drivers/regulator/max77686.c

   1 /*
   2  * max77686.c - Regulator driver for the Maxim 77686
   3  *
   4  * Copyright (C) 2012 Samsung Electronics
   5  * Chiwoong Byun <woong.byun@smasung.com>
   6  * Jonghwa Lee <jonghwa3.lee@samsung.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  *
  22  * This driver is based on max8997.c
  23  */
  24
  25 #include <linux/kernel.h>
  26 #include <linux/bug.h>
  27 #include <linux/err.h>
  28 #include <linux/gpio.h>
  29 #include <linux/slab.h>
  30 #include <linux/platform_device.h>
  31 #include <linux/regulator/driver.h>
  32 #include <linux/regulator/machine.h>
  33 #include <linux/regulator/of_regulator.h>
  34 #include <linux/mfd/max77686.h>
  35 #include <linux/mfd/max77686-private.h>
  36
  37 #define MAX77686_LDO_MINUV      800000
  38 #define MAX77686_LDO_UVSTEP     50000
  39 #define MAX77686_LDO_LOW_MINUV  800000
  40 #define MAX77686_LDO_LOW_UVSTEP 25000
  41 #define MAX77686_BUCK_MINUV     750000
  42 #define MAX77686_BUCK_UVSTEP    50000
  43 #define MAX77686_RAMP_DELAY     100000                  /* uV/us */
  44 #define MAX77686_DVS_RAMP_DELAY 27500                   /* uV/us */
  45 #define MAX77686_DVS_MINUV      600000
  46 #define MAX77686_DVS_UVSTEP     12500
  47
  48 #define MAX77686_OPMODE_SHIFT   6
  49 #define MAX77686_OPMODE_BUCK234_SHIFT   4
  50 #define MAX77686_OPMODE_MASK    0x3
  51
  52 #define MAX77686_VSEL_MASK      0x3F
  53 #define MAX77686_DVS_VSEL_MASK  0xFF
  54
  55 #define MAX77686_RAMP_RATE_MASK 0xC0
  56
  57 #define MAX77686_REGULATORS     MAX77686_REG_MAX
  58 #define MAX77686_LDOS           26
  59
  60 enum max77686_ramp_rate {
  61         RAMP_RATE_13P75MV,
  62         RAMP_RATE_27P5MV,
  63         RAMP_RATE_55MV,
  64         RAMP_RATE_NO_CTRL,      /* 100mV/us */
  65 };
  66
  67 struct max77686_data {
  68         struct regulator_dev *rdev[MAX77686_REGULATORS];
  69         unsigned int opmode[MAX77686_REGULATORS];
  70 };
  71
  72 /* Some BUCKS supports Normal[ON/OFF] mode during suspend */
  73 static int max77686_buck_set_suspend_disable(struct regulator_dev *rdev)
  74 {
  75         unsigned int val;
  76         struct max77686_data *max77686 = rdev_get_drvdata(rdev);
  77         int ret, id = rdev_get_id(rdev);
  78
  79         if (id == MAX77686_BUCK1)
  80                 val = 0x1;
  81         else
  82                 val = 0x1 << MAX77686_OPMODE_BUCK234_SHIFT;
  83
  84         ret = regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
  85                                  rdev->desc->enable_mask, val);
  86         if (ret)
  87                 return ret;
  88
  89         max77686->opmode[id] = val;
  90         return 0;
  91 }
  92
  93 /* Some LDOs supports [LPM/Normal]ON mode during suspend state */
  94 static int max77686_set_suspend_mode(struct regulator_dev *rdev,
  95                                      unsigned int mode)
  96 {
  97         struct max77686_data *max77686 = rdev_get_drvdata(rdev);
  98         unsigned int val;
  99         int ret, id = rdev_get_id(rdev);
 100
 101         /* BUCK[5-9] doesn't support this feature */
 102         if (id >= MAX77686_BUCK5)
 103                 return 0;
 104
 105         switch (mode) {
 106         case REGULATOR_MODE_IDLE:                       /* ON in LP Mode */
 107                 val = 0x2 << MAX77686_OPMODE_SHIFT;
 108                 break;
 109         case REGULATOR_MODE_NORMAL:                     /* ON in Normal Mode */
 110                 val = 0x3 << MAX77686_OPMODE_SHIFT;
 111                 break;
 112         default:
 113                 pr_warn("%s: regulator_suspend_mode : 0x%x not supported\n",
 114                         rdev->desc->name, mode);
 115                 return -EINVAL;
 116         }
 117
 118         ret = regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
 119                                   rdev->desc->enable_mask, val);
 120         if (ret)
 121                 return ret;
 122
 123         max77686->opmode[id] = val;
