Loading...
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.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#define PCF85063_REG_CTRL1_EXT_TEST BIT(7)
38
39#define PCF85063_REG_CTRL2 0x01
40#define PCF85063_CTRL2_AF BIT(6)
41#define PCF85063_CTRL2_AIE BIT(7)
42
43#define PCF85063_REG_OFFSET 0x02
44#define PCF85063_OFFSET_SIGN_BIT 6 /* 2's complement sign bit */
45#define PCF85063_OFFSET_MODE BIT(7)
46#define PCF85063_OFFSET_STEP0 4340
47#define PCF85063_OFFSET_STEP1 4069
48
49#define PCF85063_REG_CLKO_F_MASK 0x07 /* frequency mask */
50#define PCF85063_REG_CLKO_F_32768HZ 0x00
51#define PCF85063_REG_CLKO_F_OFF 0x07
52
53#define PCF85063_REG_RAM 0x03
54
55#define PCF85063_REG_SC 0x04 /* datetime */
56#define PCF85063_REG_SC_OS 0x80
57
58#define PCF85063_REG_ALM_S 0x0b
59#define PCF85063_AEN BIT(7)
60
61struct pcf85063_config {
62 struct regmap_config regmap;
63 unsigned has_alarms:1;
64 unsigned force_cap_7000:1;
65};
66
67struct pcf85063 {
68 struct rtc_device *rtc;
69 struct regmap *regmap;
70#ifdef CONFIG_COMMON_CLK
71 struct clk_hw clkout_hw;
72#endif
73};
74
75static int pcf85063_rtc_read_time(struct device *dev, struct rtc_time *tm)
76{
77 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
78 int rc;
79 u8 regs[7];
80
81 /*
82 * while reading, the time/date registers are blocked and not updated
83 * anymore until the access is finished. To not lose a second
84 * event, the access must be finished within one second. So, read all
85 * time/date registers in one turn.
86 */
87 rc = regmap_bulk_read(pcf85063->regmap, PCF85063_REG_SC, regs,
88 sizeof(regs));
89 if (rc)
90 return rc;
91
92 /* if the clock has lost its power it makes no sense to use its time */
93 if (regs[0] & PCF85063_REG_SC_OS) {
94 dev_warn(&pcf85063->rtc->dev, "Power loss detected, invalid time\n");
95 return -EINVAL;
96 }
97
98 tm->tm_sec = bcd2bin(regs[0] & 0x7F);
99 tm->tm_min = bcd2bin(regs[1] & 0x7F);
100 tm->tm_hour = bcd2bin(regs[2] & 0x3F); /* rtc hr 0-23 */
101 tm->tm_mday = bcd2bin(regs[3] & 0x3F);
102 tm->tm_wday = regs[4] & 0x07;
103 tm->tm_mon = bcd2bin(regs[5] & 0x1F) - 1; /* rtc mn 1-12 */
104 tm->tm_year = bcd2bin(regs[6]);
105 tm->tm_year += 100;
106
107 return 0;
108}
109
110static int pcf85063_rtc_set_time(struct device *dev, struct rtc_time *tm)
111{
112 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
113 int rc;
114 u8 regs[7];
115
116 /*
117 * to accurately set the time, reset the divider chain and keep it in
118 * reset state until all time/date registers are written
119 */
120 rc = regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL1,
121 PCF85063_REG_CTRL1_EXT_TEST |
122 PCF85063_REG_CTRL1_STOP,
123 PCF85063_REG_CTRL1_STOP);
124 if (rc)
125 return rc;
126
127 /* hours, minutes and seconds */
128 regs[0] = bin2bcd(tm->tm_sec) & 0x7F; /* clear OS flag */
129
130 regs[1] = bin2bcd(tm->tm_min);
131 regs[2] = bin2bcd(tm->tm_hour);
132
133 /* Day of month, 1 - 31 */
134 regs[3] = bin2bcd(tm->tm_mday);
135
136 /* Day, 0 - 6 */
137 regs[4] = tm->tm_wday & 0x07;
138
139 /* month, 1 - 12 */
140 regs[5] = bin2bcd(tm->tm_mon + 1);
141
142 /* year and century */
143 regs[6] = bin2bcd(tm->tm_year - 100);
144
145 /* write all registers at once */
146 rc = regmap_bulk_write(pcf85063->regmap, PCF85063_REG_SC,
147 regs, sizeof(regs));
148 if (rc)
149 return rc;
150
151 /*
152 * Write the control register as a separate action since the size of
153 * the register space is different between the PCF85063TP and
154 * PCF85063A devices. The rollover point can not be used.
