1/* rtc-da9063.c - Real time clock device driver for DA9063
2 * Copyright (C) 2013-14  Dialog Semiconductor Ltd.
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 * Library General Public License for more details.
13 */
14
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/init.h>
18#include <linux/platform_device.h>
19#include <linux/interrupt.h>
20#include <linux/rtc.h>
21#include <linux/slab.h>
22#include <linux/delay.h>
23#include <linux/regmap.h>
24#include <linux/mfd/da9063/registers.h>
25#include <linux/mfd/da9063/core.h>
26
27#define YEARS_TO_DA9063(year)		((year) - 100)
28#define MONTHS_TO_DA9063(month)		((month) + 1)
29#define YEARS_FROM_DA9063(year)		((year) + 100)
30#define MONTHS_FROM_DA9063(month)	((month) - 1)
31
32#define RTC_ALARM_DATA_LEN (DA9063_AD_REG_ALARM_Y - DA9063_AD_REG_ALARM_MI + 1)
33
34#define RTC_DATA_LEN	(DA9063_REG_COUNT_Y - DA9063_REG_COUNT_S + 1)
35#define RTC_SEC		0
36#define RTC_MIN		1
37#define RTC_HOUR	2
38#define RTC_DAY		3
39#define RTC_MONTH	4
40#define RTC_YEAR	5
41
42struct da9063_rtc {
43	struct rtc_device	*rtc_dev;
44	struct da9063		*hw;
45	struct rtc_time		alarm_time;
46	bool			rtc_sync;
47	int			alarm_year;
48	int			alarm_start;
49	int			alarm_len;
50	int			data_start;
51};
52
53static void da9063_data_to_tm(u8 *data, struct rtc_time *tm)
54{
55	tm->tm_sec  = data[RTC_SEC]  & DA9063_COUNT_SEC_MASK;
56	tm->tm_min  = data[RTC_MIN]  & DA9063_COUNT_MIN_MASK;
57	tm->tm_hour = data[RTC_HOUR] & DA9063_COUNT_HOUR_MASK;
58	tm->tm_mday = data[RTC_DAY]  & DA9063_COUNT_DAY_MASK;
59	tm->tm_mon  = MONTHS_FROM_DA9063(data[RTC_MONTH] &
60					 DA9063_COUNT_MONTH_MASK);
61	tm->tm_year = YEARS_FROM_DA9063(data[RTC_YEAR] &
62					DA9063_COUNT_YEAR_MASK);
63}
64
65static void da9063_tm_to_data(struct rtc_time *tm, u8 *data)
66{
67	data[RTC_SEC] &= ~DA9063_COUNT_SEC_MASK;
68	data[RTC_SEC] |= tm->tm_sec & DA9063_COUNT_SEC_MASK;
69
70	data[RTC_MIN] &= ~DA9063_COUNT_MIN_MASK;
71	data[RTC_MIN] |= tm->tm_min & DA9063_COUNT_MIN_MASK;
72
73	data[RTC_HOUR] &= ~DA9063_COUNT_HOUR_MASK;
74	data[RTC_HOUR] |= tm->tm_hour & DA9063_COUNT_HOUR_MASK;
75
76	data[RTC_DAY] &= ~DA9063_COUNT_DAY_MASK;
77	data[RTC_DAY] |= tm->tm_mday & DA9063_COUNT_DAY_MASK;
78
79	data[RTC_MONTH] &= ~DA9063_COUNT_MONTH_MASK;
80	data[RTC_MONTH] |= MONTHS_TO_DA9063(tm->tm_mon) &
81				DA9063_COUNT_MONTH_MASK;
82
83	data[RTC_YEAR] &= ~DA9063_COUNT_YEAR_MASK;
84	data[RTC_YEAR] |= YEARS_TO_DA9063(tm->tm_year) &
85				DA9063_COUNT_YEAR_MASK;
86}
87
88static int da9063_rtc_stop_alarm(struct device *dev)
89{
90	struct da9063_rtc *rtc = dev_get_drvdata(dev);
91
92	return regmap_update_bits(rtc->hw->regmap, rtc->alarm_year,
93				  DA9063_ALARM_ON, 0);
94}
95
96static int da9063_rtc_start_alarm(struct device *dev)
97{
98	struct da9063_rtc *rtc = dev_get_drvdata(dev);
99
100	return regmap_update_bits(rtc->hw->regmap, rtc->alarm_year,
101				  DA9063_ALARM_ON, DA9063_ALARM_ON);
102}
103
104static int da9063_rtc_read_time(struct device *dev, struct rtc_time *tm)
105{
106	struct da9063_rtc *rtc = dev_get_drvdata(dev);
107	unsigned long tm_secs;
108	unsigned long al_secs;
109	u8 data[RTC_DATA_LEN];
110	int ret;
111
112	ret = regmap_bulk_read(rtc->hw->regmap, DA9063_REG_COUNT_S,
113			       data, RTC_DATA_LEN);
114	if (ret < 0) {
