1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * An I2C driver for the Philips PCF8563 RTC 4 * Copyright 2005-06 Tower Technologies 5 * 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.pdf 12 */ 13 14 #include <linux/bcd.h> 15 #include <linux/clk-provider.h> 16 #include <linux/err.h> 17 #include <linux/i2c.h> 18 #include <linux/module.h> 19 #include <linux/of.h> 20 #include <linux/regmap.h> 21 #include <linux/rtc.h> 22 #include <linux/slab.h> 23 24 #define PCF8563_REG_ST1 0x00 /* status */ 25 #define PCF8563_REG_ST2 0x01 26 #define PCF8563_BIT_AIE BIT(1) 27 #define PCF8563_BIT_AF BIT(3) 28 #define PCF8563_BITS_ST2_N (7 << 5) 29 30 #define PCF8563_REG_SC 0x02 /* datetime */ 31 #define PCF8563_REG_MN 0x03 32 #define PCF8563_REG_HR 0x04 33 #define PCF8563_REG_DM 0x05 34 #define PCF8563_REG_DW 0x06 35 #define PCF8563_REG_MO 0x07 36 #define PCF8563_REG_YR 0x08 37 38 #define PCF8563_REG_AMN 0x09 /* alarm */ 39 40 #define PCF8563_REG_CLKO 0x0D /* clock out */ 41 #define PCF8563_REG_CLKO_FE 0x80 /* clock out enabled */ 42 #define PCF8563_REG_CLKO_F_MASK 0x03 /* frequenc mask */ 43 #define PCF8563_REG_CLKO_F_32768HZ 0x00 44 #define PCF8563_REG_CLKO_F_1024HZ 0x01 45 #define PCF8563_REG_CLKO_F_32HZ 0x02 46 #define PCF8563_REG_CLKO_F_1HZ 0x03 47 48 #define PCF8563_REG_TMRC 0x0E /* timer control */ 49 #define PCF8563_TMRC_ENABLE BIT(7) 50 #define PCF8563_TMRC_4096 0 51 #define PCF8563_TMRC_64 1 52 #define PCF8563_TMRC_1 2 53 #define PCF8563_TMRC_1_60 3 54 #define PCF8563_TMRC_MASK 3 55 56 #define PCF8563_REG_TMR 0x0F /* timer */ 57 58 #define PCF8563_SC_LV 0x80 /* low voltage */ 59 #define PCF8563_MO_C 0x80 /* century */ 60 61 static struct i2c_driver pcf8563_driver; 62 63 struct pcf8563 { 64 struct rtc_device *rtc; 65 /* 66 * The meaning of MO_C bit varies by the chip type. 67 * From PCF8563 datasheet: this bit is toggled when the years 68 * register overflows from 99 to 00 69 * 0 indicates the century is 20xx 70 * 1 indicates the century is 19xx 71 * From RTC8564 datasheet: this bit indicates change of 72 * century. When the year digit data overflows from 99 to 00, 73 * this bit is set. By presetting it to 0 while still in the 74 * 20th century, it will be set in year 2000, ... 75 * There seems no reliable way to know how the system use this 76 * bit. So let's do it heuristically, assuming we are live in 77 * 1970...2069. 78 */ 79 int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */ 80 81 struct regmap *regmap; 82 #ifdef CONFIG_COMMON_CLK 83 struct clk_hw clkout_hw; 84 #endif 85 }; 86 87 static int pcf8563_set_alarm_mode(struct pcf8563 *pcf8563, bool on) 88 { 89 u32 buf; 90 int err; 91 92 err = regmap_read(pcf8563->regmap, PCF8563_REG_ST2, &buf); 93 if (err < 0) 94 return err; 95 96 if (on) 97 buf |= PCF8563_BIT_AIE; 98 else 99 buf &= ~PCF8563_BIT_AIE; 100 101 buf &= ~(PCF8563_BIT_AF | PCF8563_BITS_ST2_N); 102 103 return regmap_write(pcf8563->regmap, PCF8563_REG_ST2, buf); 104 } 105 106 static int pcf8563_get_alarm_mode(struct pcf8563 *pcf8563, unsigned char *en, 107 unsigned char *pen) 108 { 109 u32 buf; 110 int err; 111 112 err = regmap_read(pcf8563->regmap, PCF8563_REG_ST2, &buf); 113 if (err < 0) 114 return err; 115 116 if (en) 117 *en = !!(buf & PCF8563_BIT_AIE); 118 if (pen) 119 *pen = !!