drivers/regulator/lp3972.c

   1 /*
   2  * Regulator driver for National Semiconductors LP3972 PMIC chip
   3  *
   4  * Based on lp3971.c
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  */
  11
  12 #include <linux/bug.h>
  13 #include <linux/err.h>
  14 #include <linux/i2c.h>
  15 #include <linux/module.h>
  16 #include <linux/kernel.h>
  17 #include <linux/regulator/driver.h>
  18 #include <linux/regulator/lp3972.h>
  19 #include <linux/slab.h>
  20
  21 struct lp3972 {
  22         struct device *dev;
  23         struct mutex io_lock;
  24         struct i2c_client *i2c;
  25         int num_regulators;
  26         struct regulator_dev **rdev;
  27 };
  28
  29 /* LP3972 Control Registers */
  30 #define LP3972_SCR_REG          0x07
  31 #define LP3972_OVER1_REG        0x10
  32 #define LP3972_OVSR1_REG        0x11
  33 #define LP3972_OVER2_REG        0x12
  34 #define LP3972_OVSR2_REG        0x13
  35 #define LP3972_VCC1_REG         0x20
  36 #define LP3972_ADTV1_REG        0x23
  37 #define LP3972_ADTV2_REG        0x24
  38 #define LP3972_AVRC_REG         0x25
  39 #define LP3972_CDTC1_REG        0x26
  40 #define LP3972_CDTC2_REG        0x27
  41 #define LP3972_SDTV1_REG        0x29
  42 #define LP3972_SDTV2_REG        0x2A
  43 #define LP3972_MDTV1_REG        0x32
  44 #define LP3972_MDTV2_REG        0x33
  45 #define LP3972_L2VCR_REG        0x39
  46 #define LP3972_L34VCR_REG       0x3A
  47 #define LP3972_SCR1_REG         0x80
  48 #define LP3972_SCR2_REG         0x81
  49 #define LP3972_OEN3_REG         0x82
  50 #define LP3972_OSR3_REG         0x83
  51 #define LP3972_LOER4_REG        0x84
  52 #define LP3972_B2TV_REG         0x85
  53 #define LP3972_B3TV_REG         0x86
  54 #define LP3972_B32RC_REG        0x87
  55 #define LP3972_ISRA_REG         0x88
  56 #define LP3972_BCCR_REG         0x89
  57 #define LP3972_II1RR_REG        0x8E
  58 #define LP3972_II2RR_REG        0x8F
  59
  60 #define LP3972_SYS_CONTROL1_REG         LP3972_SCR1_REG
  61 /* System control register 1 initial value,
  62  * bits 5, 6 and 7 are EPROM programmable */
  63 #define SYS_CONTROL1_INIT_VAL           0x02
  64 #define SYS_CONTROL1_INIT_MASK          0x1F
  65
  66 #define LP3972_VOL_CHANGE_REG           LP3972_VCC1_REG
  67 #define LP3972_VOL_CHANGE_FLAG_GO       0x01
  68 #define LP3972_VOL_CHANGE_FLAG_MASK     0x03
  69
  70 /* LDO output enable mask */
  71 #define LP3972_OEN3_L1EN        BIT(0)
  72 #define LP3972_OVER2_LDO2_EN    BIT(2)
  73 #define LP3972_OVER2_LDO3_EN    BIT(3)
  74 #define LP3972_OVER2_LDO4_EN    BIT(4)
  75 #define LP3972_OVER1_S_EN       BIT(2)
  76
  77 static const unsigned int ldo1_voltage_map[] = {
  78         1700000, 1725000, 1750000, 1775000, 1800000, 1825000, 1850000, 1875000,
  79         1900000, 1925000, 1950000, 1975000, 2000000,
  80 };
  81
  82 static const unsigned int ldo23_voltage_map[] = {
  83         1800000, 1900000, 2000000, 2100000, 2200000, 2300000, 2400000, 2500000,
  84         2600000, 2700000, 2800000, 2900000, 3000000, 3100000, 3200000, 3300000,
  85 };
  86
  87 static const unsigned int ldo4_voltage_map[] = {
  88         1000000, 1050000, 1100000, 1150000, 1200000, 1250000, 1300000, 1350000,
  89         1400000, 1500000, 1800000, 1900000, 2500000, 2800000, 3000000, 3300000,
  90 };
  91
  92 static const unsigned int ldo5_voltage_map[] = {
  93               0,       0,       0,       0,       0,  850000,  875000,  900000,
