1 // SPDX-License-Identifier: GPL-2.0
3 * An I2C driver for the PCF85063 RTC
4 * Copyright 2014 Rose Technology
7 * Maintainers: http://www.nslu2-linux.org/
9 * Copyright (C) 2019 Micro Crystal AG
12 #include <linux/i2c.h>
13 #include <linux/bcd.h>
14 #include <linux/rtc.h>
15 #include <linux/module.h>
16 #include <linux/of_device.h>
17 #include <linux/pm_wakeirq.h>
18 #include <linux/regmap.h>
21 * Information for this driver was pulled from the following datasheets.
23 * http://www.nxp.com/documents/data_sheet/PCF85063A.pdf
24 * http://www.nxp.com/documents/data_sheet/PCF85063TP.pdf
26 * PCF85063A -- Rev. 6 — 18 November 2015
27 * PCF85063TP -- Rev. 4 — 6 May 2015
29 * https://www.microcrystal.com/fileadmin/Media/Products/RTC/App.Manual/RV-8263-C7_App-Manual.pdf
30 * RV8263 -- Rev. 1.0 — January 2019
33 #define PCF85063_REG_CTRL1 0x00 /* status */
34 #define PCF85063_REG_CTRL1_CAP_SEL BIT(0)
35 #define PCF85063_REG_CTRL1_STOP BIT(5)
37 #define PCF85063_REG_CTRL2 0x01
38 #define PCF85063_CTRL2_AF BIT(6)
39 #define PCF85063_CTRL2_AIE BIT(7)
41 #define PCF85063_REG_OFFSET 0x02
42 #define PCF85063_OFFSET_SIGN_BIT 6 /* 2's complement sign bit */
43 #define PCF85063_OFFSET_MODE BIT(7)
44 #define PCF85063_OFFSET_STEP0 4340
45 #define PCF85063_OFFSET_STEP1 4069
47 #define PCF85063_REG_RAM 0x03
49 #define PCF85063_REG_SC 0x04 /* datetime */
50 #define PCF85063_REG_SC_OS 0x80
52 #define PCF85063_REG_ALM_S 0x0b
53 #define PCF85063_AEN BIT(7)
55 struct pcf85063_config {
56 struct regmap_config regmap;
57 unsigned has_alarms:1;
58 unsigned force_cap_7000:1;
62 struct rtc_device *rtc;
63 struct regmap *regmap;
66 static int pcf85063_rtc_read_time(struct device *dev, struct rtc_time *tm)
68 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
73 * while reading, the time/date registers are blocked and not updated
74 * anymore until the access is finished. To not lose a second
75 * event, the access must be finished within one second. So, read all
76 * time/date registers in one turn.
78 rc = regmap_bulk_read(pcf85063->regmap, PCF85063_REG_SC, regs,
83 /* if the clock has lost its power it makes no sense to use its time */
84 if (regs[0] & PCF85063_REG_SC_OS) {
85 dev_warn(&pcf85063->rtc->dev, "Power loss detected, invalid time\n");
89 tm->tm_sec = bcd2bin(regs[0] & 0x7F);
90 tm->tm_min = bcd2bin(regs[1] & 0x7F);
91 tm->tm_hour = bcd2bin(regs[2] & 0x3F); /* rtc hr 0-23 */
92 tm->tm_mday = bcd2bin(regs[3] & 0x3F);
93 tm->tm_wday = regs[4] & 0x07;
94 tm->tm_mon = bcd2bin(regs[5] & 0x1F) - 1; /* rtc mn 1-12 */
95 tm->tm_year = bcd2bin(regs[6]);
101 static int pcf85063_rtc_set_time(struct device *dev, struct rtc_time *tm)
103 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
108 * to accurately set the time, reset the divider chain and keep it in
109 * reset state until all time/date registers are written
111 rc = regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL1,
112 PCF85063_REG_CTRL1_STOP,
113 PCF85063_REG_CTRL1_STOP);
117 /* hours, minutes and seconds */
118 regs[0] = bin2bcd(tm->tm_sec) & 0x7F; /* clear OS flag */
120 regs[1] = bin2bcd(tm->tm_min);
121 regs[2] = bin2bcd(tm->tm_hour);
123 /* Day of month, 1 - 31 */
124 regs[3] = bin2bcd(tm->tm_mday);
127 regs[4] = tm->tm_wday & 0x07;
130 regs[5] = bin2bcd(tm->tm_mon + 1);
132 /* year and century */
133 regs[6] = bin2bcd(tm->tm_year - 100);
135 /* write all registers at once */
136 rc = regmap_bulk_write(pcf85063->regmap, PCF85063_REG_SC,
142 * Write the control register as a separate action since the size of
143 * the register space is different between the PCF85063TP and
144 * PCF85063A devices. The rollover point can not be used.
