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/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 0x01 25 #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 0x03 31 #define PCF8563_REG_HR 0x04 32 #define PCF8563_REG_DM 0x05 33 #define PCF8563_REG_DW 0x06 34 #define PCF8563_REG_MO 0x07 35 #define PCF8563_REG_YR 0x08 36 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 0x00 43 #define PCF8563_REG_CLKO_F_1024HZ 0x01 44 #define PCF8563_REG_CLKO_F_32HZ 0x02 45 #define PCF8563_REG_CLKO_F_1HZ 0x03 46 47 #define PCF8563_REG_TMRC 0x0E /* timer control */ 48 #define PCF8563_TMRC_ENABLE BIT(7) 49 #define PCF8563_TMRC_4096 0 50 #define PCF8563_TMRC_64 1 51 #define PCF8563_TMRC_1 2 52 #define PCF8563_TMRC_1_60 3 53 #define PCF8563_TMRC_MASK 3 54 55 #define PCF8563_REG_TMR 0x0F /* timer */ 56 57 #define PCF8563_SC_LV 0x80 /* low voltage */ 58 #define PCF8563_MO_C 0x80 /* century */ 59 60 static struct i2c_driver pcf8563_driver; 61 62 struct 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 years 67 * register overflows from 99 to 00 68 * 0 indicates the century is 20xx 69 * 1 indicates the century is 19xx 70 * From RTC8564 datasheet: this bit indicates change of 71 * century. When the year digit data overflows from 99 to 00, 72 * this bit is set. By presetting it to 0 while still in the 73 * 20th century, it will be set in year 2000, ... 74 * There seems no reliable way to know how the system use this 75 * bit. So let's do it heuristically, assuming we are live in 76 * 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_CLK 82 struct clk_hw clkout_hw; 83 #endif 84 }; 85 86 static 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 = buf 100 }, 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 } 110 111 static 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 } 131 132 static 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 else 144 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 } 156 157 static 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 } 174 175 static 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 use 196 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. 197 */ 198 static 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 } 243 244 static 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 } 276 277 static 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 } 294 295 static 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 } 326 327 static 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 } 344 345 static 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_CLK 352 /* 353 * Handling of the clkout 354 */ 355 356 #define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw) 357 358 static const int clkout_rates[] = { 359 32768, 360 1024, 361 32, 362 1, 363 }; 364 365 static 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 } 379 380 static 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 } 391 392 static 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 } 416 417 static 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 else 430 buf &= ~PCF8563_REG_CLKO_FE; 431 432 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf); 433 return ret; 434 } 435 436 static int pcf8563_clkout_prepare(struct clk_hw *hw) 437 { 438 return pcf8563_clkout_control(hw, 1); 439 } 440 441 static void pcf8563_clkout_unprepare(struct clk_hw *hw) 442 { 443 pcf8563_clkout_control(hw, 0); 444 } 445 446 static 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 } 458 459 static 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 }; 467 468 static 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 #endif 502 503 static 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 }; 511 512 static 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 device_set_wakeup_capable(&client->dev, 1); 531 532 /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */ 533 buf = PCF8563_TMRC_1_60; 534 err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf); 535 if (err < 0) { 536 dev_err(&client->dev, "%s: write error\n", __func__); 537 return err; 538 } 539 540 /* Clear flags and disable interrupts */ 541 buf = 0; 542 err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf); 543 if (err < 0) { 544 dev_err(&client->dev, "%s: write error\n", __func__); 545 return err; 546 } 547 548 pcf8563->rtc = devm_rtc_allocate_device(&client->dev); 549 if (IS_ERR(pcf8563->rtc)) 550 return PTR_ERR(pcf8563->rtc); 551 552 pcf8563->rtc->ops = &pcf8563_rtc_ops; 553 /* the pcf8563 alarm only supports a minute accuracy */ 554 set_bit(RTC_FEATURE_ALARM_RES_MINUTE, pcf8563->rtc->features); 555 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, 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 clear_bit(RTC_FEATURE_ALARM, pcf8563->rtc->features); 577 } 578 579 err = devm_rtc_register_device(pcf8563->rtc); 580 if (err) 581 return err; 582 583 #ifdef CONFIG_COMMON_CLK 584 /* register clk in common clk framework */ 585 pcf8563_clkout_register_clk(pcf8563); 586 #endif 587 588 return 0; 589 } 590 591 static const struct i2c_device_id pcf8563_id[] = { 592 { "pcf8563", 0 }, 593 { "rtc8564", 0 }, 594 { "pca8565", 0 }, 595 { } 596 }; 597 MODULE_DEVICE_TABLE(i2c, pcf8563_id); 598 599 #ifdef CONFIG_OF 600 static const struct of_device_id pcf8563_of_match[] = { 601 { .compatible = "nxp,pcf8563" }, 602 { .compatible = "epson,rtc8564" }, 603 { .compatible = "microcrystal,rv8564" }, 604 { .compatible = "nxp,pca8565" }, 605 {} 606 }; 607 MODULE_DEVICE_TABLE(of, pcf8563_of_match); 608 #endif 609 610 static struct i2c_driver pcf8563_driver = { 611 .driver = { 612 .name = "rtc-pcf8563", 613 .of_match_table = of_match_ptr(pcf8563_of_match), 614 }, 615 .probe = pcf8563_probe, 616 .id_table = pcf8563_id, 617 }; 618 619 module_i2c_driver(pcf8563_driver); 620 621 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); 622 MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver"); 623 MODULE_LICENSE("GPL"); 624