(buf & PCF8563_BIT_AF); 120 121 return 0; 122 } 123 124 static irqreturn_t pcf8563_irq(int irq, void *dev_id) 125 { 126 struct pcf8563 *pcf8563 = dev_id; 127 char pending; 128 int err; 129 130 err = pcf8563_get_alarm_mode(pcf8563, NULL, &pending); 131 if (err) 132 return IRQ_NONE; 133 134 if (pending) { 135 rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF); 136 pcf8563_set_alarm_mode(pcf8563, 1); 137 return IRQ_HANDLED; 138 } 139 140 return IRQ_NONE; 141 } 142 143 /* 144 * In the routines that deal directly with the pcf8563 hardware, we use 145 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. 146 */ 147 static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm) 148 { 149 struct pcf8563 *pcf8563 = dev_get_drvdata(dev); 150 unsigned char buf[9]; 151 int err; 152 153 err = regmap_bulk_read(pcf8563->regmap, PCF8563_REG_ST1, buf, 154 sizeof(buf)); 155 if (err < 0) 156 return err; 157 158 if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) { 159 dev_err(dev, 160 "low voltage detected, date/time is not reliable.\n"); 161 return -EINVAL; 162 } 163 164 dev_dbg(dev, 165 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, " 166 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n", 167 __func__, 168 buf[0], buf[1], buf[2], buf[3], 169 buf[4], buf[5], buf[6], buf[7], 170 buf[8]); 171 172 tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F); 173 tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F); 174 tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */ 175 tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F); 176 tm->tm_wday = buf[PCF8563_REG_DW] & 0x07; 177 tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */ 178 tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]) + 100; 179 /* detect the polarity heuristically. see note above. */ 180 pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ? 181 (tm->tm_year >= 100) : (tm->tm_year < 100); 182 183 dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, " 184 "mday=%d, mon=%d, year=%d, wday=%d\n", 185 __func__, 186 tm->tm_sec, tm->tm_min, tm->tm_hour, 187 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); 188 189 return 0; 190 } 191 192 static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm) 193 { 194 struct pcf8563 *pcf8563 = dev_get_drvdata(dev); 195 unsigned char buf[9]; 196 197 dev_dbg(dev, "%s: secs=%d, mins=%d, hours=%d, " 198 "mday=%d, mon=%d, year=%d, wday=%d\n", 199 __func__, 200 tm->tm_sec, tm->tm_min, tm->tm_hour, 201 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); 202 203 /* hours, minutes and seconds */ 204 buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec); 205 buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min); 206 buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour); 207 208 buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday); 209 210 /* month, 1 - 12 */ 211 buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1); 212 213 /* year and century */ 214 buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year - 100); 215 if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100)) 216 buf[PCF8563_REG_MO] |= PCF8563_MO_C; 217 218 buf[PCF8563_REG_DW] = tm->tm_wday & 0x07; 219 220 return regmap_bulk_write(pcf8563->regmap, PCF8563_REG_SC, 221 buf + PCF8563_REG_SC, 222 sizeof(buf) - PCF8563_REG_SC); 223 } 224 225 