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[mirror_ubuntu-jammy-kernel.git] / drivers / rtc / rtc-pcf85063.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * An I2C driver for the PCF85063 RTC
4 * Copyright 2014 Rose Technology
5 *
6 * Author: Søren Andersen <san@rosetechnology.dk>
7 * Maintainers: http://www.nslu2-linux.org/
8 *
9 * Copyright (C) 2019 Micro Crystal AG
10 * Author: Alexandre Belloni <alexandre.belloni@bootlin.com>
11 */
12 #include <linux/clk-provider.h>
13 #include <linux/i2c.h>
14 #include <linux/bcd.h>
15 #include <linux/rtc.h>
16 #include <linux/module.h>
17 #include <linux/of_device.h>
18 #include <linux/pm_wakeirq.h>
19 #include <linux/regmap.h>
20
21 /*
22 * Information for this driver was pulled from the following datasheets.
23 *
24 * https://www.nxp.com/docs/en/data-sheet/PCF85063A.pdf
25 * https://www.nxp.com/docs/en/data-sheet/PCF85063TP.pdf
26 *
27 * PCF85063A -- Rev. 7 — 30 March 2018
28 * PCF85063TP -- Rev. 4 — 6 May 2015
29 *
30 * https://www.microcrystal.com/fileadmin/Media/Products/RTC/App.Manual/RV-8263-C7_App-Manual.pdf
31 * RV8263 -- Rev. 1.0 — January 2019
32 */
33
34 #define PCF85063_REG_CTRL1 0x00 /* status */
35 #define PCF85063_REG_CTRL1_CAP_SEL BIT(0)
36 #define PCF85063_REG_CTRL1_STOP BIT(5)
37
38 #define PCF85063_REG_CTRL2 0x01
39 #define PCF85063_CTRL2_AF BIT(6)
40 #define PCF85063_CTRL2_AIE BIT(7)
41
42 #define PCF85063_REG_OFFSET 0x02
43 #define PCF85063_OFFSET_SIGN_BIT 6 /* 2's complement sign bit */
44 #define PCF85063_OFFSET_MODE BIT(7)
45 #define PCF85063_OFFSET_STEP0 4340
46 #define PCF85063_OFFSET_STEP1 4069
47
48 #define PCF85063_REG_CLKO_F_MASK 0x07 /* frequency mask */
49 #define PCF85063_REG_CLKO_F_32768HZ 0x00
50 #define PCF85063_REG_CLKO_F_OFF 0x07
51
52 #define PCF85063_REG_RAM 0x03
53
54 #define PCF85063_REG_SC 0x04 /* datetime */
55 #define PCF85063_REG_SC_OS 0x80
56
57 #define PCF85063_REG_ALM_S 0x0b
58 #define PCF85063_AEN BIT(7)
59
60 struct pcf85063_config {
61 struct regmap_config regmap;
62 unsigned has_alarms:1;
63 unsigned force_cap_7000:1;
64 };
65
66 struct pcf85063 {
67 struct rtc_device *rtc;
68 struct regmap *regmap;
69 #ifdef CONFIG_COMMON_CLK
70 struct clk_hw clkout_hw;
71 #endif
72 };
73
74 static int pcf85063_rtc_read_time(struct device *dev, struct rtc_time *tm)
75 {
76 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
77 int rc;
78 u8 regs[7];
79
80 /*
81 * while reading, the time/date registers are blocked and not updated
82 * anymore until the access is finished. To not lose a second
83 * event, the access must be finished within one second. So, read all
84 * time/date registers in one turn.
