1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * An I2C driver for the PCF85063 RTC 4 * Copyright 2014 Rose Technology 5 * 6 * Author: Søren Andersen <san@rosetechnology.dk> 7 * Maintainers: http://www.nslu2-linux.org/ 8 * 9 * Copyright (C) 2019 Micro Crystal AG 10 * Author: Alexandre Belloni <alexandre.belloni@bootlin.com> 11 */ 12 #include <linux/clk-provider.h> 13 #include <linux/i2c.h> 14 #include <linux/bcd.h> 15 #include <linux/rtc.h> 16 #include <linux/module.h> 17 #include <linux/of_device.h> 18 #include <linux/pm_wakeirq.h> 19 #include <linux/regmap.h> 20 21 /* 22 * Information for this driver was pulled from the following datasheets. 23 * 24 * https://www.nxp.com/documents/data_sheet/PCF85063A.pdf 25 * https://www.nxp.com/documents/data_sheet/PCF85063TP.pdf 26 * 27 * PCF85063A -- Rev. 6 — 18 November 2015 28 * PCF85063TP -- Rev. 4 — 6 May 2015 29 * 30 * https://www.microcrystal.com/fileadmin/Media/Products/RTC/App.Manual/RV-8263-C7_App-Manual.pdf 31 * RV8263 -- Rev. 1.0 — January 2019 32 */ 33 34 #define PCF85063_REG_CTRL1 0x00 /* status */ 35 #define PCF85063_REG_CTRL1_CAP_SEL BIT(0) 36 #define PCF85063_REG_CTRL1_STOP BIT(5) 37 38 #define PCF85063_REG_CTRL2 0x01 39 #define PCF85063_CTRL2_AF BIT(6) 40 #define PCF85063_CTRL2_AIE BIT(7) 41 42 #define PCF85063_REG_OFFSET 0x02 43 #define PCF85063_OFFSET_SIGN_BIT 6 /* 2's complement sign bit */ 44 #define PCF85063_OFFSET_MODE BIT(7) 45 #define PCF85063_OFFSET_STEP0 4340 46 #define PCF85063_OFFSET_STEP1 4069 47 48 #define PCF85063_REG_CLKO_F_MASK 0x07 /* frequency mask */ 49 #define PCF85063_REG_CLKO_F_32768HZ 0x00 50 #define PCF85063_REG_CLKO_F_OFF 0x07 51 52 #define PCF85063_REG_RAM 0x03 53 54 #define PCF85063_REG_SC 0x04 /* datetime */ 55 #define PCF85063_REG_SC_OS 0x80 56 57 #define PCF85063_REG_ALM_S 0x0b 58 #define PCF85063_AEN BIT(7) 59 60 struct pcf85063_config { 61 struct regmap_config regmap; 62 unsigned has_alarms:1; 63 unsigned force_cap_7000:1; 64 }; 65 66 struct pcf85063 { 67 struct rtc_device *rtc; 68 struct regmap *regmap; 69 #ifdef CONFIG_COMMON_CLK 70 struct clk_hw clkout_hw; 71 #endif 72 }; 73 74 static int pcf85063_rtc_read_time(struct device *dev, struct rtc_time *tm) 75 { 76 struct pcf85063 *pcf85063 = dev_get_drvdata(dev); 77 int rc; 78 u8 regs[7]; 79 80 /* 81 * while reading, the time/date registers are blocked and not updated 82 * anymore until the access is finished. To not lose a second 83 * event, the access must be finished within one second. So, read all 84 * time/date registers in one turn. 85 */ 86 rc = regmap_bulk_read(pcf85063->regmap, PCF85063_REG_SC, regs, 87 sizeof(regs)); 88 if (rc) 89 return rc; 90 91 /* if the clock has lost its power it makes no sense to use its time */ 92 if (regs[0] & PCF85063_REG_SC_OS) { 93 dev_warn(&pcf85063->rtc->dev, "Power loss detected, invalid time\n"); 94 return -EINVAL; 95 } 96 97 tm->tm_sec = bcd2bin(regs[0] & 0x7F); 98 tm->tm_min = bcd2bin(regs[1] & 0x7F); 99 tm->tm_hour = bcd2bin(regs[2] & 0x3F); /* rtc hr 0-23 */ 100 