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/kernel.h>
  16 #include <linux/regulator/driver.h>
  17 #include <linux/regulator/lp3972.h>
  18 #include <linux/slab.h>
  19
  20 struct lp3972 {
  21         struct device *dev;
  22         struct mutex io_lock;
  23         struct i2c_client *i2c;
  24         int num_regulators;
  25         struct regulator_dev **rdev;
  26 };
  27
  28 /* LP3972 Control Registers */
  29 #define LP3972_SCR_REG          0x07
  30 #define LP3972_OVER1_REG        0x10
  31 #define LP3972_OVSR1_REG        0x11
  32 #define LP3972_OVER2_REG        0x12
  33 #define LP3972_OVSR2_REG        0x13
  34 #define LP3972_VCC1_REG         0x20
  35 #define LP3972_ADTV1_REG        0x23
  36 #define LP3972_ADTV2_REG        0x24
  37 #define LP3972_AVRC_REG         0x25
  38 #define LP3972_CDTC1_REG        0x26
  39 #define LP3972_CDTC2_REG        0x27
  40 #define LP3972_SDTV1_REG        0x29
  41 #define LP3972_SDTV2_REG        0x2A
  42 #define LP3972_MDTV1_REG        0x32
  43 #define LP3972_MDTV2_REG        0x33
  44 #define LP3972_L2VCR_REG        0x39
  45 #define LP3972_L34VCR_REG       0x3A
  46 #define LP3972_SCR1_REG         0x80
  47 #define LP3972_SCR2_REG         0x81
  48 #define LP3972_OEN3_REG         0x82
  49 #define LP3972_OSR3_REG         0x83
  50 #define LP3972_LOER4_REG        0x84
  51 #define LP3972_B2TV_REG         0x85
  52 #define LP3972_B3TV_REG         0x86
  53 #define LP3972_B32RC_REG        0x87
  54 #define LP3972_ISRA_REG         0x88
  55 #define LP3972_BCCR_REG         0x89
  56 #define LP3972_II1RR_REG        0x8E
  57 #define LP3972_II2RR_REG        0x8F
  58
  59 #define LP3972_SYS_CONTROL1_REG         LP3972_SCR1_REG
  60 /* System control register 1 initial value,
  61  * bits 5, 6 and 7 are EPROM programmable */
  62 #define SYS_CONTROL1_INIT_VAL           0x02
  63 #define SYS_CONTROL1_INIT_MASK          0x1F
  64
  65 #define LP3972_VOL_CHANGE_REG           LP3972_VCC1_REG
  66 #define LP3972_VOL_CHANGE_FLAG_GO       0x01
  67 #define LP3972_VOL_CHANGE_FLAG_MASK     0x03
  68
  69 /* LDO output enable mask */
  70 #define LP3972_OEN3_L1EN        BIT(0)
  71 #define LP3972_OVER2_LDO2_EN    BIT(2)
  72 #define LP3972_OVER2_LDO3_EN    BIT(3)
  73 #define LP3972_OVER2_LDO4_EN    BIT(4)
  74 #define LP3972_OVER1_S_EN       BIT(2)
  75
  76 static const int ldo1_voltage_map[] = {
  77         1700, 1725, 1750, 1775, 1800, 1825, 1850, 1875,
  78         1900, 1925, 1950, 1975, 2000,
  79 };
  80
  81 static const int ldo23_voltage_map[] = {
  82         1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500,
  83         2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300,
  84 };
  85
  86 static const int ldo4_voltage_map[] = {
  87         1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350,
  88         1400, 1500, 1800, 1900, 2500, 2800, 3000, 3300,
  89 };
  90
  91 static const int ldo5_voltage_map[] = {
  92            0,    0,    0,    0,    0,  850,  875,  900,
  93          925,  950,  975, 1000, 1025, 1050, 1075, 1100,
  94         1125, 1150, 1175, 1200, 1225, 1250, 1275, 1300,
  95         1325, 1350, 1375, 1400, 1425, 1450, 1475, 1500,
  96 };
  97
  98 static const int buck1_voltage_map[] = {
  99          725,  750,  775,  800,  825,  850,  875,  900,
 100          925,  950,  975, 1000, 1025, 1050, 1075, 1100,