 124         return 0;
 125 }
 126
 127 /* Some LDOs supports LPM-ON/OFF/Normal-ON mode during suspend state */
 128 static int max77686_ldo_set_suspend_mode(struct regulator_dev *rdev,
 129                                      unsigned int mode)
 130 {
 131         unsigned int val;
 132         struct max77686_data *max77686 = rdev_get_drvdata(rdev);
 133         int ret;
 134
 135         switch (mode) {
 136         case REGULATOR_MODE_STANDBY:                    /* switch off */
 137                 val = 0x1 << MAX77686_OPMODE_SHIFT;
 138                 break;
 139         case REGULATOR_MODE_IDLE:                       /* ON in LP Mode */
 140                 val = 0x2 << MAX77686_OPMODE_SHIFT;
 141                 break;
 142         case REGULATOR_MODE_NORMAL:                     /* ON in Normal Mode */
 143                 val = 0x3 << MAX77686_OPMODE_SHIFT;
 144                 break;
 145         default:
 146                 pr_warn("%s: regulator_suspend_mode : 0x%x not supported\n",
 147                         rdev->desc->name, mode);
 148                 return -EINVAL;
 149         }
 150
 151         ret = regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
 152                                  rdev->desc->enable_mask, val);
 153         if (ret)
 154                 return ret;
 155
 156         max77686->opmode[rdev_get_id(rdev)] = val;
 157         return 0;
 158 }
 159
 160 static int max77686_enable(struct regulator_dev *rdev)
 161 {
 162         struct max77686_data *max77686 = rdev_get_drvdata(rdev);
 163
 164         return regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
 165                                   rdev->desc->enable_mask,
 166                                   max77686->opmode[rdev_get_id(rdev)]);
 167 }
 168
 169 static int max77686_set_ramp_delay(struct regulator_dev *rdev, int ramp_delay)
 170 {
 171         unsigned int ramp_value = RAMP_RATE_NO_CTRL;
 172
 173         switch (ramp_delay) {
 174         case 1 ... 13750:
 175                 ramp_value = RAMP_RATE_13P75MV;
 176                 break;
 177         case 13751 ... 27500:
 178                 ramp_value = RAMP_RATE_27P5MV;
 179                 break;
 180         case 27501 ... 55000:
 181                 ramp_value = RAMP_RATE_55MV;
 182                 break;
 183         case 55001 ... 100000:
 184                 break;
 185         default:
 186                 pr_warn("%s: ramp_delay: %d not supported, setting 100000\n",
 187                         rdev->desc->name, ramp_delay);
 188         }
 189
 190         return regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
 191                                   MAX77686_RAMP_RATE_MASK, ramp_value << 6);
 192 }
 193
 194 static struct regulator_ops max77686_ops = {
 195         .list_voltage           = regulator_list_voltage_linear,
 196         .map_voltage            = regulator_map_voltage_linear,
 197         .is_enabled             = regulator_is_enabled_regmap,
 198         .enable                 = max77686_enable,
 199         .disable                = regulator_disable_regmap,
 200         .get_voltage_sel        = regulator_get_voltage_sel_regmap,
 201         .set_voltage_sel        = regulator_set_voltage_sel_regmap,
 202         .set_voltage_time_sel   = regulator_set_voltage_time_sel,
 203         .set_suspend_mode       = max77686_set_suspend_mode,
 204 };
 205
 206 static struct regulator_ops max77686_ldo_ops = {
 207         .list_voltage           = regulator_list_voltage_linear,
 208         .map_voltage            = regulator_map_voltage_linear,
 209         .is_enabled             = regulator_is_enabled_regmap,
 210         .enable                 = max77686_enable,
 211         .disable                = regulator_disable_regmap,
 212         .get_voltage_sel        = regulator_get_voltage_sel_regmap,
 213         .set_voltage_sel        = regulator_set_voltage_sel_regmap,
 214         .set_voltage_time_sel   = regulator_set_voltage_time_sel,
