drivers/regulator/max8660.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * max8660.c  --  Voltage regulation for the Maxim 8660/8661
   4  *
   5  * based on max1586.c and wm8400-regulator.c
   6  *
   7  * Copyright (C) 2009 Wolfram Sang, Pengutronix e.K.
   8  *
   9  * Some info:
  10  *
  11  * Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX8660-MAX8661.pdf
  12  *
  13  * This chip is a bit nasty because it is a write-only device. Thus, the driver
  14  * uses shadow registers to keep track of its values. The main problem appears
  15  * to be the initialization: When Linux boots up, we cannot know if the chip is
  16  * in the default state or not, so we would have to pass such information in
  17  * platform_data. As this adds a bit of complexity to the driver, this is left
  18  * out for now until it is really needed.
  19  *
  20  * [A|S|M]DTV1 registers are currently not used, but [A|S|M]DTV2.
  21  *
  22  * If the driver is feature complete, it might be worth to check if one set of
  23  * functions for V3-V7 is sufficient. For maximum flexibility during
  24  * development, they are separated for now.
  25  */
  26
  27 #include <linux/module.h>
  28 #include <linux/err.h>
  29 #include <linux/i2c.h>
  30 #include <linux/platform_device.h>
  31 #include <linux/regulator/driver.h>
  32 #include <linux/slab.h>
  33 #include <linux/regulator/max8660.h>
  34 #include <linux/of.h>
  35 #include <linux/of_device.h>
  36 #include <linux/regulator/of_regulator.h>
  37
  38 #define MAX8660_DCDC_MIN_UV      725000
  39 #define MAX8660_DCDC_MAX_UV     1800000
  40 #define MAX8660_DCDC_STEP         25000
  41 #define MAX8660_DCDC_MAX_SEL    0x2b
  42
  43 #define MAX8660_LDO5_MIN_UV     1700000
  44 #define MAX8660_LDO5_MAX_UV     2000000
  45 #define MAX8660_LDO5_STEP         25000
  46 #define MAX8660_LDO5_MAX_SEL    0x0c
  47
  48 #define MAX8660_LDO67_MIN_UV    1800000
  49 #define MAX8660_LDO67_MAX_UV    3300000
  50 #define MAX8660_LDO67_STEP       100000
  51 #define MAX8660_LDO67_MAX_SEL   0x0f
  52
  53 enum {
  54         MAX8660_OVER1,
  55         MAX8660_OVER2,
  56         MAX8660_VCC1,
  57         MAX8660_ADTV1,
  58         MAX8660_ADTV2,
  59         MAX8660_SDTV1,
  60         MAX8660_SDTV2,
  61         MAX8660_MDTV1,
  62         MAX8660_MDTV2,
  63         MAX8660_L12VCR,
  64         MAX8660_FPWM,
  65         MAX8660_N_REGS, /* not a real register */
  66 };
  67
  68 struct max8660 {
  69         struct i2c_client *client;
  70         u8 shadow_regs[MAX8660_N_REGS];         /* as chip is write only */
  71 };
  72
  73 static int max8660_write(struct max8660 *max8660, u8 reg, u8 mask, u8 val)
  74 {
  75         static const u8 max8660_addresses[MAX8660_N_REGS] = {
  76          0x10, 0x12, 0x20, 0x23, 0x24, 0x29, 0x2a, 0x32, 0x33, 0x39, 0x80
  77         };
  78
  79         int ret;
  80         u8 reg_val = (max8660->shadow_regs[reg] & mask) | val;
  81
  82         dev_vdbg(&max8660->client->dev, "Writing reg %02x with %02x\n",
  83                         max8660_addresses[reg], reg_val);
  84
  85         ret = i2c_smbus_write_byte_data(max8660->client,
  86                         max8660_addresses[reg], reg_val);
  87         if (ret == 0)
  88                 max8660->shadow_regs[reg] = reg_val;
  89
  90         return ret;
  91 }
  92
  93
  94 /*
  95  * DCDC functions
  96  */
  97
  98 static int max8660_dcdc_is_enabled(struct regulator_dev *rdev)
  99 {
 100         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 101         u8 val = max8660->shadow_regs[MAX8660_OVER1];
 102         u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4;
 103
 104         return !!(val & mask);
 105 }
 106
 107 static int max8660_dcdc_enable(struct regulator_dev *rdev)
 108 {
 109         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 110         u8 bit = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4;
 111