 101         1125, 1150, 1175, 1200, 1225, 1250, 1275, 1300,
 102         1325, 1350, 1375, 1400, 1425, 1450, 1475, 1500,
 103 };
 104
 105 static const int buck23_voltage_map[] = {
 106            0,  800,  850,  900,  950, 1000, 1050, 1100,
 107         1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500,
 108         1550, 1600, 1650, 1700, 1800, 1900, 2500, 2800,
 109         3000, 3300,
 110 };
 111
 112 static const int *ldo_voltage_map[] = {
 113         ldo1_voltage_map,
 114         ldo23_voltage_map,
 115         ldo23_voltage_map,
 116         ldo4_voltage_map,
 117         ldo5_voltage_map,
 118 };
 119
 120 static const int *buck_voltage_map[] = {
 121         buck1_voltage_map,
 122         buck23_voltage_map,
 123         buck23_voltage_map,
 124 };
 125
 126 static const int ldo_output_enable_mask[] = {
 127         LP3972_OEN3_L1EN,
 128         LP3972_OVER2_LDO2_EN,
 129         LP3972_OVER2_LDO3_EN,
 130         LP3972_OVER2_LDO4_EN,
 131         LP3972_OVER1_S_EN,
 132 };
 133
 134 static const int ldo_output_enable_addr[] = {
 135         LP3972_OEN3_REG,
 136         LP3972_OVER2_REG,
 137         LP3972_OVER2_REG,
 138         LP3972_OVER2_REG,
 139         LP3972_OVER1_REG,
 140 };
 141
 142 static const int ldo_vol_ctl_addr[] = {
 143         LP3972_MDTV1_REG,
 144         LP3972_L2VCR_REG,
 145         LP3972_L34VCR_REG,
 146         LP3972_L34VCR_REG,
 147         LP3972_SDTV1_REG,
 148 };
 149
 150 static const int buck_vol_enable_addr[] = {
 151         LP3972_OVER1_REG,
 152         LP3972_OEN3_REG,
 153         LP3972_OEN3_REG,
 154 };
 155
 156 static const int buck_base_addr[] = {
 157         LP3972_ADTV1_REG,
 158         LP3972_B2TV_REG,
 159         LP3972_B3TV_REG,
 160 };
 161
 162 #define LP3972_LDO_VOL_VALUE_MAP(x) (ldo_voltage_map[x])
 163 #define LP3972_LDO_OUTPUT_ENABLE_MASK(x) (ldo_output_enable_mask[x])
 164 #define LP3972_LDO_OUTPUT_ENABLE_REG(x) (ldo_output_enable_addr[x])
 165
 166 /*      LDO voltage control registers shift:
 167         LP3972_LDO1 -> 0, LP3972_LDO2 -> 4
 168         LP3972_LDO3 -> 0, LP3972_LDO4 -> 4
 169         LP3972_LDO5 -> 0
 170 */
 171 #define LP3972_LDO_VOL_CONTR_SHIFT(x) (((x) & 1) << 2)
 172 #define LP3972_LDO_VOL_CONTR_REG(x) (ldo_vol_ctl_addr[x])
 173 #define LP3972_LDO_VOL_CHANGE_SHIFT(x) ((x) ? 4 : 6)
 174
 175 #define LP3972_LDO_VOL_MASK(x) (((x) % 4) ? 0x0f : 0x1f)
 176 #define LP3972_LDO_VOL_MIN_IDX(x) (((x) == 4) ? 0x05 : 0x00)
 177 #define LP3972_LDO_VOL_MAX_IDX(x) ((x) ? (((x) == 4) ? 0x1f : 0x0f) : 0x0c)
 178
 179 #define LP3972_BUCK_VOL_VALUE_MAP(x) (buck_voltage_map[x])
 180 #define LP3972_BUCK_VOL_ENABLE_REG(x) (buck_vol_enable_addr[x])
 181 #define LP3972_BUCK_VOL1_REG(x) (buck_base_addr[x])
 182 #define LP3972_BUCK_VOL_MASK 0x1f
 183 #define LP3972_BUCK_VOL_MIN_IDX(x) ((x) ? 0x01 : 0x00)
 184 #define LP3972_BUCK_VOL_MAX_IDX(x) ((x) ? 0x19 : 0x1f)
 185
 186 static int lp3972_i2c_read(struct i2c_client *i2c, char reg, int count,
 187         u16 *dest)
 188 {
 189         int ret;
 190
 191         if (count != 1)
 192                 return -EIO;
 193         ret = i2c_smbus_read_byte_data(i2c, reg);
 194         if (ret < 0)
 195                 return ret;
 196
 197         *dest = ret;
 198         return 0;
 199 }
 200
 201 static int lp3972_i2c_write(struct i2c_client *i2c, char reg, int count,
 202         const u16 *src)
 203 {
 204         if (count != 1)
