drivers/regulator/ab3100.c

   1 /*
   2  * drivers/regulator/ab3100.c
   3  *
   4  * Copyright (C) 2008-2009 ST-Ericsson AB
   5  * License terms: GNU General Public License (GPL) version 2
   6  * Low-level control of the AB3100 IC Low Dropout (LDO)
   7  * regulators, external regulator and buck converter
   8  * Author: Mattias Wallin <mattias.wallin@stericsson.com>
   9  * Author: Linus Walleij <linus.walleij@stericsson.com>
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/kernel.h>
  14 #include <linux/init.h>
  15 #include <linux/err.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/regulator/driver.h>
  18 #include <linux/mfd/abx500.h>
  19
  20 /* LDO registers and some handy masking definitions for AB3100 */
  21 #define AB3100_LDO_A            0x40
  22 #define AB3100_LDO_C            0x41
  23 #define AB3100_LDO_D            0x42
  24 #define AB3100_LDO_E            0x43
  25 #define AB3100_LDO_E_SLEEP      0x44
  26 #define AB3100_LDO_F            0x45
  27 #define AB3100_LDO_G            0x46
  28 #define AB3100_LDO_H            0x47
  29 #define AB3100_LDO_H_SLEEP_MODE 0
  30 #define AB3100_LDO_H_SLEEP_EN   2
  31 #define AB3100_LDO_ON           4
  32 #define AB3100_LDO_H_VSEL_AC    5
  33 #define AB3100_LDO_K            0x48
  34 #define AB3100_LDO_EXT          0x49
  35 #define AB3100_BUCK             0x4A
  36 #define AB3100_BUCK_SLEEP       0x4B
  37 #define AB3100_REG_ON_MASK      0x10
  38
  39 /**
  40  * struct ab3100_regulator
  41  * A struct passed around the individual regulator functions
  42  * @platform_device: platform device holding this regulator
  43  * @dev: handle to the device
  44  * @plfdata: AB3100 platform data passed in at probe time
  45  * @regreg: regulator register number in the AB3100
  46  */
  47 struct ab3100_regulator {
  48         struct regulator_dev *rdev;
  49         struct device *dev;
  50         struct ab3100_platform_data *plfdata;
  51         u8 regreg;
  52 };
  53
  54 /* The order in which registers are initialized */
  55 static const u8 ab3100_reg_init_order[AB3100_NUM_REGULATORS+2] = {
  56         AB3100_LDO_A,
  57         AB3100_LDO_C,
  58         AB3100_LDO_E,
  59         AB3100_LDO_E_SLEEP,
  60         AB3100_LDO_F,
  61         AB3100_LDO_G,
  62         AB3100_LDO_H,
  63         AB3100_LDO_K,
  64         AB3100_LDO_EXT,
  65         AB3100_BUCK,
  66         AB3100_BUCK_SLEEP,
  67         AB3100_LDO_D,
  68 };
  69
  70 /* Preset (hardware defined) voltages for these regulators */
  71 #define LDO_A_VOLTAGE 2750000
  72 #define LDO_C_VOLTAGE 2650000
  73 #define LDO_D_VOLTAGE 2650000
  74
  75 static const unsigned int ldo_e_buck_typ_voltages[] = {
  76         1800000,
  77         1400000,
  78         1300000,
  79         1200000,
  80         1100000,
  81         1050000,
  82         900000,
  83 };
  84
  85 static const unsigned int ldo_f_typ_voltages[] = {
  86         1800000,
  87         1400000,
  88         1300000,
  89         1200000,
  90         1100000,
  91         1050000,
  92         2500000,
  93         2650000,
  94 };
  95
  96 static const unsigned int ldo_g_typ_voltages[] = {
  97         2850000,
  98         2750000,
  99         1800000,
 100         1500000,
 101 };
 102
 103 static const unsigned int ldo_h_typ_voltages[] = {
 104         2750000,
 105         1800000,
 106         1500000,
 107         1200000,
 108 };
 109
 110 static const unsigned int ldo_k_typ_voltages[] = {
 111         2750000,
 112         1800000,
 113 };
 114
 115
 116 /* The regulator devices */
 117 static struct ab3100_regulator
 118 ab3100_regulators[AB3100_NUM_REGULATORS] = {
 119         {
 120                 .regreg = AB3100_LDO_A,
 121         },
 122         {
 123                 .regreg = AB3100_LDO_C,
 124         },
 125         {
 126                 .regreg = AB3100_LDO_D,
 127         },
 128         {
 129                 .regreg = AB3100_LDO_E,
 130         },
 131         {
 132                 .regreg = AB3100_LDO_F,
 133         },
 134         {
