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_write_config_key(struct i2c_client *client, u8 key)
 121{
 122        if (i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY, key) < 0) {
 123                dev_err(&client->dev, "Unable to write configuration key\n");
 124                return -EIO;
 125        }
 126
 127        return 0;
 128}
 129
 130static int abx80x_is_rc_mode(struct i2c_client *client)
 131{
 132        int flags = 0;
 133
 134        flags =  i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
 135        if (flags < 0) {
 136                dev_err(&client->dev,
 137                        "Failed to read autocalibration attribute\n");
 138                return flags;
 139        }
 140
 141        return (flags & ABX8XX_OSS_OMODE) ? 1 : 0;
 142}
 143
 144static int abx80x_enable_trickle_charger(struct i2c_client *client,
 145                                         u8 trickle_cfg)
 146{
 147        int err;
 148
 149        /*
 150         * Write the configuration key register to enable access to the Trickle
 151         * register
 152         */
 153        if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_MISC) < 0)
 154                return -EIO;
 155
 156        err = i2c_smbus_write_byte_data(client, ABX8XX_REG_TRICKLE,
 157                                        ABX8XX_TRICKLE_CHARGE_ENABLE |
 158                                        trickle_cfg);
 159        if (err < 0) {
 160                dev_err(&client->dev, "Unable to write trickle register\n");
 161                return -EIO;
 162        }
 163
 164        return 0;
 165}
 166
 167static int abx80x_rtc_read_time(struct device *dev, struct rtc_time *tm)
 168{
 169        struct i2c_client *client = to_i2c_client(dev);
 170        unsigned char buf[8];
 171        int err, flags, rc_mode = 0;
 172
 173        /* Read the Oscillator Failure only in XT mode */
 174        rc_mode = abx80x_is_rc_mode(client);
 175        if (rc_mode < 0)
 176                return rc_mode;
 177
 178        if (!rc_mode) {
 179                flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
 180                if (flags < 0)
 181                        return flags;
 182
 183                if (flags & ABX8XX_OSS_OF) {
 184                        dev_err(dev, "Oscillator failure, data is invalid.\n");
 185                        return -EINVAL;
 186                }
 187        }
 188
 189        err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_HTH,
 190                                            sizeof(buf), buf);
 191        if (err < 0) {
 192                dev_err(&client->dev, "Unable to read date\n");
 193                return -EIO;
 194        }
 195
 196        tm->tm_sec = bcd2bin(buf[ABX8XX_REG_SC] & 0x7F);
 197        tm->tm_min = bcd2bin(buf[ABX8XX_REG_MN] & 0x7F);
 198        tm->tm_hour = bcd2bin(buf[ABX8XX_REG_HR] & 0x3F);
 199        tm->tm_wday = buf[ABX8XX_REG_WD] & 0x7;
 200        tm->tm_mday = bcd2bin(buf[ABX8XX_REG_DA] & 0x3F);
 201        tm->tm_mon = bcd2bin(buf[ABX8XX_REG_MO] & 0x1F) - 1;
 202        tm->tm_year = bcd2bin(buf[ABX8XX_REG_YR]) + 100;
 203
 204        return 0;
 205}
 206
 207static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
 208{
 209        struct i2c_client *client = to_i2c_client(dev);
 210        unsigned char buf[8];
 211        int err, flags;
 212
 213        if (tm->tm_year < 100)
 214                return -EINVAL;
 215
 216        buf[ABX8XX_REG_HTH] = 0;
 217        buf[ABX8XX_REG_SC] = bin2bcd(tm->tm_sec);
 218        buf[ABX8XX_REG_MN] = bin2bcd(tm->tm_min);
 219        buf[ABX8XX_REG_HR] = bin2bcd(tm->tm_hour);
 220        buf[ABX8XX_REG_DA] = bin2bcd(tm->tm_mday);
 221        buf[ABX8XX_REG_MO] = bin2bcd(tm->tm_mon + 1);
 222        buf[ABX8XX_REG_YR] = bin2bcd(tm->tm_year - 100);
 223        buf[ABX8XX_REG_WD] = tm->tm_wday;
 224
 225        err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_HTH,
 226                                             sizeof(buf), buf);
 227        if (err < 0) {
 228                dev_err(&client->dev, "Unable to write to date registers\n");
 229                return -EIO;
 230        }
 231
 232        /* Clear the OF bit of Oscillator Status Register */
 233        flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