 215         .set_suspend_mode       = max77686_ldo_set_suspend_mode,
 216 };
 217
 218 static struct regulator_ops max77686_buck1_ops = {
 219         .list_voltage           = regulator_list_voltage_linear,
 220         .map_voltage            = regulator_map_voltage_linear,
 221         .is_enabled             = regulator_is_enabled_regmap,
 222         .enable                 = max77686_enable,
 223         .disable                = regulator_disable_regmap,
 224         .get_voltage_sel        = regulator_get_voltage_sel_regmap,
 225         .set_voltage_sel        = regulator_set_voltage_sel_regmap,
 226         .set_voltage_time_sel   = regulator_set_voltage_time_sel,
 227         .set_suspend_disable    = max77686_buck_set_suspend_disable,
 228 };
 229
 230 static struct regulator_ops max77686_buck_dvs_ops = {
 231         .list_voltage           = regulator_list_voltage_linear,
 232         .map_voltage            = regulator_map_voltage_linear,
 233         .is_enabled             = regulator_is_enabled_regmap,
 234         .enable                 = max77686_enable,
 235         .disable                = regulator_disable_regmap,
 236         .get_voltage_sel        = regulator_get_voltage_sel_regmap,
 237         .set_voltage_sel        = regulator_set_voltage_sel_regmap,
 238         .set_voltage_time_sel   = regulator_set_voltage_time_sel,
 239         .set_ramp_delay         = max77686_set_ramp_delay,
 240         .set_suspend_disable    = max77686_buck_set_suspend_disable,
 241 };
 242
 243 #define regulator_desc_ldo(num)         {                               \
 244         .name           = "LDO"#num,                                    \
 245         .id             = MAX77686_LDO##num,                            \
 246         .ops            = &max77686_ops,                                \
 247         .type           = REGULATOR_VOLTAGE,                            \
 248         .owner          = THIS_MODULE,                                  \
 249         .min_uV         = MAX77686_LDO_MINUV,                           \
 250         .uV_step        = MAX77686_LDO_UVSTEP,                          \
 251         .ramp_delay     = MAX77686_RAMP_DELAY,                          \
 252         .n_voltages     = MAX77686_VSEL_MASK + 1,                       \
 253         .vsel_reg       = MAX77686_REG_LDO1CTRL1 + num - 1,             \
 254         .vsel_mask      = MAX77686_VSEL_MASK,                           \
 255         .enable_reg     = MAX77686_REG_LDO1CTRL1 + num - 1,             \
 256         .enable_mask    = MAX77686_OPMODE_MASK                          \
 257                         << MAX77686_OPMODE_SHIFT,                       \
 258 }
 259 #define regulator_desc_lpm_ldo(num)     {                               \
 260         .name           = "LDO"#num,                                    \
 261         .id             = MAX77686_LDO##num,                            \
 262         .ops            = &max77686_ldo_ops,                            \
 263         .type           = REGULATOR_VOLTAGE,                            \
 264         .owner          = THIS_MODULE,                                  \
 265         .min_uV         = MAX77686_LDO_MINUV,                           \
 266         .uV_step        = MAX77686_LDO_UVSTEP,                          \
 267         .ramp_delay     = MAX77686_RAMP_DELAY,                          \
 268         .n_voltages     = MAX77686_VSEL_MASK + 1,                       \
 269         .vsel_reg       = MAX77686_REG_LDO1CTRL1 + num - 1,             \
 270         .vsel_mask      = MAX77686_VSEL_MASK,                           \
 271         .enable_reg     = MAX77686_REG_LDO1CTRL1 + num - 1,             \
 272         .enable_mask    = MAX77686_OPMODE_MASK                          \
 273                         << MAX77686_OPMODE_SHIFT,                       \
 274 }
 275 #define regulator_desc_ldo_low(num)             {                       \
 276         .name           = "LDO"#num,                                    \