146 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL1,
147 PCF85063_REG_CTRL1_STOP, 0);
150 static int pcf85063_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
152 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
157 ret = regmap_bulk_read(pcf85063->regmap, PCF85063_REG_ALM_S,
162 alrm->time.tm_sec = bcd2bin(buf[0]);
163 alrm->time.tm_min = bcd2bin(buf[1]);
164 alrm->time.tm_hour = bcd2bin(buf[2]);
165 alrm->time.tm_mday = bcd2bin(buf[3]);
167 ret = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &val);
171 alrm->enabled = !!(val & PCF85063_CTRL2_AIE);
176 static int pcf85063_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
178 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
182 buf[0] = bin2bcd(alrm->time.tm_sec);
183 buf[1] = bin2bcd(alrm->time.tm_min);
184 buf[2] = bin2bcd(alrm->time.tm_hour);
185 buf[3] = bin2bcd(alrm->time.tm_mday);
186 buf[4] = PCF85063_AEN; /* Do not match on week day */
188 ret = regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
189 PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF, 0);
193 ret = regmap_bulk_write(pcf85063->regmap, PCF85063_REG_ALM_S,
198 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
199 PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF,
200 alrm->enabled ? PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF : PCF85063_CTRL2_AF);
203 static int pcf85063_rtc_alarm_irq_enable(struct device *dev,
204 unsigned int enabled)
206 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
208 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
210 enabled ? PCF85063_CTRL2_AIE : 0);
213 static irqreturn_t pcf85063_rtc_handle_irq(int irq, void *dev_id)
215 struct pcf85063 *pcf85063 = dev_id;
219 err = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &val);
223 if (val & PCF85063_CTRL2_AF) {
224 rtc_update_irq(pcf85063->rtc, 1, RTC_IRQF | RTC_AF);
225 regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
226 PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF,
234 static int pcf85063_read_offset(struct device *dev, long *offset)
236 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
241 ret = regmap_read(pcf85063->regmap, PCF85063_REG_OFFSET, ®);
245 val = sign_extend32(reg & ~PCF85063_OFFSET_MODE,
246 PCF85063_OFFSET_SIGN_BIT);
248 if (reg & PCF85063_OFFSET_MODE)
249 *offset = val * PCF85063_OFFSET_STEP1;
251 *offset = val * PCF85063_OFFSET_STEP0;
256 static int pcf85063_set_offset(struct device *dev, long offset)
258 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
259 s8 mode0, mode1, reg;
260 unsigned int error0, error1;
262 if (offset > PCF85063_OFFSET_STEP0 * 63)
264 if (offset < PCF85063_OFFSET_STEP0 * -64)
267 mode0 = DIV_ROUND_CLOSEST(offset, PCF85063_OFFSET_STEP0);
268 mode1 = DIV_ROUND_CLOSEST(offset, PCF85063_OFFSET_STEP1);
270 error0 = abs(offset - (mode0 * PCF85063_OFFSET_STEP0));
271 error1 = abs(offset - (mode1 * PCF85063_OFFSET_STEP1));
272 if (mode1 > 63 || mode1 < -64 || error0 < error1)
273 reg = mode0 & ~PCF85063_OFFSET_MODE;
275 reg = mode1 | PCF85063_OFFSET_MODE;
277 return regmap_write(pcf85063->regmap, PCF85063_REG_OFFSET, reg);
280 static int pcf85063_ioctl(struct device *dev, unsigned int cmd,
283 struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
288 ret = regmap_read(pcf85063->regmap, PCF85063_REG_SC, &status);
292 if (status & PCF85063_REG_SC_OS)
293 dev_warn(&pcf85063->rtc->dev, "Voltage low, data loss detected.\n");
295 status &= PCF85063_REG_SC_OS;
297 if (copy_to_user((void __user *)arg, &status, sizeof(int)))
303 ret = regmap_update_bits(pcf85063->regmap, PCF85063_REG_SC,
304 PCF85063_REG_SC_OS, 0);
313 static const struct rtc_class_ops pcf85063_rtc_ops = {
314 .read_time = pcf85063_rtc_read_time,
315 .set_time = pcf85063_rtc_set_time,
316 .read_offset = pcf85063_read_offset,
317 .set_offset = pcf85063_set_offset,
318 .ioctl = pcf85063_ioctl,
321 static const struct rtc_class_ops pcf85063_rtc_ops_alarm = {
322 .read_time = pcf85063_rtc_read_time,
