drivers/mfd/max14577.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 //
   3 // max14577.c - mfd core driver for the Maxim 14577/77836
   4 //
   5 // Copyright (C) 2014 Samsung Electronics
   6 // Chanwoo Choi <cw00.choi@samsung.com>
   7 // Krzysztof Kozlowski <krzk@kernel.org>
   8 //
   9 // This driver is based on max8997.c
  10
  11 #include <linux/err.h>
  12 #include <linux/module.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/of_device.h>
  15 #include <linux/mfd/core.h>
  16 #include <linux/mfd/max14577.h>
  17 #include <linux/mfd/max14577-private.h>
  18
  19 /*
  20  * Table of valid charger currents for different Maxim chipsets.
  21  * It is placed here because it is used by both charger and regulator driver.
  22  */
  23 const struct maxim_charger_current maxim_charger_currents[] = {
  24         [MAXIM_DEVICE_TYPE_UNKNOWN] = { 0, 0, 0, 0 },
  25         [MAXIM_DEVICE_TYPE_MAX14577] = {
  26                 .min            = MAX14577_CHARGER_CURRENT_LIMIT_MIN,
  27                 .high_start     = MAX14577_CHARGER_CURRENT_LIMIT_HIGH_START,
  28                 .high_step      = MAX14577_CHARGER_CURRENT_LIMIT_HIGH_STEP,
  29                 .max            = MAX14577_CHARGER_CURRENT_LIMIT_MAX,
  30         },
  31         [MAXIM_DEVICE_TYPE_MAX77836] = {
  32                 .min            = MAX77836_CHARGER_CURRENT_LIMIT_MIN,
  33                 .high_start     = MAX77836_CHARGER_CURRENT_LIMIT_HIGH_START,
  34                 .high_step      = MAX77836_CHARGER_CURRENT_LIMIT_HIGH_STEP,
  35                 .max            = MAX77836_CHARGER_CURRENT_LIMIT_MAX,
  36         },
  37 };
  38 EXPORT_SYMBOL_GPL(maxim_charger_currents);
  39
  40 /*
  41  * maxim_charger_calc_reg_current - Calculate register value for current
  42  * @limits:     constraints for charger, matching the MBCICHWRC register
  43  * @min_ua:     minimal requested current, micro Amps
  44  * @max_ua:     maximum requested current, micro Amps
  45  * @dst:        destination to store calculated register value
  46  *
  47  * Calculates the value of MBCICHWRC (Fast Battery Charge Current) register
  48  * for given current and stores it under pointed 'dst'. The stored value
  49  * combines low bit (MBCICHWRCL) and high bits (MBCICHWRCH). It is also
  50  * properly shifted.
  51  *
  52  * The calculated register value matches the current which:
  53  *  - is always between <limits.min, limits.max>;
  54  *  - is always less or equal to max_ua;
  55  *  - is the highest possible value;
  56  *  - may be lower than min_ua.
  57  *
  58  * On success returns 0. On error returns -EINVAL (requested min/max current
  59  * is outside of given charger limits) and 'dst' is not set.
  60  */
  61 int maxim_charger_calc_reg_current(const struct maxim_charger_current *limits,
  62                 unsigned int min_ua, unsigned int max_ua, u8 *dst)
  63 {
  64         unsigned int current_bits;
  65
  66         if (min_ua > max_ua)
  67                 return -EINVAL;
  68
  69         if (min_ua > limits->max || max_ua < limits->min)
  70                 return -EINVAL;
  71
  72         if (max_ua < limits->high_start) {
  73                 /*
  74                  * Less than high_start, so set the minimal current
  75                  * (turn Low Bit off, 0 as high bits).
