drivers/rtc/rtc-ds1343.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* rtc-ds1343.c
   3  *
   4  * Driver for Dallas Semiconductor DS1343 Low Current, SPI Compatible
   5  * Real Time Clock
   6  *
   7  * Author : Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>
   8  *          Ankur Srivastava <sankurece@gmail.com> : DS1343 Nvram Support
   9  */
  10
  11 #include <linux/init.h>
  12 #include <linux/module.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/device.h>
  15 #include <linux/spi/spi.h>
  16 #include <linux/regmap.h>
  17 #include <linux/rtc.h>
  18 #include <linux/bcd.h>
  19 #include <linux/pm.h>
  20 #include <linux/pm_wakeirq.h>
  21 #include <linux/slab.h>
  22
  23 #define DALLAS_MAXIM_DS1343     0
  24 #define DALLAS_MAXIM_DS1344     1
  25
  26 /* RTC DS1343 Registers */
  27 #define DS1343_SECONDS_REG      0x00
  28 #define DS1343_MINUTES_REG      0x01
  29 #define DS1343_HOURS_REG        0x02
  30 #define DS1343_DAY_REG          0x03
  31 #define DS1343_DATE_REG         0x04
  32 #define DS1343_MONTH_REG        0x05
  33 #define DS1343_YEAR_REG         0x06
  34 #define DS1343_ALM0_SEC_REG     0x07
  35 #define DS1343_ALM0_MIN_REG     0x08
  36 #define DS1343_ALM0_HOUR_REG    0x09
  37 #define DS1343_ALM0_DAY_REG     0x0A
  38 #define DS1343_ALM1_SEC_REG     0x0B
  39 #define DS1343_ALM1_MIN_REG     0x0C
  40 #define DS1343_ALM1_HOUR_REG    0x0D
  41 #define DS1343_ALM1_DAY_REG     0x0E
  42 #define DS1343_CONTROL_REG      0x0F
  43 #define DS1343_STATUS_REG       0x10
  44 #define DS1343_TRICKLE_REG      0x11
  45 #define DS1343_NVRAM            0x20
  46
  47 #define DS1343_NVRAM_LEN        96
  48
  49 /* DS1343 Control Registers bits */
  50 #define DS1343_EOSC             0x80
  51 #define DS1343_DOSF             0x20
  52 #define DS1343_EGFIL            0x10
  53 #define DS1343_SQW              0x08
  54 #define DS1343_INTCN            0x04
  55 #define DS1343_A1IE             0x02
  56 #define DS1343_A0IE             0x01
  57
  58 /* DS1343 Status Registers bits */
  59 #define DS1343_OSF              0x80
  60 #define DS1343_IRQF1            0x02
  61 #define DS1343_IRQF0            0x01
  62
  63 /* DS1343 Trickle Charger Registers bits */
  64 #define DS1343_TRICKLE_MAGIC    0xa0
  65 #define DS1343_TRICKLE_DS1      0x08
  66 #define DS1343_TRICKLE_1K       0x01
  67 #define DS1343_TRICKLE_2K       0x02
  68 #define DS1343_TRICKLE_4K       0x03
  69
  70 static const struct spi_device_id ds1343_id[] = {
  71         { "ds1343", DALLAS_MAXIM_DS1343 },
  72         { "ds1344", DALLAS_MAXIM_DS1344 },
  73         { }
  74 };
  75 MODULE_DEVICE_TABLE(spi, ds1343_id);
  76
  77 struct ds1343_priv {
  78         struct spi_device *spi;
  79         struct rtc_device *rtc;
  80         struct regmap *map;
  81         struct mutex mutex;
  82         unsigned int irqen;
  83         int irq;
  84         int alarm_sec;
  85         int alarm_min;
  86         int alarm_hour;
  87         int alarm_mday;
  88 };
  89
  90 static int ds1343_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
  91 {
  92         switch (cmd) {
  93 #ifdef RTC_SET_CHARGE
  94         case RTC_SET_CHARGE:
  95         {
  96                 int val;
  97
  98                 if (copy_from_user(&val, (int __user *)arg, sizeof(int)))
  99                         return -EFAULT;
 100
 101                 return regmap_write(priv->map, DS1343_TRICKLE_REG, val);
 102         }
 103         break;
 104 #endif
 105         }
 106
 107         return -ENOIOCTLCMD;
 108 }
 109
 110 static ssize_t ds1343_show_glitchfilter(struct device *dev,
 111                                 struct device_attribute *attr, char *buf)
