1 /* rtc-ds1343.c 2 * 3 * Driver for Dallas Semiconductor DS1343 Low Current, SPI Compatible 4 * Real Time Clock 5 * 6 * Author : Raghavendra Chandra Ganiga <[email protected]> 7 * Ankur Srivastava <[email protected]> : DS1343 Nvram Support 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 as 11 * published by the Free Software Foundation. 12 * 13 */ 14 15 #include <linux/init.h> 16 #include <linux/module.h> 17 #include <linux/interrupt.h> 18 #include <linux/device.h> 19 #include <linux/spi/spi.h> 20 #include <linux/regmap.h> 21 #include <linux/rtc.h> 22 #include <linux/bcd.h> 23 #include <linux/pm.h> 24 #include <linux/pm_wakeirq.h> 25 #include <linux/slab.h> 26 27 #define DALLAS_MAXIM_DS1343 0 28 #define DALLAS_MAXIM_DS1344 1 29 30 /* RTC DS1343 Registers */ 31 #define DS1343_SECONDS_REG 0x00 32 #define DS1343_MINUTES_REG 0x01 33 #define DS1343_HOURS_REG 0x02 34 #define DS1343_DAY_REG 0x03 35 #define DS1343_DATE_REG 0x04 36 #define DS1343_MONTH_REG 0x05 37 #define DS1343_YEAR_REG 0x06 38 #define DS1343_ALM0_SEC_REG 0x07 39 #define DS1343_ALM0_MIN_REG 0x08 40 #define DS1343_ALM0_HOUR_REG 0x09 41 #define DS1343_ALM0_DAY_REG 0x0A 42 #define DS1343_ALM1_SEC_REG 0x0B 43 #define DS1343_ALM1_MIN_REG 0x0C 44 #define DS1343_ALM1_HOUR_REG 0x0D 45 #define DS1343_ALM1_DAY_REG 0x0E 46 #define DS1343_CONTROL_REG 0x0F 47 #define DS1343_STATUS_REG 0x10 48 #define DS1343_TRICKLE_REG 0x11 49 #define DS1343_NVRAM 0x20 50 51 #define DS1343_NVRAM_LEN 96 52 53 /* DS1343 Control Registers bits */ 54 #define DS1343_EOSC 0x80 55 #define DS1343_DOSF 0x20 56 #define DS1343_EGFIL 0x10 57 #define DS1343_SQW 0x08 58 #define DS1343_INTCN 0x04 59 #define DS1343_A1IE 0x02 60 #define DS1343_A0IE 0x01 61 62 /* DS1343 Status Registers bits */ 63 #define DS1343_OSF 0x80 64 #define DS1343_IRQF1 0x02 65 #define DS1343_IRQF0 0x01 66 67 /* DS1343 Trickle Charger Registers bits */ 68 #define DS1343_TRICKLE_MAGIC 0xa0 69 #define DS1343_TRICKLE_DS1 0x08 70 #define DS1343_TRICKLE_1K 0x01 71 #define DS1343_TRICKLE_2K 0x02 72 #define DS1343_TRICKLE_4K 0x03 73 74 static const struct spi_device_id ds1343_id[] = { 75 { "ds1343", DALLAS_MAXIM_DS1343 }, 76 { "ds1344", DALLAS_MAXIM_DS1344 }, 77 { } 78 }; 79 MODULE_DEVICE_TABLE(spi, ds1343_id); 80 81 struct ds1343_priv { 82 struct spi_device *spi; 83 struct rtc_device *rtc; 84 struct regmap *map; 85 struct mutex mutex; 86 unsigned int irqen; 87 int irq; 88 int alarm_sec; 89 int alarm_min; 90 int alarm_hour; 91 int alarm_mday; 92 }; 93 94 static int ds1343_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 95 { 96 switch (cmd) { 97 #ifdef RTC_SET_CHARGE 98 case RTC_SET_CHARGE: 99 { 100 int val; 101 102 if (copy_from_user(&val, (int __user *)arg, sizeof(int))) 103 return -EFAULT; 104 105 return regmap_write(priv->map, DS1343_TRICKLE_REG, val); 106 } 107 break; 108 #endif 109 } 110 111 return -ENOIOCTLCMD; 112 } 113 114 static ssize_t ds1343_show_glitchfilter(struct device *dev, 115 struct device_attribute *attr, char *buf) 116 { 117 struct ds1343_priv *priv = dev_get_drvdata(dev); 118 int glitch_filt_status, data; 119 120 regmap_read(priv->map, DS1343_CONTROL_REG, &data); 121 122 glitch_filt_status = !!