 234        if (flags < 0)
 235                return flags;
 236
 237        err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSS,
 238                                        flags & ~ABX8XX_OSS_OF);
 239        if (err < 0) {
 240                dev_err(&client->dev, "Unable to write oscillator status register\n");
 241                return err;
 242        }
 243
 244        return 0;
 245}
 246
 247static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
 248{
 249        struct i2c_client *client = dev_id;
 250        struct abx80x_priv *priv = i2c_get_clientdata(client);
 251        struct rtc_device *rtc = priv->rtc;
 252        int status;
 253
 254        status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
 255        if (status < 0)
 256                return IRQ_NONE;
 257
 258        if (status & ABX8XX_STATUS_AF)
 259                rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF);
 260
 261        /*
 262         * It is unclear if we'll get an interrupt before the external
 263         * reset kicks in.
 264         */
 265        if (status & ABX8XX_STATUS_WDT)
 266                dev_alert(&client->dev, "watchdog timeout interrupt.\n");
 267
 268        i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
 269
 270        return IRQ_HANDLED;
 271}
 272
 273static int abx80x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 274{
 275        struct i2c_client *client = to_i2c_client(dev);
 276        unsigned char buf[7];
 277
 278        int irq_mask, err;
 279
 280        if (client->irq <= 0)
 281                return -EINVAL;
 282
 283        err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ASC,
 284                                            sizeof(buf), buf);
 285        if (err)
 286                return err;
 287
 288        irq_mask = i2c_smbus_read_byte_data(client, ABX8XX_REG_IRQ);
 289        if (irq_mask < 0)
 290                return irq_mask;
 291
 292        t->time.tm_sec = bcd2bin(buf[0] & 0x7F);
 293        t->time.tm_min = bcd2bin(buf[1] & 0x7F);
 294        t->time.tm_hour = bcd2bin(buf[2] & 0x3F);
 295        t->time.tm_mday = bcd2bin(buf[3] & 0x3F);
 296        t->time.tm_mon = bcd2bin(buf[4] & 0x1F) - 1;
 297        t->time.tm_wday = buf[5] & 0x7;
 298
 299        t->enabled = !!(irq_mask & ABX8XX_IRQ_AIE);
 300        t->pending = (buf[6] & ABX8XX_STATUS_AF) && t->enabled;
 301
 302        return err;
 303}
 304
 305static int abx80x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 306{
 307        struct i2c_client *client = to_i2c_client(dev);
 308        u8 alarm[6];
 309        int err;
 310
 311        if (client->irq <= 0)
 312                return -EINVAL;
 313
 314        alarm[0] = 0x0;
 315        alarm[1] = bin2bcd(t->time.tm_sec);
 316        alarm[2] = bin2bcd(t->time.tm_min);
 317        alarm[3] = bin2bcd(t->time.tm_hour);
 318        alarm[4] = bin2bcd(t->time.tm_mday);
 319        alarm[5] = bin2bcd(t->time.tm_mon + 1);
 320
 321        err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_AHTH,
 322                                             sizeof(alarm), alarm);
 323        if (err < 0) {
 324                dev_err(&client->dev, "Unable to write alarm registers\n");
 325                return -EIO;
 326        }
 327
 328        if (t->enabled) {
 329                err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
 330                                                (ABX8XX_IRQ_IM_1_4 |
 331                                                 ABX8XX_IRQ_AIE));
 332                if (err)
 333                        return err;
 334        }
 335
 336        return 0;
 337}
 338
 339static int abx80x_rtc_set_autocalibration(struct device *dev,
 340                                          int autocalibration)
 341{
 342        struct i2c_client *client = to_i2c_client(dev);
 343        int retval, flags = 0;
 344
 345        if ((autocalibration != 0) && (autocalibration != 1024) &&
 346            (autocalibration != 512)) {
 347                dev_err(dev, "autocalibration value outside permitted range\n");
 348                return -EINVAL;
 349        }
 350
 351        flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
 352        if (flags < 0)
 353                return flags;