 135                 .regreg = AB3100_LDO_G,
 136         },
 137         {
 138                 .regreg = AB3100_LDO_H,
 139         },
 140         {
 141                 .regreg = AB3100_LDO_K,
 142         },
 143         {
 144                 .regreg = AB3100_LDO_EXT,
 145                 /* No voltages for the external regulator */
 146         },
 147         {
 148                 .regreg = AB3100_BUCK,
 149         },
 150 };
 151
 152 /*
 153  * General functions for enable, disable and is_enabled used for
 154  * LDO: A,C,E,F,G,H,K,EXT and BUCK
 155  */
 156 static int ab3100_enable_regulator(struct regulator_dev *reg)
 157 {
 158         struct ab3100_regulator *abreg = rdev_get_drvdata(reg);
 159         int err;
 160         u8 regval;
 161
 162         err = abx500_get_register_interruptible(abreg->dev, 0, abreg->regreg,
 163                                                 &regval);
 164         if (err) {
 165                 dev_warn(&reg->dev, "failed to get regid %d value\n",
 166                          abreg->regreg);
 167                 return err;
 168         }
 169
 170         /* The regulator is already on, no reason to go further */
 171         if (regval & AB3100_REG_ON_MASK)
 172                 return 0;
 173
 174         regval |= AB3100_REG_ON_MASK;
 175
 176         err = abx500_set_register_interruptible(abreg->dev, 0, abreg->regreg,
 177                                                 regval);
 178         if (err) {
 179                 dev_warn(&reg->dev, "failed to set regid %d value\n",
 180                          abreg->regreg);
 181                 return err;
 182         }
 183
 184         return 0;
 185 }
 186
 187 static int ab3100_disable_regulator(struct regulator_dev *reg)
 188 {
 189         struct ab3100_regulator *abreg = rdev_get_drvdata(reg);
 190         int err;
 191         u8 regval;
 192
 193         /*
 194          * LDO D is a special regulator. When it is disabled, the entire
 195          * system is shut down. So this is handled specially.
 196          */
 197         pr_info("Called ab3100_disable_regulator\n");
 198         if (abreg->regreg == AB3100_LDO_D) {
 199                 dev_info(&reg->dev, "disabling LDO D - shut down system\n");
 200                 /* Setting LDO D to 0x00 cuts the power to the SoC */
 201                 return abx500_set_register_interruptible(abreg->dev, 0,
 202                                                          AB3100_LDO_D, 0x00U);
 203         }
 204
 205         /*
 206          * All other regulators are handled here
 207          */
 208         err = abx500_get_register_interruptible(abreg->dev, 0, abreg->regreg,
 209                                                 &regval);
 210         if (err) {
 211                 dev_err(&reg->dev, "unable to get register 0x%x\n",
 212                         abreg->regreg);
 213                 return err;
 214         }
 215         regval &= ~AB3100_REG_ON_MASK;
 216         return abx500_set_register_interruptible(abreg->dev, 0, abreg->regreg,
 217                                                  regval);
 218 }
 219
 220 static int ab3100_is_enabled_regulator(struct regulator_dev *reg)
 221 {
 222         struct ab3100_regulator *abreg = rdev_get_drvdata(reg);
 223         u8 regval;
 224         int err;
 225
 226         err = abx500_get_register_interruptible(abreg->dev, 0, abreg->regreg,
 227                                                 &regval);
 228         if (err) {
 229                 dev_err(&reg->dev, "unable to get register 0x%x\n",
 230                         abreg->regreg);
 231                 return err;
 232         }
 233
 234         return regval & AB3100_REG_ON_MASK;
 235 }
 236
 237 static int ab3100_get_voltage_regulator(struct regulator_dev *reg)
 238 {
 239         struct ab3100_regulator *abreg = rdev_get_drvdata(reg);
 240         u8 regval;
 241         int err;
 242
 243         /*
 244          * For variable types, read out setting and index into
 245          * supplied voltage list.