 205                 return -EIO;
 206         return i2c_smbus_write_byte_data(i2c, reg, *src);
 207 }
 208
 209 static u8 lp3972_reg_read(struct lp3972 *lp3972, u8 reg)
 210 {
 211         u16 val = 0;
 212
 213         mutex_lock(&lp3972->io_lock);
 214
 215         lp3972_i2c_read(lp3972->i2c, reg, 1, &val);
 216
 217         dev_dbg(lp3972->dev, "reg read 0x%02x -> 0x%02x\n", (int)reg,
 218                 (unsigned)val & 0xff);
 219
 220         mutex_unlock(&lp3972->io_lock);
 221
 222         return val & 0xff;
 223 }
 224
 225 static int lp3972_set_bits(struct lp3972 *lp3972, u8 reg, u16 mask, u16 val)
 226 {
 227         u16 tmp;
 228         int ret;
 229
 230         mutex_lock(&lp3972->io_lock);
 231
 232         ret = lp3972_i2c_read(lp3972->i2c, reg, 1, &tmp);
 233         tmp = (tmp & ~mask) | val;
 234         if (ret == 0) {
 235                 ret = lp3972_i2c_write(lp3972->i2c, reg, 1, &tmp);
 236                 dev_dbg(lp3972->dev, "reg write 0x%02x -> 0x%02x\n", (int)reg,
 237                         (unsigned)val & 0xff);
 238         }
 239         mutex_unlock(&lp3972->io_lock);
 240
 241         return ret;
 242 }
 243
 244 static int lp3972_ldo_list_voltage(struct regulator_dev *dev, unsigned index)
 245 {
 246         int ldo = rdev_get_id(dev) - LP3972_LDO1;
 247         return 1000 * LP3972_LDO_VOL_VALUE_MAP(ldo)[index];
 248 }
 249
 250 static int lp3972_ldo_is_enabled(struct regulator_dev *dev)
 251 {
 252         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 253         int ldo = rdev_get_id(dev) - LP3972_LDO1;
 254         u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);
 255         u16 val;
 256
 257         val = lp3972_reg_read(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo));
 258         return !!(val & mask);
 259 }
 260
 261 static int lp3972_ldo_enable(struct regulator_dev *dev)
 262 {
 263         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 264         int ldo = rdev_get_id(dev) - LP3972_LDO1;
 265         u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);
 266
 267         return lp3972_set_bits(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo),
 268                                 mask, mask);
 269 }
 270
 271 static int lp3972_ldo_disable(struct regulator_dev *dev)
 272 {
 273         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 274         int ldo = rdev_get_id(dev) - LP3972_LDO1;
 275         u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);
 276
 277         return lp3972_set_bits(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo),
 278                                 mask, 0);
 279 }
 280
 281 static int lp3972_ldo_get_voltage(struct regulator_dev *dev)
 282 {
 283         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 284         int ldo = rdev_get_id(dev) - LP3972_LDO1;
 285         u16 mask = LP3972_LDO_VOL_MASK(ldo);
 286         u16 val, reg;
 287
 288         reg = lp3972_reg_read(lp3972, LP3972_LDO_VOL_CONTR_REG(ldo));
 289         val = (reg >> LP3972_LDO_VOL_CONTR_SHIFT(ldo)) & mask;
 290
 291         return 1000 * LP3972_LDO_VOL_VALUE_MAP(ldo)[val];
 292 }
 293
 294 static int lp3972_ldo_set_voltage(struct regulator_dev *dev,
 295                                   int min_uV, int max_uV,
 296                                   unsigned int *selector)
 297 {