155 */
156 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL1,
157 PCF85063_REG_CTRL1_STOP, 0);
158}
159
160static int pcf85063_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
161{
162 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
163 u8 buf[4];
164 unsigned int val;
165 int ret;
166
167 ret = regmap_bulk_read(pcf85063->regmap, PCF85063_REG_ALM_S,
168 buf, sizeof(buf));
169 if (ret)
170 return ret;
171
172 alrm->time.tm_sec = bcd2bin(buf[0] & 0x7f);
173 alrm->time.tm_min = bcd2bin(buf[1] & 0x7f);
174 alrm->time.tm_hour = bcd2bin(buf[2] & 0x3f);
175 alrm->time.tm_mday = bcd2bin(buf[3] & 0x3f);
176
177 ret = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &val);
178 if (ret)
179 return ret;
180
181 alrm->enabled = !!(val & PCF85063_CTRL2_AIE);
182
183 return 0;
184}
185
186static int pcf85063_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
187{
188 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
189 u8 buf[5];
190 int ret;
191
192 buf[0] = bin2bcd(alrm->time.tm_sec);
193 buf[1] = bin2bcd(alrm->time.tm_min);
194 buf[2] = bin2bcd(alrm->time.tm_hour);
195 buf[3] = bin2bcd(alrm->time.tm_mday);
196 buf[4] = PCF85063_AEN; /* Do not match on week day */
197
198 ret = regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
199 PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF, 0);
200 if (ret)
201 return ret;
202
203 ret = regmap_bulk_write(pcf85063->regmap, PCF85063_REG_ALM_S,
204 buf, sizeof(buf));
205 if (ret)
206 return ret;
207
208 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
209 PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF,
210 alrm->enabled ? PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF : PCF85063_CTRL2_AF);
211}
212
213static int pcf85063_rtc_alarm_irq_enable(struct device *dev,
214 unsigned int enabled)
215{
216 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
217
218 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
219 PCF85063_CTRL2_AIE,
220 enabled ? PCF85063_CTRL2_AIE : 0);
221}
222
223static irqreturn_t pcf85063_rtc_handle_irq(int irq, void *dev_id)
224{
225 struct pcf85063 *pcf85063 = dev_id;
226 unsigned int val;
227 int err;
228
229 err = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &val);
230 if (err)
231 return IRQ_NONE;
232
233 if (val & PCF85063_CTRL2_AF) {
234 rtc_update_irq(pcf85063->rtc, 1, RTC_IRQF | RTC_AF);
235 regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
236 PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF,
237 0);
238 return IRQ_HANDLED;
239 }
240
241 return IRQ_NONE;
242}
243
244static int pcf85063_read_offset(struct device *dev, long *offset)
245{
246 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
247 long val;
248 u32 reg;
249 int ret;
250
251 ret = regmap_read(pcf85063->regmap, PCF85063_REG_OFFSET, ®);
252 if (ret < 0)
253 return ret;
254
255 val = sign_extend32(reg & ~PCF85063_OFFSET_MODE,
256 PCF85063_OFFSET_SIGN_BIT);
257
258 if (reg & PCF85063_OFFSET_MODE)
259 *offset = val * PCF85063_OFFSET_STEP1;
260 else
261 *offset = val * PCF85063_OFFSET_STEP0;
262
263 return 0;
