1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * drivers/rtc/rtc-rc5t619.c
4 *
5 * Real time clock driver for RICOH RC5T619 power management chip.
6 *
7 * Copyright (C) 2019 Andreas Kemnade
8 */
9
10 #include <linux/kernel.h>
11 #include <linux/device.h>
12 #include <linux/errno.h>
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/mfd/rn5t618.h>
16 #include <linux/platform_device.h>
17 #include <linux/regmap.h>
18 #include <linux/bcd.h>
19 #include <linux/rtc.h>
20 #include <linux/slab.h>
21 #include <linux/irqdomain.h>
22
23 struct rc5t619_rtc {
24 int irq;
25 struct rtc_device *rtc;
26 struct rn5t618 *rn5t618;
27 };
28
29 #define CTRL1_ALARM_ENABLED 0x40
30 #define CTRL1_24HR 0x20
31 #define CTRL1_PERIODIC_MASK 0xf
32
33 #define CTRL2_PON 0x10
34 #define CTRL2_ALARM_STATUS 0x80
35 #define CTRL2_CTFG 0x4
36 #define CTRL2_CTC 0x1
37
38 #define MONTH_CENTFLAG 0x80
39 #define HOUR_PMFLAG 0x20
40 #define MDAY_DAL_EXT 0x80
41
rtc5t619_12hour_bcd2bin(uint8_t hour)42 static uint8_t rtc5t619_12hour_bcd2bin(uint8_t hour)
43 {
44 if (hour & HOUR_PMFLAG) {
45 hour = bcd2bin(hour & ~HOUR_PMFLAG);
46 return hour == 12 ? 12 : 12 + hour;
47 }
48
49 hour = bcd2bin(hour);
50 return hour == 12 ? 0 : hour;
51 }
52
rtc5t619_12hour_bin2bcd(uint8_t hour)53 static uint8_t rtc5t619_12hour_bin2bcd(uint8_t hour)
54 {
55 if (!hour)
56 return 0x12;
57
58 if (hour < 12)
59 return bin2bcd(hour);
60
61 if (hour == 12)
62 return 0x12 | HOUR_PMFLAG;
63
64 return bin2bcd(hour - 12) | HOUR_PMFLAG;
65 }
66
rc5t619_rtc_periodic_disable(struct device * dev)67 static int rc5t619_rtc_periodic_disable(struct device *dev)
68 {
69 struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
70 int err;
71
72 /* disable function */
73 err = regmap_update_bits(rtc->rn5t618->regmap,
74 RN5T618_RTC_CTRL1, CTRL1_PERIODIC_MASK, 0);
75 if (err < 0)
76 return err;
77
78 /* clear alarm flag and CTFG */
79 err = regmap_update_bits(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2,
80 CTRL2_ALARM_STATUS | CTRL2_CTFG | CTRL2_CTC,
81 0);
82 if (err < 0)
83 return err;
84
85 return 0;
86 }
87
88 /* things to be done once after power on */
rc5t619_rtc_pon_setup(struct device * dev)89 static int rc5t619_rtc_pon_setup(struct device *dev)
90 {
91 struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
92 int err;
93 unsigned int reg_data;
94
95 err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, ®_data);
96 if (err < 0)
97 return err;
98
99 /* clear VDET PON */
100 reg_data &= ~(CTRL2_PON | CTRL2_CTC | 0x4a); /* 0101-1011 */
101 reg_data |= 0x20; /* 0010-0000 */
102 err = regmap_write(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, reg_data);
103 if (err < 0)
104 return err;
105
106 /* clearing RTC Adjust register */
107 err = regmap_write(rtc->rn5t618->regmap, RN5T618_RTC_ADJUST, 0);
108 if (err)
109 return err;
110
111 return regmap_update_bits(rtc->rn5t618->regmap,
112 RN5T618_RTC_CTRL1,
113 CTRL1_24HR, CTRL1_24HR);
114 }
115