 298         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 299         int ldo = rdev_get_id(dev) - LP3972_LDO1;
 300         int min_vol = min_uV / 1000, max_vol = max_uV / 1000;
 301         const int *vol_map = LP3972_LDO_VOL_VALUE_MAP(ldo);
 302         u16 val;
 303         int shift, ret;
 304
 305         if (min_vol < vol_map[LP3972_LDO_VOL_MIN_IDX(ldo)] ||
 306             min_vol > vol_map[LP3972_LDO_VOL_MAX_IDX(ldo)])
 307                 return -EINVAL;
 308
 309         for (val = LP3972_LDO_VOL_MIN_IDX(ldo);
 310                 val <= LP3972_LDO_VOL_MAX_IDX(ldo); val++)
 311                 if (vol_map[val] >= min_vol)
 312                         break;
 313
 314         if (val > LP3972_LDO_VOL_MAX_IDX(ldo) || vol_map[val] > max_vol)
 315                 return -EINVAL;
 316
 317         *selector = val;
 318
 319         shift = LP3972_LDO_VOL_CONTR_SHIFT(ldo);
 320         ret = lp3972_set_bits(lp3972, LP3972_LDO_VOL_CONTR_REG(ldo),
 321                 LP3972_LDO_VOL_MASK(ldo) << shift, val << shift);
 322
 323         if (ret)
 324                 return ret;
 325
 326         /*
 327          * LDO1 and LDO5 support voltage control by either target voltage1
 328          * or target voltage2 register.
 329          * We use target voltage1 register for LDO1 and LDO5 in this driver.
 330          * We need to update voltage change control register(0x20) to enable
 331          * LDO1 and LDO5 to change to their programmed target values.
 332          */
 333         switch (ldo) {
 334         case LP3972_LDO1:
 335         case LP3972_LDO5:
 336                 shift = LP3972_LDO_VOL_CHANGE_SHIFT(ldo);
 337                 ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
 338                         LP3972_VOL_CHANGE_FLAG_MASK << shift,
 339                         LP3972_VOL_CHANGE_FLAG_GO << shift);
 340                 if (ret)
 341                         return ret;
 342
 343                 ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
 344                         LP3972_VOL_CHANGE_FLAG_MASK << shift, 0);
 345                 break;
 346         }
 347
 348         return ret;
 349 }
 350
 351 static struct regulator_ops lp3972_ldo_ops = {
 352         .list_voltage = lp3972_ldo_list_voltage,
 353         .is_enabled = lp3972_ldo_is_enabled,
 354         .enable = lp3972_ldo_enable,
 355         .disable = lp3972_ldo_disable,
 356         .get_voltage = lp3972_ldo_get_voltage,
 357         .set_voltage = lp3972_ldo_set_voltage,
 358 };
 359
 360 static int lp3972_dcdc_list_voltage(struct regulator_dev *dev, unsigned index)
 361 {
 362         int buck = rdev_get_id(dev) - LP3972_DCDC1;
 363         return 1000 * buck_voltage_map[buck][index];
 364 }
 365
 366 static int lp3972_dcdc_is_enabled(struct regulator_dev *dev)
 367 {
 368         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 369         int buck = rdev_get_id(dev) - LP3972_DCDC1;
 370         u16 mask = 1 << (buck * 2);
 371         u16 val;
 372
 373         val = lp3972_reg_read(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck));
 374         return !!(val & mask);
 375 }
 376
 377 static int lp3972_dcdc_enable(struct regulator_dev *dev)
 378 {
 379         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 380         int buck = rdev_get_id(dev) - LP3972_DCDC1;
 381         u16 mask = 1 << (buck * 2);
 382         u16 val;
 383