(data & DS1343_EGFIL); 123 124 if (glitch_filt_status) 125 return sprintf(buf, "enabled\n"); 126 else 127 return sprintf(buf, "disabled\n"); 128 } 129 130 static ssize_t ds1343_store_glitchfilter(struct device *dev, 131 struct device_attribute *attr, 132 const char *buf, size_t count) 133 { 134 struct ds1343_priv *priv = dev_get_drvdata(dev); 135 int data; 136 137 regmap_read(priv->map, DS1343_CONTROL_REG, &data); 138 139 if (strncmp(buf, "enabled", 7) == 0) 140 data |= DS1343_EGFIL; 141 142 else if (strncmp(buf, "disabled", 8) == 0) 143 data &= ~(DS1343_EGFIL); 144 145 else 146 return -EINVAL; 147 148 regmap_write(priv->map, DS1343_CONTROL_REG, data); 149 150 return count; 151 } 152 153 static DEVICE_ATTR(glitch_filter, S_IRUGO | S_IWUSR, ds1343_show_glitchfilter, 154 ds1343_store_glitchfilter); 155 156 static ssize_t ds1343_nvram_write(struct file *filp, struct kobject *kobj, 157 struct bin_attribute *attr, 158 char *buf, loff_t off, size_t count) 159 { 160 int ret; 161 unsigned char address; 162 struct device *dev = kobj_to_dev(kobj); 163 struct ds1343_priv *priv = dev_get_drvdata(dev); 164 165 address = DS1343_NVRAM + off; 166 167 ret = regmap_bulk_write(priv->map, address, buf, count); 168 if (ret < 0) 169 dev_err(&priv->spi->dev, "Error in nvram write %d", ret); 170 171 return (ret < 0) ? ret : count; 172 } 173 174 175 static ssize_t ds1343_nvram_read(struct file *filp, struct kobject *kobj, 176 struct bin_attribute *attr, 177 char *buf, loff_t off, size_t count) 178 { 179 int ret; 180 unsigned char address; 181 struct device *dev = kobj_to_dev(kobj); 182 struct ds1343_priv *priv = dev_get_drvdata(dev); 183 184 address = DS1343_NVRAM + off; 185 186 ret = regmap_bulk_read(priv->map, address, buf, count); 187 if (ret < 0) 188 dev_err(&priv->spi->dev, "Error in nvram read %d\n", ret); 189 190 return (ret < 0) ? ret : count; 191 } 192 193 194 static struct bin_attribute nvram_attr = { 195 .attr.name = "nvram", 196 .attr.mode = S_IRUGO | S_IWUSR, 197 .read = ds1343_nvram_read, 198 .write = ds1343_nvram_write, 199 .size = DS1343_NVRAM_LEN, 200 }; 201 202 static ssize_t ds1343_show_tricklecharger(struct device *dev, 203 struct device_attribute *attr, char *buf) 204 { 205 struct ds1343_priv *priv = dev_get_drvdata(dev); 206 int data; 207 char *diodes = "disabled", *resistors = " "; 208 209 regmap_read(priv->map, DS1343_TRICKLE_REG, &data); 210 211 if ((data & 0xf0) == DS1343_TRICKLE_MAGIC) { 212 switch (data & 0x0c) { 213 case DS1343_TRICKLE_DS1: 214 diodes = "one diode,"; 215 break; 216 217 default: 218 diodes = "no diode,"; 219 break; 220 } 221 222 switch (data & 0x03) { 223 case DS1343_TRICKLE_1K: 224 resistors = "1k Ohm"; 225 break; 226 227 case DS1343_TRICKLE_2K: 228 resistors = "2k Ohm"; 229 break; 230 231 case DS1343_TRICKLE_4K: 232 resistors = "4k Ohm"; 233 break; 234 235 default: 236 diodes = "disabled"; 237 break; 238 } 239 } 240 241 return sprintf(buf, "%s %s\n", diodes, resistors); 242 } 243 244 static DEVICE_ATTR(trickle_charger, S_IRUGO, ds1343_show_tricklecharger, NULL); 245 246 static int ds1343_sysfs_register(struct device *dev) 247 { 248 int err; 249 250 err = device_create_file(dev, &dev_attr_glitch_filter); 251 if (err) 252 return err; 253 254 err = device_create_file(dev, &dev_attr_trickle_charger); 255 if (err) 256 goto error1; 257 258 err = device_create_bin_file(dev, &nvram_attr); 259 if (!err) 260 return 0; 261 262 device_remove_file(dev, &dev_attr_trickle_charger); 263 264 error1: 265 device_remove_file(dev, &dev_attr_glitch_filter); 266 267 return err; 268 } 269 270 static void ds1343_sysfs_unregister(struct device *dev) 271 { 272 device_remove_file(dev, &dev_attr_glitch_filter); 273 device_remove_file(dev, &dev_attr_trickle_charger); 274 device_remove_bin_file(dev, &nvram_attr); 275 } 276 277 static int ds1343_read_time(struct device *dev, struct rtc_time *dt) 278 { 279 struct ds1343_priv *priv = dev_get_drvdata(dev); 280 unsigned char buf[7]; 281 int res; 282 283 res = regmap_bulk_read(priv->map, DS1343_SECONDS_REG, buf, 7); 284 if (res) 285 return res; 286 287 dt->tm_sec = bcd2bin(buf[0]); 288 dt->tm_min = bcd2bin(buf[1]); 289 dt->tm_hour = bcd2bin(buf[2] & 0x3F); 290 dt->tm_wday = bcd2bin(buf[3]) - 1; 291 dt->tm_mday = bcd2bin(buf[4]); 292 dt->tm_mon = bcd2bin(buf[5] & 0x1F) - 1; 293 dt->tm_year = bcd2bin(buf[6]) + 100; /* year offset from 1900 */ 294 295 return rtc_valid_tm(dt); 296 } 297 298 static int ds1343_set_time(struct device *dev, struct rtc_time *dt) 299 { 300 struct ds1343_priv *priv = dev_get_drvdata(dev); 301 int res; 302 303 res = regmap_write(priv->map, DS1343_SECONDS_REG, 304 bin2bcd(dt->tm_sec)); 305 if (res) 306 return res; 307 308 res = regmap_write(priv->map, DS1343_MINUTES_REG, 309 bin2bcd(dt->tm_min)); 310 if (res) 311 return res; 312 313 res = regmap_write(priv->map, DS1343_HOURS_REG, 314 bin2bcd(dt->tm_hour) & 0x3F); 315 if (res) 316 return res; 317 318 res = regmap_write(priv->map, DS1343_DAY_REG, 319 bin2bcd(dt->tm_wday + 1)); 320 if (res) 321 return res; 322 323 res = regmap_write(priv->map, DS1343_DATE_REG, 324 bin2bcd(dt->tm_mday)); 325 if (res) 326 return res; 327 328 res = regmap_write(priv->map, DS1343_MONTH_REG, 329 bin2bcd(dt->tm_mon + 1)); 330 if (res) 331 return res; 332 333 dt->tm_year %= 100; 334 335 res = regmap_write(priv->map, DS1343_YEAR_REG, 336 bin2bcd(dt->tm_year)); 337 if (res) 338 return res; 339 340 return 0; 341 } 342 343 static int ds1343_update_alarm(struct device *dev) 344 { 345 struct ds1343_priv *priv = dev_get_drvdata(dev); 346 unsigned int control, stat; 347 unsigned char buf[4]; 348 int res = 0; 349 350 res = regmap_read(priv->map, DS1343_CONTROL_REG, &control); 351 if (res) 352 return res; 353 354 res = regmap_read(priv->map, DS1343_STATUS_REG, &stat); 355 if (res) 356 return res; 357 358 control &= ~(DS1343_A0IE); 359 stat &= ~(DS1343_IRQF0); 360 361 res = regmap_write(priv->map, DS1343_CONTROL_REG, control); 362 if (res) 363 return res; 364 365 res = regmap_write(priv->map, DS1343_STATUS_REG, stat); 366 if (res) 367 return res; 368 369 buf[0] = priv->alarm_sec < 0 || (priv->irqen & RTC_UF) ? 370 0x80 : bin2bcd(priv->alarm_sec) & 0x7F; 371 buf[1] = priv->alarm_min < 0 || (priv->irqen & RTC_UF) ? 372 0x80 : bin2bcd(priv->alarm_min) & 0x7F; 373 buf[2] = priv->alarm_hour < 0 || (priv->irqen & RTC_UF) ? 374 0x80 : bin2bcd(priv->alarm_hour) & 0x3F; 375 buf[3] = priv->alarm_mday < 0 || (priv->irqen & RTC_UF) ? 