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
28enum {
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
38struct 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
66struct 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
74static 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
103static 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
132static 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
160static 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};
165MODULE_DEVICE_TABLE(of, da9063_compatible_reg_id_table);
166
167static 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
182static 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
197static int da9063_rtc_stop_alarm(struct device *dev)
198{
199	struct da9063_compatible_rtc *rtc = dev_get_drvdata(dev);
200	const struct da9063_compatible_rtc_regmap *config = rtc->config;
201
202	return regmap_update_bits(rtc->regmap,
203				  config->rtc_alarm_year_reg,
204				  config->rtc_alarm_on_mask,
205				  0);
206}
207
208static int da9063_rtc_start_alarm(struct device *dev)
209{
210	struct da9063_compatible_rtc *rtc = dev_get_drvdata(dev);
211	const struct da9063_compatible_rtc_regmap *config = rtc->config;
212
213	return regmap_update_bits(rtc->regmap,
214				  config->rtc_alarm_year_reg,
215				  config->rtc_alarm_on_mask,
216				  config->rtc_alarm_on_mask);
217}
218
219static int da9063_rtc_read_time(struct device *dev, struct rtc_time *tm)
220{
221	struct da9063_compatible_rtc *rtc = dev_get_drvdata(dev);
222	const struct da9063_compatible_rtc_regmap *config = rtc->config;
223	unsigned long tm_secs;
224	unsigned long al_secs;
225	u8 data[RTC_DATA_LEN];
226	int ret;
227
228	ret = regmap_bulk_read(rtc->regmap,
229			       config->rtc_count_secs_reg,
230			       data, RTC_DATA_LEN);
231	if (ret < 0) {
232		dev_err(dev, "Failed to read RTC time data: %d\n", ret);
233		return ret;
234	}
235
236	if (!(data[RTC_SEC] & config->rtc_ready_to_read_mask)) {
237		dev_dbg(dev, "RTC not yet ready to be read by the host\n");
238		return -EINVAL;
239	}
240
241	da9063_data_to_tm(data, tm, rtc);
242
243	tm_secs = rtc_tm_to_time64(tm);
244	al_secs = rtc_tm_to_time64(&rtc->alarm_time);
245
246	/* handle the rtc synchronisation delay */
247	if (rtc->rtc_sync && al_secs - tm_secs == 1)
248		memcpy(tm, &rtc->alarm_time, sizeof(struct rtc_time));
249	else
250		rtc->rtc_sync = false;
251
252	return 0;
253}
254
255static int da9063_rtc_set_time(struct device *dev, struct rtc_time *tm)
256{
257	struct da9063_compatible_rtc *rtc = dev_get_drvdata(dev);
258	const struct da9063_compatible_rtc_regmap *config = rtc->config;
259	u8 data[RTC_DATA_LEN];
260	int ret;
261
262	da9063_tm_to_data(tm, data, rtc);
263	ret = regmap_bulk_write(rtc->regmap,
264				config->rtc_count_secs_reg,
265				data, RTC_DATA_LEN);
266	if (ret < 0)
267		dev_err(dev, "Failed to set RTC time data: %d\n", ret);
268
269	return ret;
270}
271
272static int da9063_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
273{
274	struct da9063_compatible_rtc *rtc = dev_get_drvdata(dev);
275	const struct da9063_compatible_rtc_regmap *config = rtc->config;
276	u8 data[RTC_DATA_LEN];
277	int ret;
278	unsigned int val;
279
280	data[RTC_SEC] = 0;
281	ret = regmap_bulk_read(rtc->regmap,
282			       config->rtc_alarm_secs_reg,
283			       &data[config->rtc_data_start],
