drivers/regulator/max8660.c

   1 /*
   2  * max8660.c  --  Voltage regulation for the Maxim 8660/8661
   3  *
   4  * based on max1586.c and wm8400-regulator.c
   5  *
   6  * Copyright (C) 2009 Wolfram Sang, Pengutronix e.K.
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by the Free
  10  * Software Foundation; version 2 of the License.
  11  *
  12  * This program is distributed in the hope that it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  15  * more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along with
  18  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  19  * Place, Suite 330, Boston, MA  02111-1307  USA
  20  *
  21  * Some info:
  22  *
  23  * Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX8660-MAX8661.pdf
  24  *
  25  * This chip is a bit nasty because it is a write-only device. Thus, the driver
  26  * uses shadow registers to keep track of its values. The main problem appears
  27  * to be the initialization: When Linux boots up, we cannot know if the chip is
  28  * in the default state or not, so we would have to pass such information in
  29  * platform_data. As this adds a bit of complexity to the driver, this is left
  30  * out for now until it is really needed.
  31  *
  32  * [A|S|M]DTV1 registers are currently not used, but [A|S|M]DTV2.
  33  *
  34  * If the driver is feature complete, it might be worth to check if one set of
  35  * functions for V3-V7 is sufficient. For maximum flexibility during
  36  * development, they are separated for now.
  37  *
  38  */
  39
  40 #include <linux/module.h>
  41 #include <linux/err.h>
  42 #include <linux/i2c.h>
  43 #include <linux/platform_device.h>
  44 #include <linux/regulator/driver.h>
  45 #include <linux/slab.h>
  46 #include <linux/regulator/max8660.h>
  47 #include <linux/of.h>
  48 #include <linux/of_device.h>
  49 #include <linux/regulator/of_regulator.h>
  50
  51 #define MAX8660_DCDC_MIN_UV      725000
  52 #define MAX8660_DCDC_MAX_UV     1800000
  53 #define MAX8660_DCDC_STEP         25000
  54 #define MAX8660_DCDC_MAX_SEL    0x2b
  55
  56 #define MAX8660_LDO5_MIN_UV     1700000
  57 #define MAX8660_LDO5_MAX_UV     2000000
  58 #define MAX8660_LDO5_STEP         25000
  59 #define MAX8660_LDO5_MAX_SEL    0x0c
  60
  61 #define MAX8660_LDO67_MIN_UV    1800000
  62 #define MAX8660_LDO67_MAX_UV    3300000
  63 #define MAX8660_LDO67_STEP       100000
  64 #define MAX8660_LDO67_MAX_SEL   0x0f
  65
  66 enum {
  67         MAX8660_OVER1,
  68         MAX8660_OVER2,
  69         MAX8660_VCC1,
  70         MAX8660_ADTV1,
  71         MAX8660_ADTV2,
  72         MAX8660_SDTV1,
  73         MAX8660_SDTV2,
  74         MAX8660_MDTV1,
  75         MAX8660_MDTV2,
  76         MAX8660_L12VCR,
  77         MAX8660_FPWM,
  78         MAX8660_N_REGS, /* not a real register */
  79 };
  80
  81 struct max8660 {
  82         struct i2c_client *client;
  83         u8 shadow_regs[MAX8660_N_REGS];         /* as chip is write only */
  84 };
  85
  86 static int max8660_write(struct max8660 *max8660, u8 reg, u8 mask, u8 val)
  87 {
  88         static const u8 max8660_addresses[MAX8660_N_REGS] = {
  89          0x10, 0x12, 0x20, 0x23, 0x24, 0x29, 0x2a, 0x32, 0x33, 0x39, 0x80
  90         };
  91
  92         int ret;
  93         u8 reg_val = (max8660->shadow_regs[reg] & mask) | val;
  94
  95         dev_vdbg(&max8660->client->dev, "Writing reg %02x with %02x\n",
  96                         max8660_addresses[reg], reg_val);
  97
  98         ret = i2c_smbus_write_byte_data(max8660->client,
  99                         max8660_addresses[reg], reg_val);
 100         if (ret == 0)
 101                 max8660->shadow_regs[reg] = reg_val;
 102
 103         return ret;
 104 }
 105
 106
 107 /*
 108  * DCDC functions
 109  */
 110
 111 static int max8660_dcdc_is_enabled(struct regulator_dev *rdev)
 112 {
 113         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 114         u8 val = max8660->shadow_regs[MAX8660_OVER1];
