xref: /openbmc/linux/drivers/rtc/rtc-da9063.c (revision fb574682)
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/regmap.h>
15 #include <linux/rtc.h>
16 #include <linux/slab.h>
17 
18 #include <linux/mfd/da9062/registers.h>
19 #include <linux/mfd/da9063/registers.h>
20 #include <linux/mfd/da9063/core.h>
21 
22 #define YEARS_TO_DA9063(year)		((year) - 100)
23 #define MONTHS_TO_DA9063(month)		((month) + 1)
24 #define YEARS_FROM_DA9063(year)		((year) + 100)
25 #define MONTHS_FROM_DA9063(month)	((month) - 1)
26 
27 enum {
28 	RTC_SEC	= 0,
29 	RTC_MIN	= 1,
30 	RTC_HOUR = 2,
31 	RTC_DAY	= 3,
32 	RTC_MONTH = 4,
33 	RTC_YEAR = 5,
34 	RTC_DATA_LEN
35 };
36 
37 struct da9063_compatible_rtc_regmap {
38 	/* REGS */
39 	int rtc_enable_reg;
40 	int rtc_enable_32k_crystal_reg;
41 	int rtc_alarm_secs_reg;
42 	int rtc_alarm_year_reg;
43 	int rtc_count_secs_reg;
44 	int rtc_count_year_reg;
45 	int rtc_event_reg;
46 	/* MASKS */
47 	int rtc_enable_mask;
48 	int rtc_crystal_mask;
49 	int rtc_event_alarm_mask;
50 	int rtc_alarm_on_mask;
51 	int rtc_alarm_status_mask;
52 	int rtc_tick_on_mask;
53 	int rtc_ready_to_read_mask;
54 	int rtc_count_sec_mask;
55 	int rtc_count_min_mask;
56 	int rtc_count_hour_mask;
57 	int rtc_count_day_mask;
58 	int rtc_count_month_mask;
59 	int rtc_count_year_mask;
60 	/* ALARM CONFIG */
61 	int rtc_data_start;
62 	int rtc_alarm_len;
63 };
64 
65 struct da9063_compatible_rtc {
66 	struct rtc_device *rtc_dev;
67 	struct rtc_time alarm_time;
68 	struct regmap *regmap;
69 	const struct da9063_compatible_rtc_regmap *config;
70 	bool rtc_sync;
71 };
72 
73 static const struct da9063_compatible_rtc_regmap da9063_ad_regs = {
74 	/* REGS */
75 	.rtc_enable_reg             = DA9063_REG_CONTROL_E,
76 	.rtc_alarm_secs_reg         = DA9063_AD_REG_ALARM_MI,
77 	.rtc_alarm_year_reg         = DA9063_AD_REG_ALARM_Y,
78 	.rtc_count_secs_reg         = DA9063_REG_COUNT_S,
79 	.rtc_count_year_reg         = DA9063_REG_COUNT_Y,
80 	.rtc_event_reg              = DA9063_REG_EVENT_A,
81 	/* MASKS */
82 	.rtc_enable_mask            = DA9063_RTC_EN,
83 	.rtc_crystal_mask           = DA9063_CRYSTAL,
84 	.rtc_enable_32k_crystal_reg = DA9063_REG_EN_32K,
85 	.rtc_event_alarm_mask       = DA9063_E_ALARM,
86 	.rtc_alarm_on_mask          = DA9063_ALARM_ON,
87 	.rtc_alarm_status_mask      = DA9063_ALARM_STATUS_ALARM |
88 				      DA9063_ALARM_STATUS_TICK,
89 	.rtc_tick_on_mask           = DA9063_TICK_ON,
90 	.rtc_ready_to_read_mask     = DA9063_RTC_READ,
91 	.rtc_count_sec_mask         = DA9063_COUNT_SEC_MASK,
92 	.rtc_count_min_mask         = DA9063_COUNT_MIN_MASK,
93 	.rtc_count_hour_mask        = DA9063_COUNT_HOUR_MASK,
94 	.rtc_count_day_mask         = DA9063_COUNT_DAY_MASK,
95 	.rtc_count_month_mask       = DA9063_COUNT_MONTH_MASK,