 112         return max8660_write(max8660, MAX8660_OVER1, 0xff, bit);
 113 }
 114
 115 static int max8660_dcdc_disable(struct regulator_dev *rdev)
 116 {
 117         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 118         u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? ~1 : ~4;
 119
 120         return max8660_write(max8660, MAX8660_OVER1, mask, 0);
 121 }
 122
 123 static int max8660_dcdc_get_voltage_sel(struct regulator_dev *rdev)
 124 {
 125         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 126         u8 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2;
 127         u8 selector = max8660->shadow_regs[reg];
 128
 129         return selector;
 130 }
 131
 132 static int max8660_dcdc_set_voltage_sel(struct regulator_dev *rdev,
 133                                         unsigned int selector)
 134 {
 135         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 136         u8 reg, bits;
 137         int ret;
 138
 139         reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2;
 140         ret = max8660_write(max8660, reg, 0, selector);
 141         if (ret)
 142                 return ret;
 143
 144         /* Select target voltage register and activate regulation */
 145         bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30;
 146         return max8660_write(max8660, MAX8660_VCC1, 0xff, bits);
 147 }
 148
 149 static struct regulator_ops max8660_dcdc_ops = {
 150         .is_enabled = max8660_dcdc_is_enabled,
 151         .list_voltage = regulator_list_voltage_linear,
 152         .map_voltage = regulator_map_voltage_linear,
 153         .set_voltage_sel = max8660_dcdc_set_voltage_sel,
 154         .get_voltage_sel = max8660_dcdc_get_voltage_sel,
 155 };
 156
 157
 158 /*
 159  * LDO5 functions
 160  */
 161
 162 static int max8660_ldo5_get_voltage_sel(struct regulator_dev *rdev)
 163 {
 164         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 165
 166         u8 selector = max8660->shadow_regs[MAX8660_MDTV2];
 167         return selector;
 168 }
 169
 170 static int max8660_ldo5_set_voltage_sel(struct regulator_dev *rdev,
 171                                         unsigned int selector)
 172 {
 173         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 174         int ret;
 175
 176         ret = max8660_write(max8660, MAX8660_MDTV2, 0, selector);
 177         if (ret)
 178                 return ret;
 179
 180         /* Select target voltage register and activate regulation */
 181         return max8660_write(max8660, MAX8660_VCC1, 0xff, 0xc0);
 182 }
 183
 184 static const struct regulator_ops max8660_ldo5_ops = {
 185         .list_voltage = regulator_list_voltage_linear,
 186         .map_voltage = regulator_map_voltage_linear,
 187         .set_voltage_sel = max8660_ldo5_set_voltage_sel,
 188         .get_voltage_sel = max8660_ldo5_get_voltage_sel,
 189 };
 190
 191
 192 /*
 193  * LDO67 functions
 194  */
 195
 196 static int max8660_ldo67_is_enabled(struct regulator_dev *rdev)
 197 {
 198         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 199         u8 val = max8660->shadow_regs[MAX8660_OVER2];
 200         u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
 201
 202         return !!(val & mask);
 203 }
 204
 205 static int max8660_ldo67_enable(struct regulator_dev *rdev)
 206 {
 207         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 208         u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
 209
 210         return max8660_write(max8660, MAX8660_OVER2, 0xff, bit);
 211 }
 212
 213 static int max8660_ldo67_disable(struct regulator_dev *rdev)
 214 {
 215         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 216         u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4;
 217
 218         return max8660_write(max8660, MAX8660_OVER2, mask, 0);
 219 }
 220
 221 static int max8660_ldo67_get_voltage_sel(struct regulator_dev *rdev)
 222 {