static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 226 { 227 struct pcf8563 *pcf8563 = dev_get_drvdata(dev); 228 int ret; 229 230 switch (cmd) { 231 case RTC_VL_READ: 232 ret = regmap_test_bits(pcf8563->regmap, PCF8563_REG_SC, 233 PCF8563_SC_LV); 234 if (ret < 0) 235 return ret; 236 237 return put_user(ret ? RTC_VL_DATA_INVALID : 0, 238 (unsigned int __user *)arg); 239 default: 240 return -ENOIOCTLCMD; 241 } 242 } 243 244 static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm) 245 { 246 struct pcf8563 *pcf8563 = dev_get_drvdata(dev); 247 unsigned char buf[4]; 248 int err; 249 250 err = regmap_bulk_read(pcf8563->regmap, PCF8563_REG_AMN, buf, 251 sizeof(buf)); 252 if (err < 0) 253 return err; 254 255 dev_dbg(dev, 256 "%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n", 257 __func__, buf[0], buf[1], buf[2], buf[3]); 258 259 tm->time.tm_sec = 0; 260 tm->time.tm_min = bcd2bin(buf[0] & 0x7F); 261 tm->time.tm_hour = bcd2bin(buf[1] & 0x3F); 262 tm->time.tm_mday = bcd2bin(buf[2] & 0x3F); 263 tm->time.tm_wday = bcd2bin(buf[3] & 0x7); 264 265 err = pcf8563_get_alarm_mode(pcf8563, &tm->enabled, &tm->pending); 266 if (err < 0) 267 return err; 268 269 dev_dbg(dev, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d," 270 " enabled=%d, pending=%d\n", __func__, tm->time.tm_min, 271 tm->time.tm_hour, tm->time.tm_mday, tm->time.tm_wday, 272 tm->enabled, tm->pending); 273 274 return 0; 275 } 276 277 static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm) 278 { 279 struct pcf8563 *pcf8563 = dev_get_drvdata(dev); 280 unsigned char buf[4]; 281 int err; 282 283 buf[0] = bin2bcd(tm->time.tm_min); 284 buf[1] = bin2bcd(tm->time.tm_hour); 285 buf[2] = bin2bcd(tm->time.tm_mday); 286 buf[3] = tm->time.tm_wday & 0x07; 287 288 err = regmap_bulk_write(pcf8563->regmap, PCF8563_REG_AMN, buf, 289 sizeof(buf)); 290 if (err) 291 return err; 292 293 return pcf8563_set_alarm_mode(pcf8563, !!tm->enabled); 294 } 295 296 static int pcf8563_irq_enable(struct device *dev, unsigned int enabled) 297 { 298 struct pcf8563 *pcf8563 = dev_get_drvdata(dev); 299 300 dev_dbg(dev, "%s: en=%d\n", __func__, enabled); 301 return pcf8563_set_alarm_mode(pcf8563, !!enabled); 302 } 303 304 #ifdef CONFIG_COMMON_CLK 305 /* 306 * Handling of the clkout 307 */ 308 309 #define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw) 310 311 static const int clkout_rates[] = { 312 32768, 313 1024, 314 32, 315 1, 316 }; 317 318 static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw, 319 unsigned long parent_rate) 320 { 321 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw); 322 u32 buf; 323 int ret; 324 325 ret = regmap_read(pcf8563->regmap, PCF8563_REG_CLKO, &buf); 326 if (ret < 0) 327 return 0; 328 329 buf &= PCF8563_REG_CLKO_F_MASK; 330 return clkout_rates[buf]; 331 } 332 333 static int pcf8563_clkout_determine_rate(struct clk_hw *hw, 334 struct clk_rate_request *req) 335 { 336 int i; 337 338 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++) 339 if (clkout_rates[i] <= req->rate) { 340 req->rate = clkout_rates[i]; 341 342 return 0; 343 } 344 345 req->rate = clkout_rates[0]; 346 347 return 0; 348 } 349 350 static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate, 351 unsigned long parent_rate) 352 { 353 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw); 