96 	.rtc_count_year_mask        = DA9063_COUNT_YEAR_MASK,
97 	/* ALARM CONFIG */
98 	.rtc_data_start             = RTC_MIN,
99 	.rtc_alarm_len              = RTC_DATA_LEN - 1,
100 };
101 
102 static const struct da9063_compatible_rtc_regmap da9063_bb_regs = {
103 	/* REGS */
104 	.rtc_enable_reg             = DA9063_REG_CONTROL_E,
105 	.rtc_alarm_secs_reg         = DA9063_BB_REG_ALARM_S,
106 	.rtc_alarm_year_reg         = DA9063_BB_REG_ALARM_Y,
107 	.rtc_count_secs_reg         = DA9063_REG_COUNT_S,
108 	.rtc_count_year_reg         = DA9063_REG_COUNT_Y,
109 	.rtc_event_reg              = DA9063_REG_EVENT_A,
110 	/* MASKS */
111 	.rtc_enable_mask            = DA9063_RTC_EN,
112 	.rtc_crystal_mask           = DA9063_CRYSTAL,
113 	.rtc_enable_32k_crystal_reg = DA9063_REG_EN_32K,
114 	.rtc_event_alarm_mask       = DA9063_E_ALARM,
115 	.rtc_alarm_on_mask          = DA9063_ALARM_ON,
116 	.rtc_alarm_status_mask      = DA9063_ALARM_STATUS_ALARM |
117 				      DA9063_ALARM_STATUS_TICK,
118 	.rtc_tick_on_mask           = DA9063_TICK_ON,
119 	.rtc_ready_to_read_mask     = DA9063_RTC_READ,
120 	.rtc_count_sec_mask         = DA9063_COUNT_SEC_MASK,
121 	.rtc_count_min_mask         = DA9063_COUNT_MIN_MASK,
122 	.rtc_count_hour_mask        = DA9063_COUNT_HOUR_MASK,
123 	.rtc_count_day_mask         = DA9063_COUNT_DAY_MASK,
124 	.rtc_count_month_mask       = DA9063_COUNT_MONTH_MASK,
125 	.rtc_count_year_mask        = DA9063_COUNT_YEAR_MASK,
126 	/* ALARM CONFIG */
127 	.rtc_data_start             = RTC_SEC,
128 	.rtc_alarm_len              = RTC_DATA_LEN,
129 };
130 
131 static const struct da9063_compatible_rtc_regmap da9062_aa_regs = {
132 	/* REGS */
133 	.rtc_enable_reg             = DA9062AA_CONTROL_E,
134 	.rtc_alarm_secs_reg         = DA9062AA_ALARM_S,
135 	.rtc_alarm_year_reg         = DA9062AA_ALARM_Y,
136 	.rtc_count_secs_reg         = DA9062AA_COUNT_S,
137 	.rtc_count_year_reg         = DA9062AA_COUNT_Y,
138 	.rtc_event_reg              = DA9062AA_EVENT_A,
139 	/* MASKS */
140 	.rtc_enable_mask            = DA9062AA_RTC_EN_MASK,
141 	.rtc_crystal_mask           = DA9062AA_CRYSTAL_MASK,
142 	.rtc_enable_32k_crystal_reg = DA9062AA_EN_32K,
143 	.rtc_event_alarm_mask       = DA9062AA_M_ALARM_MASK,
144 	.rtc_alarm_on_mask          = DA9062AA_ALARM_ON_MASK,
145 	.rtc_alarm_status_mask      = (0x02 << 6),
146 	.rtc_tick_on_mask           = DA9062AA_TICK_ON_MASK,
147 	.rtc_ready_to_read_mask     = DA9062AA_RTC_READ_MASK,
148 	.rtc_count_sec_mask         = DA9062AA_COUNT_SEC_MASK,
149 	.rtc_count_min_mask         = DA9062AA_COUNT_MIN_MASK,
150 	.rtc_count_hour_mask        = DA9062AA_COUNT_HOUR_MASK,
151 	.rtc_count_day_mask         = DA9062AA_COUNT_DAY_MASK,
152 	.rtc_count_month_mask       = DA9062AA_COUNT_MONTH_MASK,
153 	.rtc_count_year_mask        = DA9062AA_COUNT_YEAR_MASK,