284			       config->rtc_alarm_len);
285	if (ret < 0)
286		return ret;
287
288	da9063_data_to_tm(data, &alrm->time, rtc);
289
290	alrm->enabled = !!(data[RTC_YEAR] & config->rtc_alarm_on_mask);
291
292	ret = regmap_read(rtc->regmap,
293			  config->rtc_event_reg,
294			  &val);
295	if (ret < 0)
296		return ret;
297
298	if (val & config->rtc_event_alarm_mask)
299		alrm->pending = 1;
300	else
301		alrm->pending = 0;
302
303	return 0;
304}
305
306static int da9063_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
307{
308	struct da9063_compatible_rtc *rtc = dev_get_drvdata(dev);
309	const struct da9063_compatible_rtc_regmap *config = rtc->config;
310	u8 data[RTC_DATA_LEN];
311	int ret;
312
313	da9063_tm_to_data(&alrm->time, data, rtc);
314
315	ret = da9063_rtc_stop_alarm(dev);
316	if (ret < 0) {
317		dev_err(dev, "Failed to stop alarm: %d\n", ret);
318		return ret;
319	}
320
321	ret = regmap_bulk_write(rtc->regmap,
322				config->rtc_alarm_secs_reg,
323				&data[config->rtc_data_start],
324				config->rtc_alarm_len);
325	if (ret < 0) {
326		dev_err(dev, "Failed to write alarm: %d\n", ret);
327		return ret;
328	}
329
330	da9063_data_to_tm(data, &rtc->alarm_time, rtc);
331
332	if (alrm->enabled) {
333		ret = da9063_rtc_start_alarm(dev);
334		if (ret < 0) {
335			dev_err(dev, "Failed to start alarm: %d\n", ret);
336			return ret;
337		}
338	}
339
340	return ret;
341}
342
343static int da9063_rtc_alarm_irq_enable(struct device *dev,
344				       unsigned int enabled)
345{
346	if (enabled)
347		return da9063_rtc_start_alarm(dev);
348	else
349		return da9063_rtc_stop_alarm(dev);
350}
351
352static irqreturn_t da9063_alarm_event(int irq, void *data)
353{
354	struct da9063_compatible_rtc *rtc = data;
355	const struct da9063_compatible_rtc_regmap *config = rtc->config;
356
357	regmap_update_bits(rtc->regmap,
358			   config->rtc_alarm_year_reg,
359			   config->rtc_alarm_on_mask,
360			   0);
361
362	rtc->rtc_sync = true;
363	rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
364
365	return IRQ_HANDLED;
366}
367
368static const struct rtc_class_ops da9063_rtc_ops = {
369	.read_time = da9063_rtc_read_time,
370	.set_time = da9063_rtc_set_time,
371	.read_alarm = da9063_rtc_read_alarm,
372	.set_alarm = da9063_rtc_set_alarm,
373	.alarm_irq_enable = da9063_rtc_alarm_irq_enable,
374};
375
376static int da9063_rtc_probe(struct platform_device *pdev)
377{
378	struct da9063_compatible_rtc *rtc;
379	const struct da9063_compatible_rtc_regmap *config;
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	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
388	if (!rtc)
389		return -ENOMEM;
390
391	rtc->config = device_get_match_data(&pdev->dev);
392	if (of_device_is_compatible(pdev->dev.of_node, "dlg,da9063-rtc")) {
393		struct da9063 *chip = dev_get_drvdata(pdev->dev.parent);
394
395		if (chip->variant_code == PMIC_DA9063_AD)
396			rtc->config = &da9063_ad_regs;
397	}
398
399	rtc->regmap = dev_get_regmap(pdev->dev.parent, NULL);
400	if (!rtc->regmap) {
401		dev_warn(&pdev->dev, "Parent regmap unavailable.\n");
402		return -ENXIO;
403	}
404
405	config = rtc->config;
406	ret = regmap_update_bits(rtc->regmap,
407				 config->rtc_enable_reg,
408				 config->rtc_enable_mask,
409				 config->rtc_enable_mask);
410	if (ret < 0)
411		return dev_err_probe(&pdev->dev, ret, "Failed to enable RTC\n");
412
