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 int ldo1_voltage_map[] = {
  78         1700, 1725, 1750, 1775, 1800, 1825, 1850, 1875,
  79         1900, 1925, 1950, 1975, 2000,
  80 };
  81
  82 static const int ldo23_voltage_map[] = {
  83         1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500,
  84         2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300,
  85 };
  86
  87 static const int ldo4_voltage_map[] = {
  88         1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350,
  89         1400, 1500, 1800, 1900, 2500, 2800, 3000, 3300,
  90 };
  91
  92 static const int ldo5_voltage_map[] = {
  93            0,    0,    0,    0,    0,  850,  875,  900,
  94          925,  950,  975, 1000, 1025, 1050, 1075, 1100,
  95         1125, 1150, 1175, 1200, 1225, 1250, 1275, 1300,
  96         1325, 1350, 1375, 1400, 1425, 1450, 1475, 1500,
  97 };
  98
  99 static const int buck1_voltage_map[] = {
 100          725,  750,  775,  800,  825,  850,  875,  900,
 101          925,  950,  975, 1000, 1025, 1050, 1075, 1100,
 102         1125, 1150, 1175, 1200, 1225, 1250, 1275, 1300,
 103         1325, 1350, 1375, 1400, 1425, 1450, 1475, 1500,
 104 };
 105
 106 static const int buck23_voltage_map[] = {
 107            0,  800,  850,  900,  950, 1000, 1050, 1100,
 108         1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500,
 109         1550, 1600, 1650, 1700, 1800, 1900, 2500, 2800,
 110         3000, 3300,
 111 };
 112
 113 static const int *ldo_voltage_map[] = {
 114         ldo1_voltage_map,
 115         ldo23_voltage_map,
 116         ldo23_voltage_map,
 117         ldo4_voltage_map,
 118         ldo5_voltage_map,
 119 };
 120
 121 static const int *buck_voltage_map[] = {
 122         buck1_voltage_map,
 123         buck23_voltage_map,
 124         buck23_voltage_map,
 125 };
 126
 127 static const int ldo_output_enable_mask[] = {
 128         LP3972_OEN3_L1EN,
 129         LP3972_OVER2_LDO2_EN,
 130         LP3972_OVER2_LDO3_EN,
 131         LP3972_OVER2_LDO4_EN,
 132         LP3972_OVER1_S_EN,
 133 };
 134
 135 static const int ldo_output_enable_addr[] = {
 136         LP3972_OEN3_REG,
 137         LP3972_OVER2_REG,
 138         LP3972_OVER2_REG,
 139         LP3972_OVER2_REG,
 140         LP3972_OVER1_REG,
 141 };
 142
 143 static const int ldo_vol_ctl_addr[] = {
 144         LP3972_MDTV1_REG,
 145         LP3972_L2VCR_REG,
 146         LP3972_L34VCR_REG,
 147         LP3972_L34VCR_REG,
 148         LP3972_SDTV1_REG,
 149 };
 150
 151 static const int buck_vol_enable_addr[] = {
 152         LP3972_OVER1_REG,
 153         LP3972_OEN3_REG,
 154         LP3972_OEN3_REG,
 155 };
 156
 157 static const int buck_base_addr[] = {
 158         LP3972_ADTV1_REG,
 159         LP3972_B2TV_REG,
 160         LP3972_B3TV_REG,
 161 };
 162
 163 #define LP3972_LDO_VOL_VALUE_MAP(x) (ldo_voltage_map[x])
 164 #define LP3972_LDO_OUTPUT_ENABLE_MASK(x) (ldo_output_enable_mask[x])
 165 #define LP3972_LDO_OUTPUT_ENABLE_REG(x) (ldo_output_enable_addr[x])
 166
 167 /*      LDO voltage control registers shift:
 168         LP3972_LDO1 -> 0, LP3972_LDO2 -> 4
