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 /* The alarm has no seconds, round up to nearest minute */ 334 if (tm->time.tm_sec) { 335 time64_t alarm_time = rtc_tm_to_time64(&tm->time); 336 337 alarm_time += 60 - tm->time.tm_sec; 338 rtc_time64_to_tm(alarm_time, &tm->time); 339 } 340 341 dev_dbg(dev, "%s, min=%d hour=%d wday=%d mday=%d " 342 "enabled=%d pending=%d\n", __func__, 343 tm->time.tm_min, tm->time.tm_hour, tm->time.tm_wday, 344 tm->time.tm_mday, tm->enabled, tm->pending); 345 346 buf[0] = bin2bcd(tm->time.tm_min); 347 buf[1] = bin2bcd(tm->time.tm_hour); 348 buf[2] = bin2bcd(tm->time.tm_mday); 349 buf[3] = tm->time.tm_wday & 0x07; 350 351 err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf); 352 if (err) 353 return err; 354 355 return pcf8563_set_alarm_mode(client, !!tm->enabled); 356 } 357 358 static int pcf8563_irq_enable(struct device *dev, unsigned int enabled) 359 { 360 dev_dbg(dev, "%s: en=%d\n", __func__, enabled); 361 return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled); 362 } 363 364 #ifdef CONFIG_COMMON_CLK 365 /* 366 * Handling of the clkout 367 */ 368 369 #define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw) 370 371 static const int clkout_rates[] = { 372 32768, 373 1024, 374 32, 375 1, 376 }; 377 378 static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw, 379 unsigned long parent_rate) 380 { 381 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw); 382 struct i2c_client *client = pcf8563->client; 383 unsigned char buf; 384 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf); 385 386 if (ret < 0) 387 return 0; 388 389 buf &= PCF8563_REG_CLKO_F_MASK; 390 return clkout_rates[buf]; 391 } 392 393 static long pcf8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate, 394 unsigned long *prate) 395 { 396 int i; 397 398 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++) 399 if (clkout_rates[i] <= rate) 400 return clkout_rates[i]; 401 402 return 0; 403 } 404 405 static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate, 406 unsigned long parent_rate) 407 { 408 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw); 409 struct i2c_client *client = pcf8563->client; 410 unsigned char buf; 411 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf); 412 int i; 413 414 if (ret < 0) 415 return ret; 416 417 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++) 418 if (clkout_rates[i] == rate) { 419 buf &= ~PCF8563_REG_CLKO_F_MASK; 420 buf |= i; 421 ret = pcf8563_write_block_data(client, 422 PCF8563_REG_CLKO, 1, 423 &buf); 424 return ret; 425 } 426 427 return -EINVAL; 428 } 429 430 static int pcf8563_clkout_control(struct clk_hw *hw, bool enable) 431 { 432 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw); 433 struct i2c_client *client = pcf8563->client; 434 unsigned char buf; 435 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf); 436 437 if (ret < 0) 438 return ret; 439 440 if (enable) 441 buf |= PCF8563_REG_CLKO_FE; 442 else 443 buf &= ~PCF8563_REG_CLKO_FE; 444 445 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf); 446 return ret; 447 } 448 449 static int pcf8563_clkout_prepare(struct clk_hw *hw) 450 { 451 return pcf8563_clkout_control(hw, 1); 452 } 453 454 static void pcf8563_clkout_unprepare(struct clk_hw *hw) 455 { 456 pcf8563_clkout_control(hw, 0); 457 } 458 459 static int pcf8563_clkout_is_prepared(struct clk_hw *hw) 460 { 461 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw); 462 struct i2c_client *client = pcf8563->client; 463 unsigned char buf; 464 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf); 465 466 if (ret < 0) 467 return ret; 468 469 return !!