 246          */
 247         err = abx500_get_register_interruptible(abreg->dev, 0,
 248                                                 abreg->regreg, &regval);
 249         if (err) {
 250                 dev_warn(&reg->dev,
 251                          "failed to get regulator value in register %02x\n",
 252                          abreg->regreg);
 253                 return err;
 254         }
 255
 256         /* The 3 highest bits index voltages */
 257         regval &= 0xE0;
 258         regval >>= 5;
 259
 260         if (regval >= reg->desc->n_voltages) {
 261                 dev_err(&reg->dev,
 262                         "regulator register %02x contains an illegal voltage setting\n",
 263                         abreg->regreg);
 264                 return -EINVAL;
 265         }
 266
 267         return reg->desc->volt_table[regval];
 268 }
 269
 270 static int ab3100_set_voltage_regulator_sel(struct regulator_dev *reg,
 271                                             unsigned selector)
 272 {
 273         struct ab3100_regulator *abreg = rdev_get_drvdata(reg);
 274         u8 regval;
 275         int err;
 276
 277         err = abx500_get_register_interruptible(abreg->dev, 0,
 278                                                 abreg->regreg, &regval);
 279         if (err) {
 280                 dev_warn(&reg->dev,
 281                          "failed to get regulator register %02x\n",
 282                          abreg->regreg);
 283                 return err;
 284         }
 285
 286         /* The highest three bits control the variable regulators */
 287         regval &= ~0xE0;
 288         regval |= (selector << 5);
 289
 290         err = abx500_set_register_interruptible(abreg->dev, 0,
 291                                                 abreg->regreg, regval);
 292         if (err)
 293                 dev_warn(&reg->dev, "failed to set regulator register %02x\n",
 294                         abreg->regreg);
 295
 296         return err;
 297 }
 298
 299 static int ab3100_set_suspend_voltage_regulator(struct regulator_dev *reg,
 300                                                 int uV)
 301 {
 302         struct ab3100_regulator *abreg = rdev_get_drvdata(reg);
 303         u8 regval;
 304         int err;
 305         int bestindex;
 306         u8 targetreg;
 307
 308         if (abreg->regreg == AB3100_LDO_E)
 309                 targetreg = AB3100_LDO_E_SLEEP;
 310         else if (abreg->regreg == AB3100_BUCK)
 311                 targetreg = AB3100_BUCK_SLEEP;
 312         else
 313                 return -EINVAL;
 314
 315         /* LDO E and BUCK have special suspend voltages you can set */
 316         bestindex = regulator_map_voltage_iterate(reg, uV, uV);
 317
 318         err = abx500_get_register_interruptible(abreg->dev, 0,
 319                                                 targetreg, &regval);
 320         if (err) {
 321                 dev_warn(&reg->dev,
 322                          "failed to get regulator register %02x\n",
 323                          targetreg);
 324                 return err;
 325         }
 326
 327         /* The highest three bits control the variable regulators */
 328         regval &= ~0xE0;
 329         regval |= (bestindex << 5);
 330
 331         err = abx500_set_register_interruptible(abreg->dev, 0,
 332                                                 targetreg, regval);
 333         if (err)
 334                 dev_warn(&reg->dev, "failed to set regulator register %02x\n",
 335                         abreg->regreg);
 336
 337         return err;
 338 }
 339
 340 /*
 341  * The external regulator can just define a fixed voltage.
