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