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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * An I2C driver for the Philips PCF8563 RTC4 * Copyright 2005-06 Tower Technologies5 *6 * Author: Alessandro Zummo <a.zummo@towertech.it>7 * Maintainers: http://www.nslu2-linux.org/8 *9 * based on the other drivers in this same directory.10 *11 * https://www.nxp.com/docs/en/data-sheet/PCF8563.pdf12 */13 14#include <linux/clk-provider.h>15#include <linux/i2c.h>16#include <linux/bcd.h>17#include <linux/rtc.h>18#include <linux/slab.h>19#include <linux/module.h>20#include <linux/of.h>21#include <linux/err.h>22 23#define PCF8563_REG_ST1 0x00 /* status */24#define PCF8563_REG_ST2 0x0125#define PCF8563_BIT_AIE BIT(1)26#define PCF8563_BIT_AF BIT(3)27#define PCF8563_BITS_ST2_N (7 << 5)28 29#define PCF8563_REG_SC 0x02 /* datetime */30#define PCF8563_REG_MN 0x0331#define PCF8563_REG_HR 0x0432#define PCF8563_REG_DM 0x0533#define PCF8563_REG_DW 0x0634#define PCF8563_REG_MO 0x0735#define PCF8563_REG_YR 0x0836 37#define PCF8563_REG_AMN 0x09 /* alarm */38 39#define PCF8563_REG_CLKO 0x0D /* clock out */40#define PCF8563_REG_CLKO_FE 0x80 /* clock out enabled */41#define PCF8563_REG_CLKO_F_MASK 0x03 /* frequenc mask */42#define PCF8563_REG_CLKO_F_32768HZ 0x0043#define PCF8563_REG_CLKO_F_1024HZ 0x0144#define PCF8563_REG_CLKO_F_32HZ 0x0245#define PCF8563_REG_CLKO_F_1HZ 0x0346 47#define PCF8563_REG_TMRC 0x0E /* timer control */48#define PCF8563_TMRC_ENABLE BIT(7)49#define PCF8563_TMRC_4096 050#define PCF8563_TMRC_64 151#define PCF8563_TMRC_1 252#define PCF8563_TMRC_1_60 353#define PCF8563_TMRC_MASK 354 55#define PCF8563_REG_TMR 0x0F /* timer */56 57#define PCF8563_SC_LV 0x80 /* low voltage */58#define PCF8563_MO_C 0x80 /* century */59 60static struct i2c_driver pcf8563_driver;61 62struct pcf8563 {63 struct rtc_device *rtc;64 /*65 * The meaning of MO_C bit varies by the chip type.66 * From PCF8563 datasheet: this bit is toggled when the years67 * register overflows from 99 to 0068 * 0 indicates the century is 20xx69 * 1 indicates the century is 19xx70 * From RTC8564 datasheet: this bit indicates change of71 * century. When the year digit data overflows from 99 to 00,72 * this bit is set. By presetting it to 0 while still in the73 * 20th century, it will be set in year 2000, ...74 * There seems no reliable way to know how the system use this75 * bit. So let's do it heuristically, assuming we are live in76 * 1970...2069.77 */78 int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */79 80 struct i2c_client *client;81#ifdef CONFIG_COMMON_CLK82 struct clk_hw clkout_hw;83#endif84};85 86static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg,87 unsigned char length, unsigned char *buf)88{89 struct i2c_msg msgs[] = {90 {/* setup read ptr */91 .addr = client->addr,92 .len = 1,93 .buf = ®,94 },95 {96 .addr = client->addr,97 .flags = I2C_M_RD,98 .len = length,99 .buf = buf100 },101 };102 103 if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {104 dev_err(&client->dev, "%s: read error\n", __func__);105 return -EIO;106 }107 108 return 0;109}110 111static int pcf8563_write_block_data(struct i2c_client *client,112 unsigned char reg, unsigned char length,113 unsigned char *buf)114{115 int i, err;116 117 for (i = 0; i < length; i++) {118 unsigned char data[2] = { reg + i, buf[i] };119 120 err = i2c_master_send(client, data, sizeof(data));121 if (err != sizeof(data)) {122 dev_err(&client->dev,123 "%s: err=%d addr=%02x, data=%02x\n",124 __func__, err, data[0], data[1]);125 return -EIO;126 }127 }128 129 return 0;130}131 132static int pcf8563_set_alarm_mode(struct i2c_client *client, bool on)133{134 unsigned char buf;135 int err;136 137 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);138 if (err < 0)139 return err;140 141 if (on)142 buf |= PCF8563_BIT_AIE;143 else144 buf &= ~PCF8563_BIT_AIE;145 146 buf &= ~(PCF8563_BIT_AF | PCF8563_BITS_ST2_N);147 148 err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);149 if (err < 0) {150 dev_err(&client->dev, "%s: write error\n", __func__);151 return -EIO;152 }153 154 return 0;155}156 157static int pcf8563_get_alarm_mode(struct i2c_client *client, unsigned char *en,158 unsigned char *pen)159{160 unsigned char buf;161 int err;162 163 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);164 if (err)165 return err;166 167 if (en)168 *en = !!