drivers/rtc/rtc-abx80x.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * A driver for the I2C members of the Abracon AB x8xx RTC family,
   4  * and compatible: AB 1805 and AB 0805
   5  *
   6  * Copyright 2014-2015 Macq S.A.
   7  *
   8  * Author: Philippe De Muyter <phdm@macqel.be>
   9  * Author: Alexandre Belloni <alexandre.belloni@bootlin.com>
  10  *
  11  */
  12
  13 #include <linux/bcd.h>
  14 #include <linux/i2c.h>
  15 #include <linux/module.h>
  16 #include <linux/of_device.h>
  17 #include <linux/rtc.h>
  18 #include <linux/watchdog.h>
  19
  20 #define ABX8XX_REG_HTH          0x00
  21 #define ABX8XX_REG_SC           0x01
  22 #define ABX8XX_REG_MN           0x02
  23 #define ABX8XX_REG_HR           0x03
  24 #define ABX8XX_REG_DA           0x04
  25 #define ABX8XX_REG_MO           0x05
  26 #define ABX8XX_REG_YR           0x06
  27 #define ABX8XX_REG_WD           0x07
  28
  29 #define ABX8XX_REG_AHTH         0x08
  30 #define ABX8XX_REG_ASC          0x09
  31 #define ABX8XX_REG_AMN          0x0a
  32 #define ABX8XX_REG_AHR          0x0b
  33 #define ABX8XX_REG_ADA          0x0c
  34 #define ABX8XX_REG_AMO          0x0d
  35 #define ABX8XX_REG_AWD          0x0e
  36
  37 #define ABX8XX_REG_STATUS       0x0f
  38 #define ABX8XX_STATUS_AF        BIT(2)
  39 #define ABX8XX_STATUS_BLF       BIT(4)
  40 #define ABX8XX_STATUS_WDT       BIT(6)
  41
  42 #define ABX8XX_REG_CTRL1        0x10
  43 #define ABX8XX_CTRL_WRITE       BIT(0)
  44 #define ABX8XX_CTRL_ARST        BIT(2)
  45 #define ABX8XX_CTRL_12_24       BIT(6)
  46
  47 #define ABX8XX_REG_CTRL2        0x11
  48 #define ABX8XX_CTRL2_RSVD       BIT(5)
  49
  50 #define ABX8XX_REG_IRQ          0x12
  51 #define ABX8XX_IRQ_AIE          BIT(2)
  52 #define ABX8XX_IRQ_IM_1_4       (0x3 << 5)
  53
  54 #define ABX8XX_REG_CD_TIMER_CTL 0x18
  55
  56 #define ABX8XX_REG_OSC          0x1c
  57 #define ABX8XX_OSC_FOS          BIT(3)
  58 #define ABX8XX_OSC_BOS          BIT(4)
  59 #define ABX8XX_OSC_ACAL_512     BIT(5)
  60 #define ABX8XX_OSC_ACAL_1024    BIT(6)
  61
  62 #define ABX8XX_OSC_OSEL         BIT(7)
  63
  64 #define ABX8XX_REG_OSS          0x1d
  65 #define ABX8XX_OSS_OF           BIT(1)
  66 #define ABX8XX_OSS_OMODE        BIT(4)
  67
  68 #define ABX8XX_REG_WDT          0x1b
  69 #define ABX8XX_WDT_WDS          BIT(7)
  70 #define ABX8XX_WDT_BMB_MASK     0x7c
  71 #define ABX8XX_WDT_BMB_SHIFT    2
  72 #define ABX8XX_WDT_MAX_TIME     (ABX8XX_WDT_BMB_MASK >> ABX8XX_WDT_BMB_SHIFT)
  73 #define ABX8XX_WDT_WRB_MASK     0x03
  74 #define ABX8XX_WDT_WRB_1HZ      0x02
  75
  76 #define ABX8XX_REG_CFG_KEY      0x1f
  77 #define ABX8XX_CFG_KEY_OSC      0xa1
  78 #define ABX8XX_CFG_KEY_MISC     0x9d
  79
  80 #define ABX8XX_REG_ID0          0x28
  81
  82 #define ABX8XX_REG_OUT_CTRL     0x30
  83 #define ABX8XX_OUT_CTRL_EXDS    BIT(4)
  84
  85 #define ABX8XX_REG_TRICKLE      0x20
  86 #define ABX8XX_TRICKLE_CHARGE_ENABLE    0xa0
  87 #define ABX8XX_TRICKLE_STANDARD_DIODE   0x8
  88 #define ABX8XX_TRICKLE_SCHOTTKY_DIODE   0x4
  89
  90 static u8 trickle_resistors[] = {0, 3, 6, 11};
  91
  92 enum abx80x_chip {AB0801, AB0803, AB0804, AB0805,
  93         AB1801, AB1803, AB1804, AB1805, RV1805, ABX80X};
  94
  95 struct abx80x_cap {
  96         u16 pn;
  97         bool has_tc;
  98         bool has_wdog;
  99 };
 100
 101 static struct abx80x_cap abx80x_caps[] = {
 102         [AB0801] = {.pn = 0x0801},
 103         [AB0803] = {.pn = 0x0803},
 104         [AB0804] = {.pn = 0x0804, .has_tc = true, .has_wdog = true},
 105         [AB0805] = {.pn = 0x0805, .has_tc = true, .has_wdog = true},
 106         [AB1801] = {.pn = 0x1801},
 107         [AB1803] = {.pn = 0x1803},
 108         [AB1804] = {.pn = 0x1804, .has_tc = true, .has_wdog = true},
 109         [AB1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true},
 110         [RV1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true},
 111         [ABX80X] = {.pn = 0}
 112 };
 113
 114 struct abx80x_priv {
 115         struct rtc_device *rtc;
 116         struct i2c_client *client;
 117         struct watchdog_device wdog;
 118 };
 119
 120 static int abx80x_is_rc_mode(struct i2c_client *client)
 121 {
 122         int flags = 0;
 123
 124         flags =  i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
 125         if (flags < 0) {
