drivers/rtc/rtc-ds1343.c

   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 <ravi23ganiga@gmail.com>
   7  *          Ankur Srivastava <sankurece@gmail.com> : 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 int ds1343_nvram_write(void *priv, unsigned int off, void *val,
 157                               size_t bytes)
 158 {
 159         struct ds1343_priv *ds1343 = priv;
 160
 161         return regmap_bulk_write(ds1343->map, DS1343_NVRAM + off, val, bytes);
 162 }
 163
 164 static int ds1343_nvram_read(void *priv, unsigned int off, void *val,
 165                              size_t bytes)
 166 {
 167         struct ds1343_priv *ds1343 = priv;
 168
 169         return regmap_bulk_read(ds1343->map, DS1343_NVRAM + off, val, bytes);
 170 }
 171
 172 static ssize_t ds1343_show_tricklecharger(struct device *dev,
 173                                 struct device_attribute *attr, char *buf)
 174 {
 175         struct ds1343_priv *priv = dev_get_drvdata(dev);
 176         int data;
 177         char *diodes = "disabled", *resistors = " ";
 178
 179         regmap_read(priv->map, DS1343_TRICKLE_REG, &data);
 180
 181         if ((data & 0xf0) == DS1343_TRICKLE_MAGIC) {
 182                 switch (data & 0x0c) {
 183                 case DS1343_TRICKLE_DS1:
 184                         diodes = "one diode,";
 185                         break;
 186
 187                 default:
 188                         diodes = "no diode,";
 189                         break;
 190                 }
 191
 192                 switch (data & 0x03) {
 193                 case DS1343_TRICKLE_1K:
 194                         resistors = "1k Ohm";
 195                         break;
 196
 197                 case DS1343_TRICKLE_2K:
 198                         resistors = "2k Ohm";
 199                         break;
 200
 201                 case DS1343_TRICKLE_4K:
 202                         resistors = "4k Ohm";
 203                         break;
 204
 205                 default:
 206                         diodes = "disabled";
 207                         break;
 208                 }
 209         }
 210
 211         return sprintf(buf, "%s %s\n", diodes, resistors);
 212 }
 213
 214 static DEVICE_ATTR(trickle_charger, S_IRUGO, ds1343_show_tricklecharger, NULL);
 215
 216 static int ds1343_sysfs_register(struct device *dev)
 217 {
 218         int err;
 219
 220         err = device_create_file(dev, &dev_attr_glitch_filter);
 221         if (err)
 222                 return err;
 223
 224         err = device_create_file(dev, &dev_attr_trickle_charger);
 225         if (!err)
 226                 return 0;
 227
 228         device_remove_file(dev, &dev_attr_glitch_filter);
 229
 230         return err;
 231 }
 232
 233 static void ds1343_sysfs_unregister(struct device *dev)
 234 {
 235         device_remove_file(dev, &dev_attr_glitch_filter);
 236         device_remove_file(dev, &dev_attr_trickle_charger);
 237 }
 238
 239 static int ds1343_read_time(struct device *dev, struct rtc_time *dt)
 240 {
 241         struct ds1343_priv *priv = dev_get_drvdata(dev);
 242         unsigned char buf[7];
 243         int res;
 244
 245         res = regmap_bulk_read(priv->map, DS1343_SECONDS_REG, buf, 7);
 246         if (res)
 247                 return res;
 248
 249         dt->tm_sec      = bcd2bin(buf[0]);
 250         dt->tm_min      = bcd2bin(buf[1]);
 251         dt->tm_hour     = bcd2bin(buf[2] & 0x3F);
 252         dt->tm_wday     = bcd2bin(buf[3]) - 1;
 253         dt->tm_mday     = bcd2bin(buf[4]);
 254         dt->tm_mon      = bcd2bin(buf[5] & 0x1F) - 1;
 255         dt->tm_year     = bcd2bin(buf[6]) + 100; /* year offset from 1900 */
 256
 257         return 0;
 258 }
 259
 260 static int ds1343_set_time(struct device *dev, struct rtc_time *dt)
 261 {
 262         struct ds1343_priv *priv = dev_get_drvdata(dev);
 263         int res;
 264
 265         res = regmap_write(priv->map, DS1343_SECONDS_REG,