354 int i, ret; 355 u32 buf; 356 357 ret = regmap_read(pcf8563->regmap, PCF8563_REG_CLKO, &buf); 358 if (ret < 0) 359 return ret; 360 361 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++) 362 if (clkout_rates[i] == rate) { 363 buf &= ~PCF8563_REG_CLKO_F_MASK; 364 buf |= i; 365 return regmap_update_bits(pcf8563->regmap, 366 PCF8563_REG_CLKO, 367 PCF8563_REG_CLKO_F_MASK, 368 buf); 369 } 370 371 return -EINVAL; 372 } 373 374 static int pcf8563_clkout_control(struct clk_hw *hw, bool enable) 375 { 376 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw); 377 u32 buf; 378 int ret; 379 380 ret = regmap_read(pcf8563->regmap, PCF8563_REG_CLKO, &buf); 381 if (ret < 0) 382 return ret; 383 384 if (enable) 385 buf |= PCF8563_REG_CLKO_FE; 386 else 387 buf &= ~PCF8563_REG_CLKO_FE; 388 389 return regmap_update_bits(pcf8563->regmap, PCF8563_REG_CLKO, 390 PCF8563_REG_CLKO_FE, buf); 391 } 392 393 static int pcf8563_clkout_prepare(struct clk_hw *hw) 394 { 395 return pcf8563_clkout_control(hw, 1); 396 } 397 398 static void pcf8563_clkout_unprepare(struct clk_hw *hw) 399 { 400 pcf8563_clkout_control(hw, 0); 401 } 402 403 static int pcf8563_clkout_is_prepared(struct clk_hw *hw) 404 { 405 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw); 406 u32 buf; 407 int ret; 408 409 ret = regmap_read(pcf8563->regmap, PCF8563_REG_CLKO, &buf); 410 if (ret < 0) 411 return ret; 412 413 return !!(buf & PCF8563_REG_CLKO_FE); 414 } 415 416 static const struct clk_ops pcf8563_clkout_ops = { 417 .prepare = pcf8563_clkout_prepare, 418 .unprepare = pcf8563_clkout_unprepare, 419 .is_prepared = pcf8563_clkout_is_prepared, 420 .recalc_rate = pcf8563_clkout_recalc_rate, 421 .determine_rate = pcf8563_clkout_determine_rate, 422 .set_rate = pcf8563_clkout_set_rate, 423 }; 424 425 static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563) 426 { 427 struct device_node *node = pcf8563->rtc->dev.of_node; 428 struct clk_init_data init; 429 struct clk *clk; 430 int ret; 431 432 /* disable the clkout output */ 433 ret = regmap_clear_bits(pcf8563->regmap, PCF8563_REG_CLKO, 434 PCF8563_REG_CLKO_FE); 435 if (ret < 0) 436 return ERR_PTR(ret); 437 438 init.name = "pcf8563-clkout"; 439 init.ops = &pcf8563_clkout_ops; 440 init.flags = 0; 441 init.parent_names = NULL; 442 init.num_parents = 0; 443 pcf8563->clkout_hw.init = &init; 444 445 /* optional override of the clockname */ 446 of_property_read_string(node, "clock-output-names", &init.name); 447 448 /* register the clock */ 449 clk = devm_clk_register(&pcf8563->rtc->dev, &pcf8563->clkout_hw); 450 451 if (!IS_ERR(clk)) 452 of_clk_add_provider(node, of_clk_src_simple_get, clk); 453 454 return clk; 455 } 456 #endif 457 458 static const struct rtc_class_ops pcf8563_rtc_ops = { 459 .ioctl = pcf8563_rtc_ioctl, 460 .read_time = pcf8563_rtc_read_time, 461 .set_time = pcf8563_rtc_set_time, 462 .read_alarm = pcf8563_rtc_read_alarm, 463 .set_alarm = pcf8563_rtc_set_alarm, 464 .alarm_irq_enable = pcf8563_irq_enable, 465 }; 466 467 static const struct regmap_config regmap_config = { 468 .reg_bits = 8, 469 .val_bits = 8, 470 .max_register = 0xF, 471 }; 472 473 static int pcf8563_probe(struct i2c_client *client) 474 { 475 struct pcf8563 *pcf8563; 476 int err; 477 478 dev_dbg(&client->dev, "%s\n", __func__); 479 480 