85 */
86 rc = regmap_bulk_read(pcf85063->regmap, PCF85063_REG_SC, regs,
87 sizeof(regs));
88 if (rc)
89 return rc;
90
91 /* if the clock has lost its power it makes no sense to use its time */
92 if (regs[0] & PCF85063_REG_SC_OS) {
93 dev_warn(&pcf85063->rtc->dev, "Power loss detected, invalid time\n");
94 return -EINVAL;
95 }
96
97 tm->tm_sec = bcd2bin(regs[0] & 0x7F);
98 tm->tm_min = bcd2bin(regs[1] & 0x7F);
99 tm->tm_hour = bcd2bin(regs[2] & 0x3F); /* rtc hr 0-23 */
100 tm->tm_mday = bcd2bin(regs[3] & 0x3F);
101 tm->tm_wday = regs[4] & 0x07;
102 tm->tm_mon = bcd2bin(regs[5] & 0x1F) - 1; /* rtc mn 1-12 */
103 tm->tm_year = bcd2bin(regs[6]);
104 tm->tm_year += 100;
105
106 return 0;
107 }
108
109 static int pcf85063_rtc_set_time(struct device *dev, struct rtc_time *tm)
110 {
111 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
112 int rc;
113 u8 regs[7];
114
115 /*
116 * to accurately set the time, reset the divider chain and keep it in
117 * reset state until all time/date registers are written
118 */
119 rc = regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL1,
120 PCF85063_REG_CTRL1_STOP,
121 PCF85063_REG_CTRL1_STOP);
122 if (rc)
123 return rc;
124
125 /* hours, minutes and seconds */
126 regs[0] = bin2bcd(tm->tm_sec) & 0x7F; /* clear OS flag */
127
128 regs[1] = bin2bcd(tm->tm_min);
129 regs[2] = bin2bcd(tm->tm_hour);
130
131 /* Day of month, 1 - 31 */
132 regs[3] = bin2bcd(tm->tm_mday);
133
134 /* Day, 0 - 6 */
135 regs[4] = tm->tm_wday & 0x07;
136
137 /* month, 1 - 12 */
138 regs[5] = bin2bcd(tm->tm_mon + 1);
139
140 /* year and century */
141 regs[6] = bin2bcd(tm->tm_year - 100);
142
143 /* write all registers at once */
144 rc = regmap_bulk_write(pcf85063->regmap, PCF85063_REG_SC,
145 regs, sizeof(regs));
146 if (rc)
147 return rc;
148
149 /*
150 * Write the control register as a separate action since the size of
151 * the register space is different between the PCF85063TP and
152 * PCF85063A devices. The rollover point can not be used.
153 */
154 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL1,
155 PCF85063_REG_CTRL1_STOP, 0);
156 }
157
158 static int pcf85063_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
159 {
160 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
161 u8 buf[4];
162 unsigned int val;
163 int ret;
164
165 ret = regmap_bulk_read(pcf85063->regmap, PCF85063_REG_ALM_S,
166 buf, sizeof(buf));
167 if (ret)
168 return ret;
169
170 alrm->time.tm_sec = bcd2bin(buf[0]);
171 alrm->time.tm_min = bcd2bin(buf[1]);
172 alrm->time.tm_hour = bcd2bin(buf[2]);
173 alrm->time.tm_mday = bcd2bin(buf[3]);
174
175 ret = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &val);
176 if (ret)
177 return ret;
178
179 alrm->enabled = !!(val & PCF85063_CTRL2_AIE);
180
181 return 0;
182 }
183
184 static int pcf85063_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
185 {
186 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
187 u8 buf[5];
188 int ret;
189
190 buf[0] = bin2bcd(alrm->time.tm_sec);
191 buf[1] = bin2bcd(alrm->time.tm_min);
192 buf[2] = bin2bcd(alrm->time.tm_hour);
193 buf[3] = bin2bcd(alrm->time.tm_mday);
194 buf[4] = PCF85063_AEN; /* Do not match on week day */
195
196 ret = regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
197 PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF, 0);
198 if (ret)
199 return ret;
200
201 ret = regmap_bulk_write(pcf85063->regmap, PCF85063_REG_ALM_S,
202 buf, sizeof(buf));
203 if (ret)
204 return ret;
205
206 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
207 PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF,
208 alrm->enabled ? PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF : PCF85063_CTRL2_AF);
209 }
210
211 static int pcf85063_rtc_alarm_irq_enable(struct device *dev,
212 unsigned int enabled)
213 {
214 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