 266                                 bin2bcd(dt->tm_sec));
 267         if (res)
 268                 return res;
 269
 270         res = regmap_write(priv->map, DS1343_MINUTES_REG,
 271                                 bin2bcd(dt->tm_min));
 272         if (res)
 273                 return res;
 274
 275         res = regmap_write(priv->map, DS1343_HOURS_REG,
 276                                 bin2bcd(dt->tm_hour) & 0x3F);
 277         if (res)
 278                 return res;
 279
 280         res = regmap_write(priv->map, DS1343_DAY_REG,
 281                                 bin2bcd(dt->tm_wday + 1));
 282         if (res)
 283                 return res;
 284
 285         res = regmap_write(priv->map, DS1343_DATE_REG,
 286                                 bin2bcd(dt->tm_mday));
 287         if (res)
 288                 return res;
 289
 290         res = regmap_write(priv->map, DS1343_MONTH_REG,
 291                                 bin2bcd(dt->tm_mon + 1));
 292         if (res)
 293                 return res;
 294
 295         dt->tm_year %= 100;
 296
 297         res = regmap_write(priv->map, DS1343_YEAR_REG,
 298                                 bin2bcd(dt->tm_year));
 299         if (res)
 300                 return res;
 301
 302         return 0;
 303 }
 304
 305 static int ds1343_update_alarm(struct device *dev)
 306 {
 307         struct ds1343_priv *priv = dev_get_drvdata(dev);
 308         unsigned int control, stat;
 309         unsigned char buf[4];
 310         int res = 0;
 311
 312         res = regmap_read(priv->map, DS1343_CONTROL_REG, &control);
 313         if (res)
 314                 return res;
 315
 316         res = regmap_read(priv->map, DS1343_STATUS_REG, &stat);
 317         if (res)
 318                 return res;
 319
 320         control &= ~(DS1343_A0IE);
 321         stat &= ~(DS1343_IRQF0);
 322
 323         res = regmap_write(priv->map, DS1343_CONTROL_REG, control);
 324         if (res)
 325                 return res;
 326
 327         res = regmap_write(priv->map, DS1343_STATUS_REG, stat);
 328         if (res)
 329                 return res;
 330
 331         buf[0] = priv->alarm_sec < 0 || (priv->irqen & RTC_UF) ?
 332                 0x80 : bin2bcd(priv->alarm_sec) & 0x7F;
 333         buf[1] = priv->alarm_min < 0 || (priv->irqen & RTC_UF) ?
 334                 0x80 : bin2bcd(priv->alarm_min) & 0x7F;
 335         buf[2] = priv->alarm_hour < 0 || (priv->irqen & RTC_UF) ?
 336                 0x80 : bin2bcd(priv->alarm_hour) & 0x3F;
 337         buf[3] = priv->alarm_mday < 0 || (priv->irqen & RTC_UF) ?
 338                 0x80 : bin2bcd(priv->alarm_mday) & 0x7F;
 339
 340         res = regmap_bulk_write(priv->map, DS1343_ALM0_SEC_REG, buf, 4);
 341         if (res)
 342                 return res;
 343
 344         if (priv->irqen) {
 345                 control |= DS1343_A0IE;
 346                 res = regmap_write(priv->map, DS1343_CONTROL_REG, control);
 347         }
 348
 349         return res;
 350 }
 351
 352 static int ds1343_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 353 {
 354         struct ds1343_priv *priv = dev_get_drvdata(dev);
 355         int res = 0;
 356         unsigned int stat;
 357
 358         if (priv->irq <= 0)
 359                 return -EINVAL;
 360
 361         mutex_lock(&priv->mutex);
 362
 363         res = regmap_read(priv->map, DS1343_STATUS_REG, &stat);
 364         if (res)
 365                 goto out;
 366
 367         alarm->enabled = !!(priv->irqen & RTC_AF);
 368         alarm->pending = !!(stat & DS1343_IRQF0);
 369
 370         alarm->time.tm_sec = priv->alarm_sec < 0 ? 0 : priv->alarm_sec;
 371         alarm->time.tm_min = priv->alarm_min < 0 ? 0 : priv->alarm_min;
 372         alarm->time.tm_hour = priv->alarm_hour < 0 ? 0 : priv->alarm_hour;
 373         alarm->time.tm_mday = priv->alarm_mday < 0 ? 0 : priv->alarm_mday;
 374
 375 out:
 376         mutex_unlock(&priv->mutex);
 377         return res;
