 	if (ret < 0)
416 		return dev_err_probe(&pdev->dev, ret,
417 				     "Failed to access RTC alarm register\n");
418 
419 	ret = regmap_update_bits(rtc->regmap,
420 				 config->rtc_alarm_year_reg,
421 				 config->rtc_tick_on_mask,
422 				 0);
423 	if (ret < 0)
424 		return dev_err_probe(&pdev->dev, ret,
425 				     "Failed to disable TICKs\n");
426 
427 	data[RTC_SEC] = 0;
428 	ret = regmap_bulk_read(rtc->regmap,
429 			       config->rtc_alarm_secs_reg,
430 			       &data[config->rtc_data_start],
431 			       config->rtc_alarm_len);
432 	if (ret < 0)
433 		return dev_err_probe(&pdev->dev, ret,
434 				     "Failed to read initial alarm data\n");
435 
436 	platform_set_drvdata(pdev, rtc);
437 
438 	rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
439 	if (IS_ERR(rtc->rtc_dev))
440 		return PTR_ERR(rtc->rtc_dev);
441 
442 	rtc->rtc_dev->ops = &da9063_rtc_ops;
443 	rtc->rtc_dev->range_min = RTC_TIMESTAMP_BEGIN_2000;
444 	rtc->rtc_dev->range_max = RTC_TIMESTAMP_END_2063;
445 
446 	da9063_data_to_tm(data, &rtc->alarm_time, rtc);
447 	rtc->rtc_sync = false;
448 
449 	if (config->rtc_data_start != RTC_SEC) {
450 		set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->rtc_dev->features);
451 		/*
452 		 * TODO: some models have alarms on a minute boundary but still
453 		 * support real hardware interrupts.
454 		 */
455 		clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->rtc_dev->features);
456 	}
457 
458 	irq_alarm = platform_get_irq_byname_optional(pdev, "ALARM");
459 	if (irq_alarm >= 0) {
460 		ret = devm_request_threaded_irq(&pdev->dev, irq_alarm, NULL,
461 						da9063_alarm_event,
462 						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
463 						"ALARM", rtc);
464 		if (ret)
465 			dev_err(&pdev->dev,
466 				"Failed to request ALARM IRQ %d: %d\n",
467 				irq_alarm, ret);
468 
469 		ret = dev_pm_set_wake_irq(&pdev->dev, irq_alarm);
470 		if (ret)
471 			dev_warn(&pdev->dev,
472 				 "Failed to set IRQ %d as a wake IRQ: %d\n",
473 				 irq_alarm, ret);
474 
475 		device_init_wakeup(&pdev->dev, true);
476 	}  else if (irq_alarm != -ENXIO) {
477 		return irq_alarm;
478 	} else {
479 		clear_bit(RTC_FEATURE_ALARM, rtc->rtc_dev->features);
480 	}
481 
482 	return devm_rtc_register_device(rtc->rtc_dev);
483 }
484 
485 static struct platform_driver da9063_rtc_driver = {
486 	.probe		= da9063_rtc_probe,
487 	.driver		= {
488 		.name	= DA9063_DRVNAME_RTC,
489 		.of_match_table = da9063_compatible_reg_id_table,
490 	},
491 };
492 
493 module_platform_driver(da9063_rtc_driver);
494 
495 MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
496 MODULE_DESCRIPTION("Real time clock device driver for Dialog DA9063");
497 MODULE_LICENSE("GPL");
498