154 	/* ALARM CONFIG */
155 	.rtc_data_start             = RTC_SEC,
156 	.rtc_alarm_len              = RTC_DATA_LEN,
157 };
158 
159 static const struct of_device_id da9063_compatible_reg_id_table[] = {
160 	{ .compatible = "dlg,da9063-rtc", .data = &da9063_bb_regs },
161 	{ .compatible = "dlg,da9062-rtc", .data = &da9062_aa_regs },
162 	{ },
163 };
164 MODULE_DEVICE_TABLE(of, da9063_compatible_reg_id_table);
165 
166 static void da9063_data_to_tm(u8 *data, struct rtc_time *tm,
167 			      struct da9063_compatible_rtc *rtc)
168 {
169 	const struct da9063_compatible_rtc_regmap *config = rtc->config;
170 
171 	tm->tm_sec  = data[RTC_SEC]  & config->rtc_count_sec_mask;
172 	tm->tm_min  = data[RTC_MIN]  & config->rtc_count_min_mask;
173 	tm->tm_hour = data[RTC_HOUR] & config->rtc_count_hour_mask;
174 	tm->tm_mday = data[RTC_DAY]  & config->rtc_count_day_mask;
175 	tm->tm_mon  = MONTHS_FROM_DA9063(data[RTC_MONTH] &
176 					 config->rtc_count_month_mask);
177 	tm->tm_year = YEARS_FROM_DA9063(data[RTC_YEAR] &
178 					config->rtc_count_year_mask);
179 }
180 
181 static void da9063_tm_to_data(struct rtc_time *tm, u8 *data,
182 			      struct da9063_compatible_rtc *rtc)
183 {
184 	const struct da9063_compatible_rtc_regmap *config = rtc->config;
185 
186 	data[RTC_SEC]   = tm->tm_sec & config->rtc_count_sec_mask;
187 	data[RTC_MIN]   = tm->tm_min & config->rtc_count_min_mask;
188 	data[RTC_HOUR]  = tm->tm_hour & config->rtc_count_hour_mask;
189 	data[RTC_DAY]   = tm->tm_mday & config->rtc_count_day_mask;
190 	data[RTC_MONTH] = MONTHS_TO_DA9063(tm->tm_mon) &
191 				config->rtc_count_month_mask;
192 	data[RTC_YEAR]  = YEARS_TO_DA9063(tm->tm_year) &
193 				config->rtc_count_year_mask;
194 }
195 
196 static int da9063_rtc_stop_alarm(struct device *dev)
197 {
198 	struct da9063_compatible_rtc *rtc = dev_get_drvdata(dev);
199 	const struct da9063_compatible_rtc_regmap *config = rtc->config;
200 
201 	return regmap_update_bits(rtc->regmap,
202 				  config->rtc_alarm_year_reg,
203 				  config->rtc_alarm_on_mask,
204 				  0);
205 }
206 
207 static int da9063_rtc_start_alarm(struct device *dev)
208 {
209 	struct da9063_compatible_rtc *rtc = dev_get_drvdata(dev);
210 	const struct da9063_compatible_rtc_regmap *config = rtc->config;
211 
212 	return regmap_update_bits(rtc->regmap,
213 				  config->rtc_alarm_year_reg,
214 				  config->rtc_alarm_on_mask,
215 				  config->rtc_alarm_on_mask);
216 }
217 
218 static int da9063_rtc_read_time(struct device *dev, struct rtc_time *tm)
219 {
220 	struct da9063_compatible_rtc *rtc = dev_get_drvdata(dev);
221 	const struct da9063_compatible_rtc_regmap *config = rtc->config;
222 	unsigned long tm_secs;
223 	unsigned long al_secs;
224 	u8 data[RTC_DATA_LEN];
225 	int ret;
226 