 169         LP3972_LDO3 -> 0, LP3972_LDO4 -> 4
 170         LP3972_LDO5 -> 0
 171 */
 172 #define LP3972_LDO_VOL_CONTR_SHIFT(x) (((x) & 1) << 2)
 173 #define LP3972_LDO_VOL_CONTR_REG(x) (ldo_vol_ctl_addr[x])
 174 #define LP3972_LDO_VOL_CHANGE_SHIFT(x) ((x) ? 4 : 6)
 175
 176 #define LP3972_LDO_VOL_MASK(x) (((x) % 4) ? 0x0f : 0x1f)
 177 #define LP3972_LDO_VOL_MIN_IDX(x) (((x) == 4) ? 0x05 : 0x00)
 178 #define LP3972_LDO_VOL_MAX_IDX(x) ((x) ? (((x) == 4) ? 0x1f : 0x0f) : 0x0c)
 179
 180 #define LP3972_BUCK_VOL_VALUE_MAP(x) (buck_voltage_map[x])
 181 #define LP3972_BUCK_VOL_ENABLE_REG(x) (buck_vol_enable_addr[x])
 182 #define LP3972_BUCK_VOL1_REG(x) (buck_base_addr[x])
 183 #define LP3972_BUCK_VOL_MASK 0x1f
 184 #define LP3972_BUCK_VOL_MIN_IDX(x) ((x) ? 0x01 : 0x00)
 185 #define LP3972_BUCK_VOL_MAX_IDX(x) ((x) ? 0x19 : 0x1f)
 186
 187 static int lp3972_i2c_read(struct i2c_client *i2c, char reg, int count,
 188         u16 *dest)
 189 {
 190         int ret;
 191
 192         if (count != 1)
 193                 return -EIO;
 194         ret = i2c_smbus_read_byte_data(i2c, reg);
 195         if (ret < 0)
 196                 return ret;
 197
 198         *dest = ret;
 199         return 0;
 200 }
 201
 202 static int lp3972_i2c_write(struct i2c_client *i2c, char reg, int count,
 203         const u16 *src)
 204 {
 205         if (count != 1)
 206                 return -EIO;
 207         return i2c_smbus_write_byte_data(i2c, reg, *src);
 208 }
 209
 210 static u8 lp3972_reg_read(struct lp3972 *lp3972, u8 reg)
 211 {
 212         u16 val = 0;
 213
 214         mutex_lock(&lp3972->io_lock);
 215
 216         lp3972_i2c_read(lp3972->i2c, reg, 1, &val);
 217
 218         dev_dbg(lp3972->dev, "reg read 0x%02x -> 0x%02x\n", (int)reg,
 219                 (unsigned)val & 0xff);
 220
 221         mutex_unlock(&lp3972->io_lock);
 222
 223         return val & 0xff;
 224 }
 225
 226 static int lp3972_set_bits(struct lp3972 *lp3972, u8 reg, u16 mask, u16 val)
 227 {
 228         u16 tmp;
 229         int ret;
 230
 231         mutex_lock(&lp3972->io_lock);
 232
 233         ret = lp3972_i2c_read(lp3972->i2c, reg, 1, &tmp);
 234         tmp = (tmp & ~mask) | val;
 235         if (ret == 0) {
 236                 ret = lp3972_i2c_write(lp3972->i2c, reg, 1, &tmp);
 237                 dev_dbg(lp3972->dev, "reg write 0x%02x -> 0x%02x\n", (int)reg,
 238                         (unsigned)val & 0xff);
 239         }
 240         mutex_unlock(&lp3972->io_lock);
 241
 242         return ret;
 243 }
 244
 245 static int lp3972_ldo_list_voltage(struct regulator_dev *dev, unsigned index)
 246 {
 247         int ldo = rdev_get_id(dev) - LP3972_LDO1;
 248         return 1000 * LP3972_LDO_VOL_VALUE_MAP(ldo)[index];
 249 }
 250
 251 static int lp3972_ldo_is_enabled(struct regulator_dev *dev)
 252 {
 253         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 254         int ldo = rdev_get_id(dev) - LP3972_LDO1;
 255         u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);
 256         u16 val;
 257
 258         val = lp3972_reg_read(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo));