  94          925000,  950000,  975000, 1000000, 1025000, 1050000, 1075000, 1100000,
  95         1125000, 1150000, 1175000, 1200000, 1225000, 1250000, 1275000, 1300000,
  96         1325000, 1350000, 1375000, 1400000, 1425000, 1450000, 1475000, 1500000,
  97 };
  98
  99 static const unsigned int buck1_voltage_map[] = {
 100          725000,  750000,  775000,  800000,  825000,  850000,  875000,  900000,
 101          925000,  950000,  975000, 1000000, 1025000, 1050000, 1075000, 1100000,
 102         1125000, 1150000, 1175000, 1200000, 1225000, 1250000, 1275000, 1300000,
 103         1325000, 1350000, 1375000, 1400000, 1425000, 1450000, 1475000, 1500000,
 104 };
 105
 106 static const unsigned int buck23_voltage_map[] = {
 107               0,  800000,  850000,  900000,  950000, 1000000, 1050000, 1100000,
 108         1150000, 1200000, 1250000, 1300000, 1350000, 1400000, 1450000, 1500000,
 109         1550000, 1600000, 1650000, 1700000, 1800000, 1900000, 2500000, 2800000,
 110         3000000, 3300000,
 111 };
 112
 113 static const int ldo_output_enable_mask[] = {
 114         LP3972_OEN3_L1EN,
 115         LP3972_OVER2_LDO2_EN,
 116         LP3972_OVER2_LDO3_EN,
 117         LP3972_OVER2_LDO4_EN,
 118         LP3972_OVER1_S_EN,
 119 };
 120
 121 static const int ldo_output_enable_addr[] = {
 122         LP3972_OEN3_REG,
 123         LP3972_OVER2_REG,
 124         LP3972_OVER2_REG,
 125         LP3972_OVER2_REG,
 126         LP3972_OVER1_REG,
 127 };
 128
 129 static const int ldo_vol_ctl_addr[] = {
 130         LP3972_MDTV1_REG,
 131         LP3972_L2VCR_REG,
 132         LP3972_L34VCR_REG,
 133         LP3972_L34VCR_REG,
 134         LP3972_SDTV1_REG,
 135 };
 136
 137 static const int buck_vol_enable_addr[] = {
 138         LP3972_OVER1_REG,
 139         LP3972_OEN3_REG,
 140         LP3972_OEN3_REG,
 141 };
 142
 143 static const int buck_base_addr[] = {
 144         LP3972_ADTV1_REG,
 145         LP3972_B2TV_REG,
 146         LP3972_B3TV_REG,
 147 };
 148
 149 #define LP3972_LDO_OUTPUT_ENABLE_MASK(x) (ldo_output_enable_mask[x])
 150 #define LP3972_LDO_OUTPUT_ENABLE_REG(x) (ldo_output_enable_addr[x])
 151
 152 /*      LDO voltage control registers shift:
 153         LP3972_LDO1 -> 0, LP3972_LDO2 -> 4
 154         LP3972_LDO3 -> 0, LP3972_LDO4 -> 4
 155         LP3972_LDO5 -> 0
 156 */
 157 #define LP3972_LDO_VOL_CONTR_SHIFT(x) (((x) & 1) << 2)
 158 #define LP3972_LDO_VOL_CONTR_REG(x) (ldo_vol_ctl_addr[x])
 159 #define LP3972_LDO_VOL_CHANGE_SHIFT(x) ((x) ? 4 : 6)
 160
 161 #define LP3972_LDO_VOL_MASK(x) (((x) % 4) ? 0x0f : 0x1f)
 162 #define LP3972_LDO_VOL_MIN_IDX(x) (((x) == 4) ? 0x05 : 0x00)
 163 #define LP3972_LDO_VOL_MAX_IDX(x) ((x) ? (((x) == 4) ? 0x1f : 0x0f) : 0x0c)
 164
 165 #define LP3972_BUCK_VOL_ENABLE_REG(x) (buck_vol_enable_addr[x])
 166 #define LP3972_BUCK_VOL1_REG(x) (buck_base_addr[x])
 167 #define LP3972_BUCK_VOL_MASK 0x1f
 168
 169 static int lp3972_i2c_read(struct i2c_client *i2c, char reg, int count,
 170         u16 *dest)
 171 {
 172         int ret;
 173
 174         if (count != 1)
 175                 return -EIO;
 176         ret = i2c_smbus_read_byte_data(i2c, reg);
 177         if (ret < 0)
 178                 return ret;
 179
 180         *dest = ret;
 181         return 0;
 182 }
 183
 184 static int lp3972_i2c_write(struct i2c_client *i2c, char reg, int count,
 185         const u16 *src)
 186 {
 187         if (count != 1)
 188                 return -EIO;
 189         return i2c_smbus_write_byte_data(i2c, reg, *src);
 190 }
 191