227 	ret = regmap_bulk_read(rtc->regmap,
228 			       config->rtc_count_secs_reg,
229 			       data, RTC_DATA_LEN);
230 	if (ret < 0) {
231 		dev_err(dev, "Failed to read RTC time data: %d\n", ret);
232 		return ret;
233 	}
234 
235 	if (!(data[RTC_SEC] & config->rtc_ready_to_read_mask)) {
236 		dev_dbg(dev, "RTC not yet ready to be read by the host\n");
237 		return -EINVAL;
238 	}
239 
240 	da9063_data_to_tm(data, tm, rtc);
241 
242 	tm_secs = rtc_tm_to_time64(tm);
243 	al_secs = rtc_tm_to_time64(&rtc->alarm_time);
244 
245 	/* handle the rtc synchronisation delay */
246 	if (rtc->rtc_sync == true && al_secs - tm_secs == 1)
247 		memcpy(tm, &rtc->alarm_time, sizeof(struct rtc_time));
248 	else
249 		rtc->rtc_sync = false;
250 
251 	return 0;
252 }
253 
254 static int da9063_rtc_set_time(struct device *dev, struct rtc_time *tm)
255 {
256 	struct da9063_compatible_rtc *rtc = dev_get_drvdata(dev);
257 	const struct da9063_compatible_rtc_regmap *config = rtc->config;
258 	u8 data[RTC_DATA_LEN];
259 	int ret;
260 
261 	da9063_tm_to_data(tm, data, rtc);
262 	ret = regmap_bulk_write(rtc->regmap,
263 				config->rtc_count_secs_reg,
264 				data, RTC_DATA_LEN);
265 	if (ret < 0)
266 		dev_err(dev, "Failed to set RTC time data: %d\n", ret);
267 
268 	return ret;
269 }
270 
271 static int da9063_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
272 {
273 	struct da9063_compatible_rtc *rtc = dev_get_drvdata(dev);
274 	const struct da9063_compatible_rtc_regmap *config = rtc->config;
275 	u8 data[RTC_DATA_LEN];
276 	int ret;
277 	unsigned int val;
278 
279 	data[RTC_SEC] = 0;
280 	ret = regmap_bulk_read(rtc->regmap,
281 			       config->rtc_alarm_secs_reg,
282 			       &data[config->rtc_data_start],
283 			       config->rtc_alarm_len);
284 	if (ret < 0)
285 		return ret;
286 
287 	da9063_data_to_tm(data, &alrm->time, rtc);
288 
289 	alrm->enabled = !!(data[RTC_YEAR] & config->rtc_alarm_on_mask);
290 
291 	ret = regmap_read(rtc->regmap,
292 			  config->rtc_event_reg,
293 			  &val);
294 	if (ret < 0)
295 		return ret;
296 
297 	if (val & config->rtc_event_alarm_mask)
298 		alrm->pending = 1;
299 	else
300 		alrm->pending = 0;
301 
302 	return 0;
303 }
304 
305 static int da9063_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
306 {
307 	struct da9063_compatible_rtc *rtc = dev_get_drvdata(dev);
308 	const struct da9063_compatible_rtc_regmap *config = rtc->config;
309 	u8 data[RTC_DATA_LEN];
310 	int ret;
311 
312 	da9063_tm_to_data(&alrm->time, data, rtc);
313 
314 	ret = da9063_rtc_stop_alarm(dev);
315 	if (ret < 0) {
316 		dev_err(dev, "Failed to stop alarm: %d\n", ret);
317 		return ret;
318 	}
319 
320 	ret = regmap_bulk_write(rtc->regmap,
321 				config->rtc_alarm_secs_reg,
322 				&data[config->rtc_data_start],
323 				config->rtc_alarm_len);