 112 {
 113         struct ds1343_priv *priv = dev_get_drvdata(dev);
 114         int glitch_filt_status, data;
 115
 116         regmap_read(priv->map, DS1343_CONTROL_REG, &data);
 117
 118         glitch_filt_status = !!(data & DS1343_EGFIL);
 119
 120         if (glitch_filt_status)
 121                 return sprintf(buf, "enabled\n");
 122         else
 123                 return sprintf(buf, "disabled\n");
 124 }
 125
 126 static ssize_t ds1343_store_glitchfilter(struct device *dev,
 127                                         struct device_attribute *attr,
 128                                         const char *buf, size_t count)
 129 {
 130         struct ds1343_priv *priv = dev_get_drvdata(dev);
 131         int data;
 132
 133         regmap_read(priv->map, DS1343_CONTROL_REG, &data);
 134
 135         if (strncmp(buf, "enabled", 7) == 0)
 136                 data |= DS1343_EGFIL;
 137
 138         else if (strncmp(buf, "disabled", 8) == 0)
 139                 data &= ~(DS1343_EGFIL);
 140
 141         else
 142                 return -EINVAL;
 143
 144         regmap_write(priv->map, DS1343_CONTROL_REG, data);
 145
 146         return count;
 147 }
 148
 149 static DEVICE_ATTR(glitch_filter, S_IRUGO | S_IWUSR, ds1343_show_glitchfilter,
 150                         ds1343_store_glitchfilter);
 151
 152 static int ds1343_nvram_write(void *priv, unsigned int off, void *val,
 153                               size_t bytes)
 154 {
 155         struct ds1343_priv *ds1343 = priv;
 156
 157         return regmap_bulk_write(ds1343->map, DS1343_NVRAM + off, val, bytes);
 158 }
 159
 160 static int ds1343_nvram_read(void *priv, unsigned int off, void *val,
 161                              size_t bytes)
 162 {
 163         struct ds1343_priv *ds1343 = priv;
 164
 165         return regmap_bulk_read(ds1343->map, DS1343_NVRAM + off, val, bytes);
 166 }
 167
 168 static ssize_t ds1343_show_tricklecharger(struct device *dev,
 169                                 struct device_attribute *attr, char *buf)
 170 {
 171         struct ds1343_priv *priv = dev_get_drvdata(dev);
 172         int data;
 173         char *diodes = "disabled", *resistors = " ";
 174
 175         regmap_read(priv->map, DS1343_TRICKLE_REG, &data);
 176
 177         if ((data & 0xf0) == DS1343_TRICKLE_MAGIC) {
 178                 switch (data & 0x0c) {
 179                 case DS1343_TRICKLE_DS1:
 180                         diodes = "one diode,";
 181                         break;
 182
 183                 default:
 184                         diodes = "no diode,";
 185                         break;
 186                 }
 187
 188                 switch (data & 0x03) {
 189                 case DS1343_TRICKLE_1K:
 190                         resistors = "1k Ohm";
 191                         break;
 192
 193                 case DS1343_TRICKLE_2K:
 194                         resistors = "2k Ohm";
 195                         break;
 196
 197                 case DS1343_TRICKLE_4K:
 198                         resistors = "4k Ohm";
 199                         break;
 200
 201                 default:
 202                         diodes = "disabled";
 203                         break;
 204                 }
 205         }
 206
 207         return sprintf(buf, "%s %s\n", diodes, resistors);
 208 }
 209
 210 static DEVICE_ATTR(trickle_charger, S_IRUGO, ds1343_show_tricklecharger, NULL);
 211
 212 static int ds1343_sysfs_register(struct device *dev)
 213 {
 214         int err;
 215
 216         err = device_create_file(dev, &dev_attr_glitch_filter);
 217         if (err)
 218                 return err;