 259         return !!(val & mask);
 260 }
 261
 262 static int lp3972_ldo_enable(struct regulator_dev *dev)
 263 {
 264         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 265         int ldo = rdev_get_id(dev) - LP3972_LDO1;
 266         u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);
 267
 268         return lp3972_set_bits(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo),
 269                                 mask, mask);
 270 }
 271
 272 static int lp3972_ldo_disable(struct regulator_dev *dev)
 273 {
 274         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 275         int ldo = rdev_get_id(dev) - LP3972_LDO1;
 276         u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);
 277
 278         return lp3972_set_bits(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo),
 279                                 mask, 0);
 280 }
 281
 282 static int lp3972_ldo_get_voltage(struct regulator_dev *dev)
 283 {
 284         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 285         int ldo = rdev_get_id(dev) - LP3972_LDO1;
 286         u16 mask = LP3972_LDO_VOL_MASK(ldo);
 287         u16 val, reg;
 288
 289         reg = lp3972_reg_read(lp3972, LP3972_LDO_VOL_CONTR_REG(ldo));
 290         val = (reg >> LP3972_LDO_VOL_CONTR_SHIFT(ldo)) & mask;
 291
 292         return 1000 * LP3972_LDO_VOL_VALUE_MAP(ldo)[val];
 293 }
 294
 295 static int lp3972_ldo_set_voltage(struct regulator_dev *dev,
 296                                   int min_uV, int max_uV,
 297                                   unsigned int *selector)
 298 {
 299         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 300         int ldo = rdev_get_id(dev) - LP3972_LDO1;
 301         int min_vol = min_uV / 1000, max_vol = max_uV / 1000;
 302         const int *vol_map = LP3972_LDO_VOL_VALUE_MAP(ldo);
 303         u16 val;
 304         int shift, ret;
 305
 306         if (min_vol < vol_map[LP3972_LDO_VOL_MIN_IDX(ldo)] ||
 307             min_vol > vol_map[LP3972_LDO_VOL_MAX_IDX(ldo)])
 308                 return -EINVAL;
 309
 310         for (val = LP3972_LDO_VOL_MIN_IDX(ldo);
 311                 val <= LP3972_LDO_VOL_MAX_IDX(ldo); val++)
 312                 if (vol_map[val] >= min_vol)
 313                         break;
 314
 315         if (val > LP3972_LDO_VOL_MAX_IDX(ldo) || vol_map[val] > max_vol)
 316                 return -EINVAL;
 317
 318         *selector = val;
 319
 320         shift = LP3972_LDO_VOL_CONTR_SHIFT(ldo);
 321         ret = lp3972_set_bits(lp3972, LP3972_LDO_VOL_CONTR_REG(ldo),
 322                 LP3972_LDO_VOL_MASK(ldo) << shift, val << shift);
 323
 324         if (ret)
 325                 return ret;
 326
 327         /*
 328          * LDO1 and LDO5 support voltage control by either target voltage1
 329          * or target voltage2 register.
 330          * We use target voltage1 register for LDO1 and LDO5 in this driver.
 331          * We need to update voltage change control register(0x20) to enable
 332          * LDO1 and LDO5 to change to their programmed target values.