 354
 355        if (autocalibration == 0) {
 356                flags &= ~(ABX8XX_OSC_ACAL_512 | ABX8XX_OSC_ACAL_1024);
 357        } else if (autocalibration == 1024) {
 358                /* 1024 autocalibration is 0x10 */
 359                flags |= ABX8XX_OSC_ACAL_1024;
 360                flags &= ~(ABX8XX_OSC_ACAL_512);
 361        } else {
 362                /* 512 autocalibration is 0x11 */
 363                flags |= (ABX8XX_OSC_ACAL_1024 | ABX8XX_OSC_ACAL_512);
 364        }
 365
 366        /* Unlock write access to Oscillator Control Register */
 367        if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_OSC) < 0)
 368                return -EIO;
 369
 370        retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
 371
 372        return retval;
 373}
 374
 375static int abx80x_rtc_get_autocalibration(struct device *dev)
 376{
 377        struct i2c_client *client = to_i2c_client(dev);
 378        int flags = 0, autocalibration;
 379
 380        flags =  i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
 381        if (flags < 0)
 382                return flags;
 383
 384        if (flags & ABX8XX_OSC_ACAL_512)
 385                autocalibration = 512;
 386        else if (flags & ABX8XX_OSC_ACAL_1024)
 387                autocalibration = 1024;
 388        else
 389                autocalibration = 0;
 390
 391        return autocalibration;
 392}
 393
 394static ssize_t autocalibration_store(struct device *dev,
 395                                     struct device_attribute *attr,
 396                                     const char *buf, size_t count)
 397{
 398        int retval;
 399        unsigned long autocalibration = 0;
 400
 401        retval = kstrtoul(buf, 10, &autocalibration);
 402        if (retval < 0) {
 403                dev_err(dev, "Failed to store RTC autocalibration attribute\n");
 404                return -EINVAL;
 405        }
 406
 407        retval = abx80x_rtc_set_autocalibration(dev->parent, autocalibration);
 408
 409        return retval ? retval : count;
 410}
 411
 412static ssize_t autocalibration_show(struct device *dev,
 413                                    struct device_attribute *attr, char *buf)
 414{
 415        int autocalibration = 0;
 416
 417        autocalibration = abx80x_rtc_get_autocalibration(dev->parent);
 418        if (autocalibration < 0) {
 419                dev_err(dev, "Failed to read RTC autocalibration\n");
 420                sprintf(buf, "0\n");
 421                return autocalibration;
 422        }
 423
 424        return sprintf(buf, "%d\n", autocalibration);
 425}
 426
 427static DEVICE_ATTR_RW(autocalibration);
 428
 429static ssize_t oscillator_store(struct device *dev,
 430                                struct device_attribute *attr,
 431                                const char *buf, size_t count)
 432{
 433        struct i2c_client *client = to_i2c_client(dev->parent);
 434        int retval, flags, rc_mode = 0;
 435
 436        if (strncmp(buf, "rc", 2) == 0) {
 437                rc_mode = 1;
 438        } else if (strncmp(buf, "xtal", 4) == 0) {
 439                rc_mode = 0;
 440        } else {
 441                dev_err(dev, "Oscillator selection value outside permitted ones\n");
 442                return -EINVAL;
 443        }
 444
 445        flags =  i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
 446        if (flags < 0)
 447                return flags;
 448
 449        if (rc_mode == 0)
 450                flags &= ~(ABX8XX_OSC_OSEL);
 451        else
 452                flags |= (ABX8XX_OSC_OSEL);
 453
 454        /* Unlock write access on Oscillator Control register */
 455        if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_OSC) < 0)
 456                return -EIO;
 457
 458        retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
 459        if (retval < 0) {
 460                dev_err(dev, "Failed to write Oscillator Control register\n");
 461                return retval;
 462        }
 463
 464        return retval ? retval : count;
 465}
 466
 467static ssize_t oscillator_show(struct device *dev,
 468                               struct device_attribute *attr, char *buf)
 469{
 470        int rc_mode = 0;