264}
265
266static int pcf85063_set_offset(struct device *dev, long offset)
267{
268 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
269 s8 mode0, mode1, reg;
270 unsigned int error0, error1;
271
272 if (offset > PCF85063_OFFSET_STEP0 * 63)
273 return -ERANGE;
274 if (offset < PCF85063_OFFSET_STEP0 * -64)
275 return -ERANGE;
276
277 mode0 = DIV_ROUND_CLOSEST(offset, PCF85063_OFFSET_STEP0);
278 mode1 = DIV_ROUND_CLOSEST(offset, PCF85063_OFFSET_STEP1);
279
280 error0 = abs(offset - (mode0 * PCF85063_OFFSET_STEP0));
281 error1 = abs(offset - (mode1 * PCF85063_OFFSET_STEP1));
282 if (mode1 > 63 || mode1 < -64 || error0 < error1)
283 reg = mode0 & ~PCF85063_OFFSET_MODE;
284 else
285 reg = mode1 | PCF85063_OFFSET_MODE;
286
287 return regmap_write(pcf85063->regmap, PCF85063_REG_OFFSET, reg);
288}
289
290static int pcf85063_ioctl(struct device *dev, unsigned int cmd,
291 unsigned long arg)
292{
293 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
294 int status, ret = 0;
295
296 switch (cmd) {
297 case RTC_VL_READ:
298 ret = regmap_read(pcf85063->regmap, PCF85063_REG_SC, &status);
299 if (ret < 0)
300 return ret;
301
302 status = (status & PCF85063_REG_SC_OS) ? RTC_VL_DATA_INVALID : 0;
303
304 return put_user(status, (unsigned int __user *)arg);
305
306 default:
307 return -ENOIOCTLCMD;
308 }
309}
310
311static const struct rtc_class_ops pcf85063_rtc_ops = {
312 .read_time = pcf85063_rtc_read_time,
313 .set_time = pcf85063_rtc_set_time,
314 .read_offset = pcf85063_read_offset,
315 .set_offset = pcf85063_set_offset,
316 .read_alarm = pcf85063_rtc_read_alarm,
317 .set_alarm = pcf85063_rtc_set_alarm,
318 .alarm_irq_enable = pcf85063_rtc_alarm_irq_enable,
319 .ioctl = pcf85063_ioctl,
320};
321
322static int pcf85063_nvmem_read(void *priv, unsigned int offset,
323 void *val, size_t bytes)
324{
325 return regmap_read(priv, PCF85063_REG_RAM, val);
326}
327
328static int pcf85063_nvmem_write(void *priv, unsigned int offset,
329 void *val, size_t bytes)
330{
331 return regmap_write(priv, PCF85063_REG_RAM, *(u8 *)val);
332}
333
334static int pcf85063_load_capacitance(struct pcf85063 *pcf85063,
335 const struct device_node *np,
336 unsigned int force_cap)
337{
338 u32 load = 7000;
339 u8 reg = 0;
340
341 if (force_cap)
342 load = force_cap;
343 else
344 of_property_read_u32(np, "quartz-load-femtofarads", &load);
345
346 switch (load) {
347 default:
348 dev_warn(&pcf85063->rtc->dev, "Unknown quartz-load-femtofarads value: %d. Assuming 7000",
349 load);
350 fallthrough;
351 case 7000:
352 break;
353 case 12500:
354 reg = PCF85063_REG_CTRL1_CAP_SEL;
355 break;
356 }
357
358 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL1,
359 PCF85063_REG_CTRL1_CAP_SEL, reg);
360}
361
362#ifdef CONFIG_COMMON_CLK
363/*
364 * Handling of the clkout
365 */
366
367#define clkout_hw_to_pcf85063(_hw) container_of(_hw, struct pcf85063, clkout_hw)
368
369static int clkout_rates[] = {
370 32768,
371 16384,
372 8192,
373 4096,
374 2048,
375 1024,
376 1,
377 0
378};
379
380static unsigned long pcf85063_clkout_recalc_rate(struct clk_hw *hw,