376 0x80 : bin2bcd(priv->alarm_mday) & 0x7F; 377 378 res = regmap_bulk_write(priv->map, DS1343_ALM0_SEC_REG, buf, 4); 379 if (res) 380 return res; 381 382 if (priv->irqen) { 383 control |= DS1343_A0IE; 384 res = regmap_write(priv->map, DS1343_CONTROL_REG, control); 385 } 386 387 return res; 388 } 389 390 static int ds1343_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 391 { 392 struct ds1343_priv *priv = dev_get_drvdata(dev); 393 int res = 0; 394 unsigned int stat; 395 396 if (priv->irq <= 0) 397 return -EINVAL; 398 399 mutex_lock(&priv->mutex); 400 401 res = regmap_read(priv->map, DS1343_STATUS_REG, &stat); 402 if (res) 403 goto out; 404 405 alarm->enabled = !!(priv->irqen & RTC_AF); 406 alarm->pending = !!(stat & DS1343_IRQF0); 407 408 alarm->time.tm_sec = priv->alarm_sec < 0 ? 0 : priv->alarm_sec; 409 alarm->time.tm_min = priv->alarm_min < 0 ? 0 : priv->alarm_min; 410 alarm->time.tm_hour = priv->alarm_hour < 0 ? 0 : priv->alarm_hour; 411 alarm->time.tm_mday = priv->alarm_mday < 0 ? 0 : priv->alarm_mday; 412 413 out: 414 mutex_unlock(&priv->mutex); 415 return res; 416 } 417 418 static int ds1343_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 419 { 420 struct ds1343_priv *priv = dev_get_drvdata(dev); 421 int res = 0; 422 423 if (priv->irq <= 0) 424 return -EINVAL; 425 426 mutex_lock(&priv->mutex); 427 428 priv->alarm_sec = alarm->time.tm_sec; 429 priv->alarm_min = alarm->time.tm_min; 430 priv->alarm_hour = alarm->time.tm_hour; 431 priv->alarm_mday = alarm->time.tm_mday; 432 433 if (alarm->enabled) 434 priv->irqen |= RTC_AF; 435 436 res = ds1343_update_alarm(dev); 437 438 mutex_unlock(&priv->mutex); 439 440 return res; 441 } 442 443 static int ds1343_alarm_irq_enable(struct device *dev, unsigned int enabled) 444 { 445 struct ds1343_priv *priv = dev_get_drvdata(dev); 446 int res = 0; 447 448 if (priv->irq <= 0) 449 return -EINVAL; 450 451 mutex_lock(&priv->mutex); 452 453 if (enabled) 454 priv->irqen |= RTC_AF; 455 else 456 priv->irqen &= ~RTC_AF; 457 458 res = ds1343_update_alarm(dev); 459 460 mutex_unlock(&priv->mutex); 461 462 return res; 463 } 464 465 static irqreturn_t ds1343_thread(int irq, void *dev_id) 466 { 467 struct ds1343_priv *priv = dev_id; 468 unsigned int stat, control; 469 int res = 0; 470 471 mutex_lock(&priv->mutex); 472 473 res = regmap_read(priv->map, DS1343_STATUS_REG, &stat); 474 if (res) 475 goto out; 476 477 if (stat & DS1343_IRQF0) { 478 stat &= ~DS1343_IRQF0; 479 regmap_write(priv->map, DS1343_STATUS_REG, stat); 480 481 res = regmap_read(priv->map, DS1343_CONTROL_REG, &control); 482 if (res) 483 goto out; 484 485 control &= ~DS1343_A0IE; 486 regmap_write(priv->map, DS1343_CONTROL_REG, control); 487 488 rtc_update_irq(priv->rtc, 1, RTC_AF | RTC_IRQF); 489 } 490 491 out: 492 mutex_unlock(&priv->mutex); 493 return IRQ_HANDLED; 494 } 495 496 static const struct rtc_class_ops ds1343_rtc_ops = { 497 .ioctl = ds1343_ioctl, 498 .read_time = ds1343_read_time, 499 .set_time = ds1343_set_time, 500 .read_alarm = ds1343_read_alarm, 501 .set_alarm = ds1343_set_alarm, 502 .alarm_irq_enable = ds1343_alarm_irq_enable, 503 }; 504 505 static int ds1343_probe(struct spi_device *spi) 506 { 507 struct ds1343_priv *priv; 508 struct regmap_config config = { .reg_bits = 8, .val_bits = 8, 509 .write_flag_mask = 0x80, }; 510 unsigned int data; 511 int res; 512 513 priv = devm_kzalloc(&spi->dev, sizeof(struct ds1343_priv), GFP_KERNEL); 514 if (!priv) 515 return -ENOMEM; 516 517 priv->spi = spi; 518 mutex_init(&priv->mutex); 519 520 /* RTC DS1347 works in spi mode 3 and 521 * its chip select is active high 522 */ 523 spi->mode = SPI_MODE_3 | SPI_CS_HIGH; 524 spi->bits_per_word = 8; 525 res = spi_setup(spi); 526 if (res) 527 return res; 528 529 spi_set_drvdata(spi, priv); 530 531 priv->map = devm_regmap_init_spi(spi, &config); 532 533 if (IS_ERR(priv->map)) { 534 dev_err(&spi->dev, "spi regmap init failed for rtc ds1343\n"); 535 return PTR_ERR(priv->map); 536 } 537 538 res = regmap_read(priv->map, DS1343_SECONDS_REG, &data); 539 if (res) 540 return res; 541 542 regmap_read(priv->map, DS1343_CONTROL_REG, &data); 543 data |= DS1343_INTCN; 544 data &= ~(DS1343_EOSC | DS1343_A1IE | DS1343_A0IE); 545 regmap_write(priv->map, DS1343_CONTROL_REG, data); 546 547 regmap_read(priv->map, DS1343_STATUS_REG, &data); 548 data &= ~(DS1343_OSF | DS1343_IRQF1 | DS1343_IRQF0); 549 regmap_write(priv->map, DS1343_STATUS_REG, data); 550 551 priv->rtc = devm_rtc_allocate_device(&spi->dev); 552 if (IS_ERR(priv->rtc)) 553 return PTR_ERR(priv->rtc); 554 555 priv->rtc->ops = &ds1343_rtc_ops; 556 557 res = rtc_register_device(priv->rtc); 558 if (res) 559 return res; 560 561 priv->irq = spi->irq; 562 563 if (priv->irq >= 0) { 564 res = devm_request_threaded_irq(&spi->dev, spi->irq, NULL, 565 ds1343_thread, IRQF_ONESHOT, 566 "ds1343", priv); 567 if (res) { 568 priv->irq = -1; 569 dev_err(&spi->dev, 570 "unable to request irq for rtc ds1343\n"); 571 } else { 572 device_init_wakeup(&spi->dev, true); 573 dev_pm_set_wake_irq(&spi->dev, spi->irq); 574 } 575 } 576 577 res = ds1343_sysfs_register(&spi->dev); 578 if (res) 579 dev_err(&spi->dev, 580 "unable to create sysfs entries for rtc ds1343\n"); 581 582 return 0; 583 } 584 585 static int ds1343_remove(struct spi_device *spi) 586 { 587 struct ds1343_priv *priv = spi_get_drvdata(spi); 588 589 if (spi->irq) { 590 mutex_lock(&priv->mutex); 591 priv->irqen &= ~RTC_AF; 592 mutex_unlock(&priv->mutex); 593 594 dev_pm_clear_wake_irq(&spi->dev); 595 device_init_wakeup(&spi->dev, false); 596 devm_free_irq(&spi->dev, spi->irq, priv); 597 } 598 599 spi_set_drvdata(spi, NULL); 600 601 ds1343_sysfs_unregister(&spi->dev); 602 603 return 0; 604 } 605 606 #ifdef CONFIG_PM_SLEEP 607 608 static int ds1343_suspend(struct device *dev) 609 { 610 struct spi_device *spi = to_spi_device(dev); 611 612 if (spi->irq >= 0 && device_may_wakeup(dev)) 613 enable_irq_wake(spi->irq); 614 615 return 0; 616 } 617 618 static int ds1343_resume(struct device *dev) 619 { 620 struct spi_device *spi = to_spi_device(dev); 621 622 if (spi->irq >= 0 && device_may_wakeup(dev)) 623 disable_irq_wake(spi->irq); 624 625 return 0; 626 } 627 628 #endif 629 630 static SIMPLE_DEV_PM_OPS(ds1343_pm, ds1343_suspend, ds1343_resume); 631 632 static struct spi_driver ds1343_driver = { 633 .driver = { 634 .name = "ds1343", 635 .pm = &ds1343_pm, 636 }, 637 .probe = ds1343_probe, 638 .remove = ds1343_remove, 639 .id_table = ds1343_id, 640 }; 641 642 module_spi_driver(ds1343_driver); 643 644 MODULE_DESCRIPTION("DS1343 RTC SPI Driver"); 645 MODULE_AUTHOR("Raghavendra Chandra Ganiga <[email protected]>," 646 "Ankur Srivastava <[email protected]>"); 647 MODULE_LICENSE("GPL v2"); 648