 471        struct i2c_client *client = to_i2c_client(dev->parent);
 472
 473        rc_mode = abx80x_is_rc_mode(client);
 474
 475        if (rc_mode < 0) {
 476                dev_err(dev, "Failed to read RTC oscillator selection\n");
 477                sprintf(buf, "\n");
 478                return rc_mode;
 479        }
 480
 481        if (rc_mode)
 482                return sprintf(buf, "rc\n");
 483        else
 484                return sprintf(buf, "xtal\n");
 485}
 486
 487static DEVICE_ATTR_RW(oscillator);
 488
 489static struct attribute *rtc_calib_attrs[] = {
 490        &dev_attr_autocalibration.attr,
 491        &dev_attr_oscillator.attr,
 492        NULL,
 493};
 494
 495static const struct attribute_group rtc_calib_attr_group = {
 496        .attrs          = rtc_calib_attrs,
 497};
 498
 499static int abx80x_alarm_irq_enable(struct device *dev, unsigned int enabled)
 500{
 501        struct i2c_client *client = to_i2c_client(dev);
 502        int err;
 503
 504        if (enabled)
 505                err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
 506                                                (ABX8XX_IRQ_IM_1_4 |
 507                                                 ABX8XX_IRQ_AIE));
 508        else
 509                err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
 510                                                ABX8XX_IRQ_IM_1_4);
 511        return err;
 512}
 513
 514static int abx80x_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 515{
 516        struct i2c_client *client = to_i2c_client(dev);
 517        int status, tmp;
 518
 519        switch (cmd) {
 520        case RTC_VL_READ:
 521                status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
 522                if (status < 0)
 523                        return status;
 524
 525                tmp = status & ABX8XX_STATUS_BLF ? RTC_VL_BACKUP_LOW : 0;
 526
 527                return put_user(tmp, (unsigned int __user *)arg);
 528
 529        case RTC_VL_CLR:
 530                status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
 531                if (status < 0)
 532                        return status;
 533
 534                status &= ~ABX8XX_STATUS_BLF;
 535
 536                tmp = i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
 537                if (tmp < 0)
 538                        return tmp;
 539
 540                return 0;
 541
 542        default:
 543                return -ENOIOCTLCMD;
 544        }
 545}
 546
 547static const struct rtc_class_ops abx80x_rtc_ops = {
 548        .read_time      = abx80x_rtc_read_time,
 549        .set_time       = abx80x_rtc_set_time,
 550        .read_alarm     = abx80x_read_alarm,
 551        .set_alarm      = abx80x_set_alarm,
 552        .alarm_irq_enable = abx80x_alarm_irq_enable,
 553        .ioctl          = abx80x_ioctl,
 554};
 555
 556static int abx80x_dt_trickle_cfg(struct i2c_client *client)
 557{
 558        struct device_node *np = client->dev.of_node;
 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                dev_dbg(&client->dev, "Invalid tc-diode value: %s\n", diode);
 574                return -EINVAL;
 575        }
 576
 577        ret = of_property_read_u32(np, "abracon,tc-resistor", &tmp);
 578        if (ret)
 579                return ret;
 580
 581        for (i = 0; i < sizeof(trickle_resistors); i++)
 582                if (trickle_resistors[i] == tmp)
 583                        break;
 584
 585        if (i == sizeof(trickle_resistors)) {
 586                dev_dbg(&client->dev, "Invalid tc-resistor value: %u\n", tmp);
 587                return -EINVAL;
 588        }
 589
 590        return (trickle_cfg | i);
 591}
 592
 593#ifdef CONFIG_WATCHDOG
 594
 595static inline u8 timeout_bits(unsigned int timeout)
 596{
 597        return ((timeout << ABX8XX_WDT_BMB_SHIFT) & ABX8XX_WDT_BMB_MASK) |
 598                 ABX8XX_WDT_WRB_1HZ;
 599}
 600
 601static int __abx80x_wdog_set_timeout(struct watchdog_device *wdog,
 602                                     unsigned int timeout)
 603{
 604        struct abx80x_priv *priv = watchdog_get_drvdata(wdog);
 605        u8 val = ABX8XX_WDT_WDS | timeout_bits(timeout);
 606
 607        /*
 608         * Writing any timeout to the WDT register resets the watchdog timer.