 115         u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4;
 116
 117         return !!(val & mask);
 118 }
 119
 120 static int max8660_dcdc_enable(struct regulator_dev *rdev)
 121 {
 122         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 123         u8 bit = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4;
 124
 125         return max8660_write(max8660, MAX8660_OVER1, 0xff, bit);
 126 }
 127
 128 static int max8660_dcdc_disable(struct regulator_dev *rdev)
 129 {
 130         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 131         u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? ~1 : ~4;
 132
 133         return max8660_write(max8660, MAX8660_OVER1, mask, 0);
 134 }
 135
 136 static int max8660_dcdc_get_voltage_sel(struct regulator_dev *rdev)
 137 {
 138         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 139         u8 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2;
 140         u8 selector = max8660->shadow_regs[reg];
 141
 142         return selector;
 143 }
 144
 145 static int max8660_dcdc_set_voltage_sel(struct regulator_dev *rdev,
 146                                         unsigned int selector)
 147 {
 148         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 149         u8 reg, bits;
 150         int ret;
 151
 152         reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2;
 153         ret = max8660_write(max8660, reg, 0, selector);
 154         if (ret)
 155                 return ret;
 156
 157         /* Select target voltage register and activate regulation */
 158         bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30;
 159         return max8660_write(max8660, MAX8660_VCC1, 0xff, bits);
 160 }
 161
 162 static struct regulator_ops max8660_dcdc_ops = {
 163         .is_enabled = max8660_dcdc_is_enabled,
 164         .list_voltage = regulator_list_voltage_linear,
 165         .map_voltage = regulator_map_voltage_linear,
 166         .set_voltage_sel = max8660_dcdc_set_voltage_sel,
 167         .get_voltage_sel = max8660_dcdc_get_voltage_sel,
 168 };
 169
 170
 171 /*
 172  * LDO5 functions
 173  */
 174
 175 static int max8660_ldo5_get_voltage_sel(struct regulator_dev *rdev)
 176 {
 177         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 178
 179         u8 selector = max8660->shadow_regs[MAX8660_MDTV2];
 180         return selector;
 181 }
 182
 183 static int max8660_ldo5_set_voltage_sel(struct regulator_dev *rdev,
 184                                         unsigned int selector)
 185 {
 186         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 187         int ret;
 188
 189         ret = max8660_write(max8660, MAX8660_MDTV2, 0, selector);
 190         if (ret)
 191                 return ret;
 192
 193         /* Select target voltage register and activate regulation */
 194         return max8660_write(max8660, MAX8660_VCC1, 0xff, 0xc0);
 195 }
 196
 197 static const struct regulator_ops max8660_ldo5_ops = {
 198         .list_voltage = regulator_list_voltage_linear,
 199         .map_voltage = regulator_map_voltage_linear,
 200         .set_voltage_sel = max8660_ldo5_set_voltage_sel,
 201         .get_voltage_sel = max8660_ldo5_get_voltage_sel,
 202 };
 203
 204
 205 /*
 206  * LDO67 functions
 207  */
 208
 209 static int max8660_ldo67_is_enabled(struct regulator_dev *rdev)
 210 {
 211         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 212         u8 val = max8660->shadow_regs[MAX8660_OVER2];
 213         u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
 214
 215         return !!(val & mask);
 216 }
 217
 218 static int max8660_ldo67_enable(struct regulator_dev *rdev)
 219 {
 220         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 221         u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
 222
 223         return max8660_write(max8660, MAX8660_OVER2, 0xff, bit);
 224 }
 225
 226 static int max8660_ldo67_disable(struct regulator_dev *rdev)
 227 {
 228         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 229         u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4;