 277         .id             = MAX77686_LDO##num,                            \
 278         .ops            = &max77686_ldo_ops,                            \
 279         .type           = REGULATOR_VOLTAGE,                            \
 280         .owner          = THIS_MODULE,                                  \
 281         .min_uV         = MAX77686_LDO_LOW_MINUV,                       \
 282         .uV_step        = MAX77686_LDO_LOW_UVSTEP,                      \
 283         .ramp_delay     = MAX77686_RAMP_DELAY,                          \
 284         .n_voltages     = MAX77686_VSEL_MASK + 1,                       \
 285         .vsel_reg       = MAX77686_REG_LDO1CTRL1 + num - 1,             \
 286         .vsel_mask      = MAX77686_VSEL_MASK,                           \
 287         .enable_reg     = MAX77686_REG_LDO1CTRL1 + num - 1,             \
 288         .enable_mask    = MAX77686_OPMODE_MASK                          \
 289                         << MAX77686_OPMODE_SHIFT,                       \
 290 }
 291 #define regulator_desc_ldo1_low(num)            {                       \
 292         .name           = "LDO"#num,                                    \
 293         .id             = MAX77686_LDO##num,                            \
 294         .ops            = &max77686_ops,                                \
 295         .type           = REGULATOR_VOLTAGE,                            \
 296         .owner          = THIS_MODULE,                                  \
 297         .min_uV         = MAX77686_LDO_LOW_MINUV,                       \
 298         .uV_step        = MAX77686_LDO_LOW_UVSTEP,                      \
 299         .ramp_delay     = MAX77686_RAMP_DELAY,                          \
 300         .n_voltages     = MAX77686_VSEL_MASK + 1,                       \
 301         .vsel_reg       = MAX77686_REG_LDO1CTRL1 + num - 1,             \
 302         .vsel_mask      = MAX77686_VSEL_MASK,                           \
 303         .enable_reg     = MAX77686_REG_LDO1CTRL1 + num - 1,             \
 304         .enable_mask    = MAX77686_OPMODE_MASK                          \
 305                         << MAX77686_OPMODE_SHIFT,                       \
 306 }
 307 #define regulator_desc_buck(num)                {                       \
 308         .name           = "BUCK"#num,                                   \
 309         .id             = MAX77686_BUCK##num,                           \
 310         .ops            = &max77686_ops,                                \
 311         .type           = REGULATOR_VOLTAGE,                            \
 312         .owner          = THIS_MODULE,                                  \
 313         .min_uV         = MAX77686_BUCK_MINUV,                          \
 314         .uV_step        = MAX77686_BUCK_UVSTEP,                         \
 315         .ramp_delay     = MAX77686_RAMP_DELAY,                          \
 316         .n_voltages     = MAX77686_VSEL_MASK + 1,                       \
 317         .vsel_reg       = MAX77686_REG_BUCK5OUT + (num - 5) * 2,        \
 318         .vsel_mask      = MAX77686_VSEL_MASK,                           \
 319         .enable_reg     = MAX77686_REG_BUCK5CTRL + (num - 5) * 2,       \
 320         .enable_mask    = MAX77686_OPMODE_MASK,                         \
 321 }
 322 #define regulator_desc_buck1(num)               {                       \
 323         .name           = "BUCK"#num,                                   \
 324         .id             = MAX77686_BUCK##num,                           \
 325         .ops            = &max77686_buck1_ops,                          \
 326         .type           = REGULATOR_VOLTAGE,                            \
 327         .owner          = THIS_MODULE,                                  \
 328         .min_uV         = MAX77686_BUCK_MINUV,                          \
 329         .uV_step        = MAX77686_BUCK_UVSTEP,                         \
 330         .ramp_delay     = MAX77686_RAMP_DELAY,                          \