tm->tm_mday = bcd2bin(regs[3] & 0x3F); 101 tm->tm_wday = regs[4] & 0x07; 102 tm->tm_mon = bcd2bin(regs[5] & 0x1F) - 1; /* rtc mn 1-12 */ 103 tm->tm_year = bcd2bin(regs[6]); 104 tm->tm_year += 100; 105 106 return 0; 107 } 108 109 static int pcf85063_rtc_set_time(struct device *dev, struct rtc_time *tm) 110 { 111 struct pcf85063 *pcf85063 = dev_get_drvdata(dev); 112 int rc; 113 u8 regs[7]; 114 115 /* 116 * to accurately set the time, reset the divider chain and keep it in 117 * reset state until all time/date registers are written 118 */ 119 rc = regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL1, 120 PCF85063_REG_CTRL1_STOP, 121 PCF85063_REG_CTRL1_STOP); 122 if (rc) 123 return rc; 124 125 /* hours, minutes and seconds */ 126 regs[0] = bin2bcd(tm->tm_sec) & 0x7F; /* clear OS flag */ 127 128 regs[1] = bin2bcd(tm->tm_min); 129 regs[2] = bin2bcd(tm->tm_hour); 130 131 /* Day of month, 1 - 31 */ 132 regs[3] = bin2bcd(tm->tm_mday); 133 134 /* Day, 0 - 6 */ 135 regs[4] = tm->tm_wday & 0x07; 136 137 /* month, 1 - 12 */ 138 regs[5] = bin2bcd(tm->tm_mon + 1); 139 140 /* year and century */ 141 regs[6] = bin2bcd(tm->tm_year - 100); 142 143 /* write all registers at once */ 144 rc = regmap_bulk_write(pcf85063->regmap, PCF85063_REG_SC, 145 regs, sizeof(regs)); 146 if (rc) 147 return rc; 148 149 /* 150 * Write the control register as a separate action since the size of 151 * the register space is different between the PCF85063TP and 152 * PCF85063A devices. The rollover point can not be used. 153 */ 154 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL1, 155 PCF85063_REG_CTRL1_STOP, 0); 156 } 157 158 static int pcf85063_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 159 { 160 struct pcf85063 *pcf85063 = dev_get_drvdata(dev); 161 u8 buf[4]; 162 unsigned int val; 163 int ret; 164 165 ret = regmap_bulk_read(pcf85063->regmap, PCF85063_REG_ALM_S, 166 buf, sizeof(buf)); 167 if (ret) 168 return ret; 169 170 alrm->time.tm_sec = bcd2bin(buf[0]); 171 alrm->time.tm_min = bcd2bin(buf[1]); 172 alrm->time.tm_hour = bcd2bin(buf[2]); 173 alrm->time.tm_mday = bcd2bin(buf[3]); 174 175 ret = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &val); 176 if (ret) 177 return ret; 178 179 alrm->enabled = !!(val & PCF85063_CTRL2_AIE); 180 181 return 0; 182 } 183 184 static int pcf85063_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 185 { 186 struct pcf85063 *pcf85063 = dev_get_drvdata(dev); 187 u8 buf[5]; 188 int ret; 189 190 buf[0] = bin2bcd(alrm->time.tm_sec); 191 buf[1] = bin2bcd(alrm->time.tm_min); 192 buf[2] = bin2bcd(alrm->time.tm_hour); 193 buf[3] = bin2bcd(alrm->time.tm_mday); 194 buf[4] = PCF85063_AEN; /* Do not match on week day */ 195 196 ret = regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2, 197 PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF, 0); 198 if (ret) 199 return ret; 200 201 ret = regmap_bulk_write(pcf85063->regmap, PCF85063_REG_ALM_S, 202 buf, sizeof(buf)); 203 if (ret) 204 return ret; 205 206 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2, 