 219
 220         err = device_create_file(dev, &dev_attr_trickle_charger);
 221         if (!err)
 222                 return 0;
 223
 224         device_remove_file(dev, &dev_attr_glitch_filter);
 225
 226         return err;
 227 }
 228
 229 static void ds1343_sysfs_unregister(struct device *dev)
 230 {
 231         device_remove_file(dev, &dev_attr_glitch_filter);
 232         device_remove_file(dev, &dev_attr_trickle_charger);
 233 }
 234
 235 static int ds1343_read_time(struct device *dev, struct rtc_time *dt)
 236 {
 237         struct ds1343_priv *priv = dev_get_drvdata(dev);
 238         unsigned char buf[7];
 239         int res;
 240
 241         res = regmap_bulk_read(priv->map, DS1343_SECONDS_REG, buf, 7);
 242         if (res)
 243                 return res;
 244
 245         dt->tm_sec      = bcd2bin(buf[0]);
 246         dt->tm_min      = bcd2bin(buf[1]);
 247         dt->tm_hour     = bcd2bin(buf[2] & 0x3F);
 248         dt->tm_wday     = bcd2bin(buf[3]) - 1;
 249         dt->tm_mday     = bcd2bin(buf[4]);
 250         dt->tm_mon      = bcd2bin(buf[5] & 0x1F) - 1;
 251         dt->tm_year     = bcd2bin(buf[6]) + 100; /* year offset from 1900 */
 252
 253         return 0;
 254 }
 255
 256 static int ds1343_set_time(struct device *dev, struct rtc_time *dt)
 257 {
 258         struct ds1343_priv *priv = dev_get_drvdata(dev);
 259         int res;
 260
 261         res = regmap_write(priv->map, DS1343_SECONDS_REG,
 262                                 bin2bcd(dt->tm_sec));
 263         if (res)
 264                 return res;
 265
 266         res = regmap_write(priv->map, DS1343_MINUTES_REG,
 267                                 bin2bcd(dt->tm_min));
 268         if (res)
 269                 return res;
 270
 271         res = regmap_write(priv->map, DS1343_HOURS_REG,
 272                                 bin2bcd(dt->tm_hour) & 0x3F);
 273         if (res)
 274                 return res;
 275
 276         res = regmap_write(priv->map, DS1343_DAY_REG,
 277                                 bin2bcd(dt->tm_wday + 1));
 278         if (res)
 279                 return res;
 280
 281         res = regmap_write(priv->map, DS1343_DATE_REG,
 282                                 bin2bcd(dt->tm_mday));
 283         if (res)
 284                 return res;
 285
 286         res = regmap_write(priv->map, DS1343_MONTH_REG,
 287                                 bin2bcd(dt->tm_mon + 1));
 288         if (res)
 289                 return res;
 290
 291         dt->tm_year %= 100;
 292
 293         res = regmap_write(priv->map, DS1343_YEAR_REG,
 294                                 bin2bcd(dt->tm_year));
 295         if (res)
 296                 return res;
 297
 298         return 0;
 299 }
 300
 301 static int ds1343_update_alarm(struct device *dev)
 302 {
 303         struct ds1343_priv *priv = dev_get_drvdata(dev);
 304         unsigned int control, stat;
 305         unsigned char buf[4];
 306         int res = 0;
 307
 308         res = regmap_read(priv->map, DS1343_CONTROL_REG, &control);
 309         if (res)
 310                 return res;
 311
 312         res = regmap_read(priv->map, DS1343_STATUS_REG, &stat);
 313         if (res)
 314                 return res;
 315
 316         control &= ~(DS1343_A0IE);
 317         stat &= ~(DS1343_IRQF0);
 318
 319         res = regmap_write(priv->map, DS1343_CONTROL_REG, control);
 320         if (res)
 321                 return res;
 322
 323         res = regmap_write(priv->map, DS1343_STATUS_REG, stat);
 324         if (res)
 325                 return res;
 326
 327         buf[0] = priv->alarm_sec < 0 || (priv->irqen & RTC_UF) ?
