xref: /openbmc/linux/drivers/rtc/rtc-bd70528.c (revision 2cf1c348)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 //
3 // Copyright (C) 2018 ROHM Semiconductors
4 //
5 // RTC driver for ROHM BD71828 and BD71815 PMIC
6 
7 #include <linux/bcd.h>
8 #include <linux/mfd/rohm-bd71815.h>
9 #include <linux/mfd/rohm-bd71828.h>
10 #include <linux/module.h>
11 #include <linux/of.h>
12 #include <linux/platform_device.h>
13 #include <linux/regmap.h>
14 #include <linux/rtc.h>
15 
16 /*
17  * On BD71828 and BD71815 the ALM0 MASK is 14 bytes after the ALM0
18  * block start
19  */
20 #define BD718XX_ALM_EN_OFFSET 14
21 
22 /*
23  * We read regs RTC_SEC => RTC_YEAR
24  * this struct is ordered according to chip registers.
25  * Keep it u8 only (or packed) to avoid padding issues.
26  */
27 struct bd70528_rtc_day {
28 	u8 sec;
29 	u8 min;
30 	u8 hour;
31 } __packed;
32 
33 struct bd70528_rtc_data {
34 	struct bd70528_rtc_day time;
35 	u8 week;
36 	u8 day;
37 	u8 month;
38 	u8 year;
39 } __packed;
40 
41 struct bd71828_rtc_alm {
42 	struct bd70528_rtc_data alm0;
43 	struct bd70528_rtc_data alm1;
44 	u8 alm_mask;
45 	u8 alm1_mask;
46 } __packed;
47 
48 struct bd70528_rtc {
49 	struct rohm_regmap_dev *parent;
50 	struct regmap *regmap;
51 	struct device *dev;
52 	u8 reg_time_start;
53 	u8 bd718xx_alm_block_start;
54 };
55 
56 static inline void tmday2rtc(struct rtc_time *t, struct bd70528_rtc_day *d)
57 {
58 	d->sec &= ~BD70528_MASK_RTC_SEC;
59 	d->min &= ~BD70528_MASK_RTC_MINUTE;
60 	d->hour &= ~BD70528_MASK_RTC_HOUR;
61 	d->sec |= bin2bcd(t->tm_sec);
62 	d->min |= bin2bcd(t->tm_min);
63 	d->hour |= bin2bcd(t->tm_hour);
64 }
65 
66 static inline void tm2rtc(struct rtc_time *t, struct bd70528_rtc_data *r)
67 {
68 	r->day &= ~BD70528_MASK_RTC_DAY;
69 	r->week &= ~BD70528_MASK_RTC_WEEK;
70 	r->month &= ~BD70528_MASK_RTC_MONTH;
71 	/*
72 	 * PM and 24H bits are not used by Wake - thus we clear them
73 	 * here and not in tmday2rtc() which is also used by wake.
74 	 */
75 	r->time.hour &= ~(BD70528_MASK_RTC_HOUR_PM | BD70528_MASK_RTC_HOUR_24H);
76 
77 	tmday2rtc(t, &r->time);
78 	/*
79 	 * We do always set time in 24H mode.
80 	 */
81 	r->time.hour |= BD70528_MASK_RTC_HOUR_24H;
82 	r->day |= bin2bcd(t->tm_mday);
83 	r->week |= bin2bcd(t->tm_wday);
84 	r->month |= bin2bcd(t->tm_mon + 1);
85 	r->year = bin2bcd(t->tm_year - 100);
86 }
87 
88 static inline void rtc2tm(struct bd70528_rtc_data *r, struct rtc_time *t)
89 {
90 	t->tm_sec = bcd2bin(r->time.sec & BD70528_MASK_RTC_SEC);
91 	t->tm_min = bcd2bin(r->time.min & BD70528_MASK_RTC_MINUTE);
92 	t->tm_hour = bcd2bin(r->time.hour & BD70528_MASK_RTC_HOUR);
93 	/*
94 	 * If RTC is in 12H mode, then bit BD70528_MASK_RTC_HOUR_PM
95 	 * is not BCD value but tells whether it is AM or PM
96 	 */
97 	if (!(r->time.hour & BD70528_MASK_RTC_HOUR_24H)) {
98 		t->tm_hour %= 12;
99 		if (r->time.hour & BD70528_MASK_RTC_HOUR_PM)
100 			t->tm_hour += 12;
101 	}
102 	t->tm_mday = bcd2bin(r->day & BD70528_MASK_RTC_DAY);
103 	t->tm_mon = bcd2bin(r->month & BD70528_MASK_RTC_MONTH) - 1;
104 	t->tm_year = 100 + bcd2bin(r->year & BD70528_MASK_RTC_YEAR);
105 	t->tm_wday = bcd2bin(r->week & BD70528_MASK_RTC_WEEK);
106 }
107 
108 static int bd71828_set_alarm(struct device *dev, struct rtc_wkalrm *a)
109 {
110 	int ret;
111 	struct bd71828_rtc_alm alm;
112 	struct bd70528_rtc *r = dev_get_drvdata(dev);
113 
114 	ret = regmap_bulk_read(r->regmap, r->bd718xx_alm_block_start, &alm,
115 			       sizeof(alm));