115		dev_err(dev, "Failed to read RTC time data: %d\n", ret);
116		return ret;
117	}
118
119	if (!(data[RTC_SEC] & DA9063_RTC_READ)) {
120		dev_dbg(dev, "RTC not yet ready to be read by the host\n");
121		return -EINVAL;
122	}
123
124	da9063_data_to_tm(data, tm);
125
126	rtc_tm_to_time(tm, &tm_secs);
127	rtc_tm_to_time(&rtc->alarm_time, &al_secs);
128
129	/* handle the rtc synchronisation delay */
130	if (rtc->rtc_sync == true && al_secs - tm_secs == 1)
131		memcpy(tm, &rtc->alarm_time, sizeof(struct rtc_time));
132	else
133		rtc->rtc_sync = false;
134
135	return rtc_valid_tm(tm);
136}
137
138static int da9063_rtc_set_time(struct device *dev, struct rtc_time *tm)
139{
140	struct da9063_rtc *rtc = dev_get_drvdata(dev);
141	u8 data[RTC_DATA_LEN];
142	int ret;
143
144	da9063_tm_to_data(tm, data);
145	ret = regmap_bulk_write(rtc->hw->regmap, DA9063_REG_COUNT_S,
146				data, RTC_DATA_LEN);
147	if (ret < 0)
148		dev_err(dev, "Failed to set RTC time data: %d\n", ret);
149
150	return ret;
151}
152
153static int da9063_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
154{
155	struct da9063_rtc *rtc = dev_get_drvdata(dev);
156	u8 data[RTC_DATA_LEN];
157	int ret;
158	unsigned int val;
159
160	data[RTC_SEC] = 0;
161	ret = regmap_bulk_read(rtc->hw->regmap, rtc->alarm_start,
162			       &data[rtc->data_start], rtc->alarm_len);
163	if (ret < 0)
164		return ret;
165
166	da9063_data_to_tm(data, &alrm->time);
167
168	alrm->enabled = !!(data[RTC_YEAR] & DA9063_ALARM_ON);
169
170	ret = regmap_read(rtc->hw->regmap, DA9063_REG_EVENT_A, &val);
171	if (ret < 0)
172		return ret;
173
174	if (val & (DA9063_E_ALARM))
175		alrm->pending = 1;
176	else
177		alrm->pending = 0;
178
179	return 0;
180}
181
182static int da9063_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
183{
184	struct da9063_rtc *rtc = dev_get_drvdata(dev);
185	u8 data[RTC_DATA_LEN];
186	int ret;
187
188	da9063_tm_to_data(&alrm->time, data);
189
190	ret = da9063_rtc_stop_alarm(dev);
191	if (ret < 0) {
192		dev_err(dev, "Failed to stop alarm: %d\n", ret);
193		return ret;
194	}
195
196	ret = regmap_bulk_write(rtc->hw->regmap, rtc->alarm_start,
197			       &data[rtc->data_start], rtc->alarm_len);
198	if (ret < 0) {
199		dev_err(dev, "Failed to write alarm: %d\n", ret);
200		return ret;
201	}
202
203	da9063_data_to_tm(data, &rtc->alarm_time);
204
205	if (alrm->enabled) {
206		ret = da9063_rtc_start_alarm(dev);
207		if (ret < 0) {
208			dev_err(dev, "Failed to start alarm: %d\n", ret);
209			return ret;
210		}
211	}
212
213	return ret;
214}
215
216static int da9063_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
217{
218	if (enabled)
219		return da9063_rtc_start_alarm(dev);
220	else
221		return da9063_rtc_stop_alarm(dev);
222}
223
224static irqreturn_t da9063_alarm_event(int irq, void *data)
225{
226	struct da9063_rtc *rtc = data;
227
228	regmap_update_bits(rtc->hw->regmap, rtc->alarm_year,
229			   DA9063_ALARM_ON, 0);
230
231	rtc->rtc_sync = true;
232	rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
233
234	return IRQ_HANDLED;
235}
236
237static const struct rtc_class_ops da9063_rtc_ops = {
238	.read_time = da9063_rtc_read_time,
239	.set_time = da9063_rtc_set_time,
240	.read_alarm = da9063_rtc_read_alarm,
241	.set_alarm = da9063_rtc_set_alarm,