215
216 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
217 PCF85063_CTRL2_AIE,
218 enabled ? PCF85063_CTRL2_AIE : 0);
219 }
220
221 static irqreturn_t pcf85063_rtc_handle_irq(int irq, void *dev_id)
222 {
223 struct pcf85063 *pcf85063 = dev_id;
224 unsigned int val;
225 int err;
226
227 err = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &val);
228 if (err)
229 return IRQ_NONE;
230
231 if (val & PCF85063_CTRL2_AF) {
232 rtc_update_irq(pcf85063->rtc, 1, RTC_IRQF | RTC_AF);
233 regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
234 PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF,
235 0);
236 return IRQ_HANDLED;
237 }
238
239 return IRQ_NONE;
240 }
241
242 static int pcf85063_read_offset(struct device *dev, long *offset)
243 {
244 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
245 long val;
246 u32 reg;
247 int ret;
248
249 ret = regmap_read(pcf85063->regmap, PCF85063_REG_OFFSET, &reg);
250 if (ret < 0)
251 return ret;
252
253 val = sign_extend32(reg & ~PCF85063_OFFSET_MODE,
254 PCF85063_OFFSET_SIGN_BIT);
255
256 if (reg & PCF85063_OFFSET_MODE)
257 *offset = val * PCF85063_OFFSET_STEP1;
258 else
259 *offset = val * PCF85063_OFFSET_STEP0;
260
261 return 0;
262 }
263
264 static int pcf85063_set_offset(struct device *dev, long offset)
265 {
266 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
267 s8 mode0, mode1, reg;
268 unsigned int error0, error1;
269
270 if (offset > PCF85063_OFFSET_STEP0 * 63)
271 return -ERANGE;
272 if (offset < PCF85063_OFFSET_STEP0 * -64)
273 return -ERANGE;
274
275 mode0 = DIV_ROUND_CLOSEST(offset, PCF85063_OFFSET_STEP0);
276 mode1 = DIV_ROUND_CLOSEST(offset, PCF85063_OFFSET_STEP1);
277
278 error0 = abs(offset - (mode0 * PCF85063_OFFSET_STEP0));
279 error1 = abs(offset - (mode1 * PCF85063_OFFSET_STEP1));
280 if (mode1 > 63 || mode1 < -64 || error0 < error1)
281 reg = mode0 & ~PCF85063_OFFSET_MODE;
282 else
283 reg = mode1 | PCF85063_OFFSET_MODE;
284
285 return regmap_write(pcf85063->regmap, PCF85063_REG_OFFSET, reg);
286 }
287
288 static int pcf85063_ioctl(struct device *dev, unsigned int cmd,
289 unsigned long arg)
290 {
291 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
292 int status, ret = 0;
293
294 switch (cmd) {
295 case RTC_VL_READ:
296 ret = regmap_read(pcf85063->regmap, PCF85063_REG_SC, &status);
297 if (ret < 0)
298 return ret;
299
300 status = status & PCF85063_REG_SC_OS ? RTC_VL_DATA_INVALID : 0;
301
302 return put_user(status, (unsigned int __user *)arg);
303
304 default:
305 return -ENOIOCTLCMD;
306 }
307 }
308
309 static const struct rtc_class_ops pcf85063_rtc_ops = {
310 .read_time = pcf85063_rtc_read_time,
311 .set_time = pcf85063_rtc_set_time,
312 .read_offset = pcf85063_read_offset,
313 .set_offset = pcf85063_set_offset,
314 .read_alarm = pcf85063_rtc_read_alarm,
315 .set_alarm = pcf85063_rtc_set_alarm,
316 .alarm_irq_enable = pcf85063_rtc_alarm_irq_enable,
317 .ioctl = pcf85063_ioctl,
318 };
319
320 static int pcf85063_nvmem_read(void *priv, unsigned int offset,
321 void *val, size_t bytes)
322 {
323 return regmap_read(priv, PCF85063_REG_RAM, val);
324 }
325
326 static int pcf85063_nvmem_write(void *priv, unsigned int offset,
327 void *val, size_t bytes)
328 {
329 return regmap_write(priv, PCF85063_REG_RAM, *(u8 *)val);
330 }
331
332 static int pcf85063_load_capacitance(struct pcf85063 *pcf85063,
333 const struct device_node *np,
334 unsigned int force_cap)
335 {
336 u32 load = 7000;
337 u8 reg = 0;
338
339 if (force_cap)
340 load = force_cap;
341 else
342 of_property_read_u32(np, "quartz-load-femtofarads", &load);
343
344 switch (load) {
345 default:
346 dev_warn(&pcf85063->rtc->dev, "Unknown quartz-load-femtofarads value: %d. Assuming 7000",
347 load);
348 fallthrough;
349 case 7000:
350 break;
351 case 12500:
352 reg = PCF85063_REG_CTRL1_CAP_SEL;
353 break;
354 }
355