 230
 231         return max8660_write(max8660, MAX8660_OVER2, mask, 0);
 232 }
 233
 234 static int max8660_ldo67_get_voltage_sel(struct regulator_dev *rdev)
 235 {
 236         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 237         u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4;
 238         u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf;
 239
 240         return selector;
 241 }
 242
 243 static int max8660_ldo67_set_voltage_sel(struct regulator_dev *rdev,
 244                                          unsigned int selector)
 245 {
 246         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 247
 248         if (rdev_get_id(rdev) == MAX8660_V6)
 249                 return max8660_write(max8660, MAX8660_L12VCR, 0xf0, selector);
 250         else
 251                 return max8660_write(max8660, MAX8660_L12VCR, 0x0f,
 252                                      selector << 4);
 253 }
 254
 255 static const struct regulator_ops max8660_ldo67_ops = {
 256         .is_enabled = max8660_ldo67_is_enabled,
 257         .enable = max8660_ldo67_enable,
 258         .disable = max8660_ldo67_disable,
 259         .list_voltage = regulator_list_voltage_linear,
 260         .map_voltage = regulator_map_voltage_linear,
 261         .get_voltage_sel = max8660_ldo67_get_voltage_sel,
 262         .set_voltage_sel = max8660_ldo67_set_voltage_sel,
 263 };
 264
 265 static const struct regulator_desc max8660_reg[] = {
 266         {
 267                 .name = "V3(DCDC)",
 268                 .id = MAX8660_V3,
 269                 .ops = &max8660_dcdc_ops,
 270                 .type = REGULATOR_VOLTAGE,
 271                 .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
 272                 .owner = THIS_MODULE,
 273                 .min_uV = MAX8660_DCDC_MIN_UV,
 274                 .uV_step = MAX8660_DCDC_STEP,
 275         },
 276         {
 277                 .name = "V4(DCDC)",
 278                 .id = MAX8660_V4,
 279                 .ops = &max8660_dcdc_ops,
 280                 .type = REGULATOR_VOLTAGE,
 281                 .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
 282                 .owner = THIS_MODULE,
 283                 .min_uV = MAX8660_DCDC_MIN_UV,
 284                 .uV_step = MAX8660_DCDC_STEP,
 285         },
 286         {
 287                 .name = "V5(LDO)",
 288                 .id = MAX8660_V5,
 289                 .ops = &max8660_ldo5_ops,
 290                 .type = REGULATOR_VOLTAGE,
 291                 .n_voltages = MAX8660_LDO5_MAX_SEL + 1,
 292                 .owner = THIS_MODULE,
 293                 .min_uV = MAX8660_LDO5_MIN_UV,
 294                 .uV_step = MAX8660_LDO5_STEP,
 295         },
 296         {
 297                 .name = "V6(LDO)",
 298                 .id = MAX8660_V6,
 299                 .ops = &max8660_ldo67_ops,
 300                 .type = REGULATOR_VOLTAGE,
 301                 .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
 302                 .owner = THIS_MODULE,
 303                 .min_uV = MAX8660_LDO67_MIN_UV,
 304                 .uV_step = MAX8660_LDO67_STEP,
 305         },
 306         {
 307                 .name = "V7(LDO)",
 308                 .id = MAX8660_V7,
 309                 .ops = &max8660_ldo67_ops,
 310                 .type = REGULATOR_VOLTAGE,
 311                 .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
 312                 .owner = THIS_MODULE,
 313                 .min_uV = MAX8660_LDO67_MIN_UV,
 314                 .uV_step = MAX8660_LDO67_STEP,
 315         },
 316 };
 317
 318 enum {
 319         MAX8660 = 0,
 320         MAX8661 = 1,
 321 };
 322
 323 #ifdef CONFIG_OF
 324 static const struct of_device_id max8660_dt_ids[] = {
 325         { .compatible = "maxim,max8660", .data = (void *) MAX8660 },
 326         { .compatible = "maxim,max8661", .data = (void *) MAX8661 },
 327         { }
 328 };
 329 MODULE_DEVICE_TABLE(of, max8660_dt_ids);