rc5t619_rtc_read_time(struct device * dev,struct rtc_time * tm)116 static int rc5t619_rtc_read_time(struct device *dev, struct rtc_time *tm)
117 {
118 struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
119 u8 buff[7];
120 int err;
121 int cent_flag;
122 unsigned int ctrl1;
123 unsigned int ctrl2;
124
125 err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &ctrl2);
126 if (err < 0)
127 return err;
128
129 if (ctrl2 & CTRL2_PON)
130 return -EINVAL;
131
132 err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &ctrl1);
133 if (err < 0)
134 return err;
135
136 err = regmap_bulk_read(rtc->rn5t618->regmap, RN5T618_RTC_SECONDS,
137 buff, sizeof(buff));
138 if (err < 0)
139 return err;
140
141 if (buff[5] & MONTH_CENTFLAG)
142 cent_flag = 1;
143 else
144 cent_flag = 0;
145
146 tm->tm_sec = bcd2bin(buff[0]);
147 tm->tm_min = bcd2bin(buff[1]);
148
149 if (ctrl1 & CTRL1_24HR)
150 tm->tm_hour = bcd2bin(buff[2]);
151 else
152 tm->tm_hour = rtc5t619_12hour_bcd2bin(buff[2]);
153
154 tm->tm_wday = bcd2bin(buff[3]);
155 tm->tm_mday = bcd2bin(buff[4]);
156 tm->tm_mon = bcd2bin(buff[5] & 0x1f) - 1; /* back to system 0-11 */
157 tm->tm_year = bcd2bin(buff[6]) + 100 * cent_flag;
158
159 return 0;
160 }
161
rc5t619_rtc_set_time(struct device * dev,struct rtc_time * tm)162 static int rc5t619_rtc_set_time(struct device *dev, struct rtc_time *tm)
163 {
164 struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
165 u8 buff[7];
166 int err;
167 int cent_flag;
168 unsigned int ctrl1;
169 unsigned int ctrl2;
170
171 err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &ctrl2);
172 if (err < 0)
173 return err;
174
175 if (ctrl2 & CTRL2_PON)
176 rc5t619_rtc_pon_setup(dev);
177
178 err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &ctrl1);
179 if (err < 0)
180 return err;
181
182 if (tm->tm_year >= 100)
183 cent_flag = 1;
184 else
185 cent_flag = 0;
186
187 buff[0] = bin2bcd(tm->tm_sec);
188 buff[1] = bin2bcd(tm->tm_min);
189
190 if (ctrl1 & CTRL1_24HR)
191 buff[2] = bin2bcd(tm->tm_hour);
192 else
193 buff[2] = rtc5t619_12hour_bin2bcd(tm->tm_hour);
194
195 buff[3] = bin2bcd(tm->tm_wday);
196 buff[4] = bin2bcd(tm->tm_mday);
197 buff[5] = bin2bcd(tm->tm_mon + 1); /* system set 0-11 */
198 buff[6] = bin2bcd(tm->tm_year - cent_flag * 100);
199
200 if (cent_flag)
201 buff[5] |= MONTH_CENTFLAG;
202
203 err = regmap_bulk_write(rtc->rn5t618->regmap, RN5T618_RTC_SECONDS,
204 buff, sizeof(buff));
205 if (err < 0) {
206 dev_err(dev, "failed to program new time: %d\n", err);
207 return err;
208 }
209
210 return 0;
211 }
212
213 /* 0-disable, 1-enable */
rc5t619_rtc_alarm_enable(struct device * dev,unsigned int enabled)214 static int rc5t619_rtc_alarm_enable(struct device *dev, unsigned int enabled)
215 {
216 struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
217
218 return regmap_update_bits(rtc->rn5t618->regmap,
219 RN5T618_RTC_CTRL1,
220 CTRL1_ALARM_ENABLED,
221 enabled ? CTRL1_ALARM_ENABLED : 0);
222 }
223