 333          */
 334         switch (ldo) {
 335         case LP3972_LDO1:
 336         case LP3972_LDO5:
 337                 shift = LP3972_LDO_VOL_CHANGE_SHIFT(ldo);
 338                 ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
 339                         LP3972_VOL_CHANGE_FLAG_MASK << shift,
 340                         LP3972_VOL_CHANGE_FLAG_GO << shift);
 341                 if (ret)
 342                         return ret;
 343
 344                 ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
 345                         LP3972_VOL_CHANGE_FLAG_MASK << shift, 0);
 346                 break;
 347         }
 348
 349         return ret;
 350 }
 351
 352 static struct regulator_ops lp3972_ldo_ops = {
 353         .list_voltage = lp3972_ldo_list_voltage,
 354         .is_enabled = lp3972_ldo_is_enabled,
 355         .enable = lp3972_ldo_enable,
 356         .disable = lp3972_ldo_disable,
 357         .get_voltage = lp3972_ldo_get_voltage,
 358         .set_voltage = lp3972_ldo_set_voltage,
 359 };
 360
 361 static int lp3972_dcdc_list_voltage(struct regulator_dev *dev, unsigned index)
 362 {
 363         int buck = rdev_get_id(dev) - LP3972_DCDC1;
 364         return 1000 * buck_voltage_map[buck][index];
 365 }
 366
 367 static int lp3972_dcdc_is_enabled(struct regulator_dev *dev)
 368 {
 369         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 370         int buck = rdev_get_id(dev) - LP3972_DCDC1;
 371         u16 mask = 1 << (buck * 2);
 372         u16 val;
 373
 374         val = lp3972_reg_read(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck));
 375         return !!(val & mask);
 376 }
 377
 378 static int lp3972_dcdc_enable(struct regulator_dev *dev)
 379 {
 380         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 381         int buck = rdev_get_id(dev) - LP3972_DCDC1;
 382         u16 mask = 1 << (buck * 2);
 383         u16 val;
 384
 385         val = lp3972_set_bits(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck),
 386                                 mask, mask);
 387         return val;
 388 }
 389
 390 static int lp3972_dcdc_disable(struct regulator_dev *dev)
 391 {
 392         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 393         int buck = rdev_get_id(dev) - LP3972_DCDC1;
 394         u16 mask = 1 << (buck * 2);
 395         u16 val;
 396
 397         val = lp3972_set_bits(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck),
 398                                 mask, 0);
 399         return val;
 400 }
 401
 402 static int lp3972_dcdc_get_voltage(struct regulator_dev *dev)
 403 {
 404         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 405         int buck = rdev_get_id(dev) - LP3972_DCDC1;
 406         u16 reg;
 407         int val;
 408
 409         reg = lp3972_reg_read(lp3972, LP3972_BUCK_VOL1_REG(buck));
 410         reg &= LP3972_BUCK_VOL_MASK;
 411         if (reg <= LP3972_BUCK_VOL_MAX_IDX(buck))
 412                 val = 1000 * buck_voltage_map[buck][reg];
 413         else {
 414                 val = 0;
 415                 dev_warn(&dev->dev, "chip reported incorrect voltage value."
 416                                     " reg = %d\n", reg);
 417         }
 418
 419         return val;
 420 }
 421
 422 static int lp3972_dcdc_set_voltage(struct regulator_dev *dev,
 423                                    int min_uV, int max_uV,
 424                                    unsigned int *selector)
 425 {
 426         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 427         int buck = rdev_get_id(dev) - LP3972_DCDC1;
 428         int min_vol = min_uV / 1000, max_vol = max_uV / 1000;
 429         const int *vol_map = buck_voltage_map[buck];
 430         u16 val;
 431         int ret;
 432
 433         if (min_vol < vol_map[LP3972_BUCK_VOL_MIN_IDX(buck)] ||
 434             min_vol > vol_map[LP3972_BUCK_VOL_MAX_IDX(buck)])
 435                 return -EINVAL;
 436
 437         for (val = LP3972_BUCK_VOL_MIN_IDX(buck);