 223         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 224         u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4;
 225         u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf;
 226
 227         return selector;
 228 }
 229
 230 static int max8660_ldo67_set_voltage_sel(struct regulator_dev *rdev,
 231                                          unsigned int selector)
 232 {
 233         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 234
 235         if (rdev_get_id(rdev) == MAX8660_V6)
 236                 return max8660_write(max8660, MAX8660_L12VCR, 0xf0, selector);
 237         else
 238                 return max8660_write(max8660, MAX8660_L12VCR, 0x0f,
 239                                      selector << 4);
 240 }
 241
 242 static const struct regulator_ops max8660_ldo67_ops = {
 243         .is_enabled = max8660_ldo67_is_enabled,
 244         .enable = max8660_ldo67_enable,
 245         .disable = max8660_ldo67_disable,
 246         .list_voltage = regulator_list_voltage_linear,
 247         .map_voltage = regulator_map_voltage_linear,
 248         .get_voltage_sel = max8660_ldo67_get_voltage_sel,
 249         .set_voltage_sel = max8660_ldo67_set_voltage_sel,
 250 };
 251
 252 static const struct regulator_desc max8660_reg[] = {
 253         {
 254                 .name = "V3(DCDC)",
 255                 .id = MAX8660_V3,
 256                 .ops = &max8660_dcdc_ops,
 257                 .type = REGULATOR_VOLTAGE,
 258                 .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
 259                 .owner = THIS_MODULE,
 260                 .min_uV = MAX8660_DCDC_MIN_UV,
 261                 .uV_step = MAX8660_DCDC_STEP,
 262         },
 263         {
 264                 .name = "V4(DCDC)",
 265                 .id = MAX8660_V4,
 266                 .ops = &max8660_dcdc_ops,
 267                 .type = REGULATOR_VOLTAGE,
 268                 .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
 269                 .owner = THIS_MODULE,
 270                 .min_uV = MAX8660_DCDC_MIN_UV,
 271                 .uV_step = MAX8660_DCDC_STEP,
 272         },
 273         {
 274                 .name = "V5(LDO)",
 275                 .id = MAX8660_V5,
 276                 .ops = &max8660_ldo5_ops,
 277                 .type = REGULATOR_VOLTAGE,
 278                 .n_voltages = MAX8660_LDO5_MAX_SEL + 1,
 279                 .owner = THIS_MODULE,
 280                 .min_uV = MAX8660_LDO5_MIN_UV,
 281                 .uV_step = MAX8660_LDO5_STEP,
 282         },
 283         {
 284                 .name = "V6(LDO)",
 285                 .id = MAX8660_V6,
 286                 .ops = &max8660_ldo67_ops,
 287                 .type = REGULATOR_VOLTAGE,
 288                 .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
 289                 .owner = THIS_MODULE,
 290                 .min_uV = MAX8660_LDO67_MIN_UV,
 291                 .uV_step = MAX8660_LDO67_STEP,
 292         },
 293         {
 294                 .name = "V7(LDO)",
 295                 .id = MAX8660_V7,
 296                 .ops = &max8660_ldo67_ops,
 297                 .type = REGULATOR_VOLTAGE,
 298                 .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
 299                 .owner = THIS_MODULE,
 300                 .min_uV = MAX8660_LDO67_MIN_UV,
 301                 .uV_step = MAX8660_LDO67_STEP,
 302         },
 303 };
 304
 305 enum {
 306         MAX8660 = 0,
 307         MAX8661 = 1,
 308 };
 309
 310 #ifdef CONFIG_OF
 311 static const struct of_device_id max8660_dt_ids[] = {
 312         { .compatible = "maxim,max8660", .data = (void *) MAX8660 },
 313         { .compatible = "maxim,max8661", .data = (void *) MAX8661 },
 314         { }
 315 };
 316 MODULE_DEVICE_TABLE(of, max8660_dt_ids);
 317
 318 static int max8660_pdata_from_dt(struct device *dev,
 319                                  struct device_node **of_node,