324 	if (ret < 0) {
325 		dev_err(dev, "Failed to write alarm: %d\n", ret);
326 		return ret;
327 	}
328 
329 	da9063_data_to_tm(data, &rtc->alarm_time, rtc);
330 
331 	if (alrm->enabled) {
332 		ret = da9063_rtc_start_alarm(dev);
333 		if (ret < 0) {
334 			dev_err(dev, "Failed to start alarm: %d\n", ret);
335 			return ret;
336 		}
337 	}
338 
339 	return ret;
340 }
341 
342 static int da9063_rtc_alarm_irq_enable(struct device *dev,
343 				       unsigned int enabled)
344 {
345 	if (enabled)
346 		return da9063_rtc_start_alarm(dev);
347 	else
348 		return da9063_rtc_stop_alarm(dev);
349 }
350 
351 static irqreturn_t da9063_alarm_event(int irq, void *data)
352 {
353 	struct da9063_compatible_rtc *rtc = data;
354 	const struct da9063_compatible_rtc_regmap *config = rtc->config;
355 
356 	regmap_update_bits(rtc->regmap,
357 			   config->rtc_alarm_year_reg,
358 			   config->rtc_alarm_on_mask,
359 			   0);
360 
361 	rtc->rtc_sync = true;
362 	rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
363 
364 	return IRQ_HANDLED;
365 }
366 
367 static const struct rtc_class_ops da9063_rtc_ops = {
368 	.read_time = da9063_rtc_read_time,
369 	.set_time = da9063_rtc_set_time,
370 	.read_alarm = da9063_rtc_read_alarm,
371 	.set_alarm = da9063_rtc_set_alarm,
372 	.alarm_irq_enable = da9063_rtc_alarm_irq_enable,
373 };
374 
375 static int da9063_rtc_probe(struct platform_device *pdev)
376 {
377 	struct da9063_compatible_rtc *rtc;
378 	const struct da9063_compatible_rtc_regmap *config;
379 	const struct of_device_id *match;
380 	int irq_alarm;
381 	u8 data[RTC_DATA_LEN];
382 	int ret;
383 
384 	if (!pdev->dev.of_node)
385 		return -ENXIO;
386 
387 	match = of_match_node(da9063_compatible_reg_id_table,
388 			      pdev->dev.of_node);
389 
390 	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
391 	if (!rtc)
392 		return -ENOMEM;
393 
394 	rtc->config = match->data;
395 	if (of_device_is_compatible(pdev->dev.of_node, "dlg,da9063-rtc")) {
396 		struct da9063 *chip = dev_get_drvdata(pdev->dev.parent);
397 
398 		if (chip->variant_code == PMIC_DA9063_AD)
399 			rtc->config = &da9063_ad_regs;
400 	}
401 
402 	rtc->regmap = dev_get_regmap(pdev->dev.parent, NULL);
403 	if (!rtc->regmap) {
404 		dev_warn(&pdev->dev, "Parent regmap unavailable.\n");
405 		return -ENXIO;
406 	}
407 
408 	config = rtc->config;
409 	ret = regmap_update_bits(rtc->regmap,
410 				 config->rtc_enable_reg,
411 				 config->rtc_enable_mask,
412 				 config->rtc_enable_mask);
413 	if (ret < 0) {
414 		dev_err(&pdev->dev, "Failed to enable RTC\n");
415 		return ret;
416 	}
417 
418 	ret = regmap_update_bits(rtc->regmap,
419 				 config->rtc_enable_32k_crystal_reg,
420 				 config->rtc_crystal_mask,
421 				 config->rtc_crystal_mask);
422 	if (ret < 0) {