 328                 0x80 : bin2bcd(priv->alarm_sec) & 0x7F;
 329         buf[1] = priv->alarm_min < 0 || (priv->irqen & RTC_UF) ?
 330                 0x80 : bin2bcd(priv->alarm_min) & 0x7F;
 331         buf[2] = priv->alarm_hour < 0 || (priv->irqen & RTC_UF) ?
 332                 0x80 : bin2bcd(priv->alarm_hour) & 0x3F;
 333         buf[3] = priv->alarm_mday < 0 || (priv->irqen & RTC_UF) ?
 334                 0x80 : bin2bcd(priv->alarm_mday) & 0x7F;
 335
 336         res = regmap_bulk_write(priv->map, DS1343_ALM0_SEC_REG, buf, 4);
 337         if (res)
 338                 return res;
 339
 340         if (priv->irqen) {
 341                 control |= DS1343_A0IE;
 342                 res = regmap_write(priv->map, DS1343_CONTROL_REG, control);
 343         }
 344
 345         return res;
 346 }
 347
 348 static int ds1343_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 349 {
 350         struct ds1343_priv *priv = dev_get_drvdata(dev);
 351         int res = 0;
 352         unsigned int stat;
 353
 354         if (priv->irq <= 0)
 355                 return -EINVAL;
 356
 357         mutex_lock(&priv->mutex);
 358
 359         res = regmap_read(priv->map, DS1343_STATUS_REG, &stat);
 360         if (res)
 361                 goto out;
 362
 363         alarm->enabled = !!(priv->irqen & RTC_AF);
 364         alarm->pending = !!(stat & DS1343_IRQF0);
 365
 366         alarm->time.tm_sec = priv->alarm_sec < 0 ? 0 : priv->alarm_sec;
 367         alarm->time.tm_min = priv->alarm_min < 0 ? 0 : priv->alarm_min;
 368         alarm->time.tm_hour = priv->alarm_hour < 0 ? 0 : priv->alarm_hour;
 369         alarm->time.tm_mday = priv->alarm_mday < 0 ? 0 : priv->alarm_mday;
 370
 371 out:
 372         mutex_unlock(&priv->mutex);
 373         return res;
 374 }
 375
 376 static int ds1343_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 377 {
 378         struct ds1343_priv *priv = dev_get_drvdata(dev);
 379         int res = 0;
 380
 381         if (priv->irq <= 0)
 382                 return -EINVAL;
 383
 384         mutex_lock(&priv->mutex);
 385
 386         priv->alarm_sec = alarm->time.tm_sec;
 387         priv->alarm_min = alarm->time.tm_min;
 388         priv->alarm_hour = alarm->time.tm_hour;
 389         priv->alarm_mday = alarm->time.tm_mday;
 390
 391         if (alarm->enabled)
 392                 priv->irqen |= RTC_AF;
 393
 394         res = ds1343_update_alarm(dev);
 395
 396         mutex_unlock(&priv->mutex);
 397
 398         return res;
 399 }
 400
 401 static int ds1343_alarm_irq_enable(struct device *dev, unsigned int enabled)
 402 {
 403         struct ds1343_priv *priv = dev_get_drvdata(dev);
 404         int res = 0;
 405
 406         if (priv->irq <= 0)
 407                 return -EINVAL;
 408
 409         mutex_lock(&priv->mutex);
 410
 411         if (enabled)
 412                 priv->irqen |= RTC_AF;
 413         else
 414                 priv->irqen &= ~RTC_AF;
 415
 416         res = ds1343_update_alarm(dev);
 417
 418         mutex_unlock(&priv->mutex);
 419
 420         return res;
 421 }
 422
 423 static irqreturn_t ds1343_thread(int irq, void *dev_id)
 424 {
 425         struct ds1343_priv *priv = dev_id;
 426         unsigned int stat, control;