 126                 dev_err(&client->dev,
 127                         "Failed to read autocalibration attribute\n");
 128                 return flags;
 129         }
 130
 131         return (flags & ABX8XX_OSS_OMODE) ? 1 : 0;
 132 }
 133
 134 static int abx80x_enable_trickle_charger(struct i2c_client *client,
 135                                          u8 trickle_cfg)
 136 {
 137         int err;
 138
 139         /*
 140          * Write the configuration key register to enable access to the Trickle
 141          * register
 142          */
 143         err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
 144                                         ABX8XX_CFG_KEY_MISC);
 145         if (err < 0) {
 146                 dev_err(&client->dev, "Unable to write configuration key\n");
 147                 return -EIO;
 148         }
 149
 150         err = i2c_smbus_write_byte_data(client, ABX8XX_REG_TRICKLE,
 151                                         ABX8XX_TRICKLE_CHARGE_ENABLE |
 152                                         trickle_cfg);
 153         if (err < 0) {
 154                 dev_err(&client->dev, "Unable to write trickle register\n");
 155                 return -EIO;
 156         }
 157
 158         return 0;
 159 }
 160
 161 static int abx80x_rtc_read_time(struct device *dev, struct rtc_time *tm)
 162 {
 163         struct i2c_client *client = to_i2c_client(dev);
 164         unsigned char buf[8];
 165         int err, flags, rc_mode = 0;
 166
 167         /* Read the Oscillator Failure only in XT mode */
 168         rc_mode = abx80x_is_rc_mode(client);
 169         if (rc_mode < 0)
 170                 return rc_mode;
 171
 172         if (!rc_mode) {
 173                 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
 174                 if (flags < 0)
 175                         return flags;
 176
 177                 if (flags & ABX8XX_OSS_OF) {
 178                         dev_err(dev, "Oscillator failure, data is invalid.\n");
 179                         return -EINVAL;
 180                 }
 181         }
 182
 183         err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_HTH,
 184                                             sizeof(buf), buf);
 185         if (err < 0) {
 186                 dev_err(&client->dev, "Unable to read date\n");
 187                 return -EIO;
 188         }
 189
 190         tm->tm_sec = bcd2bin(buf[ABX8XX_REG_SC] & 0x7F);
 191         tm->tm_min = bcd2bin(buf[ABX8XX_REG_MN] & 0x7F);
 192         tm->tm_hour = bcd2bin(buf[ABX8XX_REG_HR] & 0x3F);
 193         tm->tm_wday = buf[ABX8XX_REG_WD] & 0x7;
 194         tm->tm_mday = bcd2bin(buf[ABX8XX_REG_DA] & 0x3F);
 195         tm->tm_mon = bcd2bin(buf[ABX8XX_REG_MO] & 0x1F) - 1;
 196         tm->tm_year = bcd2bin(buf[ABX8XX_REG_YR]) + 100;
 197
 198         return 0;
 199 }
 200
 201 static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
 202 {
 203         struct i2c_client *client = to_i2c_client(dev);
 204         unsigned char buf[8];
 205         int err, flags;
 206
 207         if (tm->tm_year < 100)
 208                 return -EINVAL;
 209
 210         buf[ABX8XX_REG_HTH] = 0;
 211         buf[ABX8XX_REG_SC] = bin2bcd(tm->tm_sec);
 212         buf[ABX8XX_REG_MN] = bin2bcd(tm->tm_min);
 213         buf[ABX8XX_REG_HR] = bin2bcd(tm->tm_hour);
 214         buf[ABX8XX_REG_DA] = bin2bcd(tm->tm_mday);
 215         buf[ABX8XX_REG_MO] = bin2bcd(tm->tm_mon + 1);
 216         buf[ABX8XX_REG_YR] = bin2bcd(tm->tm_year - 100);
 217         buf[ABX8XX_REG_WD] = tm->tm_wday;
 218
 219         err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_HTH,
 220                                              sizeof(buf), buf);
 221         if (err < 0) {
 222                 dev_err(&client->dev, "Unable to write to date registers\n");
 223                 return -EIO;
 224         }
 225
 226         /* Clear the OF bit of Oscillator Status Register */
 227         flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
 228         if (flags < 0)
 229                 return flags;
 230
 231         err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSS,
 232                                         flags & ~ABX8XX_OSS_OF);
 233         if (err < 0) {
 234                 dev_err(&client->dev, "Unable to write oscillator status register\n");