 384         val = lp3972_set_bits(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck),
 385                                 mask, mask);
 386         return val;
 387 }
 388
 389 static int lp3972_dcdc_disable(struct regulator_dev *dev)
 390 {
 391         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 392         int buck = rdev_get_id(dev) - LP3972_DCDC1;
 393         u16 mask = 1 << (buck * 2);
 394         u16 val;
 395
 396         val = lp3972_set_bits(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck),
 397                                 mask, 0);
 398         return val;
 399 }
 400
 401 static int lp3972_dcdc_get_voltage(struct regulator_dev *dev)
 402 {
 403         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 404         int buck = rdev_get_id(dev) - LP3972_DCDC1;
 405         u16 reg;
 406         int val;
 407
 408         reg = lp3972_reg_read(lp3972, LP3972_BUCK_VOL1_REG(buck));
 409         reg &= LP3972_BUCK_VOL_MASK;
 410         if (reg <= LP3972_BUCK_VOL_MAX_IDX(buck))
 411                 val = 1000 * buck_voltage_map[buck][reg];
 412         else {
 413                 val = 0;
 414                 dev_warn(&dev->dev, "chip reported incorrect voltage value."
 415                                     " reg = %d\n", reg);
 416         }
 417
 418         return val;
 419 }
 420
 421 static int lp3972_dcdc_set_voltage(struct regulator_dev *dev,
 422                                    int min_uV, int max_uV,
 423                                    unsigned int *selector)
 424 {
 425         struct lp3972 *lp3972 = rdev_get_drvdata(dev);
 426         int buck = rdev_get_id(dev) - LP3972_DCDC1;
 427         int min_vol = min_uV / 1000, max_vol = max_uV / 1000;
 428         const int *vol_map = buck_voltage_map[buck];
 429         u16 val;
 430         int ret;
 431
 432         if (min_vol < vol_map[LP3972_BUCK_VOL_MIN_IDX(buck)] ||
 433             min_vol > vol_map[LP3972_BUCK_VOL_MAX_IDX(buck)])
 434                 return -EINVAL;
 435
 436         for (val = LP3972_BUCK_VOL_MIN_IDX(buck);
 437                 val <= LP3972_BUCK_VOL_MAX_IDX(buck); val++)
 438                 if (vol_map[val] >= min_vol)
 439                         break;
 440
 441         if (val > LP3972_BUCK_VOL_MAX_IDX(buck) ||
 442             vol_map[val] > max_vol)
 443                 return -EINVAL;
 444
 445         *selector = val;
 446
 447         ret = lp3972_set_bits(lp3972, LP3972_BUCK_VOL1_REG(buck),
 448                                 LP3972_BUCK_VOL_MASK, val);
 449         if (ret)
 450                 return ret;
 451
 452         if (buck != 0)
 453                 return ret;
 454
 455         ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
 456                 LP3972_VOL_CHANGE_FLAG_MASK, LP3972_VOL_CHANGE_FLAG_GO);
 457         if (ret)
 458                 return ret;
 459
 460         return lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
 461                                 LP3972_VOL_CHANGE_FLAG_MASK, 0);
 462 }
 463
 464 static struct regulator_ops lp3972_dcdc_ops = {
 465         .list_voltage = lp3972_dcdc_list_voltage,
 466         .is_enabled = lp3972_dcdc_is_enabled,
 467         .enable = lp3972_dcdc_enable,
 468         .disable = lp3972_dcdc_disable,
 469         .get_voltage = lp3972_dcdc_get_voltage,
 470         .set_voltage = lp3972_dcdc_set_voltage,
 471 };
 472