323 .set_time = pcf85063_rtc_set_time,
324 .read_offset = pcf85063_read_offset,
325 .set_offset = pcf85063_set_offset,
326 .read_alarm = pcf85063_rtc_read_alarm,
327 .set_alarm = pcf85063_rtc_set_alarm,
328 .alarm_irq_enable = pcf85063_rtc_alarm_irq_enable,
329 .ioctl = pcf85063_ioctl,
332 static int pcf85063_nvmem_read(void *priv, unsigned int offset,
333 void *val, size_t bytes)
335 return regmap_read(priv, PCF85063_REG_RAM, val);
338 static int pcf85063_nvmem_write(void *priv, unsigned int offset,
339 void *val, size_t bytes)
341 return regmap_write(priv, PCF85063_REG_RAM, *(u8 *)val);
344 static int pcf85063_load_capacitance(struct pcf85063 *pcf85063,
345 const struct device_node *np,
346 unsigned int force_cap)
354 of_property_read_u32(np, "quartz-load-femtofarads", &load);
358 dev_warn(&pcf85063->rtc->dev, "Unknown quartz-load-femtofarads value: %d. Assuming 7000",
364 reg = PCF85063_REG_CTRL1_CAP_SEL;
368 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL1,
369 PCF85063_REG_CTRL1_CAP_SEL, reg);
372 static const struct pcf85063_config pcf85063a_config = {
376 .max_register = 0x11,
381 static const struct pcf85063_config pcf85063tp_config = {
385 .max_register = 0x0a,
389 static const struct pcf85063_config rv8263_config = {
393 .max_register = 0x11,
399 static int pcf85063_probe(struct i2c_client *client)
401 struct pcf85063 *pcf85063;
404 const struct pcf85063_config *config = &pcf85063tp_config;
405 const void *data = of_device_get_match_data(&client->dev);
406 struct nvmem_config nvmem_cfg = {
407 .name = "pcf85063_nvram",
408 .reg_read = pcf85063_nvmem_read,
409 .reg_write = pcf85063_nvmem_write,
410 .type = NVMEM_TYPE_BATTERY_BACKED,
414 dev_dbg(&client->dev, "%s\n", __func__);
416 pcf85063 = devm_kzalloc(&client->dev, sizeof(struct pcf85063),
424 pcf85063->regmap = devm_regmap_init_i2c(client, &config->regmap);
425 if (IS_ERR(pcf85063->regmap))
426 return PTR_ERR(pcf85063->regmap);
428 i2c_set_clientdata(client, pcf85063);
430 err = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL1, &tmp);
432 dev_err(&client->dev, "RTC chip is not present\n");
436 pcf85063->rtc = devm_rtc_allocate_device(&client->dev);
437 if (IS_ERR(pcf85063->rtc))
438 return PTR_ERR(pcf85063->rtc);
440 err = pcf85063_load_capacitance(pcf85063, client->dev.of_node,
441 config->force_cap_7000 ? 7000 : 0);
443 dev_warn(&client->dev, "failed to set xtal load capacitance: %d",
446 pcf85063->rtc->ops = &pcf85063_rtc_ops;
447 pcf85063->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
448 pcf85063->rtc->range_max = RTC_TIMESTAMP_END_2099;
449 pcf85063->rtc->uie_unsupported = 1;
451 if (config->has_alarms && client->irq > 0) {
452 err = devm_request_threaded_irq(&client->dev, client->irq,
453 NULL, pcf85063_rtc_handle_irq,
454 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
455 "pcf85063", pcf85063);
457 dev_warn(&pcf85063->rtc->dev,
458 "unable to request IRQ, alarms disabled\n");
460 pcf85063->rtc->ops = &pcf85063_rtc_ops_alarm;
461 device_init_wakeup(&client->dev, true);
462 err = dev_pm_set_wake_irq(&client->dev, client->irq);
464 dev_err(&pcf85063->rtc->dev,
465 "failed to enable irq wake\n");
469 nvmem_cfg.priv = pcf85063->regmap;
470 rtc_nvmem_register(pcf85063->rtc, &nvmem_cfg);
472 return rtc_register_device(pcf85063->rtc);
476 static const struct of_device_id pcf85063_of_match[] = {
477 { .compatible = "nxp,pcf85063", .data = &pcf85063tp_config },
478 { .compatible = "nxp,pcf85063tp", .data = &pcf85063tp_config },
479 { .compatible = "nxp,pcf85063a", .data = &pcf85063a_config },
480 { .compatible = "microcrystal,rv8263", .data = &rv8263_config },
483 MODULE_DEVICE_TABLE(of, pcf85063_of_match);
486 static struct i2c_driver pcf85063_driver = {
488 .name = "rtc-pcf85063",
489 .of_match_table = of_match_ptr(pcf85063_of_match),
491 .probe_new = pcf85063_probe,
494 module_i2c_driver(pcf85063_driver);
497 MODULE_DESCRIPTION("PCF85063 RTC driver");
498 MODULE_LICENSE("GPL");