 330
 331 static int max8660_pdata_from_dt(struct device *dev,
 332                                  struct device_node **of_node,
 333                                  struct max8660_platform_data *pdata)
 334 {
 335         int matched, i;
 336         struct device_node *np;
 337         struct max8660_subdev_data *sub;
 338         struct of_regulator_match rmatch[ARRAY_SIZE(max8660_reg)] = { };
 339
 340         np = of_get_child_by_name(dev->of_node, "regulators");
 341         if (!np) {
 342                 dev_err(dev, "missing 'regulators' subnode in DT\n");
 343                 return -EINVAL;
 344         }
 345
 346         for (i = 0; i < ARRAY_SIZE(rmatch); i++)
 347                 rmatch[i].name = max8660_reg[i].name;
 348
 349         matched = of_regulator_match(dev, np, rmatch, ARRAY_SIZE(rmatch));
 350         of_node_put(np);
 351         if (matched <= 0)
 352                 return matched;
 353
 354         pdata->subdevs = devm_kzalloc(dev, sizeof(struct max8660_subdev_data) *
 355                                                 matched, GFP_KERNEL);
 356         if (!pdata->subdevs)
 357                 return -ENOMEM;
 358
 359         pdata->num_subdevs = matched;
 360         sub = pdata->subdevs;
 361
 362         for (i = 0; i < matched; i++) {
 363                 sub->id = i;
 364                 sub->name = rmatch[i].name;
 365                 sub->platform_data = rmatch[i].init_data;
 366                 of_node[i] = rmatch[i].of_node;
 367                 sub++;
 368         }
 369
 370         return 0;
 371 }
 372 #else
 373 static inline int max8660_pdata_from_dt(struct device *dev,
 374                                         struct device_node **of_node,
 375                                         struct max8660_platform_data *pdata)
 376 {
 377         return 0;
 378 }
 379 #endif
 380
 381 static int max8660_probe(struct i2c_client *client,
 382                                    const struct i2c_device_id *i2c_id)
 383 {
 384         struct device *dev = &client->dev;
 385         struct max8660_platform_data pdata_of, *pdata = dev_get_platdata(dev);
 386         struct regulator_config config = { };
 387         struct max8660 *max8660;
 388         int boot_on, i, id, ret = -EINVAL;
 389         struct device_node *of_node[MAX8660_V_END];
 390         unsigned long type;
 391
 392         if (dev->of_node && !pdata) {
 393                 const struct of_device_id *id;
 394
 395                 id = of_match_device(of_match_ptr(max8660_dt_ids), dev);
 396                 if (!id)
 397                         return -ENODEV;
 398
 399                 ret = max8660_pdata_from_dt(dev, of_node, &pdata_of);
 400                 if (ret < 0)
 401                         return ret;
 402
 403                 pdata = &pdata_of;
 404                 type = (unsigned long) id->data;
 405         } else {
 406                 type = i2c_id->driver_data;
 407                 memset(of_node, 0, sizeof(of_node));
 408         }
 409
 410         if (pdata->num_subdevs > MAX8660_V_END) {
 411                 dev_err(dev, "Too many regulators found!\n");
 412                 return -EINVAL;
 413         }
 414
 415         max8660 = devm_kzalloc(dev, sizeof(struct max8660), GFP_KERNEL);
 416         if (!max8660)
 417                 return -ENOMEM;
 418
 419         max8660->client = client;
 420
 421         if (pdata->en34_is_high) {
 422                 /* Simulate always on */
 423                 max8660->shadow_regs[MAX8660_OVER1] = 5;
 424         } else {
 425                 /* Otherwise devices can be toggled via software */
 426                 max8660_dcdc_ops.enable = max8660_dcdc_enable;
 427                 max8660_dcdc_ops.disable = max8660_dcdc_disable;
 428         }
 429
 430         /*
 431          * First, set up shadow registers to prevent glitches. As some
 432          * registers are shared between regulators, everything must be properly
 433          * set up for all regulators in advance.