207 PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF, 208 alrm->enabled ? PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF : PCF85063_CTRL2_AF); 209 } 210 211 static int pcf85063_rtc_alarm_irq_enable(struct device *dev, 212 unsigned int enabled) 213 { 214 struct pcf85063 *pcf85063 = dev_get_drvdata(dev); 215 216 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2, 217 PCF85063_CTRL2_AIE, 218 enabled ? PCF85063_CTRL2_AIE : 0); 219 } 220 221 static irqreturn_t pcf85063_rtc_handle_irq(int irq, void *dev_id) 222 { 223 struct pcf85063 *pcf85063 = dev_id; 224 unsigned int val; 225 int err; 226 227 err = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &val); 228 if (err) 229 return IRQ_NONE; 230 231 if (val & PCF85063_CTRL2_AF) { 232 rtc_update_irq(pcf85063->rtc, 1, RTC_IRQF | RTC_AF); 233 regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2, 234 PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF, 235 0); 236 return IRQ_HANDLED; 237 } 238 239 return IRQ_NONE; 240 } 241 242 static int pcf85063_read_offset(struct device *dev, long *offset) 243 { 244 struct pcf85063 *pcf85063 = dev_get_drvdata(dev); 245 long val; 246 u32 reg; 247 int ret; 248 249 ret = regmap_read(pcf85063->regmap, PCF85063_REG_OFFSET, ®); 250 if (ret < 0) 251 return ret; 252 253 val = sign_extend32(reg & ~PCF85063_OFFSET_MODE, 254 PCF85063_OFFSET_SIGN_BIT); 255 256 if (reg & PCF85063_OFFSET_MODE) 257 *offset = val * PCF85063_OFFSET_STEP1; 258 else 259 *offset = val * PCF85063_OFFSET_STEP0; 260 261 return 0; 262 } 263 264 static int pcf85063_set_offset(struct device *dev, long offset) 265 { 266 struct pcf85063 *pcf85063 = dev_get_drvdata(dev); 267 s8 mode0, mode1, reg; 268 unsigned int error0, error1; 269 270 if (offset > PCF85063_OFFSET_STEP0 * 63) 271 return -ERANGE; 272 if (offset < PCF85063_OFFSET_STEP0 * -64) 273 return -ERANGE; 274 275 mode0 = DIV_ROUND_CLOSEST(offset, PCF85063_OFFSET_STEP0); 276 mode1 = DIV_ROUND_CLOSEST(offset, PCF85063_OFFSET_STEP1); 277 278 error0 = abs(offset - (mode0 * PCF85063_OFFSET_STEP0)); 279 error1 = abs(offset - (mode1 * PCF85063_OFFSET_STEP1)); 280 if (mode1 > 63 || mode1 < -64 || error0 < error1) 281 reg = mode0 & ~PCF85063_OFFSET_MODE; 282 else 283 reg = mode1 | PCF85063_OFFSET_MODE; 284 285 return regmap_write(pcf85063->regmap, PCF85063_REG_OFFSET, reg); 286 } 287 288 static int pcf85063_ioctl(struct device *dev, unsigned int cmd, 289 unsigned long arg) 290 { 291 struct pcf85063 *pcf85063 = dev_get_drvdata(dev); 292 int status, ret = 0; 293 294 switch (cmd) { 295 case RTC_VL_READ: 296 ret = regmap_read(pcf85063->regmap, PCF85063_REG_SC, &status); 297 if (ret < 0) 298 return ret; 299 300 status = status & PCF85063_REG_SC_OS ? RTC_VL_DATA_INVALID : 0; 301 302 return put_user(status, (unsigned int __user *)arg); 303 304 default: 305 return -ENOIOCTLCMD; 306 } 307 } 308 309 static const struct rtc_class_ops pcf85063_rtc_ops = { 310 .read_time = pcf85063_rtc_read_time, 311 .set_time = pcf85063_rtc_set_time, 