 378 }
 379
 380 static int ds1343_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 381 {
 382         struct ds1343_priv *priv = dev_get_drvdata(dev);
 383         int res = 0;
 384
 385         if (priv->irq <= 0)
 386                 return -EINVAL;
 387
 388         mutex_lock(&priv->mutex);
 389
 390         priv->alarm_sec = alarm->time.tm_sec;
 391         priv->alarm_min = alarm->time.tm_min;
 392         priv->alarm_hour = alarm->time.tm_hour;
 393         priv->alarm_mday = alarm->time.tm_mday;
 394
 395         if (alarm->enabled)
 396                 priv->irqen |= RTC_AF;
 397
 398         res = ds1343_update_alarm(dev);
 399
 400         mutex_unlock(&priv->mutex);
 401
 402         return res;
 403 }
 404
 405 static int ds1343_alarm_irq_enable(struct device *dev, unsigned int enabled)
 406 {
 407         struct ds1343_priv *priv = dev_get_drvdata(dev);
 408         int res = 0;
 409
 410         if (priv->irq <= 0)
 411                 return -EINVAL;
 412
 413         mutex_lock(&priv->mutex);
 414
 415         if (enabled)
 416                 priv->irqen |= RTC_AF;
 417         else
 418                 priv->irqen &= ~RTC_AF;
 419
 420         res = ds1343_update_alarm(dev);
 421
 422         mutex_unlock(&priv->mutex);
 423
 424         return res;
 425 }
 426
 427 static irqreturn_t ds1343_thread(int irq, void *dev_id)
 428 {
 429         struct ds1343_priv *priv = dev_id;
 430         unsigned int stat, control;
 431         int res = 0;
 432
 433         mutex_lock(&priv->mutex);
 434
 435         res = regmap_read(priv->map, DS1343_STATUS_REG, &stat);
 436         if (res)
 437                 goto out;
 438
 439         if (stat & DS1343_IRQF0) {
 440                 stat &= ~DS1343_IRQF0;
 441                 regmap_write(priv->map, DS1343_STATUS_REG, stat);
 442
 443                 res = regmap_read(priv->map, DS1343_CONTROL_REG, &control);
 444                 if (res)
 445                         goto out;
 446
 447                 control &= ~DS1343_A0IE;
 448                 regmap_write(priv->map, DS1343_CONTROL_REG, control);
 449
 450                 rtc_update_irq(priv->rtc, 1, RTC_AF | RTC_IRQF);
 451         }
 452
 453 out:
 454         mutex_unlock(&priv->mutex);
 455         return IRQ_HANDLED;
 456 }
 457
 458 static const struct rtc_class_ops ds1343_rtc_ops = {
 459         .ioctl          = ds1343_ioctl,
 460         .read_time      = ds1343_read_time,
 461         .set_time       = ds1343_set_time,
 462         .read_alarm     = ds1343_read_alarm,
 463         .set_alarm      = ds1343_set_alarm,
 464         .alarm_irq_enable = ds1343_alarm_irq_enable,
 465 };
 466
 467 static int ds1343_probe(struct spi_device *spi)
 468 {
 469         struct ds1343_priv *priv;
 470         struct regmap_config config = { .reg_bits = 8, .val_bits = 8,
 471                                         .write_flag_mask = 0x80, };
 472         unsigned int data;
 473         int res;
 474         struct nvmem_config nvmem_cfg = {
 475                 .name = "ds1343-",
 476                 .word_size = 1,
 477                 .stride = 1,
 478                 .size = DS1343_NVRAM_LEN,
 479                 .reg_read = ds1343_nvram_read,
 480                 .reg_write = ds1343_nvram_write,
 481         };
 482
 483         priv = devm_kzalloc(&spi->dev, sizeof(struct ds1343_priv), GFP_KERNEL);
 484         if (!priv)
 485                 return -ENOMEM;
 486
 487         priv->spi = spi;
 488         mutex_init(&priv->mutex);
 489
 490         /* RTC DS1347 works in spi mode 3 and
 491          * its chip select is active high
 492          */
 493         spi->mode = SPI_MODE_3 | SPI_CS_HIGH;
 494         spi->bits_per_word = 8;
 495         res = spi_setup(spi);
 496         if (res)
 497                 return res;
 498
 499         spi_set_drvdata(spi, priv);
 500
 501         priv->map = devm_regmap_init_spi(spi, &config);
 502
 503         if (IS_ERR(priv->map)) {