rc5t619_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alrm)224 static int rc5t619_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
225 {
226 struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
227 u8 buff[6];
228 unsigned int buff_cent;
229 int err;
230 int cent_flag;
231 unsigned int ctrl1;
232
233 err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &ctrl1);
234 if (err)
235 return err;
236
237 err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_MONTH, &buff_cent);
238 if (err < 0) {
239 dev_err(dev, "failed to read time: %d\n", err);
240 return err;
241 }
242
243 if (buff_cent & MONTH_CENTFLAG)
244 cent_flag = 1;
245 else
246 cent_flag = 0;
247
248 err = regmap_bulk_read(rtc->rn5t618->regmap, RN5T618_RTC_ALARM_Y_SEC,
249 buff, sizeof(buff));
250 if (err)
251 return err;
252
253 buff[3] = buff[3] & 0x3f;
254
255 alrm->time.tm_sec = bcd2bin(buff[0]);
256 alrm->time.tm_min = bcd2bin(buff[1]);
257
258 if (ctrl1 & CTRL1_24HR)
259 alrm->time.tm_hour = bcd2bin(buff[2]);
260 else
261 alrm->time.tm_hour = rtc5t619_12hour_bcd2bin(buff[2]);
262
263 alrm->time.tm_mday = bcd2bin(buff[3]);
264 alrm->time.tm_mon = bcd2bin(buff[4]) - 1;
265 alrm->time.tm_year = bcd2bin(buff[5]) + 100 * cent_flag;
266 alrm->enabled = !!(ctrl1 & CTRL1_ALARM_ENABLED);
267 dev_dbg(dev, "read alarm: %ptR\n", &alrm->time);
268
269 return 0;
270 }
271
rc5t619_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alrm)272 static int rc5t619_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
273 {
274 struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
275 u8 buff[6];
276 int err;
277 int cent_flag;
278 unsigned int ctrl1;
279
280 err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &ctrl1);
281 if (err)
282 return err;
283
284 err = rc5t619_rtc_alarm_enable(dev, 0);
285 if (err < 0)
286 return err;
287
288 if (rtc->irq == -1)
289 return -EINVAL;
290
291 if (alrm->enabled == 0)
292 return 0;
293
294 if (alrm->time.tm_year >= 100)
295 cent_flag = 1;
296 else
297 cent_flag = 0;
298
299 alrm->time.tm_mon += 1;
300 buff[0] = bin2bcd(alrm->time.tm_sec);
301 buff[1] = bin2bcd(alrm->time.tm_min);
302
303 if (ctrl1 & CTRL1_24HR)
304 buff[2] = bin2bcd(alrm->time.tm_hour);
305 else
306 buff[2] = rtc5t619_12hour_bin2bcd(alrm->time.tm_hour);
307
308 buff[3] = bin2bcd(alrm->time.tm_mday);
309 buff[4] = bin2bcd(alrm->time.tm_mon);
310 buff[5] = bin2bcd(alrm->time.tm_year - 100 * cent_flag);
311 buff[3] |= MDAY_DAL_EXT;
312
313 err = regmap_bulk_write(rtc->rn5t618->regmap, RN5T618_RTC_ALARM_Y_SEC,
314 buff, sizeof(buff));
315 if (err < 0)
316 return err;
317
318 return rc5t619_rtc_alarm_enable(dev, alrm->enabled);
319 }
320
321 static const struct rtc_class_ops rc5t619_rtc_ops = {
322 .read_time = rc5t619_rtc_read_time,
323 .set_time = rc5t619_rtc_set_time,
324 .set_alarm = rc5t619_rtc_set_alarm,
325 .read_alarm = rc5t619_rtc_read_alarm,
326 .alarm_irq_enable = rc5t619_rtc_alarm_enable,
327 };
328
rc5t619_rtc_alarm_flag_clr(struct device * dev)329 static int rc5t619_rtc_alarm_flag_clr(struct device *dev)
330 {
