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 | |
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 | |
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 | |
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(map: rtc->rn5t618->regmap, |
74 | RN5T618_RTC_CTRL1, CTRL1_PERIODIC_MASK, val: 0); |
75 | if (err < 0) |
76 | return err; |
77 | |
78 | /* clear alarm flag and CTFG */ |
79 | err = regmap_update_bits(map: rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, |
80 | CTRL2_ALARM_STATUS | CTRL2_CTFG | CTRL2_CTC, |
81 | val: 0); |
82 | if (err < 0) |
83 | return err; |
84 | |
85 | return 0; |
86 | } |
87 | |
88 | /* things to be done once after power on */ |
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(map: rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, val: ®_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(map: rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, val: reg_data); |
103 | if (err < 0) |
104 | return err; |
105 | |
106 | /* clearing RTC Adjust register */ |
107 | err = regmap_write(map: rtc->rn5t618->regmap, RN5T618_RTC_ADJUST, val: 0); |
108 | if (err) |
109 | return err; |
110 | |
111 | return regmap_update_bits(map: rtc->rn5t618->regmap, |
112 | RN5T618_RTC_CTRL1, |
113 | CTRL1_24HR, CTRL1_24HR); |
114 | } |
115 | |
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(map: rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, val: &ctrl2); |
126 | if (err < 0) |
127 | return err; |
128 | |
129 | if (ctrl2 & CTRL2_PON) |
130 | return -EINVAL; |
131 | |
132 | err = regmap_read(map: rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, val: &ctrl1); |
133 | if (err < 0) |
134 | return err; |
135 | |
136 | err = regmap_bulk_read(map: rtc->rn5t618->regmap, RN5T618_RTC_SECONDS, |
137 | val: buff, val_count: 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(hour: 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 | |
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(map: rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, val: &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(map: rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, val: &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(hour: 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(map: rtc->rn5t618->regmap, RN5T618_RTC_SECONDS, |
204 | val: buff, val_count: 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 */ |
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(map: rtc->rn5t618->regmap, |
219 | RN5T618_RTC_CTRL1, |
220 | CTRL1_ALARM_ENABLED, |
221 | val: enabled ? CTRL1_ALARM_ENABLED : 0); |
222 | } |
223 | |
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(map: rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, val: &ctrl1); |
234 | if (err) |
235 | return err; |
236 | |
237 | err = regmap_read(map: rtc->rn5t618->regmap, RN5T618_RTC_MONTH, val: &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(map: rtc->rn5t618->regmap, RN5T618_RTC_ALARM_Y_SEC, |
249 | val: buff, val_count: 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(hour: 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 | |
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(map: rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, val: &ctrl1); |
281 | if (err) |
282 | return err; |
283 | |
284 | err = rc5t619_rtc_alarm_enable(dev, enabled: 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(hour: 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(map: rtc->rn5t618->regmap, RN5T618_RTC_ALARM_Y_SEC, |
314 | val: buff, val_count: sizeof(buff)); |
315 | if (err < 0) |
316 | return err; |
317 | |
318 | return rc5t619_rtc_alarm_enable(dev, enabled: 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 | |
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(map: rtc->rn5t618->regmap, |
335 | RN5T618_RTC_CTRL2, |
336 | CTRL2_ALARM_STATUS | CTRL2_CTC, val: 0); |
337 | } |
338 | |
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->rtc, num: 1, RTC_IRQF | RTC_AF); |
347 | return IRQ_HANDLED; |
348 | } |
349 | |
350 | static int rc5t619_rtc_probe(struct platform_device *pdev) |
351 | { |
352 | struct device *dev = &pdev->dev; |
353 | struct rn5t618 *rn5t618 = dev_get_drvdata(dev: pdev->dev.parent); |
354 | struct rc5t619_rtc *rtc; |
355 | unsigned int ctrl2; |
356 | int err; |
357 | |
358 | rtc = devm_kzalloc(dev, size: sizeof(*rtc), GFP_KERNEL); |
359 | if (!rtc) |
360 | return -ENOMEM; |
361 | |
362 | rtc->rn5t618 = rn5t618; |
363 | |
364 | dev_set_drvdata(dev, data: rtc); |
365 | rtc->irq = -1; |
366 | |
367 | if (rn5t618->irq_data) |
368 | rtc->irq = regmap_irq_get_virq(data: rn5t618->irq_data, |
369 | irq: RN5T618_IRQ_RTC); |
370 | |
371 | if (rtc->irq < 0) |
372 | rtc->irq = -1; |
373 | |
374 | err = regmap_read(map: rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, val: &ctrl2); |
375 | if (err < 0) |
376 | return err; |
377 | |
378 | /* disable rtc periodic function */ |
379 | err = rc5t619_rtc_periodic_disable(dev: &pdev->dev); |
380 | if (err) |
381 | return err; |
382 | |
383 | if (ctrl2 & CTRL2_PON) { |
384 | err = rc5t619_rtc_alarm_flag_clr(dev: &pdev->dev); |
385 | if (err) |
386 | return err; |
387 | } |
388 | |
389 | rtc->rtc = devm_rtc_allocate_device(dev: &pdev->dev); |
390 | if (IS_ERR(ptr: rtc->rtc)) { |
391 | err = PTR_ERR(ptr: 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(dev: &pdev->dev, irq: rtc->irq, NULL, |
403 | thread_fn: rc5t619_rtc_irq, |
404 | IRQF_ONESHOT, |
405 | devname: "rtc-rc5t619" , |
406 | dev_id: &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(dev: &pdev->dev, enabled: 0); |
412 | if (err) |
413 | return err; |
414 | |
415 | } else { |
416 | /* enable wake */ |
417 | device_init_wakeup(dev: &pdev->dev, enable: 1); |
418 | enable_irq_wake(irq: rtc->irq); |
419 | } |
420 | } else { |
421 | /* system don't want to using alarm interrupt, so close it */ |
422 | err = rc5t619_rtc_alarm_enable(dev: &pdev->dev, enabled: 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 | |