 609         * Writing 0 disables it.
 610         */
 611        return i2c_smbus_write_byte_data(priv->client, ABX8XX_REG_WDT, val);
 612}
 613
 614static int abx80x_wdog_set_timeout(struct watchdog_device *wdog,
 615                                   unsigned int new_timeout)
 616{
 617        int err = 0;
 618
 619        if (watchdog_hw_running(wdog))
 620                err = __abx80x_wdog_set_timeout(wdog, new_timeout);
 621
 622        if (err == 0)
 623                wdog->timeout = new_timeout;
 624
 625        return err;
 626}
 627
 628static int abx80x_wdog_ping(struct watchdog_device *wdog)
 629{
 630        return __abx80x_wdog_set_timeout(wdog, wdog->timeout);
 631}
 632
 633static int abx80x_wdog_start(struct watchdog_device *wdog)
 634{
 635        return __abx80x_wdog_set_timeout(wdog, wdog->timeout);
 636}
 637
 638static int abx80x_wdog_stop(struct watchdog_device *wdog)
 639{
 640        return __abx80x_wdog_set_timeout(wdog, 0);
 641}
 642
 643static const struct watchdog_info abx80x_wdog_info = {
 644        .identity = "abx80x watchdog",
 645        .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
 646};
 647
 648static const struct watchdog_ops abx80x_wdog_ops = {
 649        .owner = THIS_MODULE,
 650        .start = abx80x_wdog_start,
 651        .stop = abx80x_wdog_stop,
 652        .ping = abx80x_wdog_ping,
 653        .set_timeout = abx80x_wdog_set_timeout,
 654};
 655
 656static int abx80x_setup_watchdog(struct abx80x_priv *priv)
 657{
 658        priv->wdog.parent = &priv->client->dev;
 659        priv->wdog.ops = &abx80x_wdog_ops;
 660        priv->wdog.info = &abx80x_wdog_info;
 661        priv->wdog.min_timeout = 1;
 662        priv->wdog.max_timeout = ABX8XX_WDT_MAX_TIME;
 663        priv->wdog.timeout = ABX8XX_WDT_MAX_TIME;
 664
 665        watchdog_set_drvdata(&priv->wdog, priv);
 666
 667        return devm_watchdog_register_device(&priv->client->dev, &priv->wdog);
 668}
 669#else
 670static int abx80x_setup_watchdog(struct abx80x_priv *priv)
 671{
 672        return 0;
 673}
 674#endif
 675
 676static int abx80x_probe(struct i2c_client *client,
 677                        const struct i2c_device_id *id)
 678{
 679        struct device_node *np = client->dev.of_node;
 680        struct abx80x_priv *priv;
 681        int i, data, err, trickle_cfg = -EINVAL;
 682        char buf[7];
 683        unsigned int part = id->driver_data;
 684        unsigned int partnumber;
 685        unsigned int majrev, minrev;
 686        unsigned int lot;
 687        unsigned int wafer;
 688        unsigned int uid;
 689
 690        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
 691                return -ENODEV;
 692
 693        err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ID0,
 694                                            sizeof(buf), buf);
 695        if (err < 0) {
 696                dev_err(&client->dev, "Unable to read partnumber\n");
 697                return -EIO;
 698        }
 699
 700        partnumber = (buf[0] << 8) | buf[1];
 701        majrev = buf[2] >> 3;
 702        minrev = buf[2] & 0x7;
 703        lot = ((buf[4] & 0x80) << 2) | ((buf[6] & 0x80) << 1) | buf[3];
 704        uid = ((buf[4] & 0x7f) << 8) | buf[5];
 705        wafer = (buf[6] & 0x7c) >> 2;
 706        dev_info(&client->dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n",
 707                 partnumber, majrev, minrev, lot, wafer, uid);
 708
 709        data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL1);
 710        if (data < 0) {
 711                dev_err(&client->dev, "Unable to read control register\n");
 712                return -EIO;
 713        }
 714
 715        err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL1,
 716                                        ((data & ~(ABX8XX_CTRL_12_24 |
 717                                                   ABX8XX_CTRL_ARST)) |
 718                                         ABX8XX_CTRL_WRITE));