 331         .n_voltages     = MAX77686_VSEL_MASK + 1,                       \
 332         .vsel_reg       = MAX77686_REG_BUCK1OUT,                        \
 333         .vsel_mask      = MAX77686_VSEL_MASK,                           \
 334         .enable_reg     = MAX77686_REG_BUCK1CTRL,                       \
 335         .enable_mask    = MAX77686_OPMODE_MASK,                         \
 336 }
 337 #define regulator_desc_buck_dvs(num)            {                       \
 338         .name           = "BUCK"#num,                                   \
 339         .id             = MAX77686_BUCK##num,                           \
 340         .ops            = &max77686_buck_dvs_ops,                       \
 341         .type           = REGULATOR_VOLTAGE,                            \
 342         .owner          = THIS_MODULE,                                  \
 343         .min_uV         = MAX77686_DVS_MINUV,                           \
 344         .uV_step        = MAX77686_DVS_UVSTEP,                          \
 345         .ramp_delay     = MAX77686_DVS_RAMP_DELAY,                      \
 346         .n_voltages     = MAX77686_DVS_VSEL_MASK + 1,                   \
 347         .vsel_reg       = MAX77686_REG_BUCK2DVS1 + (num - 2) * 10,      \
 348         .vsel_mask      = MAX77686_DVS_VSEL_MASK,                       \
 349         .enable_reg     = MAX77686_REG_BUCK2CTRL1 + (num - 2) * 10,     \
 350         .enable_mask    = MAX77686_OPMODE_MASK                          \
 351                         << MAX77686_OPMODE_BUCK234_SHIFT,               \
 352 }
 353
 354 static struct regulator_desc regulators[] = {
 355         regulator_desc_ldo1_low(1),
 356         regulator_desc_ldo_low(2),
 357         regulator_desc_ldo(3),
 358         regulator_desc_ldo(4),
 359         regulator_desc_ldo(5),
 360         regulator_desc_ldo_low(6),
 361         regulator_desc_ldo_low(7),
 362         regulator_desc_ldo_low(8),
 363         regulator_desc_ldo(9),
 364         regulator_desc_lpm_ldo(10),
 365         regulator_desc_lpm_ldo(11),
 366         regulator_desc_lpm_ldo(12),
 367         regulator_desc_ldo(13),
 368         regulator_desc_lpm_ldo(14),
 369         regulator_desc_ldo_low(15),
 370         regulator_desc_lpm_ldo(16),
 371         regulator_desc_ldo(17),
 372         regulator_desc_ldo(18),
 373         regulator_desc_ldo(19),
 374         regulator_desc_ldo(20),
 375         regulator_desc_ldo(21),
 376         regulator_desc_ldo(22),
 377         regulator_desc_ldo(23),
 378         regulator_desc_ldo(24),
 379         regulator_desc_ldo(25),
 380         regulator_desc_ldo(26),
 381         regulator_desc_buck1(1),
 382         regulator_desc_buck_dvs(2),
 383         regulator_desc_buck_dvs(3),
 384         regulator_desc_buck_dvs(4),
 385         regulator_desc_buck(5),
 386         regulator_desc_buck(6),
 387         regulator_desc_buck(7),
 388         regulator_desc_buck(8),
 389         regulator_desc_buck(9),
 390 };
 391
 392 #ifdef CONFIG_OF
 393 static int max77686_pmic_dt_parse_pdata(struct platform_device *pdev,
 394                                         struct max77686_platform_data *pdata)
 395 {
 396         struct max77686_dev *iodev = dev_get_drvdata(pdev->dev.parent);
 397         struct device_node *pmic_np, *regulators_np;
 398         struct max77686_regulator_data *rdata;
 399         struct of_regulator_match rmatch;
 400         unsigned int i;
 401
 402         pmic_np = iodev->dev->of_node;
 403         regulators_np = of_find_node_by_name(pmic_np, "voltage-regulators");
 404         if (!regulators_np) {
 405                 dev_err(&pdev->dev, "could not find regulators sub-node\n");
 406                 return -EINVAL;
 407         }
 408
 409         pdata->num_regulators = ARRAY_SIZE(regulators);
 410         rdata = devm_kzalloc(&pdev->dev, sizeof(*rdata) *
 411                              pdata->num_regulators, GFP_KERNEL);
 412         if (!rdata) {
