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
tmday2rtc(struct rtc_time * t,struct bd70528_rtc_day * d)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
tm2rtc(struct rtc_time * t,struct bd70528_rtc_data * r)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
rtc2tm(struct bd70528_rtc_data * r,struct rtc_time * t)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
bd71828_set_alarm(struct device * dev,struct rtc_wkalrm * a)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
bd71828_read_alarm(struct device * dev,struct rtc_wkalrm * a)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
bd71828_set_time(struct device * dev,struct rtc_time * t)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
bd70528_get_time(struct device * dev,struct rtc_time * t)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
bd71828_alm_enable(struct device * dev,unsigned int enabled)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
alm_hndlr(int irq,void * data)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
bd70528_probe(struct platform_device * pdev)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 int ret;
240 struct rtc_device *rtc;
241 int irq;
242 unsigned int hr;
243 u8 hour_reg;
244 enum rohm_chip_type chip = platform_get_device_id(pdev)->driver_data;
245
246 bd_rtc = devm_kzalloc(&pdev->dev, sizeof(*bd_rtc), GFP_KERNEL);
247 if (!bd_rtc)
248 return -ENOMEM;
249
250 bd_rtc->regmap = dev_get_regmap(pdev->dev.parent, NULL);
251 if (!bd_rtc->regmap) {
252 dev_err(&pdev->dev, "No regmap\n");
253 return -EINVAL;
254 }
255
256 bd_rtc->dev = &pdev->dev;
257 rtc_ops = &bd71828_rtc_ops;
258
259 switch (chip) {
260 case ROHM_CHIP_TYPE_BD71815:
261 bd_rtc->reg_time_start = BD71815_REG_RTC_START;
262
263 /*
264 * See also BD718XX_ALM_EN_OFFSET:
265 * This works for BD71828 and BD71815 as they have same offset
266 * between ALM0 start and ALM0_MASK. If new ICs are to be
267 * added this requires proper check as ALM0_MASK is not located
268 * at the end of ALM0 block - but after all ALM blocks so if
269 * amount of ALMs differ the offset to enable/disable is likely
270 * to be incorrect and enable/disable must be given as own
271 * reg address here.
272 */
273 bd_rtc->bd718xx_alm_block_start = BD71815_REG_RTC_ALM_START;
274 hour_reg = BD71815_REG_HOUR;
275 break;
276 case ROHM_CHIP_TYPE_BD71828:
277 bd_rtc->reg_time_start = BD71828_REG_RTC_START;
278 bd_rtc->bd718xx_alm_block_start = BD71828_REG_RTC_ALM_START;
279 hour_reg = BD71828_REG_RTC_HOUR;
280 break;
281 default:
282 dev_err(&pdev->dev, "Unknown chip\n");
283 return -ENOENT;
284 }
285
286 irq = platform_get_irq_byname(pdev, "bd70528-rtc-alm-0");
287
288 if (irq < 0)
289 return irq;
290
291 platform_set_drvdata(pdev, bd_rtc);
292
293 ret = regmap_read(bd_rtc->regmap, hour_reg, &hr);
294
295 if (ret) {
296 dev_err(&pdev->dev, "Failed to reag RTC clock\n");
297 return ret;
298 }
299
300 if (!(hr & BD70528_MASK_RTC_HOUR_24H)) {
301 struct rtc_time t;
302
303 ret = rtc_ops->read_time(&pdev->dev, &t);
304
305 if (!ret)
306 ret = rtc_ops->set_time(&pdev->dev, &t);
307
308 if (ret) {
309 dev_err(&pdev->dev,
310 "Setting 24H clock for RTC failed\n");
311 return ret;
312 }
313 }
314
315 device_set_wakeup_capable(&pdev->dev, true);
316 device_wakeup_enable(&pdev->dev);
317
318 rtc = devm_rtc_allocate_device(&pdev->dev);
319 if (IS_ERR(rtc)) {
320 dev_err(&pdev->dev, "RTC device creation failed\n");
321 return PTR_ERR(rtc);
322 }
323
324 rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
325 rtc->range_max = RTC_TIMESTAMP_END_2099;
326 rtc->ops = rtc_ops;
327
328 /* Request alarm IRQ prior to registerig the RTC */
329 ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, &alm_hndlr,
330 IRQF_ONESHOT, "bd70528-rtc", rtc);
331 if (ret)
332 return ret;
333
334 return devm_rtc_register_device(rtc);
335 }
336
337 static const struct platform_device_id bd718x7_rtc_id[] = {
338 { "bd71828-rtc", ROHM_CHIP_TYPE_BD71828 },
339 { "bd71815-rtc", ROHM_CHIP_TYPE_BD71815 },
340 { },
341 };
342 MODULE_DEVICE_TABLE(platform, bd718x7_rtc_id);
343
344 static struct platform_driver bd70528_rtc = {
345 .driver = {
346 .name = "bd70528-rtc"
347 },
348 .probe = bd70528_probe,
349 .id_table = bd718x7_rtc_id,
350 };
351
352 module_platform_driver(bd70528_rtc);
353
354 MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
355 MODULE_DESCRIPTION("ROHM BD71828 and BD71815 PMIC RTC driver");
356 MODULE_LICENSE("GPL");
357 MODULE_ALIAS("platform:bd70528-rtc");
358