242	.alarm_irq_enable = da9063_rtc_alarm_irq_enable,
243};
244
245static int da9063_rtc_probe(struct platform_device *pdev)
246{
247	struct da9063 *da9063 = dev_get_drvdata(pdev->dev.parent);
248	struct da9063_rtc *rtc;
249	int irq_alarm;
250	u8 data[RTC_DATA_LEN];
251	int ret;
252
253	ret = regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_E,
254				 DA9063_RTC_EN, DA9063_RTC_EN);
255	if (ret < 0) {
256		dev_err(&pdev->dev, "Failed to enable RTC\n");
257		goto err;
258	}
259
260	ret = regmap_update_bits(da9063->regmap, DA9063_REG_EN_32K,
261				 DA9063_CRYSTAL, DA9063_CRYSTAL);
262	if (ret < 0) {
263		dev_err(&pdev->dev, "Failed to run 32kHz oscillator\n");
264		goto err;
265	}
266
267	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
268	if (!rtc)
269		return -ENOMEM;
270
271	if (da9063->variant_code == PMIC_DA9063_AD) {
272		rtc->alarm_year = DA9063_AD_REG_ALARM_Y;
273		rtc->alarm_start = DA9063_AD_REG_ALARM_MI;
274		rtc->alarm_len = RTC_ALARM_DATA_LEN;
275		rtc->data_start = RTC_MIN;
276	} else {
277		rtc->alarm_year = DA9063_BB_REG_ALARM_Y;
278		rtc->alarm_start = DA9063_BB_REG_ALARM_S;
279		rtc->alarm_len = RTC_DATA_LEN;
280		rtc->data_start = RTC_SEC;
281	}
282
283	ret = regmap_update_bits(da9063->regmap, rtc->alarm_start,
284			DA9063_ALARM_STATUS_TICK | DA9063_ALARM_STATUS_ALARM,
285			0);
286	if (ret < 0) {
287		dev_err(&pdev->dev, "Failed to access RTC alarm register\n");
288		goto err;
289	}
290
291	ret = regmap_update_bits(da9063->regmap, rtc->alarm_start,
292				 DA9063_ALARM_STATUS_ALARM,
293				 DA9063_ALARM_STATUS_ALARM);
294	if (ret < 0) {
295		dev_err(&pdev->dev, "Failed to access RTC alarm register\n");
296		goto err;
297	}
298
299	ret = regmap_update_bits(da9063->regmap, rtc->alarm_year,
300				 DA9063_TICK_ON, 0);
301	if (ret < 0) {
302		dev_err(&pdev->dev, "Failed to disable TICKs\n");
303		goto err;
304	}
305
306	data[RTC_SEC] = 0;
307	ret = regmap_bulk_read(da9063->regmap, rtc->alarm_start,
308			       &data[rtc->data_start], rtc->alarm_len);
309	if (ret < 0) {
310		dev_err(&pdev->dev, "Failed to read initial alarm data: %d\n",
311			ret);
312		goto err;
313	}
314
315	platform_set_drvdata(pdev, rtc);
316
317	irq_alarm = platform_get_irq_byname(pdev, "ALARM");
318	ret = devm_request_threaded_irq(&pdev->dev, irq_alarm, NULL,
319					da9063_alarm_event,
320					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
321					"ALARM", rtc);
322	if (ret) {
323		dev_err(&pdev->dev, "Failed to request ALARM IRQ %d: %d\n",
324			irq_alarm, ret);
325		goto err;
326	}
327
328	rtc->hw = da9063;
329	rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, DA9063_DRVNAME_RTC,
330					   &da9063_rtc_ops, THIS_MODULE);
331	if (IS_ERR(rtc->rtc_dev))
332		return PTR_ERR(rtc->rtc_dev);
333
334	da9063_data_to_tm(data, &rtc->alarm_time);
335	rtc->rtc_sync = false;
336err:
337	return ret;
338}
339
340static struct platform_driver da9063_rtc_driver = {
341	.probe		= da9063_rtc_probe,
342	.driver		= {
343		.name	= DA9063_DRVNAME_RTC,
344	},
345};
346
347module_platform_driver(da9063_rtc_driver);
348
349MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
350MODULE_DESCRIPTION("Real time clock device driver for Dialog DA9063");
351MODULE_LICENSE("GPL v2");
352MODULE_ALIAS("platform:" DA9063_DRVNAME_RTC);
353