 235                 return err;
 236         }
 237
 238         return 0;
 239 }
 240
 241 static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
 242 {
 243         struct i2c_client *client = dev_id;
 244         struct abx80x_priv *priv = i2c_get_clientdata(client);
 245         struct rtc_device *rtc = priv->rtc;
 246         int status;
 247
 248         status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
 249         if (status < 0)
 250                 return IRQ_NONE;
 251
 252         if (status & ABX8XX_STATUS_AF)
 253                 rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF);
 254
 255         /*
 256          * It is unclear if we'll get an interrupt before the external
 257          * reset kicks in.
 258          */
 259         if (status & ABX8XX_STATUS_WDT)
 260                 dev_alert(&client->dev, "watchdog timeout interrupt.\n");
 261
 262         i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
 263
 264         return IRQ_HANDLED;
 265 }
 266
 267 static int abx80x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 268 {
 269         struct i2c_client *client = to_i2c_client(dev);
 270         unsigned char buf[7];
 271
 272         int irq_mask, err;
 273
 274         if (client->irq <= 0)
 275                 return -EINVAL;
 276
 277         err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ASC,
 278                                             sizeof(buf), buf);
 279         if (err)
 280                 return err;
 281
 282         irq_mask = i2c_smbus_read_byte_data(client, ABX8XX_REG_IRQ);
 283         if (irq_mask < 0)
 284                 return irq_mask;
 285
 286         t->time.tm_sec = bcd2bin(buf[0] & 0x7F);
 287         t->time.tm_min = bcd2bin(buf[1] & 0x7F);
 288         t->time.tm_hour = bcd2bin(buf[2] & 0x3F);
 289         t->time.tm_mday = bcd2bin(buf[3] & 0x3F);
 290         t->time.tm_mon = bcd2bin(buf[4] & 0x1F) - 1;
 291         t->time.tm_wday = buf[5] & 0x7;
 292
 293         t->enabled = !!(irq_mask & ABX8XX_IRQ_AIE);
 294         t->pending = (buf[6] & ABX8XX_STATUS_AF) && t->enabled;
 295
 296         return err;
 297 }
 298
 299 static int abx80x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 300 {
 301         struct i2c_client *client = to_i2c_client(dev);
 302         u8 alarm[6];
 303         int err;
 304
 305         if (client->irq <= 0)
 306                 return -EINVAL;
 307
 308         alarm[0] = 0x0;
 309         alarm[1] = bin2bcd(t->time.tm_sec);
 310         alarm[2] = bin2bcd(t->time.tm_min);
 311         alarm[3] = bin2bcd(t->time.tm_hour);
 312         alarm[4] = bin2bcd(t->time.tm_mday);
 313         alarm[5] = bin2bcd(t->time.tm_mon + 1);
 314
 315         err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_AHTH,
 316                                              sizeof(alarm), alarm);
 317         if (err < 0) {
 318                 dev_err(&client->dev, "Unable to write alarm registers\n");
 319                 return -EIO;
 320         }
 321
 322         if (t->enabled) {
 323                 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
 324                                                 (ABX8XX_IRQ_IM_1_4 |
 325                                                  ABX8XX_IRQ_AIE));
 326                 if (err)
 327                         return err;
 328         }
 329
 330         return 0;
 331 }
 332
 333 static int abx80x_rtc_set_autocalibration(struct device *dev,
 334                                           int autocalibration)
 335 {
 336         struct i2c_client *client = to_i2c_client(dev);
 337         int retval, flags = 0;
 338
 339         if ((autocalibration != 0) && (autocalibration != 1024) &&
 340             (autocalibration != 512)) {
 341                 dev_err(dev, "autocalibration value outside permitted range\n");
 342                 return -EINVAL;
 343         }
 344
 345         flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
 346         if (flags < 0)
 347                 return flags;
 348
 349         if (autocalibration == 0) {
 350                 flags &= ~(ABX8XX_OSC_ACAL_512 | ABX8XX_OSC_ACAL_1024);
 351         } else if (autocalibration == 1024) {
 352                 /* 1024 autocalibration is 0x10 */
 353                 flags |= ABX8XX_OSC_ACAL_1024;