 427         int res = 0;
 428
 429         mutex_lock(&priv->mutex);
 430
 431         res = regmap_read(priv->map, DS1343_STATUS_REG, &stat);
 432         if (res)
 433                 goto out;
 434
 435         if (stat & DS1343_IRQF0) {
 436                 stat &= ~DS1343_IRQF0;
 437                 regmap_write(priv->map, DS1343_STATUS_REG, stat);
 438
 439                 res = regmap_read(priv->map, DS1343_CONTROL_REG, &control);
 440                 if (res)
 441                         goto out;
 442
 443                 control &= ~DS1343_A0IE;
 444                 regmap_write(priv->map, DS1343_CONTROL_REG, control);
 445
 446                 rtc_update_irq(priv->rtc, 1, RTC_AF | RTC_IRQF);
 447         }
 448
 449 out:
 450         mutex_unlock(&priv->mutex);
 451         return IRQ_HANDLED;
 452 }
 453
 454 static const struct rtc_class_ops ds1343_rtc_ops = {
 455         .ioctl          = ds1343_ioctl,
 456         .read_time      = ds1343_read_time,
 457         .set_time       = ds1343_set_time,
 458         .read_alarm     = ds1343_read_alarm,
 459         .set_alarm      = ds1343_set_alarm,
 460         .alarm_irq_enable = ds1343_alarm_irq_enable,
 461 };
 462
 463 static int ds1343_probe(struct spi_device *spi)
 464 {
 465         struct ds1343_priv *priv;
 466         struct regmap_config config = { .reg_bits = 8, .val_bits = 8,
 467                                         .write_flag_mask = 0x80, };
 468         unsigned int data;
 469         int res;
 470         struct nvmem_config nvmem_cfg = {
 471                 .name = "ds1343-",
 472                 .word_size = 1,
 473                 .stride = 1,
 474                 .size = DS1343_NVRAM_LEN,
 475                 .reg_read = ds1343_nvram_read,
 476                 .reg_write = ds1343_nvram_write,
 477         };
 478
 479         priv = devm_kzalloc(&spi->dev, sizeof(struct ds1343_priv), GFP_KERNEL);
 480         if (!priv)
 481                 return -ENOMEM;
 482
 483         priv->spi = spi;
 484         mutex_init(&priv->mutex);
 485
 486         /* RTC DS1347 works in spi mode 3 and
 487          * its chip select is active high
 488          */
 489         spi->mode = SPI_MODE_3 | SPI_CS_HIGH;
 490         spi->bits_per_word = 8;
 491         res = spi_setup(spi);
 492         if (res)
 493                 return res;
 494
 495         spi_set_drvdata(spi, priv);
 496
 497         priv->map = devm_regmap_init_spi(spi, &config);
 498
 499         if (IS_ERR(priv->map)) {
 500                 dev_err(&spi->dev, "spi regmap init failed for rtc ds1343\n");
 501                 return PTR_ERR(priv->map);
 502         }
 503
 504         res = regmap_read(priv->map, DS1343_SECONDS_REG, &data);
 505         if (res)
 506                 return res;
 507
 508         regmap_read(priv->map, DS1343_CONTROL_REG, &data);
 509         data |= DS1343_INTCN;
 510         data &= ~(DS1343_EOSC | DS1343_A1IE | DS1343_A0IE);
 511         regmap_write(priv->map, DS1343_CONTROL_REG, data);
 512
 513         regmap_read(priv->map, DS1343_STATUS_REG, &data);
 514         data &= ~(DS1343_OSF | DS1343_IRQF1 | DS1343_IRQF0);
 515         regmap_write(priv->map, DS1343_STATUS_REG, data);
 516