312 .read_offset = pcf85063_read_offset, 313 .set_offset = pcf85063_set_offset, 314 .ioctl = pcf85063_ioctl, 315 }; 316 317 static const struct rtc_class_ops pcf85063_rtc_ops_alarm = { 318 .read_time = pcf85063_rtc_read_time, 319 .set_time = pcf85063_rtc_set_time, 320 .read_offset = pcf85063_read_offset, 321 .set_offset = pcf85063_set_offset, 322 .read_alarm = pcf85063_rtc_read_alarm, 323 .set_alarm = pcf85063_rtc_set_alarm, 324 .alarm_irq_enable = pcf85063_rtc_alarm_irq_enable, 325 .ioctl = pcf85063_ioctl, 326 }; 327 328 static int pcf85063_nvmem_read(void *priv, unsigned int offset, 329 void *val, size_t bytes) 330 { 331 return regmap_read(priv, PCF85063_REG_RAM, val); 332 } 333 334 static int pcf85063_nvmem_write(void *priv, unsigned int offset, 335 void *val, size_t bytes) 336 { 337 return regmap_write(priv, PCF85063_REG_RAM, *(u8 *)val); 338 } 339 340 static int pcf85063_load_capacitance(struct pcf85063 *pcf85063, 341 const struct device_node *np, 342 unsigned int force_cap) 343 { 344 u32 load = 7000; 345 u8 reg = 0; 346 347 if (force_cap) 348 load = force_cap; 349 else 350 of_property_read_u32(np, "quartz-load-femtofarads", &load); 351 352 switch (load) { 353 default: 354 dev_warn(&pcf85063->rtc->dev, "Unknown quartz-load-femtofarads value: %d. Assuming 7000", 355 load); 356 /* fall through */ 357 case 7000: 358 break; 359 case 12500: 360 reg = PCF85063_REG_CTRL1_CAP_SEL; 361 break; 362 } 363 364 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL1, 365 PCF85063_REG_CTRL1_CAP_SEL, reg); 366 } 367 368 #ifdef CONFIG_COMMON_CLK 369 /* 370 * Handling of the clkout 371 */ 372 373 #define clkout_hw_to_pcf85063(_hw) container_of(_hw, struct pcf85063, clkout_hw) 374 375 static int clkout_rates[] = { 376 32768, 377 16384, 378 8192, 379 4096, 380 2048, 381 1024, 382 1, 383 0 384 }; 385 386 static unsigned long pcf85063_clkout_recalc_rate(struct clk_hw *hw, 387 unsigned long parent_rate) 388 { 389 struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw); 390 unsigned int buf; 391 int ret = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &buf); 392 393 if (ret < 0) 394 return 0; 395 396 buf &= PCF85063_REG_CLKO_F_MASK; 397 return clkout_rates[buf]; 398 } 399 400 static long pcf85063_clkout_round_rate(struct clk_hw *hw, unsigned long rate, 401 unsigned long *prate) 402 { 403 int i; 404 405 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++) 406 if (clkout_rates[i] <= rate) 407 return clkout_rates[i]; 408 409 return 0; 410 } 411 412 static int pcf85063_clkout_set_rate(struct clk_hw *hw, unsigned long rate, 413 unsigned long parent_rate) 414 { 415 struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw); 416 int i; 417 418 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++) 419 if (clkout_rates[i] == rate) 420 return regmap_update_bits(pcf85063->regmap, 421 PCF85063_REG_CTRL2, 422 PCF85063_REG_CLKO_F_MASK, i); 423 424 return -EINVAL; 425 } 426 427 static int pcf85063_clkout_control(struct clk_hw *hw, bool enable) 428 { 429 struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw); 430 unsigned int buf; 431 int ret; 432 433 ret = regmap_read(pcf85063->regmap, PCF85063_REG_OFFSET, &buf); 434 if (ret < 0) 435 return ret; 436 buf &= PCF85063_REG_CLKO_F_MASK; 437 438 if (enable) { 439 if (buf == PCF85063_REG_CLKO_F_OFF) 440 buf = PCF85063_REG_CLKO_F_32768HZ; 441 else 442 return 0; 443 } else { 444 if (buf != PCF85063_REG_CLKO_F_OFF) 445 buf = PCF85063_REG_CLKO_F_OFF; 446 else 447 return 0; 448 } 449 450 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2, 451 PCF85063_REG_CLKO_F_MASK, buf); 452 } 453 454 static int pcf85063_clkout_prepare(struct clk_hw *hw) 455 { 456 return pcf85063_clkout_control(hw, 1); 457 } 458 459 static void pcf85063_clkout_unprepare(struct clk_hw *hw) 460 { 461 pcf85063_clkout_control(hw, 0); 462 } 463 464 static int pcf85063_clkout_is_prepared(struct clk_hw *hw) 465 { 466 struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw); 467 unsigned int buf; 468 int ret = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &buf); 469 470 if (ret < 0) 471 return 0; 472 473 return (buf & PCF85063_REG_CLKO_F_MASK) != PCF85063_REG_CLKO_F_OFF; 474 } 475 476 static const struct clk_ops pcf85063_clkout_ops = { 477 .prepare = pcf85063_clkout_prepare, 478 .unprepare = pcf85063_clkout_unprepare, 479 .is_prepared = pcf85063_clkout_is_prepared, 480 .recalc_rate = pcf85063_clkout_recalc_rate, 481 .round_rate = pcf85063_clkout_round_rate, 482 .set_rate = pcf85063_clkout_set_rate, 483 }; 484 485 static struct clk *pcf85063_clkout_register_clk(struct pcf85063 *pcf85063) 486 { 487 struct clk *clk; 488 struct clk_init_data init; 489 490 init.name = "pcf85063-clkout"; 491 init.ops = &pcf85063_clkout_ops; 492 init.flags = 0; 493 init.parent_names = NULL; 494 init.num_parents = 0; 495 pcf85063->clkout_hw.init = &init; 496 497 /* optional override of the clockname */ 498 of_property_read_string(pcf85063->rtc->dev.of_node, 499 "clock-output-names", &init.name); 500 501 /* register the clock */ 502 clk = devm_clk_register(&pcf85063->rtc->dev, &pcf85063->clkout_hw); 503 504 if (!IS_ERR(clk)) 505 of_clk_add_provider(pcf85063->rtc->dev.of_node, 506 of_clk_src_simple_get, clk); 507 508 return clk; 509 } 510 #endif 511 512 static const struct pcf85063_config pcf85063a_config = { 513 .regmap = { 514 .reg_bits = 8, 515 .val_bits = 8, 516 .max_register = 0x11, 517 }, 518 .has_alarms = 1, 519 }; 520 521 static const struct pcf85063_config pcf85063tp_config = { 522 .regmap = { 523 .reg_bits = 8, 524 .val_bits = 8, 525 .max_register = 0x0a, 526 }, 527 }; 528 529 static const struct pcf85063_config rv8263_config = { 530 .regmap = { 531 .reg_bits = 8, 532 .val_bits = 8, 533 .max_register = 0x11, 534 }, 535 .has_alarms = 1, 536 .force_cap_7000 = 1, 537 }; 538 539 static int pcf85063_probe(struct i2c_client *client) 540 { 541 struct pcf85063 *pcf85063; 542 unsigned int tmp; 543 int err; 544 const struct pcf85063_config *config = &pcf85063tp_config; 545 const void *data = of_device_get_match_data(&client->dev); 