381 unsigned long parent_rate)
382{
383 struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw);
384 unsigned int buf;
385 int ret = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &buf);
386
387 if (ret < 0)
388 return 0;
389
390 buf &= PCF85063_REG_CLKO_F_MASK;
391 return clkout_rates[buf];
392}
393
394static long pcf85063_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
395 unsigned long *prate)
396{
397 int i;
398
399 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
400 if (clkout_rates[i] <= rate)
401 return clkout_rates[i];
402
403 return 0;
404}
405
406static int pcf85063_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
407 unsigned long parent_rate)
408{
409 struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw);
410 int i;
411
412 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
413 if (clkout_rates[i] == rate)
414 return regmap_update_bits(pcf85063->regmap,
415 PCF85063_REG_CTRL2,
416 PCF85063_REG_CLKO_F_MASK, i);
417
418 return -EINVAL;
419}
420
421static int pcf85063_clkout_control(struct clk_hw *hw, bool enable)
422{
423 struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw);
424 unsigned int buf;
425 int ret;
426
427 ret = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &buf);
428 if (ret < 0)
429 return ret;
430 buf &= PCF85063_REG_CLKO_F_MASK;
431
432 if (enable) {
433 if (buf == PCF85063_REG_CLKO_F_OFF)
434 buf = PCF85063_REG_CLKO_F_32768HZ;
435 else
436 return 0;
437 } else {
438 if (buf != PCF85063_REG_CLKO_F_OFF)
439 buf = PCF85063_REG_CLKO_F_OFF;
440 else
441 return 0;
442 }
443
444 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
445 PCF85063_REG_CLKO_F_MASK, buf);
446}
447
448static int pcf85063_clkout_prepare(struct clk_hw *hw)
449{
450 return pcf85063_clkout_control(hw, 1);
451}
452
453static void pcf85063_clkout_unprepare(struct clk_hw *hw)
454{
455 pcf85063_clkout_control(hw, 0);
456}
457
458static int pcf85063_clkout_is_prepared(struct clk_hw *hw)
459{
460 struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw);
461 unsigned int buf;
462 int ret = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &buf);
463
464 if (ret < 0)
465 return 0;
466
467 return (buf & PCF85063_REG_CLKO_F_MASK) != PCF85063_REG_CLKO_F_OFF;
468}
469
470static const struct clk_ops pcf85063_clkout_ops = {
471 .prepare = pcf85063_clkout_prepare,
472 .unprepare = pcf85063_clkout_unprepare,
473 .is_prepared = pcf85063_clkout_is_prepared,
474 .recalc_rate = pcf85063_clkout_recalc_rate,
475 .round_rate = pcf85063_clkout_round_rate,
476 .set_rate = pcf85063_clkout_set_rate,
477};
478
479static struct clk *pcf85063_clkout_register_clk(struct pcf85063 *pcf85063)
480{
481 struct clk *clk;
482 struct clk_init_data init;
483 struct device_node *node = pcf85063->rtc->dev.parent->of_node;
484 struct device_node *fixed_clock;
485
486 fixed_clock = of_get_child_by_name(node, "clock");
487 if (fixed_clock) {
488 /*
489 * skip registering square wave clock when a fixed
490 * clock has been registered. The fixed clock is
491 * registered automatically when being referenced.