 342  */
 343 static int ab3100_get_voltage_regulator_external(struct regulator_dev *reg)
 344 {
 345         struct ab3100_regulator *abreg = rdev_get_drvdata(reg);
 346
 347         return abreg->plfdata->external_voltage;
 348 }
 349
 350 static int ab3100_get_fixed_voltage_regulator(struct regulator_dev *reg)
 351 {
 352         return reg->desc->min_uV;
 353 }
 354
 355 static struct regulator_ops regulator_ops_fixed = {
 356         .list_voltage = regulator_list_voltage_linear,
 357         .enable      = ab3100_enable_regulator,
 358         .disable     = ab3100_disable_regulator,
 359         .is_enabled  = ab3100_is_enabled_regulator,
 360         .get_voltage = ab3100_get_fixed_voltage_regulator,
 361 };
 362
 363 static struct regulator_ops regulator_ops_variable = {
 364         .enable      = ab3100_enable_regulator,
 365         .disable     = ab3100_disable_regulator,
 366         .is_enabled  = ab3100_is_enabled_regulator,
 367         .get_voltage = ab3100_get_voltage_regulator,
 368         .set_voltage_sel = ab3100_set_voltage_regulator_sel,
 369         .list_voltage = regulator_list_voltage_table,
 370 };
 371
 372 static struct regulator_ops regulator_ops_variable_sleepable = {
 373         .enable      = ab3100_enable_regulator,
 374         .disable     = ab3100_disable_regulator,
 375         .is_enabled  = ab3100_is_enabled_regulator,
 376         .get_voltage = ab3100_get_voltage_regulator,
 377         .set_voltage_sel = ab3100_set_voltage_regulator_sel,
 378         .set_suspend_voltage = ab3100_set_suspend_voltage_regulator,
 379         .list_voltage = regulator_list_voltage_table,
 380 };
 381
 382 /*
 383  * LDO EXT is an external regulator so it is really
 384  * not possible to set any voltage locally here, AB3100
 385  * is an on/off switch plain an simple. The external
 386  * voltage is defined in the board set-up if any.
 387  */
 388 static struct regulator_ops regulator_ops_external = {
 389         .enable      = ab3100_enable_regulator,
 390         .disable     = ab3100_disable_regulator,
 391         .is_enabled  = ab3100_is_enabled_regulator,
 392         .get_voltage = ab3100_get_voltage_regulator_external,
 393 };
 394
 395 static struct regulator_desc
 396 ab3100_regulator_desc[AB3100_NUM_REGULATORS] = {
 397         {
 398                 .name = "LDO_A",
 399                 .id   = AB3100_LDO_A,
 400                 .ops  = &regulator_ops_fixed,
 401                 .n_voltages = 1,
 402                 .type = REGULATOR_VOLTAGE,
 403                 .owner = THIS_MODULE,
 404                 .min_uV = LDO_A_VOLTAGE,
 405                 .enable_time = 200,
 406         },
 407         {
 408                 .name = "LDO_C",
 409                 .id   = AB3100_LDO_C,
 410                 .ops  = &regulator_ops_fixed,
 411                 .n_voltages = 1,
 412                 .type = REGULATOR_VOLTAGE,
 413                 .owner = THIS_MODULE,
 414                 .min_uV = LDO_C_VOLTAGE,
 415                 .enable_time = 200,
 416         },
 417         {
 418                 .name = "LDO_D",
 419                 .id   = AB3100_LDO_D,
 420                 .ops  = &regulator_ops_fixed,