 354                 flags &= ~(ABX8XX_OSC_ACAL_512);
 355         } else {
 356                 /* 512 autocalibration is 0x11 */
 357                 flags |= (ABX8XX_OSC_ACAL_1024 | ABX8XX_OSC_ACAL_512);
 358         }
 359
 360         /* Unlock write access to Oscillator Control Register */
 361         retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
 362                                            ABX8XX_CFG_KEY_OSC);
 363         if (retval < 0) {
 364                 dev_err(dev, "Failed to write CONFIG_KEY register\n");
 365                 return retval;
 366         }
 367
 368         retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
 369
 370         return retval;
 371 }
 372
 373 static int abx80x_rtc_get_autocalibration(struct device *dev)
 374 {
 375         struct i2c_client *client = to_i2c_client(dev);
 376         int flags = 0, autocalibration;
 377
 378         flags =  i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
 379         if (flags < 0)
 380                 return flags;
 381
 382         if (flags & ABX8XX_OSC_ACAL_512)
 383                 autocalibration = 512;
 384         else if (flags & ABX8XX_OSC_ACAL_1024)
 385                 autocalibration = 1024;
 386         else
 387                 autocalibration = 0;
 388
 389         return autocalibration;
 390 }
 391
 392 static ssize_t autocalibration_store(struct device *dev,
 393                                      struct device_attribute *attr,
 394                                      const char *buf, size_t count)
 395 {
 396         int retval;
 397         unsigned long autocalibration = 0;
 398
 399         retval = kstrtoul(buf, 10, &autocalibration);
 400         if (retval < 0) {
 401                 dev_err(dev, "Failed to store RTC autocalibration attribute\n");
 402                 return -EINVAL;
 403         }
 404
 405         retval = abx80x_rtc_set_autocalibration(dev->parent, autocalibration);
 406
 407         return retval ? retval : count;
 408 }
 409
 410 static ssize_t autocalibration_show(struct device *dev,
 411                                     struct device_attribute *attr, char *buf)
 412 {
 413         int autocalibration = 0;
 414
 415         autocalibration = abx80x_rtc_get_autocalibration(dev->parent);
 416         if (autocalibration < 0) {
 417                 dev_err(dev, "Failed to read RTC autocalibration\n");
 418                 sprintf(buf, "0\n");
 419                 return autocalibration;
 420         }
 421
 422         return sprintf(buf, "%d\n", autocalibration);
 423 }
 424
 425 static DEVICE_ATTR_RW(autocalibration);
 426
 427 static ssize_t oscillator_store(struct device *dev,
 428                                 struct device_attribute *attr,
 429                                 const char *buf, size_t count)
 430 {
 431         struct i2c_client *client = to_i2c_client(dev->parent);
 432         int retval, flags, rc_mode = 0;
 433
 434         if (strncmp(buf, "rc", 2) == 0) {
 435                 rc_mode = 1;
 436         } else if (strncmp(buf, "xtal", 4) == 0) {
 437                 rc_mode = 0;
 438         } else {
 439                 dev_err(dev, "Oscillator selection value outside permitted ones\n");
 440                 return -EINVAL;
 441         }
 442
 443         flags =  i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
 444         if (flags < 0)
 445                 return flags;
 446
 447         if (rc_mode == 0)
 448                 flags &= ~(ABX8XX_OSC_OSEL);
 449         else
 450                 flags |= (ABX8XX_OSC_OSEL);
 451
 452         /* Unlock write access on Oscillator Control register */
 453         retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
 454                                            ABX8XX_CFG_KEY_OSC);
 455         if (retval < 0) {
 456                 dev_err(dev, "Failed to write CONFIG_KEY register\n");
 457                 return retval;
 458         }
 459
 460         retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
 461         if (retval < 0) {
 462                 dev_err(dev, "Failed to write Oscillator Control register\n");
 463                 return retval;
 464         }
 465
 466         return retval ? retval : count;
 467 }
 468
 469 static ssize_t oscillator_show(struct device *dev,
 470                                struct device_attribute *attr, char *buf)