 438                 val <= LP3972_BUCK_VOL_MAX_IDX(buck); val++)
 439                 if (vol_map[val] >= min_vol)
 440                         break;
 441
 442         if (val > LP3972_BUCK_VOL_MAX_IDX(buck) ||
 443             vol_map[val] > max_vol)
 444                 return -EINVAL;
 445
 446         *selector = val;
 447
 448         ret = lp3972_set_bits(lp3972, LP3972_BUCK_VOL1_REG(buck),
 449                                 LP3972_BUCK_VOL_MASK, val);
 450         if (ret)
 451                 return ret;
 452
 453         if (buck != 0)
 454                 return ret;
 455
 456         ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
 457                 LP3972_VOL_CHANGE_FLAG_MASK, LP3972_VOL_CHANGE_FLAG_GO);
 458         if (ret)
 459                 return ret;
 460
 461         return lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
 462                                 LP3972_VOL_CHANGE_FLAG_MASK, 0);
 463 }
 464
 465 static struct regulator_ops lp3972_dcdc_ops = {
 466         .list_voltage = lp3972_dcdc_list_voltage,
 467         .is_enabled = lp3972_dcdc_is_enabled,
 468         .enable = lp3972_dcdc_enable,
 469         .disable = lp3972_dcdc_disable,
 470         .get_voltage = lp3972_dcdc_get_voltage,
 471         .set_voltage = lp3972_dcdc_set_voltage,
 472 };
 473
 474 static struct regulator_desc regulators[] = {
 475         {
 476                 .name = "LDO1",
 477                 .id = LP3972_LDO1,
 478                 .ops = &lp3972_ldo_ops,
 479                 .n_voltages = ARRAY_SIZE(ldo1_voltage_map),
 480                 .type = REGULATOR_VOLTAGE,
 481                 .owner = THIS_MODULE,
 482         },
 483         {
 484                 .name = "LDO2",
 485                 .id = LP3972_LDO2,
 486                 .ops = &lp3972_ldo_ops,
 487                 .n_voltages = ARRAY_SIZE(ldo23_voltage_map),
 488                 .type = REGULATOR_VOLTAGE,
 489                 .owner = THIS_MODULE,
 490         },
 491         {
 492                 .name = "LDO3",
 493                 .id = LP3972_LDO3,
 494                 .ops = &lp3972_ldo_ops,
 495                 .n_voltages = ARRAY_SIZE(ldo23_voltage_map),
 496                 .type = REGULATOR_VOLTAGE,
 497                 .owner = THIS_MODULE,
 498         },
 499         {
 500                 .name = "LDO4",
 501                 .id = LP3972_LDO4,
 502                 .ops = &lp3972_ldo_ops,
 503                 .n_voltages = ARRAY_SIZE(ldo4_voltage_map),
 504                 .type = REGULATOR_VOLTAGE,
 505                 .owner = THIS_MODULE,
 506         },
 507         {
 508                 .name = "LDO5",
 509                 .id = LP3972_LDO5,
 510                 .ops = &lp3972_ldo_ops,
 511                 .n_voltages = ARRAY_SIZE(ldo5_voltage_map),
 512                 .type = REGULATOR_VOLTAGE,
 513                 .owner = THIS_MODULE,
 514         },
 515         {
 516                 .name = "DCDC1",
 517                 .id = LP3972_DCDC1,
 518                 .ops = &lp3972_dcdc_ops,
 519                 .n_voltages = ARRAY_SIZE(buck1_voltage_map),
 520                 .type = REGULATOR_VOLTAGE,
 521                 .owner = THIS_MODULE,
 522         },
 523         {
 524                 .name = "DCDC2",
 525                 .id = LP3972_DCDC2,
 526                 .ops = &lp3972_dcdc_ops,
 527                 .n_voltages = ARRAY_SIZE(buck23_voltage_map),
 528                 .type = REGULATOR_VOLTAGE,
 529                 .owner = THIS_MODULE,
 530         },
 531         {
 532                 .name = "DCDC3",
 533                 .id = LP3972_DCDC3,
 534                 .ops = &lp3972_dcdc_ops,
 535                 .n_voltages = ARRAY_SIZE(buck23_voltage_map),
 536                 .type = REGULATOR_VOLTAGE,
 537                 .owner = THIS_MODULE,
 538         },
 539 };
 540
 541 static int __devinit setup_regulators(struct lp3972 *lp3972,
 542         struct lp3972_platform_data *pdata)
 543 {
 544         int i, err;
 545
 546         lp3972->num_regulators = pdata->num_regulators;