 434          */
 435         max8660->shadow_regs[MAX8660_ADTV1] =
 436                 max8660->shadow_regs[MAX8660_ADTV2] =
 437                 max8660->shadow_regs[MAX8660_SDTV1] =
 438                 max8660->shadow_regs[MAX8660_SDTV2] = 0x1b;
 439         max8660->shadow_regs[MAX8660_MDTV1] =
 440                 max8660->shadow_regs[MAX8660_MDTV2] = 0x04;
 441
 442         for (i = 0; i < pdata->num_subdevs; i++) {
 443
 444                 if (!pdata->subdevs[i].platform_data)
 445                         boot_on = false;
 446                 else
 447                         boot_on = pdata->subdevs[i].platform_data->constraints.boot_on;
 448
 449                 switch (pdata->subdevs[i].id) {
 450                 case MAX8660_V3:
 451                         if (boot_on)
 452                                 max8660->shadow_regs[MAX8660_OVER1] |= 1;
 453                         break;
 454
 455                 case MAX8660_V4:
 456                         if (boot_on)
 457                                 max8660->shadow_regs[MAX8660_OVER1] |= 4;
 458                         break;
 459
 460                 case MAX8660_V5:
 461                         break;
 462
 463                 case MAX8660_V6:
 464                         if (boot_on)
 465                                 max8660->shadow_regs[MAX8660_OVER2] |= 2;
 466                         break;
 467
 468                 case MAX8660_V7:
 469                         if (type == MAX8661) {
 470                                 dev_err(dev, "Regulator not on this chip!\n");
 471                                 return -EINVAL;
 472                         }
 473
 474                         if (boot_on)
 475                                 max8660->shadow_regs[MAX8660_OVER2] |= 4;
 476                         break;
 477
 478                 default:
 479                         dev_err(dev, "invalid regulator %s\n",
 480                                  pdata->subdevs[i].name);
 481                         return ret;
 482                 }
 483         }
 484
 485         /* Finally register devices */
 486         for (i = 0; i < pdata->num_subdevs; i++) {
 487                 struct regulator_dev *rdev;
 488
 489                 id = pdata->subdevs[i].id;
 490
 491                 config.dev = dev;
 492                 config.init_data = pdata->subdevs[i].platform_data;
 493                 config.of_node = of_node[i];
 494                 config.driver_data = max8660;
 495
 496                 rdev = devm_regulator_register(&client->dev,
 497                                                   &max8660_reg[id], &config);
 498                 if (IS_ERR(rdev)) {
 499                         ret = PTR_ERR(rdev);
 500                         dev_err(&client->dev, "failed to register %s\n",
 501                                 max8660_reg[id].name);
 502                         return PTR_ERR(rdev);
 503                 }
 504         }
 505
 506         i2c_set_clientdata(client, max8660);
 507         return 0;
 508 }
 509
 510 static const struct i2c_device_id max8660_id[] = {
 511         { .name = "max8660", .driver_data = MAX8660 },
 512         { .name = "max8661", .driver_data = MAX8661 },
 513         { }
 514 };
 515 MODULE_DEVICE_TABLE(i2c, max8660_id);
 516
 517 static struct i2c_driver max8660_driver = {
 518         .probe = max8660_probe,
 519         .driver         = {
 520                 .name   = "max8660",
 521         },
 522         .id_table       = max8660_id,
 523 };
 524
 525 static int __init max8660_init(void)
 526 {
 527         return i2c_add_driver(&max8660_driver);
 528 }
 529 subsys_initcall(max8660_init);
 530
 531 static void __exit max8660_exit(void)
 532 {
 533         i2c_del_driver(&max8660_driver);
 534 }
 535 module_exit(max8660_exit);
 536
 537 /* Module information */
 538 MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver");
 539 MODULE_AUTHOR("Wolfram Sang");
 540 MODULE_LICENSE("GPL v2");