356 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL1,
357 PCF85063_REG_CTRL1_CAP_SEL, reg);
358 }
359
360 #ifdef CONFIG_COMMON_CLK
361 /*
362 * Handling of the clkout
363 */
364
365 #define clkout_hw_to_pcf85063(_hw) container_of(_hw, struct pcf85063, clkout_hw)
366
367 static int clkout_rates[] = {
368 32768,
369 16384,
370 8192,
371 4096,
372 2048,
373 1024,
374 1,
375 0
376 };
377
378 static unsigned long pcf85063_clkout_recalc_rate(struct clk_hw *hw,
379 unsigned long parent_rate)
380 {
381 struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw);
382 unsigned int buf;
383 int ret = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &buf);
384
385 if (ret < 0)
386 return 0;
387
388 buf &= PCF85063_REG_CLKO_F_MASK;
389 return clkout_rates[buf];
390 }
391
392 static long pcf85063_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
393 unsigned long *prate)
394 {
395 int i;
396
397 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
398 if (clkout_rates[i] <= rate)
399 return clkout_rates[i];
400
401 return 0;
402 }
403
404 static int pcf85063_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
405 unsigned long parent_rate)
406 {
407 struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw);
408 int i;
409
410 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
411 if (clkout_rates[i] == rate)
412 return regmap_update_bits(pcf85063->regmap,
413 PCF85063_REG_CTRL2,
414 PCF85063_REG_CLKO_F_MASK, i);
415
416 return -EINVAL;
417 }
418
419 static int pcf85063_clkout_control(struct clk_hw *hw, bool enable)
420 {
421 struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw);
422 unsigned int buf;
423 int ret;
424
425 ret = regmap_read(pcf85063->regmap, PCF85063_REG_OFFSET, &buf);
426 if (ret < 0)
427 return ret;
428 buf &= PCF85063_REG_CLKO_F_MASK;
429
430 if (enable) {
431 if (buf == PCF85063_REG_CLKO_F_OFF)
432 buf = PCF85063_REG_CLKO_F_32768HZ;
433 else
434 return 0;
435 } else {
436 if (buf != PCF85063_REG_CLKO_F_OFF)
437 buf = PCF85063_REG_CLKO_F_OFF;
438 else
439 return 0;
440 }
441
442 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
443 PCF85063_REG_CLKO_F_MASK, buf);
444 }
445
446 static int pcf85063_clkout_prepare(struct clk_hw *hw)
447 {
448 return pcf85063_clkout_control(hw, 1);
449 }
450
451 static void pcf85063_clkout_unprepare(struct clk_hw *hw)
452 {
453 pcf85063_clkout_control(hw, 0);
454 }
455
456 static int pcf85063_clkout_is_prepared(struct clk_hw *hw)
457 {
458 struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw);
459 unsigned int buf;
460 int ret = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &buf);
461
462 if (ret < 0)
463 return 0;
464
465 return (buf & PCF85063_REG_CLKO_F_MASK) != PCF85063_REG_CLKO_F_OFF;
466 }
467
468 static const struct clk_ops pcf85063_clkout_ops = {
469 .prepare = pcf85063_clkout_prepare,
470 .unprepare = pcf85063_clkout_unprepare,
471 .is_prepared = pcf85063_clkout_is_prepared,
472 .recalc_rate = pcf85063_clkout_recalc_rate,
473 .round_rate = pcf85063_clkout_round_rate,
474 .set_rate = pcf85063_clkout_set_rate,
475 };
476
477 static struct clk *pcf85063_clkout_register_clk(struct pcf85063 *pcf85063)
478 {
479 struct clk *clk;
480 struct clk_init_data init;
481 struct device_node *node = pcf85063->rtc->dev.parent->of_node;
482
483 init.name = "pcf85063-clkout";
484 init.ops = &pcf85063_clkout_ops;
485 init.flags = 0;
486 init.parent_names = NULL;
487 init.num_parents = 0;
488 pcf85063->clkout_hw.init = &init;
489
490 /* optional override of the clockname */
491 of_property_read_string(node, "clock-output-names", &init.name);
492
493 /* register the clock */
494 clk = devm_clk_register(&pcf85063->rtc->dev, &pcf85063->clkout_hw);
495
496 if (!IS_ERR(clk))
497 of_clk_add_provider(node, of_clk_src_simple_get, clk);
498
499 return clk;
500 }
501 #endif
502
503 static const struct pcf85063_config pcf85063tp_config = {