 192 static u8 lp3972_reg_read(struct lp3972 *lp3972, u8 reg)
 193 {
 194         u16 val = 0;
 195
 196         mutex_lock(&lp3972->io_lock);
 197
 198         lp3972_i2c_read(lp3972->i2c, reg, 1, &val);
 199
 200         dev_dbg(lp3972->dev, "reg read 0x%02x -> 0x%02x\n", (int)reg,
 201                 (unsigned)val & 0xff);
 202
 203         mutex_unlock(&lp3972->io_lock);
 204
 205         return val & 0xff;
 206 }
 207
 208 static int lp3972_set_bits(struct lp3972 *lp3972, u8 reg, u16 mask, u16 val)
 209 {
 210         u16 tmp;
 211         int ret;
 212
 213         mutex_lock(&lp3972->io_lock);
 214
 215         ret = lp3972_i2c_read(lp3972->i2c, reg, 1, &tmp);
 216         tmp = (tmp & ~mask) | val;
 217         if (ret == 0) {
 218                 ret = lp3972_i2c_write(lp3972->i2c, reg, 1, &tmp);
 219                 dev_dbg(lp3972->dev, "reg write 0x%02x -> 0x%02x\n", (int)reg,
 220                         (unsigned)val & 0xff);
 221         }
 222         mutex_unlock(&lp3972->io_lock);
 223
 224         return ret;
 225 }
 226
 227 static int lp3972_ldo_is_enabled(struct regulator_dev *dev)
 228 {
 229         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 230         int ldo = rdev_get_id(dev) - LP3972_LDO1;
 231         u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);
 232         u16 val;
 233
 234         val = lp3972_reg_read(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo));
 235         return !!(val & mask);
 236 }
 237
 238 static int lp3972_ldo_enable(struct regulator_dev *dev)
 239 {
 240         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 241         int ldo = rdev_get_id(dev) - LP3972_LDO1;
 242         u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);
 243
 244         return lp3972_set_bits(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo),
 245                                 mask, mask);
 246 }
 247
 248 static int lp3972_ldo_disable(struct regulator_dev *dev)
 249 {
 250         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 251         int ldo = rdev_get_id(dev) - LP3972_LDO1;
 252         u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);
 253
 254         return lp3972_set_bits(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo),
 255                                 mask, 0);
 256 }
 257
 258 static int lp3972_ldo_get_voltage_sel(struct regulator_dev *dev)
 259 {
 260         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 261         int ldo = rdev_get_id(dev) - LP3972_LDO1;
 262         u16 mask = LP3972_LDO_VOL_MASK(ldo);
 263         u16 val, reg;
 264
 265         reg = lp3972_reg_read(lp3972, LP3972_LDO_VOL_CONTR_REG(ldo));
 266         val = (reg >> LP3972_LDO_VOL_CONTR_SHIFT(ldo)) & mask;
 267
 268         return val;
 269 }
 270
 271 static int lp3972_ldo_set_voltage_sel(struct regulator_dev *dev,
 272                                       unsigned int selector)
 273 {
 274         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 275         int ldo = rdev_get_id(dev) - LP3972_LDO1;
 276         int shift, ret;
 277
 278         shift = LP3972_LDO_VOL_CONTR_SHIFT(ldo);
 279         ret = lp3972_set_bits(lp3972, LP3972_LDO_VOL_CONTR_REG(ldo),
 280                 LP3972_LDO_VOL_MASK(ldo) << shift, selector << shift);
 281
 282         if (ret)
 283                 return ret;
 284
 285         /*
 286          * LDO1 and LDO5 support voltage control by either target voltage1
 287          * or target voltage2 register.