  76                  */
  77                 *dst = 0x0;
  78                 return 0;
  79         }
  80
  81         /* max_ua is in range: <high_start, infinite>, cut it to limits.max */
  82         max_ua = min(limits->max, max_ua);
  83         max_ua -= limits->high_start;
  84         /*
  85          * There is no risk of overflow 'max_ua' here because:
  86          *  - max_ua >= limits.high_start
  87          *  - BUILD_BUG checks that 'limits' are: max >= high_start + high_step
  88          */
  89         current_bits = max_ua / limits->high_step;
  90
  91         /* Turn Low Bit on (use range <limits.high_start, limits.max>) ... */
  92         *dst = 0x1 << CHGCTRL4_MBCICHWRCL_SHIFT;
  93         /* and set proper High Bits */
  94         *dst |= current_bits << CHGCTRL4_MBCICHWRCH_SHIFT;
  95
  96         return 0;
  97 }
  98 EXPORT_SYMBOL_GPL(maxim_charger_calc_reg_current);
  99
 100 static const struct mfd_cell max14577_devs[] = {
 101         {
 102                 .name = "max14577-muic",
 103                 .of_compatible = "maxim,max14577-muic",
 104         },
 105         {
 106                 .name = "max14577-regulator",
 107                 .of_compatible = "maxim,max14577-regulator",
 108         },
 109         {
 110                 .name = "max14577-charger",
 111                 .of_compatible = "maxim,max14577-charger",
 112         },
 113 };
 114
 115 static const struct mfd_cell max77836_devs[] = {
 116         {
 117                 .name = "max77836-muic",
 118                 .of_compatible = "maxim,max77836-muic",
 119         },
 120         {
 121                 .name = "max77836-regulator",
 122                 .of_compatible = "maxim,max77836-regulator",
 123         },
 124         {
 125                 .name = "max77836-charger",
 126                 .of_compatible = "maxim,max77836-charger",
 127         },
 128         {
 129                 .name = "max77836-battery",
 130                 .of_compatible = "maxim,max77836-battery",
 131         },
 132 };
 133
 134 static const struct of_device_id max14577_dt_match[] = {
 135         {
 136                 .compatible = "maxim,max14577",
 137                 .data = (void *)MAXIM_DEVICE_TYPE_MAX14577,
 138         },
 139         {
 140                 .compatible = "maxim,max77836",
 141                 .data = (void *)MAXIM_DEVICE_TYPE_MAX77836,
 142         },
 143         {},
 144 };
 145
 146 static bool max14577_muic_volatile_reg(struct device *dev, unsigned int reg)
 147 {
 148         switch (reg) {
 149         case MAX14577_REG_INT1 ... MAX14577_REG_STATUS3:
 150                 return true;
 151         default:
 152                 break;
 153         }
 154         return false;
 155 }
 156
 157 static bool max77836_muic_volatile_reg(struct device *dev, unsigned int reg)
 158 {
 159         /* Any max14577 volatile registers are also max77836 volatile. */
 160         if (max14577_muic_volatile_reg(dev, reg))
 161                 return true;
 162
 163         switch (reg) {
 164         case MAX77836_FG_REG_VCELL_MSB ... MAX77836_FG_REG_SOC_LSB:
 165         case MAX77836_FG_REG_CRATE_MSB ... MAX77836_FG_REG_CRATE_LSB:
 166         case MAX77836_FG_REG_STATUS_H ... MAX77836_FG_REG_STATUS_L:
 167         case MAX77836_PMIC_REG_INTSRC:
 168         case MAX77836_PMIC_REG_TOPSYS_INT:
 169         case MAX77836_PMIC_REG_TOPSYS_STAT:
 170                 return true;
 171         default:
 172                 break;
 173         }
 174         return false;
 175 }
 176
 177 static const struct regmap_config max14577_muic_regmap_config = {
 178         .reg_bits       = 8,
 179         .val_bits       = 8,
 180         .volatile_reg   = max14577_muic_volatile_reg,
 181         .max_register   = MAX14577_REG_END,
 182 };
 183
 184 static const struct regmap_config max77836_pmic_regmap_config = {
 185         .reg_bits       = 8,
 186         .val_bits       = 8,
 187         .volatile_reg   = max77836_muic_volatile_reg,
 188         .max_register   = MAX77836_PMIC_REG_END,
 189 };
 190
 191 static const struct regmap_irq max14577_irqs[] = {
 192         /* INT1 interrupts */
 193         { .reg_offset = 0, .mask = MAX14577_INT1_ADC_MASK, },
 194         { .reg_offset = 0, .mask = MAX14577_INT1_ADCLOW_MASK, },
 195         { .reg_offset = 0, .mask = MAX14577_INT1_ADCERR_MASK, },
 196         /* INT2 interrupts */