413	ret = regmap_update_bits(rtc->regmap,
414				 config->rtc_enable_32k_crystal_reg,
415				 config->rtc_crystal_mask,
416				 config->rtc_crystal_mask);
417	if (ret < 0)
418		return dev_err_probe(&pdev->dev, ret,
419				     "Failed to run 32kHz oscillator\n");
420
421	ret = regmap_update_bits(rtc->regmap,
422				 config->rtc_alarm_secs_reg,
423				 config->rtc_alarm_status_mask,
424				 0);
425	if (ret < 0)
426		return dev_err_probe(&pdev->dev, ret,
427				     "Failed to access RTC alarm register\n");
428
429	ret = regmap_update_bits(rtc->regmap,
430				 config->rtc_alarm_secs_reg,
431				 DA9063_ALARM_STATUS_ALARM,
432				 DA9063_ALARM_STATUS_ALARM);
433	if (ret < 0)
434		return dev_err_probe(&pdev->dev, ret,
435				     "Failed to access RTC alarm register\n");
436
437	ret = regmap_update_bits(rtc->regmap,
438				 config->rtc_alarm_year_reg,
439				 config->rtc_tick_on_mask,
440				 0);
441	if (ret < 0)
442		return dev_err_probe(&pdev->dev, ret,
443				     "Failed to disable TICKs\n");
444
445	data[RTC_SEC] = 0;
446	ret = regmap_bulk_read(rtc->regmap,
447			       config->rtc_alarm_secs_reg,
448			       &data[config->rtc_data_start],
449			       config->rtc_alarm_len);
450	if (ret < 0)
451		return dev_err_probe(&pdev->dev, ret,
452				     "Failed to read initial alarm data\n");
453
454	platform_set_drvdata(pdev, rtc);
455
456	rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
457	if (IS_ERR(rtc->rtc_dev))
458		return PTR_ERR(rtc->rtc_dev);
459
460	rtc->rtc_dev->ops = &da9063_rtc_ops;
461	rtc->rtc_dev->range_min = RTC_TIMESTAMP_BEGIN_2000;
462	rtc->rtc_dev->range_max = RTC_TIMESTAMP_END_2063;
463
464	da9063_data_to_tm(data, &rtc->alarm_time, rtc);
465	rtc->rtc_sync = false;
466
467	if (config->rtc_data_start != RTC_SEC) {
468		set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->rtc_dev->features);
469		/*
470		 * TODO: some models have alarms on a minute boundary but still
471		 * support real hardware interrupts.
472		 */
473		clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->rtc_dev->features);
474	}
475
476	irq_alarm = platform_get_irq_byname_optional(pdev, "ALARM");
477	if (irq_alarm >= 0) {
478		ret = devm_request_threaded_irq(&pdev->dev, irq_alarm, NULL,
479						da9063_alarm_event,
480						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
481						"ALARM", rtc);
482		if (ret)
483			dev_err(&pdev->dev,
484				"Failed to request ALARM IRQ %d: %d\n",
485				irq_alarm, ret);
486
487		ret = dev_pm_set_wake_irq(&pdev->dev, irq_alarm);
488		if (ret)
489			dev_warn(&pdev->dev,
490				 "Failed to set IRQ %d as a wake IRQ: %d\n",
491				 irq_alarm, ret);
492
493		device_init_wakeup(&pdev->dev, true);
494	}  else if (irq_alarm != -ENXIO) {
495		return irq_alarm;
496	} else {
497		clear_bit(RTC_FEATURE_ALARM, rtc->rtc_dev->features);
498	}
499
500	return devm_rtc_register_device(rtc->rtc_dev);
501}
502
503static struct platform_driver da9063_rtc_driver = {
504	.probe		= da9063_rtc_probe,
505	.driver		= {
506		.name	= DA9063_DRVNAME_RTC,
507		.of_match_table = da9063_compatible_reg_id_table,
508	},
509};
510
511module_platform_driver(da9063_rtc_driver);
512
513MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
514MODULE_DESCRIPTION("Real time clock device driver for Dialog DA9063");
515MODULE_LICENSE("GPL");
516MODULE_ALIAS("platform:" DA9063_DRVNAME_RTC);
517