 288          * We use target voltage1 register for LDO1 and LDO5 in this driver.
 289          * We need to update voltage change control register(0x20) to enable
 290          * LDO1 and LDO5 to change to their programmed target values.
 291          */
 292         switch (ldo) {
 293         case LP3972_LDO1:
 294         case LP3972_LDO5:
 295                 shift = LP3972_LDO_VOL_CHANGE_SHIFT(ldo);
 296                 ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
 297                         LP3972_VOL_CHANGE_FLAG_MASK << shift,
 298                         LP3972_VOL_CHANGE_FLAG_GO << shift);
 299                 if (ret)
 300                         return ret;
 301
 302                 ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
 303                         LP3972_VOL_CHANGE_FLAG_MASK << shift, 0);
 304                 break;
 305         }
 306
 307         return ret;
 308 }
 309
 310 static struct regulator_ops lp3972_ldo_ops = {
 311         .list_voltage = regulator_list_voltage_table,
 312         .is_enabled = lp3972_ldo_is_enabled,
 313         .enable = lp3972_ldo_enable,
 314         .disable = lp3972_ldo_disable,
 315         .get_voltage_sel = lp3972_ldo_get_voltage_sel,
 316         .set_voltage_sel = lp3972_ldo_set_voltage_sel,
 317 };
 318
 319 static int lp3972_dcdc_is_enabled(struct regulator_dev *dev)
 320 {
 321         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 322         int buck = rdev_get_id(dev) - LP3972_DCDC1;
 323         u16 mask = 1 << (buck * 2);
 324         u16 val;
 325
 326         val = lp3972_reg_read(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck));
 327         return !!(val & mask);
 328 }
 329
 330 static int lp3972_dcdc_enable(struct regulator_dev *dev)
 331 {
 332         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 333         int buck = rdev_get_id(dev) - LP3972_DCDC1;
 334         u16 mask = 1 << (buck * 2);
 335         u16 val;
 336
 337         val = lp3972_set_bits(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck),
 338                                 mask, mask);
 339         return val;
 340 }
 341
 342 static int lp3972_dcdc_disable(struct regulator_dev *dev)
 343 {
 344         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 345         int buck = rdev_get_id(dev) - LP3972_DCDC1;
 346         u16 mask = 1 << (buck * 2);
 347         u16 val;
 348
 349         val = lp3972_set_bits(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck),
 350                                 mask, 0);
 351         return val;
 352 }
 353
 354 static int lp3972_dcdc_get_voltage_sel(struct regulator_dev *dev)
 355 {
 356         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 357         int buck = rdev_get_id(dev) - LP3972_DCDC1;
 358         u16 reg;
 359
 360         reg = lp3972_reg_read(lp3972, LP3972_BUCK_VOL1_REG(buck));
 361         reg &= LP3972_BUCK_VOL_MASK;
 362
 363         return reg;
 364 }
 365
 366 static int lp3972_dcdc_set_voltage_sel(struct regulator_dev *dev,
 367                                        unsigned int selector)
 368 {
 369         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 370         int buck = rdev_get_id(dev) - LP3972_DCDC1;
 371         int ret;
 372
 373         ret = lp3972_set_bits(lp3972, LP3972_BUCK_VOL1_REG(buck),
 374                                 LP3972_BUCK_VOL_MASK, selector);
 375         if (ret)
 376                 return ret;
 377
 378         if (buck != 0)
 379                 return ret;
 380
 381         ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
 382                 LP3972_VOL_CHANGE_FLAG_MASK, LP3972_VOL_CHANGE_FLAG_GO);
 383         if (ret)
 384                 return ret;
 385
 386         return lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
 387                                 LP3972_VOL_CHANGE_FLAG_MASK, 0);
 388 }