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) 481 return -ENODEV; 482 483 pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563), 484 GFP_KERNEL); 485 if (!pcf8563) 486 return -ENOMEM; 487 488 pcf8563->regmap = devm_regmap_init_i2c(client, ®map_config); 489 if (IS_ERR(pcf8563->regmap)) 490 return PTR_ERR(pcf8563->regmap); 491 492 i2c_set_clientdata(client, pcf8563); 493 device_set_wakeup_capable(&client->dev, 1); 494 495 /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */ 496 err = regmap_set_bits(pcf8563->regmap, PCF8563_REG_TMRC, 497 PCF8563_TMRC_1_60); 498 if (err < 0) { 499 dev_err(&client->dev, "%s: write error\n", __func__); 500 return err; 501 } 502 503 /* Clear flags and disable interrupts */ 504 err = regmap_write(pcf8563->regmap, PCF8563_REG_ST2, 0); 505 if (err < 0) { 506 dev_err(&client->dev, "%s: write error\n", __func__); 507 return err; 508 } 509 510 pcf8563->rtc = devm_rtc_allocate_device(&client->dev); 511 if (IS_ERR(pcf8563->rtc)) 512 return PTR_ERR(pcf8563->rtc); 513 514 pcf8563->rtc->ops = &pcf8563_rtc_ops; 515 /* the pcf8563 alarm only supports a minute accuracy */ 516 set_bit(RTC_FEATURE_ALARM_RES_MINUTE, pcf8563->rtc->features); 517 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, pcf8563->rtc->features); 518 clear_bit(RTC_FEATURE_ALARM, pcf8563->rtc->features); 519 pcf8563->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; 520 pcf8563->rtc->range_max = RTC_TIMESTAMP_END_2099; 521 pcf8563->rtc->set_start_time = true; 522 523 if (client->irq > 0) { 524 unsigned long irqflags = IRQF_TRIGGER_LOW; 525 526 if (dev_fwnode(&client->dev)) 527 irqflags = 0; 528 529 err = devm_request_threaded_irq(&client->dev, client->irq, 530 NULL, pcf8563_irq, 531 IRQF_SHARED | IRQF_ONESHOT | irqflags, 532 pcf8563_driver.driver.name, client); 533 if (err) { 534 dev_err(&client->dev, "unable to request IRQ %d\n", 535 client->irq); 536 return err; 537 } 538 } else { 539 client->irq = 0; 540 } 541 542 if (client->irq > 0 || device_property_read_bool(&client->dev, "wakeup-source")) { 543 device_init_wakeup(&client->dev, true); 544 set_bit(RTC_FEATURE_ALARM, pcf8563->rtc->features); 545 } 546 547 err = devm_rtc_register_device(pcf8563->rtc); 548 if (err) 549 return err; 550 551 #ifdef CONFIG_COMMON_CLK 552 /* register clk in common clk framework */ 553 pcf8563_clkout_register_clk(pcf8563); 554 #endif 555 556 return 0; 557 } 558 559 static const struct i2c_device_id pcf8563_id[] = { 560 { "pcf8563" }, 561 { "rtc8564" }, 562 { "pca8565" }, 563 { } 564 }; 565 MODULE_DEVICE_TABLE(i2c, pcf8563_id); 566 567 #ifdef CONFIG_OF 568 static const struct of_device_id pcf8563_of_match[] = { 569 { .compatible = "nxp,pcf8563" }, 570 { .compatible = "epson,rtc8564" }, 571 { .compatible = "microcrystal,rv8564" }, 572 { .compatible = "nxp,pca8565" }, 573 {} 574 }; 575 MODULE_DEVICE_TABLE(of, pcf8563_of_match); 576 #endif 577 578 static struct i2c_driver pcf8563_driver = { 579 .driver = { 580 .name = "rtc-pcf8563", 581 .of_match_table = of_match_ptr(pcf8563_of_match), 582 }, 583 .probe = pcf8563_probe, 584 .id_table = pcf8563_id, 585 }; 586 587 module_i2c_driver(pcf8563_driver); 588 589 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); 590 MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver"); 591 MODULE_LICENSE("GPL"); 592