(buf & PCF8563_BIT_AIE);169 if (pen)170 *pen = !!(buf & PCF8563_BIT_AF);171 172 return 0;173}174 175static irqreturn_t pcf8563_irq(int irq, void *dev_id)176{177 struct pcf8563 *pcf8563 = i2c_get_clientdata(dev_id);178 int err;179 char pending;180 181 err = pcf8563_get_alarm_mode(pcf8563->client, NULL, &pending);182 if (err)183 return IRQ_NONE;184 185 if (pending) {186 rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF);187 pcf8563_set_alarm_mode(pcf8563->client, 1);188 return IRQ_HANDLED;189 }190 191 return IRQ_NONE;192}193 194/*195 * In the routines that deal directly with the pcf8563 hardware, we use196 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.197 */198static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)199{200 struct i2c_client *client = to_i2c_client(dev);201 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);202 unsigned char buf[9];203 int err;204 205 err = pcf8563_read_block_data(client, PCF8563_REG_ST1, 9, buf);206 if (err)207 return err;208 209 if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {210 dev_err(&client->dev,211 "low voltage detected, date/time is not reliable.\n");212 return -EINVAL;213 }214 215 dev_dbg(&client->dev,216 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "217 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",218 __func__,219 buf[0], buf[1], buf[2], buf[3],220 buf[4], buf[5], buf[6], buf[7],221 buf[8]);222 223 224 tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);225 tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);226 tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */227 tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);228 tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;229 tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */230 tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]) + 100;231 /* detect the polarity heuristically. see note above. */232 pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?233 (tm->tm_year >= 100) : (tm->tm_year < 100);234 235 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "236 "mday=%d, mon=%d, year=%d, wday=%d\n",237 __func__,238 tm->tm_sec, tm->tm_min, tm->tm_hour,239 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);240 241 return 0;242}243 244static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)245{246 struct i2c_client *client = to_i2c_client(dev);247 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);248 unsigned char buf[9];249 250 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "251 "mday=%d, mon=%d, year=%d, wday=%d\n",252 __func__,253 tm->tm_sec, tm->tm_min, tm->tm_hour,254 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);255 256 /* hours, minutes and seconds */257 buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);258 buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);259 buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);260 261 buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);262 263 /* month, 1 - 12 */264 buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);265 266 /* year and century */267 buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year - 100);268 if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))269 buf[PCF8563_REG_MO] |= PCF8563_MO_C;270 271 buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;272 273 return pcf8563_write_block_data(client, PCF8563_REG_SC,274 9 - PCF8563_REG_SC, buf + PCF8563_REG_SC);275}276 277static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)278{279 struct i2c_client *client = to_i2c_client(dev);280 int ret;281 282 switch (cmd) {283 case RTC_VL_READ:284 ret = i2c_smbus_read_byte_data(client, PCF8563_REG_SC);285 if (ret < 0)286 return ret;287 288 return put_user(ret & PCF8563_SC_LV ? RTC_VL_DATA_INVALID : 0,289 (unsigned int __user *)arg);290 default:291 return -ENOIOCTLCMD;292 }293}294 295static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)296{297 struct i2c_client *client = to_i2c_client(dev);298 unsigned char buf[4];299 int err;300 301 err = pcf8563_read_block_data(client, PCF8563_REG_AMN, 4, buf);302 if (err)303 return