 389
 390 static struct regulator_ops lp3972_dcdc_ops = {
 391         .list_voltage = regulator_list_voltage_table,
 392         .is_enabled = lp3972_dcdc_is_enabled,
 393         .enable = lp3972_dcdc_enable,
 394         .disable = lp3972_dcdc_disable,
 395         .get_voltage_sel = lp3972_dcdc_get_voltage_sel,
 396         .set_voltage_sel = lp3972_dcdc_set_voltage_sel,
 397 };
 398
 399 static const struct regulator_desc regulators[] = {
 400         {
 401                 .name = "LDO1",
 402                 .id = LP3972_LDO1,
 403                 .ops = &lp3972_ldo_ops,
 404                 .n_voltages = ARRAY_SIZE(ldo1_voltage_map),
 405                 .volt_table = ldo1_voltage_map,
 406                 .type = REGULATOR_VOLTAGE,
 407                 .owner = THIS_MODULE,
 408         },
 409         {
 410                 .name = "LDO2",
 411                 .id = LP3972_LDO2,
 412                 .ops = &lp3972_ldo_ops,
 413                 .n_voltages = ARRAY_SIZE(ldo23_voltage_map),
 414                 .volt_table = ldo23_voltage_map,
 415                 .type = REGULATOR_VOLTAGE,
 416                 .owner = THIS_MODULE,
 417         },
 418         {
 419                 .name = "LDO3",
 420                 .id = LP3972_LDO3,
 421                 .ops = &lp3972_ldo_ops,
 422                 .n_voltages = ARRAY_SIZE(ldo23_voltage_map),
 423                 .volt_table = ldo23_voltage_map,
 424                 .type = REGULATOR_VOLTAGE,
 425                 .owner = THIS_MODULE,
 426         },
 427         {
 428                 .name = "LDO4",
 429                 .id = LP3972_LDO4,
 430                 .ops = &lp3972_ldo_ops,
 431                 .n_voltages = ARRAY_SIZE(ldo4_voltage_map),
 432                 .volt_table = ldo4_voltage_map,
 433                 .type = REGULATOR_VOLTAGE,
 434                 .owner = THIS_MODULE,
 435         },
 436         {
 437                 .name = "LDO5",
 438                 .id = LP3972_LDO5,
 439                 .ops = &lp3972_ldo_ops,
 440                 .n_voltages = ARRAY_SIZE(ldo5_voltage_map),
 441                 .volt_table = ldo5_voltage_map,
 442                 .type = REGULATOR_VOLTAGE,
 443                 .owner = THIS_MODULE,
 444         },
 445         {
 446                 .name = "DCDC1",
 447                 .id = LP3972_DCDC1,
 448                 .ops = &lp3972_dcdc_ops,
 449                 .n_voltages = ARRAY_SIZE(buck1_voltage_map),
 450                 .volt_table = buck1_voltage_map,
 451                 .type = REGULATOR_VOLTAGE,
 452                 .owner = THIS_MODULE,
 453         },
 454         {
 455                 .name = "DCDC2",
 456                 .id = LP3972_DCDC2,
 457                 .ops = &lp3972_dcdc_ops,
 458                 .n_voltages = ARRAY_SIZE(buck23_voltage_map),
 459                 .volt_table = buck23_voltage_map,
 460                 .type = REGULATOR_VOLTAGE,
 461                 .owner = THIS_MODULE,
 462         },
 463         {
 464                 .name = "DCDC3",
 465                 .id = LP3972_DCDC3,
 466                 .ops = &lp3972_dcdc_ops,
 467                 .n_voltages = ARRAY_SIZE(buck23_voltage_map),
 468                 .volt_table = buck23_voltage_map,
 469                 .type = REGULATOR_VOLTAGE,
 470                 .owner = THIS_MODULE,
 471         },
 472 };
 473
 474 static int setup_regulators(struct lp3972 *lp3972,
 475         struct lp3972_platform_data *pdata)
 476 {
 477         int i, err;
 478
 479         lp3972->num_regulators = pdata->num_regulators;
 480         lp3972->rdev = kcalloc(pdata->num_regulators,
 481                                 sizeof(struct regulator_dev *), GFP_KERNEL);
 482         if (!lp3972->rdev) {
 483                 err = -ENOMEM;
 484                 goto err_nomem;
 485         }
 486
 487         /* Instantiate the regulators */