 471 {
 472         int rc_mode = 0;
 473         struct i2c_client *client = to_i2c_client(dev->parent);
 474
 475         rc_mode = abx80x_is_rc_mode(client);
 476
 477         if (rc_mode < 0) {
 478                 dev_err(dev, "Failed to read RTC oscillator selection\n");
 479                 sprintf(buf, "\n");
 480                 return rc_mode;
 481         }
 482
 483         if (rc_mode)
 484                 return sprintf(buf, "rc\n");
 485         else
 486                 return sprintf(buf, "xtal\n");
 487 }
 488
 489 static DEVICE_ATTR_RW(oscillator);
 490
 491 static struct attribute *rtc_calib_attrs[] = {
 492         &dev_attr_autocalibration.attr,
 493         &dev_attr_oscillator.attr,
 494         NULL,
 495 };
 496
 497 static const struct attribute_group rtc_calib_attr_group = {
 498         .attrs          = rtc_calib_attrs,
 499 };
 500
 501 static int abx80x_alarm_irq_enable(struct device *dev, unsigned int enabled)
 502 {
 503         struct i2c_client *client = to_i2c_client(dev);
 504         int err;
 505
 506         if (enabled)
 507                 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
 508                                                 (ABX8XX_IRQ_IM_1_4 |
 509                                                  ABX8XX_IRQ_AIE));
 510         else
 511                 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
 512                                                 ABX8XX_IRQ_IM_1_4);
 513         return err;
 514 }
 515
 516 static int abx80x_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 517 {
 518         struct i2c_client *client = to_i2c_client(dev);
 519         int status, tmp;
 520
 521         switch (cmd) {
 522         case RTC_VL_READ:
 523                 status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
 524                 if (status < 0)
 525                         return status;
 526
 527                 tmp = status & ABX8XX_STATUS_BLF ? RTC_VL_BACKUP_LOW : 0;
 528
 529                 return put_user(tmp, (unsigned int __user *)arg);
 530
 531         case RTC_VL_CLR:
 532                 status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
 533                 if (status < 0)
 534                         return status;
 535
 536                 status &= ~ABX8XX_STATUS_BLF;
 537
 538                 tmp = i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
 539                 if (tmp < 0)
 540                         return tmp;
 541
 542                 return 0;
 543
 544         default:
 545                 return -ENOIOCTLCMD;
 546         }
 547 }
 548
 549 static const struct rtc_class_ops abx80x_rtc_ops = {
 550         .read_time      = abx80x_rtc_read_time,
 551         .set_time       = abx80x_rtc_set_time,
 552         .read_alarm     = abx80x_read_alarm,
 553         .set_alarm      = abx80x_set_alarm,
 554         .alarm_irq_enable = abx80x_alarm_irq_enable,
 555         .ioctl          = abx80x_ioctl,
 556 };
 557
 558 static int abx80x_dt_trickle_cfg(struct i2c_client *client)
 559 {
 560         struct device_node *np = client->dev.of_node;
 561         const char *diode;
 562         int trickle_cfg = 0;
 563         int i, ret;
 564         u32 tmp;
 565
 566         ret = of_property_read_string(np, "abracon,tc-diode", &diode);
 567         if (ret)
 568                 return ret;
 569
 570         if (!strcmp(diode, "standard")) {
 571                 trickle_cfg |= ABX8XX_TRICKLE_STANDARD_DIODE;
 572         } else if (!strcmp(diode, "schottky")) {
 573                 trickle_cfg |= ABX8XX_TRICKLE_SCHOTTKY_DIODE;
 574         } else {
 575                 dev_dbg(&client->dev, "Invalid tc-diode value: %s\n", diode);
 576                 return -EINVAL;
 577         }
 578
 579         ret = of_property_read_u32(np, "abracon,tc-resistor", &tmp);
 580         if (ret)
 581                 return ret;
 582
 583         for (i = 0; i < sizeof(trickle_resistors); i++)
 584                 if (trickle_resistors[i] == tmp)
 585                         break;
 586
 587         if (i == sizeof(trickle_resistors)) {
 588                 dev_dbg(&client->dev, "Invalid tc-resistor value: %u\n", tmp);
 589                 return -EINVAL;
 590         }
 591
 592         return (trickle_cfg | i);
 593 }
 594