 413                 dev_err(&pdev->dev,
 414                         "could not allocate memory for regulator data\n");
 415                 return -ENOMEM;
 416         }
 417
 418         for (i = 0; i < pdata->num_regulators; i++) {
 419                 rmatch.name = regulators[i].name;
 420                 rmatch.init_data = NULL;
 421                 rmatch.of_node = NULL;
 422                 of_regulator_match(&pdev->dev, regulators_np, &rmatch, 1);
 423                 rdata[i].initdata = rmatch.init_data;
 424                 rdata[i].of_node = rmatch.of_node;
 425         }
 426
 427         pdata->regulators = rdata;
 428
 429         return 0;
 430 }
 431 #else
 432 static int max77686_pmic_dt_parse_pdata(struct platform_device *pdev,
 433                                         struct max77686_platform_data *pdata)
 434 {
 435         return 0;
 436 }
 437 #endif /* CONFIG_OF */
 438
 439 static int max77686_pmic_probe(struct platform_device *pdev)
 440 {
 441         struct max77686_dev *iodev = dev_get_drvdata(pdev->dev.parent);
 442         struct max77686_platform_data *pdata = dev_get_platdata(iodev->dev);
 443         struct max77686_data *max77686;
 444         int i, ret = 0;
 445         struct regulator_config config = { };
 446
 447         dev_dbg(&pdev->dev, "%s\n", __func__);
 448
 449         if (!pdata) {
 450                 dev_err(&pdev->dev, "no platform data found for regulator\n");
 451                 return -ENODEV;
 452         }
 453
 454         if (iodev->dev->of_node) {
 455                 ret = max77686_pmic_dt_parse_pdata(pdev, pdata);
 456                 if (ret)
 457                         return ret;
 458         }
 459
 460         if (pdata->num_regulators != MAX77686_REGULATORS) {
 461                 dev_err(&pdev->dev,
 462                         "Invalid initial data for regulator's initialiation\n");
 463                 return -EINVAL;
 464         }
 465
 466         max77686 = devm_kzalloc(&pdev->dev, sizeof(struct max77686_data),
 467                                 GFP_KERNEL);
 468         if (!max77686)
 469                 return -ENOMEM;
 470
 471         config.dev = &pdev->dev;
 472         config.regmap = iodev->regmap;
 473         config.driver_data = max77686;
 474         platform_set_drvdata(pdev, max77686);
 475
 476         for (i = 0; i < MAX77686_REGULATORS; i++) {
 477                 config.init_data = pdata->regulators[i].initdata;
 478                 config.of_node = pdata->regulators[i].of_node;
 479
 480                 max77686->opmode[i] = regulators[i].enable_mask;
 481                 max77686->rdev[i] = devm_regulator_register(&pdev->dev,
 482                                                 &regulators[i], &config);
 483                 if (IS_ERR(max77686->rdev[i])) {
 484                         dev_err(&pdev->dev,
 485                                 "regulator init failed for %d\n", i);
 486                         return PTR_ERR(max77686->rdev[i]);
 487                 }
 488         }
 489
 490         return 0;
 491 }
 492
 493 static const struct platform_device_id max77686_pmic_id[] = {
 494         {"max77686-pmic", 0},
 495         { },
 496 };
 497 MODULE_DEVICE_TABLE(platform, max77686_pmic_id);
 498
 499 static struct platform_driver max77686_pmic_driver = {
 500         .driver = {
 501                 .name = "max77686-pmic",
 502                 .owner = THIS_MODULE,
 503         },
 504         .probe = max77686_pmic_probe,
 505         .id_table = max77686_pmic_id,
 506 };
 507
 508 static int __init max77686_pmic_init(void)
 509 {
 510         return platform_driver_register(&max77686_pmic_driver);
 511 }
 512 subsys_initcall(max77686_pmic_init);
 513
 514 static void __exit max77686_pmic_cleanup(void)
 515 {
 516         platform_driver_unregister(&max77686_pmic_driver);
 517 }
 518 module_exit(max77686_pmic_cleanup);
 519
 520 MODULE_DESCRIPTION("MAXIM 77686 Regulator Driver");
 521 MODULE_AUTHOR("Chiwoong Byun <woong.byun@samsung.com>");
 522 MODULE_LICENSE("GPL");