 719        if (err < 0) {
 720                dev_err(&client->dev, "Unable to write control register\n");
 721                return -EIO;
 722        }
 723
 724        /* Configure RV1805 specifics */
 725        if (part == RV1805) {
 726                /*
 727                 * Avoid accidentally entering test mode. This can happen
 728                 * on the RV1805 in case the reserved bit 5 in control2
 729                 * register is set. RV-1805-C3 datasheet indicates that
 730                 * the bit should be cleared in section 11h - Control2.
 731                 */
 732                data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL2);
 733                if (data < 0) {
 734                        dev_err(&client->dev,
 735                                "Unable to read control2 register\n");
 736                        return -EIO;
 737                }
 738
 739                err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL2,
 740                                                data & ~ABX8XX_CTRL2_RSVD);
 741                if (err < 0) {
 742                        dev_err(&client->dev,
 743                                "Unable to write control2 register\n");
 744                        return -EIO;
 745                }
 746
 747                /*
 748                 * Avoid extra power leakage. The RV1805 uses smaller
 749                 * 10pin package and the EXTI input is not present.
 750                 * Disable it to avoid leakage.
 751                 */
 752                data = i2c_smbus_read_byte_data(client, ABX8XX_REG_OUT_CTRL);
 753                if (data < 0) {
 754                        dev_err(&client->dev,
 755                                "Unable to read output control register\n");
 756                        return -EIO;
 757                }
 758
 759                /*
 760                 * Write the configuration key register to enable access to
 761                 * the config2 register
 762                 */
 763                if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_MISC) < 0)
 764                        return -EIO;
 765
 766                err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OUT_CTRL,
 767                                                data | ABX8XX_OUT_CTRL_EXDS);
 768                if (err < 0) {
 769                        dev_err(&client->dev,
 770                                "Unable to write output control register\n");
 771                        return -EIO;
 772                }
 773        }
 774
 775        /* part autodetection */
 776        if (part == ABX80X) {
 777                for (i = 0; abx80x_caps[i].pn; i++)
 778                        if (partnumber == abx80x_caps[i].pn)
 779                                break;
 780                if (abx80x_caps[i].pn == 0) {
 781                        dev_err(&client->dev, "Unknown part: %04x\n",
 782                                partnumber);
 783                        return -EINVAL;
 784                }
 785                part = i;
 786        }
 787
 788        if (partnumber != abx80x_caps[part].pn) {
 789                dev_err(&client->dev, "partnumber mismatch %04x != %04x\n",
 790                        partnumber, abx80x_caps[part].pn);
 791                return -EINVAL;
 792        }
 793
 794        if (np && abx80x_caps[part].has_tc)
 795                trickle_cfg = abx80x_dt_trickle_cfg(client);
 796
 797        if (trickle_cfg > 0) {
 798                dev_info(&client->dev, "Enabling trickle charger: %02x\n",
 799                         trickle_cfg);
 800                abx80x_enable_trickle_charger(client, trickle_cfg);
 801        }
 802
 803        err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CD_TIMER_CTL,
 804                                        BIT(2));
 805        if (err)
 806                return err;
 807
 808        priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