116 	if (ret) {
117 		dev_err(dev, "Failed to read alarm regs\n");
118 		return ret;
119 	}
120 
121 	tm2rtc(&a->time, &alm.alm0);
122 
123 	if (!a->enabled)
124 		alm.alm_mask &= ~BD70528_MASK_ALM_EN;
125 	else
126 		alm.alm_mask |= BD70528_MASK_ALM_EN;
127 
128 	ret = regmap_bulk_write(r->regmap, r->bd718xx_alm_block_start, &alm,
129 				sizeof(alm));
130 	if (ret)
131 		dev_err(dev, "Failed to set alarm time\n");
132 
133 	return ret;
134 
135 }
136 
137 static int bd71828_read_alarm(struct device *dev, struct rtc_wkalrm *a)
138 {
139 	int ret;
140 	struct bd71828_rtc_alm alm;
141 	struct bd70528_rtc *r = dev_get_drvdata(dev);
142 
143 	ret = regmap_bulk_read(r->regmap, r->bd718xx_alm_block_start, &alm,
144 			       sizeof(alm));
145 	if (ret) {
146 		dev_err(dev, "Failed to read alarm regs\n");
147 		return ret;
148 	}
149 
150 	rtc2tm(&alm.alm0, &a->time);
151 	a->time.tm_mday = -1;
152 	a->time.tm_mon = -1;
153 	a->time.tm_year = -1;
154 	a->enabled = !!(alm.alm_mask & BD70528_MASK_ALM_EN);
155 	a->pending = 0;
156 
157 	return 0;
158 }
159 
160 static int bd71828_set_time(struct device *dev, struct rtc_time *t)
161 {
162 	int ret;
163 	struct bd70528_rtc_data rtc_data;
164 	struct bd70528_rtc *r = dev_get_drvdata(dev);
165 
166 	ret = regmap_bulk_read(r->regmap, r->reg_time_start, &rtc_data,
167 			       sizeof(rtc_data));
168 	if (ret) {
169 		dev_err(dev, "Failed to read RTC time registers\n");
170 		return ret;
171 	}
172 	tm2rtc(t, &rtc_data);
173 
174 	ret = regmap_bulk_write(r->regmap, r->reg_time_start, &rtc_data,
175 				sizeof(rtc_data));
176 	if (ret)
177 		dev_err(dev, "Failed to set RTC time\n");
178 
179 	return ret;
180 }
181 
182 static int bd70528_get_time(struct device *dev, struct rtc_time *t)
183 {
184 	struct bd70528_rtc *r = dev_get_drvdata(dev);
185 	struct bd70528_rtc_data rtc_data;
186 	int ret;
187 
188 	/* read the RTC date and time registers all at once */
189 	ret = regmap_bulk_read(r->regmap, r->reg_time_start, &rtc_data,
190 			       sizeof(rtc_data));
191 	if (ret) {
192 		dev_err(dev, "Failed to read RTC time (err %d)\n", ret);
193 		return ret;
194 	}
195 
196 	rtc2tm(&rtc_data, t);
197 
198 	return 0;
199 }
200 
201 static int bd71828_alm_enable(struct device *dev, unsigned int enabled)
202 {
203 	int ret;
204 	struct bd70528_rtc *r = dev_get_drvdata(dev);
205 	unsigned int enableval = BD70528_MASK_ALM_EN;
206 
207 	if (!enabled)
208 		enableval = 0;
209 
210 	ret = regmap_update_bits(r->regmap, r->bd718xx_alm_block_start +
211 				 BD718XX_ALM_EN_OFFSET, BD70528_MASK_ALM_EN,
212 				 enableval);
213 	if (ret)
214 		dev_err(dev, "Failed to change alarm state\n");
215 
216 	return ret;
217 }
218 
219 static const struct rtc_class_ops bd71828_rtc_ops = {
220 	.read_time		= bd70528_get_time,
221 	.set_time		= bd71828_set_time,
222 	.read_alarm		= bd71828_read_alarm,
223 	.set_alarm		= bd71828_set_alarm,
224 	.alarm_irq_enable	= bd71828_alm_enable,
225 };
226 
227 static irqreturn_t alm_hndlr(int irq, void *data)
228 {
229 	struct rtc_device *rtc = data;
230 
231 	rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF | RTC_PF);
232 	return IRQ_HANDLED;
233 }
234 
235 static int bd70528_probe(struct platform_device *pdev)
236 {
237 	struct bd70528_rtc *bd_rtc;
238 	const struct rtc_class_ops *rtc_ops;
239 	const char *irq_name;
240 	int ret;
241 	struct rtc_device *rtc;
242 	int irq;
243 	unsigned int hr;
244 	u8 hour_reg;