 488         for (i = 0; i < pdata->num_regulators; i++) {
 489                 struct lp3972_regulator_subdev *reg = &pdata->regulators[i];
 490                 struct regulator_config config = { };
 491
 492                 config.dev = lp3972->dev;
 493                 config.init_data = reg->initdata;
 494                 config.driver_data = lp3972;
 495
 496                 lp3972->rdev[i] = regulator_register(&regulators[reg->id],
 497                                                      &config);
 498                 if (IS_ERR(lp3972->rdev[i])) {
 499                         err = PTR_ERR(lp3972->rdev[i]);
 500                         dev_err(lp3972->dev, "regulator init failed: %d\n",
 501                                 err);
 502                         goto error;
 503                 }
 504         }
 505
 506         return 0;
 507 error:
 508         while (--i >= 0)
 509                 regulator_unregister(lp3972->rdev[i]);
 510         kfree(lp3972->rdev);
 511         lp3972->rdev = NULL;
 512 err_nomem:
 513         return err;
 514 }
 515
 516 static int lp3972_i2c_probe(struct i2c_client *i2c,
 517                             const struct i2c_device_id *id)
 518 {
 519         struct lp3972 *lp3972;
 520         struct lp3972_platform_data *pdata = i2c->dev.platform_data;
 521         int ret;
 522         u16 val;
 523
 524         if (!pdata) {
 525                 dev_dbg(&i2c->dev, "No platform init data supplied\n");
 526                 return -ENODEV;
 527         }
 528
 529         lp3972 = kzalloc(sizeof(struct lp3972), GFP_KERNEL);
 530         if (!lp3972)
 531                 return -ENOMEM;
 532
 533         lp3972->i2c = i2c;
 534         lp3972->dev = &i2c->dev;
 535
 536         mutex_init(&lp3972->io_lock);
 537
 538         /* Detect LP3972 */
 539         ret = lp3972_i2c_read(i2c, LP3972_SYS_CONTROL1_REG, 1, &val);
 540         if (ret == 0 &&
 541                 (val & SYS_CONTROL1_INIT_MASK) != SYS_CONTROL1_INIT_VAL) {
 542                 ret = -ENODEV;
 543                 dev_err(&i2c->dev, "chip reported: val = 0x%x\n", val);
 544         }
 545         if (ret < 0) {
 546                 dev_err(&i2c->dev, "failed to detect device. ret = %d\n", ret);
 547                 goto err_detect;
 548         }
 549
 550         ret = setup_regulators(lp3972, pdata);
 551         if (ret < 0)
 552                 goto err_detect;
 553
 554         i2c_set_clientdata(i2c, lp3972);
 555         return 0;
 556
 557 err_detect:
 558         kfree(lp3972);
 559         return ret;
 560 }
 561
 562 static int lp3972_i2c_remove(struct i2c_client *i2c)
 563 {
 564         struct lp3972 *lp3972 = i2c_get_clientdata(i2c);
 565         int i;
 566
 567         for (i = 0; i < lp3972->num_regulators; i++)
 568                 regulator_unregister(lp3972->rdev[i]);
 569         kfree(lp3972->rdev);
 570         kfree(lp3972);
 571
 572         return 0;
 573 }
 574
 575 static const struct i2c_device_id lp3972_i2c_id[] = {
 576         { "lp3972", 0 },
 577         { }
 578 };
 579 MODULE_DEVICE_TABLE(i2c, lp3972_i2c_id);
 580
 581 static struct i2c_driver lp3972_i2c_driver = {
 582         .driver = {
 583                 .name = "lp3972",
 584                 .owner = THIS_MODULE,
 585         },
 586         .probe    = lp3972_i2c_probe,
 587         .remove   = lp3972_i2c_remove,
 588         .id_table = lp3972_i2c_id,
 589 };
 590
 591 static int __init lp3972_module_init(void)
 592 {
 593         return i2c_add_driver(&lp3972_i2c_driver);
 594 }
 595 subsys_initcall(lp3972_module_init);
 596
 597 static void __exit lp3972_module_exit(void)
 598 {
 599         i2c_del_driver(&lp3972_i2c_driver);
 600 }
 601 module_exit(lp3972_module_exit);
 602
 603 MODULE_LICENSE("GPL");
 604 MODULE_AUTHOR("Axel Lin <axel.lin@gmail.com>");
 605 MODULE_DESCRIPTION("LP3972 PMIC driver");