492 */
493 of_node_put(fixed_clock);
494 return NULL;
495 }
496
497 init.name = "pcf85063-clkout";
498 init.ops = &pcf85063_clkout_ops;
499 init.flags = 0;
500 init.parent_names = NULL;
501 init.num_parents = 0;
502 pcf85063->clkout_hw.init = &init;
503
504 /* optional override of the clockname */
505 of_property_read_string(node, "clock-output-names", &init.name);
506
507 /* register the clock */
508 clk = devm_clk_register(&pcf85063->rtc->dev, &pcf85063->clkout_hw);
509
510 if (!IS_ERR(clk))
511 of_clk_add_provider(node, of_clk_src_simple_get, clk);
512
513 return clk;
514}
515#endif
516
517static const struct pcf85063_config config_pcf85063 = {
518 .regmap = {
519 .reg_bits = 8,
520 .val_bits = 8,
521 .max_register = 0x0a,
522 },
523};
524
525static const struct pcf85063_config config_pcf85063tp = {
526 .regmap = {
527 .reg_bits = 8,
528 .val_bits = 8,
529 .max_register = 0x0a,
530 },
531};
532
533static const struct pcf85063_config config_pcf85063a = {
534 .regmap = {
535 .reg_bits = 8,
536 .val_bits = 8,
537 .max_register = 0x11,
538 },
539 .has_alarms = 1,
540};
541
542static const struct pcf85063_config config_rv8263 = {
543 .regmap = {
544 .reg_bits = 8,
545 .val_bits = 8,
546 .max_register = 0x11,
547 },
548 .has_alarms = 1,
549 .force_cap_7000 = 1,
550};
551
552static int pcf85063_probe(struct i2c_client *client)
553{
554 struct pcf85063 *pcf85063;
555 unsigned int tmp;
556 int err;
557 const struct pcf85063_config *config;
558 struct nvmem_config nvmem_cfg = {
559 .name = "pcf85063_nvram",
560 .reg_read = pcf85063_nvmem_read,
561 .reg_write = pcf85063_nvmem_write,
562 .type = NVMEM_TYPE_BATTERY_BACKED,
563 .size = 1,
564 };
565
566 dev_dbg(&client->dev, "%s\n", __func__);
567
568 pcf85063 = devm_kzalloc(&client->dev, sizeof(struct pcf85063),
569 GFP_KERNEL);
570 if (!pcf85063)
571 return -ENOMEM;
572
573 config = i2c_get_match_data(client);
574 if (!config)
575 return -ENODEV;
576
577 pcf85063->regmap = devm_regmap_init_i2c(client, &config->regmap);
578 if (IS_ERR(pcf85063->regmap))
579 return PTR_ERR(pcf85063->regmap);
580
581 i2c_set_clientdata(client, pcf85063);
582
583 err = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL1, &tmp);
584 if (err) {
585 dev_err(&client->dev, "RTC chip is not present\n");
586 return err;
587 }
588
589 pcf85063->rtc = devm_rtc_allocate_device(&client->dev);
590 if (IS_ERR(pcf85063->rtc))
591 return PTR_ERR(pcf85063->rtc);
592
593 err = pcf85063_load_capacitance(pcf85063, client->dev.of_node,
594 config->force_cap_7000 ? 7000 : 0);
595 if (err < 0)
596 dev_warn(&client->dev, "failed to set xtal load capacitance: %d",
597 err);
598
599 pcf85063->rtc->ops = &pcf85063_rtc_ops;
600 pcf85063->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
601 pcf85063->rtc->range_max = RTC_TIMESTAMP_END_2099;
602 set_bit(RTC_FEATURE_ALARM_RES_2S, pcf85063->rtc->features);
603 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, pcf85063->rtc->features);
604 clear_bit(RTC_FEATURE_ALARM, pcf85063->rtc->features);
605
606 if (config->has_alarms && client->irq > 0) {
607 unsigned long irqflags = IRQF_TRIGGER_LOW;
608
609 if (dev_fwnode(&client->dev))
610 irqflags = 0;
611
612 err = devm_request_threaded_irq(&client->dev, client->irq,
613 NULL, pcf85063_rtc_handle_irq,
614 irqflags | IRQF_ONESHOT,
615 "pcf85063", pcf85063);
616 if (err) {
617 dev_warn(&pcf85063->rtc->dev,
618 "unable to request IRQ, alarms disabled\n");
619 } else {
620 set_bit(RTC_FEATURE_ALARM, pcf85063->rtc->features);
621 device_init_wakeup(&client->dev, true);
622 err = dev_pm_set_wake_irq(&client->dev, client->irq);
623 if (err)
624 dev_err(&pcf85063->rtc->dev,
625 "failed to enable irq wake\n");
626 }
627 }
628
629 nvmem_cfg.priv = pcf85063->regmap;
630 devm_rtc_nvmem_register(pcf85063->rtc, &nvmem_cfg);
631
632#ifdef CONFIG_COMMON_CLK
633 /* register clk in common clk framework */
634 pcf85063_clkout_register_clk(pcf85063);
635#endif
636
637 return devm_rtc_register_device(pcf85063->rtc);
638}
639