245 	enum rohm_chip_type chip = platform_get_device_id(pdev)->driver_data;
246 
247 	bd_rtc = devm_kzalloc(&pdev->dev, sizeof(*bd_rtc), GFP_KERNEL);
248 	if (!bd_rtc)
249 		return -ENOMEM;
250 
251 	bd_rtc->regmap = dev_get_regmap(pdev->dev.parent, NULL);
252 	if (!bd_rtc->regmap) {
253 		dev_err(&pdev->dev, "No regmap\n");
254 		return -EINVAL;
255 	}
256 
257 	bd_rtc->dev = &pdev->dev;
258 	rtc_ops = &bd71828_rtc_ops;
259 
260 	switch (chip) {
261 	case ROHM_CHIP_TYPE_BD71815:
262 		irq_name = "bd71815-rtc-alm-0";
263 		bd_rtc->reg_time_start = BD71815_REG_RTC_START;
264 
265 		/*
266 		 * See also BD718XX_ALM_EN_OFFSET:
267 		 * This works for BD71828 and BD71815 as they have same offset
268 		 * between ALM0 start and ALM0_MASK. If new ICs are to be
269 		 * added this requires proper check as ALM0_MASK is not located
270 		 * at the end of ALM0 block - but after all ALM blocks so if
271 		 * amount of ALMs differ the offset to enable/disable is likely
272 		 * to be incorrect and enable/disable must be given as own
273 		 * reg address here.
274 		 */
275 		bd_rtc->bd718xx_alm_block_start = BD71815_REG_RTC_ALM_START;
276 		hour_reg = BD71815_REG_HOUR;
277 		break;
278 	case ROHM_CHIP_TYPE_BD71828:
279 		irq_name = "bd71828-rtc-alm-0";
280 		bd_rtc->reg_time_start = BD71828_REG_RTC_START;
281 		bd_rtc->bd718xx_alm_block_start = BD71828_REG_RTC_ALM_START;
282 		hour_reg = BD71828_REG_RTC_HOUR;
283 		break;
284 	default:
285 		dev_err(&pdev->dev, "Unknown chip\n");
286 		return -ENOENT;
287 	}
288 
289 	irq = platform_get_irq_byname(pdev, irq_name);
290 
291 	if (irq < 0)
292 		return irq;
293 
294 	platform_set_drvdata(pdev, bd_rtc);
295 
296 	ret = regmap_read(bd_rtc->regmap, hour_reg, &hr);
297 
298 	if (ret) {
299 		dev_err(&pdev->dev, "Failed to reag RTC clock\n");
300 		return ret;
301 	}
302 
303 	if (!(hr & BD70528_MASK_RTC_HOUR_24H)) {
304 		struct rtc_time t;
305 
306 		ret = rtc_ops->read_time(&pdev->dev, &t);
307 
308 		if (!ret)
309 			ret = rtc_ops->set_time(&pdev->dev, &t);
310 
311 		if (ret) {
312 			dev_err(&pdev->dev,
313 				"Setting 24H clock for RTC failed\n");
314 			return ret;
315 		}
316 	}
317 
318 	device_set_wakeup_capable(&pdev->dev, true);
319 	device_wakeup_enable(&pdev->dev);
320 
321 	rtc = devm_rtc_allocate_device(&pdev->dev);
322 	if (IS_ERR(rtc)) {
323 		dev_err(&pdev->dev, "RTC device creation failed\n");
324 		return PTR_ERR(rtc);
325 	}
326 
327 	rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
328 	rtc->range_max = RTC_TIMESTAMP_END_2099;
329 	rtc->ops = rtc_ops;
330 
331 	/* Request alarm IRQ prior to registerig the RTC */
332 	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, &alm_hndlr,
333 					IRQF_ONESHOT, "bd70528-rtc", rtc);
334 	if (ret)
335 		return ret;
336 
337 	return devm_rtc_register_device(rtc);
338 }
339 
340 static const struct platform_device_id bd718x7_rtc_id[] = {
341 	{ "bd71828-rtc", ROHM_CHIP_TYPE_BD71828 },
342 	{ "bd71815-rtc", ROHM_CHIP_TYPE_BD71815 },
343 	{ },
344 };
345 MODULE_DEVICE_TABLE(platform, bd718x7_rtc_id);
346 
347 static struct platform_driver bd70528_rtc = {
348 	.driver = {
349 		.name = "bd70528-rtc"
350 	},
351 	.probe = bd70528_probe,
352 	.id_table = bd718x7_rtc_id,
353 };
354 
355 module_platform_driver(bd70528_rtc);
356 
357 MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
358 MODULE_DESCRIPTION("ROHM BD71828 and BD71815 PMIC RTC driver");
359 MODULE_LICENSE("GPL");
360 MODULE_ALIAS("platform:bd70528-rtc");
361