 504                 dev_err(&spi->dev, "spi regmap init failed for rtc ds1343\n");
 505                 return PTR_ERR(priv->map);
 506         }
 507
 508         res = regmap_read(priv->map, DS1343_SECONDS_REG, &data);
 509         if (res)
 510                 return res;
 511
 512         regmap_read(priv->map, DS1343_CONTROL_REG, &data);
 513         data |= DS1343_INTCN;
 514         data &= ~(DS1343_EOSC | DS1343_A1IE | DS1343_A0IE);
 515         regmap_write(priv->map, DS1343_CONTROL_REG, data);
 516
 517         regmap_read(priv->map, DS1343_STATUS_REG, &data);
 518         data &= ~(DS1343_OSF | DS1343_IRQF1 | DS1343_IRQF0);
 519         regmap_write(priv->map, DS1343_STATUS_REG, data);
 520
 521         priv->rtc = devm_rtc_allocate_device(&spi->dev);
 522         if (IS_ERR(priv->rtc))
 523                 return PTR_ERR(priv->rtc);
 524
 525         priv->rtc->nvram_old_abi = true;
 526         priv->rtc->ops = &ds1343_rtc_ops;
 527
 528         res = rtc_register_device(priv->rtc);
 529         if (res)
 530                 return res;
 531
 532         nvmem_cfg.priv = priv;
 533         rtc_nvmem_register(priv->rtc, &nvmem_cfg);
 534
 535         priv->irq = spi->irq;
 536
 537         if (priv->irq >= 0) {
 538                 res = devm_request_threaded_irq(&spi->dev, spi->irq, NULL,
 539                                                 ds1343_thread, IRQF_ONESHOT,
 540                                                 "ds1343", priv);
 541                 if (res) {
 542                         priv->irq = -1;
 543                         dev_err(&spi->dev,
 544                                 "unable to request irq for rtc ds1343\n");
 545                 } else {
 546                         device_init_wakeup(&spi->dev, true);
 547                         dev_pm_set_wake_irq(&spi->dev, spi->irq);
 548                 }
 549         }
 550
 551         res = ds1343_sysfs_register(&spi->dev);
 552         if (res)
 553                 dev_err(&spi->dev,
 554                         "unable to create sysfs entries for rtc ds1343\n");
 555
 556         return 0;
 557 }
 558
 559 static int ds1343_remove(struct spi_device *spi)
 560 {
 561         struct ds1343_priv *priv = spi_get_drvdata(spi);
 562
 563         if (spi->irq) {
 564                 mutex_lock(&priv->mutex);
 565                 priv->irqen &= ~RTC_AF;
 566                 mutex_unlock(&priv->mutex);
 567
 568                 dev_pm_clear_wake_irq(&spi->dev);
 569                 device_init_wakeup(&spi->dev, false);
 570                 devm_free_irq(&spi->dev, spi->irq, priv);
 571         }
 572
 573         spi_set_drvdata(spi, NULL);
 574
 575         ds1343_sysfs_unregister(&spi->dev);
 576
 577         return 0;
 578 }
 579
 580 #ifdef CONFIG_PM_SLEEP
 581
 582 static int ds1343_suspend(struct device *dev)
 583 {
 584         struct spi_device *spi = to_spi_device(dev);
 585
 586         if (spi->irq >= 0 && device_may_wakeup(dev))
 587                 enable_irq_wake(spi->irq);
 588
 589         return 0;
 590 }
 591
 592 static int ds1343_resume(struct device *dev)
 593 {
 594         struct spi_device *spi = to_spi_device(dev);
 595
 596         if (spi->irq >= 0 && device_may_wakeup(dev))
 597                 disable_irq_wake(spi->irq);
 598
 599         return 0;
 600 }
 601
 602 #endif
 603
 604 static SIMPLE_DEV_PM_OPS(ds1343_pm, ds1343_suspend, ds1343_resume);
 605
 606 static struct spi_driver ds1343_driver = {
 607         .driver = {
 608                 .name = "ds1343",
 609                 .pm = &ds1343_pm,
 610         },
 611         .probe = ds1343_probe,
 612         .remove = ds1343_remove,
 613         .id_table = ds1343_id,
 614 };
 615
 616 module_spi_driver(ds1343_driver);
 617
 618 MODULE_DESCRIPTION("DS1343 RTC SPI Driver");
 619 MODULE_AUTHOR("Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>,"
 620                 "Ankur Srivastava <sankurece@gmail.com>");
 621 MODULE_LICENSE("GPL v2");