 197         { .reg_offset = 1, .mask = MAX14577_INT2_CHGTYP_MASK, },
 198         { .reg_offset = 1, .mask = MAX14577_INT2_CHGDETRUN_MASK, },
 199         { .reg_offset = 1, .mask = MAX14577_INT2_DCDTMR_MASK, },
 200         { .reg_offset = 1, .mask = MAX14577_INT2_DBCHG_MASK, },
 201         { .reg_offset = 1, .mask = MAX14577_INT2_VBVOLT_MASK, },
 202         /* INT3 interrupts */
 203         { .reg_offset = 2, .mask = MAX14577_INT3_EOC_MASK, },
 204         { .reg_offset = 2, .mask = MAX14577_INT3_CGMBC_MASK, },
 205         { .reg_offset = 2, .mask = MAX14577_INT3_OVP_MASK, },
 206         { .reg_offset = 2, .mask = MAX14577_INT3_MBCCHGERR_MASK, },
 207 };
 208
 209 static const struct regmap_irq_chip max14577_irq_chip = {
 210         .name                   = "max14577",
 211         .status_base            = MAX14577_REG_INT1,
 212         .mask_base              = MAX14577_REG_INTMASK1,
 213         .mask_invert            = true,
 214         .num_regs               = 3,
 215         .irqs                   = max14577_irqs,
 216         .num_irqs               = ARRAY_SIZE(max14577_irqs),
 217 };
 218
 219 static const struct regmap_irq max77836_muic_irqs[] = {
 220         /* INT1 interrupts */
 221         { .reg_offset = 0, .mask = MAX14577_INT1_ADC_MASK, },
 222         { .reg_offset = 0, .mask = MAX14577_INT1_ADCLOW_MASK, },
 223         { .reg_offset = 0, .mask = MAX14577_INT1_ADCERR_MASK, },
 224         { .reg_offset = 0, .mask = MAX77836_INT1_ADC1K_MASK, },
 225         /* INT2 interrupts */
 226         { .reg_offset = 1, .mask = MAX14577_INT2_CHGTYP_MASK, },
 227         { .reg_offset = 1, .mask = MAX14577_INT2_CHGDETRUN_MASK, },
 228         { .reg_offset = 1, .mask = MAX14577_INT2_DCDTMR_MASK, },
 229         { .reg_offset = 1, .mask = MAX14577_INT2_DBCHG_MASK, },
 230         { .reg_offset = 1, .mask = MAX14577_INT2_VBVOLT_MASK, },
 231         { .reg_offset = 1, .mask = MAX77836_INT2_VIDRM_MASK, },
 232         /* INT3 interrupts */
 233         { .reg_offset = 2, .mask = MAX14577_INT3_EOC_MASK, },
 234         { .reg_offset = 2, .mask = MAX14577_INT3_CGMBC_MASK, },
 235         { .reg_offset = 2, .mask = MAX14577_INT3_OVP_MASK, },
 236         { .reg_offset = 2, .mask = MAX14577_INT3_MBCCHGERR_MASK, },
 237 };
 238
 239 static const struct regmap_irq_chip max77836_muic_irq_chip = {
 240         .name                   = "max77836-muic",
 241         .status_base            = MAX14577_REG_INT1,
 242         .mask_base              = MAX14577_REG_INTMASK1,
 243         .mask_invert            = true,
 244         .num_regs               = 3,
 245         .irqs                   = max77836_muic_irqs,
 246         .num_irqs               = ARRAY_SIZE(max77836_muic_irqs),
 247 };
 248
 249 static const struct regmap_irq max77836_pmic_irqs[] = {
 250         { .reg_offset = 0, .mask = MAX77836_TOPSYS_INT_T120C_MASK, },
 251         { .reg_offset = 0, .mask = MAX77836_TOPSYS_INT_T140C_MASK, },
 252 };
 253
 254 static const struct regmap_irq_chip max77836_pmic_irq_chip = {
 255         .name                   = "max77836-pmic",
 256         .status_base            = MAX77836_PMIC_REG_TOPSYS_INT,
 257         .mask_base              = MAX77836_PMIC_REG_TOPSYS_INT_MASK,
 258         .mask_invert            = false,
 259         .num_regs               = 1,
 260         .irqs                   = max77836_pmic_irqs,
 261         .num_irqs               = ARRAY_SIZE(max77836_pmic_irqs),
 262 };
 263
 264 static void max14577_print_dev_type(struct max14577 *max14577)
 265 {
 266         u8 reg_data, vendor_id, device_id;
 267         int ret;
 268
 269         ret = max14577_read_reg(max14577->regmap, MAX14577_REG_DEVICEID,
 270                         &reg_data);
 271         if (ret) {
 272                 dev_err(max14577->dev,
 273                         "Failed to read DEVICEID register: %d\n", ret);
 274                 return;
 275         }
 276
 277         vendor_id = ((reg_data & DEVID_VENDORID_MASK) >>
 278                                 DEVID_VENDORID_SHIFT);
 279         device_id = ((reg_data & DEVID_DEVICEID_MASK) >>
 280                                 DEVID_DEVICEID_SHIFT);
 281
 282         dev_info(max14577->dev, "Device type: %u (ID: 0x%x, vendor: 0x%x)\n",
 283                         max14577->dev_type, device_id, vendor_id);
 284 }
 285
 286 /*
 287  * Max77836 specific initialization code for driver probe.