504 .regmap = {
505 .reg_bits = 8,
506 .val_bits = 8,
507 .max_register = 0x0a,
508 },
509 };
510
511 static int pcf85063_probe(struct i2c_client *client)
512 {
513 struct pcf85063 *pcf85063;
514 unsigned int tmp;
515 int err;
516 const struct pcf85063_config *config = &pcf85063tp_config;
517 const void *data = of_device_get_match_data(&client->dev);
518 struct nvmem_config nvmem_cfg = {
519 .name = "pcf85063_nvram",
520 .reg_read = pcf85063_nvmem_read,
521 .reg_write = pcf85063_nvmem_write,
522 .type = NVMEM_TYPE_BATTERY_BACKED,
523 .size = 1,
524 };
525
526 dev_dbg(&client->dev, "%s\n", __func__);
527
528 pcf85063 = devm_kzalloc(&client->dev, sizeof(struct pcf85063),
529 GFP_KERNEL);
530 if (!pcf85063)
531 return -ENOMEM;
532
533 if (data)
534 config = data;
535
536 pcf85063->regmap = devm_regmap_init_i2c(client, &config->regmap);
537 if (IS_ERR(pcf85063->regmap))
538 return PTR_ERR(pcf85063->regmap);
539
540 i2c_set_clientdata(client, pcf85063);
541
542 err = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL1, &tmp);
543 if (err) {
544 dev_err(&client->dev, "RTC chip is not present\n");
545 return err;
546 }
547
548 pcf85063->rtc = devm_rtc_allocate_device(&client->dev);
549 if (IS_ERR(pcf85063->rtc))
550 return PTR_ERR(pcf85063->rtc);
551
552 err = pcf85063_load_capacitance(pcf85063, client->dev.of_node,
553 config->force_cap_7000 ? 7000 : 0);
554 if (err < 0)
555 dev_warn(&client->dev, "failed to set xtal load capacitance: %d",
556 err);
557
558 pcf85063->rtc->ops = &pcf85063_rtc_ops;
559 pcf85063->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
560 pcf85063->rtc->range_max = RTC_TIMESTAMP_END_2099;
561 pcf85063->rtc->uie_unsupported = 1;
562 clear_bit(RTC_FEATURE_ALARM, pcf85063->rtc->features);
563
564 if (config->has_alarms && client->irq > 0) {
565 err = devm_request_threaded_irq(&client->dev, client->irq,
566 NULL, pcf85063_rtc_handle_irq,
567 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
568 "pcf85063", pcf85063);
569 if (err) {
570 dev_warn(&pcf85063->rtc->dev,
571 "unable to request IRQ, alarms disabled\n");
572 } else {
573 set_bit(RTC_FEATURE_ALARM, pcf85063->rtc->features);
574 device_init_wakeup(&client->dev, true);
575 err = dev_pm_set_wake_irq(&client->dev, client->irq);
576 if (err)
577 dev_err(&pcf85063->rtc->dev,
578 "failed to enable irq wake\n");
579 }
580 }
581
582 nvmem_cfg.priv = pcf85063->regmap;
583 devm_rtc_nvmem_register(pcf85063->rtc, &nvmem_cfg);
584
585 #ifdef CONFIG_COMMON_CLK
586 /* register clk in common clk framework */
587 pcf85063_clkout_register_clk(pcf85063);
588 #endif
589
590 return devm_rtc_register_device(pcf85063->rtc);
591 }
592
593 #ifdef CONFIG_OF
594 static const struct pcf85063_config pcf85063a_config = {
595 .regmap = {
596 .reg_bits = 8,
597 .val_bits = 8,
598 .max_register = 0x11,
599 },
600 .has_alarms = 1,
601 };
602
603 static const struct pcf85063_config rv8263_config = {
604 .regmap = {
605 .reg_bits = 8,
606 .val_bits = 8,
607 .max_register = 0x11,
608 },
609 .has_alarms = 1,
610 .force_cap_7000 = 1,
611 };
612
613 static const struct of_device_id pcf85063_of_match[] = {
614 { .compatible = "nxp,pcf85063", .data = &pcf85063tp_config },
615 { .compatible = "nxp,pcf85063tp", .data = &pcf85063tp_config },
616 { .compatible = "nxp,pcf85063a", .data = &pcf85063a_config },
617 { .compatible = "microcrystal,rv8263", .data = &rv8263_config },
618 {}
619 };
620 MODULE_DEVICE_TABLE(of, pcf85063_of_match);
621 #endif
622
623 static struct i2c_driver pcf85063_driver = {
624 .driver = {
625 .name = "rtc-pcf85063",
626 .of_match_table = of_match_ptr(pcf85063_of_match),
627 },
628 .probe_new = pcf85063_probe,
629 };
630
631 module_i2c_driver(pcf85063_driver);
632
633 MODULE_AUTHOR("Søren Andersen <san@rosetechnology.dk>");
634 MODULE_DESCRIPTION("PCF85063 RTC driver");
635 MODULE_LICENSE("GPL");