640static const struct i2c_device_id pcf85063_ids[] = {
641 { "pca85073a", .driver_data = (kernel_ulong_t)&config_pcf85063a },
642 { "pcf85063", .driver_data = (kernel_ulong_t)&config_pcf85063 },
643 { "pcf85063tp", .driver_data = (kernel_ulong_t)&config_pcf85063tp },
644 { "pcf85063a", .driver_data = (kernel_ulong_t)&config_pcf85063a },
645 { "rv8263", .driver_data = (kernel_ulong_t)&config_rv8263 },
646 {}
647};
648MODULE_DEVICE_TABLE(i2c, pcf85063_ids);
649
650#ifdef CONFIG_OF
651static const struct of_device_id pcf85063_of_match[] = {
652 { .compatible = "nxp,pca85073a", .data = &config_pcf85063a },
653 { .compatible = "nxp,pcf85063", .data = &config_pcf85063 },
654 { .compatible = "nxp,pcf85063tp", .data = &config_pcf85063tp },
655 { .compatible = "nxp,pcf85063a", .data = &config_pcf85063a },
656 { .compatible = "microcrystal,rv8263", .data = &config_rv8263 },
657 {}
658};
659MODULE_DEVICE_TABLE(of, pcf85063_of_match);
660#endif
661
662static struct i2c_driver pcf85063_driver = {
663 .driver = {
664 .name = "rtc-pcf85063",
665 .of_match_table = of_match_ptr(pcf85063_of_match),
666 },
667 .probe = pcf85063_probe,
668 .id_table = pcf85063_ids,
669};
670
671module_i2c_driver(pcf85063_driver);
672
673MODULE_AUTHOR("Søren Andersen <san@rosetechnology.dk>");
674MODULE_DESCRIPTION("PCF85063 RTC driver");
675MODULE_LICENSE("GPL");
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
60struct pcf85063_config {
61 struct regmap_config regmap;
62 unsigned has_alarms:1;
63 unsigned force_cap_7000:1;
64};
65
66struct 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
74static 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
109static 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
158static 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
184static 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
211static 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
221static 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
242static 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, ®);
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
264static 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
288static 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
309static 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
320static 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
326static 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
332static 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
367static int clkout_rates[] = {
368 32768,
369 16384,
370 8192,
371 4096,
372 2048,
373 1024,
374 1,
375 0
376};
377
378static 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
392static 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
404static 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
419static 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
446static int pcf85063_clkout_prepare(struct clk_hw *hw)
447{
448 return pcf85063_clkout_control(hw, 1);
449}
450
451static void pcf85063_clkout_unprepare(struct clk_hw *hw)
452{
453 pcf85063_clkout_control(hw, 0);
454}
455
456static 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
468static 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
477static 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
503static const struct pcf85063_config pcf85063tp_config = {
504 .regmap = {
505 .reg_bits = 8,
506 .val_bits = 8,
507 .max_register = 0x0a,
508 },
509};
510
511static 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
594static 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
603static 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
613static 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};
620MODULE_DEVICE_TABLE(of, pcf85063_of_match);
621#endif
622
623static 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
631module_i2c_driver(pcf85063_driver);
632
633MODULE_AUTHOR("Søren Andersen <san@rosetechnology.dk>");
634MODULE_DESCRIPTION("PCF85063 RTC driver");
635MODULE_LICENSE("GPL");