 288  * Adds new I2C dummy device, regmap and regmap IRQ chip.
 289  * Unmasks Interrupt Source register.
 290  *
 291  * On success returns 0.
 292  * On failure returns errno and reverts any changes done so far (e.g. remove
 293  * I2C dummy device), except masking the INT SRC register.
 294  */
 295 static int max77836_init(struct max14577 *max14577)
 296 {
 297         int ret;
 298         u8 intsrc_mask;
 299
 300         max14577->i2c_pmic = i2c_new_dummy_device(max14577->i2c->adapter,
 301                         I2C_ADDR_PMIC);
 302         if (IS_ERR(max14577->i2c_pmic)) {
 303                 dev_err(max14577->dev, "Failed to register PMIC I2C device\n");
 304                 return PTR_ERR(max14577->i2c_pmic);
 305         }
 306         i2c_set_clientdata(max14577->i2c_pmic, max14577);
 307
 308         max14577->regmap_pmic = devm_regmap_init_i2c(max14577->i2c_pmic,
 309                         &max77836_pmic_regmap_config);
 310         if (IS_ERR(max14577->regmap_pmic)) {
 311                 ret = PTR_ERR(max14577->regmap_pmic);
 312                 dev_err(max14577->dev, "Failed to allocate PMIC register map: %d\n",
 313                                 ret);
 314                 goto err;
 315         }
 316
 317         /* Un-mask MAX77836 Interrupt Source register */
 318         ret = max14577_read_reg(max14577->regmap_pmic,
 319                         MAX77836_PMIC_REG_INTSRC_MASK, &intsrc_mask);
 320         if (ret < 0) {
 321                 dev_err(max14577->dev, "Failed to read PMIC register\n");
 322                 goto err;
 323         }
 324
 325         intsrc_mask &= ~(MAX77836_INTSRC_MASK_TOP_INT_MASK);
 326         intsrc_mask &= ~(MAX77836_INTSRC_MASK_MUIC_CHG_INT_MASK);
 327         ret = max14577_write_reg(max14577->regmap_pmic,
 328                         MAX77836_PMIC_REG_INTSRC_MASK, intsrc_mask);
 329         if (ret < 0) {
 330                 dev_err(max14577->dev, "Failed to write PMIC register\n");
 331                 goto err;
 332         }
 333
 334         ret = regmap_add_irq_chip(max14577->regmap_pmic, max14577->irq,
 335                         IRQF_TRIGGER_FALLING | IRQF_ONESHOT | IRQF_SHARED,
 336                         0, &max77836_pmic_irq_chip,
 337                         &max14577->irq_data_pmic);
 338         if (ret != 0) {
 339                 dev_err(max14577->dev, "Failed to request PMIC IRQ %d: %d\n",
 340                                 max14577->irq, ret);
 341                 goto err;
 342         }
 343
 344         return 0;
 345
 346 err:
 347         i2c_unregister_device(max14577->i2c_pmic);
 348
 349         return ret;
 350 }
 351
 352 /*
 353  * Max77836 specific de-initialization code for driver remove.