 595 #ifdef CONFIG_WATCHDOG
 596
 597 static inline u8 timeout_bits(unsigned int timeout)
 598 {
 599         return ((timeout << ABX8XX_WDT_BMB_SHIFT) & ABX8XX_WDT_BMB_MASK) |
 600                  ABX8XX_WDT_WRB_1HZ;
 601 }
 602
 603 static int __abx80x_wdog_set_timeout(struct watchdog_device *wdog,
 604                                      unsigned int timeout)
 605 {
 606         struct abx80x_priv *priv = watchdog_get_drvdata(wdog);
 607         u8 val = ABX8XX_WDT_WDS | timeout_bits(timeout);
 608
 609         /*
 610          * Writing any timeout to the WDT register resets the watchdog timer.
 611          * Writing 0 disables it.
 612          */
 613         return i2c_smbus_write_byte_data(priv->client, ABX8XX_REG_WDT, val);
 614 }
 615
 616 static int abx80x_wdog_set_timeout(struct watchdog_device *wdog,
 617                                    unsigned int new_timeout)
 618 {
 619         int err = 0;
 620
 621         if (watchdog_hw_running(wdog))
 622                 err = __abx80x_wdog_set_timeout(wdog, new_timeout);
 623
 624         if (err == 0)
 625                 wdog->timeout = new_timeout;
 626
 627         return err;
 628 }
 629
 630 static int abx80x_wdog_ping(struct watchdog_device *wdog)
 631 {
 632         return __abx80x_wdog_set_timeout(wdog, wdog->timeout);
 633 }
 634
 635 static int abx80x_wdog_start(struct watchdog_device *wdog)
 636 {
 637         return __abx80x_wdog_set_timeout(wdog, wdog->timeout);
 638 }
 639
 640 static int abx80x_wdog_stop(struct watchdog_device *wdog)
 641 {
 642         return __abx80x_wdog_set_timeout(wdog, 0);
 643 }
 644
 645 static const struct watchdog_info abx80x_wdog_info = {
 646         .identity = "abx80x watchdog",
 647         .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
 648 };
 649
 650 static const struct watchdog_ops abx80x_wdog_ops = {
 651         .owner = THIS_MODULE,
 652         .start = abx80x_wdog_start,
 653         .stop = abx80x_wdog_stop,
 654         .ping = abx80x_wdog_ping,
 655         .set_timeout = abx80x_wdog_set_timeout,
 656 };
 657
 658 static int abx80x_setup_watchdog(struct abx80x_priv *priv)
 659 {
 660         priv->wdog.parent = &priv->client->dev;
 661         priv->wdog.ops = &abx80x_wdog_ops;
 662         priv->wdog.info = &abx80x_wdog_info;
 663         priv->wdog.min_timeout = 1;
 664         priv->wdog.max_timeout = ABX8XX_WDT_MAX_TIME;
 665         priv->wdog.timeout = ABX8XX_WDT_MAX_TIME;
 666
 667         watchdog_set_drvdata(&priv->wdog, priv);
 668
 669         return devm_watchdog_register_device(&priv->client->dev, &priv->wdog);
 670 }
 671 #else
 672 static int abx80x_setup_watchdog(struct abx80x_priv *priv)
 673 {
 674         return 0;
 675 }
 676 #endif
 677
 678 static int abx80x_probe(struct i2c_client *client,
 679                         const struct i2c_device_id *id)
 680 {
 681         struct device_node *np = client->dev.of_node;
 682         struct abx80x_priv *priv;
 683         int i, data, err, trickle_cfg = -EINVAL;
 684         char buf[7];
 685         unsigned int part = id->driver_data;
 686         unsigned int partnumber;
 687         unsigned int majrev, minrev;
 688         unsigned int lot;
 689         unsigned int wafer;
 690         unsigned int uid;
 691
 692         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
 693                 return -ENODEV;
 694
 695         err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ID0,
 696                                             sizeof(buf), buf);
 697         if (err < 0) {
 698                 dev_err(&client->dev, "Unable to read partnumber\n");
 699                 return -EIO;
 700         }
 701
 702         partnumber = (buf[0] << 8) | buf[1];
 703         majrev = buf[2] >> 3;
 704         minrev = buf[2] & 0x7;
 705         lot = ((buf[4] & 0x80) << 2) | ((buf[6] & 0x80) << 1) | buf[3];
 706         uid = ((buf[4] & 0x7f) << 8) | buf[5];
 707         wafer = (buf[6] & 0x7c) >> 2;
 708         dev_info(&client->dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n",
 709                  partnumber, majrev, minrev, lot, wafer, uid);
 710
 711         data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL1);
 712         if (data < 0) {
 713                 dev_err(&client->dev, "Unable to read control register\n");
 714                 return -EIO;
