xref: /openbmc/linux/drivers/rtc/rtc-da9063.c (revision 4f3db074)
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 
42 struct 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 
53 static 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 
65 static 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 
88 static 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 
96 static 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 
104 static 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 
138 static 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 
153 static 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 
182 static 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 
216 static 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 
224 static 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 
237 static 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 
245 static 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;
336 err:
337 	return ret;
338 }
339 
340 static struct platform_driver da9063_rtc_driver = {
341 	.probe		= da9063_rtc_probe,
342 	.driver		= {
343 		.name	= DA9063_DRVNAME_RTC,
344 	},
345 };
346 
347 module_platform_driver(da9063_rtc_driver);
348 
349 MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
350 MODULE_DESCRIPTION("Real time clock device driver for Dialog DA9063");
351 MODULE_LICENSE("GPL v2");
352 MODULE_ALIAS("platform:" DA9063_DRVNAME_RTC);
353