 354  */
 355 static void max77836_remove(struct max14577 *max14577)
 356 {
 357         regmap_del_irq_chip(max14577->irq, max14577->irq_data_pmic);
 358         i2c_unregister_device(max14577->i2c_pmic);
 359 }
 360
 361 static int max14577_i2c_probe(struct i2c_client *i2c,
 362                               const struct i2c_device_id *id)
 363 {
 364         struct max14577 *max14577;
 365         struct max14577_platform_data *pdata = dev_get_platdata(&i2c->dev);
 366         struct device_node *np = i2c->dev.of_node;
 367         int ret = 0;
 368         const struct regmap_irq_chip *irq_chip;
 369         const struct mfd_cell *mfd_devs;
 370         unsigned int mfd_devs_size;
 371         int irq_flags;
 372
 373         if (np) {
 374                 pdata = devm_kzalloc(&i2c->dev, sizeof(*pdata), GFP_KERNEL);
 375                 if (!pdata)
 376                         return -ENOMEM;
 377                 i2c->dev.platform_data = pdata;
 378         }
 379
 380         if (!pdata) {
 381                 dev_err(&i2c->dev, "No platform data found.\n");
 382                 return -EINVAL;
 383         }
 384
 385         max14577 = devm_kzalloc(&i2c->dev, sizeof(*max14577), GFP_KERNEL);
 386         if (!max14577)
 387                 return -ENOMEM;
 388
 389         i2c_set_clientdata(i2c, max14577);
 390         max14577->dev = &i2c->dev;
 391         max14577->i2c = i2c;
 392         max14577->irq = i2c->irq;
 393
 394         max14577->regmap = devm_regmap_init_i2c(i2c,
 395                         &max14577_muic_regmap_config);
 396         if (IS_ERR(max14577->regmap)) {
 397                 ret = PTR_ERR(max14577->regmap);
 398                 dev_err(max14577->dev, "Failed to allocate register map: %d\n",
 399                                 ret);
 400                 return ret;
 401         }
 402
 403         if (np) {
 404                 const struct of_device_id *of_id;
 405
 406                 of_id = of_match_device(max14577_dt_match, &i2c->dev);
 407                 if (of_id)
 408                         max14577->dev_type =
 409                                 (enum maxim_device_type)of_id->data;
 410         } else {
 411                 max14577->dev_type = id->driver_data;
 412         }
 413
 414         max14577_print_dev_type(max14577);
 415
 416         switch (max14577->dev_type) {
 417         case MAXIM_DEVICE_TYPE_MAX77836:
 418                 irq_chip = &max77836_muic_irq_chip;
 419                 mfd_devs = max77836_devs;
 420                 mfd_devs_size = ARRAY_SIZE(max77836_devs);
 421                 irq_flags = IRQF_TRIGGER_FALLING | IRQF_ONESHOT | IRQF_SHARED;
 422                 break;
 423         case MAXIM_DEVICE_TYPE_MAX14577:
 424         default:
 425                 irq_chip = &max14577_irq_chip;
 426                 mfd_devs = max14577_devs;
 427                 mfd_devs_size = ARRAY_SIZE(max14577_devs);
 428                 irq_flags = IRQF_TRIGGER_FALLING | IRQF_ONESHOT;
 429                 break;
 430         }
 431
 432         ret = regmap_add_irq_chip(max14577->regmap, max14577->irq,
 433                                   irq_flags, 0, irq_chip,
 434                                   &max14577->irq_data);
 435         if (ret != 0) {
 436                 dev_err(&i2c->dev, "Failed to request IRQ %d: %d\n",
 437                                 max14577->irq, ret);
 438                 return ret;
 439         }
 440
 441         /* Max77836 specific initialization code (additional regmap) */
 442         if (max14577->dev_type == MAXIM_DEVICE_TYPE_MAX77836) {
 443                 ret = max77836_init(max14577);
 444                 if (ret < 0)
 445                         goto err_max77836;
 446         }
 447
 448         ret = mfd_add_devices(max14577->dev, -1, mfd_devs,
 449                         mfd_devs_size, NULL, 0, NULL);
 450         if (ret < 0)
 451                 goto err_mfd;
 452
 453         device_init_wakeup(max14577->dev, 1);
 454
 455         return 0;
 456
 457 err_mfd:
 458         if (max14577->dev_type == MAXIM_DEVICE_TYPE_MAX77836)
 459                 max77836_remove(max14577);
 460 err_max77836:
 461         regmap_del_irq_chip(max14577->irq, max14577->irq_data);
 462
 463         return ret;
 464 }
 465
 466 static int max14577_i2c_remove(struct i2c_client *i2c)
 467 {
 468         struct max14577 *max14577 = i2c_get_clientdata(i2c);
 469
 470         mfd_remove_devices(max14577->dev);
 471         regmap_del_irq_chip(max14577->irq, max14577->irq_data);
 472         if (max14577->dev_type == MAXIM_DEVICE_TYPE_MAX77836)
 473                 max77836_remove(max14577);
 474
 475         return 0;
 476 }
 477
 478 static const struct i2c_device_id max14577_i2c_id[] = {
 479         { "max14577", MAXIM_DEVICE_TYPE_MAX14577, },
 480         { "max77836", MAXIM_DEVICE_TYPE_MAX77836, },
 481         { }
 482 };
 483 MODULE_DEVICE_TABLE(i2c, max14577_i2c_id);
 484
 485 #ifdef CONFIG_PM_SLEEP
 486 static int max14577_suspend(struct device *dev)
 487 {
 488         struct i2c_client *i2c = to_i2c_client(dev);
 489         struct max14577 *max14577 = i2c_get_clientdata(i2c);
 490
 491         if (device_may_wakeup(dev))
 492                 enable_irq_wake(max14577->irq);
 493         /*
 494          * MUIC IRQ must be disabled during suspend because if it happens
 495          * while suspended it will be handled before resuming I2C.