 517         priv->rtc = devm_rtc_allocate_device(&spi->dev);
 518         if (IS_ERR(priv->rtc))
 519                 return PTR_ERR(priv->rtc);
 520
 521         priv->rtc->nvram_old_abi = true;
 522         priv->rtc->ops = &ds1343_rtc_ops;
 523
 524         res = rtc_register_device(priv->rtc);
 525         if (res)
 526                 return res;
 527
 528         nvmem_cfg.priv = priv;
 529         rtc_nvmem_register(priv->rtc, &nvmem_cfg);
 530
 531         priv->irq = spi->irq;
 532
 533         if (priv->irq >= 0) {
 534                 res = devm_request_threaded_irq(&spi->dev, spi->irq, NULL,
 535                                                 ds1343_thread, IRQF_ONESHOT,
 536                                                 "ds1343", priv);
 537                 if (res) {
 538                         priv->irq = -1;
 539                         dev_err(&spi->dev,
 540                                 "unable to request irq for rtc ds1343\n");
 541                 } else {
 542                         device_init_wakeup(&spi->dev, true);
 543                         dev_pm_set_wake_irq(&spi->dev, spi->irq);
 544                 }
 545         }
 546
 547         res = ds1343_sysfs_register(&spi->dev);
 548         if (res)
 549                 dev_err(&spi->dev,
 550                         "unable to create sysfs entries for rtc ds1343\n");
 551
 552         return 0;
 553 }
 554
 555 static int ds1343_remove(struct spi_device *spi)
 556 {
 557         struct ds1343_priv *priv = spi_get_drvdata(spi);
 558
 559         if (spi->irq) {
 560                 mutex_lock(&priv->mutex);
 561                 priv->irqen &= ~RTC_AF;
 562                 mutex_unlock(&priv->mutex);
 563
 564                 dev_pm_clear_wake_irq(&spi->dev);
 565                 device_init_wakeup(&spi->dev, false);
 566                 devm_free_irq(&spi->dev, spi->irq, priv);
 567         }
 568
 569         spi_set_drvdata(spi, NULL);
 570
 571         ds1343_sysfs_unregister(&spi->dev);
 572
 573         return 0;
 574 }
 575
 576 #ifdef CONFIG_PM_SLEEP
 577
 578 static int ds1343_suspend(struct device *dev)
 579 {
 580         struct spi_device *spi = to_spi_device(dev);
 581
 582         if (spi->irq >= 0 && device_may_wakeup(dev))
 583                 enable_irq_wake(spi->irq);
 584
 585         return 0;
 586 }
 587
 588 static int ds1343_resume(struct device *dev)
 589 {
 590         struct spi_device *spi = to_spi_device(dev);
 591
 592         if (spi->irq >= 0 && device_may_wakeup(dev))
 593                 disable_irq_wake(spi->irq);
 594
 595         return 0;
 596 }
 597
 598 #endif
 599
 600 static SIMPLE_DEV_PM_OPS(ds1343_pm, ds1343_suspend, ds1343_resume);
 601
 602 static struct spi_driver ds1343_driver = {
 603         .driver = {
 604                 .name = "ds1343",
 605                 .pm = &ds1343_pm,
 606         },
 607         .probe = ds1343_probe,
 608         .remove = ds1343_remove,
 609         .id_table = ds1343_id,
 610 };
 611
 612 module_spi_driver(ds1343_driver);
 613
 614 MODULE_DESCRIPTION("DS1343 RTC SPI Driver");
 615 MODULE_AUTHOR("Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>,"
 616                 "Ankur Srivastava <sankurece@gmail.com>");
 617 MODULE_LICENSE("GPL v2");