err;304 305 dev_dbg(&client->dev,306 "%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n",307 __func__, buf[0], buf[1], buf[2], buf[3]);308 309 tm->time.tm_sec = 0;310 tm->time.tm_min = bcd2bin(buf[0] & 0x7F);311 tm->time.tm_hour = bcd2bin(buf[1] & 0x3F);312 tm->time.tm_mday = bcd2bin(buf[2] & 0x3F);313 tm->time.tm_wday = bcd2bin(buf[3] & 0x7);314 315 err = pcf8563_get_alarm_mode(client, &tm->enabled, &tm->pending);316 if (err < 0)317 return err;318 319 dev_dbg(&client->dev, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d,"320 " enabled=%d, pending=%d\n", __func__, tm->time.tm_min,321 tm->time.tm_hour, tm->time.tm_mday, tm->time.tm_wday,322 tm->enabled, tm->pending);323 324 return 0;325}326 327static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)328{329 struct i2c_client *client = to_i2c_client(dev);330 unsigned char buf[4];331 int err;332 333 buf[0] = bin2bcd(tm->time.tm_min);334 buf[1] = bin2bcd(tm->time.tm_hour);335 buf[2] = bin2bcd(tm->time.tm_mday);336 buf[3] = tm->time.tm_wday & 0x07;337 338 err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf);339 if (err)340 return err;341 342 return pcf8563_set_alarm_mode(client, !!tm->enabled);343}344 345static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)346{347 dev_dbg(dev, "%s: en=%d\n", __func__, enabled);348 return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled);349}350 351#ifdef CONFIG_COMMON_CLK352/*353 * Handling of the clkout354 */355 356#define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw)357 358static const int clkout_rates[] = {359 32768,360 1024,361 32,362 1,363};364 365static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw,366 unsigned long parent_rate)367{368 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);369 struct i2c_client *client = pcf8563->client;370 unsigned char buf;371 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);372 373 if (ret < 0)374 return 0;375 376 buf &= PCF8563_REG_CLKO_F_MASK;377 return clkout_rates[buf];378}379 380static long pcf8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,381 unsigned long *prate)382{383 int i;384 385 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)386 if (clkout_rates[i] <= rate)387 return clkout_rates[i];388 389 return 0;390}391 392static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,393 unsigned long parent_rate)394{395 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);396 struct i2c_client *client = pcf8563->client;397 unsigned char buf;398 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);399 int i;400 401 if (ret < 0)402 return ret;403 404 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)405 if (clkout_rates[i] == rate) {406 buf &= ~PCF8563_REG_CLKO_F_MASK;407 buf |= i;408 ret = pcf8563_write_block_data(client,409 PCF8563_REG_CLKO, 1,410 &buf);411 return ret;412 }413 414 return -EINVAL;415}416 417static int pcf8563_clkout_control(struct clk_hw *hw, bool enable)418{419 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);420 struct i2c_client *client = pcf8563->client;421 unsigned char buf;422 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);423 424 if (ret < 0)425 return ret;426 427 if (enable)428 buf |= PCF8563_REG_CLKO_FE;429 else430 buf &= ~PCF8563_REG_CLKO_FE;431 432 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);433 return ret;434}435 436static int pcf8563_clkout_prepare(struct clk_hw *hw)437{438 return pcf8563_clkout_control(hw, 1);439}440 441static void pcf8563_clkout_unprepare(struct clk_hw *hw)442{443 pcf8563_clkout_control(hw, 0);444}445 446static int pcf8563_clkout_is_prepared(struct clk_hw *hw)447{448 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);449 struct i2c_client *client = pcf8563->client;450 unsigned char buf;451 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);452 453 if (ret < 0)454 return ret;455 456 return !!