 320                                  struct max8660_platform_data *pdata)
 321 {
 322         int matched, i;
 323         struct device_node *np;
 324         struct max8660_subdev_data *sub;
 325         struct of_regulator_match rmatch[ARRAY_SIZE(max8660_reg)] = { };
 326
 327         np = of_get_child_by_name(dev->of_node, "regulators");
 328         if (!np) {
 329                 dev_err(dev, "missing 'regulators' subnode in DT\n");
 330                 return -EINVAL;
 331         }
 332
 333         for (i = 0; i < ARRAY_SIZE(rmatch); i++)
 334                 rmatch[i].name = max8660_reg[i].name;
 335
 336         matched = of_regulator_match(dev, np, rmatch, ARRAY_SIZE(rmatch));
 337         of_node_put(np);
 338         if (matched <= 0)
 339                 return matched;
 340
 341         pdata->subdevs = devm_kcalloc(dev,
 342                                       matched,
 343                                       sizeof(struct max8660_subdev_data),
 344                                       GFP_KERNEL);
 345         if (!pdata->subdevs)
 346                 return -ENOMEM;
 347
 348         pdata->num_subdevs = matched;
 349         sub = pdata->subdevs;
 350
 351         for (i = 0; i < matched; i++) {
 352                 sub->id = i;
 353                 sub->name = rmatch[i].name;
 354                 sub->platform_data = rmatch[i].init_data;
 355                 of_node[i] = rmatch[i].of_node;
 356                 sub++;
 357         }
 358
 359         return 0;
 360 }
 361 #else
 362 static inline int max8660_pdata_from_dt(struct device *dev,
 363                                         struct device_node **of_node,
 364                                         struct max8660_platform_data *pdata)
 365 {
 366         return 0;
 367 }
 368 #endif
 369
 370 static int max8660_probe(struct i2c_client *client,
 371                                    const struct i2c_device_id *i2c_id)
 372 {
 373         struct device *dev = &client->dev;
 374         struct max8660_platform_data pdata_of, *pdata = dev_get_platdata(dev);
 375         struct regulator_config config = { };
 376         struct max8660 *max8660;
 377         int boot_on, i, id, ret = -EINVAL;
 378         struct device_node *of_node[MAX8660_V_END];
 379         unsigned long type;
 380
 381         if (dev->of_node && !pdata) {
 382                 const struct of_device_id *id;
 383
 384                 id = of_match_device(of_match_ptr(max8660_dt_ids), dev);
 385                 if (!id)
 386                         return -ENODEV;
 387
 388                 ret = max8660_pdata_from_dt(dev, of_node, &pdata_of);
 389                 if (ret < 0)
 390                         return ret;
 391
 392                 pdata = &pdata_of;
 393                 type = (unsigned long) id->data;
 394         } else {
 395                 type = i2c_id->driver_data;
 396                 memset(of_node, 0, sizeof(of_node));
 397         }
 398
 399         if (pdata->num_subdevs > MAX8660_V_END) {
 400                 dev_err(dev, "Too many regulators found!\n");
 401                 return -EINVAL;
 402         }
 403
 404         max8660 = devm_kzalloc(dev, sizeof(struct max8660), GFP_KERNEL);
 405         if (!max8660)
 406                 return -ENOMEM;
 407
 408         max8660->client = client;
 409
 410         if (pdata->en34_is_high) {
 411                 /* Simulate always on */
 412                 max8660->shadow_regs[MAX8660_OVER1] = 5;
 413         } else {
 414                 /* Otherwise devices can be toggled via software */
 415                 max8660_dcdc_ops.enable = max8660_dcdc_enable;
 416                 max8660_dcdc_ops.disable = max8660_dcdc_disable;
 417         }
 418
 419         /*
 420          * First, set up shadow registers to prevent glitches. As some
 421          * registers are shared between regulators, everything must be properly
 422          * set up for all regulators in advance.