 809        if (priv == NULL)
 810                return -ENOMEM;
 811
 812        priv->rtc = devm_rtc_allocate_device(&client->dev);
 813        if (IS_ERR(priv->rtc))
 814                return PTR_ERR(priv->rtc);
 815
 816        priv->rtc->ops = &abx80x_rtc_ops;
 817        priv->client = client;
 818
 819        i2c_set_clientdata(client, priv);
 820
 821        if (abx80x_caps[part].has_wdog) {
 822                err = abx80x_setup_watchdog(priv);
 823                if (err)
 824                        return err;
 825        }
 826
 827        if (client->irq > 0) {
 828                dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
 829                err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
 830                                                abx80x_handle_irq,
 831                                                IRQF_SHARED | IRQF_ONESHOT,
 832                                                "abx8xx",
 833                                                client);
 834                if (err) {
 835                        dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
 836                        client->irq = 0;
 837                }
 838        }
 839
 840        err = rtc_add_group(priv->rtc, &rtc_calib_attr_group);
 841        if (err) {
 842                dev_err(&client->dev, "Failed to create sysfs group: %d\n",
 843                        err);
 844                return err;
 845        }
 846
 847        return devm_rtc_register_device(priv->rtc);
 848}
 849
 850static const struct i2c_device_id abx80x_id[] = {
 851        { "abx80x", ABX80X },
 852        { "ab0801", AB0801 },
 853        { "ab0803", AB0803 },
 854        { "ab0804", AB0804 },
 855        { "ab0805", AB0805 },
 856        { "ab1801", AB1801 },
 857        { "ab1803", AB1803 },
 858        { "ab1804", AB1804 },
 859        { "ab1805", AB1805 },
 860        { "rv1805", RV1805 },
 861        { }
 862};
 863MODULE_DEVICE_TABLE(i2c, abx80x_id);
 864
 865#ifdef CONFIG_OF
 866static const struct of_device_id abx80x_of_match[] = {
 867        {
 868                .compatible = "abracon,abx80x",
 869                .data = (void *)ABX80X
 870        },
 871        {
 872                .compatible = "abracon,ab0801",
 873                .data = (void *)AB0801
 874        },
 875        {
 876                .compatible = "abracon,ab0803",
 877                .data = (void *)AB0803
 878        },
 879        {
 880                .compatible = "abracon,ab0804",
 881                .data = (void *)AB0804
 882        },
 883        {
 884                .compatible = "abracon,ab0805",
 885                .data = (void *)AB0805
 886        },
 887        {
 888                .compatible = "abracon,ab1801",
 889                .data = (void *)AB1801
 890        },
 891        {
 892                .compatible = "abracon,ab1803",
 893                .data = (void *)AB1803
 894        },
 895        {
 896                .compatible = "abracon,ab1804",
 897                .data = (void *)AB1804
 898        },
 899        {
 900                .compatible = "abracon,ab1805",
 901                .data = (void *)AB1805
 902        },
 903        {
 904                .compatible = "microcrystal,rv1805",
 905                .data = (void *)RV1805
 906        },
 907        { }
 908};
 909MODULE_DEVICE_TABLE(of, abx80x_of_match);
 910#endif
 911
 912static struct i2c_driver abx80x_driver = {
 913        .driver         = {
 914                .name   = "rtc-abx80x",
 915                .of_match_table = of_match_ptr(abx80x_of_match),
 916        },
 917        .probe          = abx80x_probe,
 918        .id_table       = abx80x_id,
 919};
 920
 921module_i2c_driver(abx80x_driver);
 922
 923MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
 924MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
 925MODULE_DESCRIPTION("Abracon ABX80X RTC driver");
 926MODULE_LICENSE("GPL v2");
 927