546 struct nvmem_config nvmem_cfg = { 547 .name = "pcf85063_nvram", 548 .reg_read = pcf85063_nvmem_read, 549 .reg_write = pcf85063_nvmem_write, 550 .type = NVMEM_TYPE_BATTERY_BACKED, 551 .size = 1, 552 }; 553 554 dev_dbg(&client->dev, "%s\n", __func__); 555 556 pcf85063 = devm_kzalloc(&client->dev, sizeof(struct pcf85063), 557 GFP_KERNEL); 558 if (!pcf85063) 559 return -ENOMEM; 560 561 if (data) 562 config = data; 563 564 pcf85063->regmap = devm_regmap_init_i2c(client, &config->regmap); 565 if (IS_ERR(pcf85063->regmap)) 566 return PTR_ERR(pcf85063->regmap); 567 568 i2c_set_clientdata(client, pcf85063); 569 570 err = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL1, &tmp); 571 if (err) { 572 dev_err(&client->dev, "RTC chip is not present\n"); 573 return err; 574 } 575 576 pcf85063->rtc = devm_rtc_allocate_device(&client->dev); 577 if (IS_ERR(pcf85063->rtc)) 578 return PTR_ERR(pcf85063->rtc); 579 580 err = pcf85063_load_capacitance(pcf85063, client->dev.of_node, 581 config->force_cap_7000 ? 7000 : 0); 582 if (err < 0) 583 dev_warn(&client->dev, "failed to set xtal load capacitance: %d", 584 err); 585 586 pcf85063->rtc->ops = &pcf85063_rtc_ops; 587 pcf85063->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; 588 pcf85063->rtc->range_max = RTC_TIMESTAMP_END_2099; 589 pcf85063->rtc->uie_unsupported = 1; 590 591 if (config->has_alarms && client->irq > 0) { 592 err = devm_request_threaded_irq(&client->dev, client->irq, 593 NULL, pcf85063_rtc_handle_irq, 594 IRQF_TRIGGER_LOW | IRQF_ONESHOT, 595 "pcf85063", pcf85063); 596 if (err) { 597 dev_warn(&pcf85063->rtc->dev, 598 "unable to request IRQ, alarms disabled\n"); 599 } else { 600 pcf85063->rtc->ops = &pcf85063_rtc_ops_alarm; 601 device_init_wakeup(&client->dev, true); 602 err = dev_pm_set_wake_irq(&client->dev, client->irq); 603 if (err) 604 dev_err(&pcf85063->rtc->dev, 605 "failed to enable irq wake\n"); 606 } 607 } 608 609 nvmem_cfg.priv = pcf85063->regmap; 610 rtc_nvmem_register(pcf85063->rtc, &nvmem_cfg); 611 612 #ifdef CONFIG_COMMON_CLK 613 /* register clk in common clk framework */ 614 pcf85063_clkout_register_clk(pcf85063); 615 #endif 616 617 return rtc_register_device(pcf85063->rtc); 618 } 619 620 #ifdef CONFIG_OF 621 static const struct of_device_id pcf85063_of_match[] = { 622 { .compatible = "nxp,pcf85063", .data = &pcf85063tp_config }, 623 { .compatible = "nxp,pcf85063tp", .data = &pcf85063tp_config }, 624 { .compatible = "nxp,pcf85063a", .data = &pcf85063a_config }, 625 { .compatible = "microcrystal,rv8263", .data = &rv8263_config }, 626 {} 627 }; 628 MODULE_DEVICE_TABLE(of, pcf85063_of_match); 629 #endif 630 631 static struct i2c_driver pcf85063_driver = { 632 .driver = { 633 .name = "rtc-pcf85063", 634 .of_match_table = of_match_ptr(pcf85063_of_match), 635 }, 636 .probe_new = pcf85063_probe, 637 }; 638 639 module_i2c_driver(pcf85063_driver); 640 641 MODULE_AUTHOR("Søren Andersen <san@rosetechnology.dk>"); 642 MODULE_DESCRIPTION("PCF85063 RTC driver"); 643 MODULE_LICENSE("GPL"); 644