 715         }
 716
 717         err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL1,
 718                                         ((data & ~(ABX8XX_CTRL_12_24 |
 719                                                    ABX8XX_CTRL_ARST)) |
 720                                          ABX8XX_CTRL_WRITE));
 721         if (err < 0) {
 722                 dev_err(&client->dev, "Unable to write control register\n");
 723                 return -EIO;
 724         }
 725
 726         /* Configure RV1805 specifics */
 727         if (part == RV1805) {
 728                 /*
 729                  * Avoid accidentally entering test mode. This can happen
 730                  * on the RV1805 in case the reserved bit 5 in control2
 731                  * register is set. RV-1805-C3 datasheet indicates that
 732                  * the bit should be cleared in section 11h - Control2.
 733                  */
 734                 data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL2);
 735                 if (data < 0) {
 736                         dev_err(&client->dev,
 737                                 "Unable to read control2 register\n");
 738                         return -EIO;
 739                 }
 740
 741                 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL2,
 742                                                 data & ~ABX8XX_CTRL2_RSVD);
 743                 if (err < 0) {
 744                         dev_err(&client->dev,
 745                                 "Unable to write control2 register\n");
 746                         return -EIO;
 747                 }
 748
 749                 /*
 750                  * Avoid extra power leakage. The RV1805 uses smaller
 751                  * 10pin package and the EXTI input is not present.
 752                  * Disable it to avoid leakage.
 753                  */
 754                 data = i2c_smbus_read_byte_data(client, ABX8XX_REG_OUT_CTRL);
 755                 if (data < 0) {
 756                         dev_err(&client->dev,
 757                                 "Unable to read output control register\n");
 758                         return -EIO;
 759                 }
 760
 761                 /*
 762                  * Write the configuration key register to enable access to
 763                  * the config2 register
 764                  */
 765                 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
 766                                                 ABX8XX_CFG_KEY_MISC);
 767                 if (err < 0) {
 768                         dev_err(&client->dev,
 769                                 "Unable to write configuration key\n");
 770                         return -EIO;
 771                 }
 772
 773                 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OUT_CTRL,
 774                                                 data | ABX8XX_OUT_CTRL_EXDS);
 775                 if (err < 0) {
 776                         dev_err(&client->dev,
 777                                 "Unable to write output control register\n");
 778                         return -EIO;
 779                 }
 780         }
 781
 782         /* part autodetection */
 783         if (part == ABX80X) {
 784                 for (i = 0; abx80x_caps[i].pn; i++)
 785                         if (partnumber == abx80x_caps[i].pn)
 786                                 break;
 787                 if (abx80x_caps[i].pn == 0) {
 788                         dev_err(&client->dev, "Unknown part: %04x\n",
 789                                 partnumber);
 790                         return -EINVAL;
 791                 }
 792                 part = i;
 793         }
 794
 795         if (partnumber != abx80x_caps[part].pn) {
 796                 dev_err(&client->dev, "partnumber mismatch %04x != %04x\n",
 797                         partnumber, abx80x_caps[part].pn);
 798                 return -EINVAL;
 799         }
 800
 801         if (np && abx80x_caps[part].has_tc)
 802                 trickle_cfg = abx80x_dt_trickle_cfg(client);
 803
 804         if (trickle_cfg > 0) {
 805                 dev_info(&client->dev, "Enabling trickle charger: %02x\n",
 806                          trickle_cfg);
 807                 abx80x_enable_trickle_charger(client, trickle_cfg);
