linux/drivers/rtc/rtc-abx80x.c
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   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
  90static u8 trickle_resistors[] = {0, 3, 6, 11};
  91
  92enum abx80x_chip {AB0801, AB0803, AB0804, AB0805,
  93        AB1801, AB1803, AB1804, AB1805, RV1805, ABX80X};
  94
  95struct abx80x_cap {
  96        u16 pn;
  97        bool has_tc;
  98        bool has_wdog;
  99};
 100
 101static 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
 114struct abx80x_priv {
 115        struct rtc_device *rtc;
 116        struct i2c_client *client;
 117        struct watchdog_device wdog;
 118};
 119
 120static 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
 134static 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
 161static 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
 201static 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
 241static 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
 267static 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
 299static 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
 333static 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
 373static 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
 392static 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
 410static 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
 425static DEVICE_ATTR_RW(autocalibration);
 426
 427static 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
 469static 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
 489static DEVICE_ATTR_RW(oscillator);
 490
 491static struct attribute *rtc_calib_attrs[] = {
 492        &dev_attr_autocalibration.attr,
 493        &dev_attr_oscillator.attr,
 494        NULL,
 495};
 496
 497static const struct attribute_group rtc_calib_attr_group = {
 498        .attrs          = rtc_calib_attrs,
 499};
 500
 501static 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
 516static 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
 549static 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
 558static 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
 597static 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
 603static 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
 616static 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
 630static int abx80x_wdog_ping(struct watchdog_device *wdog)
 631{
 632        return __abx80x_wdog_set_timeout(wdog, wdog->timeout);
 633}
 634
 635static int abx80x_wdog_start(struct watchdog_device *wdog)
 636{
 637        return __abx80x_wdog_set_timeout(wdog, wdog->timeout);
 638}
 639
 640static int abx80x_wdog_stop(struct watchdog_device *wdog)
 641{
 642        return __abx80x_wdog_set_timeout(wdog, 0);
 643}
 644
 645static const struct watchdog_info abx80x_wdog_info = {
 646        .identity = "abx80x watchdog",
 647        .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
 648};
 649
 650static 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
 658static 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
 672static int abx80x_setup_watchdog(struct abx80x_priv *priv)
 673{
 674        return 0;
 675}
 676#endif
 677
 678static 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 rtc_register_device(priv->rtc);
 855}
 856
 857static 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};
 870MODULE_DEVICE_TABLE(i2c, abx80x_id);
 871
 872#ifdef CONFIG_OF
 873static 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};
 916MODULE_DEVICE_TABLE(of, abx80x_of_match);
 917#endif
 918
 919static 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
 928module_i2c_driver(abx80x_driver);
 929
 930MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
 931MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
 932MODULE_DESCRIPTION("Abracon ABX80X RTC driver");
 933MODULE_LICENSE("GPL v2");
 934