331 struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
332
333 /* clear alarm-D status bits.*/
334 return regmap_update_bits(rtc->rn5t618->regmap,
335 RN5T618_RTC_CTRL2,
336 CTRL2_ALARM_STATUS | CTRL2_CTC, 0);
337 }
338
rc5t619_rtc_irq(int irq,void * data)339 static irqreturn_t rc5t619_rtc_irq(int irq, void *data)
340 {
341 struct device *dev = data;
342 struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
343
344 rc5t619_rtc_alarm_flag_clr(dev);
345
346 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
347 return IRQ_HANDLED;
348 }
349
rc5t619_rtc_probe(struct platform_device * pdev)350 static int rc5t619_rtc_probe(struct platform_device *pdev)
351 {
352 struct device *dev = &pdev->dev;
353 struct rn5t618 *rn5t618 = dev_get_drvdata(pdev->dev.parent);
354 struct rc5t619_rtc *rtc;
355 unsigned int ctrl2;
356 int err;
357
358 rtc = devm_kzalloc(dev, sizeof(*rtc), GFP_KERNEL);
359 if (!rtc)
360 return -ENOMEM;
361
362 rtc->rn5t618 = rn5t618;
363
364 dev_set_drvdata(dev, rtc);
365 rtc->irq = -1;
366
367 if (rn5t618->irq_data)
368 rtc->irq = regmap_irq_get_virq(rn5t618->irq_data,
369 RN5T618_IRQ_RTC);
370
371 if (rtc->irq < 0)
372 rtc->irq = -1;
373
374 err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &ctrl2);
375 if (err < 0)
376 return err;
377
378 /* disable rtc periodic function */
379 err = rc5t619_rtc_periodic_disable(&pdev->dev);
380 if (err)
381 return err;
382
383 if (ctrl2 & CTRL2_PON) {
384 err = rc5t619_rtc_alarm_flag_clr(&pdev->dev);
385 if (err)
386 return err;
387 }
388
389 rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
390 if (IS_ERR(rtc->rtc)) {
391 err = PTR_ERR(rtc->rtc);
392 dev_err(dev, "RTC device register: err %d\n", err);
393 return err;
394 }
395
396 rtc->rtc->ops = &rc5t619_rtc_ops;
397 rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_1900;
398 rtc->rtc->range_max = RTC_TIMESTAMP_END_2099;
399
400 /* set interrupt and enable it */
401 if (rtc->irq != -1) {
402 err = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
403 rc5t619_rtc_irq,
404 IRQF_ONESHOT,
405 "rtc-rc5t619",
406 &pdev->dev);
407 if (err < 0) {
408 dev_err(&pdev->dev, "request IRQ:%d fail\n", rtc->irq);
409 rtc->irq = -1;
410
411 err = rc5t619_rtc_alarm_enable(&pdev->dev, 0);
412 if (err)
413 return err;
414
415 } else {
416 /* enable wake */
417 device_init_wakeup(&pdev->dev, 1);
418 enable_irq_wake(rtc->irq);
419 }
420 } else {
421 /* system don't want to using alarm interrupt, so close it */
422 err = rc5t619_rtc_alarm_enable(&pdev->dev, 0);
423 if (err)
424 return err;
425
426 dev_warn(&pdev->dev, "rc5t619 interrupt is disabled\n");
427 }
428
429 return devm_rtc_register_device(rtc->rtc);
430 }
431
432 static struct platform_driver rc5t619_rtc_driver = {
433 .driver = {
434 .name = "rc5t619-rtc",
435 },
436 .probe = rc5t619_rtc_probe,
437 };
438
439 module_platform_driver(rc5t619_rtc_driver);
440 MODULE_ALIAS("platform:rc5t619-rtc");
441 MODULE_DESCRIPTION("RICOH RC5T619 RTC driver");
442 MODULE_LICENSE("GPL");
443