 808         }
 809
 810         err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CD_TIMER_CTL,
 811                                         BIT(2));
 812         if (err)
 813                 return err;
 814
 815         priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
 816         if (priv == NULL)
 817                 return -ENOMEM;
 818
 819         priv->rtc = devm_rtc_allocate_device(&client->dev);
 820         if (IS_ERR(priv->rtc))
 821                 return PTR_ERR(priv->rtc);
 822
 823         priv->rtc->ops = &abx80x_rtc_ops;
 824         priv->client = client;
 825
 826         i2c_set_clientdata(client, priv);
 827
 828         if (abx80x_caps[part].has_wdog) {
 829                 err = abx80x_setup_watchdog(priv);
 830                 if (err)
 831                         return err;
 832         }
 833
 834         if (client->irq > 0) {
 835                 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
 836                 err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
 837                                                 abx80x_handle_irq,
 838                                                 IRQF_SHARED | IRQF_ONESHOT,
 839                                                 "abx8xx",
 840                                                 client);
 841                 if (err) {
 842                         dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
 843                         client->irq = 0;
 844                 }
 845         }
 846
 847         err = rtc_add_group(priv->rtc, &rtc_calib_attr_group);
 848         if (err) {
 849                 dev_err(&client->dev, "Failed to create sysfs group: %d\n",
 850                         err);
 851                 return err;
 852         }
 853
 854         return devm_rtc_register_device(priv->rtc);
 855 }
 856
 857 static const struct i2c_device_id abx80x_id[] = {
 858         { "abx80x", ABX80X },
 859         { "ab0801", AB0801 },
 860         { "ab0803", AB0803 },
 861         { "ab0804", AB0804 },
 862         { "ab0805", AB0805 },
 863         { "ab1801", AB1801 },
 864         { "ab1803", AB1803 },
 865         { "ab1804", AB1804 },
 866         { "ab1805", AB1805 },
 867         { "rv1805", RV1805 },
 868         { }
 869 };
 870 MODULE_DEVICE_TABLE(i2c, abx80x_id);
 871
 872 #ifdef CONFIG_OF
 873 static const struct of_device_id abx80x_of_match[] = {
 874         {
 875                 .compatible = "abracon,abx80x",
 876                 .data = (void *)ABX80X
 877         },
 878         {
 879                 .compatible = "abracon,ab0801",
 880                 .data = (void *)AB0801
 881         },
 882         {
 883                 .compatible = "abracon,ab0803",
 884                 .data = (void *)AB0803
 885         },
 886         {
 887                 .compatible = "abracon,ab0804",
 888                 .data = (void *)AB0804
 889         },
 890         {
 891                 .compatible = "abracon,ab0805",
 892                 .data = (void *)AB0805
 893         },
 894         {
 895                 .compatible = "abracon,ab1801",
 896                 .data = (void *)AB1801
 897         },
 898         {
 899                 .compatible = "abracon,ab1803",
 900                 .data = (void *)AB1803
 901         },
 902         {
 903                 .compatible = "abracon,ab1804",
 904                 .data = (void *)AB1804
 905         },
 906         {
 907                 .compatible = "abracon,ab1805",
 908                 .data = (void *)AB1805
 909         },
 910         {
 911                 .compatible = "microcrystal,rv1805",
 912                 .data = (void *)RV1805
 913         },
 914         { }
 915 };
 916 MODULE_DEVICE_TABLE(of, abx80x_of_match);
 917 #endif
 918
 919 static struct i2c_driver abx80x_driver = {
 920         .driver         = {
 921                 .name   = "rtc-abx80x",
 922                 .of_match_table = of_match_ptr(abx80x_of_match),
 923         },
 924         .probe          = abx80x_probe,
 925         .id_table       = abx80x_id,
 926 };
 927
 928 module_i2c_driver(abx80x_driver);
 929
 930 MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
 931 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
 932 MODULE_DESCRIPTION("Abracon ABX80X RTC driver");
 933 MODULE_LICENSE("GPL v2");