(buf & PCF8563_REG_CLKO_FE); 470 } 471 472 static const struct clk_ops pcf8563_clkout_ops = { 473 .prepare = pcf8563_clkout_prepare, 474 .unprepare = pcf8563_clkout_unprepare, 475 .is_prepared = pcf8563_clkout_is_prepared, 476 .recalc_rate = pcf8563_clkout_recalc_rate, 477 .round_rate = pcf8563_clkout_round_rate, 478 .set_rate = pcf8563_clkout_set_rate, 479 }; 480 481 static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563) 482 { 483 struct i2c_client *client = pcf8563->client; 484 struct device_node *node = client->dev.of_node; 485 struct clk *clk; 486 struct clk_init_data init; 487 int ret; 488 unsigned char buf; 489 490 /* disable the clkout output */ 491 buf = 0; 492 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf); 493 if (ret < 0) 494 return ERR_PTR(ret); 495 496 init.name = "pcf8563-clkout"; 497 init.ops = &pcf8563_clkout_ops; 498 init.flags = 0; 499 init.parent_names = NULL; 500 init.num_parents = 0; 501 pcf8563->clkout_hw.init = &init; 502 503 /* optional override of the clockname */ 504 of_property_read_string(node, "clock-output-names", &init.name); 505 506 /* register the clock */ 507 clk = devm_clk_register(&client->dev, &pcf8563->clkout_hw); 508 509 if (!IS_ERR(clk)) 510 of_clk_add_provider(node, of_clk_src_simple_get, clk); 511 512 return clk; 513 } 514 #endif 515 516 static const struct rtc_class_ops pcf8563_rtc_ops = { 517 .ioctl = pcf8563_rtc_ioctl, 518 .read_time = pcf8563_rtc_read_time, 519 .set_time = pcf8563_rtc_set_time, 520 .read_alarm = pcf8563_rtc_read_alarm, 521 .set_alarm = pcf8563_rtc_set_alarm, 522 .alarm_irq_enable = pcf8563_irq_enable, 523 }; 524 525 static int pcf8563_probe(struct i2c_client *client, 526 const struct i2c_device_id *id) 527 { 528 struct pcf8563 *pcf8563; 529 int err; 530 unsigned char buf; 531 532 dev_dbg(&client->dev, "%s\n", __func__); 533 534 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) 535 return -ENODEV; 536 537 pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563), 538 GFP_KERNEL); 539 if (!pcf8563) 540 return -ENOMEM; 541 542 i2c_set_clientdata(client, pcf8563); 543 pcf8563->client = client; 544 device_set_wakeup_capable(&client->dev, 1); 545 546 /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */ 547 buf = PCF8563_TMRC_1_60; 548 err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf); 549 if (err < 0) { 550 dev_err(&client->dev, "%s: write error\n", __func__); 551 return err; 552 } 553 554 /* Clear flags and disable interrupts */ 555 buf = 0; 556 err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf); 557 if (err < 0) { 558 dev_err(&client->dev, "%s: write error\n", __func__); 559 return err; 560 } 561 562 pcf8563->rtc = devm_rtc_allocate_device(&client->dev); 563 if (IS_ERR(pcf8563->rtc)) 564 return PTR_ERR(pcf8563->rtc); 565 566 pcf8563->rtc->ops = &pcf8563_rtc_ops; 567 /* the pcf8563 alarm only supports a minute accuracy */ 568 pcf8563->rtc->uie_unsupported = 1; 569 pcf8563->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; 570 pcf8563->rtc->range_max = RTC_TIMESTAMP_END_2099; 571 pcf8563->rtc->set_start_time = true; 572 573 if (client->irq > 0) { 574 err = devm_request_threaded_irq(&client->dev, client->irq, 575 NULL, pcf8563_irq, 576 IRQF_SHARED | IRQF_ONESHOT | IRQF_TRIGGER_LOW, 577 pcf8563_driver.driver.name, client); 578 if (err) { 579 dev_err(&client->dev, "unable to request IRQ %d\n", 580 client->irq); 581 return err; 582 } 583 } 584 585 err = devm_rtc_register_device(pcf8563->rtc); 586 if (err) 587 return err; 588 589 #ifdef CONFIG_COMMON_CLK 590 /* register clk in common clk framework */ 591 pcf8563_clkout_register_clk(pcf8563); 592 #endif 593 594 return 0; 595 } 596 597 static const struct i2c_device_id pcf8563_id[] = { 598 { "pcf8563", 0 }, 599 { "rtc8564", 0 }, 600 { "pca8565", 0 }, 601 { } 602 }; 603 MODULE_DEVICE_TABLE(i2c, pcf8563_id); 604 605 #ifdef CONFIG_OF 606 static const struct of_device_id pcf8563_of_match[] = { 607 { .compatible = "nxp,pcf8563" }, 608 { .compatible = "epson,rtc8564" }, 609 { .compatible = "microcrystal,rv8564" }, 610 { .compatible = "nxp,pca8565" }, 611 {} 612 }; 613 MODULE_DEVICE_TABLE(of, pcf8563_of_match); 614 #endif 615 616 static struct i2c_driver pcf8563_driver = { 617 .driver = { 618 .name = "rtc-pcf8563", 619 .of_match_table = of_match_ptr(pcf8563_of_match), 620 }, 621 .probe = pcf8563_probe, 622 .id_table = pcf8563_id, 623 }; 624 625 module_i2c_driver(pcf8563_driver); 626 627 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); 628 MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver"); 629 MODULE_LICENSE("GPL"); 630