423 		dev_err(&pdev->dev, "Failed to run 32kHz oscillator\n");
424 		return ret;
425 	}
426 
427 	ret = regmap_update_bits(rtc->regmap,
428 				 config->rtc_alarm_secs_reg,
429 				 config->rtc_alarm_status_mask,
430 				 0);
431 	if (ret < 0) {
432 		dev_err(&pdev->dev, "Failed to access RTC alarm register\n");
433 		return ret;
434 	}
435 
436 	ret = regmap_update_bits(rtc->regmap,
437 				 config->rtc_alarm_secs_reg,
438 				 DA9063_ALARM_STATUS_ALARM,
439 				 DA9063_ALARM_STATUS_ALARM);
440 	if (ret < 0) {
441 		dev_err(&pdev->dev, "Failed to access RTC alarm register\n");
442 		return ret;
443 	}
444 
445 	ret = regmap_update_bits(rtc->regmap,
446 				 config->rtc_alarm_year_reg,
447 				 config->rtc_tick_on_mask,
448 				 0);
449 	if (ret < 0) {
450 		dev_err(&pdev->dev, "Failed to disable TICKs\n");
451 		return ret;
452 	}
453 
454 	data[RTC_SEC] = 0;
455 	ret = regmap_bulk_read(rtc->regmap,
456 			       config->rtc_alarm_secs_reg,
457 			       &data[config->rtc_data_start],
458 			       config->rtc_alarm_len);
459 	if (ret < 0) {
460 		dev_err(&pdev->dev, "Failed to read initial alarm data: %d\n",
461 			ret);
462 		return ret;
463 	}
464 
465 	platform_set_drvdata(pdev, rtc);
466 
467 	rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
468 	if (IS_ERR(rtc->rtc_dev))
469 		return PTR_ERR(rtc->rtc_dev);
470 
471 	rtc->rtc_dev->ops = &da9063_rtc_ops;
472 	rtc->rtc_dev->range_min = RTC_TIMESTAMP_BEGIN_2000;
473 	rtc->rtc_dev->range_max = RTC_TIMESTAMP_END_2063;
474 
475 	da9063_data_to_tm(data, &rtc->alarm_time, rtc);
476 	rtc->rtc_sync = false;
477 
478 	/*
479 	 * TODO: some models have alarms on a minute boundary but still support
480 	 * real hardware interrupts. Add this once the core supports it.
481 	 */
482 	if (config->rtc_data_start != RTC_SEC)
483 		rtc->rtc_dev->uie_unsupported = 1;
484 
485 	irq_alarm = platform_get_irq_byname(pdev, "ALARM");
486 	if (irq_alarm < 0)
487 		return irq_alarm;
488 
489 	ret = devm_request_threaded_irq(&pdev->dev, irq_alarm, NULL,
490 					da9063_alarm_event,
491 					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
492 					"ALARM", rtc);
493 	if (ret)
494 		dev_err(&pdev->dev, "Failed to request ALARM IRQ %d: %d\n",
495 			irq_alarm, ret);
496 
497 	return rtc_register_device(rtc->rtc_dev);
498 }
499 
500 static struct platform_driver da9063_rtc_driver = {
501 	.probe		= da9063_rtc_probe,
502 	.driver		= {
503 		.name	= DA9063_DRVNAME_RTC,
504 		.of_match_table = da9063_compatible_reg_id_table,
505 	},
506 };
507 
508 module_platform_driver(da9063_rtc_driver);
509 
510 MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
511 MODULE_DESCRIPTION("Real time clock device driver for Dialog DA9063");
512 MODULE_LICENSE("GPL");
513 MODULE_ALIAS("platform:" DA9063_DRVNAME_RTC);
514