(buf & PCF8563_REG_CLKO_FE);457}458 459static const struct clk_ops pcf8563_clkout_ops = {460 .prepare = pcf8563_clkout_prepare,461 .unprepare = pcf8563_clkout_unprepare,462 .is_prepared = pcf8563_clkout_is_prepared,463 .recalc_rate = pcf8563_clkout_recalc_rate,464 .round_rate = pcf8563_clkout_round_rate,465 .set_rate = pcf8563_clkout_set_rate,466};467 468static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563)469{470 struct i2c_client *client = pcf8563->client;471 struct device_node *node = client->dev.of_node;472 struct clk *clk;473 struct clk_init_data init;474 int ret;475 unsigned char buf;476 477 /* disable the clkout output */478 buf = 0;479 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);480 if (ret < 0)481 return ERR_PTR(ret);482 483 init.name = "pcf8563-clkout";484 init.ops = &pcf8563_clkout_ops;485 init.flags = 0;486 init.parent_names = NULL;487 init.num_parents = 0;488 pcf8563->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(&client->dev, &pcf8563->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#endif502 503static const struct rtc_class_ops pcf8563_rtc_ops = {504 .ioctl = pcf8563_rtc_ioctl,505 .read_time = pcf8563_rtc_read_time,506 .set_time = pcf8563_rtc_set_time,507 .read_alarm = pcf8563_rtc_read_alarm,508 .set_alarm = pcf8563_rtc_set_alarm,509 .alarm_irq_enable = pcf8563_irq_enable,510};511 512static int pcf8563_probe(struct i2c_client *client)513{514 struct pcf8563 *pcf8563;515 int err;516 unsigned char buf;517 518 dev_dbg(&client->dev, "%s\n", __func__);519 520 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))521 return -ENODEV;522 523 pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),524 GFP_KERNEL);525 if (!pcf8563)526 return -ENOMEM;527 528 i2c_set_clientdata(client, pcf8563);529 pcf8563->client = client;530 531 /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */532 buf = PCF8563_TMRC_1_60;533 err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf);534 if (err < 0) {535 dev_err(&client->dev, "%s: write error\n", __func__);536 return err;537 }538 539 /* Clear flags and disable interrupts */540 buf = 0;541 err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);542 if (err < 0) {543 dev_err(&client->dev, "%s: write error\n", __func__);544 return err;545 }546 547 pcf8563->rtc = devm_rtc_allocate_device(&client->dev);548 if (IS_ERR(pcf8563->rtc))549 return PTR_ERR(pcf8563->rtc);550 551 pcf8563->rtc->ops = &pcf8563_rtc_ops;552 /* the pcf8563 alarm only supports a minute accuracy */553 set_bit(RTC_FEATURE_ALARM_RES_MINUTE, pcf8563->rtc->features);554 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, pcf8563->rtc->features);555 clear_bit(RTC_FEATURE_ALARM, pcf8563->rtc->features);556 pcf8563->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;557 pcf8563->rtc->range_max = RTC_TIMESTAMP_END_2099;558 pcf8563->rtc->set_start_time = true;559 560 if (client->irq > 0) {561 unsigned long irqflags = IRQF_TRIGGER_LOW;562 563 if (dev_fwnode(&client->dev))564 irqflags = 0;565 566 err = devm_request_threaded_irq(&client->dev, client->irq,567 NULL, pcf8563_irq,568 IRQF_SHARED | IRQF_ONESHOT | irqflags,569 pcf8563_driver.driver.name, client);570 if (err) {571 dev_err(&client->dev, "unable to request IRQ %d\n",572 client->irq);573 return err;574 }575 } else {576 client->irq = 0;577 }578 579 if (client->irq > 0 || device_property_read_bool(&client->dev, "wakeup-source")) {580 device_init_wakeup(&client->dev, true);581 set_bit(RTC_FEATURE_ALARM, pcf8563->rtc->features);582 }583 584 err = devm_rtc_register_device(pcf8563->rtc);585 if (err)586 return err;587 588#ifdef CONFIG_COMMON_CLK589 /* register clk in common clk framework */590 pcf8563_clkout_register_clk(pcf8563);591#endif592 593 return 0;594}595 596static const struct i2c_device_id pcf8563_id[] = {597 { "pcf8563" },598 { "rtc8564" },599 { "pca8565" },600 { }601};602MODULE_DEVICE_TABLE(i2c, pcf8563_id);603 604#ifdef CONFIG_OF605static const struct of_device_id pcf8563_of_match[] = {606 { .compatible = "nxp,pcf8563" },607 { .compatible = "epson,rtc8564" },608 { .compatible = "microcrystal,rv8564" },609 { .compatible = "nxp,pca8565" },610 {}611};612MODULE_DEVICE_TABLE(of, pcf8563_of_match);613#endif614 615static struct i2c_driver pcf8563_driver = {616 .driver = {617 .name = "rtc-pcf8563",618 .of_match_table = of_match_ptr(pcf8563_of_match),619 },620 .probe = pcf8563_probe,621 .id_table = pcf8563_id,622};623 624module_i2c_driver(pcf8563_driver);625 626MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");627MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");628MODULE_LICENSE("GPL");629