 473 static struct regulator_desc regulators[] = {
 474         {
 475                 .name = "LDO1",
 476                 .id = LP3972_LDO1,
 477                 .ops = &lp3972_ldo_ops,
 478                 .n_voltages = ARRAY_SIZE(ldo1_voltage_map),
 479                 .type = REGULATOR_VOLTAGE,
 480                 .owner = THIS_MODULE,
 481         },
 482         {
 483                 .name = "LDO2",
 484                 .id = LP3972_LDO2,
 485                 .ops = &lp3972_ldo_ops,
 486                 .n_voltages = ARRAY_SIZE(ldo23_voltage_map),
 487                 .type = REGULATOR_VOLTAGE,
 488                 .owner = THIS_MODULE,
 489         },
 490         {
 491                 .name = "LDO3",
 492                 .id = LP3972_LDO3,
 493                 .ops = &lp3972_ldo_ops,
 494                 .n_voltages = ARRAY_SIZE(ldo23_voltage_map),
 495                 .type = REGULATOR_VOLTAGE,
 496                 .owner = THIS_MODULE,
 497         },
 498         {
 499                 .name = "LDO4",
 500                 .id = LP3972_LDO4,
 501                 .ops = &lp3972_ldo_ops,
 502                 .n_voltages = ARRAY_SIZE(ldo4_voltage_map),
 503                 .type = REGULATOR_VOLTAGE,
 504                 .owner = THIS_MODULE,
 505         },
 506         {
 507                 .name = "LDO5",
 508                 .id = LP3972_LDO5,
 509                 .ops = &lp3972_ldo_ops,
 510                 .n_voltages = ARRAY_SIZE(ldo5_voltage_map),
 511                 .type = REGULATOR_VOLTAGE,
 512                 .owner = THIS_MODULE,
 513         },
 514         {
 515                 .name = "DCDC1",
 516                 .id = LP3972_DCDC1,
 517                 .ops = &lp3972_dcdc_ops,
 518                 .n_voltages = ARRAY_SIZE(buck1_voltage_map),
 519                 .type = REGULATOR_VOLTAGE,
 520                 .owner = THIS_MODULE,
 521         },
 522         {
 523                 .name = "DCDC2",
 524                 .id = LP3972_DCDC2,
 525                 .ops = &lp3972_dcdc_ops,
 526                 .n_voltages = ARRAY_SIZE(buck23_voltage_map),
 527                 .type = REGULATOR_VOLTAGE,
 528                 .owner = THIS_MODULE,
 529         },
 530         {
 531                 .name = "DCDC3",
 532                 .id = LP3972_DCDC3,
 533                 .ops = &lp3972_dcdc_ops,
 534                 .n_voltages = ARRAY_SIZE(buck23_voltage_map),
 535                 .type = REGULATOR_VOLTAGE,
 536                 .owner = THIS_MODULE,
 537         },
 538 };
 539
 540 static int __devinit setup_regulators(struct lp3972 *lp3972,
 541         struct lp3972_platform_data *pdata)
 542 {
 543         int i, err;
 544
 545         lp3972->num_regulators = pdata->num_regulators;
 546         lp3972->rdev = kcalloc(pdata->num_regulators,
 547                                 sizeof(struct regulator_dev *), GFP_KERNEL);
 548         if (!lp3972->rdev) {
 549                 err = -ENOMEM;
 550                 goto err_nomem;
 551         }
 552
 553         /* Instantiate the regulators */
 554         for (i = 0; i < pdata->num_regulators; i++) {
 555                 struct lp3972_regulator_subdev *reg = &pdata->regulators[i];
 556                 lp3972->rdev[i] = regulator_register(&regulators[reg->id],
 557                                         lp3972->dev, reg->initdata, lp3972);
 558