 547         lp3972->rdev = kcalloc(pdata->num_regulators,
 548                                 sizeof(struct regulator_dev *), GFP_KERNEL);
 549         if (!lp3972->rdev) {
 550                 err = -ENOMEM;
 551                 goto err_nomem;
 552         }
 553
 554         /* Instantiate the regulators */
 555         for (i = 0; i < pdata->num_regulators; i++) {
 556                 struct lp3972_regulator_subdev *reg = &pdata->regulators[i];
 557                 lp3972->rdev[i] = regulator_register(&regulators[reg->id],
 558                                 lp3972->dev, reg->initdata, lp3972, NULL);
 559
 560                 if (IS_ERR(lp3972->rdev[i])) {
 561                         err = PTR_ERR(lp3972->rdev[i]);
 562                         dev_err(lp3972->dev, "regulator init failed: %d\n",
 563                                 err);
 564                         goto error;
 565                 }
 566         }
 567
 568         return 0;
 569 error:
 570         while (--i >= 0)
 571                 regulator_unregister(lp3972->rdev[i]);
 572         kfree(lp3972->rdev);
 573         lp3972->rdev = NULL;
 574 err_nomem:
 575         return err;
 576 }
 577
 578 static int __devinit lp3972_i2c_probe(struct i2c_client *i2c,
 579                             const struct i2c_device_id *id)
 580 {
 581         struct lp3972 *lp3972;
 582         struct lp3972_platform_data *pdata = i2c->dev.platform_data;
 583         int ret;
 584         u16 val;
 585
 586         if (!pdata) {
 587                 dev_dbg(&i2c->dev, "No platform init data supplied\n");
 588                 return -ENODEV;
 589         }
 590
 591         lp3972 = kzalloc(sizeof(struct lp3972), GFP_KERNEL);
 592         if (!lp3972)
 593                 return -ENOMEM;
 594
 595         lp3972->i2c = i2c;
 596         lp3972->dev = &i2c->dev;
 597
 598         mutex_init(&lp3972->io_lock);
 599
 600         /* Detect LP3972 */
 601         ret = lp3972_i2c_read(i2c, LP3972_SYS_CONTROL1_REG, 1, &val);
 602         if (ret == 0 &&
 603                 (val & SYS_CONTROL1_INIT_MASK) != SYS_CONTROL1_INIT_VAL) {
 604                 ret = -ENODEV;
 605                 dev_err(&i2c->dev, "chip reported: val = 0x%x\n", val);
 606         }
 607         if (ret < 0) {
 608                 dev_err(&i2c->dev, "failed to detect device. ret = %d\n", ret);
 609                 goto err_detect;
 610         }
 611
 612         ret = setup_regulators(lp3972, pdata);
 613         if (ret < 0)
 614                 goto err_detect;
 615
 616         i2c_set_clientdata(i2c, lp3972);
 617         return 0;
 618
 619 err_detect:
 620         kfree(lp3972);
 621         return ret;
 622 }
 623
 624 static int __devexit lp3972_i2c_remove(struct i2c_client *i2c)
 625 {
 626         struct lp3972 *lp3972 = i2c_get_clientdata(i2c);
 627         int i;
 628
 629         for (i = 0; i < lp3972->num_regulators; i++)
 630                 regulator_unregister(lp3972->rdev[i]);
 631         kfree(lp3972->rdev);
 632         kfree(lp3972);
 633
 634         return 0;
 635 }
 636
 637 static const struct i2c_device_id lp3972_i2c_id[] = {
 638         { "lp3972", 0 },
 639         { }
 640 };
 641 MODULE_DEVICE_TABLE(i2c, lp3972_i2c_id);
 642
 643 static struct i2c_driver lp3972_i2c_driver = {
 644         .driver = {
 645                 .name = "lp3972",
 646                 .owner = THIS_MODULE,
 647         },
 648         .probe    = lp3972_i2c_probe,
 649         .remove   = __devexit_p(lp3972_i2c_remove),
 650         .id_table = lp3972_i2c_id,
 651 };
 652
 653 static int __init lp3972_module_init(void)
 654 {
 655         return i2c_add_driver(&lp3972_i2c_driver);
 656 }
 657 subsys_initcall(lp3972_module_init);
 658
 659 static void __exit lp3972_module_exit(void)
 660 {
 661         i2c_del_driver(&lp3972_i2c_driver);
 662 }
 663 module_exit(lp3972_module_exit);
 664
 665 MODULE_LICENSE("GPL");
 666 MODULE_AUTHOR("Axel Lin <axel.lin@gmail.com>");
 667 MODULE_DESCRIPTION("LP3972 PMIC driver");