 496          *
 497          * When device is woken up from suspend (e.g. by ADC change),
 498          * an interrupt occurs before resuming I2C bus controller.
 499          * Interrupt handler tries to read registers but this read
 500          * will fail because I2C is still suspended.
 501          */
 502         disable_irq(max14577->irq);
 503
 504         return 0;
 505 }
 506
 507 static int max14577_resume(struct device *dev)
 508 {
 509         struct i2c_client *i2c = to_i2c_client(dev);
 510         struct max14577 *max14577 = i2c_get_clientdata(i2c);
 511
 512         if (device_may_wakeup(dev))
 513                 disable_irq_wake(max14577->irq);
 514         enable_irq(max14577->irq);
 515
 516         return 0;
 517 }
 518 #endif /* CONFIG_PM_SLEEP */
 519
 520 static SIMPLE_DEV_PM_OPS(max14577_pm, max14577_suspend, max14577_resume);
 521
 522 static struct i2c_driver max14577_i2c_driver = {
 523         .driver = {
 524                 .name = "max14577",
 525                 .pm = &max14577_pm,
 526                 .of_match_table = max14577_dt_match,
 527         },
 528         .probe = max14577_i2c_probe,
 529         .remove = max14577_i2c_remove,
 530         .id_table = max14577_i2c_id,
 531 };
 532
 533 static int __init max14577_i2c_init(void)
 534 {
 535         BUILD_BUG_ON(ARRAY_SIZE(max14577_i2c_id) != MAXIM_DEVICE_TYPE_NUM);
 536         BUILD_BUG_ON(ARRAY_SIZE(max14577_dt_match) != MAXIM_DEVICE_TYPE_NUM);
 537
 538         /* Valid charger current values must be provided for each chipset */
 539         BUILD_BUG_ON(ARRAY_SIZE(maxim_charger_currents) != MAXIM_DEVICE_TYPE_NUM);
 540
 541         /* Check for valid values for charger */
 542         BUILD_BUG_ON(MAX14577_CHARGER_CURRENT_LIMIT_HIGH_START +
 543                         MAX14577_CHARGER_CURRENT_LIMIT_HIGH_STEP * 0xf !=
 544                         MAX14577_CHARGER_CURRENT_LIMIT_MAX);
 545         BUILD_BUG_ON(MAX14577_CHARGER_CURRENT_LIMIT_HIGH_STEP == 0);
 546
 547         BUILD_BUG_ON(MAX77836_CHARGER_CURRENT_LIMIT_HIGH_START +
 548                         MAX77836_CHARGER_CURRENT_LIMIT_HIGH_STEP * 0xf !=
 549                         MAX77836_CHARGER_CURRENT_LIMIT_MAX);
 550         BUILD_BUG_ON(MAX77836_CHARGER_CURRENT_LIMIT_HIGH_STEP == 0);
 551
 552         return i2c_add_driver(&max14577_i2c_driver);
 553 }
 554 module_init(max14577_i2c_init);
 555
 556 static void __exit max14577_i2c_exit(void)
 557 {
 558         i2c_del_driver(&max14577_i2c_driver);
 559 }
 560 module_exit(max14577_i2c_exit);
 561
 562 MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>, Krzysztof Kozlowski <krzk@kernel.org>");
 563 MODULE_DESCRIPTION("Maxim 14577/77836 multi-function core driver");
 564 MODULE_LICENSE("GPL");