 421                 .n_voltages = 1,
 422                 .type = REGULATOR_VOLTAGE,
 423                 .owner = THIS_MODULE,
 424                 .min_uV = LDO_D_VOLTAGE,
 425                 .enable_time = 200,
 426         },
 427         {
 428                 .name = "LDO_E",
 429                 .id   = AB3100_LDO_E,
 430                 .ops  = &regulator_ops_variable_sleepable,
 431                 .n_voltages = ARRAY_SIZE(ldo_e_buck_typ_voltages),
 432                 .volt_table = ldo_e_buck_typ_voltages,
 433                 .type = REGULATOR_VOLTAGE,
 434                 .owner = THIS_MODULE,
 435                 .enable_time = 200,
 436         },
 437         {
 438                 .name = "LDO_F",
 439                 .id   = AB3100_LDO_F,
 440                 .ops  = &regulator_ops_variable,
 441                 .n_voltages = ARRAY_SIZE(ldo_f_typ_voltages),
 442                 .volt_table = ldo_f_typ_voltages,
 443                 .type = REGULATOR_VOLTAGE,
 444                 .owner = THIS_MODULE,
 445                 .enable_time = 600,
 446         },
 447         {
 448                 .name = "LDO_G",
 449                 .id   = AB3100_LDO_G,
 450                 .ops  = &regulator_ops_variable,
 451                 .n_voltages = ARRAY_SIZE(ldo_g_typ_voltages),
 452                 .volt_table = ldo_g_typ_voltages,
 453                 .type = REGULATOR_VOLTAGE,
 454                 .owner = THIS_MODULE,
 455                 .enable_time = 400,
 456         },
 457         {
 458                 .name = "LDO_H",
 459                 .id   = AB3100_LDO_H,
 460                 .ops  = &regulator_ops_variable,
 461                 .n_voltages = ARRAY_SIZE(ldo_h_typ_voltages),
 462                 .volt_table = ldo_h_typ_voltages,
 463                 .type = REGULATOR_VOLTAGE,
 464                 .owner = THIS_MODULE,
 465                 .enable_time = 200,
 466         },
 467         {
 468                 .name = "LDO_K",
 469                 .id   = AB3100_LDO_K,
 470                 .ops  = &regulator_ops_variable,
 471                 .n_voltages = ARRAY_SIZE(ldo_k_typ_voltages),
 472                 .volt_table = ldo_k_typ_voltages,
 473                 .type = REGULATOR_VOLTAGE,
 474                 .owner = THIS_MODULE,
 475                 .enable_time = 200,
 476         },
 477         {
 478                 .name = "LDO_EXT",
 479                 .id   = AB3100_LDO_EXT,
 480                 .ops  = &regulator_ops_external,
 481                 .type = REGULATOR_VOLTAGE,
 482                 .owner = THIS_MODULE,
 483         },
 484         {
 485                 .name = "BUCK",
 486                 .id   = AB3100_BUCK,
 487                 .ops  = &regulator_ops_variable_sleepable,
 488                 .n_voltages = ARRAY_SIZE(ldo_e_buck_typ_voltages),
 489                 .type = REGULATOR_VOLTAGE,
 490                 .owner = THIS_MODULE,
 491                 .enable_time = 1000,
 492         },
 493 };
 494
 495 /*
 496  * NOTE: the following functions are regulators pluralis - it is the
 497  * binding to the AB3100 core driver and the parent platform device
 498  * for all the different regulators.