 423          */
 424         max8660->shadow_regs[MAX8660_ADTV1] =
 425                 max8660->shadow_regs[MAX8660_ADTV2] =
 426                 max8660->shadow_regs[MAX8660_SDTV1] =
 427                 max8660->shadow_regs[MAX8660_SDTV2] = 0x1b;
 428         max8660->shadow_regs[MAX8660_MDTV1] =
 429                 max8660->shadow_regs[MAX8660_MDTV2] = 0x04;
 430
 431         for (i = 0; i < pdata->num_subdevs; i++) {
 432
 433                 if (!pdata->subdevs[i].platform_data)
 434                         boot_on = false;
 435                 else
 436                         boot_on = pdata->subdevs[i].platform_data->constraints.boot_on;
 437
 438                 switch (pdata->subdevs[i].id) {
 439                 case MAX8660_V3:
 440                         if (boot_on)
 441                                 max8660->shadow_regs[MAX8660_OVER1] |= 1;
 442                         break;
 443
 444                 case MAX8660_V4:
 445                         if (boot_on)
 446                                 max8660->shadow_regs[MAX8660_OVER1] |= 4;
 447                         break;
 448
 449                 case MAX8660_V5:
 450                         break;
 451
 452                 case MAX8660_V6:
 453                         if (boot_on)
 454                                 max8660->shadow_regs[MAX8660_OVER2] |= 2;
 455                         break;
 456
 457                 case MAX8660_V7:
 458                         if (type == MAX8661) {
 459                                 dev_err(dev, "Regulator not on this chip!\n");
 460                                 return -EINVAL;
 461                         }
 462
 463                         if (boot_on)
 464                                 max8660->shadow_regs[MAX8660_OVER2] |= 4;
 465                         break;
 466
 467                 default:
 468                         dev_err(dev, "invalid regulator %s\n",
 469                                  pdata->subdevs[i].name);
 470                         return ret;
 471                 }
 472         }
 473
 474         /* Finally register devices */
 475         for (i = 0; i < pdata->num_subdevs; i++) {
 476                 struct regulator_dev *rdev;
 477
 478                 id = pdata->subdevs[i].id;
 479
 480                 config.dev = dev;
 481                 config.init_data = pdata->subdevs[i].platform_data;
 482                 config.of_node = of_node[i];
 483                 config.driver_data = max8660;
 484
 485                 rdev = devm_regulator_register(&client->dev,
 486                                                   &max8660_reg[id], &config);
 487                 if (IS_ERR(rdev)) {
 488                         dev_err(&client->dev, "failed to register %s\n",
 489                                 max8660_reg[id].name);
 490                         return PTR_ERR(rdev);
 491                 }
 492         }
 493
 494         i2c_set_clientdata(client, max8660);
 495         return 0;
 496 }
 497
 498 static const struct i2c_device_id max8660_id[] = {
 499         { .name = "max8660", .driver_data = MAX8660 },
 500         { .name = "max8661", .driver_data = MAX8661 },
 501         { }
 502 };
 503 MODULE_DEVICE_TABLE(i2c, max8660_id);
 504
 505 static struct i2c_driver max8660_driver = {
 506         .probe = max8660_probe,
 507         .driver         = {
 508                 .name   = "max8660",
 509         },
 510         .id_table       = max8660_id,
 511 };
 512
 513 static int __init max8660_init(void)
 514 {
 515         return i2c_add_driver(&max8660_driver);
 516 }
 517 subsys_initcall(max8660_init);
 518
 519 static void __exit max8660_exit(void)
 520 {
 521         i2c_del_driver(&max8660_driver);
 522 }
 523 module_exit(max8660_exit);
 524
 525 /* Module information */
 526 MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver");
 527 MODULE_AUTHOR("Wolfram Sang");
 528 MODULE_LICENSE("GPL v2");