 559                 if (IS_ERR(lp3972->rdev[i])) {
 560                         err = PTR_ERR(lp3972->rdev[i]);
 561                         dev_err(lp3972->dev, "regulator init failed: %d\n",
 562                                 err);
 563                         goto error;
 564                 }
 565         }
 566
 567         return 0;
 568 error:
 569         while (--i >= 0)
 570                 regulator_unregister(lp3972->rdev[i]);
 571         kfree(lp3972->rdev);
 572         lp3972->rdev = NULL;
 573 err_nomem:
 574         return err;
 575 }
 576
 577 static int __devinit lp3972_i2c_probe(struct i2c_client *i2c,
 578                             const struct i2c_device_id *id)
 579 {
 580         struct lp3972 *lp3972;
 581         struct lp3972_platform_data *pdata = i2c->dev.platform_data;
 582         int ret;
 583         u16 val;
 584
 585         if (!pdata) {
 586                 dev_dbg(&i2c->dev, "No platform init data supplied\n");
 587                 return -ENODEV;
 588         }
 589
 590         lp3972 = kzalloc(sizeof(struct lp3972), GFP_KERNEL);
 591         if (!lp3972)
 592                 return -ENOMEM;
 593
 594         lp3972->i2c = i2c;
 595         lp3972->dev = &i2c->dev;
 596
 597         mutex_init(&lp3972->io_lock);
 598
 599         /* Detect LP3972 */
 600         ret = lp3972_i2c_read(i2c, LP3972_SYS_CONTROL1_REG, 1, &val);
 601         if (ret == 0 &&
 602                 (val & SYS_CONTROL1_INIT_MASK) != SYS_CONTROL1_INIT_VAL) {
 603                 ret = -ENODEV;
 604                 dev_err(&i2c->dev, "chip reported: val = 0x%x\n", val);
 605         }
 606         if (ret < 0) {
 607                 dev_err(&i2c->dev, "failed to detect device. ret = %d\n", ret);
 608                 goto err_detect;
 609         }
 610
 611         ret = setup_regulators(lp3972, pdata);
 612         if (ret < 0)
 613                 goto err_detect;
 614
 615         i2c_set_clientdata(i2c, lp3972);
 616         return 0;
 617
 618 err_detect:
 619         kfree(lp3972);
 620         return ret;
 621 }
 622
 623 static int __devexit lp3972_i2c_remove(struct i2c_client *i2c)
 624 {
 625         struct lp3972 *lp3972 = i2c_get_clientdata(i2c);
 626         int i;
 627
 628         for (i = 0; i < lp3972->num_regulators; i++)
 629                 regulator_unregister(lp3972->rdev[i]);
 630         kfree(lp3972->rdev);
 631         kfree(lp3972);
 632
 633         return 0;
 634 }
 635
 636 static const struct i2c_device_id lp3972_i2c_id[] = {
 637         { "lp3972", 0 },
 638         { }
 639 };
 640 MODULE_DEVICE_TABLE(i2c, lp3972_i2c_id);
 641
 642 static struct i2c_driver lp3972_i2c_driver = {
 643         .driver = {
 644                 .name = "lp3972",
 645                 .owner = THIS_MODULE,
 646         },
 647         .probe    = lp3972_i2c_probe,
 648         .remove   = __devexit_p(lp3972_i2c_remove),
 649         .id_table = lp3972_i2c_id,
 650 };
 651
 652 static int __init lp3972_module_init(void)
 653 {
 654         return i2c_add_driver(&lp3972_i2c_driver);
 655 }
 656 subsys_initcall(lp3972_module_init);
 657
 658 static void __exit lp3972_module_exit(void)
 659 {
 660         i2c_del_driver(&lp3972_i2c_driver);
 661 }
 662 module_exit(lp3972_module_exit);
 663
 664 MODULE_LICENSE("GPL");
 665 MODULE_AUTHOR("Axel Lin <axel.lin@gmail.com>");
 666 MODULE_DESCRIPTION("LP3972 PMIC driver");