 499  */
 500
 501 static int __devinit ab3100_regulators_probe(struct platform_device *pdev)
 502 {
 503         struct ab3100_platform_data *plfdata = pdev->dev.platform_data;
 504         struct regulator_config config = { };
 505         int err = 0;
 506         u8 data;
 507         int i;
 508
 509         /* Check chip state */
 510         err = abx500_get_register_interruptible(&pdev->dev, 0,
 511                                                 AB3100_LDO_D, &data);
 512         if (err) {
 513                 dev_err(&pdev->dev, "could not read initial status of LDO_D\n");
 514                 return err;
 515         }
 516         if (data & 0x10)
 517                 dev_notice(&pdev->dev,
 518                            "chip is already in active mode (Warm start)\n");
 519         else
 520                 dev_notice(&pdev->dev,
 521                            "chip is in inactive mode (Cold start)\n");
 522
 523         /* Set up regulators */
 524         for (i = 0; i < ARRAY_SIZE(ab3100_reg_init_order); i++) {
 525                 err = abx500_set_register_interruptible(&pdev->dev, 0,
 526                                         ab3100_reg_init_order[i],
 527                                         plfdata->reg_initvals[i]);
 528                 if (err) {
 529                         dev_err(&pdev->dev, "regulator initialization failed with error %d\n",
 530                                 err);
 531                         return err;
 532                 }
 533         }
 534
 535         /* Register the regulators */
 536         for (i = 0; i < AB3100_NUM_REGULATORS; i++) {
 537                 struct ab3100_regulator *reg = &ab3100_regulators[i];
 538                 struct regulator_dev *rdev;
 539
 540                 /*
 541                  * Initialize per-regulator struct.
 542                  * Inherit platform data, this comes down from the
 543                  * i2c boarddata, from the machine. So if you want to
 544                  * see what it looks like for a certain machine, go
 545                  * into the machine I2C setup.
 546                  */
 547                 reg->dev = &pdev->dev;
 548                 reg->plfdata = plfdata;
 549
 550                 config.dev = &pdev->dev;
 551                 config.driver_data = reg;
 552                 config.init_data = &plfdata->reg_constraints[i];
 553
 554                 /*
 555                  * Register the regulator, pass around
 556                  * the ab3100_regulator struct
 557                  */
 558                 rdev = regulator_register(&ab3100_regulator_desc[i], &config);
 559                 if (IS_ERR(rdev)) {
 560                         err = PTR_ERR(rdev);
 561                         dev_err(&pdev->dev,
 562                                 "%s: failed to register regulator %s err %d\n",
 563                                 __func__, ab3100_regulator_desc[i].name,
 564                                 err);
 565                         /* remove the already registered regulators */
 566                         while (--i >= 0)
 567                                 regulator_unregister(ab3100_regulators[i].rdev);
 568                         return err;
 569                 }
 570
 571                 /* Then set a pointer back to the registered regulator */
 572                 reg->rdev = rdev;
 573         }
 574
 575         return 0;
 576 }
 577
 578 static int __devexit ab3100_regulators_remove(struct platform_device *pdev)
 579 {
 580         int i;
 581
 582         for (i = 0; i < AB3100_NUM_REGULATORS; i++) {
 583                 struct ab3100_regulator *reg = &ab3100_regulators[i];
 584
 585                 regulator_unregister(reg->rdev);
 586         }
 587         return 0;
 588 }
 589
 590 static struct platform_driver ab3100_regulators_driver = {
 591         .driver = {
 592                 .name  = "ab3100-regulators",
 593                 .owner = THIS_MODULE,
 594         },
 595         .probe = ab3100_regulators_probe,
 596         .remove = __devexit_p(ab3100_regulators_remove),
 597 };
 598
 599 static __init int ab3100_regulators_init(void)
 600 {
 601         return platform_driver_register(&ab3100_regulators_driver);
 602 }
 603
 604 static __exit void ab3100_regulators_exit(void)
 605 {
 606         platform_driver_unregister(&ab3100_regulators_driver);
 607 }
 608
 609 subsys_initcall(ab3100_regulators_init);
 610 module_exit(ab3100_regulators_exit);
 611
 612 MODULE_AUTHOR("Mattias Wallin <mattias.wallin@stericsson.com>");
 613 MODULE_DESCRIPTION("AB3100 Regulator driver");
 614 MODULE_LICENSE("GPL");
 615 MODULE_ALIAS("platform:ab3100-regulators");